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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/934,400, filed Jun. 13, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to lamps and methods and systems involving leveling lampshades.
2. Description of Background
Lampshades are commonly used on lamps and lighting fixtures for decoration and for directing light in a particular direction. Often lampshades are attached to a lamp with a fastener. The components of lamps are often made of metal that can be bent out of shape if subjected to a force resulting from a fall or from a blow. If a component of a lamp is bent out of shape, the lampshade may not be level to a table or floor. Thus, it is desirable to limit the effects on lamp components when subjected to a force, and to allow for a lampshade to automatically adjust to being level if the lamp components are bent.
SUMMARY OF THE INVENTION
Systems and methods involving leveling lampshades are provided. In this regard, an exemplary embodiment comprises a system for leveling a lampshade comprising, a pivot member operative to engage a post of a lamp harp and support a spyder portion of a lampshade, and a retaining member operative to engage the post and induce a force on the spyder portion.
An embodiment comprises a lamp comprising, a harp having a post, a pivot member engaging the harp operative to support a spyder portion of a lampshade, and a retaining member operative to engage the post and exert a force on the spyder portion.
A method of assembling a lampshade leveling system, the method comprising, placing a spyder portion of a lampshade on a pivot member, placing a damper in a cavity of the spyder portion, threading a retaining member onto a post of a lamp harp.
Other systems, methods, features, and/or advantages of the present invention will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and protected by the accompanying claims.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIGS. 1 a and 1 b are side partially cutaway views illustrating an exemplary embodiment of a lampshade leveling system.
FIGS. 2 a and 2 b are side partially cutaway views illustrating an alternate exemplary embodiment of a lampshade leveling system.
FIGS. 3 a and 3 b are side partially cutaway views illustrating another alternate exemplary embodiment of a lamp and a lampshade leveling system.
FIG. 4 is a side view illustrating an exemplary embodiment of an alternate embodiment of a harp of a lampshade leveling system.
FIGS. 5 a and 5 b are side partially cutaway views illustrating of another alternate exemplary embodiment of a lampshade leveling system.
The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Systems and methods involving leveling lampshades are provided. Referring now in detail to the drawings, FIG. 1 a is a side partially cutaway view illustrating an exemplary embodiment of a lampshade leveling system 100 .
The lampshade leveling system 100 comprises a finial 102 , a retaining member 104 , a damper 106 , a spyder 108 , a pivot member 110 , a lampshade 112 , a post 114 , and a harp 116 .
FIG. 1 b is a side partially cutaway view illustrating the assembled lampshade leveling system 100 . The lampshade leveling system 100 is assembled by placing the pivot member 110 over the post 114 that is connected to the harp 116 . The pivot member 110 has a cavity that is a diameter that is greater than the diameter of the post 114 . The post 114 engages the cavity and extends through the pivot 110 member such that threads of the post 114 are exposed. The pivot member has an outer profile that is curved.
The lampshade 112 is placed on the post 114 by placing a center cavity of the spyder 108 over the post 114 . A bottom surface of the spyder 108 rests on the curved profile of the pivot member 110 . In the illustrated embodiment, the damper 106 is placed over the post 114 and rests on the curved profile of the pivot member and in the center cavity of the spyder 108 . The damper 106 in the illustrated embodiment is an O-ring, however other types of elastic or malleable dampers may be used, including multiple dampers 106 . The embodiment is not limited to O-rings and may include any suitable damping material. Alternate embodiments may not include a damper 106 .
The retaining member 104 has a cavity 105 that may be threaded and engages threads of the post 114 . A bottom surface of the retaining member 104 contacts the damper 106 . The finial 102 may be attached to a threaded post 103 of the retaining member 104 and engages the threaded portion threaded post 103 with a threaded cavity 101 . The retaining member 104 may include a flange portion 107 having an outer diameter.
In operation, when a force is implied on the lampshade 112 , the spyder 108 pivots on the pivot member 110 . The pivot member 110 may remain substantially stationary relative to the motion of the spyder 108 . The post 114 and the harp 116 also may remain stationary. Thus, the spyder 108 pivots relative to the post 114 and the harp 116 . The force of gravity eventually returns the lampshade 112 to a position level with a table or floor.
The retaining member 104 exerts a compressive force on the damper 106 . The compressive force on the damper 106 may be adjusted by rotating the retaining member 104 on the post 114 . By tightening the retaining member 104 onto the post 114 , the compressive force exerted on the damper 106 is increased. The compressive force may act to expand the damper 106 radially from the post 114 . As the damper 106 expands, the effects of the damper 106 on the motion of the spyder 108 is increased. Thus, by tightening the retaining member 104 , the range of motion of the spyder 108 and the lampshade 112 may be controlled. Additionally, the amount of force necessary to pivot the spyder 108 increases with the tightening of the retaining member 104 .
The retaining member 104 includes a flange portion 107 . The flange portion 107 increases the range of motion of the spyder 108 . The flange portion 108 effectively reduces the diameter of the retaining member 104 in the cavity of the spyder 108 allowing greater clearance when the spyder 108 pivots.
The illustrated exemplary embodiment, the lampshade 112 includes a weight 118 that may be adjusted by a user to ensure that the lampshade 112 is balanced. Preferably, the balanced lampshade will return to a position level with a table or floor following a bump from a user. The weight 118 may be magnetic so that it attaches magnetically to the lampshade 112 . Alternatively, the weight 118 may be secured to the lampshade 112 with an adhesive, or another securing means such as Velcro. In another exemplary embodiment, the lampshade 112 may be balanced in or after production to ensure that the lampshade 112 returns to a level position.
The lampshade leveling system 100 also has the advantage of allowing the lampshade 112 to be level even if the harp 116 or other components of a lamp are misaligned, misformed, or deformed.
FIG. 2 a illustrates a side partially cutaway view of an alternate exemplary embodiment of a lampshade leveling system. In the illustrated embodiment, lampshade leveling system 200 includes a spyder 208 that has a shaped interior surface 209 . In this embodiment, the shaped interior surface 209 is curved such that it has a profile that engages the pivot member 210 . This embodiment is but one example of the shaped interior surface 209 . The shaped interior surface 209 may be, but is not limited to a beveled shape, or another curved shape that facilitates the pivoting of the lampshade 212 . The reduced profile of spyder 208 may allow for a finial 202 to act as a retaining member. FIG. 2 b illustrates a side partially cutaway view of an alternate exemplary embodiment of a lampshade leveling system 200 where the lampshade 212 is angled.
FIG. 3 a illustrates a side partially cutaway view of an alternate exemplary embodiment of a lampshade leveling system. In the illustrated embodiment, lampshade leveling system 300 includes a retaining member 304 having an incorporated finial portion 302 , and a lamp 350 connected to a harp 316 . The incorporated finial portion 302 allows a simplified design without using a threaded portion to attach a separate finial 102 (as shown in FIG. 1 a ). FIG. 3 b illustrates a side partially cutaway view of an alternate exemplary embodiment of a lampshade leveling system 300 where the lampshade 312 is angled.
FIG. 4 illustrates an alternate partially cutaway view of an exemplary embodiment of a lampshade leveling system. In the illustrated embodiment, lampshade leveling system 400 includes a pivot member 410 that is attached to a harp 416 . A threaded post 414 is connected to the pivot member 410 . The lampshade leveling system 400 reduces the number of separate components used in assembling the system 400 , and operates in a similar manner as the embodiments described above.
FIGS. 5 a and 5 b include a partially cutaway view of an alternate exemplary embodiment of a lampshade leveling system. In the illustrated embodiment, lampshade leveling system 500 includes a spyder 508 having a reduced vertical profile. The vertical profile of the spyder 508 is reduced by incorporating a cavity 510 in the upper surface of the spyder 508 .
While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims that follow. These claims should be construed to maintain the proper protection for the invention first described.
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A system for leveling a lampshade comprising, a pivot member operative to engage a post of a lamp harp and support a spyder portion of a lampshade, and a retaining member operative to engage the post and induce a force on the spyder portion.
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REFERENCE TO PRIORITY APPLICATION
This application claims priority to Korean Application Serial No. 2004-49820, filed Jun. 29, 2004, the disclosure of which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to non-volatile memory devices and methods of forming non-volatile memory devices and, more particularly, to memory devices having phase-changeable materials therein and methods of forming same.
BACKGROUND OF THE INVENTION
Conventional phase-changeable random access memories (PRAMs) may utilize a metal-oxide semiconductor (MOS) field effect transistor to control switching within a PRAM cell having a phase-changeable memory element therein. A phase-changeable memory element may utilize a phase-changeable material such as germanium-antimony-tellurium (GST), which is susceptible to phase changes in response to Joule heating. These phase changes enable the material to operate as a non-volatile storage medium for binary data. However, the use of a MOS field effect transistor within each PRAM cell may result in an unnecessarily large layout footprint for each cell and thereby reduce integration density of large PRAM arrays. The use of a MOS field effect transistor may also increase fabrication costs.
One example of a non-volatile phase changeable storage device is illustrated in U.S. Pat. No. 6,750,469 to Ichihara et al. Another non-volatile storage device is illustrated in U.S. Patent Publication No. 2003/0193053 to Gilton. This storage device may include a diode and a memory cell having chalcogenide glass therein. This chalcogenide glass may be formed as a germanium selenide layer.
SUMMARY OF THE INVENTION
Phase-changeable memory devices according to some embodiments of the invention include non-volatile memory cells. Each of these non-volatile memory cells may include a phase-changeable diode on a semiconductor substrate and a phase-changeable memory element having a first terminal electrically coupled to a terminal of the phase-changeable diode. This phase-changeable diode may include a lower electrode pattern on the semiconductor substrate, a first phase-changeable pattern on the lower electrode pattern and a gate switching layer pattern on the first phase-changeable pattern. The phase-changeable memory element includes a second phase-changeable pattern electrically coupled to the terminal of the phase-changeable diode and a memory switching layer pattern on the second phase-changeable pattern. The memory switching layer pattern may include a composite of a titanium layer pattern contacting the phase-changeable memory element and a titanium nitride layer pattern contacting the titanium layer pattern. The first phase-changeable pattern may be a material selected from the group consisting of Ge x As y Te z and Al x As y Te z and the second phase-changeable pattern may be a material selected from the group consisting of Ge x Sb y Te z .
Still further embodiments of the invention include methods of forming non-volatile memory devices and cells having phase-changeable diode and phase-changeable memory elements therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layout view of a phase-changeable random access memory (PRAM) cell according to embodiments of the invention.
FIG. 2 is a cross-sectional view of the PRAM cell of FIG. 1 , taken along line 2 – 2 ′.
FIGS. 3–14 are cross-sectional views of intermediate structures that illustrate methods forming the PRAM cell of FIGS. 1–2 , according to embodiments of the present invention.
FIG. 15 is a current versus voltage graph illustrating characteristics of phase-changeable materials according to embodiments of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Like numbers refer to like elements throughout.
FIG. 1 is a layout view of a PRAM according to an embodiment of the invention, and FIG. 2 is a sectional view of a PRAM taken along line 2 – 2 ′ of FIG. 1 . Referring now to FIGS. 1 and 2 , a device isolation layer 20 is disposed in a semiconductor substrate 10 , while isolating at least one semiconductor active region 25 . A lower electrode layer pattern 32 is disposed on the active region 25 of the semiconductor substrate 10 . The lower electrode layer pattern 32 is disposed to traverse the active region 25 . A pad layer pattern 45 is disposed on the semiconductor substrate 10 . The pad layer pattern 45 may surround the lower electrode layer pattern 32 . The pad layer pattern 45 can be disposed to contact sidewalls of the lower electrode layer pattern 32 . The pad layer pattern 45 may be an electrically insulating layer having an etching ratio different from that of the device isolation layer 20 . Alternatively, the pad layer pattern 45 may be an insulating layer having the same etching ratio as that of the device isolation layer 20 . The pad layer pattern 45 may be a TEOS (tetra-ethyl-orthosilicate), or a HDP (high density plasma) oxide layer. The lower electrode layer pattern 32 may be formed as a titanium nitride (TiN) pattern. Alternatively, the lower electrode layer pattern 32 may be a tungsten (W) pattern.
A gate switching pattern 63 is disposed on the lower electrode layer pattern 32 . The gate switching pattern 63 may include a gate phase-change layer pattern 54 and a gate switching layer pattern 62 , which are sequentially stacked. The gate switching layer pattern 62 is preferably a titanium nitride (TiN) pattern. The gate phase-change layer pattern 54 can be a composite of germanium, arsenic and tellurium (Ge x As y Te z ). Or, the gate phase-change layer pattern 54 can be a composite of aluminum, arsenic and tellurium (Al x As y Te z ). The lower electrode layer pattern 32 has a greater width than that of the gate switching pattern 63 , and is in contact with the main surface of the semiconductor substrate 10 . Alternatively, a gate interlayer insulating layer (not shown) may be interposed between the lower electrode layer pattern 32 and the semiconductor substrate 10 . In this case, the lower electrode layer pattern 32 has a greater width than that of the gate switching pattern 63 , and is in contact with the gate interlayer insulating layer.
A buried interlayer insulating layer 70 is formed on the pad layer pattern 45 and the lower electrode layer pattern 32 , while covering the gate switching pattern 63 . A memory switching pattern 93 is disposed on the buried interlayer insulating layer 70 . The memory switching pattern 93 preferably includes a memory phase-change layer pattern 84 and a memory switching layer pattern 92 , which are sequentially stacked. A gate landing pad 78 is disposed in the buried interlayer insulating layer 70 , to electrically connect the memory switching pattern 93 and the gate switching pattern 63 . The gate landing pad 78 may be preferably a titanium nitride (TiN) layer. The memory switching layer pattern 92 preferably includes a titanium (Ti) pattern and a titanium nitride (TiN) pattern, which are sequentially stacked. The memory phase-change layer pattern 84 is preferably a composite of germanium, antimony and tellurium (Ge x Sb y Te z ). The buried interlayer insulating layer 70 is preferably an electrically insulating layer having an etching ratio different from that of the pad layer pattern 45 . Alternatively, the buried interlayer insulating layer 70 may be an insulating layer having the same etching ratio as that of the pad layer pattern 45 . The buried interlayer insulating layer 70 may be a PEOX (plasma-enhanced oxide) layer.
A planarized interlayer insulating layer 100 is disposed on the buried interlayer insulating layer 70 , while covering the memory switching pattern 93 . An upper electrode layer pattern 110 is disposed on the planarized interlayer insulating layer 100 . The upper electrode layer pattern 110 is disposed perpendicular to the lower electrode layer pattern 32 . A memory landing pad 108 is disposed in the planarized interlayer insulating layer 100 , while being in contact with the upper electrode layer pattern 110 and the memory switching pattern 93 concurrently. The memory landing pad 108 preferably includes a titanium nitride (TiN) layer and a tungsten (W) layer, which are sequentially stacked. The upper electrode layer pattern 110 is preferably an aluminum (Al) layer or a copper (Cu) layer, for example. The planarized interlayer insulating layer 100 is preferably an insulating layer having the same etching ratio as that of the buried interlayer insulating layer 70 . Or, the planarized interlayer insulating layer 100 may be an insulating layer having an etching ratio different from that of the buried interlayer insulating layer 70 . The planarized interlayer insulating layer 100 may be a TEOS layer or a USG (undoped silicate glass) layer.
Now, hereinafter, a method of forming a PRAM having a gate phase-change layer pattern according to the invention will be described as follows. FIGS. 3 through 14 are sectional views illustrating a method of forming a PRAM taken along line I–I′ of FIG. 1 , respectively. Referring to FIG. 1 and FIGS. 3 through 5 , a device isolation layer 20 is formed in a semiconductor substrate 10 . The device isolation layer 20 is formed to isolate at least one active region 25 . A lower electrode layer 30 is formed on the semiconductor substrate having the device isolation layer 20 therein. The lower electrode layer 30 is preferably formed by using a titanium nitride (TiN) layer. The lower electrode layer 30 may also be formed as a tungsten (W) layer.
Then, a photoresist pattern 34 is formed on the lower electrode layer 30 . The photoresist pattern 34 is formed on the active region 25 of the semiconductor substrate 10 . By using the photoresist pattern 34 as an etching mask, an etching process 38 can be performed on the lower electrode layer 30 . The etching process 38 forms a lower electrode layer pattern 32 on the active region 25 of the semiconductor substrate 10 . The lower electrode layer pattern 32 is formed to traverse the active region 25 .
A pad layer 40 is formed to cover the lower electrode layer pattern 32 . The pad layer 40 is preferably formed by using an electrically insulating layer having the same etching ratio as that of the device isolation layer 20 . Or, the pad layer 40 may be formed by using an insulating layer having an etching ratio different from that of the device isolation layer 20 . The pad layer 40 may be formed by using a TEOS (tetra-ethyl-orghosilicate) or a HDP (high density plasma) process.
Referring to FIG. 1 and FIGS. 6 through 8 , By using the lower electrode layer pattern 32 as an etching buffer layer, a planarization process (not shown) is performed on the pad layer 40 . The planarization process is performed until the upper surface of the lower electrode layer pattern 32 is exposed, thereby forming a pad layer pattern 45 . The planarization process can be performed by using CMP (chemical mechanical polishing) or an etching-back technique.
A gate phase-change layer 50 and a gate switching layer 60 are sequentially formed on the semiconductor substrate having the pad layer pattern 45 . The gate switching layer 60 is formed as a titanium nitride (TiN) layer. The gate phase-change layer 50 is preferably formed using a composite of germanium, arsenic and tellurium (Ge x As y Te z ). Alternatively, the gate phase-change layer 50 may be formed using a composite of aluminum, arsenic and tellurium (Al x As y Te z ).
Then, a photoresist pattern 64 is formed on the gate switching layer 60 . The photoresist pattern 64 is formed to be disposed above the lower electrode layer pattern 32 . By using the photoresist pattern 64 as an etching mask, an etching process 68 is sequentially performed on the gate switching layer 60 and the gate phase-change layer 50 . The etching process 68 forms a gate switching pattern 63 on a predetermined region of the lower electrode layer pattern 32 . The gate switching pattern 63 is preferably formed using a gate phase-change layer pattern 54 and a gate switching layer pattern 62 , which are sequentially stacked. The gate switching pattern 63 can secure a switching characteristic of a diode by using a phase-change of the gate phase-change layer pattern 54 . Therefore, the gate switching pattern 63 can replace a CMOS transistor. Further, the gate switching pattern 63 can simplify semiconductor fabrication processes of a PRAM.
A buried interlayer insulating layer 70 is formed to cover the gate switching pattern 63 . The buried interlayer insulating layer 70 is preferably formed using an insulating layer having an etching ratio different from that of the pad layer 40 . The buried interlayer insulating layer 70 may be formed by using an insulating layer having the same etching ratio as that of the pad layer 40 . The buried interlayer insulating layer 70 may be formed using a PEOX (plasma-enhanced oxide) process.
Referring to FIG. 1 and FIGS. 9 and 10 , a gate switching contact hole 74 is formed in the buried interlayer insulating layer 70 . The gate switching contact hole 74 is formed to expose the gate switching pattern 63 . A gate landing pad 78 is formed to fill the gate switching contact hole 74 . The gate landing pad 78 is preferably formed as a titanium nitride (TiN) pad.
Then, a memory phase-change layer 80 and a memory switching layer 90 are sequentially formed on the buried interlayer insulating layer 70 . The memory switching layer 90 is preferably formed as a composite of a titanium (Ti) layer and a titanium nitride (TiN) layer, which are sequentially stacked. The memory phase-change layer 80 is preferably formed using a composite of germanium, antimony and tellurium (Ge x Sb y Te z ).
Referring to FIG. 1 and FIGS. 11 through 14 , a photoresist pattern 94 is formed on the memory switching layer 90 . The photoresist pattern 94 is preferably formed to overlap the gate switching pattern 63 above the semiconductor substrate 10 . By using the photoresist pattern 94 as an etching mask, an etching process 98 is sequentially performed on the memory switching layer 90 and the memory phase-change layer 80 . The etching process 98 forms a memory switching pattern 93 on the buried interlayer insulating layer 70 , being in contact with the gate landing pad 78 . The memory switching pattern 93 is preferably formed using a memory phase-change layer pattern 84 and a memory switching layer pattern 92 , which are sequentially stacked.
A planarized interlayer insulating layer 100 is formed to cover the memory switching pattern 93 . A memory switching contact hole 104 is formed in the planarized interlayer insulating layer 100 . The memory switching contact hole 104 is formed to expose the memory switching pattern 93 . A memory landing pad 108 is formed to fill the memory switching contact hole 104 . The memory landing pad 108 is preferably formed by using a titanium nitride (TiN) layer and a tungsten (W) layer, which are sequentially stacked. The planarized interlayer insulating layer 100 is preferably formed by using an insulating layer having an etching ratio different from that of the buried interlayer insulating layer 70 . Or, the planarized interlayer insulating layer 100 may be formed by using an insulating layer having the same etching ratio as that of the buried interlayer insulating layer 70 . The planarized interlayer insulating layer 100 may be formed by using a TEOS or a USG (undoped silicate glass) process.
An upper electrode layer pattern 110 is formed on the planarized interlayer insulating layer 100 . The upper electrode layer pattern 110 is in contact with the memory landing pad 108 . The upper electrode layer pattern 110 is formed to be disposed perpendicular to the lower electrode layer pattern 32 . The upper electrode layer pattern 110 is preferably formed by using an aluminum (Al) or a copper (Cu).
FIG. 15 is a graph illustrating an operation of a PRAM of FIG. 1 . Referring to FIG. 1 and FIGS. 14 and 15 , in the case that the gate switching pattern 63 and the memory switching pattern 93 are not connected to each other and are used independently, electrical characteristics of the gate switching pattern 63 and the memory switching pattern 93 are shown as follows. First, there will be examined a current characteristic of the memory switching pattern 93 by using a current-voltage graph. In the current-voltage graph, a voltage is applied to the memory switching pattern 93 . The memory switching pattern 93 shows an amorphous state having a high resistance depicted as a current trajectory line 143 until reaching a specific voltage V 1 in the graph. Then, the memory switching pattern 93 causes the memory phase-change layer pattern 84 to make a phase change from an amorphous state to a crystalline state by using Joule heat of current at the specific voltage V 1 . The memory switching pattern 93 shows different current trajectory lines 146 , 149 in the graph because of a decrease of inner resistance through the phase change of the memory phase-change layer pattern 84 . Current trajectory lines 146 shows a change of currents upward to a lower limit value I 1 of a setting region 130 with the start of the phase change of the memory phase-change layer pattern 84 . The current trajectory line 149 vertically traverses the resetting and setting regions 120 , 130 with nearly little change of current above the lower limit value I 1 of the setting region 130 , which is because the phase change of the memory phase-change layer pattern 84 is completed, thereby showing an electrical characteristic of a conductor. The resetting region 120 has a lower limit value I 2 and an upper limit value I 3 of current enough to write data ‘1’ in the memory switching pattern 93 . The setting region 130 has a lower limit value I 1 and an upper limit value I 2 of current enough to write data ‘0’ in the memory switching pattern 93 . Further, the memory switching pattern 93 does not show the electrical characteristics following along the current trajectory lines 143 , 146 , 149 after the phase change of the memory phase-change layer pattern 84 . Instead, under the lower limit value I 1 of the setting region 130 , the memory switching pattern 93 shows another different current trajectory line 140 . While the memory phase-change layer pattern 84 maintains its crystalline state, the memory switching pattern 93 has the electrical characteristic following along the two current trajectory lines 140 , 149 .
Next, there will be examined a current characteristic of the gate switching pattern 63 by using the current-voltage graph. In the current-voltage graph, a voltage is applied to the gate switching pattern 63 . The gate switching pattern 63 shows an amorphous state having a high resistance depicted as a current trajectory line 150 until reaching a specific voltage V 2 in the graph. Then, the gate switching pattern 63 causes the gate phase-change layer pattern 54 to make a phase change from an amorphous state to a crystalline state by using Joule heat of current at the specific voltage V 2 . Since the gate switching pattern 63 and the memory switching pattern 93 use different phase-change layers, respectively, a voltage value causing the gate phase-change layer pattern 54 to start its phase change is also different from the case of the memory switching pattern 93 . The gate switching pattern 63 shows different current trajectory lines 154 , 158 in the graph because of a decrease of inner resistances through the phase change of the gate phase-change layer pattern 54 . The current trajectory line 154 shows a change of current upward to a lower limit value I 1 of a setting region 130 with the start of the phase change of the gate phase-change layer pattern 54 . The other current trajectory line 158 vertically traverses the resetting and setting regions 120 , 130 with nearly little change of currents above the lower limit value I 1 of the setting region 130 , which is because the phase change of the gate phase-change layer pattern 54 is completed, thereby showing an electrical characteristic of a conductor. Further, the gate switching pattern 63 shows the electrical characteristic following along the current trajectory lines 150 , 154 , 158 after the phase change of the gate phase-change layer pattern 54 , according to the reduction of the voltage.
In the event that the gate switching pattern 63 and the memory switching pattern 93 are electrically connected together to form the PRAM, the PRAM shows two different electrical characteristics depending on the crystalline state of the memory phase-change layer pattern 84 . When the gate and the memory phase-change layer patterns 54 , 84 are in an amorphous and a crystalline states, respectively, the PRAM shows a current trajectory line 160 reaching the lower limit value I 1 of the setting region 130 as depicted in the graph. As such, the voltage applied through the upper electrode layer pattern 110 is focused to cause the Joule heat for phase change in the gate phase-change layer pattern 54 . At this time, the PRAM can cause the gate phase-change layer pattern 54 to make the phase change from V 3 . On the contrary, above the lower limit value I 1 of the setting region 130 , the PRAM shows another different current trajectory line 165 passing nearly vertically through the resetting and the setting regions 120 , 130 . This is because the gate and the memory phase-change layer patterns 54 , 84 are completely phase-changed to a crystalline state.
In the event the gate and the memory phase-change layer patterns 54 , 84 are in an amorphous state, the PRAM shows a current trajectory line 170 in the graph showing that a voltage applied through the upper electrode layer pattern 110 is spread to the gate and the memory phase-change layer patterns 54 , 84 , and is focused to cause Joule heat. The PRAM starts to change phases of the gate and the memory phase-change layer patterns 54 , 84 to a crystalline state at a specific voltage V 4 . The phase-change reduces the inner resistance of the gate and the memory phase-change layer patterns 54 , 84 . Therefore, the PRAM shows a current trajectory line 174 reaching from the specific voltage V 4 to the lower limit value I 1 of the setting region 130 in the graph. When the current trajectory line 174 reaches the lower limit value I 1 of the setting region 130 , the gate and the memory phase-change layer patterns 54 , 84 are completely changed to a crystalline state. As such, the PRAM shows a current trajectory line 178 passing nearly vertically through the resetting and the setting regions 120 , 130 .
As described above, embodiments of the invention enable the replacement of a conventional CMOS transistor with a diode based on a phase-change of a gate phase-change layer pattern. Accordingly, embodiments of the invention enable high integration and high speed of a PRAM through the simplification of semiconductor fabrication processes.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
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Phase-changeable memory devices include non-volatile memory cells. Each of these non-volatile memory cells may include a phase-changeable diode on a semiconductor substrate and a phase-changeable memory element having a first terminal electrically coupled to a terminal of the phase-changeable diode. This phase-changeable diode may include a lower electrode pattern on the semiconductor substrate, a first phase-changeable pattern on the lower electrode pattern and a gate switching layer pattern on the first phase-changeable pattern. The phase-changeable memory element includes a second phase-changeable pattern electrically coupled to the terminal of the phase-changeable diode and a memory switching layer pattern on the second phase-changeable pattern. The memory switching layer pattern may include a composite of a titanium layer pattern contacting the phase-changeable memory element and a titanium nitride layer pattern contacting the titanium layer pattern.
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FIELD OF INVENTION
[0001] This present invention relates to an electrical machine being a motor or generator, and more particularly to a synchronous machine having a number of stator pole cores being larger than the number of rotor pole shoes. The present invention further relates to an electrical machine with axial magnetic flux. The electrical machine can operate either as a motor or generator, and will just be called generator in the following.
BACKGROUND OF THE INVENTION
[0002] Electrical generators may be used in many different fields. When a generator is e.g. used in a wind turbine, one of the more important economic parameters, with respect to the dimensioning of the wind turbine, is the size of the housing. It is therefore of great Importance to be able to minimize the diameter of the wind turbine. In order to minimize the housing one has to minimize the gearbox/gear wheel connecting the wing and the generator. This can be achieved by providing a generator which has a relatively large effect per revolution.
[0003] One way to achieve this is to have a generator with as small a radial extent as possible, since the generator occupies a relative large amount of space in the housing of the wind turbine.
[0004] Another aspect to be considered when implementing generators in wind turbines is that the generator has to be effective both at a low and a high number of revolutions.
[0005] An electrical machine based on a conventional radial flux generator, see FIG. 1 , is most frequently used. A main problem with generators of this kind in certain situations is that the diameter for a given power output is relatively large, because of the radially built stator construction. A further disadvantage is that the stator surrounds/encircles the rotor, thereby adding to the diameter of the generator.
[0006] Another disadvantage is the relative low induction in the air gap caused by the individual arrangement of the material between the recess 7 and the recess 2 themselves, since only the material 7 carries the flux and only covers about 50% of the free space toward the gap.
[0007] There are many generators of similar kind, which are optimized in one way or another, but they all have a radial flux and thus involve the same problem, i.e. a relatively larger diameter, like the one described above.
[0008] A motor or generator having an axial flux, see FIG. 2 , is proposed In WO 00/48247, which is hereby included by reference. Here, a motor or generator is provided having a magnetic flux path through one or more pole cores 15 surrounded by current windings 16 and extending in the axial direction. This allows a high density of the magnetic flux to be passed through the pole cores 15 , resulting in a low consumption of material for the pole cores when compared to machines, where for example a large stator diameter may be needed in order to conduct a high magnetic flux. By having the pole cores 15 arranged parallel to the axis of the rotor 10 , the overall diameter of the motor or generator may be reduced, thus providing a solution to some of the above-mentioned problems.
[0009] For the motor or generator described in WO 00/48247 the number of pole cores or pole legs 15 arranged in the stator equals the number of magnets arranged in the rotor, and according to the embodiment illustrated in FIG. 2 , the motor or generator comprises one rotor 10 and one stator. The rotor 10 has a number of pole shoes 13 , disposed between magnets 12 . The stator comprises a number of pole cores or pole legs 15 , where the number of pole legs 15 equals the number of magnets 12 , which again equals the number of pole shoes 13 . There are two adjacent local magnetic circuits for each given pole core 15 . Two of these are schematically illustrated by the first and second loops 18 a , 18 b . It is seen that when the pole shoes 13 are facing the pole legs 15 , a magnetic flux path 18 a includes a first pole leg, a first pole shoe, a magnet, a second pole shoe, and a second pole leg.
[0010] In FIG. 2 , the density of the magnetic flux in the flux path 18 a or 18 b is relatively high, leading to a high resulting axial magnetic force between the rotor 10 and pole legs 15 of the stator. When the stator 10 is rotated so that each magnet 12 is now facing a pole leg 15 , a third magnetic flux path will include only one pole leg 15 , a first pole shoe, a magnet, and a second pole shoe (this situation is illustrated in FIG. 3 ). The magnetic flux density of the third flux path is lower than for the first and the second flux paths 18 a , 18 b , leading to a lower resulting axial magnetic force between the rotor 10 and the pole legs 15 , when compared to the rotor position illustrated in FIG. 2 . So, when the rotor 10 is rotated during use, the resulting axial force between the rotor 10 and the pole legs 15 of the stator will vary between a relatively high and a relatively low force. Such a high, varying axial force may result in several drawbacks including a high wear on the rotor 10 and its axial connection.
[0011] According to another embodiment of the motor or generator described in WO 00/48247 having an axial flux and illustrated in FIG. 3 , the motor or generator comprises one rotor 301 and two stators 302 , 303 arranged on opposite sides of the rotor 301 . The rotor 301 has pole shoes 304 , 305 and a magnet 306 , 307 , 308 between each two succeeding pole shoes. The pole shoes 304 , 305 are crossing the rotor 301 , whereby pole shoes are provided on each side of the rotor 301 . The first stator 302 has pole cores or pole legs 309 , 310 facing the poles shoes 304 , 304 of the rotor 301 , while the second stator 303 has pole cores or pole legs 311 , 312 , 313 facing the magnets 306 , 307 , 308 of the rotor 301 . Here, the pole legs 309 , 310 of the first stator 302 is displaced compared to the position of the pole legs 311 , 312 , 313 of the second stator 303 .
[0012] For the generator of FIG. 3 , a first magnetic flux path 314 of the rotor 301 and the first stator 302 includes the pole legs 310 , 309 , the pole shoe 304 , the magnet 307 , and the pole shoe 305 . However, a second magnetic flux path 315 exists corresponding to the flux path 314 . This second magnetic flux path 315 includes only one pole leg 312 , the pole shoe 304 , the magnet 307 , and the pole shoe 305 . It should be understood that as the number of pole legs in the stators 302 , 303 equals the number of magnets in the rotor 301 , similar corresponding magnetic flux paths exist for the remaining stator pole legs and rotor pole shoes and magnets.
[0013] Here, the density of the magnetic flux in flux path 314 is much higher than the density of the magnetic flux in flux path 315 . Thus, the resulting axial magnetic force between the rotor 301 and the first stator 302 is much higher than the resulting and oppositely directed axial magnetic force between the rotor 301 and the second stator 303 . However, when the rotor 301 is rotated so that the pole shoes 304 , 305 are now facing pole legs 312 , 313 , respectively of the second stator 302 , while the magnet 307 is facing pole leg 310 , the magnitudes of the oppositely directed axial magnetic forces between the rotor 301 and the two stators 302 , 303 changes, so that the force between the rotor 301 and first stator 302 is lower than the force between the rotor 301 and the second stator 302 .
[0014] So, when the rotor 301 is rotating during use, the maximum axial force on the rotor 301 is high, but changes in direction during the rotation. Such a high, varying axial force may result in several drawbacks including a high wear on the rotor 301 and its axial connection.
[0015] Thus, there is a need for a design of a motor or generator having an axial flux, but having only a relatively small variation in the varying axial force on the rotor to thereby reduce the wear of the rotating parts.
SUMMARY OF THE INVENTION
[0016] According to a first aspect of the present invention there is provided an electrical machine comprising:
a rotor secured to a shaft with an axis of rotation, said rotor comprising magnets or means for producing a magnetic field and a number set to N of pole shoes, a first stator with air gaps formed between the rotor and the first stator, said first stator comprising a number set to M of separate pole cores or pole legs having corresponding separate coils or set of windings wound on and surrounding said pole cores or pole legs, wherein N and M are larger than one and M is larger than N.
[0019] It is preferred that the rotor magnets or means for producing a magnetic field are arranged between the pole shoes. According to a preferred embodiment of the present invention, the rotor magnets or means for producing a magnetic field alternate with the pole shoes. Thus, the number N of rotor pole shoes may be equal to the number of magnets or means for producing a magnetic field arranged in the rotor.
[0020] It is preferred that N is an equal number. It is also preferred that M is given by A times N, M=AN, where A is an integral number larger than 1. Thus, it is preferred that M may be equal to 2N, or M may be equal to 3N, or M may be equal to 4N.
[0021] However, the present invention also covers embodiments where M differs from A times N. Here, according to an embodiment of the invention, M may be given by N plus 2 times C, M=N+2C, where C is an integral number larger than or equal to 1.
[0022] According to a preferred embodiment of the present invention, the machine of the invention may further comprise a second stator with air gaps formed between the rotor and the second stator, said second stator comprising a number set to P of separate pole cores having corresponding separate coils or set of windings wound on and surrounding said pole cores, wherein P is larger than one.
[0023] According to an embodiment of the invention, P may be smaller than or equal to N. However, it is preferred that P is larger than N, and P may be given by B times N, where B is an integral number larger than 1. Thus, it is preferred that P may be equal to 2N, or P may be equal to 3N, or P may be equal to 4N. It is also within a preferred embodiment that P is equal to M.
[0024] Also here, the present invention covers embodiments where P differs from B times N, and according to an embodiment of the invention, P may be given by N plus 2 times D, P=N+2D, where D is an integral number larger than or equal to 1.
[0025] It is within a preferred embodiment of the Invention that each separate pole core has a corresponding separate coil or set of windings. It is also within a preferred embodiment that the rotor is arranged so that at least part of the rotor is substantially perpendicular to the axis of rotation
[0026] According to embodiments of the present invention, the pole cores or pole legs may have different orientation in relation to the axis of rotation. However, in a preferred embodiment, at least a portion of one or more of the pole cores or pole legs of the first and/or second stator is arranged at an angle to the axis of rotation, said angle being equal to or greater than 0 degrees and below 90 degrees. Here, the angle between the poles cores or pole legs and the axis of rotation may be equal to or below 45 degrees, such as equal to or below 30 degrees. Preferably, at least a portion of one or more of the pole cores or pole legs may be substantially parallel to the axis of rotation, and it is also within a preferred embodiment that at least a portion of all of the pole cores or pole legs is substantially parallel to the axis of rotation. When at least a portion of one or more of the pole cores or pole legs are substantially parallel to the axis of rotation, then one or more windings or coils may also have their axis substantially parallel to the axis of rotation.
[0027] For the electrical machine of the invention, the first stator may preferably be arranged opposite to and facing a first side of the rotor. For the embodiments of the Invention having two stators, it is preferred that the second stator is arranged opposite to and facing a second side of the rotor.
[0028] When arranging the magnets or means for producing magnetic fields and the pole cores or pole legs, it is preferred that they are arranged so that the pole cores of a stator provide part(s) of one or more magnetic flux paths. Here, a magnetic flux path may include flux paths through two pole cores, and the magnetic flux path may further include two air gaps. Preferably, a magnetic flux path includes two and only two pole cores, and the magnetic flux path may further include two and only two air gaps.
[0029] For the machine of the present invention it is preferred that the rotor is substantially circular. It is also preferred that the first and/or second stator further comprises a magnetic conductive end plate connected to the pole cores, where the end plate(s) may be arranged substantially parallel and opposite to the rotor.
[0030] It is preferred that the magnets or means for producing a magnetic field are arranged in pairs having poles of similar polarity facing each other. When arranging the magnets or means for producing a magnetic field, different arrangement may be used. Thus, the magnets or means for producing a magnetic field may be located radially and equidistantly in the rotor. They may also be located on the first side of the rotor facing ends of the pole cores of the first stator. For embodiments having two stators, magnets or means for producing a magnetic field may be located on the second side of the rotor facing ends of the pole cores of the second stator. However, it is preferred that the magnets or means for producing a magnetic field are located on the outer periphery of the rotor.
[0031] Different outer measures may be used for the pole cores or pole legs arranged in a stator. However, according to an embodiment of the invention it is preferred that the width of a pole core or pole leg is substantially equal to the distance between two successive pole cores or pole legs. It is also preferred that the width of a pole shoe is substantially equal to two times the distance between two successive pole cores or pole legs of the first and/or second stator.
[0032] It should be understood that according to the present invention, the magnets or means for producing a magnetic field may be permanent magnets or electromagnets.
[0033] When producing or forming the windings or coils of the machine of the invention, it is preferred to use a flat concentrated coil. When producing the pole cores, it is preferred that these are made of or assembled of a magnetic conducting material, which magnetic conducting material may be a field oriented soft magnetic lamination.
[0034] The machine according to the embodiments of the present invention may preferably be formed as a synchronous one phase machine. The machine may have the form of a generator, which may be provided with a mechanical force/power via the shaft to generate an electrical power via the windings, or the machine may have the form of a motor, which may be provided with power from an electrical source via the windings to generate a mechanical force/power via the shaft.
[0035] It should be understood that a generator according to an embodiment of the present invention may be well suited to be used in a wind turbine.
[0036] A further object of the present invention is to provide a machine or generator/motor, which may provide a multiple phase output without enlarging the diameter of the generator. The multiple number of phases may be achieved by arranging a corresponding number of one phase machines according to any one of the above mentioned embodiments in series.
[0037] According to a preferred embodiment of the present invention, the pole legs or pole cores may be formed by substantially U-shaped elements. Here, the U-shaped elements may be arranged in the stator so that one pole leg is formed by two adjacent legs of two U-shaped elements. It is preferred that the U-shaped pole legs or pole cores are made of a magnetic conducting material, and that the pole legs are arranged on a stator plate made of a material having a low magnetic conductivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will be explained more fully below in connection with some preferred embodiments and reference to the accompanying drawings, in which:
[0039] FIG. 1 shows a sectional view of a part of a prior art generator having a radial magnetic flux,
[0040] FIG. 2 shows a schematic view of a prior art generator having an axial magnetic flux and having one rotor and one stator,
[0041] FIG. 3 shows a perspective view of a prior art generator having an axial magnetic flux and having one rotor and two stators,
[0042] FIG. 4 shows a sectional view of part of the generator of FIG. 3 ,
[0043] FIGS. 5 a and 5 b show a sectional view of a first embodiment of a generator/motor according to the invention having one rotor and one stator,
[0044] FIG. 6 shows a sectional view of a second embodiment of a generator/motor according to the invention having one rotor and two stators,
[0045] FIG. 7 shows a sectional view of a third embodiment of a generator/motor according to the invention having one rotor and one stator, and
[0046] FIG. 8 shows a sectional view of a fourth embodiment of a generator/motor according to the invention having one rotor and two stators.
DETAILED DESCRIPTION OF THE INVENTION
[0047] FIG. 1 shows a sectional view of a part of a generator according to the prior art. The figure shows a stator 1 which has recesses 2 with coils 3 wound in the traditionally manner, i.e. from a given recess to another, depending on the phases of the current generated. Also shown is a rotor 4 with magnets 5 spaced apart from the boundary of the rotor 4 . Between the magnets 5 on the rotor 4 and the stator 1 there is an air gap.
[0048] When the rotor 4 moves via a shaft (not shown) with respect to the stator 1 , the magnets are moved past the coils 3 and current is thus induced in these.
[0049] If current is supplied to the coils 3 , a magnetic field will make the rotor 4 and the shaft move, and the electrical machine functions as a motor.
[0050] The construction according to the prior art has the disadvantages already mentioned in the Background of the Invention.
[0051] FIG. 2 shows a schematic view of an embodiment of a prior art generator having an axial magnetic flux and described in WO 00/48247. The Figure shows a pole wheel 10 which functions as a rotor and is secured to a shaft 11 . A plurality of magnets 12 is disposed radially in such a way that the magnets have poles of similar polarity (N) facing each other and poles of similar polarity (S) facing each other. The magnets 12 are preferably permanent magnets but could also be electromagnets or the like.
[0052] A plurality of pole shoes 13 , preferably made of laminated sheet metal or massive iron, is disposed between the magnets 12 , which concentrate the magnetic flux and have a relatively small remanence/residual magnetism, i.e. they are good magnetic conductors. The pole shoes 13 and the magnets 12 are magnetically Isolated from the shaft 11 .
[0053] Spaced apart from the rotor 10 , a magnetic termination plate/end shield 17 is provided with a plurality of pole legs/pole cores 15 secured to the plate 17 in such a way that only an air gap 14 exists between the rotor 10 and the pole shoes 13 . The plate 17 and the pole cores 15 function as a stator 15 , 17 . The plate 17 is preferably a circular core using non field orientated laminated iron wrapped in a circular shape using one length of iron.
[0054] The plate 17 functions as a magnetic ‘short circuit’ and conducts the magnetic flux between the relevant pole cores 15 in a given magnetic circuit. Thus, in this embodiment, a closed local magnetic circuit consists of: a magnet 12 , a pole shoe 13 , an air gap 14 (which amplifies the flux), a pole core 15 , the magnetic termination plate 17 , an adjacent pole core, a neighbour air gap, a neighbour pole shoe.
[0055] There are two adjacent local magnetic circuits for each given pole core 15 . Two of these are schematically illustrated by the loops 18 a , 18 b , and have already been discussed in the background of the invention.
[0056] Electrical windings 16 , e.g. coils, preferably surround each of the pole legs 15 . Preferably, the coils 16 are tightly and closely wound around the pole legs 15 . This arrangement is very efficient with respect to induction in the windings/coils 16 , since the flux is highly concentrated/uniform in the pole cores 15 in this arrangement. The windings 16 are preferably formed by flat concentrated coil, which has a high fill factor. By having the windings 16 concentrated on the pole cores 15 almost all of the coil material is affected, as opposed to the generator shown in FIG. 1 , since the flux flow affects almost all of the coil material (except of course the material conducting the current away from the generator).
[0057] When the rotor 10 is moved with respect to the stator 15 , 17 , the magnetic flux in a given pole core 15 changes direction, since the polarity at the air gap 14 changes (from N to S or vice versa), and current is thereby induced in the windings 16 . This induction is very efficient, as mentioned, since the magnetic flux is highly concentrated/uniform in the area surrounded by windings 16 , i.e. in the pole core 15 .
[0058] For stand-alone generators the shaft 11 is preferably rotatably mounted in a bearing or the like (not shown) in the plate 17 to support the shaft 11 additionally and stabilize the rotation of the rotor 10 with respect to the stator 15 , 17 . For generators used in wind turbines, the rotor 10 is preferably secured on the shaft of the wind turbines and the stator 15 , 17 is preferably secured to a bearing holding the shaft of the wind turbines.
[0059] In FIG. 2 the magnets 12 are arranged radially, but as an alternative, they may be arranged on the side of the rotor 10 in such a way that the magnets have poles of similar polarity (N) facing each other and poles of similar polarity (S) facing each other, and in such a way that the magnets 12 are facing the pole legs 15 . Also here, pole shoes 13 may be disposed between the magnets 12 .
[0060] FIG. 3 shows a perspective view of a prior art motor/generator corresponding to another embodiment of a motor/generator described in WO 00/48247 having an axial magnetic flux and having one rotor and two stators. The motor/generator comprises one rotor 301 and two stators 302 , 303 arranged on opposite sides of the rotor 301 . The rotor 301 has pole shoes 304 , 305 and a magnet 306 , 307 , 308 between each two succeeding pole shoes. The pole shoes 304 , 305 are crossing the rotor 301 , whereby pole shoes are provided on each side of the rotor 301 .
[0061] The first stator 302 has pole cores or pole legs 309 , 310 facing the poles shoes 304 , 305 of the rotor 301 , while the second stator 303 has pole cores or pole legs 311 , 312 , 313 facing the magnets 306 , 307 , 308 of the rotor 301 . Here, the pole legs 309 , 310 of the first stator 302 is displaced compared to the position of the pole legs 311 , 312 , 313 of the second stator 303 . The pole cores 309 , 310 of the first stator 302 are secured to a first magnetic termination plate/end shield, while the pole cores 311 , 312 , 313 of the second stator 303 are secured to a second magnetic termination plate/end shield. Each of the termination plates is preferably a circular core using non field orientated laminated iron wrapped in a circular shape using one length of iron.
[0062] Similar to the pole legs 15 of FIG. 2 , then for the pole legs 309 , 310 of the first stator and 311 , 312 , 313 of the second stator, electrical windings (not shown), e.g. coils, surround each of the pole legs. Preferably, the coils are tightly and closely wound around the pole legs.
[0063] The magnetic flux paths 314 , 315 of the motor/generator of FIG. 3 have already been discussed in the Background of the Invention.
[0064] It should be understood that the materials used for the motor/generator of FIG. 3 may correspond to the materials used for the motor/generator of FIG. 2 .
[0065] In FIG. 4 is shown a sectional view of part of the motor/generator of FIG. 3 , and the reference numbers are the same as for FIG. 3 . FIG. 4 gives a more detailed view of the arrangement of the poles legs 309 - 313 of the two stators 302 , 303 in relation to the pole shoes 304 , 305 and the magnets 306 , 307 , 308 of the rotor 301 . It is also seen how the first magnetic flux path 314 includes the pole legs 309 , 310 , the pole shoe 304 , the magnet 307 , and the pole shoe 305 , while the second magnetic flux path 315 includes the pole leg 312 , the pole shoe 304 , the magnet 307 , and the pole shoe 305 . As the pole leg 312 is not facing any of the poles shoes 304 or 305 , the magnetic flux density of flux path 315 is much lower than for the flux path 314 .
[0066] However, according to the present invention, the resulting high, varying axial force of the prior art motor/generators discussed above may be reduced by having a stator with a larger number of pole cores than magnets or pole shoes arranged in the rotor. This is illustrated in the followings figures, in which FIG. 5 shows a sectional view of a first embodiment of a generator/motor according to the invention having one rotor 501 and one stator 502 .
[0067] The motor/generator of FIG. 5 corresponds to the design of the motor/generator of FIG. 2 and may have the same outer dimensions. The motor/generator of FIG. 5 has a rotor 501 with pole shoes 503 and a magnet 504 between each two succeeding pole shoes 503 . So, the number of magnets 504 is equal to the number of pole shoes 503 , which number is set equal to N. The stator 502 comprises a number M of pole cores or pole legs 505 , with each pole core or pole leg 505 having a corresponding coil 506 , but in contrast to the motor/generator of FIG. 2 , M is two times N, whereby the number of pole cores or legs 505 is two times the number of pole shoes 503 or magnets 504 arranged in the rotor 501 . The pole cores 505 of the stator are secured to a magnetic termination plate/end shield 507 and the rotor 501 may be secured to a shaft (not shown). It is preferred that the pole shoes 503 and the magnets 504 are magnetically isolated from the shaft. It is also preferred that the magnets 504 are permanent magnets.
[0068] In a preferred embodiment, the materials used for motor/generator of FIG. 5 correspond to the materials used for the motor/generator of FIG. 2 . However, for the motor/generator of FIG. 5 it is preferred that the width of a pole shoe 503 is substantially equal to the width of a magnet 504 , and the width of a stator pole core or leg 505 may be only half the width of a rotor pole shoe 503 or a rotor magnet 504 .
[0069] In FIG. 5 a , the rotor 501 is in a position so that each pole shoe 503 and each magnet are directly facing a pole leg 505 . A magnetic flux path 508 is shown, and it is seen that the path 508 includes a first pole leg 505 a , a first pole shoe 503 a , a magnet 504 a , a second pole shoe 503 b , and a second pole leg 505 b . It is also seen that a third pole leg 505 c in between the first and second pole legs 505 a,b is not part of the magnetic flux path 508 .
[0070] When comparing the magnetic flux path 508 of FIG. 5 a to the magnetic flux path 18 a of FIG. 2 , the total area of the two pole legs 505 a , 505 b facing the rotor 502 is smaller than the total area of the two pole legs 15 in FIG. 2 facing the rotor 10 and being part of the magnetic flux path 18 a . Thus, the total magnetic flux in the flux path 508 is smaller than the total magnetic flux running in flux path 18 a , with the result that the maximum resulting axial force between the rotor 501 and the stator 502 in FIG. 5 a is smaller than the maximum resulting axial force between the rotor 10 and the stator in FIG. 2 .
[0071] However, when the machine of FIG. 5 is a generator then, due to the lower magnetic flux in the pole legs 505 a , 505 b , the generated electrical output of the coils 506 a , 506 b is smaller than the output generated from the coils 16 surrounding the pole legs of the flux path 18 a in FIG. 2 . This may be compensated for by having a higher number of wirings in the coils 506 a , 506 b when compared to the wirings of the coils 16 in FIG. 2 . As the circumference of a pole leg 505 in FIG. 5 is smaller than the circumference of a pole leg 15 in FIG. 2 , then for the same consumption of coil material (such as copper), a larger number of wirings may be achieved for the coils 506 in FIG. 5 than for the coils 16 in FIG. 2 .
[0072] In FIG. 5 b , the rotor 501 has been rotated when compared to FIG. 5 a and is in a position so that each pole leg 505 is directly facing a passage between a pole shoe 503 and a magnet 504 . A magnetic flux path 509 is shown, and it is seen that it includes a pole leg 505 d , a pole shoe 503 c , a magnet 504 b , another pole shoe 503 d , and another pole leg 505 e . It is also seen that in this position it is two neighbouring pole legs 505 d , 505 e , which are now part of the flux path 509 . It is furthermore seen that when neglecting the effects of leakage or stray flux, the magnetic flux path 508 uses half of the pole legs 505 a and 505 b , and the magnetic flux path 509 uses half of the pole legs 505 d and 505 e . Thus, the total magnetic flux running in the flux path 509 of FIG. 5 b is substantially equal to the magnetic flux running in the flux path 508 of FIG. 5 a.
[0073] In FIG. 5 a there are two flux paths running through the pole legs 505 a and 505 b , but there are no flux paths using the pole leg 505 c . Thus, half of the pole legs in FIG. 5 a are filled up by two flux paths, while the other half of the pole legs have no flux path. In FIG. 5 b a flux path is running through every pole leg, but only half of each pole leg is occupied by a flux path. So, the total magnetic flux between the stator 502 and the rotor 501 in FIG. 5 a is substantially equal to the total magnetic flux between the stator 502 and the rotor 501 in FIG. 5 b . Thus, the change in the resulting axial force when rotating the rotor 501 of the motor/generator of FIG. 5 will be very small and much smaller than the change in the resulting axial force of the motor/generator of FIG. 2 .
[0074] FIG. 6 shows a sectional view of a second embodiment of a generator/motor according to the invention having one rotor 601 and two stators 602 a , 602 b.
[0075] The motor/generator of FIG. 6 corresponds to the design of the motor/generator of FIG. 3 and may have the same outer dimensions. The motor/generator of FIG. 6 has a rotor 601 with pole shoes 603 and a magnet 604 between each two succeeding pole shoes 603 . So, the number of magnets 604 is equal to the number of pole shoes 603 , which number is set equal to N. Both the first stator 602 a and the second stator 602 b comprises a number M of pole cores or pole legs 605 a , 605 b , with each pole core or pole leg 605 a , 605 b having a corresponding coil 606 a , 606 b , but in contrast to the motor/generator of FIG. 3 , M is two times N, whereby the number of pole cores or legs 605 a and 605 b is two times the number of pole shoes 603 or magnets 604 arranged in the rotor 601 . Also here, the pole cores 605 a and 605 b of the stators 602 a and 602 b are secured to corresponding magnetic termination plates/end shields 607 a , 607 b and the rotor 601 may be secured to a shaft (not shown). Again, it is preferred that the pole shoes 603 and the magnets 604 are magnetically isolated from the shaft. It is also preferred that the magnets 604 are permanent magnets.
[0076] In a preferred embodiment, the materials used for motor/generator of FIG. 6 correspond to the materials used for the motor/generator of FIG. 3 . However, for the motor/generator of FIG. 6 it is preferred that the width of a pole shoe 603 is substantially equal to the width of a magnet 604 , and the width of a stator pole core or leg 605 may be only half the width of a rotor pole shoe 603 or a rotor magnet 604 .
[0077] In FIG. 6 , the rotor 601 is in a position so that each pole shoe 603 and each magnet 604 are directly facing a pole leg 605 a of the first stator 602 a . A magnetic flux path 608 is shown, and it is seen that it includes a first pole leg 605 aa , a first pole shoe 603 a , a magnet 604 a , a second pole shoe 603 b , and a second pole leg 605 ab . It is also seen that a third pole leg 605 ac in between the first and second pole legs is not part of the magnetic flux path 608 . For the pole legs 605 b of the second stator, each pole leg 605 b is directly facing a passage between a pole shoe 503 and a magnet 504 . A magnetic flux path 609 is shown, and it is seen that it includes a pole leg 605 ba , the first pole shoe 603 a , the magnet 604 a , a second pole shoe 603 b , and another pole leg 605 bb.
[0078] For the magnetic flux paths 608 and 609 , the discussion given above in connection with FIGS. 5 a and 5 b is valid, leading to the result that for the shown position of the rotor 601 and the stators 602 a and 602 b , the total magnetic flux between the stator 602 a and the rotor 601 is substantially equal to the total magnetic flux between the stator 602 b and the rotor 601 . So, the resulting axial force between the rotor 601 and the first stator 602 a is smaller than the resulting axial force between the rotor 301 and the first stator 302 of FIG. 3 , while the resulting axial force between the rotor 601 and the second stator 602 b is higher than the resulting axial force between the rotor 301 and the second stator 303 of FIG. 3 .
[0079] Thus, the change in the resulting axial force when rotating the rotor 601 of the motor/generator of FIG. 6 will be very small and much smaller than the change in the resulting axial force of the motor/generator of FIG. 3 .
[0080] The discussion for the number of wires of the coils 506 given above in connection with FIG. 5 is also valid for the coils 606 a and 606 b of FIG. 6 .
[0081] It is also within the present invention to provide a generator in which the number M of stator pole cores is four times the number N of the pole shoes. This is illustrated in FIG. 7 , which shows a sectional view of a third embodiment according to the invention. The motor/generator of FIG. 7 corresponds to the design of the motor/generator of FIG. 5 and may have the same outer dimensions, but in FIG. 7 M is four times N, whereas in FIG. 5 M is two times N. The motor/generator of FIG. 7 has a rotor 701 with pole shoes 703 and a magnet 704 between each two succeeding pole shoes 703 . Also here, the number of magnets 704 is equal to the number of pole shoes 703 , which number is set equal to N. The stator 702 comprises the number M of pole cores or pole legs 705 , with each pole core or pole leg 705 having a corresponding coil 706 . The pole cores 705 of the stator may be secured to a magnetic termination plate/end shield 707 and the rotor 701 may be secured to a shaft (not shown). It is preferred that the pole shoes 703 and the magnets 704 are magnetically isolated from the shaft. It is also preferred that the magnets 704 are permanent magnets.
[0082] In a preferred embodiment, the materials used for the motor/generator of FIG. 7 correspond to the materials used for the motor/generator of FIG. 5 . Thus, for the motor/generator of FIG. 7 it is preferred that the width of a pole shoe 703 is substantially equal to the width of a magnet 704 , and the width of a stator pole core or leg 705 may be only one quarter of the width of a rotor pole shoe 703 or a rotor magnet 704 .
[0083] In FIG. 7 , the rotor 701 is in a position so that each pole shoe 703 and each magnet are directly facing two pole legs 705 . A magnetic flux path 708 is shown, and it is seen that the path 708 includes a first pole leg 705 a , a first pole shoe 703 a , a magnet 704 a , a second pole shoe 703 b , and a second pole leg 705 b . It is also seen that two pole legs in between the first and second pole legs 705 a,b are not part of the magnetic flux path 708 .
[0084] From FIG. 7 it is seen that the flux path 708 fully occupies the pole legs 705 a and 705 b , while the neighbouring pole legs also facing a pole shoe are occupied by another magnetic flux path. For the remaining half of the pole legs, which are facing a magnet, then to a good approximation, no magnetic flux path is running through these pole legs. When comparing the embodiment of FIG. 7 with the embodiment of FIG. 5 a , the total magnetic flux running between the rotor 701 , 501 and the stator 702 , 502 will be the same for the same dimensions and for the same number N of magnets 704 , 504 and pole shoes 703 , 503 .
[0085] When rotating the rotator 701 of FIG. 7 the width of a pole leg 705 in a clockwise direction, then the situation will be the same as shown in FIG. 7 , i.e. for each pole shoe 703 two pole legs 705 will bee facing the pole shoe 703 , and for each magnet 704 two pole legs 705 will be facing the magnet 704 . So, the total pole leg area facing a pole shoe will be the same as illustrated in FIG. 7 with the result that the total magnetic flux running between the stator 702 and the rotor will be substantially the same as in FIG. 7 . Thus, the same discussion may be used as given in connection with FIG. 5 , and the change in the resulting axial force when rotating the rotor 701 of the motor/generator of FIG. 7 will be very small.
[0086] FIG. 8 shows a sectional view of a fourth embodiment according to the invention having one rotor 801 and two stators 802 a and 802 b . The motor/generator of FIG. 8 corresponds to the design of the motor/generator of FIG. 6 and may have the same outer dimensions. The motor/generator of FIG. 8 has a rotor 801 with pole shoes 803 and a magnet 804 between each two succeeding pole shoes 803 . So, the number of magnets 804 is equal to the number of pole shoes 803 , which number is set equal to N. Both the first stator 802 a and the second stator 802 b comprises a number M of pole cores or pole legs 805 a , 805 b , with each pole core or pole leg 805 a , 805 b having a corresponding coil 806 a , 806 b , but in contrast to the motor/generator of FIG. 6 , M is four times N, whereby the number of pole cores or legs 805 a and 805 b is four times the number of pole shoes 803 or magnets 804 arranged in the rotor 801 . Also here, the pole cores 805 a and 805 b of the stators 802 a and 802 b may be secured to corresponding magnetic termination plates/end shields 807 a , 807 b and the rotor 801 may be secured to a shaft (not shown). Again, it is preferred that the pole shoes 803 and the magnets 804 are magnetically isolated from the shaft. It is also preferred that the magnets 804 are permanent magnets.
[0087] In a preferred embodiment, the materials used for motor/generator of FIG. 8 correspond to the materials used for the motor/generator of FIG. 6 . However, for the motor/generator of FIG. 8 it is preferred that the width of a pole shoe 803 is substantially equal to the width of a magnet 804 , and the width of a stator pole core or leg 805 may be only one quarter of the width of a rotor pole shoe 803 or a rotor magnet 804 .
[0088] In FIG. 8 , the rotor 801 is in a position in relation to the stators 802 a and 802 b similar to the position of the stator 701 and the stator 702 of FIG. 7 . So, the rotor 801 is in a position so that each pole shoe 803 and each magnet 804 are directly facing two pole legs 805 a and 805 b of each stator 802 a , 802 b . Two magnetic flux paths 808 and 809 are shown, and It is seen that each path 808 and 809 includes two pole legs, two pole shoes, and one magnet. It is also seen that two pole legs, which are arranged in between two pole legs being part of a flux path 808 , 809 , are not part of a magnetic flux path.
[0089] So, in FIG. 8 the total pole leg area facing a pole shoe will be the same for the pole legs 805 a of stator 802 a as for the pole legs 805 b of the stator 802 b , with the result that the total magnetic flux running between the stator 802 a and the rotor 801 will be substantially the same as for the stator 802 b and the rotor 801 . Thus, the same discussion may be used as given in connection with FIGS. 5-7 , and the change in the resulting axial force when rotating the rotor 801 of the motor/generator of FIG. 8 will be very small.
[0090] In should be understood that for electrical machines of the present invention, the stator may in most cases comprise a relatively large number of separate pole cores or pole legs (for example 40 pole cores) and a corresponding number of separate or discrete coils or set of windings.
[0091] Such as large number of discrete and galvanic separated coils gives the opportunity of forming a very large number of combinations of voltages and currents.
[0092] A few examples:
[0000] all coils of one stator may be arranged in series to produce a high voltage;
all coils of one stator may be arranged in parallel to obtain the same voltage as of one coil, but a higher current;
one, two, three or more coils arranged in parallel may be arranged in series with one, two, three or more coils arranged in parallel, all coils being part of the same stator.
[0093] While the invention has been particularly shown and described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and it is intended that such changes come within the scope of the following claims.
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The present invention relates to an electrical multipole motor/generator or electrical machine with axial magnetic flux, wherein the machine has a number of stator pole cores being larger than the number of rotor pole shoes. Thus, a motor/generator or electrical machine is provided in which the machine comprises a rotor secured to a shaft with an axis of rotation, where the rotor comprises magnets or means for producing a magnetic field and a number set to N of pole shoes. The machine further comprises a first stator with air gaps formed between the rotor and the first stator, where the first stator comprises a number set to M of separate pole cores or pole legs having corresponding separate coils or set of windings wound on and surrounding said pole cores or pole legs, wherein N and M are larger than one and M is larger than N. N may be an equal number, and M may be equal to 2N, or M may be equal to 3N, or M may be equal to 4N. According to an embodiment of the invention, the electrical machine may further comprise a second stator with air gaps formed between the rotor and the second stator, where the second stator comprises a number set to P of separate pole cores having corresponding separate coils or set of windings wound on and surrounding said pole cores, wherein P is larger than one. P may be larger than N, and P may be equal to 2N, or P may be equal to 3N, or P may be equal to 4N. Thus, according to an embodiment of the invention P may be equal to M.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to portable automobile security alarms, and more particularly to a window mounted alarm having a siren mounted externally to the window.
2. Description of the Prior Art
Automobile theft is a pervasive problem. In the past, various types of automobile protection systems have been devised to protect automobiles from theft. Such alarm systems are secured to the automobile frame or chassis and move with the car upon a tampering attempt. Such systems contain motion sensors operative to detect tampering or movement of the automobile to trigger an alarm. The alarms can be acoustic alarms designed to announce intrusions, deter further intrusions, and attract help from passers by. Such systems are generally powered by the car battery.
Automobile alarm systems have been connected with the automobile car horn to generate the acoustic alarm. These systems are permanently installed in the vehicle and require a considerable amount of time and labor thus being far from portable. Such systems require some degree of skill to mount on an automobile and are expensive to manufacture and install. Because such systems are electronically sophisticated they are often prone to malfunction.
New and used cars on sales lots are an open invitation to thieves and vandals. It is impractical to install a permanent alarm system on a car that may only be on the lot for a few days. Thus, portable and detachable alarm systems are useful for businesses with a great turnover of automobiles, such as automobile dealerships. They can be easily removed and replaced as cars are sold. Portable alarms are easily mounted, inexpensive to make and purchase, and give the user the option of utilizing the device on multiple vehicles. Generally, a siren within the alarm unit is used instead of the horn. Because of their portable nature, the capacity of the power source is limited.
Disturbance sensitive portable automobile alarm devices have been designed to hang over the top edge of a side window of an automobile with compartment like structures on both sides. The devices can utilize a motion sensor and an internal power source within the interior compartment and can generate an audible alarm and/or transmit a radio frequency ("RF") signal upon activation. Indicator lights on the device provide an indication of active status. Examples of such devices can be found in U.S. Pat. Nos. 4,155,067 to Gleeson and 4,187,497 to Howell et al. While serving their intended purpose of sounding an alarm such devices suffer the shortcoming that, for instance, the alarm of Gleeson is in two separable and easily disconnectable parts and the alarm of Howell et al. fails to afford propagation of the audible alarm at a sufficiently high intensity to ensure a reasonably adequate range.
The intensity of an automobile alarm is an important component in its ability to provide an effective deterrent. A shortcoming of smaller portable alarms is that they are often not as loud as permanent alarms that utilize the automobile horn. Their power supply and size limit the intensity of range of the alarm annunciator.
SUMMARY OF THE INVENTION
The invention provides a portable window hanging automobile alarm having an electronic housing in juxtaposition with an alarm housing. The respective housings are connected by a flat hanger spring assembly incorporating a pair of sheet spring strips having sandwiched therebetween electrical conductors. A control switch and a port for receipt of an electrical lead leading from a cigarette lighter socket are carried on the electronic housing. The outwardly facing side of such electronic housing mounts one or more cylindrical rubber bumpers to abut the window and cooperate in pressing the alarm housing firmly against the window. The alarm housing is formed on its outwardly facing side with an acoustic transducer and on its rearward side with an exciter cap into which the hub of an acoustic driver nests. The exciter cap is configured in relationship to the respective bumpers so that a user can roll an automobile window partially down and spread the electronic housing and alarm housing apart against the bias of the hanger spring for receipt therebetween of the window. The hanger spring is lowered to rest on the upper edge of the window and the window can be raised to trap the hanger spring between the top edge of the window and the window frame so that the electronic housing is maintained interior of the window and the alarm housing exterior of the window. The electronic housing is pressed against the window so that, in the event the automobile is disturbed causing movement, such movement will be positively communicated to a tamper sensor within the electronic housing. The tamper sensor generates a tamper signal in response to the movement. The tamper signal causes the acoustical driver to initiate audible vibrations from the acoustic transducer. Such vibrations are imparted directly to the surface of the window by the exciter cap initiating corresponding vibration of the window to enhance propagation of the alarm sound.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a window mounted automobile security alarm mounted on an automobile window;
FIG. 2 is an enlarged, perspective view of the window mounted automobile alarm shown in FIG. 1;
FIG. 3 is a transverse sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a schematic representation of electrical circuits and components in the window mounted automobile security alarm shown in FIG. 1;
FIG. 5 is a partial front view, partly in cut-away section, of the automobile alarm shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, for purposes of illustration, the present invention is embodied in a window mounted automobile security alarm. The portable alarm includes an electronic housing connected to an alarm housing by a hanger spring. The alarm is mounted on a side window of an automobile and is responsive to shock and motion to generate an acoustical alarm. The electronic housing is positioned on the inside of the automobile protected from the elements while the metallic alarm housing is on the outside enhancing the loudness of the alarm siren.
In accordance with the present invention, the window mounted automobile security alarm includes an exterior alarm housing mounted in abutment with the side window of the automobile. An acoustic transducer is mounted on the outwardly facing side of the alarm housing. An acoustic driver is mounted in the alarm housing. A tamper detector mounted within the interior electronic housing is electrically coupled to the acoustical driver. The tamper detector is responsive to shock and motion to operate the acoustic driver to drive an acoustical alarm from the acoustic transducer. When in mounted position, the exterior alarm housing is urged toward the interior electronic housing by the bias of the hanger spring assembly. An exciter cap mounted on the rearward side of the alarm housing directly confronts and is held firmly in positive contact with the exterior surface of the window which correspondingly vibrates to enhance propagation of the acoustic alarm.
The portable alarm apparatus 10 of the present invention is mounted over the top edge 12 of a automobile side window on an automobile 14 and is secured between the top edge 12 of the window and the window frame, as shown in FIG. 1. The electronic housing 16 is positioned within the interior of the automobile protected from the elements and away from the hands of vandals, as shown in FIG. 2. The alarm housing 18 is electrically coupled to the electronic housing 16 and is responsive to shock to the electronic housing 16 and motion of the electronic housing carried by the car to propagate an audible annunciator alarm. The housings are colored red for high visibility. A rigid metallic exciter cap 20 (FIG. 3) mated to an exciter aperture of the alarm housing 18 vibrates against the exterior surface 22 of the window in response to propagation of the alarm by the acoustic transducer. This causes the window to vibrate contemporaneously with the exciter cap 20 to reinforce the sound intensity of the alarm apparatus 10.
The alarm housing 18 is molded from a metal alloy and is formed in its outwardly facing wall with a sound grille 24 (FIG. 3) through which the acoustic transducer propogates the alarm sound. An exciter aperture is formed on a rearward side of the alarm housing opposite to the front face of the alarm housing. The exciter cap 20 consisting of a rigid, bulbous metal member is mated through the exciter aperture to the alarm housing and is coupled to the acoustic driver 26 (FIG. 4) within the alarm housing 18. The acoustic transducer 28 (FIG. 4) is in the form of a metallic loudspeaker siren. The siren is weather, freon, and shatter proof. The acoustic driver 26 is responsive to an alarm signal from the electronic housing to generate a driver signal. The loudspeaker is responsive to the driver signal to generate sound waves. The exciter cap 20 (FIG. 3) is biased positively against the surface 22 of the window forcing it to vibrate in unison with the exciter cap when the acoustic driver 26 (FIG. 4) is activated.
The electronic housing 16 (FIG. 3) is formed of an elongated plastic casing. A light emitting diode ("LED") array 32 (FIG. 2) is disposed on the electronic housing and is capable of indicating that the device is armed. A rotary sensitivity control thumb knob 34 is mounted on and extends through a slot in the electronic housing for adjusting the activation level of an internal microphone acting as a sound sensor. A port (not shown) for receipt of an electrical lead from the car cigarette lighter is formed through the plastic housing and connects in parallel with the dry cell batteries to provide for access to an alternative twelve volt power source. A plurality of conical shaped rubber bumpers 36 are equidistantly positioned on the inwardly facing side of the electronic housing 16.
Referring to FIG. 4, a tamper sensor 40 is mounted within an actuation compartment in the electronic housing. The tamper sensor 40 includes both a shock and motion detector. In the preferred embodiment, such detector includes an electrically insulative housing with a plurality of spaced electrical contacts configured to define a recessed nest into which an electrically inductive spherical ball normally rests. Upon shifting of the housing due to movement of the car, the ball will roll from its rest position budging between a pair of adjacent contacts thus actuating the control circuit. The tamper sensor may also include a microphone and band pass filter for detecting the sound frequencies of breaking glass. The tamper sensor generates a tamper signal in response to shock to, tampering with, or motion near the actuation compartment.
Various electrical circuits are employed within the electronic housing to control operation of the portable automobile alarm. An oscillator circuit 42 for generating a characteristic alarm siren waveform is coupled to the tamper sensor. The oscillator circuit is responsive to the tamper signal to generate an oscillator signal. An amplifier circuit 44 is coupled to the oscillator circuit. The amplifier amplifies the oscillator signal to generate an alarm signal that is passed to the acoustic driver 26 in the alarm housing 18.
A control circuit 46 supplies power to the active components and circuitry of the electronic housing from an internal battery supply 48 or an external supply, such as from an automobile cigarette lighter. The control circuit (FIG. 2) includes an on-off switch having a thumb slider 57 (FIG. 3) projecting through a slot in the housing 16.
Referring to FIG. 4, a remote control receiver circuit 50 is coupled to the control circuit 46 and is operative to control the control circuit 46. The remote control transmitter 52 is coupled to the remote control receiver circuit 50 by an RF communications link. The transmitter 52 is operative to generate a transmitter signal which is discernable at distances up to 100 feet from the receiver 50. The receiver circuit 50 is responsive to the transmitter signal to disable the alarm through the control circuit 46.
An LED circuit 54 is coupled to the control circuit 46. The LED circuit illuminates the LED array 32 when the control circuit 46 is supplying power to the active components and circuitry in the electronic housing. The illuminated LED array indicates that the alarm is armed.
The internal battery supply 48 and a power supply circuit 56 are coupled to the control circuit 46. Two nine volt batteries are utilized internally. The power supply circuit 56 is electrically coupled to the electrical port through the electronic housing for receipt of an electrical lead coupled to for instance, the automobile cigarette lighter. The power supply circuit 56 functions as a twelve volt adapter circuit.
Referring to FIG. 3, the hanger spring assembly 58 coupling the electronic housing 16 with the alarm housing 18 is formed from a pair of sturdy and resilient U-shaped sheet metal springs 59 (FIG. 5). The sheet springs a opposite ends to the respective housings. The hanger spring assembly biases the alarm housing toward the electronic housing to sandwich the side window 22 of the automobile firmly between the cylindrical bumpers 36 and the exciter cap 20 so that vibration of such cap is imparted directly to the window.
A plurality of electrical conductors 62 electronically link the two housings, as shown in FIG. 5. The electrical conductors 62 are copper wire encased in plastic sheaths. The conductors 62 are sandwiched between the U-shaped sheet springs 59 of the hanger spring assembly 58, as shown in FIG. 5. The amplifier circuit 44 (FIG. 4) in the electronic housing 16 is operative to pass an alarm signal to the acoustic driver 26 (FIG. 4) in the alarm housing via the electrical conductors.
In operation, the hanger spring assembly 58 (FIG. 2) of the window mounted automobile alarm is mounted over the top edge 12 (FIG. 2) of the window by the user. The window is then raised to secure the alarm to the automobile. With the switch 34 on, the alarm apparatus is armed by operating the remote control transmitter 52 (FIG. 4). Once armed, the LED array 32 (FIG. 2) flashes indicating an active status to the user and warning a potential unauthorized intruder that the device is activated.
Should an unauthorized person jar or shake the electronic housing 16 (FIG. 2 or otherwise create a loud noise or jack up one of the car wheels to move the sensor ball off the supporting contacts to actuate the electrical circuit, the sensor 40 (FIG. 4) within the electronic housing will register a tamper attempt. The tamper sensor then passes a tamper signal to the oscillator circuit 42 in the electronic housing which is responsive thereto to generate an oscillator signal. The oscillator signal is passed to the amplifier circuit 44 and amplified to generate the alarm signal. The alarm signal is conducted through the electrical conductors 62 (FIG. 5) within the hanger spring assembly 58 to the acoustic driver 26 (FIG. 4) in the alarm housing 18. The acoustic driver then responds to drive the acoustic transducer to generate an acoustic alarm broadcast through the sound grille 24 (FIG. 3) on the outwardly facing side of the alarm housing. The acoustic driver 26 (FIG. 4) vibrates the exciter cap 20 (FIG. 3) as it drives the acoustic transducer 28. The exciter cap is operative to impart vibration directly to the window 22 causing the window to propagate acoustical vibrations to reinforce the intensity of the audible alarm. It will be appreciated that the resilient bumpers 36 flex somewhat under the vibratory movement of such window, thus allowing for relatively uninhibited vibration of such window to thereby reinforce the propagation of sound waves. Propagation of this reinforced acoustic signal provides a substantial range of a highly intensive acoustic alarm which tends to deter all but the most persistent intruders. The high pitch affords a perceptible alarm at such a great distance that passers by are likely to be attracted to the violated automobile. When it is desirable to disarm or remove the alarm, the operator can open the car door, disarm the alarm, roll down the window and remove the alarm to be installed in another automobile.
From the foregoing it will be appreciated that the window mounted security alarm is portable and easily installed on automobiles, boats, and homes. The alarm apparatus design having the alarm siren outside of the automobile or other vehicle interior enables the alarm apparatus to generate an alarm much louder than would be the case if the alarm siren was within the interior of the automobile. The alarm apparatus provides a piercing 110 db alarm that is equivalent, because of its exterior positioning, to a 130 db under the hood mounted alarm. Importantly, the urged confrontation of the exciter cap against the window causes the window to vibrate in unison with the exciter cap, further measurably increasing the sound intensity of the acoustic alarm.
While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.
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A portable automobile alarm hung over the top of an automobile side window is secured in place by raising the window into its frame. The portion of the unit positioned on the interior side of the glass contains a sensor, a receiver, and associated electronic circuitry. The exterior unit houses an alarm siren. The unit is powered from an internal battery or from a cigarette lighter. The unit may be armed and disarmed by a remote transmitter.
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BACKGROUND OF THE INVENTION
The present invention relates to starting apparatus for internal combustion engines. More particularly, the invention relates to an improved engine starting apparatus of the type in which a starter motor having an output shaft disposed in parallel relation to the engine crankshaft has a pinion gear operatively connecting, through an intermediate gear shaft, a ring gear on the crankshaft.
Such a starting device is already known, for example, as disclosed in Japanese Utility Model Laid-Open No. 59-73580 (No. 75580/1984). In this prior art starting device, since the first and second gears of the intermediate gear shaft are arranged close to each other, the starter motor must be spaced a significant distance from the crankshaft so that the starter motor will not interfere with the driven member connected to one end portion of the crankshaft. This operates against reducing the space requirements of the engine.
In light of such circumstance, it is an object of the present invention to provide an engine starting device which permits arrangement of a starter motor close to the crankshaft without interferring with a driven member of the crankshaft whereby compaction of the engine can be better achieved.
SUMMARY OF THE INVENTION
In order to attain the aforesaid object, the present invention is characterized in that the shaft portion of the intermediate gear shaft is elongated between the gears it mounts and which operatively connect the starter motor pinion gear and the ring gear on the crankshaft, in such a manner that the intermediate shaft can be disposed close to the crankshaft.
With the aforesaid structure, since the shaft portion of the intermediate gear shaft is arranged at one side of the driven member, the starter motor is significantly axially spaced from the driven member. Accordingly, the starter motor can be arranged close to one side of the crankshaft without interference with the driven member.
For a better understanding of the invention, its operating advantages and the specific objectives obtained by its use, reference should be made to the accompanying drawings and description which relate to a preferred embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevational view taken along line I--I of FIG. 3 illustrating a motorcycle engine according to a preferred embodiment of the present invention;
FIG. 1A an enlarged cross sectional view illustrating a portion 1A in FIG. 1;
FIG. 2 is a right side view of the engine of FIG. 1;
FIGS. 3 and 4 are cross sectional views taken along line III--III and line IV--IV of FIG. 1;
FIG. 5 is an enlarged cross sectional view illustrating in greater detail the clutch transmission of FIG. 1;
FIGS. 6, 7 and 8 are cross sectional views taken along lines VI--VI, VII--VII and VIII--VIII of FIG. 3, respectively;
FIG. 9 is a cross sectional view taken along line IX--IX in FIG. 2;
FIG. 10 a cross sectional view taken along line X--X in FIG. 1;
FIG. 11 is a cross sectional view taken along line XI--XI in FIG. 10;
FIG. 12 is a cross sectional view taken along line XII--XII in FIG. 11;
FIG. 13 is a partially exploded side view illustrating the assembly of engine to the motorcycle;
FIG. 14 is a plan view of FIG. 13; and
FIG. 15 is a side view corresponding to FIG. 2 illustrating a variant of the engine according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The description that follows is directed first to the general structure of an engine and, thereafter, sequentially to a valve motion device, a timing transmission device, a breather device, a clutch, a transmission, a change mechanism, a lubricating device, a cooling device and a starting device.
First, FIGS. 1 to 4 depict an engine E for a motorcycle. The terms "front" and "rear" and "left" and "right" in regard to the engine E are as regards the orientation of the vehicle.
An engine body 1 of the engine E is provided with main components that include: a cylinder block 3 provided with four cylinders 2, 2, which are connected in series in the left and right directions and which are slanted somewhat forwardly; a crank case 4 integrally formed at a lower end of the cylinder block 3; a cylinder head 6 which is superposed on an upper end surface of the cylinder block 3 and which is fixed by bolts 5; a head cover 9 which is superposed on an upper end surface of the cylinder head 6 and which is fixed to a cam holder 47 mentioned hereinafter by a bolt 7 so as to define a valve motion chamber 8 between the head cover and the cylinder head 6; and a transmission case 10 which is integrally formed at the rear of the crank case 4. The three aforementioned members, that is, the cylinder block 3, the crank case 4 and the transmission case 10 are integrally formed from a casting. Right side surfaces and lower surfaces of the crank case 4 and the transmission case 10 are open, and a side cover 11 and an oil pan 12 are fixed on their open ends by bolts 13, 14.
On a wall of the crank case 4 are integrally formed a diaphragm wall between the respective cylinders 2, 2 and aligned crank journal supporting walls 15, 15 perpendicular to the outside walls of the cylinders 2, 2 at both outside positions. A crankshaft 16 positioned in the crankcase 4 is rotatably interposed between the crank journal supporting walls 15, 15 and a crank holder 18 fixed by bolts 17, 17 at the lower ends of the crank journal supporting walls. The crankshaft 16 is operatively connected to pistons 19, 19 movable in the cylinders 2, 2 through the intermediary of connecting rods 20, 20.
On a lower surface of the cylinder head 6 are provided a plurality of combustion chambers 21, 21 in alignment with the cylinders 2, 2. A ceiling surface of each combustion chamber 21 is formed in a crown shape having a ridgeline parallel to the crankshaft 16. At one slant surface of the crown shape are opened the inner ends of a pair of intake ports 22, 22 aligned along the ridgeline and at the other slant surface of the crown shape are opened the inner ends of a pair of exhaust ports 23, 23 aligned along the ridgeline. Outer ends of the intake ports 22, 22 open to the rear of the cylinder head 6 and outer ends of the exhaust ports 23, 23 open to the front of the cylinder head 6.
An ignition plug 24 for each combustion chamber 21 is arranged to be surrounded by the aforesaid intake and exhaust ports 22, 22; 23, 23 and is threadedly screwed to the cylinder head 6.
The intake valve 25 and the exhaust valve 26 that open and close each intake port 22 and each exhaust port 23 are slidingly guided for moving up and down by valve guides 27 and 28 fixedly provided on the cylinder head 6 and so arranged that the distance between both valves 25 and 26 increases toward the valve head.
On the intake and exhaust valves 25 and 26 are mounted valve springs 29 and 30 biasing the valves in their closing direction. In order to open the intake and exhaust valves 25 and 26 against forces of these valve springs 29 and 30, a valve motion device 31 is provided in the combustion chamber 8.
The valve motion device 31 comprises an intake camshaft 32 which is arranged just above the intake valves 25, 25 along the direction of alignment of the group of intake valves 25, 25; an exhaust camshaft 33 which is arranged just above the exhaust valves 26, 26 along the direction of alignment of the group of exhaust valves 26, 26; a rockable intake cam follower 36 which is supported on the cylinder head 6 by a pivot pin 34 at a base end thereof and which is inserted between the intake camshaft 32 and a head of each intake valve 25 at a free end thereof; and a rockable exhaust cam follower 37 which is supported on the cylinder head 6 by a pivot pin 35 at a base end thereof and which is inserted between the exhaust camshaft 33 and a head of each exhaust valve 26 at a free end thereof.
As shown in FIG. 3, the pivot pin 34 of the intake cam follower 36 is arranged between the exhaust valve 25 and the ignition plug 24, and the pivot pin 35 of the exhaust cam follower 37 is arranged between the exhaust valve 26 and the exhaust port 23. When thus constituted, the intake port 22 can extend upwardly from the combustion chamber 21 without interferring with the intake cam follower 36, so as not to restrict intake flow. Also, a sufficient space can be provided above the ignition plug 24 in order to attach and detach it without interferring with the exhaust cam follower 37.
As shown in FIG. 4, supporting bore 40 is provided in the lower surface of the free end of each cam follower 36, 37. Into this supporting bore 40 is loosely fitted a projecting shaft 41a which protrudes via a shim facing to the head of each of the corresponding intake and exhaust valve 25, 26. By selecting the thickness of the shim 41, the valve head gap of each intake and exhaust valve 25 and 26 is properly adjusted. Lateral deviation of the shim 41 is prevented by properly fitting the projecting shaft 41a within the supporting bore 40.
The intake camshaft 32 is rotatably interposed between a plurality of cam journal supporting walls 42, 42 provided upstanding from a bottom wall of the valve motion chamber and a cam holder 44 integral with the cam journal supporting wall fixed to the latter by bolts 43, 43. Also, the exhaust camshaft 33 is rotatably interposed between a plurality of cam journal supporting walls 45, 45 upstanding from the bottom wall of the valve motion chamber 8 and a cam holder 47 integral with the cam journal supporting wall fixed to the latter by bolts 46, 46.
These intake and exhaust camshafts 32 and 33 are connected with the crankshaft 16 through the intermediary of a timing transmission device 50.
The timing transmission device 50, as shown in FIGS. 1, 1A and 2, is contained in a timing transmission chamber 51 formed at the right end portions of the cylinder block 3, the cylinder head 6 and the head cover 9. The timing transmission device 50 comprises a drive gear 53 fixed to the right end portion of the crankshaft 16 through the intermediary of a key 52; a first idler gear 54 meshing with the drive gear 53; a second idler gear 55 which meshes with the first idler gear 54; an intake driven gear 56 which is substantially secured to a right end portion of the intake camshaft 32 and which meshes with the second idler gear 55; an exhaust driven gear 57 which is substantially secured to the right end portion of the exhaust camshaft 33 and which similarly meshes with the second idler gear 55; and a supporting plate 58 which supports the first and second idler gears 54 and 55 with bolts. The timing transmission device 50 is designed to transmit a rotation of the crankshaft 16 to both camshafts 32 and 33 with a reduction ratio of 1/2.
The aforesaid supporting plate 58 is pivotably mounted on the crankshaft 16 at one end thereof through the intermediary of a ball bearing 59 and is supported by a bearing shaft 60 which is threadedly screwed into the cylinder head 6. On the right side surface of the supporting plate 58 are provided a pair of outwardly projecting upper and lower bosses 61 and 62 on which the respective first and second idler gears, 54, and 55, are supported through the intermediary of the respective ball bearings 63 and 64.
As shown in FIG. 1A, a certain gap 66 in the form of an annular clearance space is provided between the bearing shaft 60 and an axial bore 65 provided in the supporting plate 58 to allow the bearing shaft 60 to penetrate therethrough. In order to restrain an oscillation of the supporting plate 58 due to the gap 66, resilient rings 67, 67, as, for example, O-rings, are disposed on the bearing shaft 60 as a pair of resilient spacer members contacting the inner surface of the axial bore 65.
Further, in the embodiment shown, the upper boss 61 and the axial bore 65 are concentrically arranged to render the supporting plate 58 more compact, but this construction is not necessary.
The bearing shaft 60 is threadedly screwed into an inner side wall of the timing transmission chamber 51 by a threaded portion 60 of the leading end thereof and is supported on an outer side wall of the chamber 51 by a circular head portion 60b through the intermediary of an O-ring 68. Accordingly, the bearing shaft 60 is supported at both ends.
In the aforesaid structure, the engine body 1 is formed of aluminum alloy, and the supporting plate 58 and the driver gear 53, as well as the driven gears 56 and 57, are formed of a material comprising iron compounds. Accordingly, the engine body 1 and the timing transmission device 50 differ largely in their thermal expansion coefficient. Further, during driving of the engine E, the engine body 1 is subject to greater amounts of heat than is the timing transmission device 50. Accordingly, the engine body E undergoes a greater degree of thermal expansion than does the timing transmission device 50. Therefore, if the distance between the crankshaft 16 and the bearing shaft 60 increases, since the bearing shaft 60, in moving, presses and deforms the resilient rings 67 and 67 within the gap 66 between the bearing shaft 60 and the axial bore 65 of the supporting plate 58, the aforesaid thermal expansion does not affect on the supporting plate 58. Consequently, the thermal expansion undergone by the engine E does not affect the distance between the shafts of the first and second idler gears rotatably supported on the supporting plate 58 or the distance between the shaft of the drive gear 53 on the crankshaft 16 and the first idler gear 54. Therefore, the backlash between the gears 53, 54 and 55 is always maintained substantially constant whereby the driving torque can be adapted to be properly and quietly transmitted by these gears from the crankshaft 16 to both camshafts 32 and 33.
Further, although the thermal expansion of the cylinder head 6 will have an affect on the backlash between the second idler gear 55 and the intake and exhaust driven gears 56 and 57, since the distance between the shafts mounting these gears is relatively short, the affect of this expansion can be expected to be very small. However, in the described device, in order to avoid the affect of thermal expansion, each of the driven gears 56 and 57 is divided into a stationary gear 69 substantially fixed to corresponding camshafts 32 and 33 and a movable gear 70 connected to the stationary gear 69 through the intermediary of a torsion spring 71. The teeth of the second idler gear 55 are resiliently interposed between the teeth of both gears 69 and 70 due to torsion force of the torsion spring 71 whereby it is intended to always exclude the backlash.
In the present invention, as shown in FIG. 15, the pivot shaft pivotably mounting one end of the supporting plate 58 may be formed as an intake camshaft 32 or an exhaust camshaft 33. In this case, it is unnecessary to provide the above described backlash-excluding mechanism between the second idler gear 55 and the intake driven gear 56 or the exhaust driven gear 57. However, it is desirable to provide the backlash-excluding mechanism between the drive gear 53 and the first idler gear 54.
Again, in FIG. 1, the left end portion of the crankshaft 16 projects into the crank case 4. On the projecting end is fixed a rotor 48a of a generator 48. A side cover 49 provided with its stator is fixed to the crank case by a bolt 72.
Next, a description is made about the breather device. As shown in FIGS. 1 and 3, on an upper surface of the cam holder 44 of the intake camshaft 32 side is integrally formed a surrounding wall 74 extending around a portion of the cam holder. In order to use the interior of the surrounding wall 74 as a breather chamber 75, the head cover 9 is made to abut an upper end of the surrounding wall 74 through the intermediary of a sealing member 76. The breather chamber 75 communicates with the valve motion chamber 8 through the intermediary of a bore 77 provided on the cam holder 44 and also communicates with the intake system of the engine E or the atmosphere through the intermediary of an introducing pipe 78 provided in the head cover 9.
Thus, when the breather chamber 75 is constructed by a part of the cam holder 44 and the head cover 9, it is unnecessary to provide an exclusive and independent breather chamber body thereby enabling the simplification of the structure of the breather device. Thus, during operation of the engine E, blow-by gas generated in the crank case 4 transfers to the valve motion chamber 8 through the timing transmission chamber 51, by entering from the bore 77 into the breather chamber 75 and expanding into the latter. After an oil fraction is separated in the breather chamber 75, the blow-by gas is discharged from the chamber 75 through the introducing pipe 78. The oil separated from the gas drops from the bore 77 into the valve motion chamber 8.
Next is presented a description of the clutch and the transmission. As shown in FIG. 1 and FIG. 5, in the transmission case 10 are contained the clutch 80 and the transmission 81. An input shaft 82 and an output shaft 83 of the transmission 81 are arranged parallel to the crankshaft 16, and between both the shafts 80 and 83 is provided a multistage transmission gear train consisting of gears 84a to 84n. Left end portions of the input and output shafts 82 and 83 are supported on the left side wall of the transmission case 10 through the intermediary of a needle bearing 85 and a ball bearing 88. Right end portions of the input and output shafts 82 and 83 are supported on a diaphragm plate 87 at the middle portion of the transmission case 10 through the intermediary of ball bearings 86 and 89.
The aforesaid diaphragm plate 87 is of circular shape and is fitted into an annular step portion 90 formed on an inner peripheral surface of the transmission case 10. The plate 87 is detachably fixed to a plurality of bosses 91, 91 formed on a peripheral wall of the case 10 by bolts 92, 92.
The right end portion of the input shaft 82 extends through the diaphragm plate 87 and on its leading end is fixed a clutch inner 93 of the clutch mechanism 80. A clutch outer of the clutch mechanism 80 is connected to the crankshaft 16 through the intermediary of a primary reduction device 95. The latter is comprised of a drive gear 96 of small diameter fixed on the crankshaft 16, and a driven gear 97 of large diameter attached to one side surface of the clutch outer 94 via a torque damper 98 and meshing with the drive gear 96. The driven gear 97 is supported on a spacer sleeve 99 on the input shaft 82 through the intermediary of a needle bearing 100. Thus, the clutch outer 94 is rotatably supported on the input shaft 82 through the intermediary of the driven gear 97. With such a structure the assembling performance is better and it is possible to confirm an actuation of the transmission 81 before assembling into the transmission case 10 since the transmission 81 can be assembled on the diaphragm plate 87 before fixing the diaphragm plate 87 to the transmission case 10.
Thus, during driving of the engine E, the output of the crankshaft 16 is transmitted to the clutch outer 94 via the drive gear 96 and the driven gear 97. During a connecting condition of the clutch 80, the resulting output torque is transmitted to the input shaft 82 via the clutch inner 93, and further, is transmitted to the output shaft 83 through the intermediary of one gear train selected from the transmission gear trains 84a to 84n. . Output torque of the output shaft 83 is transmitted to the rear wheels of the motorcycle through the intermediary of a second reduction device 101 so as to drive the rear wheels.
Next presented is a description of a change mechanism for changing and controlling the aforesaid transmission 81. In FIGS. 5 and 8, the change mechanism 104, as is well known, is provided with a change spindle 106 provided with a change pedal 105; a shift drum 108 forming columns of cam grooves 107 1 -107 3 on an outer periphery thereof; a step feed mechanism 109 which limits the rotary angle of the change pedal 105 and which gives the shift drum 108 a rotation of a required angle with the rotation of the change pedal 105; several shift forks 110 1 -110 3 which are engaged with cam grooves 107 1 -107 3 at one end thereof and with a sliding gear in the transmission gear trains 84a-84n at the other end thereof; and fork guides 111 1 , 111 2 which slidably support the shift forks. All of the change spindle 106, the shift drum 108 and the fork guides 111 1 -111 3 are arranged in parallel to the input and output shaft 82 and 83 of the transmission 81 and their opposite end portions are supported on the diaphragm plate 87 and the left side wall of the crank case 4, respectively. With such a structure, before fixing the diaphragm plate 87 to the transmission case 10, since the change mechanism 104 can be assembled on the diaphragm plate 87 together with the transmission 81, the assembling performance is better. Further, it is possible to confirm the actuation of the change mechanism 104 before assembling it into the transmission case 10.
Next, a description of the lubricating device is presented. Firstly, a description is presented of the lubrication systems of the crankshaft 16 and the valve motion device 31 with reference to FIGS. 1, 3, 5, 6 and 7. On the diaphragm plate 87 is provided an oil pump 114 of trochoidal type forming an oil supply source. That is, on the diaphragm plate 87 is formed a pump chamber 115 in facing relation to the driven gear 97 of the primary reduction device 95. In the pump chamber 115 are contained a radially outer rotor 116 and a radially inner rotor 117. On an open end of the pump chamber 115 is fixed a cover plate 118 by bolts 119. The inner rotor 117 is connected to the driven gear 97 through the intermediary of an Oldham's joint 120 penetrating through a center portion of the cover plate 118. By such a structure, during driving of the engine E, since the oil pump 114 can continue to be driven through the intermediary of the first reduction device 95, it is unnecessary to provide a driving gear train exclusively between the crankshaft 16 and the oil pump 114. Also, since the diaphragm plate 87 combines with the pump case to define the pump chamber 115, it is unnecessary to provide an exclusive pump case thereby simplifying the engine structure.
In the diaphragm plate 87 are provided an intake port 121 and exhaust port 122 opening into the pump chamber 115. To the intake port 121 is connected an intake pipe 124 rising from a strainer 123 provided below an oil surface in the oil pan 12. The exhaust port 122 is communicated with an oil gallery 126 through the intermediary of an oil passage 125. The latter is provided on a protruding portion 127 formed on an inner wall of the oil pan 12. Also, the oil gallery 126 is formed integrally with the crank holder 18 extending along its longitudinal direction. The oil gallery 126 has an inlet 126a connected to the oil passage 125 at a center thereof, the passage area being progressively widened from the inlet 126a toward left and right ends. From the oil gallery 126 are branched a plurality of oil feeding paths 128, 128 leading to a bearing surface to a journal of the crankshaft 16 and one oil feeding path 129 leading to a lubricating portion of the valve motion device 31.
Thus, with actuation of the oil pump 114, lubricating oil in the oil pan is induced through the strainer 123 and is fed under pressure to the oil gallery 126 via the oil passage 125. Further, the lubricating oil is distributed from the oil gallery 126 to portions of the crankshaft 16 and the valve motion device 31 requiring lubrication.
The lubricating oil in the oil pan 16, when passing the oil passage 125, is filtered by an oil filter 130 disposed in front of the oil pan 12. Inside the oil filter 130 is a filler chamber through which the oil passage 125 extends. In the filter chamber is set a filter element 131. Accordingly, oil flowing along the oil passage 125 is fed to the oil gallery 126, after being filtered in the element 131.
The front 12a of the oil pan 12 mounting the oil filter 130 is retracted from the front surface of the crank case 4. By this structure, it is possible to restrict into a small area the oil filter 130 projecting from a front surface of the engine E.
In the oil pan 12 is provided a relief valve 133 which restricts the upper limit of the exhaust pressure of the oil pump 114. On a bottom wall of the oil pan 12 are a pair of coaxially aligned inner and outer bosses 135 and 136 having a required distance 134 therebetween. In the outer boss 136 is provided a drain bore 137, and in the inner boss 135 is provided a valve bore 138 communicating with the oil passage 125 via the bore 137. Also, in this boss 135 is provided a lateral bore 139 opening the valve bore 138 to the oil pan 12. In the valve bore 138 are disposed a piston-like valve body 140 opening and closing the lateral bore 139, and a valve spring 141 biasing the valve body 140 in a direction closing the valve. A stopper ring 142 in the boss 135 supports an outer end of the valve spring 141.
Thus, when the exhaust pressure of the oil pump 114 exceeds the pressure limit set by the loading of the valve spring 141, the valve body 140 retracts by receiving the exhaust pressure and opens the lateral bore 139 thereby discharging the excess pressure from the oil passage 125 to the lateral bore 139 via the valve bore 138.
Into the outer boss 136 is threadedly screwed a drain bolt 143 closing the drain bore 137. The drain bolt 143 combines with a blind plug to close a machining port of the valve bore 138. Thus, when the drain bolt 143 is removed, oil stored in the oil pan 12 can be discharged through the drain bore 137. Due to the distance provided between the bosses 135 and 136, as mentioned above, there is no obstruction to the oil in flowing toward the drain bore 137.
Next, the lubricating system of the transmission 81 is described with reference to FIG. 5. In the diaphragm plate 87 are provided an exhaust port 122 of the pump chamber 115, and a first and second orifice 147 and 148 communicating with bearing housings 145 and 146 which contain the ball bearings 86 and 89 of the input and output shafts 82 and 83 therein. In the input shaft 82 is formed a hollow portion 82a that is closed at both ends, and further, are provided an inlet bore 149 which communicates the hollow portion 82a with the bearing housing 145, and a plurality of oil feeding bores 151, 151 which communicate the hollow portion 82a with sliding and rotating surfaces of the transmission gears on the input shaft 82. Also, in the output shaft 83 is formed a hollow portion 83a opened into the bearing housing 146 at one end thereof and further, are provided a plurality of oil feeding bores 152, 152 which communicate the hollow portion 83a with sliding and rotating surfaces of the transmission gears on the output shaft 83.
Thus, during actuation of the oil pump 114, a portion of the oil exhausted to the exhaust port 122 is fed to the bearing housings 145 and 146 in amounts controlled by the first and second orifices 147 and 148 to be introduced into the hollow portions 82a and 83a of the input and output shafts 82 and 83, respectively. A portion of the oil is distributed to the oil feeding bores 151, 151; 152, 152, respectively to lubricate each portion of the transmission gear trains 84a-84n.
When the lubricating system of the transmission 81 is thus structured, the oil passage connecting the oil pump 114 with the hollow portions 82a and 83a of the input and output shafts 82 and 83 is simplified whereby the oil feeding to the transmission 81 can be effectively performed.
Next, the cooling device is described. As shown in FIGS. 1, 10, 11 and 12, at the left side portions of the cylinder block 3 and the cylinder head 6 are integrally formed a pair of upper and lower housing sections 155a and 155b which are connected to each other by bolts 153 so as to construct a housing 155 of a water pump 154.
In the lower housing section 155b is formed an outflow port 157 which extends to an entrance port of a water jacket 156 surrounding the cylinders 2, 2 from the interior of the housing section 155b. Also present is an inflow pipe 158 opening to the center of the interior of the pump housing 155. To this inflow pipe 158 is connected a water hose 159 that extends to an outlet of a radiator, not shown. Also, the outlet of the water jacket 156 is communicated with an inlet port of the radiator, as is common in the prior art although not shown.
In the pump housing 155 is disposed an impeller 160. A pump shaft 161 driving the impeller 160 is supported on the upper housing section 155a through the intermediary of a pair of upper and lower bearings 162 and 163. This pump shaft 161 is arranged to extend into the valve motion chamber 8 at an upper end thereof. On the upper end of the pump shaft 161 is formed a driven gear 164 which meshes with a drive gear 163 fixedly provided on the intake camshaft 32. By such a structure, since the pump housing 155 of the water pump 154 can be formed by portions of the cylinder block 3 and the cylinder head 6, it is possible to simplify the structure of the water pump 154, and also, it avoids need for a particular piping for connecting between the pump housing 155 and the water jacket 156. Further, since the impeller 160 occupies a position which is relatively close to the camshaft 32, they can be interconnected by a relatively short pump shaft 161.
Next, a description of the starting device is presented. As shown in FIGS. 1, 2, 3 and 9, in consideration of weight distribution of the engine E, the starter motor 167 is connected to the crankshaft 16 at the center portion of the engine E in a depression 168 between the back surface of the cylinder block 3 and the upper surface of the crank case 4. A rotor shaft 169 of the starter motor 167 projects from the right end portion thereof, that is, at the end adjacent the timing transmission device 50. On the projecting end of the rotor shaft 169 is formed a pinion gear 170 which is connected to a ring gear 172 on the right end portion of the crankshaft 16 through the intermediary of a middle gear shaft 171. The middle gear shaft 171 comprises a rotary shaft 173 supported on the crank case 4 by a pair of left and right bearings 174 and 175; a gear 176 of large diameter which is fixedly provided at the left end of the rotary shaft 173 and which meshes with the pinion 170; and a gear 177 of small diameter which is fixedly provided at the right end of the gear shaft 173 and which meshes with the ring gear 172. The rotation of the pinion gear 170 can be transmitted to the ring gear 172 by two stage reduction. By adopting such a middle gear shaft 171, it is possible to make the ring gear 172 of a small diameter whereby it is possible to improve compactness of the engine E.
As clearly shown in FIG. 1, the ring gear 172 is rotatably supported on the crankshaft 16 by a needle bearing 178 and is connected to the crankshaft 16 through the intermediary of an overrunning clutch 179. The overrunning clutch 179 comprises a clutch inner 180 formed by a boss of the ring gear 172; a clutch outer 181 which is provided integrally at one end with the drive gear 53 of the timing transmission device 50 and which at the other end surrounds the clutch inner 180; and a clutch roller 182 which is interposed between the clutch inner 180 and the clutch outer 181. The driving force developed by this arrangement can be transmitted only in one direction from the clutch inner 180 to the clutch outer 181. Accordingly, if the starter motor 167 is actuated to start the engine E, the rotation of the rotor shaft 169 is reduced in the two stages by the middle gear shaft 171 as described above and is transmitted to the ring gear 172. The rotation, further, is transmitted to the crankshaft 16 through the intermediary of the overrunning clutch 179 so as to start the cranking of the crankshaft 16. If the engine E starts and the rotational speed of the clutch outer 181 of the overrunning clutch is higher than that of the clutch inner 180, the clutch is caused by the clutch roller 182 to enter an interrupting condition whereby overrunning of the starter motor 167 is prevented.
Finally, the structure for mounting the engine E on the motorcycle is described. In FIGS. 2, 13 and 14, the assembly consisting of the integral crank case 4 and transmission case 10 of the engine E has a pair of front hangers 185 integrally projected from its front portion and a pair of upper hangers 186 and lower hangers 187 also integrally projected from its rear portion.
The body frame F of the motorcycle includes a main frame 189 carrying a fuel tank 188 on an upper surface thereof and slanting rearwardly. From this frame F are provided a pair of left and right front brackets 190 and a pair of left and right rear brackets 191. The front hangers 185 are connected to the front bracket 190 by a bolt 192. The upper hangers 186 are connected to an upper portion of the rear bracket 191 by a bolt 193. The lower hangers 187 are connected to a lower portion of the rear bracket 191 by a bolt 194. Thus, the engine E is mounted on the vehicle body frame F.
With such a mounting structure, since the engine E has the structure as previously described, in a condition supporting the assembled body of the crank case 4 and the transmission case 6 on the vehicle body frame F, the crankshaft 16 can be removed downwardly together with the piston 19 and the supporting plate 58. This is performed by opening the left and right side covers 11 and 49 and the oil pan 12; by removing the crank holder 18 downwardly and further, by removing the bearing shaft 60 of the supporting plate 58 laterally. Similarly, the rotor 48a of the generator may be removed previously. Also, the transmission 81 and the change mechanism 104 can be taken out together with the diaphragm plate 87 by one effort, when the latter is taken out laterally after removing the second reduction device 101 from the output shaft 83 of the transmission 81, and removing the change pedal 105 from the change spindle 106.
Also, after removing the head cover 9, the connection between the cylinder head 6 and the cylinder block 3 is released, the cylinder head 6 can be taken out laterally from between the front bracket 190 and the front fork 195.
Accordingly, each of the described parts of the engine E can be attached and detached without removing the entire engine E from the vehicle body frame F, whereby maintenance of the vehicle can be very easily and rapidly performed.
It should be further understood that, although a preferred embodiment of the invention has been illustrated and described herein, changes and modifications can be made in the described arrangement without departing from the scope of the appended claims.
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In order to reduce the space requirements of an internal combustion engine the starter apparatus therefor includes an axially elongated intermediate gear shaft containing gears at each end, one of which meshes with the starter motor pinion and the other of which meshes with the ring gear on the crankshaft.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the field of heating, ventilating, and air conditioning systems. More particularly, the present invention comprises a heat pump with an integrated pressure reducer for reducing compressor workload in the cooling and heating cycles.
[0003] 2. Description of the Related Art
[0004] Various heating, ventilating, and air conditioning (HVAC) systems are known in the prior art. Heat pumps are HVAC systems which use a circulating refrigerant as a medium to absorb and move heat from the space to be cooled to another space and subsequently dump the absorbed heat out of the system. Heat pumps typically employ a reversing valve which allows the refrigerant to be circulated in one direction for cooling applications and another direction for heating applications.
[0005] A simplified schematic view of a HVAC heat pump is illustrated in FIGS. 1 and 2 . Heat pump 10 includes compressor 12 which is supplied with a liquefied refrigerant from accumulator 14 . FIG. 1 shows heat pump operating in a cooling state. In the cooling state, heat is collected from the inside of a house through interior coil 20 (acting as an evaporator) and rejected to the atmosphere through exterior coil 18 (acting as a condenser). Reversing valve 16 directs a stream of hot compressed gas to exterior coil 18 where heat is transferred to an outdoor heat sink. Although not shown in this illustration, a fan is typically used to increase convective heat transfer via exterior coil 18 . As heat is rejected to the heat sink (atmosphere) in exterior coil 18 , the hot compressed gas turns into a hot condensed liquid. The hot condensed liquid stream passes through bypass valve 24 in the direction of interior coil 20 . At the entrance of interior coil 20 , the hot condensed liquid passes through thermal expansion valve 26 where the stream expands into a cooled vapor stream. The cooled vapor stream passes through interior coil 20 and collects indoor heat. A receiver or dryer is typically used to collect condensed moisture, but has been omitted in the view. The cooled vapor stream eventually passes through reversing valve 16 and back to accumulator 14 .
[0006] FIG. 2 illustrates heat pump 10 operating in the heating mode. In the heating mode, reversing valve 16 directs a stream of hot compressed vapor from compressor 12 to interior coil 20 (which is acting as a condenser). Heat is released to the inside of the house when the hot compressed vapor stream passes through interior coil. A fan is customarily used to facilitate heat transfer via interior coil 20 . As heat is released through interior coil 20 the compressed vapor stream turns to a liquid state. The liquefied refrigerant stream passes through bypass valve 28 in the direction of exterior coil 18 . The liquefied refrigerant stream then passes through thermal expansion valve 22 where the refrigerant becomes a vapor and absorbs heat from the outside passing through exterior coil 18 (which is acting as evaporator). The vapor refrigerant is then directed back through reversing valve 16 to accumulator 14 .
[0007] The heating mode performance of HVAC systems are typically evaluated in terms of coefficients of performance (COP), and cooling mode performance is evaluated in terms of energy efficiency ratio (EER) or seasonal energy efficiency ratio (SEER). EER is essentially the ratio of cooling capacity in Btu/Hr and the input power in watts (W) at a given operating point. SEER is related to EER. While EER is evaluated with respect to a specific internal and external temperature, the SEER is determined over a range of expected external temperatures (the normal temperature distribution for the geographical location of the SEER test).
[0008] The amount of input power required to operate a heat pump is principally dictated by the workload and efficiency of the compressor. In the cooling mode, the compressor must generate a sufficient pressure differential to drive a hot compressed vapor stream through a thermal expansion valve. When cooling demands are elevated, the compressor requires even more input power.
[0009] Because energy costs for driving HVAC systems are so substantial, measures which improve a systems energy efficiency ratio and/or reduce the compressors workload are needed.
BRIEF SUMMARY OF THE PRESENT INVENTION
[0010] The present invention generally comprises a heat pump HVAC system with an integrated pressure reducer which reduces the head pressure of the system when operating in the cooling mode and thus reduces compressor workload. The heat pump HVAC system includes a compressor for compressing a refrigerant, an exterior coil positioned to exchange heat with the environment outside the building, an interior coil positioned to exchange heat with the interior of the building, and a reversing valve for changing the flow direction of refrigerant in the refrigerant circuit. A heat exchanger is provided between the outlet of the exterior coil and the thermal expansion valve. The heat exchanger cools the refrigerant flowing between the outlet of the exterior coil and thermal expansion valve using refrigerant exiting the interior coil.
[0011] The heat pump HVAC system of the present invention is able to attain a higher energy efficiency ratio (EER) and seasonal energy efficiency ratio (SEER) than an identical system which does not employ the pressure reducer. These performance gains are largely realized by the reduced head pressure of the system caused by cooling the refrigerant before it passes through the thermal expansion valve. The heat pump HVAC system of the present invention is able to achieve this reduced head pressure without significantly affecting the system's ability to move heat.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 is a schematic, illustrating a prior art heat pump operating in cooling mode.
[0013] FIG. 2 is a schematic, illustrating a prior art heat pump operating in heating mode.
[0014] FIG. 3 is a schematic, illustrating operation of the present invention in cooling mode.
[0015] FIG. 4 is a schematic, illustrating operation of the present invention in heating mode.
REFERENCE NUMERALS IN THE DRAWINGS
[0016]
[0000]
10
heat pump
12
compressor
14
accumulator
16
reversing valve
18
exterior coil
20
interior coil
22
thermal expansion valve
24
bypass valve
26
thermal expansion valve
28
bypass valve
30
heat exchanger
32
dryer filter
40
heat pump
42
first port
44
second port
46
third port
48
fourth port
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention, heat pump 40 , is illustrated in FIGS. 3 and 4 . FIG. 3 illustrates the operation of heat pump 40 in cooling mode and FIG. 4 illustrates the operation of heat pump 40 in heating mode. Reversing valve 16 may be selectively positioned in a heating position ( FIG. 3 ) or a cooling position ( FIG. 4 ) to control the direction a refrigerant flows through the heat pump circuit.
[0018] Turning to FIG. 3 , heat pump 40 is illustrated in the cooling mode. In the cooling mode, interior coil 20 acts as an evaporator and exterior coil 18 acts as a condenser. Reversing valve 16 , positioned in the cooling position, directs refrigerant flow from compressor 12 to exterior coil 18 . Exterior coil 18 is positioned outside of the building cooled by heat pump 40 and transmits heat from the refrigerant flowing through exterior coil 18 to a heat sink (such as the surrounding atmosphere). As heat is transmitted via exterior coil 18 , the refrigerant liquefies. In the cooling mode, bypass valve 24 is opened to direct refrigerant flow around thermal expansion valve 22 .
[0019] From bypass valve 24 , the refrigerant flows to heat exchanger 30 . Heat exchanger 30 acts as a counter-flow heat exchanger in which cooled refrigerant exiting interior coil 20 flows over a conductive conduit which transports the hot stream of refrigerant from exterior coil 18 to thermal expansion valve 26 . Heat is transferred from the hot stream to the cool stream in heat exchanger 30 .
[0020] The hot stream then passes through dryer filter 32 and evaporates to a cooled gas through thermal expansion valve 26 . Those that are skilled in the art know that the cooling of the gas is caused by the reduction in pressure of the gas as it passes through the expansion valve. The ideal gas law provides that the state of an amount of gas is determined by its pressure, temperature, and volume according to the equation:
[0000] PV=nRT
[0000] where P is absolute pressure, V is volume occupied by the gas, n is the amount of substance of gas (expressed in moles), R is the ideal gas constant and T is absolute temperature. In accordance with this relationship, reducing the pressure of a gas results in a corresponding reduction in temperature of the gas.
[0021] The cooled refrigerant vapor passes through interior coil 20 where heat from the interior of the building is transferred to the refrigerant passing through interior coil 20 . As mentioned previously, this refrigerant passes through heat exchanger 30 where it is used to cool the hot stream of refrigerant. From heat exchanger 30 the refrigerant passes back through reversing valve 16 before collecting in accumulator 14 .
[0022] Turning to FIG. 4 , heat pump 40 is illustrated in the heating mode. In the heating mode, interior coil 20 acts as a condenser and exterior coil 18 acts as an evaporator.
[0023] Reversing valve 16 , positioned in the heating position, directs hot compressed refrigerant vapor from compressor 12 to interior coil 20 . Interior coil 18 transmits heat from the refrigerant flowing through interior coil 20 to the interior of the building. As heat is transmitted via interior coil 18 , the refrigerant liquefies. In the heating mode, bypass valve 28 is opened to direct refrigerant flow around thermal expansion valve 26 .
[0024] From bypass valve 28 , the refrigerant flows through dryer filter 32 to heat exchanger 30 . In the heating mode heat exchanger 30 acts as a parallel-flow heat exchanger in which cooled refrigerant exiting exterior coil 18 flows over a conductive conduit which transports the hot stream of refrigerant from interior coil 20 to thermal expansion valve 22 . Heat is transferred from the hot stream to the cool stream in heat exchanger 30 .
[0025] The hot stream then evaporates to a cooled gas through thermal expansion valve 22 . The cooled refrigerant vapor passes through exterior coil 18 where heat from the outdoor air is transferred to the refrigerant passing through exterior coil 18 . As mentioned previously, this refrigerant passes through heat exchanger 30 where it is used to cool the hot stream of refrigerant. From heat exchanger 30 the refrigerant passes back through reversing valve 16 before collecting in accumulator 14 .
[0026] With the operation of the present invention now explained, the many advantages offered by the present invention may now be apparent to one that is skilled in the art. The reader will note that in both operating modes, heat exchanger 30 cools the “hot” stream of refrigerant before it passes through the thermal expansion valve. On a hot day, where ambient temperatures are approximately 100 degrees Fahrenheit, heat exchanger 30 may reduce the temperature of refrigerant flowing through thermal expansion valve 26 from 100 degrees Fahrenheit (in a conventional system operating without heat exchanger 30 ) to 40 degrees Fahrenheit (the temperature of refrigerant fourth port 48 of heat exchanger 30 ). This reduction in temperature (60 degrees Fahrenheit in preceding example) dramatically reduces the peak head pressure of heat pump 10 and the workload of compressor 12 . The heat pump HVAC system of the present invention is able to achieve this reduced head pressure without significantly affecting the system's ability to move heat. Thus, by adding heat exchanger 30 to an existing heat pump system, a user is able to attain a higher energy efficiency ratio (EER) and seasonal energy efficiency ratio (SEER).
[0027] Such a reduction in temperature and head pressure has been observed in multiple field tests. In these field tests, a reduced compressor “amperage draw” was also observed. In many cases, the amperage draw was reduced by as much as fifty (50) percent. As such, it is estimated that he addition of such a heat exchanger in the heat pump circuit as shown in FIG. 3 and FIG. 4 can approximately double the SEER rating of a HVAC system.
[0028] In addition, the proposed configuration of the preferred embodiment allows heat exchanger 30 to act as a counter-flow heat exchanger only during cooling mode. The reader will note that whether in heating or cooling mode, refrigerant always flows from third port 46 to first port 42 . In cooling mode, refrigerant flows from second port 44 to fourth port 48 ; however, in heating mode, refrigerant flows from fourth port 48 to second port 44 . This allows the AT (temperature differential measured from inlet to outlet) of the hot refrigerant stream passing through heat exchanger 30 to be maximized in the cooling mode where reducing the workload of compressor 12 is most beneficial.
[0029] Those that are skilled in the art will realize that the present invention may be easily retrofitted to existing heat pump systems without requiring the addition or replacement of expensive components (such as compressor 12 , interior coil 20 , or exterior coil 18 ). Further, heat exchanger 30 may be easily plumbed to the existing refrigerant circuit in minimal time. Such a retrofit has been performed in field tests. In one field test, a heat exchanger was added (as shown in FIGS. 3 and 4 ) to a 2.5 ton 13 SEER heat pump HVAC system. No components of the system were changed apart from the addition of the heat exchanger and the conduits and couplings needed to plumb the heat exchanger to the system. The system originally had a compressor amperage draw of 14.6 amps before the heat exchanger was added. After the heat exchanger was added, the amperage draw was measured to be 6.5 amps with a head pressure of 125 psi. This reduction in amperage draw boosts the efficiency rating of the system from 13 SEER to more than 26 SEER.
[0030] In these retrofit field tests it was further observed that the amount of liquid refrigerant passing through accumulator 14 into compressor 12 was substantially reduced when heat exchanger 30 was added to the heat pump circuit. Those that are skilled in the art know that an electric heater is often used to preheat refrigerant before the refrigerant enters the compressor since the presence of liquid refrigerant in the compressor can damage the compressor. Such a component is not needed in the proposed heat exchanger circuit because the refrigerant is heated in heat exchanger 30 before being transmitted to accumulator 14 . The removal of this electric heater would further reduce the total amperage draw of the HVAC system.
[0031] Although the preceding descriptions contain significant detail they should not be viewed as limiting the invention but rather as providing examples of the preferred embodiments of the invention. Accordingly, the scope of the invention should be determined by the following claims, rather than the examples given.
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A heat pump HVAC system with an integrated pressure reducer which reduces the head pressure of the system when operating in the cooling mode and thus reduces compressor workload. The heat pump HVAC system includes a compressor for compressing a refrigerant, an exterior coil positioned outside of a building, an interior coil positioned within the building, and a reversing valve for changing the flow direction of refrigerant in the refrigerant circuit. A heat exchanger is provided between the outlet of the exterior coil and the thermal expansion valve. The heat exchanger cools the refrigerant flowing between the outlet of the exterior coil and thermal expansion valve using refrigerant exiting the interior coil.
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FIELD OF THE INVENTION
[0001] The field of the invention is a method of expansion of tubulars downhole and more particularly expanding one tubular into contact with an open hole section where the added tubular is expanded into a supporting position by advancing the new tubular by moving it over an expansion device
BACKGROUND OF THE INVENTION
[0002] Monobore applications using expansion have integrated cementing through a shoe while covering a recess at the end of an existing string with a removable cover that comes off after cementing. A string with a swage is placed in position and the swage is energized to grow in diameter before being advanced through the newly added tubular until the swage exits the top of the added tubular to fixate it into the recess at the lower end of the existing tubular. The result is a monobore well. These designs have also disclosed a deployable shoe that can be delivered with the string prior to expansion and then tagged and retained as a swage moves through the string only to be reintroduced into the expanded string and sealingly fixated to it for the cementing operation. Examples of one or more of these method steps are illustrated in U.S. Pat. Nos. 7,730,955; 7,708,060; 7,552,772; 7,458,422; 7,380,604; 7,370,699; 7,255,176 and 7,240,731.
[0003] Methods that advance a swage through a tubular require the rig equipment to not only support the weight of the string to be expanded but also to be able to handle the applied force to the swage to advance it through the tubular to enlarge the diameter. The present invention reduces the surface equipment capacities needed to perform an expansion to create, for example, a monobore. It entails bracing the workstring to an existing tubular with the string to be expanded inside the existing tubular. The annulus around the work string is sealed and the swage is retained as annulus pressure around the running string advances the string to be expanded with respect to the stationary swage. Subsequently the expanded string is cemented and the expansion is completed by swage movement to exit the tubular that is now expanded, cemented and joined to the existing tubular. The bottom hole assembly that was used to deliver and expand the tubular into a supporting position is then retrieved to the surface. More details of the method will become readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while understanding that the full scope of the invention is to be determined from the literal and equivalent scope of the appended claims.
SUMMARY OF THE INVENTION
[0004] A string to be expanded is run in with a running string that supports a swage assembly. The running string is secured to the existing tubular and the top of the string to be expanded is sealed around the supported running string. The pressure applied to the annular space above the seal drives the liner over the swage. A cement shoe is affixed to the lower end of the string that is expanded after becoming detached from the running string assembly. When the expanded liner bottoms on a support, generally the hole bottom, the cement is delivered through the shoe and the expansion of the top of the string into a recess of the string above continues. The swage assembly with the seal and the anchor are then recovered as the running string is removed during the process of supporting the top of the expanded string to the lower end recess of the existing string already in the wellbore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a simplified diagram of the method showing the string to be expanded delivered to within the string that exists in the wellbore;
[0006] FIG. 2 is the view of FIG. 1 showing the string advanced over the swage assembly for expansion of the tubular string;
[0007] FIG. 3 is the view of FIG. 2 showing the cementing process;
[0008] FIG. 4 is the view of FIG. 3 showing the swage assembly raised to a location where expansion of the top of the string into a recess of the existing tubular can take place;
[0009] FIG. 5 is the view of FIG. 4 and shows the expansion assembly coming through the string at the close of expansion with the two strings joined and the expanded string cemented;
[0010] FIG. 6 is the view of FIG. 5 with the running string and expansion assembly fully removed;
[0011] FIG. 7 a is a view of the assembly at the bottom of the string to be expanded and the components that interact with those components that are located at the lower end of the running string;
[0012] FIG. 7 b shows the various configuration of the dual swage assembly in the various steps of the method;
[0013] FIG. 8 shows running in a coiled tubing version of the string to be expanded;
[0014] FIG. 9 shows the top of the string to be expanded being cut in an injector assembly;
[0015] FIG. 10 shows the running string run into the injector assembly;
[0016] FIG. 11 shows the running string tagged into the swage assembly;
[0017] FIG. 12 shows the string to be expanded positioned so that the swage assembly is below the lower end of the existing string;
[0018] FIG. 13 shows the installation of a top seal that will later permit pressurizing the annulus;
[0019] FIG. 14 shows pressure applied in the annulus above a seal to drive the string to be expanded over the swage assembly while the running string is anchored to an existing string;
[0020] FIG. 15 shows engaging the cementing shoe to the already expanded lower end of the string being expanded;
[0021] FIG. 16 shows continuation of expansion and the movement of displaced fluid during such expansion;
[0022] FIG. 17 shows release of the running string anchor and stabbing the expansion assembly into the cement shoe;
[0023] FIG. 18 shows pumping cement and the movement of displaced fluid from cementing;
[0024] FIG. 19 shows the cementing job finished;
[0025] FIG. 20 shows circulating out the excess cement;
[0026] FIG. 21 shows releasing the expansion assembly from the shoe and raising the expansion assembly to a position where expansion can continue;
[0027] FIG. 22 shows contacting the recess in the existing string with the top of the string being expanded;
[0028] FIG. 23 shows lowering the expansion assembly so that the larger swage can be collapsed;
[0029] FIG. 24 shows concluding the expansion with the smaller swage while the larger swage is collapsed.
[0030] FIG. 25 shows a bypass opened in the cup seal as the balance of the expansion concludes with the swage assembly engaging into the cup seal assembly;
[0031] FIG. 26 shows the cup seal assembly released from the liner top being expanded;
[0032] FIG. 27 shows the swage assembly coming out of the liner top;
[0033] FIG. 28 shows a set down force to collapse the smaller of the swages;
[0034] FIG. 29 shows movement down through the expanded string to confirm that it has the required drift dimension that allows the swage assembly to exit in a collapsed state;
[0035] FIG. 30 shows the assembly removed and the resulting extension of the well as a monobore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] A very simplified version of the method is illustrated in FIGS. 1-6 to show in general terms how it operates. A borehole 10 extends past an existing tubular 12 that has a recess 14 near its lower end. The recess 14 could have been placed there with an expansion tool that expanded the string 12 after it was originally placed in position in the wellbore 10 . A running string 16 delivers a string to be expanded 18 and has a top end seal 20 to close off the annulus 22 . Near the lower end of the running string 16 is a smaller swage 24 and a larger swage 26 shown in the collapsed condition. Preferably the swages are made of wedge segments that slide axially relative to each other to change between a collapsed dimension and an expansion dimension. The strings 18 and 16 can be coiled or jointed tubing. The string 18 can also have either a round or folded cross-section.
[0037] In FIG. 2 the pressure has been applied as indicated by arrow 28 to move the string 18 in a downward direction. Such movement acts to enlarge the swages to their desired diameters for expansion. The upper end 30 is not yet expanded leaving a gap 32 for fluid displacement when cementing begins as depicted in FIG. 3 .
[0038] In FIG. 3 the string 16 is tagged into a cement shoe that is not shown and cement is delivered into the annulus 34 . At the conclusion of cementing in FIG. 4 , the string 16 is released from the shoe (not shown) and the swages 24 and 26 are raised in a manner that only swage 24 is deployed. The cement in the unexpanded annulus 32 will remain in place until squeezed out of the liner top during liner lap expansion. The swage 24 is either pulled by string 16 or is driven up by pressure delivered through string 16 to below swage 26 to drive the swages 24 and 26 out through the string 18 to close the gap 32 as shown in FIG. 5 . FIG. 6 shows the expansion assembly removed and the resulting wellbore completed as a monobore with the drift diameter at 36 at least as large as the diameter at 38 .
[0039] From the detail offered thus far it can be seen that the string 18 is advanced over a stationary swage assembly 24 and 26 that is initially located below the existing tubular 12 that has a lower end recess 14 . After cementing, the balance of the expansion can take place by advancing the swages 24 in the expanded position and 26 in the collapsed position by literally pulling on the running string 16 or by delivering pressure though the running string 16 to then drive up the swage 24 by pressurizing space 40 that is below and within the string 18 .
[0040] In order to understand the details of the method, a more specific explanation of some of the introduced components will follow that also adds some new components. The detailed functioning of all the components will then be developed as the step by step description that then follows. Repeated in FIG. 7 a from FIGS. 1-6 are the liner 18 that is to be expanded with the swages 24 and 26 . The seal 20 seals around the running string 16 . The remaining components will now be introduced and discussed in greater detail. A selectively deployed anchor 42 is attached to the running string 16 and can be selectively deployed to the existing string 12 as will be explained below. The seal 20 has a central passage 44 and a stack of chevron seals 46 or some equivalent seal so that a seal can be maintained in annuls 22 as pressure represented by arrow 28 is applied and the seal 20 moves with the string 18 relatively to the stationary pipe 16 . It is preferred that the length of the running string 16 over which the seals 46 will travel should be polished to enhance sealing for at least the travel length of movement of seals 46 on the outside surface of the string 16 . The seal assembly 20 is secured to the string 18 by a breakable connection 48 . A connector tool 50 is at the lower end of the string 16 and can selectively engage the receptacle 52 above swage 24 . The connector tool 50 has lateral passages 54 and a through passage 56 . A series of bow springs 58 can serve as a centralizer as well as any equivalent device so that tagging into the receptacle 52 can be facilitated. A cement shoe 60 is schematically illustrated below the swage 26 . As will be explained below, the shoe 60 is designed to separate from the string 16 and sealingly anchor to the expanded portion at the lower end of the string 18 as will be explained in more detail below.
[0041] FIG. 7 b shows the four positions of the swages 24 and 26 during the practice of the method. In the first view both are collapsed for run in. In the second view both are expanded for initial expansion by the string 18 moving past as pressure is applied above seal 20 as indicated by arrow 28 . In the third view only swage 24 is activated for the finish of the expansion of the string 18 by either pulling with string 16 or pushing from behind swage 24 with pressure delivered through string 16 as swage 24 holds a seal against string 18 for the finish of expansion. In the final view both swages 24 and 26 are again collapsed for removal from the now secured string 18 .
[0042] FIGS. 8-30 detail the method for using coiled tubing for the liner 18 but the method is applicable to jointed tubing as well but different surface equipment will be used. The string 18 can be circular when run in or folded in a general figure eight shape as indicated by 62 . The main difference between using rounded string 18 to a folded version for running in is that the folded version 62 will need dual running strings 16 to reside in the wide portions of the figure eight shape to ensure that the folded shape transitions to round and that the expansion swage is loaded in a symmetrical manner.
[0043] In FIG. 8 a rig 64 is in position over the borehole 10 . Spool 66 has the string 18 that wraps around it and feeds out through a guide 68 and then through injectors 70 and 72 . It should be noted that typical well control equipment such as blowout preventers are omitted for clarity and added to that the drawings are also somewhat schematic so that details are omitted that are not significant to understanding the operation of the method. A flange 74 will subsequently accept a stuffing box as will be discussed with regard to FIG. 13 . The existing tubular 12 is already in position with a lower end recess 14 . The swages 24 and 26 and the shoe 60 are connected to the lower end of the string 18 before running into the wellbore 10 .
[0044] In FIG. 9 the string 18 is cut at 76 when the appropriate length has been fed off the spool 66 . The cut is made between the guides 70 and 72 and the cut end is dressed to sealingly accept the seal assembly 20 as will be discussed with regard to FIG. 10 .
[0045] In FIG. 10 the anchor 42 is affixed to the running string 16 as is the seal assembly 20 with the connector tool 50 then being attached to the string 16 . The string 16 can be a coiled tubing string fed off spool 78 . The packer cup assembly 20 is attached to the already dressed upper end of the string 18 using the breakable connection 48 . Anchor 42 at this point is still loosely fit to the string 16 .
[0046] In FIG. 11 the string 16 is advanced until the connector tool 50 latches into receptacle 52 so that the string 16 can take on the weight of the liner 18 . The running string 16 is picked up to insure it is supporting the liner 18 and if it is then the anchor 42 is attached to the liner 18 .
[0047] In FIG. 12 the swages 24 and 26 are lowered with the string 16 to below the lower end of the existing string 12 . In FIG. 13 a stuffing box 80 is secured at flange 74 . In FIG. 14 a pump truck 82 is connected with a line 84 to below the stuffing box 80 to result in a downward force represented by arrow 86 against the seal 20 . Before such pressure is applied however, the anchor 42 is set against the parent casing 88 so that the rig 64 is not stressed from the expansion operation that results from pressure advancing string 18 over the now deployed swages 24 and 26 that remain stationary because they are now supported by anchor 42 . The anchor 42 can be made responsive to deploy upon delivery of pressure represented by arrow 86 or alternatively by mechanical tension of running string 16 . Higher pressure than needed to set the anchor 42 then shears the connection between the liner 18 and the swages 24 and 26 as the liner 18 starts moving. The initial liner 18 movement builds the swages 24 and 26 to their full dimension with swage 26 being larger than swage 24 . A bell 90 forms at the lower end of string 18 as pressure on seal 20 advances string 18 over fully built swages 24 and 26 .
[0048] In FIG. 15 the shoe 60 releases from swages 24 and 26 and deploys sealingly against the now expanded bell 90 at the lower end of the string 18 . A seal and slip assembly is schematically illustrated at 92 to show the shoe 60 secured to the string 18 for subsequent cementing. FIG. 16 shows the liner 18 continuing to advance and displace fluid as it does so. The displaced fluid is represented by arrows 94 , 96 and 98 that then enter ports 100 in the seal assembly 20 . From there the flow continues into annulus 102 as indicated by arrows 104 and 106 and into ports 54 of connector 50 . From there the flow can go into space 40 whose volume grows as the liner 18 moves downhole, as illustrated by arrow 110 or uphole through the liner 18 as illustrated by the arrow 108 . As an alternative to the above flow scheme the cement shoe 60 can have its ports 112 held open to take returns into space 40 and when the initial expansion is done the check valves (not shown) in the shoe 60 can be enabled to stop flow into space 40 when the cementing later takes place.
[0049] The expansion stops in FIG. 17 just short of the recess 14 and the removal of pressure unsets the anchor 42 . The work string 16 is advanced to tag the swage assembly into the cement shoe. The connection to receptacle 52 can be confirmed with a pickup force to run in string 16 . At this time the string 16 is latched through to the cement shoe 60 and cementing can begin.
[0050] In FIG. 18 a lead plug 114 has been dropped ahead of the cement being added to close off ports 54 that schematically are no longer shown in the connector 50 . The plug 114 has a passage through it temporarily blocked by a rupture disc (not shown) so that the delivered cement goes straight through the connector 50 and out the ports 112 as indicated by arrows 116 . At this time the seal assembly 20 is out of contact with the recess 14 so that fluids displaced by the flowing cement go uphole and past the unset anchor 42 as indicated by arrows 118 and 120 . Arrow 122 represents cement delivery through the string 16 . FIG. 19 shows the cement delivered to fill the gap 32 and the plug behind the cement (not shown) bumped against the lead plug 114 (not shown in this view). The cement pumps can be turned off at this time. FIG. 20 shows the shoe 60 released by the swages 24 and 26 which has the effect of closing ports 112 in opposed directions to flow. Circulation flow represented by arrow 124 down the string 16 removes excess cement that then travels through the end of the string 16 represented by arrows 126 , 128 and 130 through ports 100 and up to the surface as represented by arrows 132 . This circulation can be repeated as expansion is resumed to remove further displaced cement out of gap 32 as gap 32 is closed by continuing expansion.
[0051] In FIG. 21 the string 16 is picked up to engage swage 24 that is now built and close off the ability for flow to bypass the swages 24 and 26 . The swage can seal metal to metal upon expansion contact or there can be a sealing tool independent of the swages above or below the swages that allows for pressure buildup behind the swages 24 and 26 as represented by arrows 134 . While initial overpull helps to obtain the seal, thereafter pressure applied as indicated by arrows 134 helps to maintain the seal so that the swage 24 can be powered up to continue expansion of the liner 18 to close the gap 32 by displacing cement out of it. In FIG. 22 the smaller swage is in the recess 14 and the larger swage 26 is just below recess 14 . The lap 136 is now anchored and sealed.
[0052] In FIG. 23 the string 11 is lowered and pressure is applied in the string 16 as indicated by arrow 138 and in the annulus as indicated by arrow 140 at the same time. The net result is that the larger swage 26 is collapsed while swage 24 continues to be in the built condition for further expansion. The annulus pressure represented by arrow 140 goes through ports 100 and into space 40 . There is no flow past seal 20 because of the balanced pressure applied in the string 16 .
[0053] In FIG. 24 the swage 24 is raised to sealing contact with the liner 18 and pressure is only applied in the string 16 represented by arrow so that the liner lap is made longer as hanger seals and slips on the string 18 (not shown) are brought into contact with the recess 14 . In FIG. 25 the expansion has continued until the connector 50 bumps the seal 20 so that they attach to each other and that opens the bypass for the seal 20 that is schematically illustrated as 142 . The removal of the string 16 past the recess 14 will not allow for pulling a wet string or swabbing the well because the bypass openings 142 are open.
[0054] Further movement of the string 16 in FIG. 26 breaks the connection 48 of the seal 20 to the liner 18 . Continued pumping allows the swages 24 and 26 to exit the liner 18 at the top, as shown in FIG. 27 with the swage 24 still in the recess 14 . A set down force as shown in FIG. 28 allows the swage 24 to collapse. The force can be from simply setting down weight or applying annulus pressure to create an impact force to collapse the swage 24 .
[0055] FIG. 29 shows an option trip downhole to check drift with the seal assembly 20 . The movement of the seal assembly 20 can be aided with pressure for both uphole and downhole movement of the seal assembly 20 . In the FIG. 29 position the borehole 10 can be pressured to test the integrity of the connection between the liner 18 and the existing tubular. FIG. 30 shows the string 16 and the equipment mounted to it removed from the well 10 .
[0056] Those skilled in the art will appreciate that the method allows for completion of a well by adding a string and connecting it to an existing string involving an expansion that features advancing the string to be expanded over a swage assembly using pressure provided above a seal that moves with the string being expanded. The expansion takes place from the bottom up and employs variable swage devices that build to a first size for initial expansion and then to a smaller size inside a recess of the existing tubular so that the seal and swage assemblies can ultimately exit from the tubular being expanded and the existing tubular. In the preferred embodiment a monobore completion is achieved. The expansion is in stages with cementing taking place while a gap exists between the tubular being expanded and a lower end recess in the existing tubular. The seal assembly is bypassed in the recess of the existing tubular during cementing. A bypass opens in the seal assembly for ultimate removal to prevent pulling a wet string or swabbing the formation. The running string is anchored in the well against tension applied from forcing the tubular being expanded over a stationary swage assembly. The swage assembly uses two swages having different diameters that can both be deployed for the initial expansion and where a smaller of the two is deployed for connecting the top of the string being expanded to a lower end recess of an existing tubular. The string to be expanded can be jointed tubing or coiled tubing and its initial shape can be round or folded, such as in a generally figure eight shape, for example. The figure eight shape can use two running strings deployed in the wide portions of the folded string so that the act of driving the string over the swage assembly will not put harmful moments on the tubular that is being unfolded and expanded as it is driven past the swage assembly.
[0057] The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.
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A string to be expanded is run in with a running string that supports a swage assembly. The running string is secured to the existing tubular and the top of the string to be expanded is sealed around the supported running string. The pressure applied to the annular space above the seal drives the liner over the swage. A cement shoe is affixed to the lower end of the string that is expanded after becoming detached from the running string assembly. When the expanded liner bottoms on a support, generally the hole bottom, the cement is delivered through the shoe and the expansion of the top of the string into a recess of the string above continues. The swage assembly with the seal and the anchor are then recovered as the running string is removed during the process of expanding the top of the expanded string into the lower end recess of the existing string already in the wellbore.
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FIELD OF THE INVENTION
[0001] The present invention concerns an apparatus for grinding organic waste, like kitchen waste that has to be collected and disposed of.
BACKGROUND OF THE INVENTION
[0002] Known apparatus of the field of the invention that grind the kitchen waste to reduce its volume, are described in EP 1707270, in PCT/EP2007/005793 (not published), in Italian application PI2007/000050 (not published).
[0003] These apparatuses achieve that an increased amount of ground waste can be stored in disposal collectors, like the recyclable garbage bags commonly used by the public. Furthermore, the resulting ground waste can be more effective for composting processes, and thus provides an important contribution to ecology.
[0004] The mentioned apparatuses foresee a cleaning cycle which uses a mixture of water and sanitizing liquid. Once the cycle has been completed, the mixture can be eliminated through a piping system which is connected to a collection container of the apparatus that can be emptied, or to the drain system of the kitchen. Therefore, the apparatuses require connection to the water supply, and in many cases also to a drain system.
[0005] Sanitizing and cleaning of the equipment needs to be carried out thoroughly. Furthermore, the process and products for sanitizing and cleaning should not be harmful for the environment.
[0006] One of the inconveniences to be avoided in these types of machines is that waste residues remain attached to the internal walls of the apparatus, which complicates cleaning of the surfaces where the attachment occurs.
[0007] However, the use of a mixture of water and sanitizing liquid needs to occur frequently because the effect of the sanitizing liquid on the walls is limited due to its evaporation and dripping away with the water of the mixture.
[0008] The use of water and sanitizing liquid, together with the provision of a cleaning cycle, require that the apparatus be positioned near a water supply and a drain system of the kitchen. This can be a problem for who is not able to position the apparatus according to these requirements.
[0009] In addition, the use of cleaning and sanitizing liquid and the provision of a cleaning cycle require that the apparatus be provided with supplementary parts like internal valves or containers for deviating the liquids towards the drains and the collection devices. These supplementary parts increase the space occupancy of the apparatus.
SUMMARY OF THE INVENTION
[0010] It is an object of the invention to provide an apparatus for grinding solid portions of the waste, like kitchen waste wherein more simplified and less task of cleaning is possible for surfaces exposed to contact with the waste.
[0011] It is another object of the invention to provide an apparatus for grinding solid portions of the waste, like kitchen waste, wherein the decomposition of the waste is controlled by using predetermined quantities of cleaning or sanitizing products.
[0012] It is also an object of the invention to provide such an apparatus wherein the effect of the cleaning or sanitizing products on the internal surfaces of the machine lasts longer.
[0013] It is a further object of the invention to provide such an apparatus wherein it is no longer necessary to perform cleaning/sanitizing cycles with liquid products.
[0014] It is a further object of the invention to provide such an apparatus that does not require connection to the water supply or to a drain system for liquids.
[0015] It is a further object of the invention to provide such an apparatus having a reduced size, and which can be positioned in kitchens where little space is available.
[0016] Theses and other object are achieved with the apparatus of claim 1 of the present application.
[0017] In substance, the apparatus foresees a loading section for loading the waste material that needs to be treated, a grinding section for grinding the waste material that has been loaded, means for collecting the solid waste that has been ground, means for dispensing controlled quantities of powder for sanitizing and/or cleaning.
[0018] The predetermined quantities of powder can be dispensed on the waste material present in the loading section and/or on the surfaces of the loading section. Furthermore, the powder can be dispensed on the waste material that has been ground and is collected in the collecting means.
[0019] In particular, the powder comprises known powder compounds, for example biological types consisting of enzymes, which avoid transformation into substances that are hazardous for the health or are a source of bad smell. For example, although not exclusively, powder composition can be used containing proteinaceous nitrogen, enzymes, vitamins, micro-elements, macro-elements or compositions like those described in EP 0878202, based on bacteria and enzymes, used for sanitizing and deodorizing road side garbage containers.
[0020] The powder dispensed on the parts of the apparatus, like the walls of the loading section and the grinding means reduce the possibility of attachment of the waste to the treated surfaces. In fact, the powder remains attached to the surfaces and there forms a protective veil where the waste will contact without becoming attached, or if attachment occurs, cleaning will be easier during an eventual cleaning cycle that occur periodically. In particular, the enzymes reduce the possibility that the waste remains attached to the internal walls of the apparatus, thereby simplifying cleaning of those surfaces that come in contact with the waste.
[0021] An embodiment of the invention foresees a powder feeding unit comprising a ventilator and a member for fluidizing the powder. The ventilator produces a flow of air that fluidizes a powder bed. A mixture of air and powder is formed over the bed. The mixture is conveyed to various locations of the apparatus. For example, the mixture can be conveyed to the loading section and/or to the collection section for the ground waste.
[0022] In the loading section of the waste, a distributor can spray the mixture of air and powder on the loaded waste, or on the surfaces of the apparatus that are not in contact with the waste.
[0023] A nozzle system can be foreseen near the collecting means for spraying the powder on the ground waste, when the latter is being collected in the collecting means.
[0024] A second embodiment foresees a rotating surface that is capable of producing an air flow, which engages the particles of powder and sprays them in a distributed manner on the surfaces of the apparatus.
[0025] A third embodiment foresees that the user of the apparatus actuates a piston mechanism for creating a flow of air whic sprays the powder in the apparatus.
[0026] According to another aspect of the invention, a method is provided for grinding organic waste, like kitchen waste, as defined in claim 14 .
[0027] The apparatus of the invention can be used as a stand alone unit with the advantage that it can be positioned in a variety of locations seeing that water or drain connections for liquids may not be required.
[0028] Furthermore, the apparatus of the invention can be foreseen without requiring supplementary parts, like internal valves or containers for deviating the liquids towards the drains and collection devices, or these parts can result more simple and reduced in dimensions.
[0029] According to another aspect of the invention, an apparatus for grinding waste comprises a section for loading the waste; a section for grinding the waste; a section for collecting the waste; and the characteristic that the apparatus can be positioned under the sink unit of a kitchen. In particular, the apparatus has a depth between 30 and 54 cm, a height between 40 and 75 cm and a width between 15 and 60 cm. Preferably, the apparatus has a height which is less than 50 cm.
[0030] In a preferred embodiment, the loading section comprises a portion that is extractable from a fixed structure, therefore the waste can be loaded in the loading section from above by extracting the extractable portion from under the sink unit. The apparatus that can be positioned under the sink unit foresees means for dispensing predetermined quantities of sanitizing/cleaning powder on the waste or on the internal surfaces of the apparatus.
[0031] The apparatus of the invention can also foresee, for certain embodiments, cleaning cycles using liquids and relative draining of the liquids. However, the cleaning cycles can be performed less frequently and more effectively due to the use of powder which impedes the waste from attaching to the internal walls.
[0032] Furthermore, the apparatus according to the invention can be provided with a collection container for the ground waste, which is connected to the structure of the apparatus by means of a sealing joint to avoid that bad smell escapes. At the same time, the container is easily removed and connected to the apparatus when operations of emptying the ground waste are required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Further characteristics and the advantages of the apparatus according to the invention will result from the following description of some specific embodiments, which are made for exemplary reasons and without being limitative, and with reference to the accompanying drawings.
[0034] FIG. 1 is an elevation partial section view of an apparatus for grinding waste, illustrating a first embodiment of the invention.
[0035] FIG. 2 is a prospective view as seen from direction 2 of FIG. 1 .
[0036] FIG. 3 is a section view as seen from directions 3 - 3 of FIG. 2 .
[0037] FIG. 3 a is a section view as seen from directions 3 A- 3 A of FIG. 3 .
[0038] FIG. 4 is a partial section view similar to a portion of the view of FIG. 1 illustrating a second embodiment of the invention.
[0039] FIG. 5 is a partial section view similar to a portion of the view of FIG. 1 illustrating a third embodiment of the invention.
[0040] FIG. 6 is a partial section view similar to the view of FIG. 1 illustrating the apparatus of the invention positioned in the space, like is available under the sink unit of kitchens.
[0041] FIG. 7 is a view as seen from direction 7 of FIG. 6 .
[0042] FIG. 8 is a partial section view similar to the view of FIG. 1 illustrating the apparatus of the invention with a collection container connected to the apparatus in a sealed manner.
[0043] FIG. 9 is a prospective view as seen from direction 9 of FIG. 8 illustrating the solution for connecting the collection container.
DETAILED DESCRIPTION
[0044] With reference to FIG. 1 , kitchen waste W can be placed by a user in basin 10 of loading section 11 . From this position the waste can fall by gravity on the surface of grinding rollers 12 (shown with dashed line representation in FIG. 1 ). The grinding rollers can be like those described in above mentioned Italian application. The waste that has been loaded in basin 10 is conveyed towards the central area of the rollers so that grinding can occur.
[0045] The ground waste that exits the rollers from side 13 falls for example in a bag (not shown) placed in collection bin 15 . Any liquid waste that is passed in the loading section can drip through the spacing existing between the rollers 12 , and thus reach the collection bin 15 . Alternatively, a liquid collection system (not shown) can be present on side 13 for collecting the liquid in a container which is connected to a discharge tube of the apparatus, like has been described in the above mentioned applications cited in the introductory part of the description.
[0046] The powder dispensing solution as illustrated in FIGS. 1-3 a foresees a unit 14 for feeding the powder, which comprises chamber 16 , ventilator 17 and piping 18 . Unit 14 is assembled on a trolley structure 26 ( FIGS. 1 and 3 ), which also supports bin 15
[0047] Ventilator 17 is connected by means of conduit 17 ′ to member 19 for fluidizing the powder (see FIGS. 2 and 3 ). Member 19 is positioned near the bottom of chamber 16 . Member 19 can be a tube with bores facing the overhead space of chamber 16 . Chamber 16 is provided with a loading channel 21 , which can be opened at entrance 21 ′ by removing tap 16 ′. This allows the user to load the powder through channel 21 .
[0048] At the bottom of channel 21 , a motorized valve 22 can release predetermined quantities of powder in chamber 16 to guarantee that a predetermined level of powder bed PB is present over fluidizing member 19 . The air flow coming from ventilator 17 , and which is distributed by member 19 , fluidizes the powder bed PB. This creates a mixture of air and powder PM which fills space A above the powder bed.
[0049] Due to a sufficient pressure produced by ventilator 17 , the mixture of air and powder PM flows though piping 18 to reach distributor 20 present in the loading section and the nozzle system 25 located in the collecting section of the waste, as shown in FIG. 1 .
[0050] Distributor 20 is located over basin 10 where waste to be treated is loaded (see FIG. 1 ). Distributor 20 is provided with outlet openings 20 ′ that allow the mixture of air and powder PM to be uniformly sprayed in loading section 11 . In this way, the powder can be deposited on waste present in basin 10 , or on the exposed surfaces of the apparatus.
[0051] The mixture PM also reaches nozzle system 25 for dispensing the powder on ground waste material that is deposited in bin 15 . Depositing the powder on the ground waste can be an alternative to depositing powder on the waste in the loading section, or it can be an additional measure to increase prevention of the formation of hazardous substances and source of bad smell.
[0052] When the waste is not present in basin 10 , the powder can be sprayed by distributor 20 so that it deposits on the walls of basin 10 , and also on the surfaces of grinding rollers 12 . The grinding rollers 12 can be rotating when this occurs. This exposes all the surfaces of the grinding rollers to the spray of powder.
[0053] Control unit 23 of the apparatus can be programmed to activate ventilator 17 when spraying of the powder needs to occur in loading section 11 and through nozzle system 25 . Control unit 23 can also activate valve 22 for delivering the powder in chamber 16 so that the level of bed PB is maintained constant.
[0054] Valve 22 can be provided with compartments 22 a - 22 d located around axle 22 e , like is shown in FIG. 3 a . Predetermined volumes of powder fill each compartment 22 a - 22 d for being intermittently dropped into chamber 16 by means of rotation of axle 22 e caused by motor drive 24 and control unit 23 . The rotations of axle 22 e are started and stopped by control unit 23 to maintain the predetermined level of the powder bed PB in chamber 16 . Sensors (not shown) can detect the level of the powder bed, and therefore cause motor drive 24 to rotate valve 22 . Further sensors (not shown) can detect the level of powder present in loading channel 21 and therefore signal requirement of replenishing unit 14 with powder.
[0055] The timing that ventilator 17 remains actuated is controlled by control unit 23 . This timing can influence the quantity of powder that becomes sprayed in the apparatus by distributor 20 and by nozzle system 25 . Control unit 23 can be programmed, for example, for causing dispensing of powder at regular intervals of the working time of the apparatus, or based on the occurrence of working cycles of the apparatus.
[0056] The user can easily reach entrance 21 ′ of channel 21 by drawing trolley structure 26 in direction 26 ′. This will result in aligning entrance 21 ′ with the user present outside the apparatus. Trolley structure 26 is drawn in direction 26 ′ also for allowing the user to access collection bin 15 when needing to remove the ground waste from the apparatus.
[0057] The user can directly actuate dispensing of powder on behalf of unit 14 by actuating a switch of control unit 23 . Furthermore, the user can change the number of cycles for dispensing the powder, the timing that ventilator remains operative, and the timing that valve 22 remains activated. All this for modifying the conditions and quantity of powder being dispensed in the apparatus.
[0058] A deviation valve 18 ′ activated by control unit 23 can deviate flow of powder between piping going to distributor 20 and piping going to the nozzle system 25 , or can maintain the flow in both piping.
[0059] A further embodiment of the invention for dispensing powder in the loading section is shown in FIG. 4 . The solution of FIG. 4 can be a unit 40 located overhead the loading section in central area 41 , see FIG. 1 .
[0060] Unit 40 does not require an air flow for dispensing the powder. The powder P can be stored in loading chamber 30 of unit 40 . A calibrated opening 31 at the bottom of chamber 30 communicates with channel 32 of the support structure 33 of unit 40 . Channel 32 has a calibrated opening 32 ′ which communicates with a second channel 34 of support structure 33 .
[0061] A predetermined quantity of powder 49 can fall through opening 31 into channel 32 when push shaft 47 moves rearwards in direction X′ to open opening 31 towards channel 32 .
[0062] Channels 32 and 34 are parallel to each other and extend longitudinally in direction X. Channel 34 is located below channel 32 . Opening 32 ′ is located more forward than opening 31 in direction X.
[0063] Opening 34 ′ near to the end of channel 34 communicates with area 35 of support structure 33 . Area 35 has a conical configuration which expands from opening 34 ′ towards basin 10 .
[0064] A rotor 36 having a conical configuration is located in section 35 . Rotor 36 is supported by shaft 37 , which is assembled on bearings 38 located in support structure 33 . Shaft 37 is rotated by motor 39 so that rotor 36 is rotated around central axis 40 ′ of section 35 .
[0065] Actuator member 42 has a rack portion 42 ′ which engages pinion 43 of motor 44 . Bidirectional rotations of motor 44 translate member 42 backwards and forwards, i.e. respectively in directions X and X′. Rod 45 is an extension of member 42 , and translates in channel 32 for the same translations accomplished by member 42 . Similarly, pusher rod 46 is an extension of member 42 and translates in channel 34 for the same translations accomplished by member 42 . Pusher rod 47 is more forward than pusher rod 45 in channel 32 , whilst spring 48 is assembled between rod 45 and rod 47 .
[0066] FIG. 4 shows an operative instant of unit 40 , in which rod 46 is pushing a predetermined quantity of powder 49 through channel 34 . The pushing direction is X towards opening 34 ′ of section 35 . When the powder reaches opening 34 ′, it falls on rotor 36 which is rotating around axis 40 ′. The engagement of the powder on the rotor that is rotating causes the powder particles to be launched out of section 35 , and therefore dispenses the powder particles into loading section 11 .
[0067] The predetermined quantity of powder 49 reaches channel 34 in a previous stage when rod 47 has pushed the powder along channel 32 to make it drop though opening 32 ′. In an even previous stage, rod 47 has been sufficiently moved in direction X′ to clear opening 31 , and therefore to allow the predetermined quantity of powder to drop from loading chamber 30 into channel 32 through opening 31 .
[0068] As shown in FIG. 4 , spring 48 allows rod 47 to engage the end of channel 32 and at the same time allows rods 45 and 46 to continue to translate in direction X, when rod 46 needs to push the powder in channel 34 towards opening 34 ′.
[0069] The sequence of translation of rods 45 , 47 and 46 are caused by the sequence of rotations of motor 44 , which can be controlled by control unit 23 to guarantee that predetermined quantities of powder are pushed and caused to fall on rotor 36 , or the user of the apparatus can directly activate motor 44 by means of switches of control unit 23 for causing the predetermined quantity of powder to be pushed and made to fall on rotor 36 .
[0070] Unit 60 shown in FIG. 5 is a further embodiment that can be applied for dispensing powder in the loading section 11 . With unit 60 , the user presses on piston 61 to move it in air tight chamber 62 . In this way a an air flow is caused through piping 63 which pressurizes chamber 64 .
[0071] Slide member 65 is like a piston member which can translate in chamber 64 due to the push obtained by the pressurized air coming from chamber 62 . Slide member 65 has passage 65 ′ which can be aligned with opening 66 of powder reservoir 67 , as shown in FIG. 5 . The alignment of passage 65 ′ with opening 66 causes a predetermined quantity of powder to fill passage 65 ′.
[0072] The air flow caused by the user pressing piston 61 translates member 65 in direction X′, which therefore aligns passage 65 ′ both with passage 70 and with air exit 71 . During the translation of member 65 , entrance 72 of by pass duct 73 is opened to deviate a portion of air flow to reach air exit 71 .
[0073] Passage 70 is an exit for spraying the powder in loading section 10 . Diffusion members at the exit of passage 70 , enlarged section 74 and cone 75 , cause the powder to be sprayed out from passage 70 onto a vast area of the loading section. Therefore, when passage 65 ′ is aligned with passage 70 and air exit 71 , the air leaving 71 sprays the powder out of passage 65 ′ through passage 70 and into the loading section 11 .
[0074] During translation of slide member 65 in direction X, spring 76 becomes preloaded. When piston 61 is released, the preload of the spring translates slide member 65 in opposite direction X to bring slide member back into engagement with cap member 62 ′, thereby returning the situation to the condition of FIG. 5
[0075] Distributor 20 and units 40 , 60 can be assembled in a portion 50 of the apparatus structure (see FIG. 1 ). Portion 50 of the apparatus structure can function as a lid for allowing access and for closing the loading section 11 . The lid can be rotated by means of hinges (not shown) in directions Y and Y′, respectively for opening and closing the loading section. Piping 18 will have a suitable rotation joint (not shown) to allow the rotation of the lid.
[0076] Even though the apparatus described in the various embodiments is foreseen for use as a stand alone unit, with the advantage that it can be positioned in a variety of locations without requiring connections to the water supply or the drain for liquids, in some cases it should not be excluded to have cleaning cycles and related draining of liquids like is described in EP 1707270 and the two mentioned applications. In fact, the use of powder achieves savings in energy, water and sanitizing and cleaning liquids, which can be used during limited periodic cycles of cleaning of the machine.
[0077] As shown in FIG. 6 , the apparatus is positioned below a sink unit 81 and comprises the loading section 11 , the grinding unit 12 , the collection container 15 and eventually even the devices for collecting the liquids (not shown). As shown in FIGS. 6 and 7 apparatus A can be positioned in the lowest area under the sink unit 81 and more precisely under one of the sinks 80 . The position of the apparatus A can be to one side with respect to the siphon 82 that is required for connection to drain 83 . The overall height H of the apparatus A is less than 50 centimeters.
[0078] For loading of the waste W in section 11 of FIG. 6 (see arrow C) and emptying of the waste container 15 , the user can extract from the apparatus (see movement represented with arrow F) both the loading section with the grinding section (see the external position of the loading section and the grinding section represented with the dashed line contour 11 ′ and 12 ′, respectively) and the collection container for the waste 15 (see the position of the collection container represented with the dashed line contour 15 ′). The extraction of the members 11 , 12 , 15 and their return to the inside position to start the grinding operation occurs respectively by pulling and pushing on the front handles of the apparatus. In this way members 11 , 12 , 15 move in the directions of arrows F and F′.
[0079] In the section view of FIG. 8 the container for the waste 15 is in contact with the surface 70 ′ of the frame 70 in order to become sealed and thereby avoid bad smell from escaping. Surface 70 ′ is provided with sealing member 71 , which is seated in frame 70 . Frame 70 can be a portion of the structure where passage of ground waste to reach container 15 occurs. Container 15 is maintained in contact with surface 70 ′ by means of locking members 72 (see FIG. 9 ), which can be actuated rapidly, as more fully illustrated in FIG. 9 .
[0080] In FIG. 9 , for reasons of illustration, the front panel of the apparatus has been removed and container 15 is shown in the external position of the apparatus, like is the condition represented by dashed line contour 15 ′ of FIG. 6 . In FIG. 9 , two locking members 72 can be seen on one side of container 15 . Another two locking members are on the opposite side of the container and are not visible in FIG. 9 .
[0081] The locking members 72 are hinged to respective levers 74 , which are in turn hinged to container 15 . Each locking member 72 hooks onto a respective hook 73 positioned on frame 70 . The locking members are hooked onto the hooks and pulled by manually rotating levers 74 around pins where each lever results hinged on container 15 . By rotating the levers in direction 74 ′, the top face of container 15 is pulled against surface 70 ′, and therefore against sealing member 71 to form the sealed joint.
[0082] The foregoing description of specific embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without departing from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
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Apparatus for grinding waste material like kitchen waste foresees a loading section ( 10 ) for loading the waste material, a grinding section ( 12 ) for grinding the waste material, means for collecting ( 15 ) the ground waste, and means ( 20,25,35 ) for dispensing controlled quantities of sanitizing or cleaning powder (P) in the apparatus directly on the waste material present in the loading section, or on the internal surfaces of the apparatus. The powder can also be dispensed on the waste material that has been ground and collected ( 15 ).
The powder (P) that is dispensed influences the biological transformation of the waste to avoid formation of hazardous substances for the health and sources of bad smell. The powder can be dispensed directly or by movement with a flow of air, which is generated for example by a rotor or piston mechanism. There can also be a system that fluidizes the powder to create a flow of air mixed with powder which is then dispensed in the apparatus. The apparatus can have reduced size and can be located under a sink unit.
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DESCRIPTION OF RELATED ART
When interconnecting computers and other devices in a network, it has become desirable to create "virtual local area networks" (VLANs), in which all devices coupled to a VLAN receive all frames or packets which are universally addressed (whether by broadcast, multicast, or some other technique) on that VLAN, and in which all frames or packets which are universally addressed by a device on a VLAN are not distributed to devices outside the VLAN. However, there is more than one type of VLAN transport protocol technology which has been proposed and come to be accepted in the art. For example, VLAN technologies which are now common include LANE (for ATM LAN-Emulation), IEEE Standard 802.10, and various proprietary schemes such as ISL (for cisco Catalyst™ Inter-Switch Links).
One problem which has arisen in the art is that it is desirable to couple devices on a single VLAN even though those devices have been designed or configured for different VLAN transport protocols or technologies. Aspects of this problem are that it is desirable for devices to be on the same VLAN even though they are not physically proximal to each other or cannot be coupled to the same switching device (for example, due to limitations imposed by respective media speed), that it is desirable for devices (or networks comprising those devices) to be configurable so that a device may be moved from one VLAN to another VLAN with ease, and that it is desirable for a device to be coupled to different VLANs at different times or to multiple VLANs at one time.
Accordingly, it would be advantageous to provide a multiple VLAN architecture system, such as one which is capable of operating in a network environment with multiple different VLANs and multiple different VLAN technologies.
The following U.S. Patent(s) may be pertinent:
U.S. Pat. No. 5,394,402, issued Feb. 28, 1995, in the name of Floyd E. Ross, titled "Hub For Segmented Virtual Local Area Network With Shared Media Access".
This patent discloses a hub for a segmented VLAN system. The hub receives packets from one of the devices, called "end stations" which are coupled thereto, and forwards them using a backbone network to other such hubs, for forwarding to other devices coupled to the same VLAN. Essentially, the hub serves to bridge packets among its ports such that packets are bridged only to those other devices which are on the same VLAN.
The pertinence of the related art will also be apparent to those skilled in the art after perusal of this application.
SUMMARY OF THE INVENTION
The invention provides a system in which a single VLAN architecture spans multiple VLAN transport protocols and technologies, including a method and system in which each VLAN may span multiple different VLAN technologies. Each LAN-switch in the system identifies each frame with an identifier, and associates that identifier with particular VLAN identifiers for each type of VLAN architecture. When a frame is bridged or routed from a first type of VLAN to a second type of VLAN, the first VLAN encapsulation is removed and the second VLAN encapsulation is added, with appropriate change in the VLAN identifier for the frame or packet. The identifier may also be implicit for the frame, such as when a particular set of sender's MAC addresses are identified with a particular VLAN.
In a preferred embodiment, individual VLANs, which may span the set of multiple VLAN technologies, may be added, configured or reconfigured, modified, or deleted, using control tools associated with the multiple VLAN architecture system. Individual ports may be associated with particular VLANs, or may be designated "dynamic" so that frames or packets associated with those ports are associated with particular VLANs in response to source or destination addresses or other information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a network having multiple VLANs.
FIG. 2 is a diagram of a set of LAN-switches disposed for coupling messages between multiple VLANs.
FIG. 3 is a diagram showing a relationship between multiple VLANs, management domains, and network administration.
FIG. 4 is a diagram showing message formats for use in a VLAN protocol.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description, a preferred embodiment of the invention is described with regard to preferred process steps and data structures. However, those skilled in the art would recognize, after perusal of this application, that embodiments of the invention may be implemented using a set of general purpose computers operating under program control, and that modification of a set of general purpose computers to implement the process steps and data structures described herein would not require undue invention.
Multiple Vlan Architecture System
FIG. 1 is a diagram of a network having multiple VLANs.
In an interconnected network 100, a set of devices 101 may be coupled to a plurality of physical networks 102. Each network 102 may comprise a local area network (LAN) such as an ethernet LAN, a token ring LAN, an FDDI network, or another LAN architecture. Each network 102 may transmit a set of frames 104 using one of a plurality of media access transmit protocols. Architectures for local area networks and for their media access transmit protocols are known in the art of networking.
The networks 102 are coupled using a set of LAN-switches 103. The LAN-switches 103 forward frames (using a level two protocol) or packets (using a level three protocol) among the networks 102. Each LAN-switch 103 is coupled to one or more networks 102. For example, one of the LAN-switches 103 may be coupled to two or more networks 102. LAN-switches are known in the art of networking.
The devices 101 are associated with a plurality of different VLAN technologies, and therefore may transmit frames using one of a plurality of VLAN transmit protocols. For example, each device 101 may be associated with a VLAN transmit protocol such as ATM LAN Emulation (LANE), IEEE 802.10, cisco Catalyst™ Inter-Switch Links (ISLs), or another VLAN transmit protocol. Each device 101 may be associated with just one VLAN technology, or with a plurality of VLAN technologies.
The devices 101 are assigned to a plurality of VLANs 106, independent of their associated VLAN technologies. Each VLAN 106 need not comprise a single or homogeneous VLAN technology; moreover, each VLAN 106 is not subject to any requirement that all devices 101 on that VLAN 106 are proximate or even coupled using the same LAN or VLAN technology.
Those frames 104 to be transmitted on a particular VLAN segment 108 are identified with a tag 107 referencing that particular VLAN 106. As the frame 104 is forwarded between differing VLAN technologies, the tag 107 uses a tagging technique particular to that VLAN technology. For example, the tag 107 for the same VLAN 106 may be the character string "GR" for LANE, the numeric value `1024` for IEEE 802.10, or the numeric value `10` for ISL.
The LAN-switches 103 are configured to (1) receive frames from a first VLAN associated with a first VLAN transmit protocol and encapsulated using a multiple-VLAN transmit protocol, (2) to remove the encapsulation, (3) to re-encapsulate the frames with a second VLAN transmit protocol, and (4) to transmit the re-encapsulated frames onto a second VLAN.
In alternative embodiments, the frames 104 may have implicit tagging. In this case, those frames 104 which are addressed from a first particular set of MAC addresses (or are otherwise identifiable from their frame headers) are designated as being for a first VLAN segment 108, while those frames 104 which are addressed from a second particular set of MAC addresses are designated as being for a second VLAN segment 108.
As described herein, the LAN-switches 103 may also include the capability to perform layer-3 routing. LAN-switches 103 which include such layer-3 routing may couple a set of frames 104 between virtual LANs (VLANs) as well as physical networks 102, it is possible for such a LAN-switch 103 to be coupled to only a single network 102, and to route the frames 104 found on that network 102 between different VLANs. In that circumstance, the LAN-switch 103 receives the frame 104 from one of the VLANs implemented by the network 102, and transmits the frame 104 onto another one of the VLANs implemented by the network 102. An example of one such LAN-switch 103, sometimes called a "lollypop water " 105, is shown in the figure.
Forwarding Frames Among Multiple VLANs
FIG. 2 is a diagram of a set of LAN-switches disposed for coupling messages between multiple VLANs.
The set of LAN-switches 103 collectively comprises a subnet 200, in which pairs of the LAN-switches 103 are coupled by a set of links 201. Each link 201 comprises a physical network 102, so that a set of frames 104 may be coupled between pairs of LAN-switches 103. Each LAN-switch 103 comprises a set of ports 202 coupling the LAN-switch 103 to one of its links 201, and therefore to another LAN-switch 103.
Each LAN-switch 103 receives packets at each of its ports 202, and recognizes each VLAN 106 which might be received at port 202. When a frame 104 must be forwarded from a first VLAN segment 108 to a second VLAN segment 108, the LAN-switch 103 removes tags 107 (shown in the figure as the numeric value `10`) for a first VLAN segment 108 and replaces them with tags 107 (shown in the figure as the character string value `GR`) for a second VLAN segment 108.
In a preferred embodiment, the LAN-switch 103 identifies the second VLAN segment 108 required for the destination device 101 responsive to the output port 202 to which the frame 104 is routed. The port 202 may be one of three types shown in table 2-1.
TABLE 2-1______________________________________Port Type Treatment______________________________________static Each frame from the port is for a particular VLAN which is statically configured for that port, regard- less of the address or content of that frame.dynamic The port may be assigned to one of a plurality of VLANs, one at a time. Each frame to or from the port is examined and the port is dynamically reassigned to a different VLAN in response to the address or con- tent of that frame. (For example, the port may be dynamically reassigned in response to the MAC address of the sending device, or in response to a layer three address.)trunk The port is assigned to a plurality of VLAN at once. Each frame to or from the port uses an encapsulation or related technique to tag that frame as for a par- ticular VLAN. A VLAN trunk protocol causes each LAN-switch to transmit advertisements regarding, and acquire infor- mation about, VLANs for which that trunk port is con- figured. Thus, a new VLAN need only be configured for one LAN-switch in a management domain, as the VLAN trunk protocol will ultimately propagate that information to all LAN-switches in the management do- main. The VLAN trunk protocol is described in fur- ther detail below.______________________________________
When the LAN-switch 103 receives a frame 104 on a static port 202, it knows that frame 104 must be for the VLAN 106 statically configured for that port 202. When the LAN-switch 103 transmits that frame 104 on another port 202 which is a trunk port 202, it must encapsulate the frame 104 with the appropriate outgoing tag 107 to indicate the VLAN 106.
When the LAN-switch 103 receives a frame 104 on a dynamic port 202, it knows that the frame 104 must be configured according to one of the plurality of VLANs 106 configured for that port 202, responsive to the address or contents (preferably the MAC address) of that frame 104. The LAN-switch 103 identifies the incoming VLAN 106 responsive to the MAC address of the frame 104. When the LAN-switch 103 transmits that frame 104 on another port 202 which is a trunk port 202, it must remove the encapsulate the frame 104 with the appropriate outgoing tag 107 to indicate the VLAN 106.
When the LAN-switch 103 receives a frame 104 on a trunk port 202, it knows that the frame 104 must be encapsulated and that the encapsulated frame may be for one of a plurality of VLANs 106. The LAN-switch 103 identifies the VLAN 106 for the frame 104 responsive to the encapsulation header, and removes the encapsulation. When the LAN-switch 103 transmits that frame 104 on another trunk port 202, it must re-encapsulate that frame 104.
An network administrative workstation 203 is coupled to one LAN-switch 103 or elsewhere, and comprises a processor, program and data memory and mass storage, for executing application programs and for recording information, at least one input device (such as a keyboard or a pointing device such as a mouse) for receiving information from an operator 204, and at least one output device (such as a monitor or printer) for presenting information to the operator 204.
To identify the outgoing tag 107 which corresponds to the incoming tag 107, the LAN-switch 103 maintains a database 205 which is preferably also available at the network administrative workstation 203. The database 205 comprises a table 206; the table 206 comprises a set of rows 207 and a set of columns 208, with an entry 209 at the intersection of each row 207 and each column 208. The table 206 is indexed by a column 208 for a VLAN management ID; there is one row 207 for each VLAN 106 and one column 208 for each VLAN transmit protocol.
In a preferred embodiment, the VLAN management ID comprises a character string, such as "red" or "green". One VLAN management ID, "default", is reserved for an initial VLAN 106. LAN-switches 103 are configured for the "default" VLAN 106 when they are shipped from the factory. In a preferred embodiment, the VLAN management ID comprises an ASCII character string of eight characters or less.
In a preferred embodiment, the table 206 comprises one column 208 for LANE, one column 208 for IEEE 802.10, and one column 208 for ISL. Each entry 209 comprises a tag 107 for the VLAN corresponding to its row 207 and the VLAN transmit protocol corresponding to its column 208. The data for each entry 209 has a data type which depends on the particular VLAN technology, such as numeric data, ASCII character data, or other data.
In a preferred embodiment, the ISL tag 107 for the "default" VLAN 106 is `1`. For IEEE 802.10, frames 104 for the "default" VLAN 106 may be transmitted as native frames without IEEE 802.10 encapsulation.
In a preferred embodiment, the database 205 also comprises information regarding properties associated with each VLAN 106 (such as, for example, whether the VLAN 106 has had its operation suspended).
In alternative embodiments, the database 205 may be made available at other locations. For example, the database 205 may be recorded and updated separately at each LAN-switch 103, at a particular LAN-switch 103, or at a particular non-routing device 101.
Manangement Domains and Network Administration
FIG. 3 is a diagram showing a relationship between multiple VLANs, management domains, and network administration.
The network administrative workstation 203 controls a set of management domains 300, each of which comprises one or more VLANs 106. Each VLAN 106 comprises one or more devices 101 on one or more networks 102 in the interconnected network 100.
Each VLAN 106 must have a unique name within its management domain 300.
When two management domains 300 are coupled via a trunk port 202, the default behavior (prior to any additional configuration) is that no frames 104 are forwarded between the two management domains 300. However, the respective ports 202 may be configured using the network administrative workstation 203 to forward frames 104 for specific VLANs 106.
When two management domains 300 are coupled via a nontrunk port 202 (thus, via a static port 202 or a dynamic port 202), the respective ports 202 may be configured using the network administrative workstation 203 to forward frames 104 for specific VLANs 106.
When frames 104 are transmitted across a trunk port 202 between a first management domain 300 and a second management domain 300, the LAN-switch 103 must have a mapping between the source VLAN 106 in the first management domain 300 and the destination VLAN 106 in the second management domain 300.
Each LAN-switch 103 maintains a list of VLANs 106 which are valid in its management domain 300. This list is associated at each LAN-switch 103 with a configuration revision number; the configuration revision number is updated whenever a change is made to the configuration for that managment domain 300. Thus, a LAN-switch 103 can compare its configuration revision number with the new configuration to determine which is more recent.
When they are initially shipped from the factory, LAN-switches 103 are configured in a "no-management-domain" state. In this state the LAN-switch 103 does not belong to any particular managment domain 300 and will update its database to learn about new VLANs 106 from all VLAN trunk protocol advertisements it receives. When a LAN-switch 103 is configured for a particular managment domain 300, it will ignore advertisements from different managment domains 300 and it will check advertisements from the same managment domain 300 for consistency.
When a LAN-switch 103 learns about a VLAN 106, it will received frames 104 from that VLAN 106 on any trunk port 202, and will forward those frames 104 to all of its other trunk ports 202 (if any). This behavior may be altered by reconfiguring the LAN-switch 103 using the network administration workstation 203 to disable one or more VLANs 106 for a particular trunk port 202.
Multiple VLAN Network Administration
The operator 204 at the network administrative workstation 203 may alter the database 205 and cause those alterations to be propagated to the LAN-switches 103. Table 3-1 shows the changes which the operator 204 at the network administrative workstation 203 may make.
TABLE 3-1______________________________________Change Effect______________________________________create a A new VLAN is created. A record is created for theVLAN new VLAN; a new VLAN management ID is created; en- tries are made for the new VLAN for each VLAN tech- nologydelete a An existing VLAN is removed from the configurationVLAN for the managment domain. The deleted VLAN's entries in the database at the network administration work- station are purged and any ports configured for the deleted VLAN are automatically disabled. In an alternative embodiment, the deleted VLAN is only purged from the database after all ports config- ured for the deleted VLAN are reconfigured for an- other VLAN. The "default" VLAN cannot be deleted.suspend a An existing VLAN has its operation suspended. AllVLAN traffic for the suspended VLAN is turned off for the duration of the suspension. (This function might be useful, for example, if traffic for the suspended VLAN was disrupting the network.) All ports config- ured for the suspended VLAN are disabled for the du- ration of the suspension. The "default" VLAN cannot be suspended.resume a A suspended VLAN has its suspension terminated. AllVLAN ports for the resumed VLAN are re-enabled and traffic is allowed to flow for the resumed VLAN.______________________________________
Those skilled in the art will recognize, after perusal of this application, that other and further management functions would not require undue experimentation, and are within the scope and spirit of the invention.
VLAN Protocols and Message Formats
FIG. 4 is a diagram showing message formats for use in VLAN protocols.
VLAN Trunk Protocol
Each LAN-switch 103 transmits advertisements regarding all VLANs 106 about which it knows, and possibly other information global to the management domain 300. Advertisements are transmitted via the "default" VLAN 106; thus, only one advertisement is transmitted for each trunk port 202. Advertisements are transmitted as multicast frames 104 but not forwarded using normal bridging techniques.
Each LAN-switch 103 maintains a configuration revision number for each managment domain 300 for which it is configured. The configuration revision number is an unsigned 32 bit value, which is initially set to zero and is incremented by one for each modification or reconfiguration at the LAN-switch 103 until the maximum value of 4,294,967,295 (hexadecimal `FFFF FFFF`) is reached, at which point the configuration revision number is wrapped around back to zero.
When a LAN-switch 103 receives an advertisement and it is not configured for any managment domain 300, it updates its database 205 from that advertisement. When a LAN-switch 103 receives an advertisement and it is configured for one or more particular managment domains 300, it authenticates that advertisement using its current configuration revision number for the appropriate managment domain 300. If the advertisement is authentic and its configuration revision number exceeds the LAN-switch's current configuration revision number, the LAN-switch 103 updates its database 205 from that advertisement; otherwise the LAN-switch 103 ignores the advertisement.
The configuration revision number A is deemed to be less than the configuration revision number B if and only if
((A<B and (B-A)<2,147,483,648)
or (A>B and (A-B)>2,147,483,648))
The types of advertisement messages are shown in table 4-1.
TABLE 4-1______________________________________Port Type Treatment______________________________________Advert- This message requests that an advertisement be sent.RequestSummary- This message provides the management domain, configu-Advert ration revision number, and checksum for the adver- tisement. The Summary-Advert message is followed by zero or more Subset-Advert messages, as appropriate.Subset- This message comprises all advertised information forAdvert one or more VLANS. Each Subset-Advert message is la- belled with a sequence number in case more than one Subset-Advert message is sent.______________________________________
The Advert-Request message 400 comprises a VLAN trunk protocol version number 401 (1 byte, which is always `1`), a type of message code 402 (1 byte, which is always `3` for the Advert-Request message 400), a reserved byte 403, a mangement domain name 404 (variable length, but always a multiple of 4 bytes), a length value 405 (1 byte) for the mangement domain name 404, and a start value 406 (2 bytes).
The Summary-Advert message 410 comprises the VLAN trunk protocol version number 401, the type of message code 402 (which is always `1` for the Summary-Advert message 410), the mangement domain name 404 (variable length, but always a multiple of 4 bytes), a length value 405 (1 byte) for the mangement domain name 404, a configuration revision number 411 (4 bytes), an MD5 digest value 412 (4 bytes), and a followers value 413 (1 byte).
The Subset-Advert message 420 comprises the VLAN trunk protocol version number 401, the type of message code 402 (which is always `2` for the Subset-Advert message 420), a reserved byte 403, the configuration revision number 411, a sequence number 421 (1 byte), and a sequence of VLAN blocks 430.
Each VLAN block 430 comprises a status value 431 (1 byte), a VLAN type value 432 (1 byte), a VLAN name 433 (variable length, but always a multiple of 4 bytes), a length value 434 (1 byte) for the VLAN name 433, an ISL VLAN identifier 435 (2 bytes), an IEEE 802.10 index value 438, and a maximum frame size value 439.
The start value 406 is used in the event that the LAN-switch 103 does not desire all VLANs 106 to be advertised to it. In the actual advertisement, the Subset-Advert messages 420 are ordered by ISL VLAN identifier 435. The start value 406 indicates from which ISL VLAN identifier 435 to start; all VLANs 106 which precede the start value 406 are not advertised. If the start value 406 is zero, all VLANs 106 are advertised.
Advertisements are authenticated; learning only occurs from authentic advertisements. Each advertisement comprises a checksum, preferably the MD5 digest value 412, which is computed using a one-way cryptographic hash function (the MD5 digest function) of the concatenation of (1) the Summary-Advert message 410 with the followers value 413 replaced with a zero value, (2) the VLAN blocks 430 ordered by ISL VLAN identifier 435, and (3) a "secret value". The default secret value is all zeros, thus providing non-secure but immediately compatible operation. The secret value may be configured for each LAN-switch 103 using the network administrative workstation 203, thus providing secure operation. Since each advertisement comprises a new configuration revision number 411, the MD5 digest value 412 cannot be repeated until the configuration revision number 411 is itself repeated.
The followers value 413 indicates how many Subset-Advert messages 420 follow the Summary-Advert message 410. The number of Subset-Advert messages 420 which follow the Summary-Advert message 410 are shown in table 4-2.
TABLE 4-2______________________________________Reason for Sending Advertisement Number of Followers______________________________________Neither this LAN-switch or any zeroother LAN-switch has recently(within the timeout period) sentan advertisement.A configuration change has been the minimum number required tomade. contain all information on ex- actly those VLANs which have changed, ordered by ISL VLAN identifierAn Advert-Request message for the minimum number required toinformation for all VLANs was contain all information on allreceived. VLANs, ordered by ISL VLAN iden- tifierAn Advert-Request message for the minimum number required toinformation about a subset of contain all information on allall VLANS was received. VLANs except those which were not requested, ordered by ISL VLAN identifier______________________________________
The VLAN type value 432 indicates what type the VLAN 106 is: ethernet or IEEE 802.3, token ring or IEEE 802.5, or FDDI.
The maximum frame size value 439 indicates the maximum frame size for that particular VLAN 106.
An Advert-Request message 400 is sent in the following cases:
when the LAN-switch 103 is rebooted.
when the LAN-switch 103 receives a Subset-Advert message 420 having a configuration revision number 411 higher than the LAN-switch's own configuration revision number 411.
when the LAN-switch 103 receives a Summary-Advert message 410 having a configuration revision number 411 higher than the LAN-switch's own configuration revision number 411, and followed by zero Subset-Advert messages 420.
when the LAN-switch 103 does not receive the expected number of Subset-Advert messages 420 within a short period after receiving a Summary-Advert message 410 having a configuration revision number 411 higher than the LAN-switch's own configuration revision number 411. In this case, the Advert-Request message 400 is set to request only the missing Subset-Advert messages 420, by setting the start value 406 to one more than the highest ISL VLAN identifier 435 received.
when the LAN-switch 103 receives a Summary-Advert message 410 having a configuration revision number 411 more than one value higher than the LAN-switch's own configuration revision number 411.
An advertisement, comprising a Summary-Advert message 410 and zero or more Subset-Advert messages 420, is sent in the following cases:
immediately after its configuration revision number is modified (thus, immediately after any configuration change);
periodically on any trunk port 202 for which it has not sent an advertisement or received an advertisement matching its own, for a configurable timeout period, preferably about five minutes. The actual time for sending advertisements is jittred (modified by a small random or pseudorandom value) to avoid syncrhonization effects. Periodic advertisements can be disabled using the network administrative workstation 203.
when a request for an advertisement is received. In this case, the timeout period is truncated to a small random or pseudorandom value.
In a preferred embodiment, the timeout for sending an advertisement is between about 2 minutes and about 10 minutes. Whenever this timeout is started, a pseudorandom value of less than about 1 second is added to it. When a consistent advertisement is received, the timeout is restarted without sending any advertisement. When an Advert-Request message 400 is received, the timeout is truncated to the value of the most recent pseudorandom value.
Those skilled in the art will recognize, after perusal of this application, that the VLAN trunk protocol may be used to distribute other and further types of information, that such activity would not require undue experimentation, and that such activity is within the scope and spirit of the invention. For example, such other and further types of information could include the following:
port configuration information--whether a particular port 202 is a static port 202, dynamic port 202, or a trunk port 202; or
dynamic assignment configuration information--either (1) which VLAN 106 a dynamic port 202 is associated with, or (2) a mapping between a layer three protcol address space, or a subspace thereof, and which VLAN 106 a dynamic port 202 should be associated with.
VCS Protocol
A VLAN configuration server comprises local information about VLANs 106, including port configuration information and dynamic assignment configuration information. In a preferred embodiment, the VLAN configuration server is available at the network administrative workstation 203, but in alternative embodiments, may be a separate device 101 or may be distributed over several LAN-switches 103 or other devices 101.
To configure its ports 202, each LAN-switch 103 sends a message to the VCS to request configuration information. If the LAN-switch 103 is coupled to a ATM network 102, it also attempts, for each VLAN 106 it knows about, to join the LANE emulated-LAN (ELAN) having the same name.
For static ports 202, the LAN-switch 103 receives configuration information specifying with which VLAN 106 the port 202 is associated.
For dynamic ports 202, the LAN-switch 103 receives configuration information specifying a mapping to VLANs 106 for MAC addresses for the sending devices 101 for frames 104.
The message requesting configuration information is sent directly to the VCS if the LAN-switch 103 is not coupled to a ATM network 102. Otherwise, the message is encapsulated using the LANE protocol and sent to a LANE configuration server (LECS).
If the VCS (or LECS) responds for a port 202 with a VLAN name (or ELAN name) which is known to the LAN-switch 103, the port 202 is assigned to the VLAN 106 with that name.
If the VCS (or LECS) responds for a port 202 with a refusal, that port 202 is disabled.
If the VCS (or LECS) responds for a port 202 with a VLAN name (or ELAN name) which is not known to the LAN-switch 103, or if the VCS (or LECS) does not respond after a number of retries, or if the VCS (or LECS) cannot be reached, the LAN-switch 103 retries the request at periodic intervals.
However, if the LAN-switch 103 has local configuration information which maps a source MAC addresses to VLANs 106 for a dynamic port 202, it uses that local configuration information to reassign the dynamic port 202 in response to source MAC addresses.
Alternative Embodiments
Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.
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A system in which a single VLAN architecture spans multiple VLAN transport protocols and technologies, including a method and system in which multiple different VLANs may be combined in a single enterprise network. Each LAN-switch in the sytem identifies each frame with an identifier, and associates that identifier with particular VLAN identifiers for each type of VLAN technology. When a frame is bridged or routed from a first type of VLAN to a second type of VLAN, the first VLAN encapsulation is removed and the second VLAN encapsulation is added, with appropriate change in the VLAN identifier for the frame or packet. The identifier may also be implicit for the frame, such as when a particular set of sender's MAC addresses are identified with a particular VLAN. Individual VLANs, of whatever architecture, may be added, configured or reconfigured, modified, or deleted, using control tools associated with the multiple VLAN architecture system. Individual ports may be associated with particular VLANs, or may be designated "dynamic" so that frames or packets associated with those ports are associated with particular VLANs in response to source or destination addresses or other information.
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This is a continuation of application Ser. No. 07/905,240, filed Jun. 26, 1992, now abandoned.
FIELD OF THE INVENTION
The invention relates to atomizing nozzles commonly used for, but not limited to, hand held sprayers such as so-called aerosols and pump type atomisers, intended for the application of liquid household, cosmetic and pharmaceutical products.
BACKGROUND OF THE INVENTION
Aerosol type sprayers are used throughout the world for dispensing a wide range of products, for example hair lacquer, furniture polish, cleaners, paint, insect killers and medicaments. Until recently, chlorofluorocarbons (CFC's) were the most common of the propellant gases used in aerosols because they are inert, miscible with a wide range of products, are easily liquefied under low pressures, give a substantially constant product flow-rate, and can produce sprays of droplets having mean diameters in the range of 3 to over 100 micrometers. However, in the 1970's it was confirmed that CFC's were probably responsible for depleting the Earth's protective ozone layer, and in 1987, most countries signed the Montreal Protocol to phase out the use of CFC's. Alternative propellants were then introduced--for example liquefied hydrocarbon gases such as butane, and carbon dioxide, which is dissolved in the product, --but these are flammable or otherwise harmful to the environment, or react with the product, and these propellant gases are gradually being phased out. There has been much development of aerosols powered by compressed gas (e.g. nitrogen, air), and manually operated pump atomizers, and for the majority of applications the performance of such sprayers is adequate.
The main drawback of these non-CFC sprayers is that the smallest sized droplet that can be produced is about 40 micrometers diameter, and despite considerable development of so-called mechanical breakup nozzles, the use of high pressure (circa 15 bars) pumps, and low viscosity/surface tension product formulations, 40 micrometers appears to be the lower limit achievable with prior art methods and devices.
There are aerosol generators used for research and hospital applications, such as ultrasonic nebulisers and spinning disc generators, but neither is suitable for portable, convenient atomizers.
It is also possible to force liquid at high pressure through a very small hole (5-10 micrometers diameter) to produce droplets of about 5 micrometers diameter, but these methods are unsuitable or uneconomic for large scale manufacture, mainly because of the difficulty in making very small holes in a suitable material, and, to prevent blockage of the hole, the need for exceptional cleanliness in the manufacture of the parts, together with ultrafiltration of the fluid to be sprayed.
For veterinary and some human vaccination applications, high pressure (125-500 bars) spring or gas operated pumps (so-called needle-less injectors) are in common use to inject a jet of drug through the skin ("intra-dermal injection") without the use of needles, and attachments are available to convert the jet to a spray for administering drugs to the nasal passages of large animals such as swine. However, the smallest droplet size obtainable is in the order of 40 micrometers, and the range of applications for these injectors is limited.
Compressed air atomizers such as air brushes and commercial paint sprayers consume large quantities of air, and to obtain droplets of 5 micrometers with water for example, a gas to liquid ratio of over 30,000:1 is required, which is impractical for convenient, portable sprayers.
Nevertheless, there are some applications that rely on a smaller droplet size for maximum efficacy: space sprays such as flying insect killers should contain droplets ideally in the range of 20-30 micrometers diameter to ensure a long flotation time in the air, and for metered dose inhalers (MDI's) used for treating certain respiratory disorders it is essential that the aerodynamic particle size should be less than 15 micrometers, preferably less than 5 micrometers, so that the droplets are able to penetrate and deposit in the tracheobronchial and alveolar regions of the lung. For a spray composed of droplets with a range of sizes, more than 5% by weight of the droplets should have an aerodynamic size less than 6.4 micrometers, preferably more than 20 by weight of the particles have an aerodynamic size less than 6.4 micrometers.
Inhalers may also be designed to deliver drugs to the alveolar sacs of the lung to provide a route for adsorption into the blood stream of drugs that are poorly adsorbed from the alimentary tract. To reach the alveoli it is essential that the aerodynamic size of the particles is less than 10 micrometers, preferably 0.5-5 micrometers.
Many of the drugs used in the treatment of respiratory disorders are insoluble in vehicles such as water and are dispensed as suspensions. The drugs are produced in a respirable size of 1-5 micrometers. Particles of this size tend to block the very small holes (5-10 micrometers) used by known devices to generate droplets of about 5 micrometers diameter.
SUMMARY OF THE INVENTION
The present invention aims to provide a design of atomizing nozzle which is capable, inter alia, of being used to give a nozzle which will produce a spray of droplets of a size suitable for inhalation, without the use of liquefied gas propellants. However, the present invention is believed to be capable of being used to give a nozzle which will produce a spray of droplets having a mean diameter anywhere in the range of from 0.5 to over 100 micrometers.
According to the present invention there is provided an atomizing nozzle for producing a spray of droplets form a liquid passing through the nozzle under pressure, which nozzle comprises means defining an orifice; a closure member for the orifice, the orifice-defining means and closure member being relatively movable with respect to one another between a first position in which the closure member cooperates with the orifice to close it and a second position in which the closure member is spaced from the orifice-defining means to define a gap therebetween; and a stop for limiting relative movement between the orifice-defining means and the closure member to ensure that the width of the gap cannot exceed that which will produce a fine spray.
Although the invention is intended mainly for metered dose inhalers and manually operated pumps, it may also be applied in other applications requiring small droplets, for example in certain industrial processes.
In one embodiment of the present invention the nozzle has a circular orifice which is sealingly closed by a ball urged by a spring. Under the action of liquid under pressure, the ball is displaced from the orifice by an amount determined by the stop, which may be fixed or adjustable, and the fluid flows through the gap thus formed and emerges as a thin circular sheet. As the sheet of liquid expands it becomes thinner, and the outer edge breaks into droplets, the diameters of which are determined by the size of the gap, the pressure of liquid, and the physical properties of the liquid. When the pressure in the liquid is reduced below a predetermined level, the ball is urged by the spring sealingly onto the orifice, thus preventing ingress of dirt, evaporation of the product, and atmospheric contamination.
In another embodiment of the invention, the liquid to be sprayed is caused to flow past a spherical surface and through a gap formed between that surface and a circumambient hole in a plate. The plate is preferably made of a spring material and located so that it is in sealing contact with the spherical surface as a normally closed valve. Under the action of liquid under pressure, the plate is forced away from the spherical surface by an amount determined by the stop, which may be fixed or adjustable, and the fluid flows through the gap thus formed to emerge as a thin circular sheet. As the sheet of liquid expands, it becomes thinner, and the outer edge breaks into droplets, the diameter of which are determined by the size of the gap, the pressure of liquid and the physical properties of the liquid. When the pressure in the liquid is reduced below a predetermined level, the spring plate returns to its original position to seal against the spherical surface, thus preventing ingress of dirt, evaporation of the remaining product, and atmospheric contamination.
Whilst reference has been made above to the use of a ball or spherical surface in co-operation with a circular orifice in a plate or nozzle, other shapes could be used, for example, a conical surface co-operating with a circular hole. The precise profile of the surface and hole will be determined in part by the spray pattern required, and the present invention provides for all combinations of surfaces and holes, but it is preferred that at least one of the components has a varying cross section so that the gap between them is opened or closed as a result of relative movement. Since the stop ensures that the gap is of substantially constant size when the components are fully apart, an even spray results from the passage of fluid throughout the length of the gap. The width of the gap is preferably of the order of 5 micrometers. The ratio of the length of the gap L to the width of the gap D is preferably not more than 1 and more preferably not more than 0.5. By the "length" of the gap we mean the distance which the liquid has to travel in order to pass through the gap.
The surface finish of the co-operating components in the region of the gap should be sufficiently fine so as not to adversely affect the droplet size and pattern of the spray: for example, a groove in one component would cause a stream of liquid to issue therefrom, which would probably not have the required characteristics, and could lower the pressure in the liquid sufficiently to adversely affect the quality of spray emerging from the remainder of the gap. The finish should be sufficiently fine to ensure efficient sealing between the components when in the closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 illustrates the principle of the invention and is a cross sectional view of the basic elements in their normal, non-pressurised relationship.
FIG. 2 is a similar view to FIG. 1, and shows the elements in the operating position.
FIGS. 3 and 4 show a modified form of the embodiment of FIGS. 1 and 2.
FIGS. 5 and 6 show an alternative embodiment of the principle of the invention, in closed and open position respectively.
FIG. 7 is an enlarged part section showing the conjunction if the principal components illustrated in FIGS. 5 and 6.
FIG. 8 shows a section through a modified version of the spring plate used in the embodiment FIGS. 5 and 6.
FIGS. 9 and 10 show a modified form of the embodiment of FIGS. 5 and 6.
FIGS. 11 and 12 show a spray device for use as an inhaler, incorporating a nozzle according to the present invention.
FIG. 13 shows the nozzle used in FIGS. 11 and 12, on a larger scale.
FIG. 14 shows another form of spray device incorporating; the nozzle according to the invention.
FIG. 15 shows an embodiment of the nozzle having a gap of adjustable size.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, ball 1 is resiliently urged by a compression spring 6 into a position in which it is sealingly located on the circular orifice 3 of nozzle 2. Stop means 5 is located on the longitudinal axis of the ball and orifice, and has a gap 8 between the face 9 of the stop means 5 and the surface of ball 1. Nozzle 2 is in hydraulic communication with a dispensing means (not shown) and contains liquid 7 which is to be sprayed.
Referring now to FIG. 2, which illustrates the same components as in FIG. 1, pressure has been applied to the liquid 7 by the dispensing means, and ball 1 is lifted from the circular orifice 3 against the force of spring 6 until it stops against the face 9 of stop means 5. Thus the ball 1 has moved by an amount controlled by the gap 8 to form a gap 10, the size of which is less than gap 8 by an amount determined by the ratio of the diameters of the ball 1 and circular orifice 3. The liquid 7 issues through the gap 10 as a circular sheet of thickness initially determined by the size of gap 10. As the liquid sheet expands it becomes thinner, until the surface tension of the liquid is unable to maintain homogeneity of the sheet, and the periphery of the sheet breaks into small droplets. The size of the droplets is controlled by the dimension of the gap 10 and the velocity of the liquid, which in turn depends on the pressure generated in the dispenser. A smaller gap 10 will generally produce smaller droplets, provided that the pressure in the liquid is sufficiently high to overcome the viscous drag created by the small gap, and accelerate the liquid to form a thin sheet. (If the pressure is too low, the liquid will merely ooze from the gap).
When the pressure in the liquid 7 ceases, the ball 1 is returned to sealing contact with orifice 3 by spring 6. It is preferable that the contact line between the ball 1 and orifice 3 is very thin, which may be facilitated by chamfering the nozzle as at 4, so as to leave a knife edge. This may have the additional effect of allowing a wider spray angle Z than possible with a square-edged orifice. The orifice 3 has a chamfered peripheral surface with the direction of chamfering being such as to reduce the length of the gap between the ball 1 (closure member) and the nozzle 2 (orifice-defining means).
FIGS. 3 and 4 show a modification in which the stop means 5 is replaced by an alternative stop means 5a which has a recess 5b within which the spring 6 is housed. When the nozzle goes from the closed position shown in FIG. 3 to the open position shown in FIG. 4, the ball 1 seats itself in the open end of the recess. The guidance which this provides ensures that the ball is correctly aligned with respect to the end of the conduit 2, with a uniform annular gap between the orifice 3 and the ball. The spray produced is thus substantially uniform both in distribution around the gap and in droplet size.
An alternative embodiment is shown in FIGS. 5 and 6. In this case, FIG. 5 shows a spherical surface 20 which is located at the outer edge of the discharge conduit 21 containing the liquid to be sprayed 22. A spring plate 24 having a circular orifice 25 is held against the spherical surface 20 so that the circular orifice 25 makes sealing contact with the spherical surface 20, and the outer edge of the spring plate 24 is in sealing contact with the abutment face 26 of conduit 21, thus preventing the passage of liquid 22. A plate 27 having a circular hole 29 is assembled on to the outer face of spring plate 24 so that the hole 29 is co-axial with orifice 25. A step or recess 30 in plate 27 provides a gap 28 between the spring plate 24 and plate 27, the assembly of the two plates being held in sealing contact with the abutment 26 by retaining member 33, which may be a crimped-on ring as shown.
Referring to FIG. 6, the liquid 22 is pressurised by the dispensing means (not shown), and forces plate 24 away from the spherical surface 20, against the inherent bias provided by the fact that the plate 24 is a spring plate, to create the gap 32 between the circular orifice 25 and spherical surface 20. The size of the gap 32 is determined by the size of the gap 28 and by the diameter of the hole 29 in the plate 27, which, between them, determine the extent to which the spring plate 24 can flex. The liquid issues from the gap 32 as a thin circular sheet, the outer edge of which breaks into droplets as previously described. The edge of the circular orifice 25 in spring plate 24 may have a chamfer 40 as shown in FIG. 7, which may permit a wider spray angle than possible with a square-edged orifice. The spring plate 24 may have corrugations 41 co-axial with the orifice 25 as shown in FIG. 8, which will facilitate the flexing of the spring plate. When the pressure is removed from the liquid 22, the spring plate 24 returns to sealing contact with the spherical surface 20.
In FIGS. 5 and 6 the spherical surface 20 is shown diagrammatically as being at the end of a rod, and means (not shown) would be required to support the rod with respect to the fluid discharge conduit 21. FIGS. 9 and 10 show a modified embodiment in which there is a spherical surface 20a formed on a disc 50 which is secured to, or integral witty, the inner wall of the conduit 21. The disc 50 is provided with at least one port 51 through which liquid can pass from the interior of the conduit 21 to the region immediately below the plate 24.
FIGS. 11 to 13 show a spray device incorporating an atomizing nozzle according to the present invention. It is intended for use as an inhalation device. It comprises a reservoir 60 of liquid 61. The liquid 61 may, for example, consist of an aqueous suspension of a medicament suitable for treatment of a condition such as asthma. The lower end of the reservoir is defined by a piston 62 which is longitudinally slidable within the reservoir. Beneath the piston is a stopper 63 which has at least one orifice 64 therein to permit air to enter the space beneath the piston.
The upper end of the reservoir has a neck portion 65 to which a closure member 66 is secured. A portion 67 of the closure member extends within the neck, and an O-ring seal 68 provides a seal between the neck portion 65 and the portion 67. The closure member 66 has a passage 69 therethrough and a tube 70 is secured in the upper portion of this passage. The lower portion of the passage defines an orifice 71, above which is a tapered portion defining a seat for a check valve ball 72. The ball is urged against the seat by a compression spring 73.
An outlet member 74 is mounted on the closure member 66 so as to be movable with respect thereto. The outlet member 74 comprises a generally cylindrical part 75 the lower end of which engages over the closure member 66. The part 75 is prevented from separating from the closure member 66 by interengaging flanges 76 and 77 thereon. The outlet member 74 further comprises an outlet spout 78 through which a user can inhale through his or her mouth. In the case of an inhaler for nasal use, the spout 78 would be replaced by an appropriate nasal outlet.
In the region of the junction between the cylindrical part 75 and the outlet 78, the outlet member 74 has an inwardly extending wall 79 which serves to retain an atomizing arrangement 80. This includes a block 81 which has a hollow lower portion 82 which surrounds the upper end of the tube 70 and which is free to enter a cavity 83 in the upper end of the closure member 66. The hollow portion 82 has an outwardly extending flange 84 at its upper end, and a compression spring 85 is mounted between the flange and the closure member 66.
The interior of the hollow portion 82 communicates via a passage 86 with an atomizing nozzle 90 according to the invention. This is shown on a larger scale in FIG. 13. As can be seen there, it corresponds substantially to what is shown in FIGS. 9 and 10, and comprises a spring plate 91 which cooperates with a spherical surface 92 formed on a disc 93. The disc 93 is provided with at least one port 94 therethrough.
In operation, the user places his or her mouth over the spoilt 78 and squeezes the reservoir 60 and outlet member 74 together against the force of the compression spring 85 to bring the device into the position shown in FIG. 12. During this operation, the ball 72 prevents liquid leaving the reservoir 60 through the orifice 71, and the tube 70 acts as a piston to expel part of the liquid above the ball through the nozzle 90 where it forms an atomised spray. The quantity of liquid expelled in this way constitutes a metered dose, metering being effected by the stroke of the piston. The user inhales this spray. When the user ceases to hold the reservoir 60 and outlet member 74 together, the spring 85 forces them apart. This creates a suction effect within the tube 70 which draws the ball 72 away from its seat and permits liquid to pass from the reservoir through the orifice 71 to replenish what has just been dispensed through the nozzle 90. As the volume of liquid within the reservoir is reduced, the piston 62 slides upwardly under the force of the atmospheric pressure below it, air reaching the underside of the piston through the port 64.
FIG. 14, shows another embodiment of spray device. The figure shows the device in the discharge position. In this embodiment, a valve of similar design to that used as the atomizing nozzle is used also as a non-return inlet valve. FIG. 14 shows an actuator 101 sealingly located on a hollow stem 104 which is integral with a hollow piston 107. Piston 107 is slidingly located within the cylinder 115, the cylinder being formed as the inner part of a pump body 108. The body is retained by a snap fit or other convenient method of retention in a closure 105, a gasket 106 providing a seal between the stem 104 and the closure 105. Gasket 106 is free to flex with axial displacement of the piston and stem, whilst maintaining a seal. A plurality of cantilever springs 109, formed integrally with piston 107, urges the piston in an outward direction by reacting against a conical surface 110 formed in the lower part of the pump body 108. The piston is prevented from coming out of the pump body 108 by an abutment 116 closing on to the gasket 106 which is supported by the inside of the closure 105.
The lower end of the pump body 108 contains a spherical surface 111. A flexible diaphragm 112 with a circular hole therein is sealingly located in the pump body 108 so that the edge of the hole is in sealing engagement with the spherical surface 111. The combination of diaphragm 112 and surface 111 acts as a normally closed non-return valve 120. The extreme lower part of the pump body 108 terminates in a diameter adapted to sealingly retain a dip tube 113. The conduit defined by the dip tube 113 and extreme lower part of the pump body 108 is in communication with an annulus 119 formed between the spherical surface 111 and the diaphragm 112 via one or more ports 117. The actuator 101 has a spherical surface 103, and a flexible diaphragm 102 with a circular hole therein, the edge of which hole is in sealing engagement with the spherical surface 103. The diaphragm 102 is sealingly located by a snap fit or other convenient method within the actuator 101, and the combination of diaphragm 102 and surface 103 acts as a combined non-return valve and atomizing nozzle 121. The hollow stem 104 is in communication with annulus 114 via a port 118.
In operation, the actuator is depressed and allowed to return several times to prime the pump, the valves 120 and 121 cooperating to draw liquid from a reservoir (not shown) and to discharge the liquid from the atomizing nozzle.
FIG. 15 shows an atomizing nozzle in which, unlike those described so far, a means is provided for enabling the gap through which the liquid passes to be adjusted. The nozzle comprises a body 201 which has a threaded exterior to receive a threaded cap 202. The cap may be adjusted to alter a gap 203 formed between a face 204 of the cap and a flexible diaphragm 205. In this way the discharge characteristics may be readily adjusted; for example a spray may be adjusted from a fine to a coarse droplet size.
The description "liquid" used in this specification includes solutions, suspensions and emulsions.
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A method and device are described for atomising liquids, in which the liquid is forced through an annular gap formed between a spherical or conical surface and a circumambient hole in a plate, which components may be displaced relative to one another to control the flow of liquid through the gap. The size of the gap is controlled by a stop.
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This application is a divisional of application Ser. No. 08/235,513, filed on Apr. 29, 1994 now U. S. Pat. No. 5,487,284, the entire contents of which are hereby incorported by reference.
BACKGROUND OF THE INVENTION
The present invention relates to washing machine and move particularly to a washing machine having punch-washing function to reduce the damage of washing article caused by mutual rubbing between the washing article and the pulsator of the washer during washing cycle, and to prevent the wash articles from being entangled with each other, by using up-and-down water flow or non-symmetrical heart-shaped water flow which is generated by the rotation of the pulsator so as to improve the washing effect.
Up to now, many attempts have been made to change the shapes and structures of the pulsator of the washing machines in various forms, for example, bar type, disc type and agitator type, for the purpose of improving the washing effect or preventing the washing articles from being entangled with each other.
FIG. 1 illustrates in detail one of the conventional disc type pulsator 10, which comprises a fixing part 11 formed at the center of the lower end portion thereof a protrusion 12 upwardly projected from the center of the upper end with predetermined height, and smoothly curved blades 13 extending from the central portion to the outer periphery.
This type of pulsator 10, as shown in FIG. 2, is mounted in the inside of a wash tub 20 as to be rotated by a driving motor 30. When the power is on, it rotates back and forth and further blades 13 thereof create the water flow indicated by the arrow in FIG. 2. In addition, the washing articles are being laundered by following aforementioned water flow in the wash tub 20.
However, in a washing machine provided with this pulsator 10, the washing articles being gathered to the central portion of the pulsator 10 and located only at the bottom of the wash tub 20 due to water flows towards the central portion of the pulsator while the pulsator is continued to rotate. Therefore, there is a problem that the washing articles are rubbed with the blades 13 of the pulsator 10 and damaged or even torn by it. In addition, the washing articles are being entangled with each other according to the directional change of the rotation of the pulsator, and thus such pulsator has a problem in that it is impossible to expect a high washing effect due to the entanglement of the washing articles and necessary to disentangle the washing articles after dehydrating.
SUMMARY OF THE INVENTION
It is an object of the present to provide a new type pulsator having an elevating member adapted to push up the washing articles by up-and-down motion during washing cycle, wherein the elevating member is formed at the central portion of the pulsator and repeatedly moves upwards and downwards repeatedly along a spiral groove engraved on the outer surface of a rotating member.
It is another object of the present invention to provide a pulsator in which spring means is provided in the elevating member of the pulsator so as to generate up-and-down water flow smoothly in the wash tub.
It is further another object of the present invention to provide a pulsator which are provided with an elevating member oscillating vertically by the rotation of a rotating shaft and a head swingably fixed to the upper end of said elevating member so that washing operation is carried out without entanglement of the washing articles.
It is further another object of the invention to facilitate the creation of non-symmetrical water flow in the wash tub so as to improve the washing power of the washer.
It is further another object of the present invention to increase the frictional force of the elevating member against the water flow so as to facilitate up-and-down motion of the elevating member.
According to the present invention, it is possible to prevent the washing articles from being damaged since the washing articles are being moved upwards and downwards by the pulsator having elevating member. Also, in the washing machine provided with the pulsator according to the present invention, since the washing operation is carried it can be achieved drastically improved effect. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a cross sectional view showing a conventional pulsator;
FIG. 2 is a partially cutaway view showing flow line of the washing water in a washing machine having a conventional pulsator;
FIG. 3 is a cross sectional view showing operating state in a washing machine of the first embodiment according to the present invention,
FIG. 4 is a enlarged sectional view showing the engagement of an elevating member and a rotating member in FIG. 3;
FIG. 5 is a section view of the pulsator of the second embodiment;
FIG. 6 is a partial perspective view illustrating the operating relation between the elevating member and the rotating member in the second embodiment;
FIG. 7 is a partially cutaway view showing flow line of the washing water in a washer having the pulsator of the second embodiment;
FIG. 8 is a sectional view showing a assembling state of the rotating member and the elevating member of the third embodiment;
FIG. 9 is a cross sectional view illustrating flow line of the washing water due to the rotating of the pulsator of the third embodiment;
FIG. 10 is a cross sectional view illustrating flow line of the washing water due to the rotating of the pulsator of the fourth embodiment;
FIG. 11 is an exploded perspective view showing the principal parts of the fourth embodiment;
FIG. 12 is a sectional view showing assembled state of the principal parts in FIG. 11;
FIG. 13 is a sectional view illustrating flow line of the washing water due to the rotating of the pulsator of the fifth embodiment;
FIG. 14 is a enlarged sectional view showing the engagement of the elevating member and the rotating member is FIG. 13;
FIG. 15 is a sectional view illustrating flow line of the washing water due to the rotating of the pulsator of the sixth embodiment;
FIG. 16 is a perspective view showing assembled state of the elevating member and the rotating member of the sixth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4. Referring to FIG. 3, in a wash tub 101 there is mounted vertically a rotating shaft 102 driven by the driving force of a driving motor 114 which is transmitted through a pulley 116, a belt 118 and a pulley 117, and to the rotating shaft 102 is mounted a pulsator 103 as to be rotated to generate water flow in the wash tub 101. To the central portion of the pulsator 103 is inserted a rotating member 105 by using a fixing part 104 formed at the lower portion thereof, and a dimple 120 is formed on the upper end of the rotating member 105. In addition, the rotating member 105 is coupled with an elevating member 122 to generate heart-shaped water flow in the wash tub 101, wherein the elevating member 122 is provided with a guiding protrusion 121 being contacted with said dimple 120 so as to move along the surface of said dimple 120.
Therefore, when the driving motor 114 starts to rotate, the driving force of the driving motor 114 is transmitted to the rotating shaft 102 through the pulley 116 mounted on the upper end of the motor shaft 115, the belt 118 and the pulley 117 mounted on the lower end of the rotating shaft 102, and the pulsator 103 which is coupled with the rotating member 105 mounted on the upper end of the shaft 102 begins to rotate. At the same time, the guiding protrusion 121 projected from the inside of the elevating member 122 moves along the surface of the dimple 120, so that the elevating member begins to move upwards and downwards so as to push up the washing articles. Thus, the washing operation is to be completed without entanglement of the washing articles.
Next, the second embodiment of the present invention will be described in detail with reference to FIG. 5 through FIG. 7. FIG. 5 is a sectional view showing a pulsator according to the present embodiment, and FIG. 6 is a partial perspective view illustrating the operating relation between the elevating member and the rotating member.
Referring to FIG. 5 and FIG. 6, the rotating member 211 having a scroll groove 211a engraved on the surface is projected upwardly from the central portion of the pulsator, and the elevating member 212 is disposed over the rotating member to move upwards and downwards along the scroll groove 211a.
In the present embodiment, as shown in FIG. 7, when the pulsator 210 starts to rotate, the washing water in the wash tub 220 flows along the flow line indicated by the arrow, and the elevating member 212 repeatedly moves upwards and downwards along the scroll groove 211a so as to push up the washing articles. Thus, gathering of the washing articles to the central portion of the pulsator can be prevented.
At the central portion of the pulsator, there are formed an operating space A between the insides of blades 213 and the outer surface of the rotating member 211, and an inward flange 213a extending from the inside of the blades 213 formed at the upper portion of the operating space A. And there are formed the scroll grooves 211a in a predetermined angle on the surface of the rotating member 211, and a returning groove 211b is formed between the upper scroll groove and the lower scroll groove.
On the other hand, the elevating member 212 disposed over the rotating member 211 has a hollow part in which the rotating member 211 is received, and at the inner peripheral surface of the elevating member 212 is formed a sliding protrusion 212a adapted to be inserted into the scroll groove 211a, and an outward flange is formed on the skirt of the elevating member so as to engage with the inward flange 213a.
In this pulsator 210 according to the second embodiment, the sliding protrusion 212a of the elevating member 212 is engaged with the scroll groove 211a and the lower end of the elevating member 212 is rotating into the operating space. As the rotating member 211 rotates, the sliding protrusion 212a moves upwards along the scroll groove 211a and moves downwards to the lower scroll groove through a returning groove 211b after reaching to the upper end of the scroll groove 211a, and repeats this operation as long as the pulsator rotates. And the elevating member 212 being moved along the scroll groove 211a is contacted with the inward flange 213a and restricted upward motion thereof by the flange 213a, so that separating of the member 212 from the operation space A can be prevented.
In this embodiment, it is possible to present the washing articles from being damaged since the washing articles being concentrated to the bottom of the wash tub 220 are pushed up by the elevating member.
Next, the third embodiment of the present invention will be explained with reference to FIG. 8 and 9. FIG. 8 is a sectional view illustrating the assembled state of the rotating member and the elevating member, and FIG. 9 is a schematic view showing flow line of the washing water due to the rotation of the pulsator.
Referring to FIGS. 8 and 9, the pulsator 320 includes the rotating member 321 which has a sliding portion 321a formed on its upper outer surface and a guiding dimple formed on its upper end surface, the elevating member 322 whose lower end portion is slidably contacted with the sliding portion 321a of the rotating member 321, and a coil spring 323 which is elastically supported between the upper end of the rotating member 321 and the inner bottom surface of the elevating member 322.
The upper end of the rotating member 321 is inserted into the hollow portion of the elevating member 322, and the skirt of the elevating member 322 extends to the hollow portion 322a so as to form an inward flange 322b. The upper portion of the rotating member 321 is inserted into the hollow portion 322a through the open end of the elevating member 322, and a sliding protrusion 322c projected downwardly from the inner surface of the member 322 is slidably contacted with the guiding dimple formed on the upper surface of the member 321 and slidably contacted with the sliding portion 321a.
In the above described embodiment, as shown in FIG. 9, when the pulsator 320 begins, to rotate back and forth, the heart-shaped water flow is generated in the water filled in the wash tub 301, and the elevating member 322 moves upwards and downwards along the guiding dimple formed on the upper surface of the rotating member 321 being rotated together with the pulsator 320. At this time, if the pressure of the washing articles and the washing water which flows along the flow line exceeds biasing force of the coil spring 323, the coil spring 323 is compressed and then the elevating member 322 moves downwards, if the biasing force of the coil spring is larger than said pressure, the coil spring is restored to the original state so that the elevating member 322 is moved upwards instantaneously.
In this type of pulsator, the elevating member 322 elastically supported by the coil spring 323 repeatedly moves upwards and downward according to variation of said pressure. Therefore, up-and-down water flow can be easily and smoothly generated through the motion of the elevating member 322 so that the entanglement of the washing articles is prevented.
In addition, the fourth embodiment of the present invention will be described in detail with reference to FIG. 10 through FIG. 12. FIG. 10 is a sectional view of the present embodiment, and FIG. 11 is an exploded perspective view showing the principal parts, and FIG. 12 illustrates the assembled state of the present embodiment. Referring to FIG. 10 through 12, the rotating member 405 in which the fixing part 404 is formed at the lower end thereof and its upper portion is formed to be broadened in its diament gradually toward the upper end is coupled with the pulsator 403 provided in the bottom of the wash tub 401 to generate the water flow, and a spiral groove 406 is engraved on the inner peripheral surface of the rotating member 405. Two guiding protrusions 408,408 formed at both sides of the lower outer surface of the elevating member 407 are inserted into the spiral groove 406 so as to the elevating member 407 moves upwards and downwards along the spiral groove 406. At the middle of the upper end of the elevating member 407 there is engraved an inserting groove 409 having guiding holes 410,410 formed at both sides thereof.
Further, a circular cone-shaped head 411 is disposed on the tapered open end of the rotating member 405, and as the elevating member 407 moves upwards and downwards, the head 411 pivots on shafts 412,412 projected from the both sides of the lower portion thereof. The lower portion of the head 411 is inserted into the inserting groove 409, and the shafts 412,412, then the shafts 412,412 of the head are inserted into the guiding holes 410,410. On the one end of the bottom surface there is formed a slant face S having a predetermined angle α, and a coil spring is provided between the inserting groove 409 and the slant face S for giving elastic force to the head 411.
In the present embodiment, as shown in FIG. 10 through FIG. 12, when the driving motor 414 disposed under the wash tub 401 starts to rotate, the driving force of the driving motor 414 is transmitted to the rotating shaft 402 through the pulley 416 mounted on the upper end of the motor shaft 415, the belt 418 and the pulley 417 mounted on the lower end of the rotating shaft 402, and then the pulsator 403 which is coupled with the rotating member 405 mounted on the upper end of the shaft 402 begins to rotate. At this time, the elevating member 407 whose guiding protrusions 408,408 are inserted into the spiral groove 406 engraved on the inner peripheral surface of the rotating member 405, moves upwards along the spiral groove 406 as indicated by the phantom line in FIG. 12, and also the circular cone-shaped head 411 connected with the upper end of the elevating member 407 moves upwards.
When the head 411 reaches the upper limit, the head 411 becomes to be inclined as indicated by the phantom line in FIG. 12 by the coil spring 413 disposed under the slant surface S having a predetermined angle e. Thus while the head becomes to be inclined to one side, the head beats the washing articles. When the guiding protrusions 408,408 of the elevating member 407 move downwards along the spiral groove 406, the head 411 being inclined restores to the original state and beats the washing articles again so that non-symmetrical water flow is generated by the beating of the head as shown in FIG. 10.
Accordingly, the entanglement of the washing articles can be minimized, and the washing is carried out effectively by the non-symmetrical water flow.
Next, the fifth embodiment of the present invention will be explained with reference to FIG. 13 and 14. Referring to FIG. 14, the upper surface 512 of the elevating member 502 is inclined in a predetermined angle β. The rotating member 513, the pulsator 503 and the elevating member 502 are operated in similar manner described in foregoing embodiments.
Therefore, the elevating member 502 is rotated by the driving force of the driving motor 508 which is transmitted through the rotating shaft 509 and the rotating member 513, and the elevating member 502 moves upwards and downwards by the contact between the guiding protrusion 510 and the dimple formed on the upper surface of the rotating member 513. When the elevating member 502 begins to rotate and oscillate vertically, the non-symmetrical water flow is generated in the wash tub 501 by the operating of the slanted upper surface 512. Accordingly, the entanglement of the washing articles can be minimized, and the washing is carried out effectively by the non-symmetrical water flow.
Next, the sixth embodiment of the present invention will be explained with reference to FIG. 15 and 16. Referring to FIG. 16, on the upper outer surface of the elevating member are disposed fins 623,623 maintaining an equal distance to each other. And the rotating member 605, the pulsator 603 and the elevating member 622 are operated in similar manner described in foregoing embodiments.
Therefore, the elevating member 622 is rotated by the driving force of the driving motor 614 which is transmitted through the rotating shaft 602 and the rotating member 605, and the elevating member 622 moves upwards and downwards by the contacting between the guiding protrusion 621 and the dimple formed on the upper surface of the rotating member 605. At this time, the fins 623,623 are struck against the water flow which flows around the elevating member 622 in opposite direction of the rotating, then resisting force acts to the fins 623,623 so as to facilitate the vertical oscillation of the elevating member. Accordingly, the elevating member 622 smoothly moves upwards and downwards, and the entanglement of the washing articles can be reduced.
In the present embodiment, although the elevating member is disclosed as having two fins 623,623, the elevating member may have plural fins or slanted fins.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.
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The invention relates to a pulsator with an improved structure and more particularly to a pulsator having punching function used in the washing machine. The pulsator of the present invention is composed of such improved structure that a rotating member has a guiding dimple formed on the its upper end surface, and an elevating member has a guiding protrusion projected from the inner surface. According to such pulsator, non-symmetrical water flow and up-and-down water flow can be generated easily so that the entanglement of the washing articles can be minimized, and the washing is carried out effectively.
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This application is a continuation of prior reissue application, filed Oct. 21, 1985, and having Ser. No. 789,790, now U.S. Pat. No. Re. 32,645.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to dynamic rock stabilizing fixtures for mine roof support applications.
2. Description of the Prior Art
The state of the prior art is well presented by James J. Scott in a paper A New Innovation In Rock Support-Friction Rock Stabilizers of Apr. 23, 1979 before the Canadian Institute of Mining and Metallury in Canada, and in the paper presented by James J. Scott in May, 1980 at the 21st U.S. Symposium on Rock Mechanics, the paper being entitled Interior Rock Reinforcement Fixtures. The prior art includes also the method of anchoring bolts in drill holes by Schuermann et al U.S. Pat. No. 3,108,443 of Oct. 29, 1963, the grouting of anchors in Simpson U.S. Pat. No. 4,096,944 of June 27, 1978 and the mine roof support of Rozanc U.S. Pat. No. 4,313,697 of Feb. 2, 1982. These examples are directed to the use of resins as anchoring means for rock reinforcement, and to means for mixing the resin anchoring means.
SUMMARY OF THE INVENTION
The present invention provides an improvement in dynamic rock stabilizing fixtures employed to effect support of the roof. The improvement may be embodied in placing in a bore hole in a roof rock structure a formable material of tubular or semi-tubular form having the characteristics of being both flowable and compressible under load, inserting the roof support anchor so it engages the formable material and initiates a cooperative reaction between the bore hole and the anchor, and generates tension in the anchor to react against the rock or geologic mass in the roof to the extent desired.
It is also a feature of the present invention to provide the anchor in the form of a rod or a threaded bolt or a rebar which reacts with the formable material to create a supporting thrust by the means of the formable material being wedged between the surface of the bore hole and the anchor, and in which the continuity of the friction in the system has the effect of developing thrust vectors radiating into the rock formation.
Still another feature of the present invention is to provide a roof support system in which the control over the anchorage capacity is by forming a rod with or without a thread or roughened surface on the anchor and adjusting the length of the anchor surface which is in working relation with the bore hole in cooperation through a formable material or equivalent force distribution mechanism which can be a body of material of flowable character, or a body in tubular, or split tubular or strip form, any of which is capable of establishing a large contact area between the surface of a bore hole and the surface of the anchor rod.
While the present embodiments may have several different forms, as will be discussed presently, an important improvement is in the attainment of shear strength in the anchor right from the start of the installation. That is, the anchor generates dynamic rock stabilizing results immediately which is quite advantageous over other means which employs resins or materials which must go through a setting or cure period. The improvement in performance is that rock stability and support can be quickly developed and radial loading forces can be generated in the rock or geologic mass beyond the near boundary of the bore hole.
A more complete understanding of the present invention will be found in the following description and illustrations pursuant thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
Presently preferred embodiments of the invention are shown in the following drawings, wherein:
FIG. 1 is a fragmentary sectional elevational view of an embodiment in which an anchor rod of threaded character is about to be threaded into a formable material of tubular characteristic inserted in a bore hole;
FIG. 2 is a similar fragmentary sectional elevational view of the embodiment of FIG. 1 after the anchor has been threaded home in the bore hole to illustrate the resulting conformation of the formable material with the anchor bolt threads;
FIG. 3 is a fragmentary sectional view showing a modification in which a formable material of tubular character is substantially equal to the bore hole depth to provide a protective sleeve for the unthreaded portion of the bolt;
FIG. 4 is a fragmentary elevational view of a modified formable material in the character of strips of a tube held at an end by an uncut collar;
FIG. 5 is a sectional view at line 5--5 in FIG. 4;
FIG. 6 is a further modification of a formable material in a clover-leaf type configuration;
FIG. 7 is a further modification of formable material which is rolled on itself and positioned in the bore hole so the free margins expand but remain in overlapped relation;
FIG. 8 is a fragmentary sectional view of a buttress thread profile having utility in this invention;
FIG. 9 is still another fragmentary sectional view of a modified buttress thread profile useful herein;
FIG. 10 is a fragmentary sectional view of a modified buttress thread having a sharp crest;
FIG. 11 is a fragmentary sectional view of an anchor rod having a rope thread profile;
FIG. 12 is a further fragmentary sectional view of a common screw thread which conforms generally to the American National Form;
FIG. 13 is a fragmentary elevational view of an anchor rod having a roughened surface treatment;
FIG. 14 is a fragmentary elevational view of an anchor rod having a smooth surface; and
FIG. 15 is a fragmentary elevational view, partly in section of a further modification of a bore hole filled with a formable anchor material for an anchor rod.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the view of FIG. 1 a bore hole 10 has been formed in a rock formation above the roof 11 of a mine passage. A roof support structure in the form of a dynamic rock stabilizing fixture is installed in the bore hole 10 in the following manner: First, means 12 or an equivalent a body of formable material is located in the bore hole 10 and may extend over a desirable portion of the bore hole length from the closed end 13 of the bore hole. The formable material may consist of a length of compressible and yieldable material. A tube or rolled sheet or crushed resin material selected from the group consisting of polyethylene, polyurethane or polyvinyl chloride (PVC) or similar material, can be semi-hard but sufficiently compressible to conform to the contour or surface 10a of the bore hole 10 as well as yield to the pressure of the threads 14 on the anchor rod 15. The formable material may be a foam material which is blown into the bore hole to fill a portion thereof prior to anchor rod insertion.
Following the placement of the first means 12 in the bore hole 10, an anchor rod 15 is installed by a combination of being vibrated, thrust or torqued into the material in the bore hole, or it may be installed by any of these efforts, to compress and force the material into acting or reacting with the rock formation to substantially immediately set up a dynamic stabilizing restraint therein. The term dynamic is an adjective to characterize motion or change in relation to force or variation in intensity of an applied force. In relation to the subject matter herein, the term describes the ability of the present fixture to apply force on the geologic structure to replace the forces which have been disturbed by removal of some geologic mass. The elongated spiral wedge (FIG. 2) which corresponds to the threads is forced to exert an outward (see the arrows) thrust against the bore hole wall 10a. The tension in the bolt creates forces in the roof from a support plate 16 or geologic support (see arrows) which generates a dynamic support pattern which surrounds the bore hole open end. The threads 14 on the anchor bolt 15 may be cast, forged, machined or roll-formed so as to have a profile seen in any one of the views of FIGS. 8, 9, 10, 11 or 12, as will be explained presently.
The anchor bolt 15 carries with it the thrust plate 16 which is captured by the rod head 17 which is shaped to accept the drive end of an installation machine. the installation machine may be any of the commonly used types which exert a straight thrust or a combined thrust and torque, or any of the foregoing with a vibratory action, or just a vibratory action. The anchor rod 15 is driven into the bore hole 10 until the plate 16 contacts the roof 11. Typical vector diagrams in the Scott paper (supra) of 1980 show the direction of thrust of the anchorage and the reaction of the support plate 16. Such vector diagram has been illustrated in FIG. 2.
The fixture which is employed in the foregoing system comprises a tubular component selected from materials which may be a normal tube but which may be fractured or split when subjected to severe compression loading. The material of the tube must be capable of flowing when compressed so as to lock the rod in place in the bore hole, or to conform to the surface of a bore hole in the rock formation, as well as conform to the anchor rod when treated with threads or roughness. The anchor which may be normally formed of a low carbon steel having a 40 to 80 thousand psi yield and capable of responding to the formation of threads by roll forming methods, has threads formed as buttress type (FIG. 7) having a buttress angle A which may vary from 30° to as much as 80° perpendicular to the anchor rod axis. The thread pitch is such that the rate of advance of the anchor rod into the bore hole is compatible with the feed rate of the installing apparatus so the rod does not advance so fast the apparatus cannot maintain engagement. A buttress thread having about 4 threads per inch and a single start has been found to be satisfactory. Multiple start threads may also be employed.
Considering, for example, the rock stabilizer fixture seen in FIG. 1, and for a bore hole of substantially one-inch in diameter, the anchor rod thread length may be as short as four to six diameters of the bore hole, and it may be threaded through its entire length to provide a full contact anchor when the conditions warrant that treatment. The thread crest can be as much as fifteen-sixteenth inch thus providing an average dimension for the annular space of about one-thirty second of an inch. The thread root or minor thread diameter may be about three-fourths inch. The formable means cooperating with the foregoing anchor rod of threaded character, when in the form of a tube, may have a wall thickness of from about one-sixteenth inch to as much as one-hundred percent greater than the radial dimension of the annular space. When the formable means is in the form shown in FIG. 4, its thickness is in the range of two-hundred percent of the radial dimension of the annular space.
The fixture of FIGS. 1 and 2 illustrates the immediate dynamic restraint which takes place as the anchor 15 is installed into the formable means 12 in the bore hole 10. The compression of the means 12 exerts radially directed loads in the rock formation as depicted by the arrows. As the anchor attains its fully inserted position with the plate 16 abutted on the roof 11, the axially directed loading in the anchor develops multiple resultant force vectors 30 acting in many directions in the rock formation. The threads 14 on the anchor rod 15 compress the formable means 12 into a substantially continuous spiral wedge W (See FIG. 3) which distributes the loading in the rock formation along the length of the bore hole surface 10a. If the bore hole develops some recesses or enlargements during its drilling, the formable material will be forced by the anchor rod to expand at such zones so the spiral character of the wedge may be reduced or interrupted. The length of the anchor rod which acts on the rock formation allows for control over the stabilizing effect deeming necessary and the capacity of the anchorage.
The embodiment of the fixture, as depicted in FIGS. 1 and 2, comprises a separate body of formable material 12 which is inserted, independently, into the bore hole 10 for penetration, thereafter, by the anchor rod 15. The body of material 12, as shown, has a length which is substantially less than the length of the bore hole 10. Consequently, the body of material 12 is clear of, and remote from, the open end of the bore hole 10; it is installed only in close or proximate adjacency to the closed end of the bore hole 10 and, therefore, it is penetrated only by the leading, end portion of the rod 15. Resultantly, the body of material 12 becomes interpositioned between the wall of the bore hole 10 and only the aforesaid end portion of the rod 15. It is only such end portion of the rod 15, then, which becomes locked in the bore hole 10.
As seen in FIG. 3, the formable means 12 is extended for the entire length of the bore hole 10 while the anchor rod 15 has been formed with threads 14 for less than the full length thereof. The means 12, in this instance, is performing a function of protectively encasing the rod 15 against deterioration from effects that may arise from the surrounding rock formation.
A modified treatment of formable material is seen in, FIGS. 4 and 5 where the means 18 may comprise strips 19 of the foregoing compressible material held together by an end collar or ring 20. Each strip will, of course, be substantially equal in length, but the circumferential extent of the strip 19 can be varied.
Still another treatment of the formable material 21 is seen in FIG. 6 where the circumferential extent of the material is greater than the circumference of the bore hole 10. In that event, the material will buckle or it may be initially formed into a quasi-clover leaf in cross-section so that certain lobes 21a extend radially into the central area and intervening lobes 21b are in contact with the bore hole 10. When the threaded anchor bolt is inserted it will force the material of lobes 21a into conformation to create spiral wedges, much like the character of spiral wedges to be formed in the case of the means 12 of FIG. 2.
Still another treatment of the formable material is seen in FIG. 7 where, with sheet material 22, the circumferential extent of the material is greater than the circumference of the bore hole 10. In that event, the material will overlap at 22a into the central area while still in contact with the bore hole. When the threaded anchor rod is inserted it will force the material 22 into conformation of interrupted spiral wedges, much like the character of spiral wedges to be formed in the case of the means 18 of FIG. 4.
Turning now to FIG. 8, the anchor 15 is seen in section to have a buttress thread 14 in which the buttress surface 14a may have an angular relation A to the perpendicular to the axis of elongation of the anchor which may vary from about 30° to about 80°. This form of buttress thread has generously rounded thread crests 14b.
A modified buttress thread 23a is seen in FIG. 9 where the anchor 15a has the thread crest formed with a slight flat surface 23a.
The anchor 15b is seen in section in FIG. 10 to have a still further modified buttress thread 24 in which the buttress surface 24a may have an angular relation A to the perpendicular to the axis of elongation which may vary from about 30° to about 80°. This form of buttress thread has normal sharp thread crests 24b.
An alternate to the buttress type thread is the anchor 15c with rope thread 25 seen in FIG. 10. This thread is more open and is generously rounded.
A further modification of a useful thread is seen in FIG. 12 which is an American National Form of thread 25a on a rod 15d.
As before mentioned, the anchor may vary in surface treatment from any of the threaded forms to a rough surface 26 as in FIG. 13 where one form of surface threatment may be such as is found in reinforcing bars and rods. In FIG. 13, the surface is press-formed with one or more longitudinal ribs 26a and lateral ribs 26b.
The simplest form of anchor is a plain, smooth surface rod 27 as seen in FIG. 14. The rod 27 is formed with a lead-in end 28 for ease of entry, and the previously described rods may be similarly formed.
Returning to FIGS. 1 and 2, it can be observed that the annular space 29 between the anchor rod 15 and the surface 10a of the bore hole 10 is substantially less than the wall thickness of the formable means 12. As the anchor 15 is installed into the tube 12 the tube wall is compressed so it conforms with the bore hole surface 10a and fills the threads 14, with the result that the rock or geologic mass is loaded, as depicted in FIG. 2. There is also a circumferential loading of the formable material surrounding the rod 15. The tension in the rod produces angularly downwardly resultant pressure vectors 30. All of these forces are dynamic as they become immediately active as the rod 15 is moved into final position and provides an immediate restraint to rock formation near the bore hole. The vector forces near the crest of the thread are larger than the force vector near the root of the thread, and this results in a variable spiral loading through the formable material on the rock.
In the use of the threaded anchor 15, there is a definite spiral wedge W formed (See FIG. 3) in the annular space 29. Tests have confirmed the presence of the spiral shaping in the outer surface of the tubular means 12 and also the spiral shaping in the inner surface. The same impressions are formed in the formable material when it takes the modified forms seen in FIGS. 4, 5, 6 or 7 as well as when the anchor of FIG. 13 is employed.
When a smooth anchor rod 27 of FIG. 14 is employed, it is installed with the annular space between it and the bore hole overfilled with formable material so that a high friction loading is developed between the smooth surface and the formable material due to the radial and circumferential forces acting thereon as depicted according to FIG. 2.
The foregoing specification has set forth characteristics of the present improvement which call for providing formable material in such volume greater than the volume of the annular space around the anchor rod so that active anchorage is obtained and the rod is locked up in its position. The friction grip between the rod and the bore hole is improved whether the rod is threaded or roughened or smooth. It has been determined that a tubular formable material will substantially stay in its initial position during insertion of the anchor bolt. The performance of the present fixture is found to provide superior rock stabilization and has economic advantages not realized by older fixtures.
Referring to FIG. 15, the bore hole 10 in the rock formation is filled up to a desired volume with a flowable material by suitable means initially in a cartridge. The Material may be selected from some cellular composition which will act very much like tubular means in that it will be compressed by the rod as it is inserted and generate the immediate rock restraint that has been discussed previously. In FIG. 15 the bore hole 10 received the flowable material 31 which is forced by the insertion of the rod 15 to propogate along the rod in the annular space 29 and substantially immediately establish rock stabilization. The material 31 may be any of the before mentioned resins, with a retardent agent, which is placed in the bore hole 10 by a blowing agent such as freon or similar agent, or air. The resin reacts in the air to expand and form a body which frictionally supports itself in the bore hole. The anchor rod 15, in any of its thread forms is inserted and causes the body of material to propogate along the annular space 29 and form the wedge locking the anchor in the bore hole. In addition, the material may be a shredded and deformable material with a binder which is used merely to hold the material in place until a threaded type rod is installed, primarily by application of torque. The friction generated between the rod and the body of material 31 is sufficient to arrest tendency of the material to want to cause the rod to rebound and back out of the bore hole.
It can now be appreciated from the foregoing details of the preferred embodiments that the friction anchor may be in the form of either a threaded bolt, a rough surface rebar or a smooth rod. In assembling the fixture it can be appreciated that whichever form the anchor element of a fixture assumes, the formable material arranges itself or is forced to become wedged between the surface of the anchor and the surface of the surrounding bore hole. In order to obtain the wedging action the annular space surrounding the anchor itself must have a radial dimension which is smaller than the thickness of the formable material which is provided to lock the anchor in the bore hole. In certain cases as shown in FIG. 1, the formable material has a greater volume than the volume of the annular space between the anchor and the bore hole. When the formable material assumes the configuration as shown in FIG. 4, the volume thereof is not as important as is the thickness of the strips. In the form of the formable material of FIG. 6 the substantial increase in the circumferential surface of the formable material relative to the circumferential dimension of the bore hole may develop a volumetric differential between the annular space surrounding the anchor and the body of the formable material.
In its broadest aspect, the rock support fixture comprises a formable body of compressible material (FIGS. 1, 4, 6, 10 and 15) which is located in the bore hole and has a shape, or is capable of being arranged, to enable it to engage the surface of the bore hole and to receive the anchor rod and lock it in position, and an anchor rod having a diameter less than the bore hole diameter such that an annular space is formed therebetween to receive the formable body. The placement of the rod within the formable body develops substantially immediately shear strength under compression of the material, and a dynamic radial loading on the rock or geologic mass, and the coming together of the formable body and the anchor rod establishes an active rock or geologic mass reinforcement without any delay or waiting time. The fixture is completed with a support plate retained by the rod in supporting engagement with the geologic mass at the bore hole entrance.
It can be appreciated that the formable body can assume several different configurations as above specified or equivalents thereof, and the anchor may also assume several different configurations with respect to presenting a plain surface to the formable material or having surface treatment which may vary in respect of thread formations or rebar surface treatment. The present fixture is intended to and does develop immediate restraint of the rock at the time of insertion of the anchor. The anchor rods, in whatever form, are moved into position in a dynamic manner by being subject to a combination of thrust and torque or are inserted with a combination of thrust and repetitive impact such as is generated by an air hammer. In the placement of a threaded rod, torque is primary and thrust is secondary, but when placing a rebar thrust or impact is primary and some torque is helpful or may be required. In a rock stabilizer of the present invention the formable body develops friction contact with the surface of the bore hole, whether smooth or irregular, and the rod maintains the formable body in a state of dynamic support of the geologic mass so that any shift of the rock relative to the anchor rod does not result in loss of contact or anchorage along the length of the formable body.
It should now be understood that the preferred embodiments of the present invention may have variations or modifications without departing from the scope of the invention herein disclosed.
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Dynamic rock stabilization apparatus in the form of an anchor fixture for use with a roof plate in which the fixture has an anchor rod formed with a surface configuration extending from a lead-in end to the opposite headed end for at least a part of the length of the rod, and a hollow body providing a wall of formable and compressible material having a length less than the depth of a bore hole in the rock structure into which it is to be placed between the rod and the surface of the bore hole, the body engaging the surface configuration of the rod to effect a locking engagement with the rod such that when assembled in a bore hole the body wall has a thickness sufficient to be compressed between the rod surface configuration which has a diameter less than the bore hole and the bore hole surface, and to apply dynamic forces through the rock as a result of the compressibility of the body. The invention includes a method of effecting dynamic rock stabilization by placing a body of formable material in a bore hole and inserting an anchor rod into the body so it engages the body and initiates a cooperative reaction between the bore hole and the rod to stabilize the rock structure.
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BACKGROUND OF THE INVENTION
The present invention relates to an aircraft including an apparatus for measuring the load sustained by an aircraft component and to a method of measuring such a load. In particular, the present invention relates to an apparatus for determining the load sustained by an aircraft when braking and/or maneuvering the aircraft on the ground.
When an aircraft maneuvers on the ground (including, for example, immediately after touch down), the aircraft is subjected to various loads including vertical wheel to ground loads and horizontal drag loads including, for example, loads caused by friction between the tires of the wheels of the aircraft and the ground. The landing gear is subjected to significant horizontal loads on braking. The landing gear and other components of the aircraft have to be carefully designed in order for the aircraft to be able to withstand such loads, and other operational loads, but without unduly increasing the mass of the aircraft.
By using a load measuring device as part of a feedback braking system it is possible to limit, at least in part, the maximum load sustained by the airframe, landing gear, or a part thereof and/or to facilitate efficient braking of the wheels. It may also be advantageous to use load measuring devices during the testing and development of new aircraft.
It is known to use strain gauges as part of such load measuring devices. These, however, have disadvantages associated with them. For example, strain gauges may have to be bonded to the structure being monitored, may require specialist maintenance, may only be able to provide a local load measurement, may be easily damaged, may be susceptible to noise and/or may require temperature compensation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a load measuring apparatus for use on an aircraft which mitigates one or more of the disadvantages outlined above. Alternatively, or additionally, it is an object of the present invention to provide an improved apparatus capable of providing information from which an indication of the load sustained by an aircraft component can be ascertained.
The present invention provides an aircraft including an apparatus for measuring a load on an aircraft component, the apparatus including a processing unit, a controllable source of light, and a detector able to detect light emitted from said source, wherein
the source and the detector are situated in a region that is protected from the environment to the exterior of the aircraft,
the apparatus is arranged so that, when the aircraft component is subjected to a load of the type to be measured, relative movement of the detector and the position of the light from the source in the region of the detector is caused,
the detector in use generates in response to light received from the source a signal that is received by the processing unit, the signal being dependent on the relative positions of the detector and the light from the source in the region of the detector, and
the processing unit is arranged to provide an output signal dependent on the load sustained by the aircraft component.
Protecting the source and the detector from the environment to the exterior of the aircraft enables the detector and source to function without being significantly affected by environmental conditions such as for example water in the atmosphere.
The loads sustained by the aircraft component can cause a part of the component to elastically deform (for example by bending, twisting and otherwise moving and/or deforming) in relation to the rest of the aircraft. Thus, by measuring such movements it is possible to ascertain an indication of the load sustained by the aircraft component.
One advantageous and preferable feature of the apparatus of an embodiment of the present invention is that there need be no electrical contact between the source and detector. Preferably, the apparatus is so arranged that, in use, the light from the source detected by the detector travels through a gaseous medium, at least for the majority of the distance between the source and the detector, and preferably for the entire distance.
It will be understood that it is within the scope of the present invention for the detected light received from the source to have traveled on a path that diverges from the notional straight line on which the detector and the source lie. For example, the detector of the apparatus of the invention may be arranged to receive reflected radiation from the source. In such a case, the detector and source could be placed adjacent to each other, for example. In such a case it will be understood that when the aircraft component is subjected to a load of the type to be measured, relative movement will occur between the detector and the position of the light from the source in the region of the detector, but that there may be no relative movement between the detector and the source.
Preferably the signal that is generated by the detector in response to light received from the source is dependent on the relative positions of the source and detector. Thus, in accordance with this preferred feature, the present invention provides an apparatus, for example of an aircraft, for measuring a load on an aircraft component, the apparatus including a processing unit, a controllable source of light, and a detector able to detect light emitted from said source, wherein
the source and the detector are situated in a region that is protected from the environment to the exterior of the aircraft,
the apparatus is arranged so that, when the aircraft component is subjected to a load of the type to be measured, relative movement of the source and detector is caused,
the detector in use generates in response to light received from the source a signal that is received by the processing unit, the signal being dependent on the relative positions of the source and detector, and
the processing unit is arranged to provide an output signal dependent on the load sustained by the aircraft component.
At least one of the source and detector may be fixed at a first position relative to a first part of the aircraft component. At least one of the source and detector may be fixed at a second position relative to a second part of the aircraft component, the first and second parts of the aircraft component being spaced apart. Preferably, one of the source and detector is fixed at the first position and the other of the source and detector is fixed at the second position.
The region in which the source and the detector are situated is preferably defined by a housing. The section of housing in which the source is situated may be freely moveable relative to the section of housing in which the detector is situated. There is preferably no significant resistance to relative movement, within preset limits, in at least one direction of the two sections of the housing. The two sections may be joined by a flexible joint. The flexible joint may for example comprise an annular bellows-shaped structure.
The housing is preferably in the form of a sealed container. The sealed container may for example provide the means for protecting the source and the detector from the environment to the exterior of the aircraft. Preferably, the sealed container is watertight.
The sealed container is preferably air tight. The sealed container preferably contains a protective atmosphere. The protective atmosphere may be in the form of a gas that has a relative humidity of less than 10% (“relative humidity” in this being the percentage of water by volume compared to the maximum amount of water the same volume of gas can hold at 1 atmosphere pressure and 25 degrees Centigrade). The protective atmosphere may be in the form of a gas that has a relative humidity of less than 5% and preferably less than 2%. The sealed container may contain a gas that has an oxygen content of less than 5% by volume, and preferably less than 1% by volume. The sealed container may contain a gas that has a nitrogen content of greater than 90% by volume, and more preferably greater than 95%.
The processor and/or any power sources that may be provided may be positioned outside of the housing.
The light source may comprise a solid-state source of light, for example an LED or a laser source. The detector may comprise a solid-state detector of light, for example a photodiode or a charge-coupled diode (CCD).
The detector preferably comprises a plurality of spaced apart sensors. The sensors in use preferably generate in response to light received from said source a signal or signals that in use are received by the processing unit, which signal or signals being dependent on the relative positions of the sensors and the light from the source in the region of the sensors. The sensors in use may generate in response to light received from said source a signal or signals that in use are received by the processing unit, which signal or signals being dependent on the relative positions of the source and the sensors.
The apparatus may be so arranged that the signal generated by the detector, whether in dependence on the relative positions of the sensors and the light from the source in the region of the sensors or on the relative positions of the source and detector, depends on the relative levels of intensity of light received by the sensors. The sensors may each be arranged to generate a current in dependence on the amount of light received by the sensor.
The signal generated by the detector may itself comprise a plurality of separate signals. The signal generated by the detector may, for example, comprise a plurality of separate components, each component relating to the signal generated by each sensor. The processing unit may for example perform a calculation involving values ascertained from the respective components. For example the processing unit may receive two signals, if necessary converting the two signals into digital signals, and then calculate the difference between the two respective digital signals. The difference so calculated may thus provide an indication of the amount of movement in a given direction of two of the sensors relative to the position of the light from the source in the region of the sensors. The difference so calculated may provide an indication of the amount of movement in a given direction of two of the sensors relative the source. The signal generated by the detector may alternatively, or additionally, comprise one or more components, wherein each component is representative of a combination of the signals from two or more sensors. The signals from the sensors may for example be combined before they are received by the processing unit. For example, the sensors may generate analogue signals and signals from two sensors may be combined in a comparator circuit, the output (a single signal) being sent to the processing unit.
A calculation may be performed by the processing unit in order to ascertain the movement of the detector relative to the source in a given direction, the calculation involving a comparison of the signal from one sensor with the signal from another sensor. The comparison may simply consist of ascertaining the arithmetic difference between the magnitudes of the signals.
The shape and intensity profile of the light emitted by the source and the shape and position of the sensors are preferably such that the intensity of light received by the sensor at a multiplicity of spaced apart positions along an axis perpendicular to the notional line linking the source and a sensor increases (in one direction) with each successive position along the axis. Preferably, the intensity of light received by the sensor at positions along a section of an axis perpendicular to the notional line linking the source and a sensor varies substantially monotonically.
The controllable source may emit a focused beam of light. In such a case, each sensor may produce a signal that is dependent on the area of each sensor within the beam of light. The beam of light is conveniently emitted substantially in one direction. It will be understood that the beam of light may change direction after being emitted from the source, for example by way of a reflection. The focused beam may be such that the intensity of light is substantially constant within a significant portion of the cross-section of the beam. Alternatively, or additionally, the intensity of light may vary depending on the position within the beam. The intensity of light may be at a peak in the middle of the beam and varies monotonically with distance from the middle. The beam may have an intensity profile that is symmetrical. The beam may have an intensity profile that in cross-section forms contours of equal intensity that are substantially circular in shape.
The apparatus may be so arranged that the signals from a pair of sensors are used to produce a signal representative of the position of the detector relative to the position of the light from the source in the region of the detector, in a single given direction. The apparatus may be so arranged that the signals from a pair of sensors are used to produce a signal representative of the position of the detector relative to the position of the source in a single given direction. The single given direction will generally be in a direction that is not perpendicular to the notional straight line connecting the two sensors, and is preferably parallel to the notional straight line.
Preferably the source is fixedly mounted in relation to a first location on the aircraft and each of the plurality of sensors is fixedly mounted in relation to a second location on the aircraft, wherein movement of the first and second locations relative to each other depends on the relative movement of the aircraft component. In such a case, the apparatus is preferably arranged so that movement of the plurality of sensors in a first direction relative to the source causes the intensity of light detected by one of two sensors to increase and causes the intensity of light detected by the other of the two sensors to decrease. Thus, the difference in the respective signals generated by the two sensors facilitates the provision of an indication of the amount of movement in the first direction of the two sensors relative to the source. In such a case, the processing unit preferably effectively calculates an output signal representative of the relative movement of the first and second locations.
The apparatus may conveniently be so arranged that the processing unit need never ascertain an absolute value of the relative movement of the detector, whether relative to the position of the radiation from the source in the region of the detector or relative to the source. The signal from the detector may for example be converted directly into a signal representative of a load without there being an intermediate step of converting the signal from the detector into a signal relating to the relative movement or separation in a given direction. The apparatus may be so arranged that only the change in relative positions of the detector and the light from the source in the region of the detector may be ascertained from the signal from the detector that depends on the relative positions of the detector and the light from the source in the region of the detector. Preferably the apparatus is so arranged that only the change in relative positions of the source and the detector may be ascertained from the signal from the detector that depends on the relative positions of the source and the detector.
The detector need only have one pair of sensors if the load to be measured is in one direction only. However, the detector may be able to measure loads in more than one direction. The detector may facilitate the measurement of relative movement along two substantially orthogonal axes. The detector may therefore include two or more pairs of sensors. For example, the plurality of sensors may comprise a first pair of sensors and a second pair of sensors, wherein, in use, the signals generated by the first pair are used to generate an output representative of the displacement of a part of the aircraft component in a first degree of freedom and the signals generated by the second pair are used to generate an output representative of the displacement of a part of the aircraft component in a second degree of freedom. The detector may comprise a quad-cell arrangement comprising four sensors arranged in close proximity to each other.
The notional line extending from the middle of one sensor of a pair to the other sensors of the pair may intersect the notional line extending from the middle of one sensors of another pair to the other sensors of that other pair. The notional lines may mutually bisect each other. The notional lines are preferably transverse to each other and may be perpendicular. The apparatus may for example comprise a detector having a pair of sensors in the form of a cross.
It will be appreciated that it would be possible for one sensor to form one half of each of two pairs of sensors, so that only three sensors need be supplied in order to provide the ability of the detector to measure loads in two dimensions.
The arrangement of the apparatus is preferably such that the notional straight line on which each pair of sensors lies is substantially transverse to the notional straight line on which the source and detector lie.
The sensors may be arranged such that each sensor is separated from each other sensor. The separation between a pair of sensors may be set in dependence on the wavelength of light emitted by the source and/or the resolution of measurement required. The sensors within a pair of sensors may be separated by only by a relatively small distance so that the sensors in each pair may be considered as being adjacent to each other.
The apparatus may be so arranged that in use the signal generated by the detector in response to light received from the source is representative of a relative position of the detector and the light from the source in the region of the detector, the position having at least two degrees of freedom. The apparatus may be so arranged that in use the signal generated by the detector in response to light received from the source is representative of a relative position of the source and detector, the position having at least two degrees of freedom.
The apparatus may include a pair of detectors. The pair of detectors may be positioned in a single housing.
The pair of detectors may be arranged to enable a torsional force sustained by the component to be measured. Alternatively, or additionally, the pair of detectors may be provided to enable the processor to compensate for such torsional loads on the housing in cases where the apparatus is used to measure a bending load or shear load. It might for example be desirable to compensate for torsional loads when measuring loads on a bent component.
Preferably, the pair of detectors facilitate the measurement of relative movement along two substantially parallel and spaced apart axes. Such a measurement provides information on relative translational movement in a direction parallel to the two axes and also on relative rotational movement about an axis perpendicular to the plane containing the two axes.
Each detector in the pair is preferably associated with a respective light source. Each of the pair of detectors may be able to measure the relative position of the or each source and the or each detector associated with the or each source, the position having two degrees of freedom.
The apparatus may be arranged to provide an output that is representative of the load sustained by the component. The output is preferably calculated by the processing unit. The processing unit may when calculating the output use data concerning the relationship between the relative movement of the component and the load sustained by the component. The data is preferably stored in electronic memory in or immediately accessible by the processing unit. The data may be calculated in advance by means of mathematically modeling the loading of the component, for example making use of finite element analysis techniques. The data may be ascertained in advance by making calibration measurements in relation to the aircraft component (or a component substantially identical thereto). Both such mathematical modeling techniques and calibration measurements may be used in combination. For example, a multiplicity of calibration measurements may be made of the relative movement of the aircraft component in response to successive different known loads. The processing unit may perform interpolation calculations when calculating the output with the use of the data.
The processing unit may form part of a control unit that is arranged to control the light emitted by the source. Alternatively, the processing unit need not perform any control function. The processing unit may include, or be in the form of, a signal processor and/or a micro-processor. The processing unit may comprise physically separate sub-units.
The source may be arranged to emit visible light. Such sources are readily available. The light emitted by the source may comprise invisible light. The source is preferably arranged to emit light having an intensity profile that peaks at a wavelength in the range of 300 nm to 1100 nm, and preferably within the range of 600 nm to 1000 nm. Other wavelengths of electromagnetic radiation may also be suitable of course.
The present invention may have application in relation to assessing the load on any aircraft component, where loading of the component causes movement of the component. The invention is of particular benefit in the case where the aircraft component is at least part of a landing gear of an aircraft.
As mentioned above, the aircraft component may be a part of a landing gear. The part of the landing gear may be a leg, or part thereof, of an aircraft landing gear. For example the part of the landing gear may be the outer cylinder of a shock absorbing part of the leg. The part of the landing gear may be a wheel axle. The part of the landing gear may be a brake pin. The part of the landing gear may be a bogey. It will be understood that the brake pin is the component that connects the brake rod and the brake piston housing of a landing gear.
The source and detector are preferably arranged to measure a substantially horizontal component of the movement made by the aircraft leg under loading.
The aircraft component could be at least a part of a wing of an aircraft. For example, the load sustained by a portion of a wing could be assessed by measuring the movement of one location on the wing relative to another.
The aircraft component could be in the form of a control surface, such as an aileron. The aircraft component could be in the form of a part of the fuselage. The aircraft component could be in the form of a horizontal and/or vertical lifting surface.
The aircraft may further include a load control system. The load control system may be arranged to monitor a measurement of the load sustained by the aircraft component, the measurement being ascertained from the output signal from the processing unit. The load control system is preferably arranged to control a part of the aircraft in dependence on the measurements so monitored. For example, the load control system may be arranged to control a part of the aircraft so as to reduce the loads sustained by the aircraft in the event that the load control system calculates that the load exceeds given criteria. The given criteria could simply be a preset threshold. The given criteria could alternatively or additionally be time dependent. The given criteria may be a threshold that varies in dependence on other parameters.
The load control system may be in the form of a braking control system. The aircraft component may in that case be a leg of an aircraft landing gear, a wheel axle or a brake pin for example. Preferably, the load control system monitors measurements from a plurality of detector-sensor pairs, which may be provided on different components. The braking control system may be arranged to control the braking in dependence on the loads monitored by the braking control system. The braking control system may for example be arranged to be able to control the braking force applied to the wheels of the landing gear. The braking control system may be arranged so that in the event that the braking control system detects that the load sustained by the leg exceeds a given threshold value, the level of braking is reduced. The braking control system may be arranged so that the output signal generated by the processing unit is received by the braking control system. The braking control system may be arranged to monitor the load sustained by the aircraft leg and to control the braking force applied in order that under normal operating conditions the load on the leg of the landing gear does not exceed a preset threshold. The preset threshold may for example correspond to the maximum load that the aircraft leg is designed to withstand during normal operation.
The load control system and the processing unit of the apparatus for measuring the load are preferably in the form of physically separate systems. However, it would be possible for the load control system and the processing unit to be part of a single control system. For example, a computer processor could perform the functions of both the load control system and the processing unit of the load measuring apparatus.
In accordance with the present invention there is also provided apparatus for measuring a load on an aircraft component, the apparatus including a controllable source of light, and a detector able to detect light emitted from said source, wherein
the source and the detector are situated in a housing that defines a protected region,
the apparatus is arranged so that, when the housing is subjected to a load of the type to be measured, relative movement of the detector and the position of the light from the source in the region of the detector is caused,
the detector in use generates in response to light received from the source a signal that depends on the relative positions of the detector and the light from the source in the region of the detector, the signal being suitable for conversion into an output signal that depends on the load sustained by the aircraft component.
In accordance with the present invention there is also further provided apparatus for measuring a load on an aircraft component, the apparatus including a controllable source of light, and a detector able to detect light emitted from said source, wherein
the source and the detector are situated in a housing that defines a protected region,
the apparatus is arranged so that, when the housing is subjected to a load of the type to be measured, relative movement of the source and the detector is caused,
the detector in use generates in response to light received from the source a signal that depends on the relative positions of the source and the detector, the signal being suitable for conversion into an output signal that depends on the load sustained by the aircraft component.
The source of light, the detector and the housing are preferably adapted to be suitable for use as the housing, source and detector of the apparatus of the aircraft according to any aspect of the present invention as described herein.
The present invention also provides an apparatus including a source, a detector and a processing unit all being adapted to be suitable for use as the source, the detector and the processing unit of the apparatus of the aircraft according to any aspect of the present invention as described herein.
According to another aspect of the invention there is provided an apparatus for measuring a load on an aircraft component, the apparatus including a processing unit, a controllable emitter of electromagnetic radiation, and a detector able to detect radiation from said emitter, wherein the apparatus is arranged so that, when the aircraft component is subjected to a load of the type to be measured, relative movement of the detector and the position of the light from the emitter in the region of the detector is caused, the detector in use generates in response to electromagnetic radiation received from the emitter a signal that is received by the processing unit, the signal being dependent on the relative positions of the detector and the light from the emitter in the region of the detector, and the processing unit is arranged to provide an output signal dependent on the load sustained by the aircraft component. The apparatus may be arranged such that when the aircraft component is subjected to a load of the type to be measured, relative movement of the detector and the emitter is caused, and the signal that is received by the processing unit is dependent on the relative positions of the detector and the emitter. In accordance with the present invention there is also provided a method of measuring a load on an aircraft component, the method including the following steps:
causing light to be emitted from a source,
measuring the light received by a detector from the source, the light measurement being dependent on the relative movement of the detector and the position of the light from the source in the region of the detector caused by a load on the aircraft component,
protecting the source and the detector from the environment to the exterior of the aircraft, and
calculating an indication of the load sustained by the aircraft component from the light measurement together with data concerning the relationship between the light measurement and the load sustained by the component.
Preferably the light measurement is dependent on the relative movement of the detector and the source caused by a load on the aircraft component.
The step of calculating an indication of the load may be performed as a single operation using the signals from the results of measuring the light by the detector. The method may include a separate step of calculating from the light measurement an indication of the relative movement of the source and detector. The method may include a separate step of calculating from the light measurement an indication of the relative movement of the detector and the position of the light from the emitter in the region of the detector. Such calculation may involve the use of data concerning the relationship between the light measurement and the relative movement of the source and detector, or more preferably the use of data concerning the relationship between the light measurement and the relative movement of the detector and the position of the light from the source in the region of the detector. The indication of the relative movement may relate directly to the relative movement and/or position of a part of the aircraft component. In such a case the step of calculating an indication of the load sustained by the aircraft component may be performed by calculating the load from the calculated indications of the relative movement together with data concerning the relationship between the relative movement of the component and the load sustained by the component. The indication of the relative movement of the detector and the position of the light from the source in the region of the detector, for example the indication of the relative movement of the source and detector, and the indication of the load may each be in the form of a numerical value. The numerical value(s) may be represented by digital or analogue electronic signals. The data used in the method may be calculated and/or determined by calibration measurements in advance and for example stored in a memory unit.
The apparatus of the invention may be used in the method of the invention. Thus, features described with reference to the apparatus of the invention may be incorporated into the method of the invention. Also, features described with reference to the method of the invention may be incorporated into the apparatus of the invention. For example, features already described with reference to the apparatus of the invention are described below with reference to their application in the method of the invention.
The detector used in the method preferably comprises a plurality of sensors. An indication of relative movement of the detector and the position of the light from the source in the region of the detector, for example an indication of the relative movement of the detector and the source, may thus be calculated from measurements of the relative amounts of light received by the sensors. The sensors may include a pair of sensors and the method preferably performs a calculation, for example to calculate an indication of the relative movement of the detector and the source, using the difference between the signals from the pair.
The indication of the relative movement of the detector and the position of the light from the source in the region of the detector may comprise an indication of movement in at least two dimensions or degrees of freedom. Preferably the indication of the relative movement of the source and detector comprises an indication of movement in at least two dimensions or degrees of freedom. The indication of the load sustained by the aircraft component may comprise an indication of the load in at least two dimensions or degrees of freedom.
The present invention also provides a method of controlling the loads sustained by an aircraft component. The method according to this aspect of the invention may include monitoring the loads sustained by the aircraft component by using the apparatus for measuring loads in accordance with any of the aspects of the present invention or by performing the method of measuring a load in accordance with any of the aspects of the present invention. The method according to this aspect of the invention may include a step of controlling a part of the aircraft in dependence on the results of the monitoring of the loads. The method according to this aspect of the invention may be performed when braking and/or maneuvering the aircraft on the ground. The method may for example be performed when maneuvering and braking the aircraft on the ground immediately after touch down when landing the aircraft. The aircraft may be braked by means of the application of one or more wheel brakes. Accordingly, the present invention also further provides a method of maneuvering an aircraft on the ground, the method including a step of controlling the aircraft according to the above-described method, wherein the loads on the leg of a landing gear of the aircraft are monitored and the steering and/or braking of the aircraft is controlled in dependence on the loads monitored.
The present invention may have application in relation to the measuring of loads on components, objects, or the like other than aircraft components. For example, loads on buildings or other structures such as bridges could be measured by means of the present invention. Thus the invention more generally provides an apparatus for measuring loads and a method of measuring loads as set out above except that the object of the measurements need not necessarily be in the form of an aircraft component. Also, the present invention may have a wider application in relation to the measuring of relative movement between two points (or two locations). The apparatus may but need not necessarily be arranged to measure the relative movement between two locations on an aircraft. The apparatus could for example be used to measure and/or monitor the change in shape of any object. Other features of the present invention as described herein may be incorporated, where appropriate, into this more general aspect of the invention.
DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way of example with reference to the accompanying schematic drawings of which:
FIGS. 1 a and 1 b show a wheel axle on which two load detectors of a load monitoring system are mounted in accordance with a first embodiment of the invention;
FIG. 1 c is a cross-sectional view of one of the load detectors shown in FIG. 1 a;
FIG. 1 d shows a landing gear leg on which a further load detector of the load monitoring system of the first embodiment of the invention is mounted;
FIG. 2 a is a cross-section of a landing gear showing a brake pin including a load detector of a load monitoring system according to a second embodiment of the invention;
FIG. 2 b shows two perspective views (one showing an enlarged portion of the other) of a landing gear bogey illustrating the position of the brake pin shown in FIG. 2 a , and
FIGS. 3 a and 3 b show a brake pin including a load detector of a load monitoring system according to a third embodiment of the invention.
DETAILED DESCRIPTION
FIGS. 1 a and 1 b show a wheel axle 2 (the wheel itself not being shown in those Figures) including two load detectors 4 that form part of a load measuring system according to a first embodiment of the invention. Each load detector 4 is in the form of a separate displacement measurement system 4 . The load detectors 4 are provided to monitor the part of the braking force directly reacted through the wheel axle 2 and also to monitor the vertical load.
The two displacement measurement systems 4 (one of which being shown highly schematically in FIG. 1 a ) are elongate in shape and extend a short distance in the direction of the axis of the axle 2 , their axes being spaced apart, and parallel to, and on opposite sides of, the central axis 6 of the wheel axle 2 . With reference to FIG. 1 c , each displacement measurement system 4 comprises a sealed cylindrical container 8 having one end 12 a within which there is mounted a quad-cell photodiode detector 10 (a detector comprising four photodiodes) and an opposite end 12 b within which there is mounted a laser source 14 , which in use directs a focused beam 16 of light towards the quad-cell detector 10 . Optical elements (not shown) are positioned in front of the laser 14 to focus the light beam 16 . Power to the laser 14 and signals from the detector 10 are provided by respective electric cables (not shown) that lead to an electrical connector 17 on the outside of one end 12 a of the container 8 .
The four photodiode sensors are fixed in position relative to each other, but as mentioned above are mounted such that there may be relative movement between the sensors and the light source. In use, light from the laser 14 is focused on to the detector 10 as a spot. The position of the centroid (the point at the centre) of this spot is calculated by comparison of the signals from the four quadrants (photodiode cells) of the quad-cell arrangement 10 . This calculation may be explained by considering the case where an equal intensity of light from the focused light beam 16 is received by each sensor. If the detector 10 or the laser light source 14 moves then the area of one sensor may become more exposed to the beam 16 than the opposing sensor in the detector 10 , thereby inducing a greater current in the sensor and a reduced current in the opposite sensor, respectively. The differential current thus indicates the relative position of the source 14 and the detector 10 .
For each pair of opposing sensors in the detector 10 , the currents from the pairs of opposite sensors in the detector 10 are combined in a difference circuit of a processor (not shown) that receives the signals from the respective displacement measurement systems 4 . The difference circuit effectively subtracts the current from one sensor of a pair from the current from the other sensor of the pair. When the sensor pair are in the “zero” position with respect to the beam 16 of light from the laser 14 , the current induced in each sensor is the same, thus the resultant output signal from the difference circuit is zero. Thus, the output from the difference circuit depends on the component of relative movement between the source and detector 10 along a single axis (in this case the x-axis). The output of the detector 10 can therefore be used to measure relative movement with two degrees of freedom.
The form of the relationship between the outputs from the difference circuits and the relative displacement is programmed into the processor during a calibration process. The signals from the difference circuits are then processed to calculate a load on the basis of a load model from the data relating to the relative displacement.
The solid-state laser and photodiodes used to monitor the loads acting on the landing gear of the aircraft all have a relatively high level of resolution and bandwidth. The detector 10 of FIGS. 1 a to 1 d is able to detect displacements of ±1,000 microns from the normal (central position) with a resolution of about 5 microns.
It will of course be appreciated that the rest position need not necessarily be one in which the beam 16 is centrally aligned with the sensors of the detector 10 or one where the currents generated by all of the sensors are equal. There may of course be advantages in having an off-centre rest (or unloaded) position if the loading on the component is likely to be in one direction more than another.
During the braking phase in particular the changes in the loads measured by the displacement measurement systems 4 are of a high frequency, fast transient mode. The solid-state devices used in this embodiment are able to detect such high frequency changes (unlike certain mechanical means such as strain gauges).
The respective ends 12 a , 12 b of the sealed container 8 are connected by means of a flexible bellows 18 arrangement which allows one end 12 of the container to move freely within certain limits relative to the other end 12 in the three orthogonal directions. The respective ends 12 of the container 8 are each fixedly mounted via expandable rings (not shown) in relation to spaced apart portions of the interior of the axle 2 . The container contains dry (less than 0.1% relative humidity) nitrogen gas 20 (at least 99% pure), which as a result of the container 8 being sealed protects the laser 14 and photodiodes of the detector 10 from the external atmosphere 22 .
Movement of the respective portions of the axle 2 caused by shear and bending loads on the axle 2 causes movement of one end 12 of each displacement measurement system 4 relative to the other end 12 . Differential measurements of displacement of the spot relative to the centre of the detector 10 are sent as electronic signals to the processor (not shown). By measuring the displacements by means of two displacement measurement systems 4 , the system compensates for errors generated by the torsion on the bent axle 2 . The displacement measurements are correlated with angular or lateral displacement of the incoming light (by means of the data in the pre-calibrated processor) and then converted into measurements of the shear load on the axle 2 . The shear load measurements calculated may then be converted into indications of the vertical load on each wheel. As will be explained in further detail below, the load measurements are monitored over time by the processor.
The load measuring system includes two further displacement measurement systems 4 provided on opposites sides on the exterior of the outer cylinder of the landing gear 24 as shown in FIG. 1 d . The arrangement and configuration of each displacement measurement system 4 is identical to that shown in FIG. 1 c . The signals from these displacement measurement systems 4 are sent to the processor. Thus the processor of the load measuring system additionally receives signals from these displacement measurement systems 4 which facilitate the calculating and monitoring of the global braking load, side loads and torsional loads around the landing gear leg 24 .
Each of the main landing gears on the aircraft and each of the wheels on each gear are provided with displacement measurement systems in the manner described above with reference to FIGS. 1 a to 1 d . Each displacement measurement system sends signals to the processor in response to the displacements measured. The processor of the load measuring system therefore receives signals from which it calculates in use various loads including the vertical load on each wheel, and the bending loads on each landing gear. Load information ascertained by the load measuring system is used to monitor the vertical loads on the aircraft during landing on a “per wheel” basis, and to ascertain the on-board weight and balance, and is also used by a braking control system, and a torque limiting system.
The operation of the load measuring system in use on an aircraft when landing will now be described with reference to the first embodiment. When the wheels of the landing gear are braked, after touchdown during landing for example, the resultant force on the landing gear tends to bend the landing gear leg about a horizontal axis that is perpendicular to the direction of movement of the aircraft. (In the description of the accompanying drawings the x-axis is taken to be the longitudinal axis of the aircraft, the y-axis is the other horizontal axis perpendicular to the x-axis and the z-axis is vertical.) Also, each wheel, associated axle and brake system are subjected to various loads, at least some of which are also monitored, such loads including torques and loads along the x-axis. The system is of course also able to monitor the torsional load around the landing gear leg and the side loads (along the y-axis) on a per landing gear basis.
After touchdown the brakes are applied and the loads on the landing gear and on the braking system become significant. The braking of the aircraft is controlled by a brake control system (not shown) that controls the braking in such a way as to reduce the likelihood of the loads on the landing gear that are monitored becoming greater than preset criteria/thresholds. The braking of the aircraft is also controlled by a torque limiting system (also not shown) that controls the braking in such a way as to reduce the likelihood of the torques induced by braking becoming greater than preset criteria/thresholds. The loads generated during ground maneuvering (mainly during the braking phase) are measured as they react through the landing gears of an aircraft. The processor monitors the loads as calculated, which in this embodiment include shear loads on the axle and vertical loads, horizontal loads and torsional loads on the landing gear leg. The loads are monitored continuously and if any of the signals (or the total of the signals) representative of the loads calculated by the processor exceed a threshold, the brake control system and/or the torque limiting system will sense the overloading by means of signal(s) supplied to the processor and the braking force will then be immediately reduced accordingly. This system of monitoring the loads and adjusting the braking accordingly is in the form of a feedback system.
By monitoring these loads, the aircraft can be controlled to reduce the maximum loads sustained by the aircraft and thus the weight of the landing gears and of the airframe may be reduced. The braking phase may also be controlled more effectively thereby enabling higher braking efficiency and less fatigue problems for the aircraft. The system also allows the implementation of the on board weight and balance measurements for the aircraft to be calculated with a per wheel resolution. The system enables the fatigue life of a landing gear to be monitored in more detailed manner than hitherto possible with mechanical strain gauges of the prior art. The load measuring apparatus is tolerant to different weather conditions, because the container is completely sealed.
The use of optical sources and sensors in a system for load measuring as described above in relation to the drawings has many potential advantages over the known use of strain gauges. The sensors not only provide good resolution and linearity, and measurements with two degrees of freedom (being easily scalable to provide more degrees of freedom), but are also suitable for measuring loads over a wide range of frequencies (including static loads and high frequency loads). Also the load measuring system of the above-described embodiment does not suffer from some of the problems associated with strain gauge based systems. The installation, use and maintenance of strain gauges require the skills of a specialist. Some strain gauges use very thin and delicate electrical wires to transmit information regarding the deformation being measured. Such thin wires can be easily damaged and generally operate at low electrical powers, and thus make the strain gauge susceptible to noise. The output of strain gauges is also often temperature sensitive and thus some strain gauges need temperature compensation. The gauges may require a settling down time after application, they are not easily maintainable, and a lengthy calibration process is often required. The solid-state devices as used in the manner described above in relation to the first embodiment mitigate at least some of the afore-mentioned disadvantages.
FIGS. 2 a and 2 b show a second embodiment of the invention. In this embodiment, the load measuring system receives load information concerning the loads on a brake pin 30 . These measurements can either supplement or replace the measurements made in respect of loads on the wheel axle 2 . As illustrated in FIG. 2 b , the bogey 32 of the landing gear accommodates six wheels (not shown in FIG. 2 b ), each of which being mounted for rotation about an axle 2 on which there is also mounted a set of brakes comprising brake disks 34 and a piston housing 36 . Torque during braking is reacted through a brake rod 38 that is attached to the brake piston housing 36 via a brake pin 30 (illustrated schematically in FIG. 2 b ). Thus, information concerning the braking torque and the vertical load reacted through the wheel may be measured by monitoring loads, and in particular shear loads, in the brake pin 30 . FIG. 2 a shows in cross-section the brake pin 30 and parts of the piston housing 36 and the brake rod 38 .
The effects of the loads applied during braking on the brake pin 30 tend to be in the form of shear and bending loads (represented by arrows 40 ) that modify the distance in the vertical direction (as shown in FIG. 2 a ), parallel to the shear plane 42 , between two points, one on each side of the shear plane 42 , separated by a distance (in the horizontal direction, as shown in FIG. 2 a ). This displacement is measured via a displacement measurement system 4 that is mounted within the hollow interior of the brake pin 30 . The displacement measurement system 4 comprises a solid-state laser 14 mounted on a first expandable ring 44 to one side of the shear plane 42 and a digital charge coupled device (CCD) array 50 mounted on a second expandable ring 46 to the opposite side of the shear plane 42 . Power to the laser 14 and signals from the CCD array 50 are provided by respective electric cables 48 that lead to an electrical connector 17 on the outside of one end 12 of the brake pin. The interior of the pin 30 is sealed, by means of sealing plugs 52 , and is filled with dry nitrogen 20 . The pin 30 has a flange 54 at one end 12 to engage with the brake rod 38 and has a screw thread at its opposite end onto which a nut 56 is screwed that engages with the brake piston housing 36 thereby providing a mechanical connection between the rod 38 and the piston housing 36 .
In the case where the first and second embodiments are combined, the processor of the load measuring system will have information concerning the loads on the brake pin, the wheel axle and the landing gear outer cylinder, thereby facilitating the in-service monitoring of the loads imposed on each wheel and each landing gear with more information, accuracy and reliability than hitherto feasible with the use of mechanical strain gauges. This in turn allows the performance of the brake control system and torque limiting system to be greatly improved, and allows the loads on the landing gear and wheels to be more effectively monitored and controlled (and kept within predetermined limits).
FIGS. 3 a and 3 b shows a brake pin 60 in accordance with a third embodiment. The brake pin 60 includes a displacement measurement system and is designed to be used in a load measuring system otherwise identical to the second embodiment. The main difference between the brake pin 60 of this third embodiment and that of the second embodiment is that the brake pin 60 in this case is made from a brake pin casing 62 and a separately manufactured displacement measurement system in the form of a cartridge 64 , the two separate parts being assembled to form the brake pin 60 . The displacement measurement system cartridge 64 comprises a low-stiffness cartridge inside which there are mounted a laser, and CCD. The separation of the laser and CCD is similar to that shown in FIG. 2 a and as such the laser and CCD are closer to the ends of the cartridge 64 than the laser and detector of FIG. 2 a are to the ends of the brake pin. The cartridge 64 is filled with nitrogen gas and sealed. Electrical connections to the laser and the CCD array are provided by a connector 66 on the outside of the cartridge 64 . During assembly of the brake pin, the cartridge 64 is inserted into and mounted within a standard brake pin casing 62 (either as an interference fit or by means of an adhesive or other bonding means). The function of the displacement measurement system is identical to that of the displacement measurement systems described above in relation to the first and second embodiments. As one end of the pin 60 moves relative to the other end, movement of the laser relative to CCD array is caused by means of the mechanical connection of the cartridge 64 to the brake pin casing 62 , the cartridge 64 being flexible enough both to allow such movement and to not modify significantly the mechanical properties of the brake pin 60 . The main advantage of this embodiment is that standard brake pin casings may be used.
It will be appreciated that various modifications may be made to the above-described embodiments of the invention without departing from the spirit of the invention.
The load measuring system could be used to monitor loads on other aircraft components. For example, trust loads, vertical tail-assembly loads, control surfaces loads, high lift devices loads, may each be monitored by means of a displacement measurement system 4 of the invention.
The apparatus could alternatively be used to monitor the loading and movement of other load bearing structures in other application relating to for example aerospace, civil engineering, automotive, or naval applications. The source and sensors would of course need to be modified to be suitable for such applications so that appropriate ranges of measurement at appropriate resolutions could be made. Such modifications would mainly consist simply of scaling the size of the components up or down as appropriate and would require only routine work to be conducted by the notional person skilled in the art.
The solid-state detectors mentioned above are stated to be able to detect displacements of ±1,000 microns from the normal (central position) with a resolution of about 5 microns. Of course, the range and resolution of the measurements able to be made by the measurement system will depend on the application and on the arrangement, location and separation of the light source and the detectors of the system. For example, when measuring loads on a landing gear leg the deflections are relative large and so a wide range of measurement is required. However, when monitoring the loads on a wheel axle in the region of constant shear, the absolute displacements to be measured are relatively small and a relatively higher resolution of measurement of change in position will be required.
Above reference is made to the control of the braking force applied by means of a feedback loop, wherein when the measured load exceeds a pre-set threshold, the braking force is reduced. The amount by which the braking force is reduced could be a pre-set amount, or could be related to the amount by which the measured load exceeds the threshold. Other criteria could be used to assess how and when to reduce the braking force. For example, the braking force could be reduced as quickly as possible (possibly to zero) for a pre-set time, after which the braking force is reapplied.
The incident light beam or spot image could be generated via light sources other than a laser. For example a one or more LEDs (light emitting diode) could be used. Similarly, the sensor arrangement of the detector may be in the form of any suitable arrangement including, for example, multi-element photodiodes other than quad-cell arrangements (for example having 2, 3, 5, or more diodes), position-sensing photodiodes, or other suitable solid-state detector devices.
Where, in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not delimit the scope of the independent claims.
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The load on an aircraft component, such as the load on a landing gear leg during braking, is measured with a contactless, all-weather displacement measuring system. The system includes a control unit a controllable microwave emitter of electromagnetic radiation and a microwave detector comprising a plurality of antennae. When the aircraft component is subjected to a load relative movement of the emitter and detector is caused. The detector generates in response to microwave radiation received from the focused beam of radiation emitted by the emitter a signal that is received by a signal processor of the control unit. The signal received by the control unit depends on the relative positions of the emitter and detector. The control unit is arranged to provide an output signal representative of the load sustained by the aircraft component. The system may be used to control braking in dependence on the output signal so as to maximize braking efficiency without overloading the landing gear leg.
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BACKGROUND OF THE INVENTION
Cleansing the skin is a desired result throughout the world. However the skin feel achieved during and after the process is subject to many different factors including cultural variations. In North America and Europe, it is generally desired to have a slippery feel. However many people in Asia prefer to have a feel which is less slippery and approaching or achieving a “squeaky clean” feeling. Another desired characteristic is a transparent composition, that is, one that a person can see images through. One of the factors important in achieving clarity is a low cloud point, the temperature at which a clear composition begins to become hazy. Having a low cloud point is of significance in countries where the climate is temperate and particularly where it is subtropical or tropical. Generally a cloud point of about 4-6° C. or even lower is desirable.
This is particularly significant where the aqueous composition undergoes hysteresis when it goes through its cloud point. Generally, when a composition descends through its cloud point it begins to become hazy. However, when the temperature is raised past its cloud point it becomes clear once again in a short period of time, for example usually no more than about 2 or 3 minutes at a temperature 1 or 2° C. about its cloud point. However certain compositions do not undergo this rapid change to clarity. Rather it takes a relatively lengthy period of time, even at a temperature significantly above its cloud point to achieve clarity once again. This physical phenomenon is oftentimes referred to as hysteresis.
This phenomenon has recently been encountered in a clear aqueous soap solution wherein the surfactants are primarily potassium salts of long chain carboxylic acids. After significant experimentation including a number of erroneous attempts to solve the problem, it has been discovered that the cloud point of such compositions can be significantly lowered as well as the removal of the significant issue of hysteresis through raising the pH of the composition. Surprisingly the high pH does not make the composition irritating as measured by clinical testing.
SUMMARY OF THE INVENTION
In accordance with the invention, there is an aqueous, clear cleansing composition comprising a cleansing effective amount of a potassium salt of a long chain alkyl carboxylic acid or mixtures thereof, the pH of said composition being from about 10.0 to about 11.0.
A further aspect of the invention is a method for lowering the cloud point of an aqueous clear cleansing composition having a cleansing amount of a potassium salt of a long chain alkyl carboxylic acid or a mixture thereof which comprises adjusting the pH of the composition to about 10.0 to about 11.0. A further benefit of the higher pH is that no hysteresis occurs even with the lower cloud point.
A pH of no more than about 10.8 can also be employed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The long chain alkyl carboxylate potassium salt or mixture thereof can have from about eight to about twenty carbon atoms, desirably about ten to about eighteen carbon atoms. Generally in order to cleanse the skin, there should be at least about 1 wt. % of the composition of the long chain alkyl carboxylate potassium salt or mixture thereof, desirably 2, 3, 4 or 5 wt. % of the composition. The maximum amount varies as the desired thickness of the composition or irritational aspects, but generally no more than about 30 wt. %, desirably 25 wt. % of the composition should be the potassium salt or mixture thereof.
Other anionic surfactants can be present in the composition such as amphoteric, nonionic, and cationic surfactants, although the composition can be without any of these surfactant families, particularly the cationic.
Examples of these surfactants include anionic nonsoap surfactants such as can be exemplified by the alkali metal salts of organic sulfate having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester radical (included in the term alkyl is the alkyl portion of higher acyl radicals). Preferred are the sodium, ammonium, potassium or triethanolamine alkyl sulfates, especially those obtained by sulfating the higher alcohols (C 8 -C 18 carbon atoms), sodium coconut oil fatty acid monoglyceride sulfates and sulfonates as well as alpha olefin sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of 1 mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and 1 to 12 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with 1 to 10 units of ethylene oxide per molecule and in which the alkyl radicals contain from 8 to 12 carbon atoms, sodium alkyl glyceryl ether sulfonates; the reaction product of fatty acids having from 10 to 22 carbon atoms esterified with isethionic acid and neutralized with sodium hydroxide; water soluble salts of condensation products of fatty acids with sarcosine; and others known in the art for example taurates, phosphate, and those listed in the McCutcheon's Encyclopedia of Surfactants.
Although not necessary other surfactants may be present in the composition. Examples of these surfactants include zwitterionic surfactants can be exemplified by those which can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is:
wherein R 2 contains an alkyl, alkenyl, or hydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 10 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorus, and sulfur atoms; R 3 is an alkyl or monohydroxyalkyl group containing 1 to about 3 carbon atoms; x is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus atom, R 4 is an alkylene or hydroxyalkylene of from 0 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.
Examples include:
4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-carboxylate;
5-[S-3-hydroxypropyl-S-hexadecylsulfonio]-3 hydroxypentane-1-sulfate
3-[P,P,P-diethyl-P 3,6,9 trioxatetradecyl-phosphonio]-2-hydroxypropane-1-phosphate
3-[N,N-dipropyl-N-3 dodecoxy-2-hydroxy-propylammonio]-propane-1-phosphonate
3-(N,N-di-methyl-N-hexadecyl-ammonio) propane-1-sulfonate; 3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate
4-(N,N-di(2-hydroxyethyl)-N-(2 hydroxydodecyl) ammonio]-butane-1-carboxylate
3-[S-ethyl-S-(3-dodecoxy-2-hydroxy-propyl)sulfonio]-propane-1-phosphate
3-(P,P-dimethyl-P-dodecylphosphonio)-propane-1-phosphonate; and
5-[N,N-di(3-hydroxypropyl)-N-hexadecyl-ammonio]-2-hydroxy-pentane-1-sulfate.
Examples of amphoteric surfactants which can be used in the compositions of the present invention are those which can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, sodium 3-dodecylaminopropane sulfonate, N-alkyltaurines, such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of U.S. Pat. No. 2,658,072, N-higher alkyl aspartic acids, such as those produced according to the teaching of U.S. Pat. No. 2,438,091, and the products sold under the trade name “Miranol” and described in U.S. Pat. No. 2,528,378. Other amphoterics such as betaines are also useful in the present composition.
Examples of betaines useful herein include the high alkyl betaines such as cocodimethyl carboxymethyl betaine, lauryl dimethyl carboxymethyl betaine, lauryl dimethyl alpha-carboxyethyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, stearyl bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl dimethyl gamma-carboxypropyl betaine, lauryl bis-(2-hydroxypropyl) alpha-carboxyethyl betaine, etc. The sulfobetaines may be represented by cocodimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, amido betaines, amidosulfobetaines, and the like.
Many cationic surfactants are known to the art. By way of example, the following may be mentioned:
stearyldimethylbenzyl ammonium chloride;
dodecyltrimethylammonium chloride;
nonylbenzylethyldimethyl ammonium nitrate;
tetradecylpyridinium bromide;
laurylpyridinium chloride;
cetylpyridinium chloride
laurylpyridinium chloride;
laurylisoquinolium bromide;
ditallow(hydrogenated)dimethyl ammonium chloride;
dilauryldimethyl ammonium chloride; and
stearalkonium chloride.
Additional cationic surfactants are disclosed in U.S. Pat. No. 4,303,543. See column 4, lines 58 and column 5, lines 1-42, incorporated herein by references. Also see CTFA Cosmetic Ingredient Dictionary , 4th Edition 1991, pages 509-514 for various long chain alkyl cationic surfactants; incorporated herein by references.
Nonionic surfactants can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. Examples of preferred classes of nonionic surfactants are:
1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 60 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.
2. Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine products which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.
3. The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration with ethylene oxide, e.g., a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms. Other ethylene oxide condensation products are ethoxylated fatty acid esters of polyhydric alcohols (e.g., Tween 20-polyoxyethylene (20) sorbitan monolaurate).
4. Long chain tertiary amine oxides corresponding to the following general formula:
R 1 R 2 R 3 N→O
wherein R 1 contains an alkyl, alkenyl or monohydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide moieties, and from 0 to 1 glyceryl moiety, and, R 2 and R 3 contain from 1 to about 3 carbon atoms and from 0 to about 1 hydroxy group, e.g., methyl, ethyl, propyl, hydroxy ethyl, or hydroxy propyl radicals. The arrow in the formula is a conventional representation of a semipolar bond. Examples of amine oxides suitable for use in this invention include dimethyldodecylamine oxide, oleyl-di(2-hydroxyethyl) amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, 3,6,9 trioxaheptadecyldiethylamine oxide, di(2-hydroxyethyl)-tetradecylamine oxide, 2-dodecoxyethyldimethylamine oxide, 3-dodecoxy-2-hydroxypropyldi(3-hydroxypropyl)amine oxide, dimethylhexadecylamine oxide.
5. Long chain tertiary phosphine oxides corresponding to the following general formula:
RR′R″P→O
wherein R contains an alkyl, alkenyl or monohydroxyalkyl radical ranging from 8 to 20 carbon atoms in chain length, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and R′ and R″ are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semipolar bond.
Examples of suitable phosphine oxides are:
dodecyldimethylphosphine oxide, tetradecylmethylethyl phosphine oxide,
3,6,9-trioxaoctadecyldimethyl-phosphine oxide, cetyldimethylphosphine oxide,
3-dodecoxy-2-hydroxypropyldi(2-hydroxyethyl) phosphine oxide stearyldimethyl-phosphine oxide,
cetylethyl propylphosphine oxide,
oleyldiethylphosphine oxide,
dodecyldiethylphosphine oxide,
tetradecyldiethylphosphine oxide,
dodecyldipropylphosphine oxide,
dodecyldi(hydroxymethyl)phosphine oxide,
dodecyldi(2-hydroxy-ethyl)phosphine oxide,
tetradecyl-methyl-2-droxypropylphosphine oxide,
oleyldimethylphosphine oxide, and
2-hydroxydodecyldimethylphosphine oxide.
6. Long chain dialkyl sulfoxides containing one short chain alkyl or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually methyl) and one long hydrophobic chain which contain alkyl, alkenyl, hydroxy alkyl, or keto alkyl radicals containing from about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety. Examples include: octadecyl methyl sulfoxide, 2-ketotridecyl methyl sulfoxide, 3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide, dodecyl methyl sulfoxide, oleyl 3-hydroxypropyl sulfoxide, tetradecyl methyl sulfoxide, 3 methoxytridecylmethyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl sulfoxide.
7. Alkylated polyglycosides include wherein the alkyl group is from about 8 to 20 carbon atoms, preferably about 10 to about 18 carbon atoms and the degree of polymerization of the glycoside is from about 1 to about 3, preferably about 1.3 to about 2.0.
The additional surfactants can be present in the compositions from about 0.5 to about 15 wt. % of the composition, desirably from about 0.75 to about 12 wt. % of the composition.
Water is present in the composition at quantities of at least about 50 wt. % of the composition, desirably at least about 60, 70 or 80 wt. % of the composition.
Additionally other components can be present in the composition including antimicrobial compositions such as Triclosan, perfumes, chelants such as EDTA, preservatives, vegetable extracts, colorants, thickeners, and the like.
The term “clarity” as used in the specification and claims means the product is visually clear. When the product is lowered below its cloud point temperature which can be 0° C. or even lower, such as −2, −3 or even −5° C., the composition becomes hazy. However, when the temperature is raised above its cloud point and held for a short period of time, nor more than about two (2) minutes, but can be one (1) minute or less, the composition once more becomes visually clear. PH is measured by an electronic Beckman pH meter at 25° C.
The hysteresis of the noncloud point stabilized system is visually noted at least by a minimum of haze in the composition. Below is a comparative example and an example of the invention showing the benefits and advantages of the inventive composition.
COMPARISON EXAMPLE 1
A clear aqueous composition has the following components
Component
Weight %
Potassium soap
18.0
Cocamide DEA
2.70
Lauryl polyglucose
2.50
Perfume
1.0
Sorbitol
0.64
Hydroxyethylcellulose
0.60
Potassium hydroxide
0.142
Sunflower/acacia extract
0.10
Preservative, UV protestant, colorant
0.43
Balance - water
QS
Total Materials
100.00
This composition has a pH of 9.6 and a cloud point of 4-6° C. The temperature of the composition is lowered to 3° C. Haze appears. The temperature of the composition is raised to 17° C. and held there for about 18 hours. The haze remains.
EXAMPLE 1
The same composition is prepared as in comparative Example 1 however its pH is adjusted to 10.5. Its cloud point is now about 0° C. The temperature is lowered to about −2° C. The composition develops a haze. The temperature is now raised to about 2° C. and held there for about 2 minutes. The composition is clear according to the aforestated visual clarity test. No hysteresis occurs. Additionally, the composition is non-irritating and passes the stability and preservative effectiveness test.
|
An aqueous, clear, cleansing composition comprising (a) a cleansing effective amount of a potassium salt of a long chain alkyl carboxylic acid or mixture thereof, the pH of said composition being from about 10.0 to about 11.0.
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FIELD OF THE INVENTION
[0001] The present invention relates to an enhanced oil recovery process for heavy oil in subterranean reservoirs and specifically processes for cyclic steam stimulation and/or steam flooding both improved by the additional step of injecting oxygen into the reservoir.
ACRONYM DICTIONARY OF TERMS
[0002] API American Petroleum Institute (density)
[0003] ASU Air Separation Unit (to produce oxygen gas)
[0004] CAGD Combustion Assisted Gravity Drainage
[0005] CIM Canadian Institute of Mining
[0006] COFCAW Combination of Forward Combustion and Waterflood
[0007] CSS Cyclic Steam Simulation
[0008] CSSOX CSS with Oxygen
[0009] DOE (US) Department of Energy
[0010] EOR Enhanced Oil Recovery
[0011] ETOR Energy to Oil Ratio (MMBTU/bbl)
[0012] HTO High Temperature Oxidation
[0013] ISC In Situ Combustion
[0014] JCPT Journal of Canadian Petroleum Technology
[0015] JPT Journal of Petroleum Technology
[0016] LTO Low Temperature Oxidation
[0017] OGJ Oil & Gas Journal
[0018] OOIP Original Oil in Place
[0019] SAGD Steam Assisted Gravity Drainage
[0020] SAGDOX SAGD+Oxygen
[0021] SF Steam Flood
[0022] SFOX Steam Flood with Oxygen
[0023] SOR Steam to Oil Ratio (bbls/bbl)
[0024] SPE Society of Petroleum Engineers
[0025] STARS Steam, Thermal and Advanced Process Reservoir Simulator
REFERENCES
[0000]
Anderson, R. E. et al—“Method of Direct Steam Generation Using an Oxyfuel Combustor”, Intl Pat. WO2010/101647 A2, 2010.
Arabian Oil & Gas Company, “Middle East Enhanced Oil Recovery”, May 5, 2011.
Balog, S. et al., “The Wet Air Oxidation Boiler for EOR”, JCP, September-October, 1982.
Bousard, “Recovery of Oil by a Combustion of LTO and Hot Water or Steam Injection”, U.S. Pat. No. 3,976,137, August, 1976.
Butler, R. M., “Thermal Recovery of Oil & Bitumen”, Prentice Hall, 1991.
Carcoana, A. N., “Enhanced Oil Recovery in Rumania”, SPE, April 1982.
Donaldson, E. C. et al, “Enhanced Oil Recovery II, Process and Operations Elsevier, 1989.
Escobar, E., et al, “Optimization Methodology for Cyclic Steam Injection with Horizontal Wells”, SPE/CIM, November, 2000.
Farouq Ali, S. M., et al, “The Promise and Problems of Enhanced Oil Recovery Method. JCPT, July 1996.
Frauenfeld, T. W. J. et al., “Effect of an Initial Gas Content on Thermal EOR as Applied to Oil Sands”, JPT, March, 1988.
Green Car Congress, “Chevron leveraging information technology to optimize thermal production of heavy oil with increased recovery and reduced costs”. Jun. 23, 2011.
Hanzlik, E. J., et al, “Forty Years of Steam Injection in California—The Evolution of Heat Management”, SPE, October, 2003.
Heavyoilinfo.com, “Wafra pilot delivers for Chevron”, Oct. 21, 2010.
Hong, K. C., et al, “Effects of Noncondensable Gas Injection on Oil Recovery by Steam Floods, JPT, December 1984.
L. Lake et al, “A Niche for Enhanced Oil Recovery in the 1990's, Oilfield Rev., January 1992.
Leung, L. C., “Numerical Evaluation of the Effect of Simultaneous Steam and Carbon Dioxide Injection of the Recovery of Heavy Oil”, JPT, September, 1983.
Luo, R. et al, “Feasibility Study of CO 2 Injection for Heavy Oil Reservoir After Cyclic Steam Simulation: Liaohe Oil Field Test”, SPE, November 2005.
Kumar, M., et al, “Cyclic steaming in Heavy Oil Diatomite”, SPE, March, 1995.
Moore, R. G., et al, “In Situ Performance in Steam Flooded Heavy Oil Cores”, JCP, September, 1999.
Moore, R. G., et al, “Parametric Study of Steam Assisted In Situ Combustion”, unpublished, February, 1994.
Nasr, T. N., et al, “Thermal Techniques for the Recovery of Heavy Oil and Bitumen”. SPE, December, 2005.
OGJ, “More US EOR Projects start but EOR production continues to decline”. Apr. 21, 2008.
Parrish, D. R. et al, “Laboratory Study of a Combination of Forward Combustion and Waterflooding—the COFCAW Process”, JPT, June, 1969.
Pfefferle, W. C., “Method for CAGD Recovery of Heavy Oil”, Intl Pat. WO2008/060311 A2, May, 2008.
Praxair, website, 2010.
Sarathi, P. “In Situ Combustion EOR Status”, DOE, 1999.
Sarkar et al, “Comparison of Thermal EOR Process Using Combinations of Vertical and Horizontal Wells”, SPE, February, 1993.
Stevens, S. H. et al, “A Versatile Model for Evaluation Thermal EOR Economics” SPE 1998.113, 1998.
The Jakarta Post, “12 Oil Companies to use EOR methods to boost production”, Jun. 27, 2011.
Thomas. S. “Enhanced Oil Recovery—An Overview”, Oil & Gas Sci& Tech, 63, 2008.
Wylie et al, “Hot Fluid Recovery of Heavy Oil with Steam and Carbon Dioxide”, U.S. Pat. 2010/0276148 A1, November, 2010.
Yang, X. et al, “Combustion Kinetics of Athabasca Bitumen from 1D Combustion Tube Experiments”, Nat. Res. Res., 18, No. 3, September 2009(2).
Yang, X. et al, “Design and Optimization of Hybrid Ex Situ/In Situ Steam Generation Recovery Process for Heavy Oil and Bitumen”, SPE, Calgary, October 2008.
Yang, X. et al, “Design of Hybrid Steam—ISC Bitumen Recovery Processes”. Nat. Res. Res., Sep. 3, 2009(1).
Zawierucua et al., “Material Compatibility and Systems Considerations in Thermal EOR Environments containing High-Pressure oxygen,” JPT, November, 1988.
BACKGROUND OF THE INVENTION
[0061] Steam Floods (SF) and Cyclic Steam Stimulation (CSS) are EOR processes that recover heavy oil and/or bitumen. These processes have been practiced for over 50 years. The processes use steam to deliver heat energy to the reservoir. An alternative to steam is to use mixtures of steam and oxygen. Oxygen delivers heat by combustion to supplement steam energy delivery.
[0062] The present invention supplements and improves steam floods (SF) by adding oxygen gas (SFOX) and supplements and improves cyclic steam stimulation (CSS) by adding oxygen gas (CSSOX).
Review of Prior Art
[0063] 2.1 Cyclic Steam Stimulation (CSS)
[0064] Perhaps the oldest process for thermal EOR is cyclic steam stimulation (also called the “huff” and “puff” process).
[0065] As seen in FIG. 3 , the process takes place using a vertical well, in three steps—first, steam is injected until injectivity/back-pressure limits injection rates or until a target slug size of steam is injected (the “huff” part of the cycle). For some reservoirs, fracture pressure may be exceeded during this phase to create fractures that aid in steam distribution and provide a conduit for oil flow. Second, the well is shut in and allowed to “soak” for a few weeks/months. This helps to spread heat by conduction and maximize the heated oil. Third, the well is put on production and oil flows to surface or is pumped to surface (the “puff” part of the cycle).
[0066] Although, a simple CSS process uses vertical wells. CSS can also be conducted using horizontal or deviated wells (Sarker (1993), Escobar (2000)). This can help distribute steam and shorten the flow path of heated heavy oil during the production phase.
[0067] CSS heats oil and reduces viscosity so the oil can more-easily flow to the production well. Steam also provides some gas drive during the production cycle. CSS also uses a form of gravity drainage, particularly if a partial steam chamber is retained around the vertical well during the soak phase ( FIG. 3 ). Oil can drain downward and replace steam as it condenses (Butler (1991)). The process has been labeled a “stimulation” process, because even if the native oil has some mobility but rates are low, by heating oil and the matrix rock, steam can reduce near-well-bore resistance to oil flow and increase recovery rates.
[0068] CSS started in the 1950's in field trials. The largest CSS project in the world is now the Imperial Oil (EXXON) project at Cold Lake, Alberta (Table 4, FIG. 5 , FIG. 8 ). For this project, steam injection pressures cause vertical fractures to help distribute steam and provide enhanced flow channels for heated heavy oil. SAGD has now overtaken CSS as Canada's leading steam EOR process (Table 4). Soon SAGD will be the largest single project for steam EOR in Canada. But, CSS will remain a large producer.
[0069] CSS has also been recently introduced to the mid east (Arabian Oil & Gas (2011)). Some of the issues with CSS include the following:
(1) For heavy oils, recovery is limited to about 20% OOIP (Butler, (1992). Another process may be necessary, post CSS, to exploit the reservoir (2) SOR deteriorates (increases) as the project matures. (3) Production is not continuous, for isolated wells (4) Inter well communication may develop and necessitate cycle coordination of several wells and/or a change in recovery process. (5) For bitumen, steam injectivity is too poor to run CSS (6) High pressure CSS requires monitoring to prevent well bore damage (7) Steam override
[0077] 2.2 Steam Floods (SF)
[0078] If injectivity is good or if CSS wells start communicating, the process can be changed to a steam flood, where steam is injected continuously into one (or more) well and “pushes” heated oil to one (or more) production wells. FIG. 9 shows the simple SF geometry using vertical wells. Usually the wells are arranged in regular patterns (e.g. FIG. 12 ). SF processes can recover more oil than CSS, but, one of the problems with SF processes is steam override, where steam rises to the top of the pay zone and breaks through to the production well, bypassing the heated oil bank. This can reduce productivity or even cause a premature abandonment of the process. If the reservoir dips, it is advantageous to arrange the wells so the steam injector is higher than the producer to take advantage of gravity drainage and to minimize steam override (e.g. California heavy oils).
[0079] One of the recent trends in SF is to consider the process, at least partially, as a gravity drainage process and manage heat input and production like SAGD (Green Car Cong. (2011). If this is done, recovery factors can approach 70-80%, similar to SAGD (ibid).
[0080] Horizontal wells are also being considered to improve productivity and recovery (Green Car Cong. (2011)). SAGD ( FIG. 2 ) can be considered as a vertical SF using gravity drainage as the dominant recovery mechanism (Butler, (1991)). Tangleflags, Sask. is an example of a vertical SF using a combination of vertical steam injectors and horizontal production wells ( FIG. 7 , Thomas (2008)). SF based solely on horizontal wells is also feasible ( FIG. 10 ).
[0081] Screening criteria for CSS and SF are similar (Table 2), but SF processes can recover more oil than CSS and SF has dominated world production for thermal EOR ( FIG. 1 ). Both CSS and SF have limitations in oil density (API>10), oil viscosity (μ<1000 cp.), depth (<5000 ft.), pay thickness (>20 ft.) and initial oil saturation (S 0 >0.50). But, many of these limitations are economic and were evaluated in an economic environment with low oil prices (<$30/bbl), so the screens may be outdated. They are not hard technical barriers. FIG. 6 shows thermal (steam) EOR is a medium-cost EOR process (Lake (1992)).
[0082] SF EOR began in the USA in the 1950-1960's (Lake (1992)) and the USA has continued as a dominant player ( FIG. 5 ). In 1998, California SF projects produced about 400 KBD using 20,000 vertical wells in the Bakersfield area (Stevens (1998)). Chevron is the largest US producer (Green, (2011)). The largest single SF project is the Duri field, operated by Caltex, in Indonesia, currently producing about 300 KBD (Jakarta Post (2011), FIG. 8 ). SF technology has also been introduced to the Mid East (heavyoilinfo (2010), Arabian Oil & Gas (2011)).
[0083] Some of the problems with SF include the following:
(1) SOR can be poor (higher than for SAGD). (2) Start-up may be difficult or prolonged because of injectivity limitations or lack of communication between injectors and producers. Often, SF is started by CSS. (3) Fracturing can also be an issue. if a fracture is formed, steam will flow in the fracture and transfer heat, by conduction, to surrounding oil. But, production will be slow because the steam is not driving the oil to the production well. (4) If the reservoir is too deep, heat losses are a concern. (5) Steam override is always an issue, unless we have a tilted reservoir with a gravity drive component. (6) Ultimate recovery, without gravity drainage, can still be poor (30 to 40% OOIP).
[0090] 2.3 Steam+Oxygen
[0091] COFCAW (combination of forward combustion and waterflood) is a version of an ISC process that injects water to produce steam in the reservoir. It produces a steam +oxygen (or air) mixture, upstream of the combustion front (Parrish (1969)). But, the process is a modified ISC process, not a modified SF process, and it is suited to a vertical well geometry, not to a horizontal well geometry. If liquid water is allowed to impinge on the combustion front, HTO will be quenched and either oxygen gas will break through to the production well or LTO oxidation will occur. LTO is undesirable because oxygen use is incomplete, heat release per unit oxygen consumed is less than HTO, and oxidation products include organic acids that can create undesirable emulsions that can cause reservoir blockages and/or oil/water (treating) separation problems.
[0092] When oxygen combusts in a hydrocarbon reservoir, the dominant, non-condensable gas produced is carbon dioxide. Steam+O 2 injected will produce steam+CO 2 in the reservoir. Several studies have looked at steam+CO 2 for CSS or SF EOR applications (Luo (2005), Frauenfeld (1988), Balog (1982)). There has also been some activity to produce steam+CO 2 or steam+flue gas mixtures using surface or down hole equipment (Balog (1982), Wylie (2010), Anderson (2010)). Steam+CO 2 generally has been shown to improve steam-only processes (CSS or SF). The incremental benefits of CO, may be reduced if the heavy oil already contains some dissolved gas (Frauenfeld (1988)). In some cases the improvement due to CO 2 was manifest in oil production rates, not in ultimate recovery (Leung, (1983)).
[0093] Activity based on steam+oxygen injection has been much less than steam+CO 2 . Laboratory combustion tube tests have been performed using mixtures of steam+oxygen (Moore (1994), (1999)). Combustion was very robust, showing good HTO combustion, even for very low oxygen concentrations in the mixture. The combustion was stable and more complete (less CO) than other oxidants (steam+air; air). Oxygen concentrations in the mix varied from under 3 to over 12% (v/v).
[0094] Yang (2008) (2009(1)) proposed to use steam+oxygen as an alternative to steam in a SAGD process. The process was simulated using a modified STARS simulation model, incorporating combustion kinetics. Yang demonstrated that for all oxygen mixes, the combustion zone was contained in the gas/steam chamber, using residual bitumen as a fuel. The combustion front never intersected the steam chamber walls. But, the steam/gas chamber was contained with no provision to remove non-condensable gases. So, back pressure in the gas chamber inhibited gas injection and bitumen production, using steam+oxygen mixtures. Also, there was no consideration of the corrosion issue for steam+oxygen injection in a horizontal well, nor was there any consideration of minimum oxygen flux rates to initiate and sustain HTO combustion using a long horizontal well for O 2 injection.
[0095] Yang ((2008), 2009(1)) also proposed an alternating steam/oxygen process as an alternative to continuous injection of steam+O 2 mixes. But, issues of corrosion, minimum oxygen flux maintenance, ignition risks and combustion stability maintenance, were not addressed.
[0096] Bousard (1976) proposed to inject air or oxygen with hot water or steam to propagate LTO combustion as a method to inject heat into a heavy oil reservoir. But HTO is desirable and LTO is undesirable, as discussed above.
[0097] Pfefferle (2008) suggested using oxygen +steam mixtures in a SAGD process, as a way to reduce steam demands and to partially upgrade heavy oil. Combustion was purported to occur at the bitumen interface (the chamber wall) and combustion temperature was controlled by adjusting oxygen concentrations. But, as shown by Yang, combustion will not occur at the chamber walls. It will occur inside the steam chamber, using residual bitumen as a fuel not bitumen from/at the chamber wall. Also, combustion temperature is almost independent of oxygen concentration (Butler, 1991). It is dependant on fuel (coke) lay-down rates by the combustion/pyrolysis process. Pfefferle also suggested oxygen injection over the full length of a horizontal well and did not address the issues of corrosion, nor of maintaining minimum oxygen flux rates if a long horizontal well is used for injection.
[0098] It is therefore a primary object of the invention to provide an enhanced oil recovery process for both steam flooding and cyclic steam stimulation wherein oxygen and steam are injected separately into a heavy oil reservoir.
[0099] It is a further object of the invention to provide at least one well to vent produced gases from the reservoir to control reservoir pressures.
[0100] It is yet a further object of the invention to provide oxygen at an amount of substantially 35% (v/v) and corresponding steam levels at 65%.
[0101] It is yet a further object of the invention to provide pipe sizes for CSSOX or SFOX wells that may be much smaller than for steam-only processes because oxygen carries about ten times the heat content, per unit volume.
[0102] Further and other objects of the invention will be apparent to one skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.
SUMMARY OF INVENTION
[0103] According to a primary aspect of the invention there is provided a process to recover heavy oil from a hydrocarbon reservoir, said process comprising injecting oxygen-containing gas and steam separately injected via separate wells into the reservoir to cause heated hydrocarbon fluids to flow more readily to a production well, wherein:
(i) the hydrocarbon is heavy oil (API from 10 to 20; with some initial gas injectivity) (ii) the ratio of oxygen/steam injectant gas is controlled in the range from 0.05 to 1.00 (v/v) (iii) the process uses Cyclic Steam Stimulation or Steam Flooding techniques and well geometry, with extra well(s) or a segregated zone to inject oxygen gas,
wherein the oxygen contact zone within the reservoir is less than substantially 50 metres long.
[0107] Preferably a separate well or segregation is used for non-condensable gas produced by combustion.
[0108] In one embodiment the oxygen-containing gas has an oxygen content of 95 to 99.9% (v/v).and preferably wherein the oxygen-containing gas has an oxygen content of 95 to 97% (v/v).
[0109] In another embodiment the oxygen-containing gas is air.
[0110] Preferably the oxygen-containing gas is enriched air with an oxygen content of substantially 20 to 95% (v/v).
[0111] In one embodiment the oxygen injection well within the reservoir is less than substantially 50 metres long proximate a steam swept zone.
[0112] Preferably the oxygen-containing gas injection step is started only after a steam-swept zone is formed around the injection point, preferably controlled by:
adjusting steam and oxygen flow ratios to attain a target. adjusting steam+oxygen flows to attain an energy rate target.
[0115] In a preferred embodiment a separate produced gas removal well is used to minimize steam override to production wells.
[0116] Preferably oxygen/steam (v/v) ratios start at about 0.05 and ramp up to 1.00 as the process matures.
[0117] In another embodiment the oxygen/steam (v/v) ratio is held between 0.4 and 0.7 and most preferably 0.35.
[0118] In a further embodiment the ratio of oxygen/steam (v/v) is between 0.4 and 0.7 and the oxygen purity in the oxygen-containing gas is between 95 and 97% (v/v).
[0119] In another embodiment the process further comprises an injector well (either a separate vertical well or the segregated portion of a well) having a maximum perforated zone (or zone with slotted liners) of less than substantially 50 m so that oxygen flux rates can be maximized.
[0120] Preferably Oxygen is injected proximate a steam-swept zone, whereby combustion of residual fuel in the reservoir is the source of energy for said combustion, said zone being preheated, at start-up, so spontaneous High Temperature Oxidation can occur.
[0121] According to yet another embodiment of the invention there is provided an improved Cyclic Steam Stimulation Enhanced Oil Recovery process to recover heavy oil comprising adding oxygen gas during a typical steam-injection cycle (the “huff”), the “soak” and “puff” cycles being similar to conventional CSS, wherein the injection of Oxygen provides extra energy from combustion of residual oil, for heavy oil recovery while creating CO 2 in the reservoir and removing produced CO 2 separately to better control the process.
[0122] Preferably an extra oxygen injection well is utilized.
[0123] Preferably the process further comprises segregating oxygen injection within steam injection wells using separate tubing and a packer.
[0124] Steam and oxygen are injected at separate times, as long as oxygen injection follows steam, so the reservoir is preheated for auto-ignition of High Temperature Oxidation combustion.
[0125] In one embodiment of the process oxygen injection is segregated near the top of the injector well or using a separate O 2 well, during the “huff” cycle, by injecting steam and oxygen; and during the “puff” cycle removing produced gases (mainly CO 2 ) separately to better control the process.
[0126] In a preferred embodiment the CSSOX process is the startup process for a SFOX process.
[0127] According to yet another aspect of the invention there is provided an improved Steam Flooding (SFOX EOR) process Enhanced Oil Recovery to recover heavy oil, basically similar to a conventional SF process, the improvement comprising injection of oxygen gas continuously injected near (or at) the steam injector to provide an added source of energy from in situ combustion of residual fuels, said Steam and oxygen being injected in a vertical-well geometry, with producer/injector wells arranged in regular patterns.
[0128] In a preferred embodiment separate wells are provided to remove non-condensable combustion gases.
[0129] Preferably the process further comprises use of horizontal wells, especially for the more viscous heavy oils.
[0130] In a preferred embodiment of the process the pipe sizes for CSSOX or SFOX wells can be much smaller than for steam-only processes because oxygen carries about ten times the heat content, per unit volume.
BRIEF DESCRIPTION OF THE FIGURES
[0131] FIG. 1 illustrates World EOR Production.
[0132] FIG. 2 illustrates the SAGD EOR Process.
[0133] FIG. 3 illustrates the CSS Process.
[0134] FIG. 4 illustrates an oil viscosity chart.
[0135] FIG. 5 illustrates USA/Canada Steam EOR.
[0136] FIG. 6 illustrates a cost comparison of EOR methods.
[0137] FIG. 7 illustrates Tangleflags steam flood.
[0138] FIG. 8 charts the Kern River, California and Duri, Indonesia SF projects.
[0139] FIG. 9 illustrates SF geometry.
[0140] FIG. 10 illustrates a horizontal well SF.
[0141] FIG. 11 illustrates a SFOX geometry.
[0142] FIG. 12 illustrates a 5-spot pattern for SFOX.
[0143] FIG. 13 illustrates well geometry for CSSOX 1.
[0144] FIG. 14 illustrates well geometry for CSSOX 2.
[0145] FIG. 15 illustrates residual bitumen in steam-swept zones.
[0146] FIG. 16 illustrates SFOX geometry.
[0147] FIG. 17 illustrates another SFOX geometry.
[0148] FIG. 18 illustrates CSSOX with produced gas removal.
DETAILED DESCRIPTION OF THE INVENTION
[0149] 3.1 Steam+Oxygen
[0150] If we inject steam and oxygen, in separate or segregated streams, into a heavy oil reservoir, we have two separate sources of heat. Oxygen will cause combustion of the residual heavy oil left behind by steam. As shown in FIG. 15 , we can expect residual heavy oil to be about 10% (v/v) (of pore space). This is sufficient to support and sustain combustion. Steam can transfer heat directly to the reservoir constituents from latent heat (heat released when steam condenses) or from sensible heat (heat transferred as hot condensate cools).
[0151] As previously discussed (2.3), there are two kinds of oxidation that can occur HTO (380-800° C.) where combustion produces mostly CO 2 , CO and H 2 O and LTO (150-300° C.) where combustion produces partially oxidized compounds including organic acids that can cause production difficulties. HTO is desirable and LTO is undesirable.
[0152] A convenient way to label steam+oxygen processes, for CSS or SF applications, is to consider the oxygen content in the steam+oxygen mix. (This doesn't imply that we inject a mixture or that we expect good mixing in the reservoir). Using this terminology, CSSOX (10) implies a 10% (v/v) oxygen concentration in a steam/oxygen mix used fora CSS application (CSSOX=CSS with oxygen). SFOX (10) implies the same mix used for an SF application.
[0153] Table 1 shows the properties of various steam+oxygen mixes, where we assume the heat release for oxygen combustion is 480 BTU/SCF (Butler (1991)) and we use an average steam heat content of 1000 BTU/lb. Because oxygen contains about 10 times the heat content of a similar volume of steam, as oxygen concentration in the mix increases, oxygen quickly dominates heat delivery. The transition point where oxygen heat=steam heat is for a mixture containing 9% (v/v) oxygen.
[0154] Mixtures of saturated steam and oxygen are very corrosive to carbon steel and other alloys (Zawierucha (1988)). Separate wells or a segregation system are needed. One suggestion (Yang (2009)) is to use a steam injector for alternating volumes of steam and oxygen. But, to sustain HTO combustion, we need a constant supply and a minimum flux of oxygen (Sarathi (1999)), otherwise oxygen will break through to production wells or LTO combustion may start.
[0155] It has also been suggested that we can simply inject mixtures of steam+oxygen and control corrosion using appropriate alloys or inhibitors (Yang (2009), Pfefferle (2008)) but this is difficult (Zawierucha (1988)). If a horizontal well is used as an injector, we have corrosion issues, and oxygen flux rates may be a concern. Oxygen flux is diluted over the length of the horizontal well. In some areas, oxygen flux may be too low to sustain HTO. Even if average flux rates are satisfactory, inhomogeneties in the reservoir may cause local oxygen depletions.
[0156] Oxygen needs to be injected into (or near to) a steam-swept zone, so combustion of residual fuel is the source of energy and injectivity is not a problem. The zone needs to be preheated, at start-up, so spontaneous HTO occurs.
[0157] There is a synergy between steam and oxygen for in situ EOR processes. Steam helps combustion by preheating the reservoir so auto-ignition can occur. In the combustion zone, steam adds OH and H radicals that improve (accelerate) and stabilize HTO combustion (ana)ogous to smokeless flare technology). Steam is an effective heat transfer medium to attain high productivity. Steam also increases combustion completeness (Moore (1994)). Oxygen helps steam by reducing steam/water demands per unit energy injected, generating extra steam by reflux, vaporizing connate water and producing steam directly as a product of combustion. Oxygen also increases energy efficiency. Oxygen adds CO 2 that can dissolve into heavy oil to reduce viscosity; providing dissolved gas drive recovery mechanisms. When non-condensable gases migrate to the top of the pay zone they will partially insulate the process from heat loss to the overburden, extending the economic limit (oxygen costs less than steam per unit heat delivered to the reservoir) to increase ultimate recovery. Lastly, if some CO 2 is retained in the reservoir, CO 2 emissions can be reduced.
[0158] 3.2 In Situ Combustion Chemistry
[0159] Oxygen creates energy in a heavy oil reservoir by combustion. The “coke” that is prepared by hot combustion gases fractionating and polymerizing residual heavy oil, can be represented by a reduced formula of CH 0.5 . This ignores trace components (S, N, O, . . . etc) and it doesn't imply a molecular structure nor a molecular size. It only means that the “coke” has an H/C atomic ratio of 0.5.
[0160] Let's also assume:
(1) CO in the product gases is about 10% of the carbon combusted (see Moore (1994)) for HTO. (2) Water-gas-shift reactions occur to completion in the reservoir—i.e. CO+H 2 O→CO 2 +H 2 +HEAT. This reaction is favored by lower T (lower than combustion) and by high concentrations of steam. The heat release is small compared to combustion.
[0163] Then, our net combustion stoichiometry is determined as follows:
[0164] Combustion: CH 0.5 +1.075O 2 →0.9CO 2 +0.1CO+0.25H 2 O+HEAT
[0165] Shift: 0.1CO+0.1H 2 O→0.1CO 2 +0.1H 2 +HEAT
[0166] Net: CH 0.5 +1.075O 2 →CO 2 +0.1H 2 +).15 H 2 O+HEAT
[0167] Features are as follows:
(1) heat release=480 BTU/SCF O 2 (Butler (1991)) (2) non-condensable gas make=102% of oxygen used (v/v) (3) combustion net water make=14% of oxygen used (v/v) (4) hydrogen gas make 9.3% of oxygen used (v/v) (5) produced gas composition ((v/v) %):
[0000]
Wet
Dry
CO 2
80.0
90.9
H 2
8.0
9.1
H 2 O
12.0
—
Total
100.0
100.0
(6) Combustion temperature is controlled by “coke” content and matrix properties. Typically, HTO combustion T is between (380-800° C.).
[0174] 3.3 CSSOX
[0175] The CSSOX EOR process to recover heavy oil is similar to CSS (previously described) but oxygen gas is added during the steam-injection cycle (the “huff”). The “soak” and “puff” cycles are similar to CSS. Oxygen provides extra energy from combustion, and creates CO 2 in the reservoir.
[0176] FIGS. 13 and 14 show how CSSOX can be conducted using an extra oxygen injection well or by segregating oxygen injection within the steam injection wells using separate tubing and a packer. Alternately, steam and oxygen can be injected at separate times, as long as oxygen injection follows steam, so the reservoir is preheated for auto-ignition of HTO combustion.
[0177] If we segregate oxygen injection near the top of the injector or using a separate O 2 well, as shown in FIG. 18 during the “huff” cycle we inject steam and oxygen; during the “puff” cycle we can remove produced gases (mainly CO 2 ) separately to better control the process.
[0178] 3.4 SFOX
[0179] The SFOX FOR process to recover heavy oil is similar to SF (previously described) but oxygen gas is continuously injected near (or at) the steam injector to provide an added source of energy from in situ combustion. Steam+oxygen are injected in a vertical-well geometry, with producer/injector wells arranged in regular patterns.
[0180] FIGS. 9 , 11 and 12 show how SFOX can be arranged. We can also use horizontal wells as shown in FIG. 10 , especially for the more viscous heavy oils.
[0181] The distinction between SF and SAGD process can sometimes be subtle. SAGD can be considered as a top-down steamflood, aided by gravity drainage. FIG. 7 shows an example of a hybrid process (SF and SAGD) where a vertical well is used as an injector and a lower horizontal well is used as a producer.
[0182] Gas (steam) override is an issue for SF processes. It may be advantageous in SFOX to include separate wells to remove non-condensable combustion gases as shown in FIG. 16 or to segregate production as shown in FIG. 17 . Gas volumes are small and these wells need not be large (Table 3).
[0183] 3.5 CSSOX/SFOX Advantages
[0184] Because, many times, a CSS project can be converted to a SF project, or CSS is deliberately used as a start-up process for SF; the advantages of the steam+oxygen version of each are similar—as follows, comparing CSSOX and SFOX to their non-oxygen cousins:
(1) Lower energy costs (per unit heat delivered to the reservoir, oxygen gas costs less than steam). (2) Reduced water use, per bbl. of production. (3) More energy injected per unit volume of injectant gas. Table 1 shows that and equal mix (v/v) of oxygen and steam contains over 450 percent more energy than pure steam. This can increase production rates. (4) Excess water production. A combustion process will mobilize connate water, in the combustion-swept zone, as steam. When produced, as water, this will contribute to an excess water production if all the injected steam is also produced as water. (5) Combustion also produces water directly as a product of hydrocarbon oxidation. (6) Carbon dioxide is produced by combustion. When CO 2 dissolves into periphery heavy oil, it will provide a dissolved-gas-drive mechanism and add to production and to ultimate recovery (Balog (1982), Luo (2005)). (7) Steam stimulates and helps HTO combustion (Moore (1994)). (8) Steam also causes combustion to be more complete—less CO more CO 2 . (9) If non-condensable gas is produced, it is mostly CO 2 and suitable for capture and sequestration. (10) For the same reservoir pressure, average temperatures will be higher. Oxidation or HTO combustion occurs at 380-800° C., much higher than saturated steam temperatures for typical reservoir pressures (1 to 4 MPa). (11) Up to a limit of oxygen injection, the heavy oil (residual coke) that is combusted is oil that would otherwise not be recovered (residual oil in the steam-swept zone). (12) Steam-only processes leave behind residual oil (about 10% of the pore space) Some of this oil is mobilized and recovered by the steam+oxygen processes. (13) If some of the combustion CO 2 is left-behind in the reservoir or if some of the produced CO 2 is captured and sequestered, CSSOX or SFOX can have reduced CO 2 emissions compared to their steam-only counterparts. (14) As shown in Table 3, because oxygen carries about ten times the heat content, per unit volume, pipe sizes for CSSOX or SFOX wells can be much smaller than for steam-only processes. (15) Table 3 also demonstrates for a wide range of oxygen+steam mixes, if we wish to deliver oxygen gas at a segregated section in an existing steam injector (e.g. FIG. 14 ), there is enough room for an oxygen tube and steam in the annulus, even for mixes as lean as 5% oxygen.
4 . Preferred Embodiments
[0200] 4.1 Heavy Oil
[0201] This invention applies to heavy oil with some initial oil mobility and initial gas injectivity. It does not apply to bitumen (API<10) that is better suited to the SAGD-version SAGDOX (in a separate patent).
[0202] For the purpose of this document we will define “heavy oil” as between 10 API and 20 API, with some initial gas injectivity in the reservoir.
[0203] 4.2 Separate Oxygen Injection
[0204] It has been suggested that EOR using a conventional SAGD geometry could be conducted by substituting an oxygen +steam mixture for steam (Yang (2009); Pfefferle (2008)). This is not a good idea for two reasons:
(1) Oxygen is different in its effectiveness compared to steam. Steam has a positive effect (adding heat) no matter how low the flux rate is or no matter how low the concentration. For oxygen to initiate and sustain the desired HTO combustion there is a minimum flux rate (Sarathi (1999)). This minimum rate is expected to depend on the properties of reservoir fluids, the properties of the reservoir and the condition of the reservoir. If oxygen flux is too low, either oxygen will break through, unused, to the produced gas removal well and/or the production well and/or remain in the reservoir, or the oxygen will initiate undesirable LTO reactions.
If oxygen is mixed with steam and injected into a long horizontal well (500 to 1000 m) the oxygen flux is dispersed/diluted over a long distance. Even if the average oxygen flux is suitable to initiate and sustain HTO combustion, heterogeneities in the reservoir can cause local flux rates to be below the minimum needed.
(2) Oxygen+steam mixtures are very corrosive particularly to carbon steel. The metallurgy of a conventional SAGD steam injector well could not withstand a switch to steam+oxygen mixtures without significant corrosion that could (quickly) compromise the well integrity. Corrosion has been cited as one of the issues for ISC projects that used enriched air or oxygen (Sarathi (1999)).
The preferred embodiment solution to these issues is to inject oxygen and steam in separate wells or at segregated points to minimize corrosion. Secondly, the injector well (either a separate vertical well or the segregated portion of well) should have a maximum perforated zone (or zone with slotted liners) of about 50 m so that oxygen flux rates can be maximized.
[0209] 4.3 Oxygen Concentration Ranges
[0210] Oxygen concentration in steam/oxygen injectant mix is a convenient way to quantify oxygen levels and to label processes (e.g. SFOX (35) is a process that has 35% oxygen in the mix). But, in reality we expect to inject oxygen and steam as separate gas streams without any expectations of mixing in the reservoir or in average or actual in situ gas concentrations. Rather than controlling “concentrations”, in practice would control to flow ratios of oxygen/steam (or the inverse). So SFOX (35) would be a SFOX process where the flow ratio of oxygen/steam was 0.5385 (v/v).
[0211] Our preferred range for CSSOX and SFOX has minimum and maximum oxygen ratios, with the following rationale:
(1) Our minimum oxygen/steam ratio is 0.05 (v/v) (oxygen concentration of about 5% (v/v)). Below this we start getting increased problems as follows:
(i) HTO combustion starts to become unstable. It becomes more difficult to attain minimum oxygen flux rates to sustain HTO, particularly for a mature SAGDOX process where the combustion front is far away from the injector. (ii) It also becomes difficult to vaporize and mobilize all connate water. (iii) Below 5% it is difficult to inject oxygen and steam in the same pipe, with a segregated oxygen tube, and maintain energy injection rates (see Table 3).
(2) Our maximum oxygen/steam ratio is 1.00 (v/v) (oxygen concentration of 50.0% (v/v)). Above this limit we start getting the following problems:
(i) Steam inventory in the reservoir drops to low levels, even with some reflux. (steam is the preferred fluid for heat transfer). (ii) The net bitumen (“coke”) fuel that is consumed by oxidation starts to exceed the residual fuel left behind in the steam-swept zone. (iii) Above this limit it becomes difficult (impossible) to produce steam and oxygen from an integrated ASU: Cogen plant. (iv) The oil cut in the production well increases and it may increase bulk viscosity and impair productivity.
[0221] So, the preferred range for oxygen/steam ratios is 0.05 to 1.00 (v/v) corresponding to a concentration range of 5 to 50% (v/v) of oxygen in the mix.
[0222] 4.4 Oxygen Purity
[0223] A cryogenic air separation unit (ASU) can produce oxygen gas with a purity variation from about 95 to 99.9 (v/v) % oxygen concentration. The higher end (99.0-99.9%) purity produces “chemical” grade oxygen. The lower end of the range (95-97%) purity consumes about 25% less energy (electricity) per unit oxygen produced (Praxair (2010)). The “contaminant” gas is primarily argon. Argon and oxygen have boiling points that are close, so cryogenic separation becomes difficult and costly. If argon and nitrogen in air remain unseparated, the resulting mixture is 95.7% “pure” oxygen.
[0224] For EOR purposes, argon is an inert gas that should have no impact on the process.
[0225] The preferred oxygen concentration is 95-97% purity (i.e. the least energy consumed in ASU operations) 4.5 Operation Strategy
[0226] In order to start oxygen injection as part of the CSSOX process or for the SFOX process we need to meet the following criteria:
(i) When oxygen is first injected, the injection point (well completion) is near to or inside a steam-swept zone, so we can minimize temperatures near an injection point, consume oil that would otherwise not be produced, and we have good gas injectivity. (ii) The reservoir where we wish combustion to occur has been preheated to about 200° C. so oxygen will spontaneously combust. (iii) The oxygen flux rate is high enough to initiate and sustain HTO combustion.
[0230] After we have achieved these conditions we can start CSSOX (in the “huff” cycle) or SFOX by:
(i) Start oxygen (and adjust steam) rates to achieve a target energy injection rate. (ii) Adjust steam and oxygen rates to achieve a target flow ratio. (iii) Monitor reservoir pressure and adjust rates or the ratio to achieve a target pressure. (iv) For SFOX, adjust production rates to control back pressure and/or to minimize steam losses or oxygen losses to gas override. (v) Also for CSSOX and SFOX, if we have a separate produced gas removal system ( FIGS. 16 , 17 , 18 ) controlling produced gas removal rate to minimize steam (gas) override to the production well(s).
5. CSSOX/SFOX Uniqueness
[0236] 5.1 Distinguishing Features of CSSOX, SFOX
(1) Utilizes simultaneous injection of steam and oxygen (2) Segregates oxygen injection (3) Has a preferred range of oxygen/steam (v/v) ratios (4) Recognizes synergy benefits of steam and oxygen (5) Has a preferred range of oxygen purity (6) May have separate wells to remove non-condensable gases produced by combustion (7) A procedure (criteria) to start up SFOX and CSSOX processes (8) A procedure to control/operate SFOX and CSSOX processes (9) Specific, proposed well geometries (10) Reduced water use compared to CSS or SF (11) Production of a “pure” CO 2 gas stream (12) With some CO 2 capture or sequestration, reduced CO 2 emissions compared to SF or CSS. (13) Can be added to existing SF or CSS processes (14) Compared to SF or CSS, SFOX or CSSOX produce less fluid for the same oil production. (15) Since oxygen is less costly than steam, CSSOX and SFOX projects can be run longer than CSS or SF with inherently extra reserves.
[0000]
TABLE 1
Steam + Oxygen Mixtures
% (v/v) Oxygen in Mixture
0
5
9
35
50
75
100
% heat from O 2
0
34.8
50.0
84.5
91.0
96.8
100
BTU/SCF Mix
47.4
69.0
86.3
198.8
263.7
371.9
480.0
MSCF/MMBTU
21.1
14.5
11.6
5.0
3.8
2.7
2.1
MSCF
0.0
0.7
1.0
1.8
1.9
2.0
2.1
O 2 /MMBTU
MSCF
21.1
13.8
10.6
3.3
1.9
0.7
0.0
Steam/MMBTU
Where:
(1) Steam heat value = 1000 BTU/lb (avg.)
(2) O 2 heat value = 480 BTU/SCF (Butler (1991))
(3) 0% oxygen = pure steam
[0000]
TABLE 2
Screening Criteria for SF EOR
φ
S 0
API
H (ft)
D (ft)
μ(cp)
F. Ali
.30
—
12-15
30
<3000
<1000
(1979)
Geffen
—
—
>10
>20
<4000
—
(1973)
Lewin
—
>.50
>10
>20
<5000
—
(1976)
Iyoho
>.30
>.50
10-20
30-400
2500-5000
200-1000
(1978)
Chu
>.20
>.40
<36
>10
>400
—
(1985)
Donaldson
>.20
>.40
10-36
—
<5000
<1000
(1989)
Where (1) the first 5 references are taken from Butler, 1991
(2) φ = fractional porosity
S 0 = original oil saturation
API = density (API scale)
H = net pay (ft.)
D = depth (ft.)
μ = viscosity (cp)
[0000]
TABLE 3
Steam + O 2 Pipe Sizes
% O 2 (v/v) in steam + O 2
0
5
9
35
50
75
100
Per
MMBTU
SCF
21.1
13.8
10.6
3.3
1.9
0.7
0
Steam
SCF
0.0
0.7
1.0
1.8
1.9
2.0
2.1
Oxygen
SCF
21.1
14.5
11.6
5.0
3.8
2.7
2.1
Total
Rel. pipe
Dia.
Steam
1
0.81
0.71
0.40
0.30
0.18
0
Oxygen
0
0.18
0.22
0.29
.30
.31
.32
Total
1
0.99
0.93
0.69
0.60
0.49
0.32
Where: (1) see also Table 1
(2) assumes same linear velocity in pipe
(3) volume rate capacity α square of diameter
(4) numbers may not add due to rounding
[0000]
TABLE 4
Canadian Steam EOR Production
Mar-(2011)
(kBD)
SAGD
Cenovus (Foster Creek)
118.7
Suncor (Firebag)
53.9
Devon (Jackfish)
31.8
Suncor (Mackay)
31.2
MEG (Christina Lk.)
27.1
Nexen (Long Lk.)
26.2
Conoco Phillips (Surmont)
22.3
Others
47.8
SAGD Total
359.0
CSS
Imp. Oil (Cold Lake)
162.0
Can Nat. (Primrose/Wolf Lk.)
77.2
Others
5.1
CSS total
244.3
Canada Total
603.3
Where - (1) First Energy Corp. Jun. 9, 2011.
[0252] As many changes therefore may be made to the embodiments of the invention without departing from the scope thereof. It is considered that all matter contained herein be considered illustrative of the invention and not in a limiting sense.
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A process to recover heavy oil from a hydrocarbon reservoir, said process comprising injecting oxygen-containing gas and steam separately injected via separate wells into the reservoir to cause heated hydrocarbon fluids to flow more readily to a production well, wherein:
(i) the hydrocarbon is heavy oil (API from 10 to 20; with some initial gas injectivity (ii) the ratio of oxygen/steam injectant gas is controlled in the range from 0.05 to 1.00 (v/v) (iii) the process uses Cyclic Steam Stimulation or Steam Flooding techniques and well geometry, with extra well(s) or a segregated zone to inject oxygen gas
wherein the oxygen contact zone within the reservoir is less than substantially 50 metres long.
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STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
BACKGROUND OF THE INVENTION
The present invention relates generally to signal distribution systems and more particularly to apparatus for distributing a time reference clock to all of the individual processors in an active aperture antenna array.
When digital processors are distributed over substantial distances, such that propagation time between elements is significant compared to processing time, then precise synchronization of all processing elements is required to assure their correct interaction. The path over which the synchronizing signals are broadcast must be carefully designed and the waveforms utilized should be selected to obtain the desired accuracy. In addition to operating all elements precisely in synchronism, there are sometimes special circumstances when the time reference must be precisely varied from element to element, for example to compensate for differential delays in signal paths. Such requirements are believed to be common to many applications where distributed processing is a characteristic.
One application which illustrates the magnitude and importance of the problem, is the active aperture antenna array. This array can comprise many thousands of individual radiating/receiving elements spaced over surfaces typically of a few hundred square feet. At each radiating element, a processor controls the phase of the RF signal to steer the antenna beam. The beam can be made extremely agile as the controlling processors are capable of switching in a few nanoseconds. With this agility, time sharing of the antenna to perform varied functions (such as multiple target tracking or communications) and ultra rapid scanning required in the bistatic radar pulse chasing mode, are possible. The beam steering mechanism is typically digitally based, and the transient condition between pointing in one direction and then moving to another direction, introduces disturbances which need to be minimized. These transients are particularly serious during bistatic pulse chasing where scan rates of the order of degrees per microsecond are possible. In this mode, signals are received while scanning by a step/dwell sequence. To minimize the impact of the disturbances created by stepping action, the ratio of times of stepping to dwell should be minimized. This can be accomplished by precise synchronization of the various processor elements.
The time of propagation of a signal in free space is about one nanosecond per foot and with typical antenna apertures of tens of feet, then transmission delays of tens of nanoseconds are possible. A pulse waveform for synchronization of the various processors to one or two nanoseconds will require a transmission path of several hundred megacycle bandwidth. A CW waveform however, occupies negligible bandwidth.
SUMMARY OF THE INVENTION
Accordingly it is a principal object of the present invention to provide an improved time reference clock distribution system.
A further object is to provide circuitry for distributing a time reference clock to all of the individual processors in an active aperture antenna array.
These and other objects of the present invention are achieved by a time reference or clock signal formed of two continuous wave sinusoidal waves of different frequency but of equal amplitude. The resulting composite waveform has sharply defined nulls occuring at the difference frequency which may be used as a precise time reference. By deriving the difference frequency from a stable clock source, the nulls in the composite waveform will be locked to the timing of the clock. Phase shift of one of the constituent sinusoidal waveforms relative to the other allows a vernier adjustment of the null to be set. A 180 degrees phase shift, for example, moves the null thru a time equal to one half of the null repetition interval.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the clock distribution circuit of the present invention; and
FIG. 2 is a block diagram of an alternate embodiment of the present invention including means for controlling the phase shift of the distributed timing signals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the selected application of the present invention illustrates the distribution of a time reference clock to all the individual processors in an active aperture antenna array. To simplify the illustration, a one dimensional array of only four radiating/receiving elements 2 is shown. Two dimensional arrays with four thousand elements, however, are more typical of today's designs. The radiating elements 2 typically are spaced at several inch intervals, with the entire row of say 100 elements being many feet long.
The source of timing signals is represented in FIG. 1 by a stable clock oscillator 4. A frequency f 1 of 10 MHz is assigned here for illustrative purposes. An RF oscillator 6, having a frequency f 2 say of 3,000 MHz, provides one of the two signals to be used to distribute the time reference. A phase locked oscillator 8 is driven by the stable oscillator 4 and the RF oscillator 6 so that it is phase locked to the sum of these two frequencies, f 1 +f 2 , that is 3010 MHz. Outputs from the RF and phase locked oscillators are added in a power adder 10 to give equal contributions in the resulting composite, two frequency, sum signal. A phase shifter 12 is located in the path of one of the two frequencies, and shown here in the path of frequency f 2 , permits vernier adjustment of the nulls in the sum signal relative to the phase of the stable clock oscillator 4. These relations can be expressed as follows:
Let stable oscillator 4 output be: sin (2πf 1 t+a)
Let RF oscillator 6 output be: sin (2πf 2 t+b)
Then phase locked oscillator 8 output is: sin (2π(f 1 +f 2 )t+a+b)
And the composite time signal is: 2 sin (π(2f 2 +f 1 )t+(a+2b)/2) cos(πf 1 t+a/2)
where the cosine term represents the envelope of the waveform, with nulls at the frequency of stable oscillator 4. The time of the nulls can be modified by changing the value of phase "a" in the cosine term in the last equation.
The network for distributing this two frequency waveform is illustrated in FIG. 1 as a pyramid of power dividers 14 resulting in equal fractions of the power of the time reference signal being delivered to all processors 16. In the design of the active array antenna, a distribution system of this type must already exist to distribute signals for transmission or to collect them during reception. The timing waveform may use these existing RF signal distribution paths if it does not interfere with the signal waveforms. The segregation or filtering of the timing waveform is made easy by its characteristics that are its insensitivity to the RF frequency at which it is set and its spectrum being two pure frequencies with no splatter outside of these spot frequencies.
The waveform comprised of two equal amplitude frequencies disclosed above is preferred for its simplicity. However many phase locked frequencies also could be added and their relative amplitudes controlled to give timing waveforms that are somewhat improved on the one disclosed. For example the null could be made sharper and hence the timing more precise. Another alternate with multiple frequencies is to so phase them as to create a periodic spike which would have a similar sharp rise time to that of the null. This spike waveform may, in some instances, be more suitable to use as a trigger than the waveform with a periodic null. Other applications that might utilize the novel clock signal distribution system described above are two dimensional antenna arrays, seismic or sonar arrays, and distributed processing in general.
A variant on the vernier control of the time pulse by phase changing one of the two RF constituents has an interesting application to array processing. If a signal arrives at the array from an angle not normal to the plane of array, then a wavefront of the signal will arrive at different times across the array aperture. It is often desirable to synchronize the processing at the element to the arriving wavefront. However, since signal sources may come from any direction, it is very desirable to rapidly modify the timing to suit the direction of arrival of a particular signal.
FIG. 2 illustrates how a well known method of controlling phase shift may be utilized to obtain the desired vernier increments of time reference delay over the entire array, to precisely match the time of arrival of off-axis signals. The time reference signal f 1 derived from stable clock oscillator 20 is side stepped in frequency by mixing in a signal mixer 22 with a variable frequency f 3 generated by a variable frequency oscillator 24. The mixer 22 output signal f 1 +f 3 is applied to a tapped delay line 25 consisting of delay line sections 26, 28 and 30. Output signals derived from taps 32, 34 and 36 of the delay line sections are mixed in mixers 38, 40 and 42 with the same variable frequency f 3 to recreate the frequency of the original time reference signal. However the phase carried by the reference signal f 1 at the inputs to the phase locked oscillators 44, 46, 48 and 50 now is advanced on that of the clock by an amount proportional to their respective time delays multiplied by offset frequency f 3 . The output frequency f 2 of free running oscillator 52 forms the second input for each of the phase locked oscillators 44, 46, 48 and 50 whose outputs are in turn applied to power adders 54, 56, 58 and 60 respectively together with a portion of the signal formed by free running oscillator 52 and power divider 62. It can be seen that increasing the offset frequency f 3 advances all phases t 1 , t 2 , t 3 and t 4 of the reference signal in proportion to the delay encountered in the delay line sections.
Although the invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.
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A system for communicating a time reference or clock signal to a plurality of processors over substantial distances where propagation time between units is significant compared to the processing time. The timing signal is in the form of two continuous sinusoidal waves of different frequency but equal amplitude, which are added to give equal contributions in the resultant composite, two frequency, sum signal. The resulting waveform has sharply defined nulls occurring at the difference frequency which are used as a precise time reference.
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FIELD OF THE INVENTION
[0001] This invention relates to waste disposal and more particularly, but not necessarily exclusively, to vacuum toilet assemblies preferably used in vehicles such as airplanes.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 6,401,270 to Moore, incorporated herein in its entirety by this reference, discloses a conventional hydraulic toilet in which positive pressure is used to facilitate discharging waste from a toilet pan or bowl. A closeable lid may be sealed to the bowl to define a chamber, with an air displacement unit connected to the chamber utilized to increase air pressure therein. The toilet of the Moore patent is not a vacuum type, however, and the Moore patent neither contemplates nor suggests means for reducing noise associated with operation of the toilet.
[0003] Unlike the Moore patent, U.S. Pat. No. to Olin, et al. (also incorporated herein in its entirety by reference) does detail a vacuum-type toilet. According to the Olin patent, operational noise of the toilet may be diminished through use of “a lid forming a substantially airtight and soundproof closure at the top of the bowl.” See Olin, Abstract, 11. 15-17. Air may be supplied to the toilet bowl via a tube or pipe entering at the back thereof if closing the lid results in too little air being present in the bowl for efficient flushing of waste. The Olin patent does not, however, address reducing water consumption in such a toilet design.
SUMMARY OF THE INVENTION
[0004] The present invention is intended to reduce both operational noise and water usage of a vacuum-type toilet while continuing to promote effective disposal of waste. It also allows for the amount of air per flush to be regulated compared to conventional vacuum toilets. In passenger aircraft, for example, reducing the amount of air required for toilet operation commensurately reduces the amount of cabin air necessarily replaced following use of the toilet. Because air has tendency to dry waste, using less air may also promote overall waste-system hygiene by reducing build-up of solids in waste-disposal piping.
[0005] Included as components of a toilet assembly of the present invention are a bowl having a rim and a shroud to which a lid is fitted. When closed, the lid is designed to seal against the upper surface of the shroud. Magnetic switches or other suitable means communicating with the flush mechanism may be used to ensure the lid is closed before the toilet is flushed.
[0006] Defined along the interior of the rim of the bowl may be a distribution “ring” at or through which both water and air may enter. Although preferably entering through separate openings in the distribution ring, the water and air combine upon entry into the bowl and are pulled through the bowl by evacuation thereof. Airflow pattern down the bowl face generates an “air knife” effect, which accelerates the water, in turn more efficiently removing waste from the bowl. This effect additionally reduces the overall amount of water needed to rinse the bowl effectively. In one presently-preferred embodiment, for example, only two and one half to three ounces of water may be needed for effective flushing.
[0007] Further, closing the lid and sealing it against the shroud reduces the amount of air entering the waste system via the bowl. Together with having air enter via the distribution ring under the shroud of the bowl, this sealing greatly reduces the noise associated with flushing the toilet. In a preferred embodiment, noise levels of less than eighty-four decibels have been achieved. For vehicle-mounted toilets, closing and sealing the lid also prevents flushing noise from reflecting off internal panels of the associated lavatory and escaping through door vents so as to disturb other passengers.
[0008] It thus is an optional, non-exclusive object of the present invention to provide improved vacuum-toilet assemblies.
[0009] It is another optional, non-exclusive object of the present invention to provide vacuum toilets which reduce air flow into the toilet bowl, require less water for effective flushing, and diminish the overall noise volume associated with flushing the toilets.
[0010] It is also an optional, non-exclusive object of the present invention to provide toilets in which lids seal with shrouds prior to flushing.
[0011] It is a further optional, non-exclusive object of the present invention to provide vacuum toilets having a distribution ring located along the rims of the bowls under the shrouds.
[0012] It is, moreover, an optional, non-exclusive object of the present invention to provide vacuum toilets in which both air and water enter the bowls via the distribution rings.
[0013] It is yet another optional, non-exclusive object of the present invention to provide vacuum toilets in which evacuation of the bowls produces an air-knife effect.
[0014] Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant field with reference to the remaining text and drawings of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a partially-schematicized view of an exemplary vacuum-toilet assembly of the present invention.
[0016] FIG. 2 is a cross-sectional view of a portion of the toilet assembly of FIG. 1 .
DETAILED DESCRIPTION
[0017] Illustrated in FIGS. 1-2 are aspects of toilet assembly 10 of the present invention. Included as part of assembly 10 may be toilet bowl 14 , flush valve 18 , and lid 22 . Additionally included may be shroud 26 , which in use typically surrounds the periphery of bowl 14 at or adjacent (and slightly above) rim 30 . Assembly 10 advantageously is of the vacuum type, in which waste is removed from bowl 14 by evacuating it. Assembly 10 additionally is especially designed for use in passenger aircraft, although it may function suitably in other vehicles, in buildings, or in other locations or objects as well.
[0018] Assembly 10 may include some or all of the valves, ducts, and other components described in the Olin patent. Beneficially, however, bowl 14 defines distribution ring 34 , preferably located within the bowl 14 at rim 30 . Both water and air may enter bowl 14 at ring 34 , promoting good mixing of the water and air upon entry into the bowl 14 .
[0019] Water may be supplied to bowl 14 in conventional ways, including via a pipe designed to discharge the water along ring 34 . Air preferably enters bowl 14 through at least one (and beneficially multiple) openings 38 through the wall of bowl 14 at rim 30 . Such openings 38 are below the level of shroud 26 , thereby limiting the amount of air available to them. Openings 38 are, however, at approximately the level of the water entering bowl 14 , allowing immediate mixing of the water and air at a point well above bottom section 42 of the bowl 14 .
[0020] Either or both of lid 22 and shroud 26 may include sealing material such as gasket 46 . Although any suitable sealing material or mechanism may be employed, gasket 46 functions to create an air-impervious seal between lid 22 and shroud 26 and prevent air from above shroud 26 entering bowl 14 through main waste-receiving opening 50 when the lid 22 is closed (as shown in FIGS. 1-2 ). Although not illustrated in FIGS. 1-2 , assembly 10 additionally may, if desired, comprise a magnetic switch or other mechanism designed to communicate with valve 18 and prevent flushing of bowl 14 unless lid 22 is closed. One such approach could employ a magnet placed in lid 22 and a corresponding magnetic switch placed under shroud 26 . Another example could include an automatically-closing lid 22 which could be activated via an infrared sensor or otherwise so as to be hands-free.
[0021] When assembly 10 is flushed, water and air enter bowl 14 at distribution ring 34 , are mixed, and are pulled toward bottom section 42 as bowl 14 evacuates. Air flow patterns across the interior face of bowl 14 generate an “air knife” effect, accelerating the flow of the water. Increased force applied to the water provides a more efficient way of removing waste within bowl 14 . This effect also reduces the overall amount of water needed to rinse bowl 14 effectively. Indeed, some embodiments of assembly 10 require only approximately two and one half to three ounces of water to flush satisfactorily, significantly less water than used by vacuum toilets currently employed on aircraft.
[0022] Because lid 22 is closed during flushing of assembly 10 , the amount of air pulled through bowl 14 during the flush may be regulated (depending on the number and size of openings 38 ). Further, because lid 22 is closed and air is pulled from areas below shroud 26 , the noise associated with the flush is substantially reduced. Although lid 22 is likely subjected to greater pressure than ambient (e.g. than aircraft cabin pressure) when assembly 10 is flushed, such pressure differential is only approximately two to four inches of mercury, within the stress capabilities of existing lids.
[0023] The foregoing is provided for purposes of illustrating, explaining, and describing exemplary embodiments and certain benefits of the present invention. Modifications and adaptations to the illustrated and described embodiments will be apparent to those skilled in the relevant art and may be made without departing from the scope or spirit of the invention.
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Vacuum toilet assemblies are detailed. These assemblies are designed to reduce both operational noise and water usage of the toilets while continuing to promote effective disposal of waste. They also require less air for operation than do conventional vacuum toilets.
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This is a continuation of International Appln. No. PCT/SE95/00467 filed Apr. 25, 1995.
FIELD OF THE INVENTION
The present invention is for a means and method for conveyance of individual objects. The invention further aims at sorting individual objects into common groups which objects may be e.g. books which have been returned to a library.
BACKGROUND OF THE INVENTION
Preferably the present invention is used together with a system which identifies the objects and thereupon controls the continued handling of them. Such a system may comprise that each individual object has been marked with a bar code which is read by means of an optical reader. The system generates signals which control the continued handling of the object.
The handling of certain types of objects, such as e.g. books, also brings with it special problems in order to avoid damages to the objects and by the unloading into collection cassettes since objects of very different shapes and sizes shall be handled.
SUMMARY OF THE INVENTION
One object of the present invention is to simplify this kind of handling and sorting of objects. Another object is to bring about a more simple and safe handling than by previously known means and devices for similar purposes.
In a first step the objects are identified by reading a bar code or in another suitable way. Thereupon each single object is transferred to a conveyor, by means of which the object is moved to and transferred to a suitable collecting device, e.g. a book cassette. In connection with the identification of the object there is also an updating of, for example a lending index and a signal is sent to an automatic control system so that the object is put into the correct cassette.
The invention will below be described more in detail with reference to the examples of embodiments of the invention shown in the enclosed Figures.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 shows in principle a device according to the invention.
FIG. 2 shows a device according to the invention as seen from the side.
FIG. 3 shows the device of FIG. 1 seen from above.
FIG. 4 shows the device of FIG. 1 partly in partial cross section as seen from one of its short ends.
FIG. 5 shows a side view of a preferred embodiment of the invention with a specially designed gripping device and conveying device.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows in principle an automatic handling equipment according to the invention which is intended to be used at a library to receive books which are returned and automatically sort them e.g. according to the classification of the book. Hereby each book which is returned shall on its outside have a marking with a bar code which according to the invention is used both to register that the book has been returned and to sort the book to the correct receiving cassette. The device comprises a returning table 15, having a scanner 35. In connection thereto there is a stand 3 with a conveyer which moves in the direction shown by arrows. Along the stand there are sixteen cassettes 24, 25 etc., into which returned books are sorted.
The function of the device is as follows. A conveyer 1 is built into the table 15, onto which returned books are placed. The conveyor belt is divided into sections by cross bars, and in each section one book is placed with the bar code facing upwards. The conveyer brings the returned book through the scanner 35, whereby the book is identified. A signal is then generated which is used by a control system of the device for the sorting of the returned book and a also signal which is used by the system to register the book as being returned and checking that the time for the loan has not been unduly extended. When passing through the identification device 35 each book is also centered on the conveyer e.g. by means of a pair of skewed or bent spring steel blades which press onto the sides of the book. In connection herewith a magnetic alarm strip in the back of the book may also be magnetized. The arrangement of the collection cassettes 24, 25 in connection to the conveyer is more closely shown in FIG. 4. Each cassette 24, 25 etc. is carried by a stand which seen from below slopes outwards from the conveyer. The cassette is movably arranged so that it can be raised at and lowered on the stand and its outer sides have been broken through so that the height of the pile of books in each cassette can be detected by means of a photoelectric cell or a similar device which is not shown in the Figure. When a cassette is empty it returns to its starting position which means that the lower level of the cassette is just below the level of a book which is returned so that this may slide into the cassette. The changed level of the pile of books in the cassette is automatically detected by the abovementioned photoelectric cell and the cassette is automatically lowered so that it is in the correct position to receive the next book. In this way the cassette is filled up and when it has been loaded full with books, it is automatically raised up to its upper position, by which the center of the cassette is slightly above the upper position of the stand. In this position the cassette may be tilted downwards - outwards from the conveyor, whereupon the cassette can be pulled in a direction from the conveyer and transferred e.g. to a carriage with a roller conveyor. On this carriage the cassette and the books are then brought to their position in the library.
The device shown in FIGS. 2, 3 and 4 comprises a conveyor with a conveyor band 3, onto which there are several plates 8, 9, 10, 11. The plates are mounted onto the conveyor belt 3 by means of a holder 12. The holder is such that the plates may be both turned and tilted. These functions are obtained e.g. by elctro-mechanical and electromagnetic means which do not form a part of the invention and are not shown in the Figures. In connection with the device there is a conveyor 1 for transportation of objects 2 which shall be sorted. The objects are sorted by being discharged to one of several collecting cassettes 24, 25 etc. which are arranged along the sides of the device. Books which have been returned are one at a time placed onto a conveyor belt 1. Hereby each book should be placed in a specified way so that each book has its back at the same direction and a bar code label or the like which is applied on the outside of the book is turned upwards. On the conveyor belt the book 2 is then brought through a device for reading of the code, whereupon the book is transferred to a plate 8 on the conveyor 3. The plate has the shape of flat disc having a protruding edge 14 along one of its sides. After the book has been placed on the plate this is tilted to the side so that the book slides down onto the edge 14. The movement takes place in a link 13 in the mounting 12. Thereupon the plate is returned to a horizontal position. At the same time or immediately in connection herewith the plate is moved and when it has reached a position at the cassette into which the book shall be returned the conveyor is stopped. The plate is turned 90 onto one side depending upon to which side the book shall be delivered. Preferably, the device is so designed that the turning movement takes place in the holder 12 above the link 13. The movement can be obtained e.g. by means of vertically movable rods, the position of which are controlled by the initially read bar code. Hereupon the book is delivered to the cassette by tilting of the plate in the direction towards the cassette. The tilting movement is also obtained in the link 13 of the mounting 12. Thereupon the conveyor 3 moves on and the plate returns to its starting position immediately or later before it returns to the point where another book shall be placed onto this plate.
In one embodiment of the invention the plate is mounted onto the mounting 12 so that the latter is the center of the plate in the direction of its movement when the plate is in a position for receiving of an object. The mounting is displaced along this line from the middle of the plate so that the center of its turning does not coincide with the center of the plate. When the plates are turned 90 to one side they will get into one of the positions which are shown by the plates 9 and 10 in FIG. 3. Herewith is achieved that the edge 14 of the respective plate is in or close to the extension of the side of each cassette 24, 25 etc. As seen from FIGS. 3 and 4, the cassettes of the two sides of the conveyor are differently turned. By the non-symmetric mounting of the plates, it is achieved that they after turning extend closer to the cassettes. This makes a correct delivery of the books easier and reduces the risks that books of different sizes shall meet edge to edge instead of being placed onto each other. By the delivery the respective plate is tilted downwards towards the receiving cassette and the book on the plate slips off therefrom supported along the edge 14. The different positions of the plate are also seen from FIG. 4, where a plate 8 having its supporting edge 14 in receiving position has been drawn by the full line. The displacement 15, 17 of the outer edges of the plates which takes place due to the turning and the displacement 16, 18 which after that takes place when the plates are tilted have been marked by broken lines. The cassettes 24, 25 are displaced in vertical direction, and their position in this direction is controlled by the height of the pile of books in each cassette. Photoelectric cells or other known technology is used for this purpose.
A preferred embodiment of the invention is shown in FIG. 5. In connection with the incoming conveyor 1 there is a roller conveyor 21 which slopes slightly downwards in a direction towards the pick-up lane and the collection cassettes. The roller conveyor ends by a stop being an edge 22. The book 2 waiting to be picked up for sorting onto a cassette rests onto the edge 22 and is centered by means of two rails, one on each side of the book in its lenghtwise direction. The rails are movable in a direction at right angle to the length of the book and the rails. The movement is suitably obtained by means of pneumatic cylinders. The pick up device comprises a lane 33 having a to-and-from movable conveyor belt 23. A pick up robot having a stand 26 and a bottom plate 27 follows with the movement of the band. The stand is movably arranged on the bottom plate and may bend forwards (to the left in the Figure) by moving in the link 28 which comprises an all-through extending shaft and may also be turned at least 90° to the right or to the left relative to the bottom plate. The forward movement is obtained by means of a pneumatic cylinder 30 which is mounted onto the arm 29, which is firmly connected to the stand, and flexibly mounted onto the stand. The turning movement is obtained by means of corresponding devices which are not shown in the FIGURE.
When a book 2 shall be picked up, the robot moves to a position where its gripping devices 31 and 32 extend over the book. The length of the book is indicated by means of a sensor 34 which is mounted onto a stand having the shape of a bow 35 over the roller conveyor 21. The gripping position for the gripping device varies relative to the length of the book so that if the book is short it is gripped by the outer end of the gripping devices but if the book is long the gripping devices extend further in over the book. The purpose of this is that when the book is positioned in a collecting cassette 24, 25 it shall be properly positioned relative to the back wall of the cassette. When the book has been gripped by the robot, this is moved to a position in at the selected cassette, whereupon the robot turns 90° to the right or the left and bends forwards so that the book enters the cassette and is released. The centering of the book which took place before it was picked up by the gripping device now brings with it that each book is positioned centered in the cassette. This can be essential to obtain a steady pile of books of different sizes.
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A transportation method of individual objects and a means for sorting each object into a receiver is disclosed. In accordance with the method, each object is individually picked from a conveyor and delivered to a selected collecting cassette, the objects being centered on the conveyor before being transferred to a pick-up device. The individual objects are delivered to the cassette with the pick-up device which turns 90 degrees and which tilts toward the selected cassette to deliver the object.
The apparatus for handling of the individual objects includes a conveyor, a pick-up device mounted to a conveyor belt intended to pick-up and move the individual objects, and a device for centering each object before transference to the pick-up device. The pick-up device is turnable by 90 degrees in each direction, and is tiltable in the direction of the object.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of one or more previously filed provisional applications identified as follows: Application Ser. No. 61/229,857 filed Jul. 30, 2009.
TECHNICAL FIELD
This invention relates to the field of exercise equipment and specifically to hand held weights in the form of dumbbells.
BACKGROUND OF THE INVENTION
Adjustable weight dumbbells are known that use an elongated, cylindrical bar as the handle. An inner collar is inset inwardly from each end of the bar with the collar being releasably fixed to the bar by some type of fastener or holding device. The inset provides a space on each end of the bar that is used to support one or more weight plates on the ends of the bar outboard of the inner collars. After the user stacks a desired number of weight plates on the ends of the bar, the user installs an outer collar on each end of the bar to hold the stacked weight plates on the ends of the bar to prevent the weight plates from sliding off the bar during exercise. The user adjusts the exercise mass of the dumbbell by changing the number of weight plates that are held between the inner and outer collars on each end of the bar. Typically, the weight plates are flat, circular plates having a central bore for slipping the weight plates onto the bar.
To use the dumbbell described above, the user merely grabs the center of the bar between the stacks of weight plates on the ends of the bar. Inherently, the user's hand is positioned centrally between the stacks of weight plates along a centerline of the bar, which is also a centerline of the stacked weight plates. The user can then lift and manipulate the dumbbell in any of the known ways to perform various weight training exercises, such as arm curls, arm presses, etc.
In the past, one manufacturer of dumbbells of the type described above has offered an optional U-shaped handle for converting this type of dumbbell to a kettlebell style. The bottoms of the spaced legs of the U-shaped handle were formed with circular bores that were designed to slide onto the bar that formed the usual handle for the dumbbell. The user would remove weight plates and the inner and outer collars from one end of the bar to provide access to the center of the bar. The user would then slip the U-shaped handle onto the bar from this end of the bar, namely the end of the bar from which the weight plates and collars had been removed, simply by telescoping or inserting the bores in the legs of the U-shape onto the bar and by then sliding the U-shaped handle inwardly to the center of the bar. The removed weight plates and collars could then be replaced onto the end of the bar from which they had been taken.
When so installed as described above, the U-shaped handle was captured between the inner collars on the bar. In addition, the legs of the U-shaped handle were long enough so that the base of the U-shaped handle, namely the connecting piece between the two legs of the handle, was positioned to be parallel to the bar but to be vertically displaced above the weight plates. Thus, the user could now grab the base of the U-shaped handle and swing or manipulate the dumbbell in the manner of a kettlebell. Thus, a standard adjustable weight dumbbell could be converted in this manner to a kettlebell type of exercise device.
Other adjustable weight dumbbells are known which are referred to as selectorized dumbbells, such as that shown in U.S. Pat. No. 5,637,034 as also shown in FIG. 1 of this application. In such a dumbbell, the handle is no longer a simple, cylindrical bar, but has a more complex shape. The handle of this type of dumbbell has a pair of planar ends that are spaced apart from one another but are rigidly joined to one another at least by a central hand grip that extends between the ends and is affixed thereto. In addition to the hand grip, there may be one or more cross tubes that also extend between and unite the spaced planar ends of the handle together. Some type of movable selector is used which coacts with the handle and with a desired number of weight plates disposed in left and right stacks of weight plates. When the selector is moved between different positions relative to the handle, different numbers of weight plates are coupled to the left and right ends of the handle to adjust the exercise mass of the selectorized dumbbell.
In a selectorized dumbbell of the type described above and as shown in FIG. 1 of this application, there is no way to use the U-shaped handle of prior dumbbells with the selectorized dumbbell to provide a kettlebell style of exercise. The U-shaped handle of the prior dumbbell is designed to slip onto a bar from which access can be had from one end of the bar. In the selectorized dumbbell, even if one considers the hand grip a bar, the ends of the hand grip are united to planar left and right ends of the handle thereby blocking access to the hand grip. There is simply no way to slide an auxiliary U-shaped handle onto the hand grip of the handle of the selectorized dumbbell as one is blocked from doing so by either the planar left end of the handle or the planar right end of the handle. It would be an advance in the art to provide some way of converting this type of selectorized dumbbell into a kettlebell type of exercise device.
SUMMARY OF THE INVENTION
One aspect of this invention relates to a selectorized dumbbell which comprises a plurality of nested weights comprising a stack of nested left weight plates and a stack of nested right weight plates separated by a gap. At least a first handle is provided with the handle having a hand grip extending along an axis with the handle further having opposite, substantially planar left and right ends that are rigidly joined to one another. The handle may be dropped down into the gap between the stacks of nested left and right weight plates such that the left end of the handle is adjacent an innermost left weight plate in the left stack of weight plates and the right end of the handle is adjacent an innermost right weight plate in the right stack of weight plates. A selector is movable into different positions relative to the handle and relative to the weight plates for coupling selected numbers of left weight plates to the left end of the handle and selected numbers of right weight plates to the right end of the handle. The hand grip of the first handle comprises an upwardly extending loop that is fixed at a bottom portion thereof between the left and right ends of the handle to join the left and right ends of the handle together and with the loop having a top gripping portion that is vertically positioned above the left and right ends of the handle and above top edges of the weight plates in the manner of a kettlebell exercise device.
Another aspect of this invention relates to a selectorized dumbbell, which comprises a plurality of nested weights comprising a stack of nested left weight plates and a stack of nested right weight plates separated by a gap. A handle is provided having a first hand grip extending along an axis with the handle further having opposite, substantially planar left and right ends joined to opposite ends of the hand grip with the left and right ends of the handle extending perpendicularly to the hand grip. The first hand grip of the handle extends substantially horizontally between top and bottom edges of the left and right ends of the handle such that the first hand grip of the handle will be located below top edges of the weight plates in the manner of a standard dumbbell. A selector is movable into different positions relative to the handle and relative to the weight plates for coupling selected numbers of left weight plates to the left end of the handle and selected numbers of right weight plates to the right end of the handle. A second hand grip is provided comprising a loop that is carried on the handle. The loop is movable relative to the handle between a first operative position in which a top gripping portion of the loop is vertically positioned above the left and right ends of the handle and above top edges of the weight plates in the manner of a kettlebell exercise device and a second non-operative position in which the top gripping portion of the loop is disposed between the left and right ends of the handle. The user can use the dumbbell in the manner of a kettlebell exercise device by moving the second hand grip comprising the loop into its first, operative position and by grasping the top gripping portion of the loop or in the manner of a standard dumbbell by disposing the top gripping portion of the loop in its second non-operative position and by grasping the first hand grip rather than the top gripping portion of the loop.
Yet another aspect of this invention relates to a selectorized dumbbell which comprises a plurality of nested weights comprising a stack of nested left weight plates and a stack of nested right weight plates separated by a gap. A handle is provided having opposite, substantially planar left and right ends that are rigidly joined to one another. The handle may be dropped down into the gap between the stacks of nested left and right weight plates such that the left end of the handle is adjacent an innermost left weight plate in the left stack of weight plates and the right end of the handle is adjacent an innermost right weight plate in the right stack of weight plates. The handle carries a pair or hand grips thereon comprising a first cylindrical bar type hand grip that in use is substantially horizontal and extends between the left and right ends of the handle and is disposed beneath top edges of the weight plates in the manner of a standard dumbbell and a second loop type hand grip that in use has a top gripping portion that that is vertically positioned above the left and right ends of the handle and above top edges of the weight plates in the manner of a kettlebell exercise device. A selector is movable into different positions relative to the handle and relative to the weight plates for coupling selected numbers of left weight plates to the left end of the handle and selected numbers of right weight plates to the right end of the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be described more completely in the following Detailed Description, when taken in conjunction with the following drawings, in which like reference numerals refer to like elements throughout.
FIG. 1 is an exploded, perspective view of a prior art selectorized dumbbell known as the PowerBlock®;
FIG. 2 is a perspective view of a first embodiment of a selectorized dumbbell that is convertible to a kettlebell configuration;
FIG. 3 is a perspective view of a second embodiment of a selectorized dumbbell having a dedicated kettlebell configuration;
FIG. 4 is an exploded, perspective view of the handle of the selectorized dumbbell of FIG. 3 ;
FIG. 5 is a partially exploded, perspective view of a handle of a third embodiment of a selectorized dumbbell that is convertible to a kettlebell configuration;
FIG. 6 is an operational, perspective view of the handle of FIG. 5 , particularly showing the kettlebell hand grip in a lowered, stowed position in which the kettlebell hand grip is not operational; and
FIG. 7 is an operational, perspective view similar to FIG. 6 , but showing the kettlebell hand grip in a raised, accessible position in which the kettlebell hand grip is operational.
DETAILED DESCRIPTION
A selectorized dumbbell of the type with which this invention can be used is shown as 2 in FIG. 1 . Dumbbell 2 is one of the PowerBlock® lines of dumbbells manufactured and sold by Power Block, Inc. of Owatonna, Minn. The details of such dumbbell 2 are disclosed in U.S. Pat. No. 5,637,034, assigned to the assignee of this invention, which is hereby incorporated by reference.
One characteristic of dumbbell 2 is the use of a plurality of nested weights 4 . Each weight 4 comprises a left weight plate 6 l , a right weight plate 6 r , and a pair of side rails 8 that hold weight plates 6 in a spaced apart orientation. Side rails 8 are attached in any suitable manner to the front and back edges of the pair of weight plates 6 that form one of weights 4 at the same vertical height along the front and back edges.
Weights 4 are nested in the sense that the left and right weight plates 6 l and 6 r in each weight 4 are progressively spaced apart slightly further from one another. Thus, all of the left weight plates 6 l are nested against one another in a set of nested left weight plates 6 l and all of the right weight plates 6 r are nested against one another in a set of nested right weight plates 6 r . Obviously, to make this happen, side rails 8 used in each weight 4 in a set of weights 4 have progressively longer lengths. Side rails 8 used in the innermost weight will be the shortest with side rails 8 then becoming progressively longer as required to space weight plates 6 in the other weights 4 progressively further apart. This is shown in FIG. 1 by the progressively longer lengths of side rails 8 proceeding from top to bottom.
A gap 12 is provided between the sets of nested left weight plates 6 l and nested right weight plates 6 r . A handle 14 can be dropped down into gap 12 . Handle 14 has a pair of opposite left and right ends 18 l and 18 r that are connected together by spacers or cross tubes 20 . The user can drop his hand down between the two upper cross tubes 20 to grip a hand grip 22 that extends between the ends 18 l and 18 r of handle 14 parallel to cross tubes 20 . Hand grip 22 fixedly connects to the laterally spaced ends 18 l and 18 r of handle 14 approximately at the centers of the ends 18 l and 18 r of handle 14 .
Each end 18 l and 18 r of handle 14 has a vertical array of slots 24 that traverse across the end 18 l and 18 r of handle 14 from the front to the back of handle 14 . Slots 24 are substantially horizontal grooves or shelves cut or formed into the ends 18 l and 18 r of handle 14 . Slots 24 are adapted to receive a pair of horizontal prongs on a selector 26 that is used to adjust how many weights are attached to handle 14 .
Once handle 14 has been inserted by the user in gap 12 , a desired number of weights 4 can be selectively coupled to handle 14 depending upon how selector 26 is positioned. If selector 26 is inserted into handle 4 beneath the lowermost side rails 8 , then selector 26 will pick up all weights 4 when handle 14 is lifted. Moving selector 26 up will pick up fewer weights to thereby adjust the exercise mass carried by handle 14 . Essentially, only those weights 4 whose side rails 8 are above the location of selector 26 will be coupled to handle 14 .
FIG. 2 shows a first embodiment of a dumbbell 2 according to this invention. In this embodiment, a handle 14 like that shown in FIG. 1 is used except that the usual dumbbell style hand grip 22 has been replaced with a kettlebell hand grip 28 . Kettlebell hand grip 28 will be fixedly secured in any suitable manner to each end 18 l and 18 r of handle 14 in place of dumbbell hand grip 22 . Kettlebell hand grip 28 includes an upwardly extending loop 30 that protrudes above weights 4 in the manner of a kettlebell exercise device. Thus, the user can grip loop 30 and lift and swing dumbbell 2 in the manner of a kettlebell.
It would be possible for dumbbell hand grip 22 and for kettlebell hand grip 28 to each be removable and replaceable from within handle 14 , e.g. by unbolting or unscrewing one hand grip and by then installing the other hand grip. Thus, one would convert dumbbell 2 from its traditional dumbbell use to kettlebell use by swapping out just the hand grip portions 22 or 28 of handle 14 . However, it would also be possible to sell and for a user to purchase two complete handles 14 , one with a dumbbell hand grip 22 and the other with a kettlebell hand grip 28 , with the user simply using whichever handle 14 that he or she desires at any given time. This latter alternative is attractive because the user does not have to bolt or unscrew anything to make the conversion. All the user has to do is pick up whichever handle 14 that has the hand grip style the user wishes to use and then drop that handle down into gap 12 of dumbbell 2 .
FIGS. 3 and 4 show a second embodiment of a dumbbell 2 according to this invention. This embodiment is a dedicated kettlebell style of dumbbell 2 in which the gap 12 in the nested weights 4 is narrowed so that it is no longer wide enough to accommodate a user's hand, i.e. it is no longer possible to use a dumbbell hand grip 22 in gap 12 . The only way for a user to use dumbbell 2 as shown in FIG. 4 is in the manner of a kettlebell. Thus, handle 14 includes only a kettlebell hand grip 28 ′ with a loop 30 ′ protruding up above weights 4 .
As shown in FIG. 4 , handle 14 in this embodiment includes the ends 18 l and 18 r , but such ends 18 l and 18 r are now spaced apart far enough simply to receive a mounting flange 32 on kettlebell hand grip 28 ′. In effect, flange 32 is tightly sandwiched and clamped between ends 18 l and 18 r when such ends are bolted or screwed together. Loop 30 ′ of kettlebell hand grip 28 ′ is fixed atop flange 32 as shown in FIG. 4 . Ends 18 l and 18 r of handle 14 can be brought so close together in this embodiment since this version of dumbbell 2 is not designed to function as a normal dumbbell with the user's hand between the spaced weight plates 6 , but only as a kettlebell.
Kettlebell hand grips 28 , 28 ′ as shown in the embodiments of FIGS. 2 and 3 have the loops 30 , 30 ′ thereof extending parallel to the axes of side rails 8 . Loops 30 , 30 ′ could also be swung around 90° relative thereto to extend perpendicularly to the axes of side rails 8 .
Handle 14 for a third embodiment of a dumbbell 2 according to this invention is shown in FIGS. 5-7 . This embodiment of dumbbell 2 will use a traditional set of nested weights 4 from the PowerBlock® dumbbell as shown in FIGS. 1 and 2 , namely where a normal sized gap 12 is provided such that a full sized handle 14 can be dropped into gap 12 . However, for the sake of clarity, the set of nested weights 14 is not shown in FIGS. 5-7 . Only the handle 14 is depicted.
Handle 14 of the third embodiment of dumbbell 2 has all the characteristics of the usual handle for a PowerBlock® dumbbell, namely spaced left and right ends 18 l and 18 r , upper cross tubes 20 and a dumbbell hand grip 22 . However, in this embodiment, handle 14 includes a kettlebell hand grip 28 ″ forming a loop 30 ″ that is installed on handle 14 and is carried with handle 14 in addition to dumbbell hand grip 22 . Kettlebell hand grip 28 ″ is selectively movable on handle 14 between a lowered, stowed position and a raised, accessible position. In the lowered, stowed position thereof as shown in FIG. 6 , loop 30 ″ is located towards the bottom of handle 14 between the left and right ends 18 l and 18 r of handle 14 and cannot be gripped or used by the user since it will normally be obstructed by side rails 8 of weights 4 . In the raised, accessible position thereof as shown in FIG. 7 , loop 30 ″ is located above all the weights 4 in a position where the user can grip kettlebell hand grip 28 and swing and use weights 4 in the manner of a kettlebell.
Kettlebell hand grip 28 ″ is U-shaped with loop 30 ″ being formed by the U-shape. Kettlebell hand grip 28 ″ has a pair of aligned circular openings 34 in the ends of the legs thereof. This allows kettlebell hand grip 28 ″ to be pivotally mounted on one of the cross tubes 20 of handle 14 . The pivoting action of hand grip 28 ″ around cross tube 20 , as indicated by arrow A in FIG. 6 , is what permits movement of hand grip 28 ″ between the lowered, stowed position thereof and the raised, accessible position thereof. Such pivoting movement will be performed by the user when handle 14 is not inserted within the gap 12 of nested weights 4 in order that such movement not be obstructed by side rails 8 .
A detent or lock mechanism is provided in handle 14 to securely hold kettlebell hand grip 28 ″ in its lowered, stowed position or in its raised, accessible position. Such detent or lock mechanism comprises spring biased pop pins 36 that are received in sockets 38 beneath cross tube 20 in each 18 l and 18 r of handle 14 . See FIG. 5 . Only one socket 38 is shown in FIG. 5 in end 18 r since the corresponding socket in end 18 l is hidden. Each pop pin 36 cooperates with one of a series of holes 40 located in the legs of hand grip 28 ″ with holes 40 surrounding openings 34 on a diameter that allows each hole 40 to register with pop pin 36 . When a hole 40 is brought over and is aligned with pop pin 36 by virtue of pivoting motion of hand grip 28 ″, the internal spring bias on pop pin 36 will cause the head of pop pin 36 to extend and be received in a locking engagement with the hole. The spring force that biases pop pin 36 into such locking engagement is strong enough to hold hand grip 28 ″ in a desired position thereof during use of dumbbell 2 , but is not so strong that it cannot be overcome by the user providing manual force on hand grip 28 ″ to pivot hand grip 28 ″ around cross tube 20 .
One hole 40 a is located on one side of opening 34 and is effective to lock hand grip in its lowered, stowed position as shown in FIG. 6 . Three holes 40 b , 40 c , 40 d spaced apart in increments of 30° or so are provided on the opposite side of opening 34 . One such hole 40 b , 40 c , 40 d is used to receive pop pin 36 and lock hand grip 28 ″ in its raised, accessible position. When middle hole 40 c is used as shown in FIG. 7 , hand grip 28 ″ and loop 30 ″ thereof extend straight up from cross tube 20 . If holes 40 b or 40 d are used, hand grip 28 and loop 30 ″ will extend upwardly in an inclined fashion tilting either outwardly or inwardly, respectively, with respective to cross tube 20 . The series of holes 40 b - 40 d allows the user to select whatever specific position of hand grip 28 ″ is most comfortable to him or her when using kettlebell hand grip 28 to exercise with dumbbell 2 in the manner of a kettlebell.
The embodiment of dumbbell 2 shown in FIGS. 5-7 is advantageous because it allows a user to quickly and easily convert dumbbell 2 from use as a traditional dumbbell to use as a kettlebell. Only a single handle 14 need be purchased and used by the user. To convert dumbbell 2 into kettlebell use, the user need only lift handle 14 out of gap 12 until it clears the nested weights 4 and then grip kettlebell hand grip 28 ″ and swing it upwardly from the position shown in FIG. 6 to the position shown in FIG. 7 . The user can dispose hand grip 28 ″ either straight up and down as shown in FIG. 7 or can incline it inwardly or outwardly depending upon which one of the holes 40 b - 40 d is used to receive pop pin 36 . Then, the user simply drops the converted handle 14 back down into the gap 12 of the nested weights and positions selector 26 to pick up whatever number of weights the user wishes to use. When the user picks up handle 14 again, he or she can pick it up using the now raised and accessible kettlebell hand grip 28 ″ and the selected number of weights will rise with handle 14 for use as the exercise mass in a kettlebell style of exercise.
Various modifications of this invention will be apparent to those of skill in the art. Accordingly, the scope of this invention is to be limited only by the appended claims.
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A selectorized dumbbell has nested stacks of left and right weight plates, a handle that can be disposed between the two stacks of weight plates, and a selector that couples selected numbers of the left and right weight plates to left and right planar ends of the handle. The handle has at least one loop type hand grip located above the ends of the handle and above the weight plates to allow the dumbbell to be used as a kettlebell. This loop type hand grip can be replaced with a bar type hand grip if the dumbbell is to be used like a standard dumbbell, or the handle can be provided in kettlebell or standard versions thereof. Alternatively, the loop type hand grip can be movably disposed on the handle for movement between operative and non-operative positions.
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RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/185,202, entitled “System and Method for Targeting Network Devices for Content Deployment”, by Chaitanya Kanojia, Lee Kamenstky, Peter Hall, and Ian Copeman, filed on Feb. 25, 2000, the entire teachings of which is incorporated herein by this reference.
BACKGROUND OF THE INVENTION
Generally, under the current state of technology and in the past, television has been delivered to the residential home either through radio-frequency broadcasts, satellite downlink, or over coaxial cable television (CATV) network. Data network communications, such as Internet access, have been delivered via the telephone networks through dial-up connections, ISDN (Integrated Services Digital Network), and DSL (Digital Subscriber Line) lines or over hybrid broadcast/data CATV networks, where a portion of the bandwidth transmitted by the coaxial cable is allocated for shared data network functionality using a CSMA/CD-style transmission protocol. Less commonly, data connections to the home are provided via satellite links where data are downloaded via the satellite link and uploads are handled through land lines, such as the telephone network. Another technique is to transmit data to the home via wireless, CAMA, for example, links.
Almost universally, the clients or network devices in the residences are personal computers. Typically, they execute application programs such as email clients and browsers that utilize the data network connectivity offered by one of the above techniques.
The trend, however, is towards a more ubiquitous computing model where the network devices in the home will be embedded systems designed for a particular function or purpose. This has already occurred to some degree. Today, for example, CATV network set-top boxes typically have limited data communication capabilities. Their main function is to handle channel access issues between residential users and a server on the cable TV network.
In the future, the functionality offered by these set-top boxes or other embedded platforms, such as a game system, will be expanded. For example, they may offer Internet browsing capabilities and e-commerce serving capabilities. Moreover, it is anticipated that common-household appliances will also have network functionality, in which they will be attached to the network to automate various tasks.
The data networks must evolve with deployment of these embedded systems. Where the personal computer can be updated with new network drivers as the network evolves, embedded client systems remain relatively static. Moreover, the process of installation in the residence must be made less complicated so that a network technician is not required every time a new embedded device is connected onto the network.
SUMMARY OF THE INVENTION
Previously, techniques have been developed that allow information to be downloaded to a television or set-top box. For example, under the standards established by the Advanced Television Enhancement Forum (ATVEF), HTML can be embedded in a video signal. Many previous systems have enabled information to be inserted into the vertical blanking interval of a video signal.
The problem is that these techniques are broadcast-based—with the same content being transmitted to all the devices that receive the video signal. They can not target users with specific attributes. In addition, these techniques require sophisticated video editing to insert information into the video signal.
The present disclosed system is directed toward a communication and management system that can dynamically targets network devices for content deployment, such as application programs, device drivers, configuration files, and registry subhives. Moreover, the present system targets users of network devices for promotions, such as advertisements offered by Internet, or other network, e-commerce sites. Promotions are generally icons or graphic images with links to host web servers overlaying a video display, but also includes audio and video clips or data streams.
Network devices and their users are targeted through user profiles. User profiles are created when network devices register with the system server and are continually updated with information provided by user activity and event logs that are periodically uploaded from each device.
The present invention implements a scalable messaging system for data transmission between the system server and among the network devices such that it is neutral as to the specific hardware platforms on which it is implemented.
One area of interest concerns the deployment (i.e. download and installation) of content to the network devices.
In general, according to one aspect, the present invention concerns a system for deploying content to targeted network devices over a data network. The system comprises a content store that stores the deployable content. A system manager then schedules the download of the content from the data store to targeted network devices.
Further, the system manager delivers criteria, set by the system administrator, for the activation of that content on the network devices. In this way, the present invention avoids the need to universally broadcast the content. It is downloaded, installed, and then activated based on specific criteria. As a result, a system constructed according to these principles allows for targeted deployment of the content. This content, then residing on the network device, is activated in response to established criteria.
In specific embodiments, the system manager selects targeted network devices among all of the network devices in response to profile information associated with those network devices. For example, the content can be targeted for deployment only to network devices in homes meeting predefined financial criteria.
Moreover, the deployment of content can be scheduled during off-peak periods of network activity. For example, during the early morning hours, data network activity is generally low and an optimal time for deployment. In other embodiments, the server system can actually monitor the network for periods of low network usage and schedule deployment during such periods.
In the preferred embodiment, a bulk data manager has access to the content store. It communicates with a bulk data transfer agent, executing on the network device, to move the content from the server system to the specific network device.
Once content is deployed, various types of activation criteria can be employed. Scheduled activation and event driven activation are two such methods of activating content at the network devices.
Scheduled activation includes activating content in response to a predetermined date and time as well as activation via start messages from the system server.
Event driven activation includes activating content based on the occurrence of events specified in an event map, such as channel events.
In the case of promotions, event driven activation also includes the activation of promotions triggered by HTML tags, or other triggers, embedded in a video signal.
In general, according to another aspect, the invention can also be characterized in the context of a method. The invention, in general, concerns a method for deploying content to network devices over a data network. This method comprises storing content on content store of a server system. The content is then scheduled for deployment from the system server to targeted network devices. Activation criteria is also downloaded to those targeted network devices.
The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:
FIG. 1A is a schematic block diagram depicting a cable network infrastructure in which one embodiment of the present invention functions.
FIG. 1B is a schematic block diagram depicting a satellite network infrastructure in which another embodiment of the present invention functions.
FIG. 1C is a schematic block diagram depicting a Digital Subscriber Line (DSL) network infrastructure in which still another embodiment of the present invention functions.
FIG. 1D is a schematic block diagram depicting a wireless network infrastructure in which another embodiment of the present invention functions.
FIG. 2A is a block diagram depicting the interaction of the components of the server system and the embedded client system according to the invention.
FIG. 2B is a process diagram illustrating the interaction between a queue manager and the message router according to the invention.
FIG. 2C is a process diagram illustrating a process for delivering a message via the message router according to the invention.
FIG. 3 is a state line diagram illustrating a process for automatically registering a device and generating user profiles for targeting content according to the invention.
FIG. 4A is a state line diagram illustrating a process for targeting consumers with content (e.g., graphical promotion) and deploying the content to a targeted device according to the invention.
FIG. 4B is a process diagram illustrating a process for scheduling activation of content with a predetermined date and time according to the invention.
FIG. 4C is a process diagram illustrating a process for scheduling activation of content by server activation according to the invention.
FIG. 4D is a process diagram illustrating a process for event driven activation of content according to the invention.
FIG. 4E is a block diagram depicting event driven activation involving trigger signals in the video stream according to the invention.
FIG. 5A is an example of the Document Type Definition used to define the document structure of the user activity and event logs written in XML (Extensible Markup Language) according to the invention.
FIG. 5B is an example of the representation of events stored in a user activity and event log written in XML according to the invention.
FIG. 6 is a state line diagram illustrating a process for automatically for updating user profiles through uploading and parsing user activity and event logs according to the invention.
FIG. 7 is a process diagram illustrating a process for dynamically installing a driver on a network device according to the invention.
FIG. 8 is a flow diagram showing the uninstallation of the driver on the network device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a communications and management system executing over a data network for targeting content, including promotions, to users of network devices whose attributes match the attributes of a group profile along with maintaining those network devices.
The system and methods of the present invention can be implemented over a variety of data network infrastructure including cable, satellite, Digital Subscriber Lines (DSL), and wireless networks.
FIG. 1A shows one embodiment of the present invention in which the communications and management system is implemented over a cable network. In this environment, audio and video broadcasts are typically frequency multiplexed with data transmissions on the coaxial cables extending from the head end 50 to the exemplary network devices 80 A, 80 B, 80 C, and 80 D (collectively referred to as 80 ).
Video content providers 20 as well as Internet content providers 10 (i.e. host web servers) deliver their audio/video/data signals to a cable service provider/internet service provider (CSP/ISP) data center 40 . The Internet content providers 10 deliver their data to the data center 40 via the Internet 30 . Typically, video content providers 20 transmit their video signals to the data center 40 via some broadcast medium, such as conventional radio-frequency television broadcasting techniques, or via a digital satellite downlink.
The CSP/ISP data center 40 transmits the audio/video/data signals to multiple head ends 50 (only one being shown for simplicity of illustration). The connection between the data center 40 and the head end 50 is typically a hybrid CATV/data connection, which is supported by an optical fiber infrastructure. Part of this infrastructure carries the audio/video signals, which are directed from the data center 40 to the network devices 80 . Part of this network also carries the bi-directional data communications associated with network control and internet service provisioning.
The head end 50 distributes the audio/video/data signals over a cable network of hubs 60 and local nodes 70 to a variety of network devices 80 , such as set-top boxes, web phones, and cable modems. Some network devices 80 D, such as a web phone, have a built-in video display 310 and speaker system 315 . Other network devices 80 C are peripherally attached to a video display device and speaker system such as a television 300 .
In one embodiment of the present invention, the server system ( 100 A and 100 B, collectively referred to as 100 ), is located at the CSP/ISP data center 40 and the head end 50 of the cable network. Installation of the server system at the data center 40 and the head end 40 allows for scalability. The server system 100 A at the data center 40 typically provides centralized management for configuring group profiles and content deployment options, while the server system 100 B at the head end 50 preferably handles the registration, user profile updates, content deployment, and other services among the network devices 80 .
There are alternative schemes for deploying the server system 100 within the cable network infrastructure depending on the capacity of the server system 100 and number of network devices 80 . For example, the server system 100 is deployed at the hub 60 level when the population of devices is sufficiently dense to necessitate such distribution of the communication load.
FIG. 1B shows an embodiment of the present invention in which the communications and management system is implemented on a satellite network. In this environment, the server system 100 is located at data center 45 .
The server system 100 transmits data to the network devices 80 via a satellite uplink device 90 to a satellite 93 , which, in turn, transmits the data to a residential satellite downlink dish 95 . The data are received by the network devices 80 connected to the downlink feed 97 .
For the return, upload, path, the network devices 80 transmit data to the server system 100 through a built-in modem, other dial-up device, or a land line system such as ISDN or DSL. The modem connects to a central office or point-of-presence (POP) 55 , which, in turn, transmits the return-path data over the Internet 30 to the data center 45 .
FIG. 1C shows an embodiment of the present invention in which the communications and management system is implemented on a Digital Subscriber Line (DSL) network. In this environment, the server system 100 is located at data center 45 .
The server system 100 communicates bi-directionally with the network devices 80 via the Internet 30 or closed network connection, such as frame-relay, to a central office or point-of-presence (POP) 55 . In one embodiment, the Internet connection between the server system 100 and the central office 55 is over a Virtual Private Network (VPN) providing a private, secure, encrypted connection tunnel.
The network devices 80 are connected to the Internet 30 by the central office 55 via Digital Subscriber Lines (DSL).
FIG. 1D shows an embodiment of the present invention in which the communications and management system is implemented on a wireless network. This environment is similar to the DSL network with the exception that the network devices 80 are connected to the Internet 30 by the central office 55 via wireless, typically CDMA, connections.
FIG. 2A shows the organization of the server system 100 and the embedded client system 200 interacting to implement the communications and management system.
In brief overview, the server system 100 includes a management console 110 , a system manager 120 , a data store 130 , a queue manager 140 , a message router 150 , a bulk data transfer manager 160 , and an XML file processor 170 . The embedded client system 200 executing in the network devices include a web browser 210 , a system agent 220 , a promotion notification agent 230 , a queue manager 240 , a logging agent, 250 , and a bulk data transfer agent 260 .
In more detail, the management console 100 is preferably implemented as a web server. In one embodiment of the present invention, the management console 100 is a Microsoft® Internet Information Server (IIS) implementing Active Server Pages (ASP).
The management console 100 provides, upon request by a system administrator, a web page interface for specifying the content to deploy, the attributes of a group profile that target a market segment of potential consumers, installation information, and criteria for activating the content or displaying the promotions at the network devices. Upon submitting the web page, the management console 100 communicates with the system manager 120 , via an Application Programming Interface (API) to store the targeted group profile, activation criteria, and the content and promotions to the data store 130 . In one embodiment the API is a Microsoft® COM interface.
Content includes, but is not limited to, applications, device drivers, data files, registry sub-hives, and promotions. Promotions are a special type of content that advertise goods and services. Promotions overlay the video display of a network device with a graphic, image, or animated icon that launches a web browser to a host web server in response to the user clicking or selecting it. Promotions also include audio and video clips or data streams. One or more promotions can be displayed on the video display at one time.
The management console 110 also provides a web page interface to users upon request during the initial registration of their network devices. Users will register through the web page interface, providing data about themselves. Upon submitting the web page, the management console 110 communicates with the system manager 120 , via the COM interface, to store the user data as attributes of a user profile. The attributes of the user profile are associated with the attributes of the group profile in order to target potential consumers who would be interested in the content or promotions.
The system manager 120 is an application-level process that manages the reading and writing of data to the data store 130 . The system manager 120 , through its COM interface, allows the management console 110 to store user profiles, content including promotions along with associated group profiles, installation information, and activation criteria. In addition, the system manager 120 updates the user and group profiles whenever new attributes are received.
The system manager 120 also interacts with the system agent 220 of the targeted network devices by sending and receiving messages through a messaging protocol. The interaction of the system manager 120 and the system agent 220 implement the scheduling of content deployment as well as installation and activation of the content. In one embodiment, the system manager is implemented as a Microsoft® COM object.
The queue manager 140 is an application-level process that communicates with the message router 150 on behalf of other processes, such as the system manager 120 , in order to send and receive messages among the embedded client systems 200 . In one embodiment, the queue manager 140 is implemented as a C++ object. The queue manager 140 also manages incoming and outgoing queues on behalf of the other processes in the system server 100 .
The queue manager 140 handles two types of queues, persistent queues and volatile queues. Messages, whose message type indicates persistent storage, are stored such that the message will not be lost during power outages and lost network connections. A persistent queue is stored in persistent flash memory or in a location on the hard disk of the network device. Other messages, not intended for persistent storage, are stored to volatile queues and might be lost during power outage and lost network connections.
The data store 130 is a database that stores the attributes of the user profiles, group profiles, content and promotions along with the activation criteria. In addition, the data store 130 stores messages intended for network devices that are unavailable during the initial delivery attempt. The data store provides persistence to the data stored such that the content, profiles, and messages will not be lost during a power outage. In one embodiment, the data store 130 is a Microsoft® SQL version 7 database. Since the data store stores content, it is also known as a content store.
The bulk data transfer manager 160 is an application-level process that is responsible for the transfer of bulk data to targeted network devices. Bulk data include large stream-oriented data, such as a promotions, files, or registry sub-key hives. The bulk data transfer manager 160 does not transmit data over the messaging protocol. Instead, it transmits serialized data over a network transport protocol, such as TCP/IP. The bulk data transfer manager 160 has access to the data store 130 for transmitting content and promotions.
The XML File Processor 170 is an application-level process that is responsible for parsing out the user attributes from the raw user activity and event logs and updating the appropriate user profiles. In one embodiment, the logs are stored as XML files in the data store 130 .
In more detail of the embedded client system 200 , the system agent 220 is an application-level process that communicates with the system manager 120 handling various request messages and registration. In handling the various request messages, the system agent communicates with the other embedded client system components in order to effect a proper response or behavior. In one embodiment, the system agent 220 is implemented as a C++ object.
As in the system server, the queue manager 240 is an application-level process that communicates with the message router 150 on behalf of other processes, such as the system agent 220 , in order to send and receive messages to the system server 100 and other network devices. In one embodiment, the queue manager 240 is implemented as a C++ object. The queue manager 240 also manages incoming and outgoing queues on behalf of the other processes in the embedded client system 200 .
The queue manager 240 handles two types of queues, persistent queues and volatile queues. Messages, whose message type indicates persistent storage, are stored such that the message will not be lost during power outages and lost network connections. A persistent queue is stored in persistent flash memory or in a location on the hard disk of the network device. Other messages, not intended for persistent storage, are stored to volatile queues and might be lost during power outage and lost network connections.
The bulk data transfer agent 260 is an application-level process that handles requests from the system agent 220 to either download content and promotions or upload user activity and event logs. The bulk data transfer agent 260 communicates with the bulk data transfer manager 160 of the system server 100 over a network transport protocol, such as TCP/IP. The bulk data transfer agent 260 notifies the system agent 220 upon completion or failure of the data transfer. In one embodiment, the system agent 220 is implemented as a C++ object.
The promotion notification agent 230 is an application-level process that triggers and handles the display of promotions. The promotion notification agent 230 overlays the promotion or promotions onto the video signal that gets displayed on a monitor connected to a set-top box or to a web phone display. The promotion notification agent 230 coordinates the activation of promotions. A promotion notification agent 230 will display the promotion in response to an event, invocation by the system manager 120 , or scheduling information provided with the promotion itself.
The web browser 210 is an application-level process that displays web pages from web host servers such as the management console 110 of the system server 100 enabling registration of user attributes.
The logging agent 250 is an application-level component that monitors and logs a variety of user activities and events. In one embodiment, the logging agent 250 stores the log files in XML format. User activities and events that are tracked by the logging agent 250 are channel events, promotion events, power events, peripheral events, and application events.
Channel events occur whenever the network device stays tuned to a channel for a configurable amount of time. Promotion events occur in response to consumer actions taken with respect to promotions displayed on the video display. For example, a promotion event is recorded when the consumer clicks or selects the promotion icon to navigate to the web server hosting the promotion.
The interaction of the server system 100 and the embedded client system 200 provides a system for targeting and scheduling deployment of promotional content to consumers of a targeted market segment, for managing the activation of the promotional content, and for tracking consumer response to the promotion.
Application-level processes, such as the system manager 120 of the server system and the system agent 220 of the network device, communicate over the data network through messages.
Messages transfer requests for action, responses to requests, and small data transfers. Messages are transported in the payload of a network transport protocol, such as TCP/IP. Messages are sent to destinations using a globally unique identifier, GUID, in order to identify the destination network device or application. This messaging protocol allows application-level processes to transmit data without knowing about the network transport interface, the device's network address, or whether the device is active on the data network.
The interaction of the message router 150 with the queue managers of the source and destination processes implements the messaging protocol. Any queue manager whether it is executing on the system server 100 or the embedded client system 200 communicates with the message router 150 in the same manner.
FIG. 2B illustrates the interaction between a queue manager and the message router 150 according to the invention. For example, when the system manager 120 needs to transmit a message to a system agent 220 , the system manager 120 , in step 1000 , sends the message to the queue manager 140 indicating the message type, a globally unique identifier (i.e., GUID) of the destination device, and the message data. The details on how a network device obtains a GUID is described later with reference to FIG. 3 .
In step 1002 , the queue manager 140 stores the message in a queue for the system manager 120 and then attempts to establish a connection with the message router 150 .
In brief overview, there are three steps in order for the queue manager 140 to establish a connection to the message router 150 . In step 1004 , the queue manager 140 determines the IP address of the message router 150 . In step 1006 , the queue manager 140 creates and opens a socket pair connection to the message router 150 for transmitting serialized data. In step 1008 , the queue manager 140 sends a message to the message router 150 indicating that the queue manager 140 is alive and connected and ready to transmit serialized data.
In more detail of step 1004 , the queue manager 140 has one of its properties being the location or name of the message router 150 . Using DNS, or IP host name services, the queue manager 140 determines the IP address of the message router 150 . If the queue manager 140 cannot resolve the IP address of the message router 150 , the queue manager 140 resorts to a broadcasting scheme. The queue manager 140 broadcasts a locator message on its subnet attempting to locate the message router 150 . If there is a message router 150 on that subnet, the message router 150 responds back with its IP address. This address is cached by the queue manager 140 for future connections.
In step 1006 , the queue manager 140 , knowing the IP address of the message router 150 , creates and opens a socket pair on predetermined, known ports for transmitting serialized data.
In step 1008 , once the socket pair is opened, the queue manager 140 sends a message notifying the message router 150 that the queue manager 140 is alive and connected and has socket pairs on which to read or write serialized data.
In step 1010 , the queue manager 140 writes the message for delivery to the message router 150 through the established TCP/IP socket connection FIG. 2C illustrates the process of delivering the message once received by the message router 150 .
Upon completion of the writing of the message, the message router 150 extracts the message type and the destination GUID from the message in step 1012 .
In step 1014 , the message router 150 resolves the destination GUID by looking-up the IP address associated with the GUID in the data store 130 .
In step 1016 , the message is encapsulated in an IP packet, with the appropriate destination IP address. In one embodiment, the IP address of the network device becomes known to the system server 100 during initial registration of the network device and is stored as an attribute of the user profile.
In step 1018 , the message router 150 determines the type of the message. The message type indicates the quality of service that the message router 150 provides for delivery of the message.
If the message type is a standard datagram, the message router 150 simply transmits the message in step 1022 . The message router 150 will not keep track of whether the message was actually received.
If the message type indicates guaranteed delivery, the message router 150 will transmit the message and wait for an acknowledgment from the destination device in step 1024 .
If no acknowledgment is received after several attempts, the destination is deemed unavailable and the message is stored in the data store 130 for later retransmission when the destination is active on the data network in step 1028 . Specifically, in step 1029 , the message router waits for the network device 80 to become active in order to deliver the message. In one embodiment, the message router 150 is notified that the network device is active by receiving a message from the network device 80 indicating its active status. In an alternative embodiment, the message router is notified of the active status of a previously unavailable network device by the system manager 120 which monitors the status of the network devices 80 . When the network device becomes active, the message router proceeds back to step 1018 to begin the process of delivery again.
If the acknowledgment is received, then, in step 1030 , the delivery is complete and the message is removed from the data store 130 if the network device was previously unavailable.
The interaction of the message router 150 and the queue manager 140 for delivering messages occurs whenever a message is sent or received using the messaging protocol.
In order for the server system 100 to target content and promotions to a particular market segment, the server system 100 references its stored user profiles, each user profile being a collection of user and device attributes associated with a network device. All network devices whose user profiles match the attributes of the group profile, targeted by a system administrator, are scheduled for content deployment.
However, when a network device is connected to the network infrastructure for the first time, the system server does not have a user profile for the network device. The present invention provides an automated system and method for initially registering and generating a user profile for an network device.
FIG. 3 is a state line diagram showing the interaction of the server system 100 and the embedded client system 200 for generating an initial user profile for a network device.
In step 1 , the system agent 220 of the network device generates and transmits a registration request message containing a number of device attributes to the system manager 120 .
The device attributes describes the network device and is configured during the manufacturing process of the device itself. For example, the network device may be configured with a model number attribute for a particular group of network devices, such as intelligent set-top boxes, version 1.0.
In step 2 , the system manager 120 receives the registration request message and, in response, retrieves a globally unique identifier, GUID, from an available pool of GUIDs stored in the data store 130 .
In step 3 , the system manager 120 generates and transmits a registration response message containing the assigned GUID to the system agent 220 of the registering device.
The assigned GUID is used by the network device to identify itself in messages transmitted to the system server 100 and to other network devices. The assigned GUID is also used by the system server 100 to associate the network device with a user profile within the data store 130 .
In step 4 , the system agent 220 launches a web browser 210 . The web browser 210 transmits an HTTP request to the URL (Uniform Resource Locator) of the management console 110 for a registration web page. The assigned GUID is included in the URL string in order to identify the registering network device.
In step 5 , the management console 110 receives the HTTP request. In response, the management console 110 makes a call via the COM interface of the system manager 120 to retrieve the device and user attributes, if any, associated with the GUID of the registering network device. The management console 110 generates the registration web page customized for the registering network device. The web page is transmitted via HTTP to the web browser 210 .
In step 6 , the web browser 210 displays the registration web page wherein the user submits information which will be used to generate a user profile of user attributes associated with the network device. Such information includes, but is not limited to, name and address information, channels frequently watched, requests for installation of optional value-add services and applications, and various demographic and personal information.
Upon submitting the registration data, the web browser 210 transmits the user attributes, represented as HTML data via HTTP, to the management console 110 .
In step 7 , the management console 110 interprets the HTML data stream and makes calls via the COM interface of the system manager 120 to update the user profiles in the data store 130 with the provided user attributes.
In step 0 . 8 , the system manager 120 updates the user profile of the registering network device with the user attributes on the data store 130 . After updating the user profile, the system manager 120 associates the user profile with group profiles whose attributes match user attributes of the user profile.
For example, the user profile will be added to the group profile for network devices with the same model number attribute. The user profile is added to any number of group profiles that target particular attributes of the registered user or network device. These group profiles are used by the system manager 120 for targeting consumers of particular market segments for various e-commerce promotions or application services.
Once the network device is registered and is associated with a user profile, the device is capable of being targeted for deployment of content or promotions.
FIG. 4A is a state line diagram showing the interaction of the server system and the embedded client system for deployment of content and promotions to a network device. Deployment includes, but is not limited to, downloading and installing.
Before content can be deployed to a targeted device, the content must be stored in the data store 130 along with a group profile and an activation schedule. The group profile indicates the attributes of network devices to target. The activation schedule indicates when to activate the content or promotions. Activation can be event driven, scheduled from the system server 100 , or initiated by the system manager 120 .
In step 1 , a system administrator with access to the management console 110 populates a server-based web page indicating the content to deploy as well as the criteria with which to define the group profile. Additionally, the system administrator indicates when to activate the content. Upon submitting the data, the management console 110 makes a call to the COM interface of the system manager 120 to generate a group profile in the data store 130 with user profiles whose attributes match the criteria defined by the system administrator.
In step 2 , the system manager 120 updates the data store 130 creating the group profile and populating the group profile with user profiles with matching attributes.
In step 3 , the management console 110 make a call through the COM interface of the system manager 120 to download the content or promotion to the data store 130 .
In step 4 , the system manager 120 writes the content to the data store 130 .
The system manager 120 is configured to schedule deployment of content during off-peak hours when bandwidth utilization is typically at a minimum. For example, during the hours of 3:00 AM and 5:00 AM, more bandwidth is available for efficient deployment of content and promotions. Alternatively, the system manager 120 monitors network utilization and is configured to schedule deployment of content when the detected bandwidth utilization falls below a predetermined level.
In step 5 , the system manager 120 sends a download and install request message to each of the system agents 220 of the network devices whose user attributes match the attributes of the group profile. The download and install message informs the system agent 220 to download install the content or promotion referenced by a GUID.
Alternatively, the system manager 120 sends a download, install, and start request message which indicates, in addition, when or under what event conditions the content should be activated (i.e. promotion displayed or an application launched).
In step 6 , the system agent 220 makes a C++ object method call to the bulk data transfer agent 260 to download the content having the provided GUID.
In step 7 , the bulk data transfer agent 260 sets up a TCP/IP socket connection to the bulk data transfer manager 160 of the server system to initiate the delivery of the application.
In step 8 , the bulk data transfer manager 160 delivers the requested content to the bulk data transfer agent 260 through the TCP/IP socket connection. In cases where the connection is broken, the bulk data transfer agent 260 and the bulk data transfer manager 160 can detect that a connection was broken and will continue the download the content from the point in the transfer where the break occurred.
In step 9 , the bulk data transfer agent 260 notifies the system agent 220 the result of the data transfer via an C++ object method call.
In step 10 , the system agent 220 sends a message to the system manager 120 indicating the result of the data transfer.
After the content is installed on the targeted network device, the present invention provides a system and method for activating that content. Activation allows the user to interact with the installed content, such as playing a game or initiating an e-commerce transaction.
There are two types of activation that the present invention implements scheduled activation and event driven activation. Scheduled activation allows the system administrator to specify when to activate the content, whereas event driven activation allows the system administrator to specify an event which triggers the activation of the content.
Scheduled activation is implemented in two ways, predetermined scheduling and activation by the system server.
FIG. 4B illustrates the steps associated with content activation via predetermined scheduling. Predetermined scheduling based upon date and time provides the most autonomy to the network device. After the content is deployed, the network device simply waits for the specified date and time to arrive, at which time it displays the content.
In step 1110 , when the group profiles are configured and the content is downloaded to the data store 130 , the system administrator also specifies the date and time to activate the content. Where the content is a promotion, a duration period is specified along with the activation date and time.
In step 1112 , the system manager 120 sends the download, install, and start request message to the system agent 220 of a targeted network device. In addition to requesting the system agent 220 to install content, the message indicates the date and time to activate the installed content.
If the content is a not a promotion, the system agent 220 waits for the specified activation date and time in step 1116 .
In step 1118 , the content is activated by the system agent 220 at the specified date and time.
If the content is a promotion, the system agent 220 transfers the predetermined date, time, and duration to the promotion notification agent 230 in step 1120 .
In step 1122 , the promotion notification agent 230 waits for the specified activation date and time.
In step 1124 , the promotion is activated by the promotion notification agent 230 at the specified activation date and time.
If the promotion is a icon or graphic linked to a URL of a host web server, the promotion notification agent 230 overlays the promotion on a portion of the video display built-in or attached to the network device. If the promotion is audio clip or data stream, the audio is played through a speaker built-in or attached to the network device. If the promotion is a video clip or data stream, the video overlays a portion of the video display built-in or attached to the network device.
FIG. 4C illustrates the steps associated with server activation of content. Server activation of content allows control to reside at the server system 100 , therefore, maximizing the control by the institution operating the server system 100 .
As described previously, the content is installed on the network device in step 1210 with no activation information.
In step 1212 , the system agent 220 waits for a start message from the system server 100 .
In step 1214 , upon request of the system administrator, the system manager 120 sends a start message to the system agent 220 specifying the installed content to activate.
If the installed content is not a promotion, the system agent activates the content in response to receiving the message in step 1218 . This may include, but not limited to, launching an application installed within the network device.
If the installed content is a promotion, the system agent 220 notifies the promotion notification agent 230 via a C++ object method call to activate the specified promotion in step 1220 .
In step 1222 , the promotion is activated by the promotion notification agent 230 .
Event driven activation is particularly suited for coordinating the activation of content with a particular event or a particular moment in a corresponding analog and/or digital video stream.
Event activation has advantages associated with high scalability. The content can be loaded in the days or weeks preceding the general time period when it is to be displayed.
In one embodiment, events that trigger content activation are channel events, power events, and peripheral events. A power event is an event relating to the power supply, such as the network device being powered on or off. A peripheral event is an event relating to peripheral devices being connected or disconnected from the network device, such as a joy stick or other gaming console. A channel event is an event relating to the channel being watched by the user.
FIG. 4D illustrates the steps associated with event driven activation according to the invention.
In step 1310 , when the group profiles are configured and the content is downloaded to the data store 130 , the system administrator also specifies an event map. An event map associates events to content indicating when to activate the content. Where the content is a promotion, a duration period is specified as well.
In step 1312 , the system manager 120 sends the event map in a message, such as a download, install, and start message, to the system agent 220 of a targeted network device.
If the content is not a promotion, the system agent 220 waits for the specified event or events that trigger the activation of the content in step 1316 .
In step 1318 , the system agent 220 activates the content when the specified event or events occur.
Conversely, if the content is a promotion, the system agent 220 transfers the event map to the promotion notification agent 230 in step 1320 .
In step 1322 , the promotion notification agent 230 waits for the specified event or events to occur.
In step 1324 , the promotion notification agent 230 activates the promotions associated with the event or events that occurred.
An example of event driven activation is where the event map provides for the activation of promotions involving sporting goods when the potential consumer has been watching a particular sports channel for a period of time. The watching of the sports channel for a period of time triggers a channel event. The channel event triggers the activation of the promotion or promotions.
The present invention provides an additional implementation of event driven activation involving technology from ATVEF (Advanced Television Enhancement Forum). ATVEF provides a standard for embedding HTML tags within a video signal.
The promotion content agent 230 monitors the video signal for the embedded triggers, such as the HTML tag. The capture of this embedded trigger causes the activation of one or more promotions in real-time coinciding with the video signal.
Such a system has advantages in that very little video signal editing is required. Only a small trigger has to be embedded in the video signal, requiring little analog video editing capabilities at the data center.
The content, is simultaneously activated on all of the network devices allowing high levels of synchronization to the video signal. For example, the promotion can be synchronized to occur during a television commercial.
The provider of the commercial simply embeds an initialization or start HTML tag within its video signal. In response to the promotion notification agent 230 capturing the HTML tag, the promotion notification agent 230 activates the appropriate promotion or promotions specified in the event map for that HTML tag.
FIG. 4E shows one embodiment of this system on a conventional set-top box 80 for an analog or an analog/digital video display device such as a television 300 . Specifically, the data and audio/video stream is received by the set-top box 80 . This data audio/video stream is received from the head end 50 via the hub 60 .
The promotion content agent 230 of the embedded client system 200 monitors the video stream for the embedded trigger signal. When the trigger signal is detected, the promotion content agent 230 inserts the associated graphical promotion content indicated in the event map into the analog or digital video stream to the display 310 of the television 300 . As a result, the promotion 320 appears on the display screen 310 , overlaying the video.
User selection of this promotion through a selecting device, such as a remote control device, sends a URL to the web browser 210 bringing the browser window to the forefront of the display 310 of the television 300 . In this way, user selection of the promotion allows the user to receive and view data from the URL enabling e-commerce transactions.
Therefore, the event-driven activation, as well as the other scheduling options, presents promotions in an appropriate context to further increase the likelihood of consumer e-commerce transactions.
In addition to the initial registration process, the present invention includes a system and method for updating user profiles through uploading distributed user activity and event logs to the system server 100 , parsing out the user and device attributes from the logs, and updating the user profiles in the data store 130 .
The logs provide useful information, because the logs track a variety of information which the system can use in order to more accurately target users for content and promotional deployment. In one embodiment, the logs track channel events and e-commerce transactions initiated through the display of promotions. In another embodiment, the logs track peripheral events, such as the addition of a joystick and console for gaming purposes, power events, application events, and promotion events. Continuous updating of user profiles through this system and method improves the targeting of consumers for content deployment, and in particular, for promotional content deployment.
In brief overview, the network device includes a logging component 250 that monitors and logs user activity and events in an generic file format. For example, the logging component 250 monitors user activity at a user interface device such as the television remote channel control. In one embodiment, the generic file format is Extensible Markup Language (XML). The format of the log files, using XML, correspond to the structure of the user profiles in the data store 130 . This allows for processing of the logs in an automated fashion.
In addition, the user activity and event logs include a description of the structure of the document itself. Using XML, the description of the structure of the document is the Document Type Definition (DTD). Providing a description of the document structure within the logs themselves, allows for the server system 100 to process logs with different document structures. This avoids the necessity of having to update the server system 100 every time a new document structure is used within the logs.
FIG. 5A is an example of a DTD for an event log where each event that occurs is recorded with the GUID of the device, the time of the event, the event type, and a description of the event.
FIG. 5B is an example of an event log written in XML using the DTD of FIG. 5 A. The event log contains two events, stored in the structure described by the DTD. FIG. 5B demonstrates how a channel event and an application event are described within this log.
The uploading and parsing of these user activity and event logs will provide additional user attributes for targeting consumers including information regarding responses to prior promotions. If the logs indicate that a user is interested in a particular type of promotion, the system server modifies the user attributes of his user profile such that they match the attributes of a group profile associated with that type of promotion.
FIG. 6 is a state line diagram showing the interaction of the server system 100 and the embedded client system 200 for updating user profiles through the upload and parsing of user activity and event logs.
In step 1 , the system manager 120 sends a message to the system agent 220 to upload its activity logs to the server system.
In step 2 , the system agent 220 makes a C++ object method call to the bulk data transfer agent 260 to upload the user activity and event logs.
In step 3 , the bulk data transfer agent 260 sets up a TCP/IP socket connection to the bulk data transfer manager 160 of the server system to initiate the delivery of the logs.
In step 4 , the bulk data transfer agent 260 delivers the logs to the bulk data transfer manager 160 through the TCP/IP socket connection where they are stored in the data store 130 .
In cases where the connection is broken, the bulk data transfer agent 260 and the bulk data transfer manager 260 can detect that a connection was broken and will continue the download the content from the point in the transfer where the break occurred.
In step 5 , the bulk data transfer agent 260 notifies the system agent 220 the result of the data transfer via a C++ object method call.
In step 6 , the system agent 220 sends a message to the system manager 120 indicating the result of the data transfer.
In step 7 , the system manager 120 makes a call to the XML file processor 170 to update the user profiles from the user activity and event logs.
In step 8 , an XML file processor 170 at the server system parses the logs stored on the database and updates the user attributes of the user profile of the network device. This system and method for scheduling remote uploads of the user activity and event logs provides improves the efficiency for targeting consumers for content and promotion.
There are situations where a user will change the hardware configuration of a network device in order to expand its capabilities. In that situation, the present invention provides a system and method by which the network device notifies the server system 100 of a change to its hardware configuration and, in return, receives the appropriate device drivers to support the new hardware configuration.
FIG. 7 shows the dynamic installation of device drivers on the network device according to the present invention.
Specifically, the dynamic driver installation process is triggered when the user installs a peripheral device on a network device for which the network device requires a driver. In the typical example, the process occurs when the user plugs in a peripheral device such as a joy stick into a port such as a serial port or USB (universal serial bus) port.
In step 1002 , the system agent 220 intercepts the plug and play string from the peripheral device when it is attached to the USB port.
In step 1004 the system agent 220 then sends this plug and play string to the system manager 120 via the message router 150 and the queue managers along the path between the system agent 220 and the system manager 120 .
In step 1006 , the system manager 220 then searches for a matching driver in its data store 130 . Specifically, it compares the plug and play string received from the network device to plug and play strings of supported operating systems and supporting peripheral devices for which drivers are available.
In step 1008 , assuming the valid device driver has been located, the system manager 120 sends a message to the system agent 220 to download the driver providing its location in the data store 130 .
In step 1010 , the system agent requests the bulk data transfer agent 260 on the network device to download the driver. The bulk data transfer agent 260 then contacts the bulk data transfer manager 160 and downloads and stores the device driver on the network device. In parallel, the system manager 120 instructs the system agent 220 on how to install the device driver on the network device.
In step 1012 , in the typical implementation, the device driver is dynamically loaded onto the network device.
In step 1014 , when the driver has been successfully installed, the system agent 220 notifies the system manager 120 . The system manager, in turn, updates the status of the network device in the system manager's data store 130 .
FIG. 8 illustrates the mirror process in which the peripheral device driver is uninstalled.
In step 1016 , the system agent 220 is notified when the peripheral is disconnected by the user from the network device.
In step 1018 , the system agent 220 then requests an uninstall program from the system manager 120 .
In step 1020 , typically, the bulk data transfer agent 260 obtains the uninstalled program from the bulk data transfer manager 160 .
In step 1022 , the driver is then uninstalled.
In step 1024 , upon the successful uninstall, the system agent 220 notifies the system manager 120 that the driver has been installed and the system manager 120 updates the network device's status.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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The present disclosed system is directed toward a communication and management system that dynamically targets network devices for content deployment, such as application programs, device drivers, configuration files, and registry subhives. Moreover, the present system targets users of network devices for promotions, such as advertisements offered by Internet e-commerce sites. Promotions are generally icons or graphic images with links to host web servers overlaying a video display, but also includes audio and video clips or data streams. Network devices and their users are targeted through user profiles. User profiles are created when network devices register with the system server and are continually updated with information provided by user activity and event logs that are periodically uploaded from each device, a scalable messaging system provides for data transmission between the system server and among the network devices such that it is neutral as to the specific hardware platforms on which it is implemented.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to control systems for remotely controlled model airplanes and, more particularly, to magnetically operated centrally biased control surfaces for a model airplane.
[0003] 2. Description of Related Prior Art
[0004] Remotely controlled, and formerly referred to as radio controlled, model airplanes have been built and flown as a hobby since the 1940s when vacuum tube operated transmitters and receivers became available for use in model airplanes. With advances in the transmitter/receiver art, there have been significant size and weight reductions in the related equipment and there have been significant improvements in reducing the electrical power requirements. With such reductions in size and weight, smaller and lighter model airplanes became possible to be remotely controlled.
[0005] Initially, the control system actuated by a signal from the receiver was a rubber band driven escapement that provided left or right rudder deflection for directional control. Generally, such escapements lacked sufficient power to deflect the elevator to obtain a change in pitch or to deflect the ailerons to obtain a left or right rolling moment about the longitudinal axis. Moreover, control of the engine speed and operation was primarily limited to shutting down the engine, which engine was usually a single cylinder internal combustion engine. As technology advanced, several servo mechanisms were developed which had significant power to operate the various control surfaces and to provide a throttling capability for the engine. During the last ten years or so, the size of these servos has been significantly reduced. They also became capable of full proportional control to accurately deflect the respective control surface(s).
[0006] Through careful aerodynamic design of a model airplane, it is possible to control not only the direction of flight but also the pitch attitude of a model airplane using only deflection of the rudder. A skilled pilot can even do basic aerobatic maneuvers using only selected timed rudder deflection. For small sized lightweight model airplanes, a magnetic actuator for the rudder was available a number of years ago. This actuator included a coil to drive a linkage connected to the rudder of the model airplane. The signal transmitted by the transmitter and received by the receiver either energized the coil or de-energized the coil. The rudder was biased in one direction during the absence of a signal and upon transmission of a control signal, the coil was energized to cause deflection of the rudder in the other direction. By regulating the relative on/off periods of energizing the coil, directional control of the airplane could be maintained but a great deal of skill by the ground based pilot was required. Because of the low power output of the coil, the linkage connected to the rudder had to be very carefully adjusted, be essentially slop free and minimal friction was required.
[0007] With the advent of micro sized receivers, electric motors and small powerful batteries, small and light weight model airplanes can now be remotely controlled. As small and light weight model airplanes require relatively small forces to actuate control surfaces for controlling movement in the pitch, yaw and longitudinal axis, new and innovative low power servo mechanisms can be used for these purposes.
SUMMARY OF THE INVENTION
[0008] A conventionally configured model airplane that has a fuselage supporting a wing for generating lift, a fixed horizontal stabilizer for providing stability in the pitch axis and a vertical stabilizer for providing stability in the yaw axis includes a pivotally mounted rudder biased to the center position. A motor driven propeller for providing thrust may be included. A ground based transmitter includes a control to regulate left and right deflection of the rudder and may include a further control for the airplane motor to regulate the thrust. By such deflection of the rudder, the direction of travel of the model airplane can be controlled. A coil fixedly attached to the vertical stabilizer adjacent the hinge line with the rudder is energized to provide a magnetic field having a first or second polarity. A magnet attached to the rudder proximate the coil is responsive to each magnetic field generated and as a result of such response is urged to pivot to the left or the right. In response to the movement of the magnet, the rudder will be deflected left or right and the model airplane will change direction accordingly. On cessation of a signal actuating the coil, the hinges interconnecting the rudder with the vertical stabilizer bias the rudder to the center position. Thereby, the control signals generated by the transmitter and received by the receiver to actuate the coil provide left or right deflection of the rudder and a mechanical hinge automatically returns the rudder to the central position.
[0009] If the transmitter and receiver are appropriately configured, 2-axis control of the model airplane is possible. To implement such 2-axis control, the horizontal stabilizer includes an elevator actuated by the above described coil and magnet. For a model airplane having a V-tail, each of the control surfaces is actuated by such a coil and magnet to provide control in the yaw axis and the pitch axis. A flying wing may include elevons each of which is actuated by the same type of coil and magnet to provide control about the pitch axis and about the longitudinal axis.
[0010] It is therefore a primary object of the present invention to provide a lightweight control system for controlling the flight of a remotely controlled model airplane.
[0011] Another object of the present invention is to provide a selectively actuated coil for deflecting a control surface of a model airplane in one direction or the other.
[0012] Still another object of the present invention is to provide a rudder for a model airplane that is biased to the central position and deflectable left or right in response to a created magnetic field.
[0013] Yet another object of this invention is to provide a magnet mounted on a control surface of a model airplane responsive to a selectively actuated coil for controlling the direction of flight of the model airplane.
[0014] A further object of the present invention is to provide flexible hinges for a control surface of a model airplane to bias the control surface to the central position and yet accommodate movement of the control surface about the hinge line in response to a magnetic field acting upon a magnet secured to the control surface.
[0015] A still further object of the present invention is to provide a low cost operating system for selectively deflecting one or more control surfaces of a model airplane.
[0016] A yet further object of the present invention is to provide a magnetically actuated rudder for a model airplane.
[0017] A yet further object of the present invention is to provide a magnetically actuated elevator for a model airplane.
[0018] A yet further object of the present invention is to provide magnetically actuated control surfaces of a V-tail model airplane.
[0019] A yet further object of the present invention is to provide magnetically actuated elevons of a flying wing model airplane.
[0020] A yet further object of the present invention is to provide a method for magnetically controlling the deflection of a control surface of a model airplane.
[0021] These and other objects of the present invention will become apparent to those skilled in the art and the description there proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:
[0023] FIG. 1 is an isometric view of a remotely controlled model airplane incorporating the present invention;
[0024] FIG. 1A is a representative view of a transmitter for transmitting control signals to the model airplane shown in FIG. 1 ;
[0025] FIG. 2 is a side view of the model airplane;
[0026] FIG. 3 is a top view of a coil mounted on the vertical stabilizer and a magnet mounted on the rudder of a model airplane and taken along lines 3 - 3 , as shown in FIG. 2 ;
[0027] FIG. 3A is a further detailed view of the coil and magnet;
[0028] FIG. 4 is a partial side view of the interconnection between the vertical stabilizer and the rudder;
[0029] FIG. 5 is a cross sectional view taken along lines 5 - 5 , as shown in FIG. 4 ;
[0030] FIG. 6 illustrates a flying wing having elevons as control surfaces;
[0031] FIG. 7 is a detail view of an elevon, illustrating a coil and a magnet for actuating the elevon;
[0032] FIG. 8 is a cross section taken along lines 8 - 8 , as shown in FIG. 7 ;
[0033] FIG. 9 illustrates a conventional horizontal stabilizer with elevators and a vertical stabilizer with rudder forming the rear empennage of a model airplane;
[0034] FIG. 10 illustrates a V-tail of a model airplane having control surfaces; and
[0035] FIG. 11 illustrates a 2-axis transmitter for use with the model airplanes, as shown in FIGS. 6, 9 and 10 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] Referring to FIG. 1 , there is shown a model airplane 10 . The airplane includes a fuselage 12 supporting a wing 14 for generating lift upon forward motion of the plane. A horizontal stabilizer 16 provides stability in the pitch axis and is generally in alignment with longitudinal axis 18 . However, for stability purposes, the horizontal stabilizer may have a small negative angle of attack. A vertical stabilizer 20 provides stability about the yaw axis of the model airplane. A propeller 22 is turned by a motor (see FIG. 2 ) mounted within fuselage 12 and provides thrust for forward motion of the model airplane. A rudder 24 is hingedly attached to vertical stabilizer 20 and upon movement left or right, as depicted by dashed lines 26 , 28 , the direction of flight of the airplane will change to the left or to the right, respectively.
[0037] Model airplane 10 is remotely controlled, sometimes referred to as radio controlled. Referring jointly to FIGS. 1, 1A and 2 , the remote control apparatus will be described. A transmitter 30 includes an antenna for radiating the transmitted signal. The transmitted signal is sensed by antenna 34 electrically connected to receiver 36 mounted within fuselage 12 . The transmitter includes several controls. A button 38 , or the like, on transmitter 30 provides an on/off function for motor 40 located in the nose 10 of model airplane 10 . Typically, a gear box 42 interconnects the armature of motor 40 with propeller 22 . Also typically, electrical power to the motor is provided by battery 44 through electrical conductors 46 connected with the circuitry in receiver 36 and through electrical conductor 48 providing power to motor 40 upon actuation of button 38 in the transmitter. Thereby, transmitter 30 controls the thrust produced by propeller 22 .
[0038] When button 50 on transmitter 30 is depressed, a signal for a left turn is generated and transmitted. This signal is sensed by receiver 36 through antenna 34 and suitably demodulated by demodulator 52 , which demodulator may be a part of the circuitry of the receiver. The demodulator produces a control signal via electrical conductors 54 , 56 to energize coil 58 . Upon applying electrical power to the coil, it will produce a magnetic field of a first polarity. Control of the magnetic polarity is a function of which of conductors 54 , 56 conveys a greater positive voltage to the coil. Upon depressing button 60 on transmitter 30 , a further signal is transmitted via antenna 32 and sensed by receiver 36 through antenna 34 . Demodulator 52 demodulates this signal and produces a further control signal on electrical conductors 54 , 56 . This further control signal is of the reverse polarity of the control signal on conductors 54 , 56 when button 50 is depressed. Thus, the magnetic field produced by coil 58 is now reversed in polarity. As depicted by arrow 62 on transmitter 30 , button 50 corresponds. with a left turn and button 60 corresponds with a right turn.
[0039] Additional indicators 64 , 66 may be employed in the transmitter to indicate the voltage state of the circuitry driving the transmitter, the state of charge in the event battery 44 is charged by the transmitter upon moving the battery from the model airplane to a compartment within the transmitter. Other indicia for various purposes may also be incorporated.
[0040] Referring jointly to FIGS. 2, 3 , 3 A, 4 and 5 , details attendant the attachment of rudder 24 to vertical stabilizer 20 and operation of the rudder will be described. Coil 58 is mounted in vertical stabilizer 20 close to hinge line 70 , representatively shown as the trailing edge of the vertical stabilizer. Electrical conductors 54 , 56 provide power to the coil and produce the above described magnetic field having a first or a second polarity. Rudder 24 is attached to the vertical stabilizer by a pair of segments of rubber bands 72 , 74 . Typically, the end of each rubber band is inserted and glued within a slot at hinge line 70 of the vertical stabilizer 20 and similarly lodged and glued within corresponding slots in rudder 24 . As illustrated, a space exists between the rudder and the vertical stabilizer. The purpose of this space is to permit the rudder to deflect left and right relative to the vertical stabilizer without binding or otherwise contacting the hinge line or other part of the vertical stabilizer during the normal extension of rudder deflection left and right. A magnet 76 is secured to the leading edge of rudder 24 by a dab of glue, a strap 78 , as shown, or other device.
[0041] Upon energizing coil 58 by pushing button 50 on transmitter 30 , the coil will create a magnetic field to attract the left side of magnet 76 , hereinafter referred to as pole 80 . In response to such magnetic attraction, pole 80 will be drawn toward and move toward coil 58 . The resulting movement of the magnet will cause the rudder to deflect to the left, as shown in FIG. 3A and represented by dashed line 82 . With the rudder moved to the left, model airplane 10 will go into a left turn. Once button 50 is released, no further power is applied to coil 58 . Without such power, magnet 76 is no longer attracted to the coil. The resiliency of rubber bands 72 , 74 will therefore urge the rudder to its central position, as depicted in FIG. 3, 3A which essentially aligns the rudder with the vertical stabilizer. With such alignment, model airplane 10 will travel essentially straight ahead. Upon depressing button 60 of transmitter 30 , a further control signal will be generated and conveyed to coil 58 through electrical conductors 54 , 56 . This further control signal is of opposite polarity, as discussed above, and the magnetic field produced by the coil is of opposite polarity also. As a result, pole 84 of magnet 76 will be attracted to the coil. Such attraction will result in commensurate movement of the magnet and rudder 24 coupled with the magnet. The extent of movement is represented by dashed line 86 .
[0042] With the rudder in this position, model airplane 10 will turn to the right. On release of button 60 , the magnetic field generated by coil 58 will cease and neither pole 80 or 84 of magnet 76 will be attracted to the coil. Hence, rudder 24 will once again will become essentially aligned with vertical stabilizer 20 in response to urging by rubber bands 72 , 74 . As a result, the model airplane will once again fly straight ahead.
[0043] As illustrated in FIG. 2 , the model airplane may include an undercarriage 90 to permit taxiing on a surface and to take off along a simulated runway. Similarly, the undercarriage will permit landing on a smooth surface in the manner of a conventional airplane. During such taxiing and take off, buttons 50 and 60 on transmitter 30 may be actuated to control the direction of movement of the model airplane during both taxiing and take off.
[0044] Referring to FIG. 6 , there is illustrated a representative flying wing 100 . A model airplane of this type generally includes a center section 102 , sometimes referred to as a fuselage, for housing a remote control receiver and batteries. Although not shown, a motor driving a propeller may be mounted in nose 104 of the center section to provide thrust. Alternatively, such a motor and propeller may be mounted at tail 106 . Usually, one or more rudders 108 are provided for directional stability. Control of flying wing 100 about the pitch axis and the longitudinal axis is obtained by operation of elevons 110 , 112 . When these elevons operate in concert, either up or down, the pitch attitude of the flying wing is changed. When these elevons operate in the opposite directions, that is, one elevon is deflected upwardly and the other elevon is deflected downwardly, forces are generated to cause the flying wing to rotate about its longitudinal axis. Such rotation results in the lift produced by the flying wing to be toward the inside of the bank and result in turning of the flying wing.
[0045] The structure and operation of the elevons will be described with specific reference to FIGS. 6, 7 and 8 . Elevon 12 is pivotally attached to wing 114 by two or more segments of rubber bands 72 , 74 , as described above. These segments of rubber bands will tend to bias the elevon in its neutral or central position. A coil 58 is mounted in wing 14 adjacent the hinge line between the wing and elevon 112 . This coil is of the type described above. A magnet 76 is attached to the leading edge of elevon 112 proximate coil 58 . As described above, energization of coil 58 with a first polarity will attract one pole of magnet 76 and result in commensurate movement of elevon 112 . When the polarity of the signal applied to coil 58 is reversed, the other pole of magnet 76 will be attracted and elevon 112 will be deflected in the opposite direction. As also described, a remote control receiver is mounted at an appropriate location within flying wing 100 to generate signals to coil 58 in response to signals transmitted from a transmitter.
[0046] Elevon 110 is similarly attached to wing 114 by segments of rubber bands 72 , 74 and is actuated by a similar coil 58 selectively energized to attract magnet 76 to produce upward or downward deflection of the elevon. Elevons 110 and 112 may be deflected in concert upwardly or downwardly to produce a change in pitch attitude of the flying wing. Alternatively, they may be deflected in opposite directions to provide a left or right rolling movement about the longitudinal axis of the flying wing.
[0047] Referring to FIG. 9 , there is illustrated the rear section of fuselage 12 , which may be part of the model plane shown in FIGS. 1 and 2 . For this reason, common elements will be assigned corresponding reference numerals. Rudder 24 is pivotally attached to vertical stabilizer 20 through segments of rubber band 72 , 74 . Upon actuation of coil 58 , a magnetic force will be created and magnet 76 responds thereto resulting in deflection of rudder 24 in one direction or the other as a function of the signal generated by a receiver mounted in fuselage 12 . Horizontal stabilizer 120 is attached to and supported by fuselage 12 . A single or a pair of elevators are pivotally attached to the horizontal stabilizer and deflection thereof, whether up or down, will result in a change in the pitch attitude of the model airplane. It is to be noted that elevators 122 , 124 work in concert, that is, upon command, both elevators deflect either upwardly or downwardly. Elevator 122 is pivotally secured to horizontal stabilizer 120 by a pair of segments of rubber bands 126 , 128 . These segments will bias the elevator into general alignment with the horizontal stabilizer and yet permit deflection in response to an imposed force. Similarly, elevator 124 is pivotally secured to the horizontal stabilizer by a pair of segments of rubber bands of which only rubber band 130 is illustrated. A coil 132 is mounted at hinge line 134 of horizontal stabilizer 120 . Magnet 136 is mounted at the leading edge of elevator 122 proximate to and under the influence of a magnetic field generated by coil 132 . Similarly, coil 138 is mounted proximate hinge line 140 of horizontal stabilizer 120 . Magnet 142 is mounted at the leading edge of elevator 124 proximate to and under the influence of a magnetic field generated by coil 138 . The function and operation of coil 132 and its magnet 136 and coil 138 and its magnet 142 are the same as that described above with respect to coil 58 and magnet 76 . Accordingly, a repetition of such function and operation need not be undertaken.
[0048] Upon transmission of a signal from a transmitter, coil 58 is selectively actuated to deflect rudder 24 to the left or right, as described above. Upon transmission of a further signal from the transmitter, coils 132 , 138 are energized to create a magnetic field of one polarity or the other. Magnets 136 , 142 will respond to such magnetic field and cause deflection of elevators 122 , 124 either up or down as a function of the polarity of the magnetic fields created. Such deflection of the elevators will result in a change in the pitch attitude of the model airplane.
[0049] FIG. 10 illustrates the tail of a model airplane of which a part of fuselage 12 is illustrated. The rear empennage mounted on fuselage 12 , as shown in FIG. 10 , is generally referred to as a V-tail. It includes two fixed stabilizers 150 , 152 , each of which is set at an angle with respect to horizontal in the range of about 30-45°. Each of these stabilizers includes a pivotally connected control surface 154 and 156 . Upon deflection of these control surfaces upwardly or downwardly, the pitch attitude of the model airplane will change to cause the airplane to climb or descend, respectively. Directional control is achieved by having the control surfaces deflect in opposite directions; that is, one control surface is deflected upwardly and the other one downwardly relative to the respective stabilizer. This will cause the model airplane to turn in the direction of the upwardly deflecting control surface. Thereby, control in the pitch and yaw axis will be achieved.
[0050] In the previous discussions of different model airplane configurations, the control-surfaces have been identified as either rudder, elevator or elevon; however, the term control surface would apply equally well to any of such elements.
[0051] Control surface 154 is secured to stabilizer 150 by segments of rubber bands 158 , 160 to bias the control surface in generally planar alignment with the stabilizer and yet accommodate deflection of the control surface. Similarly, control surface 156 is secured to stabilizer 152 by segments of rubber bands 162 , 164 accomplishing the same function and purpose. A coil 166 is mounted proximate hinge line 168 of stabilizer 150 . Magnet 170 is mounted at the leading edge of control surface 154 proximate coil 166 in order to be under the influence of a magnetic field created by the coil. Similarly, coil 172 is mounted proximate hinge line 174 of stabilizer 152 . Magnet 176 is mounted at the leading edge in sufficient proximity to coil 172 to be under any magnetic field generated by the coil.
[0052] In response to a signal from a transmitter and received by a receiver in the model airplane depicted in FIG. 10 , coils 166 and 172 will be energized to create a magnetic field of a first polarity resulting in movement of magnets 170 , 176 that will cause control surfaces 154 , 156 to be deflected upwardly. As noted above, such upward deflection will result in a change in pitch attitude of the model airplane. By transmitting a further signal to energize these coils to create a magnetic field of the opposite polarity, the resulting movement of magnets 170 , 176 will result in downward deflection of control surfaces 154 , 156 . By transmitting a yet further signal to be received by the receiver in the model airplane, coil 166 will produce a magnetic field opposite in polarity to that of the magnetic field produced by coil 172 . This will result in movement of magnet 170 and its control surface 154 in a direction opposite to that of control surface 156 due to the correspondingly opposite movement of magnet 176 . Such movement of the control surfaces will result in a change in direction of the model airplane. By transmitting a yet further signal, the polarity of coils 166 and 172 will be reversed and result in opposite deflection of the respective control surfaces to achieve a change in direction of the model airplane in the opposite direction.
[0053] Referring to FIG. 11 , there is shown representatively a transmitter 180 . This transmitter is similar to transmitter 30 , shown in FIG. 1A , except that additional signals are selectively transmitted. A pivotally secured control stick 182 is pivotally attached to the transmitter by a screw or bolt 184 . Upon up and down pivoting of the control stick, one of switches 186 , 188 will be engaged. Upon such engagement, a signal will be transmitted to the receiver in the model airplane and the receiver will decode the signal to energize coils 166 , 176 to cause either upward or downward deflection of control surfaces 154 , 156 and result in a change in pitch attitude of the model airplane. By deflecting control stick 182 to the left or right, switches 190 , 192 will be engaged. Such engagement will result in transmission of a signal from transmitter 180 to the receiver within the model airplane and decoded to energize coils 166 , 172 and create magnetic fields of different polarity to cause control surfaces 154 , 156 to deflect in opposite directions. Such movement of the control surfaces will result in a change in direction, left or right, of the model airplane. Accordingly, transmitter 180 provides the capability for 2-axis control of a model airplane. Such 2-axis control can be used with any of the model airplanes shown in FIGS. 6, 9 or 10 .
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A remotely controlled model airplane includes a receiver responsive to signals from a transmitter to control the direction of flight of the model airplane. The receiver, powered by a battery, demodulates the signal transmitted by the transmitter to selectively energize an electrical coil to generate a magnetic field of a first or second polarity. A rudder pivotally attached to the vertical stabilizer includes a magnet responsive to the magnetic fields generated and is urged in one direction or the other resulting in commensurate pivotal movement of the rudder. A hinge interconnecting the rudder and vertical stabilizer urges return to center of the rudder after it has been deflected left or right by the magnet responding to the magnetic field created as a result of a signal transmitted by the transmitter. An electric motor also under control of the transmitter and receiver may be incorporated to rotate a propeller to provide thrust and forward motion of the model airplane. By employing a transmitter to selectively transmit a plurality of signals, control surfaces of the model airplane can be deflected to provide 2-axis control to selectively alter the direction and pitch of the model airplane.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices and methods used to detect the locations at which the intensity of an optical image exceeds a threshold level, and more particularly to phase conjugate resonators employed in optical data processing.
2. Description of the Prior Art
There are many signal processing applications which require the processing of electrical data at a very high rate. The use of optics for these applications is very appealing because of the massive parallelism that can be obtained, i.e., a large amount of information can be processed using a single beam. One application of particular interest is the processing and detection of electronic signals by electro-optic correlation techniques. In these and various other applications it is desirable to employ a binary or threshold type of detection scheme which is sensitive to the optical signal at many different locations in the beam. The object is to detect whether the beam's optical intensity at one or more locations exceeds or falls below a threshold level, rather than to determine the absolute magnitude of the beam intensity at such locations.
For example, one may detect the occurrence of a particular alpha-numeric character by optically correlating a candidate character or a field of characters with every possible character, either in sequence or in parallel. The desired character will produce the highest correlation peak in the output of an optical correlator. In searching over a field of multiple correlations, the identification of normalized intensity peaks greater than a specified value thus identifies the character.
The intensity of a correlation peak could be simply detected with an optical detector and fed into an electronic threshold detector whose activated output then identifies a detection event. Unfortunately, neither the expected position of the character nor its associated correlation peak is generally known. Accordingly, a very large number of optical detectors, perhaps numbering in the tens of thousands, might be required to cover the entire field of possible positions. Each of the detectors must have fast temporal responses, especially if the occurrence event is short-lived. Furthermore, all of the detectors must have individual threshold circuits, since in general each detector produces a spurious output. Such outputs occur even with "noise-free" detectors, since large numbers of detectors typically see strong cross-correlation peaks which, though individually falling well below threshold, may in their total output exceed the threshold level (assuming the detector outputs are accumulated by summing over blocks of the outputs). Thus, one conventional approach is to use a large number of individual threshold circuits, one per detector.
At present, the detection of processed images is done with a fast detector array, such as a fast television camera, and complicated electronics are used to average over a set number of frames and compare the intensity to a pre-set threshold value. The equipment required to accomplish this function is complex, expensive and space consuming.
SUMMARY OF THE INVENTION
The principal object of the present invention is the accomplishment of spatial threshold detection by purely optical means, requiring only a single detector to determine whether one or more spatially distributed optical threshold events have occurred.
Another object of the invention is the achievement of optical image processing to enhance the portions of an image having an intensity on one side of a given threshold, and to reduce or entirely eliminate all other image elements.
Another object is the provision of an effective memory device capable of retaining high resolution, spatially distributed optical information for relatively long periods of time.
A further object is the achievement of a very low noise optical threshold detector for a large number of spatially distributed optical signals.
These objects are accomplished by employing a phase conjugate resonator (PCR) to perform spatial optical threshold detection. The PCR includes a phase conjugate mirror (PCM), another mirror optically opposed to the PCM, and an oscillation cavity between the two, possibly containing an active gain medium. An optical beam having a spatial intensity pattern is applied to the PCM such that a high intensity spatial PCR oscillation output is produced at locations corresponding to the beam locations with optical intensities on one side of a threshold level, and a low intensity (ideally zero) output at the other locations. The PCR is required to have a greater than unity gain capability for appropriate threshold event conditions, while an output optical detector is positioned to sense and obtain threshold event information from the PCR output. The PCM has a reflectivity greater than unity, and/or a gain medium is added to the oscillation cavity to bring the PCR gain above unity. The output detector may be designed to sense either the spatially resolved optical output from the PCR, or the cumulative area output.
In one embodiment, the optical image is imposed on one or both pump beams of a degenerate four-wave mixing PCM. Two cross-coupled PCMs can also be used, with the image imposed upon both pump beams of one PCM, and the pump beams of the other PCM providing a reference. The information modulated pump beams interact with the PCM to produce a high intensity output at locations corresponding to the pump beam locations at which the optical intensities are above the threshold level, and a low intensity output at locations corresponding to the pump beam locations at which the optical intensities are below the threshold level. The detector has been found to be capable of retaining its output for appreciable periods of time even after its input has been removed, and thus can function as an effective memory device.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings, in which:
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of one embodiment of the invention, in which optical information is imposed on the pump beam of a PCM;
FIGS. 2a and 2b are illustrative diagrams showing an input optical intensity pattern for the embodiment of FIG. 1, and the resulting output pattern, respectively;
FIG. 3 is an idealized graph illustrating the system's output response to the modulated pump beam's optical intensity at any particular location in the beam; and
FIG. 4 is a block diagram of another embodiment in which a pair of cross-coupled PCMs are used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
This invention results from the recognition that a PCR, if properly constructed, is capable of retaining and transferring high resolution spatial information. PCRs were developed fairly recently, and have been found to have several characteristics which differ significantly from those of conventional resonators. For example, a PCR can compensate for intracavity distortions and thus extract energy effectively in situations where conventional resonators require an unstable resonator design, and with an "ideal" PCM will not have longitudinal modes that depend on cavity length. PCR technology and operating characteristics are discussed in a paper by C. R. Giuliano, R. C. Lind, T. R. O'Meara and G. C. Valley, "Can Phase Conjugate Resonators Enhance Laser Performance?", Laser Focus, February, 1983, pages 55-64; and also in a paper by A. E. Siegman, P. A. Belanger and A. Hardy, "Optical Resonators Using Phase Conjugate Mirrors", Optical Phase Conjugation, R. A. Fisher, Ed. (Academic Press, N.Y. 1983).
The threshold detector of the present invention makes use of unique properties which have been discovered for a PCR. Specifically, PCRs have been found to have a very high degree of spatial resolution. With a properly designed system, such as those illustrated herein, they can be used to produce output beams in which each location or pixel of the output beam has a direct relationship to the corresponding location in one or more of the beams applied to the PCR.
A block diagram of a first system which employs a PCR as part of a spatial intensity threshold detector is shown in FIG. 1. The PCR, indicated by dash lines 2, consists of a phase conjugate mirror (PCM) 4, an output coupler 30 in the form of a mirror which is positioned opposite the PCM, and an oscillation cavity 8 between the PCM and output coupler. The PCM is of the degenerate four-wave mixing type, in which a pair of counterpropagating pump laser beams 10 and 12 are applied in opposite directions to an optical mixing medium 14.
Basically, a PCM produces a retro-reflection of an incident probe beam, with the phase of the reflected beam reversed from that of the incident beam. During PCM operation the probe and pump beams interfere in the non-linear mixing medium, producing an interference pattern. This pattern diffracts the pump beams, producing a signal wave which is the phase conjugate of the probe beam. In a PCR, scattered light from the pump beams in the mixing medium 14 travels across the cavity to the output coupler 30, where it is reflected back to the PCM. At the PCM the reflected scattered light is conjugated, amplified and reflected back to the output coupler; in this manner oscillation builds up to eventually produce a resonating beam oscillation within the cavity.
The pump beams are derived from a laser 16 whose output is directed by mirror 18 onto a beam splitter 20, and from there to the PCM as a pair of counterpropagating beams via mirrors 22 and 24. Laser 16 produces a coherent optical beam, the term "optical" being taken in its broad sense to indicate any wavelength at which a laser is capable of operating, not just the visible spectrum.
In accordance with the invention, a two-dimensional intensity profile is imposed on one of the pump beams 10, with the other beam having a substantially uniform intensity profile. This may be accomplished by passing the beam through a variable density mask or spatial light modulator 26 controlled by a two-dimensional image source 28, and imaging the beam onto the PCM by lens 29. Alternately, the same spatial information may be imposed on both pump beams and both beams imaged onto the PCM.
To establish oscillation within the PCR, it is necessary that the PCR gain be greater than unity. This can be accomplished by either employing a PCM whose reflectivity is sufficiently greater than unity, and/or by adding a gain medium to the resonating cavity. The PCM conjugating medium 14 for the FIG. 1 embodiment is, with the current state of the art, preferably a photorefractive material, in which case the reflectivity is dependent upon the ratio of the pump beam intensities. Thus, the threshold level can be controlled by varying the intensity of one or the other of the two pump beams.
The beam intensity at each individual pixel location in the modulated pump beam 10 determines whether oscillation will be established within the PCR at that location. PCR oscillation at each pixel location is generally independent of the presence or absence of oscillation at adjacent locations. Thus, a spatial oscillation pattern is established within the PCR which directly corresponds to the intensity profile of the modulated pump beam 10. Oscillation will be established at each pixel location for which the intensity of pump beam 10 exceeds a threshold level, whereas there will be no oscillation for pixel locations at which the intensity of modulated pump beam 10 is less than the threshold level.
The PCR produces an output through output coupler 30 at each pixel location where oscillation has been established. The spatial output from output coupler 30 is used to image the plane of the PCM onto a readout detector 32 (by a lens 34), the readout detector in turn providing an output to an electronic threshold detector 36. Alternately, mirrors or beam splitters could be placed in the oscillation cavity at an angle to the oscillating beam paths to provide an output by deflecting a portion of the resonating waves out of the cavity. Electronic threshold detector 36 generates a binary signal indicating the presence or absence of an optical output at each pixel location. For example, readout detector 32 could be an optical display, and threshold detector 36 a raster scanning device that converts the display array pattern to a series of binary electrical signals which indicate the presence or absence of an optical signal at each display pixel. Alternately, the detection apparatus could consist simply of a gross optical detector that accumulates the total area optical output from the PCR to indicate whether the output taken as a whole has exceeded a given threshold.
FIG. 2a shows an illustrative optical intensity pattern that could be imposed on the pump beam 10 of FIG. 1; the horizontal axis corresponds to distance across the beam while the vertical axis corresponds to the optical intensity at each pixel location. In practice, a much higher density of discrete optical intensities could be handled, and the pattern would be two-dimensional.
Dashed horizontal line 40 indicates the threshold oscillation level established by the ratio between the intensities of the two pump beams, the construction of the PCM and the presence or absence of any gain medium or variable loss in the oscillation cavity. The optical intensity exceeds the threshold level at pixel locations A, B and C, and is less than the threshold level at the pixel locations D, E, F, G and H. As described above, optical oscillation is established for those pixel locations at which the threshold level is exceeded. The resulting output pattern is illustrated in FIG. 2b. High intensity positive outputs 42, 44 are produced at those pixel locations at which the optical intensity threshold level is exceeded, while low intensity essentially zero outputs 46, 48 result from the pixel locations at which the optical intensity is less than the threshold level.
FIG. 3 is a graphical illustration of the intracavity response at each pixel location to the modulated pump beam intensity. In the idealized case there will be no oscillation at all, and accordingly zero PCR output, for all pump beam intensities below the threshold level. At the threshold the response would rise along a vertical trace, indicated by dash line 50, to a uniform output level which prevails for higher intensities. In practice, the PCR response is somewhat more gradual, as indicated by curved line 52.
Instead of a simple mirror, output coupler 30 could be a liquid crystal light valve (LCLV) such as that disclosed in U.S. Pat. No. 3,824,002 to Terry D. Beard, entitled "Alternating Current Liquid Crystal Light Valve" and assigned to Hughes Aircraft Company, the assignee of the present invention. In that case the spatial intensity information would modulate an input beam applied to the control input to the LCLV from outside the PCR, rather than to the PCM pump beams. As most LCLVs rely upon polarization rotation, a polarizer would be located on the cavity side of the LCLV. The polarizer would be selected so that light reflected from the LCLV is rejected on the cavity side except at those locations where the LCLV is actuated by the modulated input beam. The threshold level could be set by various means, such as by applying a light bias to the LCLV and/or setting the polarizer angle.
Another embodiment of the invention is illustrated in FIG. 4. A "folded" resonator is shown which consists of two PCMs 54, 56 and a curved output coupler mirror 58 which images one PCM onto the other. The upper PCM 54 is pumped with a pair of pump beams 60, 62, each of which contains the spatially modulated intensity pattern and are imaged onto PCM 54 by lenses 61 and 63, respectively. The lower PCM 56 is pumped with spatially uniform pump beams 64, 66 whose total intensity may be adjusted to provide a variable oscillation threshold. A neutral density filter 67 may be placed in one of the beam paths 66 to control the threshold. When one or more of the modulated pump beam pixel locations exceeds the threshold intensity, a corresponding number of oscillating modes are established within the PCR, and an output is directed onto the readout detector 32 through a lens 68. The provision of two cross-coupled PCMs helps to reduce diffraction losses and cross-talk.
The PCM conjugating medium for either embodiment is preferably a photorefractive material, although other media such as saturable absorbers might also be used. For photorefractive materials with a sufficiently high electro-optic coefficient, such as barium titanate (BaTiO 3 ) or strontium barium niobate (Sr 1-x Ba x Nb 2 O 6 ), the PCM will have a reflectivity sufficiently larger than unity to establish oscillation within the PCR. Other photorefractive materials with lower electro-optic coefficients may also be used in conjunction with reflectivity enhancement techniques such as frequency shifting or the application of an AC electrical field. The frequency shift technique is disclosed in an article by H. Rajbenbach and J. P. Huignard, "Optics Letters", vol. 10, page 137, March, 1985; the AC electric field technique is disclosed in a co-pending application by George Valley and Marvin Klein, "Self-Pumped Phase Conjugate Mirror and Method Using AC Field Enhanced Photorefractive Effect", Ser. No. 836,679, filed Mar. 5, 1986 and assigned to Hughes Aircraft Company, the assignee of the present invention. Typical materials that can be used in connection with such enhancement techniques are Bi 12 SiO 20 , Bi 12 GeO 20 , Bi 12 TiO 20 , GaAs and InP. A gain medium may also be added to the oscillation cavity to bring the PCR gain above unity if the PCM reflectivity is less than unity. The gain medium can generally be any medium suitable for establishing lasing action, such as a HeNe discharge.
The described system also functions as an effective memory device. With a relatively slow PCR response time, the spatial output pattern will persist for a period of time even after the pump beams have been removed. The use of barium titanate as a conjugating medium will provide a memory period of several seconds. In this manner the device can also be used as an optical memory. A spatial light modulator such as a liquid crystal light valve could be used to control the pump beam intensity modulation. When its spatially modulated input is removed, a liquid crystal light valve will produce an output of uniform intensity for the pump beam modulation. On the other hand, a substantial shortening of the PCM conjugating medium's response time will produce a correspondingly faster PCR response time that could make the system adaptable for real time applications.
The invention lends itself to numerous optical data processing applications. It can be used to determine when the optical intensity of any single pixel or group of pixels exceeds a prescribed but controllable threshold over a field of 10,000 pixels or more. Some applications for this high resolution capability include the detection of a convolution or correlation output, enhancement of an input beam's signal-to-noise ratio, incoherent-to-coherent conversion and contrast or image reversal and enhancement.
As numerous modifications and alternate embodiments will occur to those skilled in the art, it is intended that the invention be limited only in terms of the appended claims.
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A phase conjugate resonator (PCR) employing at least one phase conjugate mirror (PCM) provides high resolution spatial detection of individual locations in a two-dimensional optical array which exceed or fall below a threshold level. In one embodiment the optical intensity profile under investigation is imposed either onto one or both of the pump beams of a degenerate four-wave mixing PCM. In another embodiment a pair of PCMs are used as the two mirrors forming the PCR, with the pump beams for one PCM modulated and the pump beams for the other PCM serving as a threshold reference. In either case, the spatially modulated optical output may be read out with multiple detectors or an imaging system, or the cumulative area output of the PCR can be read out with a single detector to characterize the intensity profile relative to the threshold.
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FIELD OF THE INVENTION
[0001] The invention relates to the field of microbial enhanced oil recovery and bioremediation of subterranean contaminated sites. Specifically, it relates to methods of treating the toxic chemicals accumulated in subterranean sites adjacent to the water injection wells prior to introduction of microbial inocula for microbial enhanced oil recovery or bioremediation of these sites.
BACKGROUND OF THE INVENTION
[0002] Traditional oil recovery techniques which utilize only the natural forces present at an oil well site, allow recovery of only a minor portion of the crude oil present in an oil reservoir. Oil well site generally refers to any location where wells have been drilled into a subterranean rock containing oil with the intent to produce oil from that subterranean rock. An oil reservoir typically refers to a deposit of subterranean oil. Supplemental recovery methods such as water flooding have been used to force oil through the subterranean location toward the production well and thus improve recovery of the crude oil (Hyne, N.J., 2001, “Non-technical guide to petroleum geology, exploration, drilling, and production”, 2nd edition, Pen Well Corp., Tulsa, Okla., USA).
[0003] To meet the rising global demand on energy, there is a need to further increase production of crude oil from oil reservoirs. An additional supplemental technique used for enhancing oil recovery from oil reservoirs is known as Microbial Enhanced Oil Recovery (MEOR) as described in U.S. Pat. No. 7,484,560. MEOR, which has the potential to be a cost-effective method for enhanced oil recovery, involves either stimulating the indigenous oil reservoir microorganisms or injecting specifically selected microorganisms into the oil reservoir to produce metabolic effects that lead to improved oil recovery.
[0004] The production of oil and gas from subterranean oil reservoirs requires installing various equipment and pipelines on the surface or the subterranean sites of the oil reservoir which come in contact with corrosive fluids in gas- and oil-field applications. Thus, oil recovery is facilitated by preserving the integrity of the equipment needed to provide water for water injection wells and to convey oil and water from the production wells. As a result, corrosion can be a significant problem in the petroleum industry because of the cost and downtime associated with replacement of corroded equipment.
[0005] Sulfate reducing bacteria (SRB) microorganisms, which produce hydrogen sulfide (H 2 S), are amongst the major contributors to corrosion of ferrous metal surfaces and oil recovery equipment. These microorganisms can cause souring, corrosion and plugging and thus can have negative impact on a MEOR or a bioremediation process. Bioremediation refers to processes that use microorganisms to cleanup oil spills or other contaminants from either the surface or the subterranean sites of soil.
[0006] To combat corrosion, corrosion inhibitors which are chemicals or agents that decrease the corrosion rate of a metal or an alloy and are often toxic to microorganisms, are used to preserve the water injection and oil recovery equipment in such wells. In the practice of the present invention a water injection well is a well through which water is pumped down into an oil producing reservoir for pressure maintenance, water flooding, or enhanced oil recovery. The significant classes of corrosion inhibitors include compounds such as: inorganic and organic corrosion inhibitors. For example, organic phosphonates, organic nitrogen compounds, organic acids and their salts and esters (Chang, R. J. et al., Corrosion Inhibitors, 2006, Specialty Chemicals, SRI Consulting).
[0007] US2006/0013798 describes using bis-quaternary ammonium salts as corrosion inhibitors to preserve metal surfaces in contact with the fluids to extend the life of these capital assets.
[0008] U.S. Pat. No. 6,984,610 describes methods to clean up oil sludge and drilling mud residues from well cuttings, surface oil well drilling and production equipment through application of acids, pressure fracturing and acid-based microemulation for enhanced oil recovery.
[0009] WO2008/070990 describes preconditioning of oil wells using preconditioning agents such as methyl ethyl ketone, methyl propyl ketone and methyl tertiary-butyl ether in the injection water to improve oil recovery. Mechanisms such as modifying the viscosity of the oil in the reservoir and enlivening the heavy oil were attributed to this method.
[0010] US2009/0071653 describes using surfactants, caustic agents, anti-caking agents and abrasive agents to prevent or remove the build-up of fluid films on the processing equipment to increase the well's capacity.
[0011] Studies indicate that long-term addition of chemicals or agents used to control undesirable events such as corrosion, scale, microbial activities, and foam formation in the water supply of a water injection well does not lead to their accumulation in high enough concentrations to adversely affect the microorganisms used in MEOR (Carolet, J-L. in: Ollivier and Magot ed., “Petroleum Microbiology”, chapter 8, pages 164-165, 2005, ASM press, Washington, D.C.).
[0012] However, viability of microorganisms used in MEOR or bioremediation processes is a concern. It can be desirable to modify MEOR or bioremediation treatments such that the viability of microorganisms used is maintained throughout the process thus making them more effective.
SUMMARY OF THE INVENTION
[0013] The present disclosure relates to a method for improving the effectiveness of a MEOR or bioremediation process by detoxifying subterranean sites adjacent to oil wells, wherein the wells have been previously treated with corrosion inhibitors prior to inoculation of the microorganisms required for MEOR or bioremediation.
[0014] In one aspect the present invention is an oil recovery method comprising the steps of:
a) treating a subterranean site in a zone adjacent to a water injection well with a detoxifying agent wherein, prior to the treatment, corrosion inhibitors and/or their degradation products have been adsorbed into the zone and have accumulated to concentrations that are toxic to microorganisms used in microbial enhanced oil recovery and/or bioremediation processes, and thereby have formed a toxic zone; and b) adding an inoculum of microorganisms to the water injection well wherein the microorganisms comprise one or more species of: Comamonas, Fusibacter, Marinobacterium, Petrotoga, Shewanella, Pseudomonas, Vibrio, Thauera , and Microbulbifer useful in microbial enhanced oil recovery;
wherein the corrosion inhibitor is an inorganic compound selected from the group consisting of chlorine, hypochlorite, bromine, hypobromide, chlorine dioxide, hydrazine, anthraquinone, phosphates, and salts containing chrome, molybdenum, zinc, nitrates, nitrites and sodium sulfite.
BRIEF DESCRIPTION OF THE FIGURES
[0017] FIG. 1 is the schematic representation of a water injection well and the subterranean sites adjacent to the water injection well. ( 1 ) is the flow of injection water into the well casing ( 7 ), ( 2 and 3 ) are rock layers, ( 4 ) is the perforations in the casing, ( 5 ) is the well bore, ( 6 ) is the face of the rock layer made by the well bore, ( 7 ) is the well casing, ( 8 ) is one side of the watered zone that is axi-symmetric with the injection well, shown by a dotted box in the rock layer ( 3 ).
[0018] FIG. 2 is the schematic of a model system used to simulate formation of a toxic zone. ( 9 ) is a long slim tube; ( 10 ) is a pressure vessel to constrain the slim tube; ( 11 and 12 ) are the opposite ends of the pressurized vessel; ( 13 ) is a pump; ( 14 ) is the feed reservoir; ( 15 ) is the water inlet for the pressure vessel; ( 16 ) is the back pressure regulator; ( 17 ) is the high pressure air supply; ( 18 ) is an inlet fitting connecting the slim tube inside the pressure vessel to the pump and pressure transducers; ( 21 ) is an outlet fitting connecting the slim tube inside the pressure vessel to the back pressure regulator and the low side of the differential pressure transducer; ( 19 ) is a differential pressure transducer; and ( 20 ) is an absolute pressure transducer.
[0019] FIG. 3 depicts titration of amine coated core sand; ♦ represent amine coated sand and □ represent first derivative of the titration curve (central differences).
[0020] FIG. 4 depicts titration of brine and core sand with 1N HCl; ▪ represent brine #1 with 10 grams of core sand; diamonds ♦ represent brine #1 only; represents the slope of brine #1 with 10 grams of core sand; and Δ represents the slope of brine #1 only.
[0021] FIG. 5 depicts titration of brine and core sand with 10% nitric acid; ♦ represent the concentration of amine observed in solution for a given pH.
[0022] FIG. 6 depicts titration of brine and core sand with 10% acetic acid; ♦ represent the concentration of amine observed in solution for a given pH.
DETAILED DESCRIPTION OF THE INVENTION
[0023] In one aspect, the present invention is a method for detoxifying the corrosion inhibitors and their degradation products in a subterranean site adjacent to a water injection well of an oil well site. Applicants have found that oil recovery processing aids—such as corrosion inhibitors, for example—can accumulate in the area adjacent to the water injection well and build to concentrations that are toxic to microorganisms used in MEOR or bioremediation. As the term is used herein, “detoxifying” or “detoxification of” a water injection site means removing or reducing the toxicity caused by corrosion inhibitors and their degradation products to microorganisms to allow their growth and activity of said microorganisms, used in MEOR or bioremediation.
[0024] For the purposes of the present invention, the term “toxic zone” refers to a subterranean site adjacent to the water injection well comprising toxic concentrations of agents such as corrosion inhibitors or their degraded products which have adverse effects on growth and metabolic activities of microorganisms used in MEOR and/or bioremediation. A toxic agent, as the term is used herein, is any chemical or biological agent that adversely affects growth and metabolic functions of microorganisms used in MEOR and/or bioremediation.
[0025] FIG. 1 is a schematic of a subterranean site adjacent to a water injection well. The injection water ( 1 ) flows into the well casing ( 7 ) which is inside the well bore ( 5 ) drilled through rock layers ( 2 and 3 ). A gap exists between the well casing ( 7 ) and the face ( 6 ) of the rock layer made by the well bore ( 5 ). Rock layer ( 2 ) represents impermeable rock above and below a permeable rock ( 3 ) that holds or traps the oil. The injection water ( 1 ) flows down the well casing ( 7 ) and passes through perforations in the casing ( 5 ) and into fractures ( 4 ) in the permeable rock ( 3 ). This injection water then flows through the permeable rock layer ( 3 ) and displaces oil from a watered zone ( 8 ) adjacent to the well bore. This zone extends radially out from the well bore ( 5 ) in all directions in the permeable rock layer ( 3 ). While the volume of permeable rock ( 3 ) encompassed by the dash line ( 8 ) is illustrated only on one side of the well bore it actually exists on all sides of the well bore. This watered zone represents the subterranean site adjacent to the water injection well.
[0026] Corrosion inhibitors that can accumulate to levels that are toxic to microorganisms used in MEOR are, for example: inorganic corrosion inhibitors such as chlorine, hypochlorite, bromine, hypobromide and chlorine dioxide. Those used to combat corrosion caused by SRB microorganisms include, but are not limited to: nitrates (e.g., calcium or sodium salts), nitrite, molybdate, (or a combination of nitrate, nitrite and molybdate), anthraquinone, phosphates, salts containing chrome and zinc and other inorganics, including hydrazine and sodium sulfite (Sanders and Sturman, chapter 9, page 191, in: “Petroleum microbiology” page 191, supra and Schwermer, C. U., et al., Appl. Environ. Microbiol., 74: 2841-2851, 2008).
[0027] Organic compounds used as corrosion inhibitors include: acetylenic alcohols, organic azoles, gluteraldehyde, tetrahydroxymethyl phophonium sulfate (THPS), bisthiocyanate acrolein, dodecylguanine hydrochloride, formaldehyde, chlorophenols, organic oxygen scavengers and various nonionic surfactants.
[0028] Other organic corrosion inhibitors include, but are not limited to: organic phosphonates, organic nitrogen compounds including primary, secondary, tertiary or quaternary ammonium compounds (hereinafter referred to generically as “amines”), organic acids and their salts and esters, carboxylic acids and their salts and esters, sulfonic acids and their salts.
[0029] Applicants have determined that corrosion inhibitors can accumulate by adsorption into or on the subterranean site (e.g., sand stone, unconsolidated sand or limestone) or into the oil that has been trapped in the oil reservoir subterranean site. Long-term addition of these chemicals results in their accumulation and formation of a toxic zone in subterranean sites adjacent to the water well with adverse effects on microbial inocula intended for MEOR and/or bioremediation applications.
[0030] A model system to simulate formation of a toxic zone can be used to study its effects on the survival of microorganisms. For example, a model system called a slim tube can be set up and packed with core sand from an oil well site. The model system as described herein can be set up using tubing, valves and fittings compatible with the crude oil or the hydraulic solution used that can withstand the range of applied pressure during the process. An absolute pressure transducer, differential pressure transducer and back pressure regulator for Example made by (Cole Plamer, Vernon hill, IL and Serta, Boxborough, Mass.) are required and are commercially available to those skilled in the art.
[0031] The model toxic zone can be established using solutions of amines and/or amine mixtures and flushing them through a tube packed with core sand from an oil reservoir. Other corrosion inhibitors suitable for use in constructing a model can comprise organic phosphonates or anthraquinone or phosphates. The concentration of the corrosion inhibitors used to create the model toxic zone may be from 0.01 to 100 parts per million.
[0032] Detoxification of the toxic zone involves degradation, desorption or dispersion of the accumulated toxic chemicals or agents using detoxifying agents. The term “detoxifying agent” therefore refers to any chemical that either disperses or destroys the toxic chemicals and agents described herein and renders them non-toxic to microorganisms.
[0033] Detoxification of the chemicals accumulated in the toxic zone may be achieved using a degradation agent. A degradation agent, as the term is used herein, is an agent that destroys or assists in the destruction of toxic agents found in the toxic zone. Degradation agents can include, for example, strong oxidizers that chemically react with corrosion inhibitors when added to the injection water and degrade them into less toxic or non-toxic products. Degradation agents include strong oxidizing agents such as, for example, nitrates, nitrites, chlorates, percholorates and chlorites.
[0034] Detoxification of the chemicals accumulated at the toxic zone may also be achieved using a dispersing agent. A “dispersing agent” as the term is used herein includes any chemical that lowers the pH of the solution, ionizes the amines and solubilizes them into the water during water flooding and allows for natural dispersion and diffusion to lower the concentration where it is no longer toxic to MEOR or bioremediation microorganisms. For example, amines are fairly non-reactive under mild conditions, however, they become ionized at lower pH. Thus treatment of the amines with an acid increases their solubility and releases them from oil and/or from rocks and disperses them from the toxic zone. The solubilized amines may therefore enter into the water flowing through the well. A combination of radial flow, dispersion and desorption may allow the solubilized amines to be diluted and dispersed over a large area (from at least 10 to about 200 feet (from at least 3 meters to about 7 meters)) of the oil well. Following dilution and dispersion of the amines over a much larger area, their concentrations within the subterranean site of the well would have been consequently reduced to non-toxic levels for MEOR or bioremediation microorganisms. However, even if the amines concentrations were still at toxic levels, the toxic zone in the subterranean site adjacent to the injector well will have become non-toxic to microorganisms. Thus, the microbial inoculum may pass through the subterranean site adjacent to the water injection well without encountering toxic levels of the amines.
[0035] In another embodiment, hydrogen peroxide may be added to the toxic zone, as both a degradation and a dispersing agent, from about 1,000 parts per million to 70,000 parts per million by volume of water. In another embodiment, perchlorates may be added, as both a degradation and a dispersing agent, from about 1 parts per million to about 10,000 parts per million.
[0036] In another embodiment, any acid capable of lowering the pH at least 1 unit less than the equivalence point of the amine (as measured in the Examples below) may be used. The acid used to ionize the amines may include, but is not limited to, nitric acid, acetic acid, oxalic acid, hydrofluoric acid, and hydrochloric acid. Acid may be added from about 0.1 weight % to about 20 weight % to the water that is being pumped into the toxic zone.
[0037] In a MEOR process, viable microorganisms are added to the water being injected into the water injection well. The term “inoculum of microorganisms” refers to the concentration of viable microorganisms added. These microorganisms colonize, that is to grow and propagate, at the subterranean sites adjacent to the water injection well to perform their MEOR.
[0038] Microorganisms useful for this application may comprise classes of facultative aerobes, obligate anaerobes and denitrifiers. The inoculum may comprise of only one particular species or may comprise two or more species of the same genera or a combination of different genera of microorganisms.
[0039] The inoculum may be produced under aerobic or anaerobic conditions depending on the particular microorganism(s) used. Techniques and various suitable growth media for growth and maintenance of aerobic and anaerobic cultures are well known in the art and have been described in “Manual of Industrial Microbiology and Biotechnology” (A. L. Demain and N. A. Solomon, ASM Press, Washington, D.C., 1986) and “Isolation of Biotechnological Organisms from Nature”, (Labeda, D. P. ed. p117-140, McGraw-Hill Publishers, 1990).
[0040] Examples of microorganisms useful in MEOR in this application include, but are not limited to: Comamonas terrigena, Fusibacter paucivorans, Marinobacterium georgiense, Petrotoga miotherma, Shewanella putrefaciens, Pseudomonas stutzeri, Vibrio alginolyticus, Thauera aromatics, Thauera chlorobenzoica and Microbulbifer hydrolyticus.
[0041] In one embodiment an inoculum of Shewanella putrefaciens (ATCC PTA-8822) may be used to inoculate the slim tube test. In another embodiment Pseudomonas stutzeri (ATCC PTA8823) may be used to inoculate the slim tube. In another embodiment Thauera aromatica (ATCC9497) may be used to inoculate the slim tube.
[0042] The inoculum of microorganisms useful for bioremediation may comprise, but are not limited to, various species of: Corynebacteria, Pseudomonas, Achromobacter, Acinetobacter, Arthrobacter, Bacillus, Nocardia, Vibrio , etc. Additional useful microorganisms for bioremediation are known and have been cited, for example, in Table 1 of U.S. Pat. No. 5,756,304, columns 30 and 31.
[0043] The inoculum for injecting into the water well injection site may comprise one or more of the microorganisms listed above.
EXAMPLES
[0044] The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and make various changes and modifications to the invention to adapt it to various uses and conditions.
General Methods
Chemicals and Materials
[0045] All reagents, and materials used for the growth and maintenance of microbial cells were obtained from Aldrich Chemicals (Milwaukee, Wis.), DIFCO Laboratories (Detroit, Mich.), GIBCO/BRL (Gaithersburg, Md.), or Sigma Chemical Company (St. Louis, Mo.), unless otherwise specified.
Amines Analysis
[0046] Concentration of amines, in media and water, were analyzed by gas chromatography (GC). An Agilent Model 5890 (Agilent, Wilmington, Del.), GC equipped with a flame photoionization detector and a split/splitless injector, a DB-FFAP column (30 meter length×0.32 millimeter (mm) depth×0.25 micrometer particle size). The equipment had an Agilent ALS Autoinjector, 6890 Model Series with a 10 milliliter (ml) syringe. The system was calibrated using a sample of N,N-Dimethyl-1-Dodecaneamine (Aldrich). Helium was used as the carrier gas. A temperature gradient of 50 degrees Celsius (° C.) to 250° C. at 30° C. increase per minute (min) was used. Retention times (in minutes, min) for various chemicals of interest included: N,N-Dimethyl-1-Dodecaneamine (8.08 min); N,N-Dimethyl-1-Tetradecaneamine (8.85 min); N,N-Dimethyl-1-Hexadecane-amine (9.90 min); N,N-Dimethyl-1-Octadecaneamine (10.26 min) and N-Methyl,N-Benzyl)-1-Tetradecaneamine (11.40 min).
Example 1
Establishing a Toxic Zone in Core Sand from an Oil Well Using a Mixture of Amines in a Model System
[0047] A sample of the sand obtained from the Schrader Bluff formation at the Milne Point Unit of the Alaska North Slope was cleaned by washing with a solvent made up of a 50/50 (volume/volume) mixture of methanol and toluene. The solvent was subsequently drained and then evaporated off the core sand to produce clean, dry, flow able core sand. This core sand was sieved to remove particles with less than one micrometer in size and was then packed tightly into a four foot (121.92 cm) long flexible slim tube ( 9 ) and compacted by vibration using a laboratory engraver. Both ends of the slim tubes were capped to keep the core sand in it. The complete apparatus is shown in FIG. 2 . Tubing that can sustain the amount of pressures used in the slim tube, was connected to the end caps. The slim tube ( 9 ) was mounted into the pressure vessel ( 10 ) with tubing passing through the ends ( 11 and 12 ) of the pressure vessel using pressure fittings ( 18 and 21 ). Additional fittings and tubing were used to connect the inlet of the slim tube ( 11 ) to a pressure pump ( 13 ) and a feed reservoir ( 14 ).
[0048] Additional fittings and tubing connected the inlet of the slim tube to an absolute pressure transducer ( 20 ) and the high pressure side of a differential pressure transducer ( 19 ). Fittings and tubing connected the outlet of the slim tube ( 12 ) to the low pressure side of a differential pressure transducer ( 19 ) and to a back pressure regulator ( 16 ). The signals from the differential pressure and the absolute pressure transducer were ported to a computer and the pressure readings were monitored and periodically recorded. The pressure vessel ( 10 ) around the slim tube was filled with water through a water port ( 15 ). This water was then slowly pressurized with air ( 17 ) to a pressure of about 105 per square inch (psi) (0.72 mega Pascal) while brine #1 from the feed reservoir ( 14 ) (Table 1) flowed through the slim tube and left the slim tube through the back pressure regulator ( 16 ). This operation was performed such that the pressure in the slim tube was always 5 to 20 psi (0.034-0.137 mega Pascal) below the pressure in the pressure vessel ( 10 ).
[0000]
TABLE 1
Ingredients of Brine #1
(no nutrient brine - gram per liter (gr/L) of tap water
NaHCO 3
1.38
grams (gr)
CaCl 2 *6H 2 0
0.39
gr
MgCl 2 *6H 2 0
0.220
gr
KCl
0.090
gr
NaCl
11.60
gr
NaHCO 3
1.38
gr
Trace metals
1
ml
Trace vitamins
1
ml
Na 3 (PO 4 )
0.017
gr (=10 parts per million (ppm) PO 4 )
NH4Cl
0.029
gr (=10 ppm NH 4 )
Acetate
0.2
gr (200 ppm acetate)
The pH of brine #1 was adjusted to 7.0 with either HCl or NaOH and the solution was filter sterilized.
[0000]
TABLE 2
Concentration of the amines added to Brine #1
N-methylN-
Minor
other
NN-Dimethyl-1-
NN-Dimethyl-1-
NN-Dimethyl-
Benzyl-1-
amine
amine
Dodecaneamine
tetradecaneamine
Methanethioamide ??
Caprolactam
tetradecaneamine
Sample
PPM
PPM
PPM
PPM
PPM
PPM
PPM
Brine #1 w/ amine
25
124
23
1
0
0
2
[0049] Once the pressure inside and outside the slim tube was established, one pore volume of the crude oil from an oil reservoir of the Milne Point Unit of the Alaskan North Slope was pumped into the slim tube. This process was performed in several hours (h). Once the crude oil had saturated the core sand in the slim tube and was observed in the effluent, the flow was stopped and the oil was allowed to age in the core sand for 3 weeks. At the end of this time, brine #1 was pumped through the slim tube at a rate of ˜1.5-3.5 milliliter per hour (ml/h) (˜1 pore volume every 20 h). Samples were taken from the effluent and the concentration of natural microflora in them was determined.
[0050] After 51 pore volumes of flow through the slim tube the concentration of natural microflora in the system was about 1×10 7 colony forming units per milliliter (CFU/ml). At this point, a mixture of amines (hereafter amines/brine mixture) was added at 150 ppm concentration to brine #1. The approximate composition of the mixture of amines (Table 2) consisted of 7 different amine components that were identified. Five were identified by Mass Spectrometry (Agilent Technologies, Inc. Santa Clara, Calif.) as N-N-dimethyl-1-dodecaneamine, N-N-dimethyl-1-tetradecane-amine, N-N-dimethyl-methane-thioamide, caprolactam and N-methyl-N-benzyl-1-tetradecaneamine. Two of the components were identified as amines but specific chemical formulas could not be assigned to them because the Mass Spectral Fragmentation patterns could not be deciphered. These are labeled in Table 2 as “minor amine” and “other amine”. Analysis of the effluent from the slim tube did not indicate presence of any amines in it. The experiment was continued by pumping 150 ppm of the mixture of amines in brine #1 through the slim tube.
[0051] After 77 pore volumes of the mixture of brine #1 with 150 ppm of mixture of amines was pumped into the slim tube no amines were observed in the effluent.
[0052] After 80 pore volumes of the mixture of brine #1 with 150 ppm of mixture of amines was pumped into the slim tube a total of about 1 gr of the mixture of amines had flowed through the slim tube. At this point, 80 ppm of amines was finally observed in the effluent of the slim tube. This very long delay in seeing the amines in the effluent means that virtually all the amines had been trapped in the slim tube. In addition, at this time, no natural microflora could be seen in the effluent indicating that the slim tube had become toxic enough to kill all existing microflora. At this point, pumping the amines-free brine#1 was started in an attempt to flush the amines out of the slim tube and to make it less toxic.
[0053] After 24 pore volumes of the amines-free brine#1 had been pumped through the slim tube, 51 ppm of amines was detected in the effluent. The slim tube was then inoculated with one pore volume of Shewanella putrefaciens (ATCC PTA-8822) at a concentration of approximately 1×10 9 CFU/ml. This inoculation was not allowed to remain in the slim tube. Instead, amines-free brine#1 was flushed through the slim tube immediately after the inoculation. Consequently the microbes resided in the slim tube for only a few hours during the transit through it. Thus, it was anticipated that the microorganisms' concentration in the effluent could be measured in the effluent eluting the slim tube. However, remarkably no microorganisms (representing about a 9 log kill) were detected in the slim tube effluent despite the short residence time of the inoculum in the slim tube. This experiment confirmed that a toxic zone had been established in the slim tube. In a continued attempt to detoxify the slim tube, brine #1 alone was continuously pumped through it.
[0054] After 79 pore volumes of the amines-free brine #1 had been pumped through the slim tube, the amines concentration in the effluent of the slim tube was measured at 30 ppm. The slim tube was inoculated with another pore volume of Shewanella putrefaciens (at 1×10 9 CFU/ml). The CFU/ml in an effluent sample was about 1×10 4 showing more than a 5 log kill of this microorganism had occurred immediately following inoculation. This experiment underlined the continued toxic effect of the amines despite extended washing of the tube with the amines-free brine#1 solution.
[0055] After 108 pore volumes of the amines-free brine #1 had been pumped through the slim tube, the amine concentration in the effluent was measured at 5 ppm. The slim tube was inoculated with an additional one pore volume of Shewanella putrefaciens containing 1×10 9 CFU/ml. The CFU/ml in the effluent sample of the slim tube immediately following inoculation indicated a 4-5 log kill of this microorganism despite the extended washing with the amines-free brine#1 and the decrease in the amines concentration in the effluent. These results further confirmed the continued toxic effect of the mixture of amines accumulated in the slim tube.
[0056] After 143 pore volumes of the amines-free brine #1 had been pumped through the slim tube one pore volume of an inexpensive odorless mineral spirits (OMS) (Parks OMS, Zinsser Co., Inc., Somerset Jew Jersey #2035 CAS #8052-41-3) was pumped through the slim tube in an attempt to remove the remaining mixture of amines. After this flush of OMS, pumping of amines-free brine #1 through the slim tube was continued.
[0057] After 149 pore volumes of amines-free brine #1 had been pumped through the slim tube, the amines concentration in the effluent was measured at 4 ppm and the slim tube was inoculated with an additional one pore volume of Shewanella putrefaciens (1×10 9 CFU/ml). A count of microorganisms in the sample of the slim tube's effluent showed a 2-3 log kill (99 to 99.9%) despite the OMS flush and the extended washing with the amines-free brine#1. These results confirmed that the toxic zone in the slim tube was still killing virtually all the microorganisms added to the tube.
[0058] After 168 pore volumes of the amines-free brine #1 had been pumped through the slim tube, one pore volume of a solution of 10% HCl in water was pumped through the slim tube to remove the amines. After this acid wash, the amines-free brine #1 was continuously pumped through the slim tube.
[0059] Following the acid wash treatment, an additional 2 pore volumes of the amines-free brine #1 was pumped through the slim tube and the amines concentration in the effluent was measured at 0.5 ppm. The slim tube was then inoculated with an additional one pore volume of Shewanella putrefaciens (1×10 9 CFU/ml). The CFU/ml in the effluent showed about a 0.4 log kill of this microorganism. These results underlined survival of more microorganisms following the acid wash of the slim tube and the effectiveness of using an acid to detoxify the toxic zone in the slim tube. Table 3 below summarizes results of the various tests described above.
[0000]
TABLE 3
Summary of the amount of amine observed in the slim tube's
effluent and the fraction of the microorganisms killed
(log kill) during residence in the slim tube.
Total Pore volume
of fluid pumped
ppm amines
log kill after
through slim tube
in the effluent
inoculating
51
0
0
131
80.5
nd
amines flood stopped
155
51.1
9.6
210
29.5
5.3
(at least)
239
4.7
4.5
(at least)
274
OMS flooded ~1 pore volume
280
4.2
2.4
299
10% HCL flooded for 1 PV
301
0.5
0.4
PV = pore volume;
nd = not detected
Example 2
Removal of N N-Dimethyl-1-Dodecanamine from Core Sand Through their Ionization at Low pH Using Hydrochloric Acid
[0060] 38 milligrams (mg) of N N-Dimethyl-1-Dodecanamine (hereafter referred to as “the amine”) was added to 10.210 gr of Pentane. This solution was added to 10.1845 gr of specific sand layers (Oa and Ob) obtained from the Schrader Bluff formation of the Milne Point Unit of the Alaskan North slope. The oil content of the sand was first removed using a mixture of methanol and toluene (50/50, volume/volume) as solvent washes. The solvent mixture was subsequently evaporated off the core sand to produce clean, dry, flowable core sand. This sand was mixed with the amine and pentane solution to produce a slurry. This slurry was thoroughly mixed and the pentane was evaporated off leaving the amine on the sand (hereafter referred to as sand/amine mixture). 100 ml of brine #2 (Table 3) was added to the sand/amine mixture to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.4. The concentration of the amine in the water should have been 380 ppm if all the amine were dissolved in brine #2. Analysis of a sample of sand/amine/brine mixture by GC did not reveal the presence of any amines in the test sample (i.e., the amine conc. was ˜<1 ppm). The fact that the amine was not detected underlined its strong binding to the sand particles. 0.1 ml of 1 normal (N) HCl was added to this solution, and the pH and the amine concentration was measured again. This step was repeated several times and the analyses results are shown in both Table 4 and in FIG. 3 . Complete ionization and solubilization of the amine in the water was observed at pH below ˜6.0. This is a surprising finding since the pKa of HCl is −6.2 (Langes Handbook of Chemistry, 14 th edition, page 8.14, 1992, McGraw-Hill, Inc., New York). Therefore, the concentration of the HCl required for this step to completely ionize the amine and removed it from the toxic core sand may be further reduced several orders of magnitude from the 10% concentration used in this example. The data underlines the remarkable efficiency of an acid at ionizing and removing the amine from the sand.
[0000]
TABLE 3
Composition of brine #2 (gr/L of deionized water)
NaHCO 3
1.38 gr
CaCl 2 *6H 2 O
0.39 gr
MgCl 2 *6H 2 O
0.220 gr
KCl
0.090 gr
NaCl
11.60 gr
[0000]
TABLE 4
Amine concentration measured in Example 2
N-N-
First
dimethyl-1-
derivative
dodeanamine
(change in
(ppm) in slim
amine/change
1N HCl
sample
tube effluent
in pH)
pH
(ml)
Amine titrate st
0.00
8.14
0.00
Amine titrate 1
46.41
63.75
7.37
0.10
Amine titrate 2
59.29
63.42
7.21
0.10
Amine titrate 3
67.97
24.34
7.03
0.10
Amine titrate 4
74.38
160.35
6.59
0.10
Amine titrate 5
212.28
412.18
6.13
0.10
Amine titrate 6
288.72
679.86
6.07
0.10
Amine titrate 7
273.47
−148.78
6.04
0.05
Amine titrate 8
275.33
119.35
5.98
0.05
Amine titrate 9
303.31
65.90
5.79
0.05
Amine titrate 10
314.21
15.17
5.39
0.05
Amine titrate 11
328.48
3.24
4.13
0.05
Amine titrate 12
321.33
11.80
3.19
0.05
Amine titrate 13
342.88
47.42
2.91
0.05
Amine titrate 14
342.67
−6.52
2.74
0.05
Amine titrate 15
340.92
79.86
2.61
0.05
Amine titrate 16
369.02
80.22
2.41
0.10
Amine titrate 17
368.19
2.25
2.27
0.10
Amine titrate 18
369.54
7.51
2.18
0.10
Amine titrate 19
369.47
0.12
2.10
0.10
Amine titrate 20
369.56
2.04
0.10
Example 3
Capacity of Core Sand to Neutrilize Acid
A. Titration of Brine #2 in the Absence of Core Sand
[0061] The intent of this experiment was to determine the capacity of the core sand described in Example 2 to neutralize the HCl intended to ionize the amine accumulated in the sand.
[0062] To set up a control test, 100 ml of brine #2 was titrated with 1 N HCl to initial pH of 8.1. An aliquot (0.1 ml) of 1N HCl was added to the brine #2 and the pH was measured. The HCl addition was repeated several times and the pH was measured after each addition. Results of these analyses are shown in both Table 5 and in FIG. 4 . The data indicated that about 2.25 milliequivalents of HCl were needed to achieve the equivalence point of about pH 4 corresponding to about 100% recovery of the carbonate present in brine #2.
[0000] TABLE 5 Titration of synthetic injection brine #2 in the absence of the amine First derivative 1N HCl sample pH of pH (ml) Addition 1 8.10 0.00 Addition 2 7.67 0.73 0.10 Addition 3 7.37 0.49 0.10 Addition 4 7.18 0.35 0.10 Addition 5 7.02 0.29 0.10 Addition 6 6.89 0.23 0.10 Addition 7 6.79 0.21 0.10 Addition 8 6.68 0.19 0.10 Addition 9 6.60 0.17 0.10 Addition 10 6.51 0.15 0.10 Addition 11 6.45 0.15 0.10 Addition 12 6.36 0.18 0.10 Addition 13 6.27 0.18 0.10 Addition 14 6.18 0.18 0.10 Addition 15 6.09 0.17 0.10 Addition 16 6.01 0.17 0.10 Addition 17 5.92 0.18 0.10 Addition 18 5.83 0.19 0.10 Addition 19 5.73 0.33 0.10 Addition 20 5.50 0.32 0.10 Addition 21 5.41 0.33 0.10 Addition 22 5.17 0.74 0.10 Addition 23 4.67 1.94 0.10 Addition 24 3.23 1.86 0.10 Addition 25 2.81 0.62 0.10 Addition 26 2.61 0.36 0.10 Addition 27 2.45 0.25 0.10 Addition 28 2.36 0.17 0.10 Addition 29 2.28 0.10
B. Titration of Brine #2 with Core Sand
[0063] 100 ml of brine #2 plus 10 gr of the same core sand (brine/sand mixture) used in Example 2, was titrated with 1N HCl. The initial pH of the brine/sand mixture was 7.88. 0.1 ml aliquots of 1N HCl were added to this mixture repeatedly, and the pH was measured after each HCl addition. The results shown in both Table 6 and in FIG. 4 indicated that addition of 0.3 milliequivalents of HCl was needed to achieve the equivalence point with 10 gr of sand present. The data obtained in this experiment underlines the slight capacity of the core sand to neutralize the added HCl. Consequently a small concentration of an acid, such as HCl, ionized the amine associated with the core sand without getting neutralized by reaction with the sand.
[0000]
TABLE 6
Titration of brine #2 and 10 gr of core sand
Brine contained
Used 10.103 gr
1.87 gr NaHCO 3
of core sand
2.60 ml of 1N HCL
Slope of pH
ml
Sample
at pH
(first derivative)
1N HCl
1
7.88
0.00
2
7.55
0.53
0.10
3
7.35
0.36
0.10
4
7.19
0.30
0.10
5
7.05
0.24
0.10
6
6.95
0.20
0.10
7
6.85
0.18
0.10
8
6.77
0.18
0.10
9
6.67
0.17
0.10
10
6.60
0.14
0.10
11
6.53
0.14
0.10
12
6.46
0.13
0.10
13
6.40
0.12
0.10
14
6.34
0.13
0.10
15
6.27
0.13
0.10
16
6.21
0.13
0.10
17
6.14
0.15
0.10
18
6.06
0.16
0.10
19
5.98
0.16
0.10
20
5.90
0.17
0.10
21
5.81
0.21
0.10
22
5.69
0.29
0.10
23
5.52
0.34
0.10
24
5.35
0.45
0.10
25
5.07
0.80
0.10
26
4.55
1.14
0.10
27
3.93
1.13
0.10
28
3.42
0.86
0.10
29
3.07
0.52
0.10
30
2.90
0.33
0.10
31
2.74
0.24
0.10
32
2.66
0.29
0.10
33
2.45
0.34
0.20
34
2.32
0.23
0.20
35
2.22
0.18
0.20
36
2.14
0.20
Example 4
Removal of N-N-Dimethyl-1-Dodecanamine from Core Sand Through their Ionization at Low pH Using 10% Nitric Acid
[0064] The procedure outlined in Example 2 was used to produce the sand/amine mixture except that 519 mg of the amine, 10 gr of Pentane. and 60.062 gr of sand from the Oa and Ob layers were used. 29.065 gr of this sand/amine mixture was added to 100 ml of brine #2 (Table 3) to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.28. The concentration of the amine in the water should have been about 2000 ppm if all the amine was dissolved in brine #2. Instead, analysis of a sample of brine #2 in contact with the sand/amine/brine mixture as described above showed that the amine concentration was ˜85 ppm, i.e., far less than what was expected. The fact that only a small amount of the amine was detected in brine #2 underlined the strong binding of the amine to the sand particles. 0.1 ml of 10 weight percent (wt %) nitric acid in water was added to this solution, and the pH and the amine concentration were measured again. This step was repeated several times and the analyses results are shown in both Table 7 and in FIG. 5 . Complete ionization and solubilization in the water of the amine was observed at a pH below ˜6.7. This is a surprising finding since the pKa of nitric acid is −1.37 (Langes Handbook of Chemistry, 14 th edition, page 8.15, 1992, McGraw-Hill, Inc., New York), the concentration of the nitric acid required for this step may be further reduced several orders of magnitude from the 10 wt % used in this experiment without any negative impact on removal of the amines from the core sand.
[0000]
TABLE 7
Amine concentration measured in Example 4
ppm
N-N-dimethyl-1-
ml
sample
dodeanamine
pH
10% HNO 3
start
85
8.28
0
1
110
8.13
0.1
2
211
7.72
0.1
3
216
7.42
0.1
4
235
7.25
0.1
5
540
7.2
0.1
6
745
7.29
0.1
7
1153
7.33
0.1
8
1210
7.29
0.1
9
1327
7.18
0.1
10
1315
7.11
0.1
11
1413
6.99
0.1
12
1667
6.85
0.1
13
1897
6.73
0.1
14
1853
6.64
0.1
15
1858
6.59
0.1
16
1788
6.28
0.2
17
1822
5.8
0.2
18
1975
3.46
0.2
Example 5
Removal of N-N-Dimethyl-1-Dodecanamine from Core Sand Through its Ionization at Low pH Using 10% Acetic Acid
[0065] The same procedure outlined in Example 4 was repeated here to produce the sand/amine mixture. 30.85 grams (gr) of the sand/amine mixture was added to 100 ml of brine #2 (Table 3) to create the sand/amine/brine mixture. The initial pH of the sand/amine/brine mixture was 8.52. The concentration of the amine in the water should have been about 2000 ppm if all the amine were dissolved in brine #2. Instead, analysis of brine #2 in contact with the sand/amine/brine mixture, as described above, showed that the amine concentration was ˜67 ppm, i.e., far less than what was expected. The fact that only a small amount of the amine was detected in the brine #2 underlined the strong binding of the amine to the sand particles. 0.1 ml of 10 wt % acetic acid was added to this solution, and the pH and the amine concentration were measured again. This step was repeated several times and the analyses results are shown in both Table 8 and in FIG. 6 . Complete ionization and solubilization in the water of the amine was observed at pH below ˜6.7. This is a surprising finding since the pKa of acetic acid is 4.756 (Langes Handbook of Chemistry, 14 th edition, page 8.19, 1992, McGraw-Hill, Inc., New York). Consequently, the concentration of the acetic acid required for this step may be further reduced significantly from what was used in this example without any negative impact on removal of the amine from the core sand.
[0066] The observations described above illustrate that a weak organic acid, like acetic acid can be as effective as a strong inorganic acid, like hydrochloric acid, at ionizing and separating the amines from the toxic core sand. It can therefore be concluded that to remove the toxic zone from a subterranean site, any acid that decreases the pH of a solution below about 6.7 can be used.
[0000]
TABLE 8
Amine concentration measured in Example
ppm
N-N-dimethyl-1-
ml
sample
dodeanamine
pH
10% acetic acid
start
67
8.52
0
1
63
8.01
0.1
2
107
7.41
0.1
3
215
7.4
0.1
4
497
7.37
0.1
5
512
7.23
0.1
6
969
7.12
0.1
7
1239
6.98
0.1
8
1453
6.89
0.1
9
1583
6.75
0.1
10
1579
6.56
0.1
11
1616
6.39
0.1
12
1759
6.4
0.1
13
1736
6.02
0.2
14
1718
5.4
0.2
15
1743
5.04
0.2
16
1931
4.86
0.2
17
1995
4.73
0.2
18
1913
4.61
0.2
19
1881
4.52
0.2
20
1837
4.43
0.2
21
1885
4.36
0.3
|
A method to improve the effectiveness of MEOR or bioremediation processes has been disclosed. In this method toxic chemicals accumulated in subterranean sites adjacent to the water injection wells are either dispersed or removed prior to introduction of microbial inocula for enhanced microbial oil recovery or bioremediation of these sites.
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DESCRIPTION
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,029,549 discloses and claims the use of Mycobacterium fortuitum NRRL B-8119 to make 9-hydroxy-3-oxo-4-pregnene-20-carboxylic acid [9-hydroxybisnoracid]. The same microbe is used to make 9-hydroxy-4-androstene-3,17-dione [9-hydroxyandrostenedione] in U.S. Pat. No. 4,035,236; and 9-hydroxy-3-oxo-4-pregnene-20-carboxylic acid methyl ester [9-hydroxybisnoracid methyl ester] in U.S. Pat. No. 4,214,051.
European Patent Application 79104372.2 discloses a two-stage fermentation for preparing 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid (I) which is useful as an intermediate in the synthesis of valuable corticoids. This process entails first the conversion of sterols to 3-oxo-4,17(20)-pregnadiene-20-carboxylic acid by fermentation with Mycobacterium strain NRRL B-8054, and then conversion of this compound to (I) by incubation with any one of several microorganisms capable of introducing a hydroxyl group in the 9α position.
BRIEF SUMMARY OF THE INVENTION
Disclosed and claimed is an efficient one-stage fermentation process for preparing the useful intermediate 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid (I). This process is conducted by use of a novel mutant of M. fortuitum NRRL B-8119. The subject invention process also encompasses the use of novel double mutants obtained from the genera of microorganisms disclosed in U.S. Pat. No. 4,029,549, i.e., Arthrobacter, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, Mycobacterium, Nocardia, Protaminobacter, Serratia, and Streptomyces. The microorganisms of these genera are all well known sterol degraders. The wild type strains of these genera degrade sterols non-selectively to small molecular weight compounds, e.g. CO 2 +H 2 O. Mutants can be made from these wild types by following the procedures disclosed in U.S. Pat. No. 4,029,549, Example 1. This example discloses the preparation of M. fortuitum NRRL B-8119.
Mutants of the genera, disclosed above, which can be made by using the procedures of Example 1 of U.S. Pat. No. 4,029,549, can then be subjected to the mutation procedures, disclosed herein, to prepare further mutants. These latter mutants, as exemplified here by M. fortuitum NRRL B-12433, can be used in the one-stage fermentation process, disclosed herein, to prepare compound (I).
The subject one-stage fermentation process is a vast improvement over the two-stage process for preparing compound (I) discussed supra.
DETAILED DESCRIPTION OF THE INVENTION
The Microorganisms
Mutants which are characterized by their ability to selectively degrade steroids having 17-alkyl side chains and accumulate 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid (I) as a major product in the fermentation beer can be obtained by mutating microorganisms of the following genera: Arthrobacter, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, Mycobacterium, Nocardia, Protaminobacter, Serratia, and Streptomyces.
Following is an example of the preparation of the novel mutant used in the subject one-stage fermentation process. The mutant prepared in this example is M. fortuitum NRRL B-12433. Similar mutants from other Mycobacterium species and other microbe genera, as recited herein, can be prepared by following the procedures of the following example.
Preparation of a mutant which accumulates 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid as a major product of the degradation of sterols
Mycobacterium fortuitum NRRL B-8119 is grown at 31° in a medium consisting of (per liter) nutrient broth, 8 g; yeast extract, 1 g; glycerol, 5 g; Tween 80, 0.1% (w/v); and distilled H 2 O. This medium is sterilized by autoclaving at 15 lb/in 2 for 20 min. The cells are grown to a density of about 5×10 8 per ml, and then collected on a sterile 0.2 micron filter. The cells are washed with an equal volume of sterile 0.1 M sodium citrate, pH 5.6 containing 0.1% Tween 80, and then resuspended in 1/2 volume of the same buffer. N-methyl-N'-nitro-N-nitrosoguanidine is added to a concentration of 100 μg/ml and the cell suspension is incubated at 31° C. for 1 hr. The cells are then washed with 2 volumes of sterile, 0.1 M potassium phosphate buffer, pH 7 containing 0.1% Tween 80, and then resuspended in 1 volume of the same buffer. A medium is prepared containing (per liter) nutrient broth, 8 g; NaCl, 5 g; glycerol, 5 g; and distilled H 2 O. Agar is added to 15 g/l and the medium is autoclaved at 15 lb/in 2 for 20 min and then poured into sterile Petri dishes. The mutagenized cells are then plated on this medium and colonies which grow on these plates are subsequently screened in small scale fermentations for their ability to convert sterols to compound (I). Detection of the desired compound is by thin layer chromatography of methylene chloride extracts of the test fermentations, using silica gel and the solvent system methylene chloride-acetone-acetic acid (212-38-1). In this manner, mutant NRRL B-12433 is isolated which accumulates 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid as a major product of the bioconversion of sterols.
The key to isolating a mutant like the one described herein is to start with a mutant, such as NRRL B-8119, which is already blocked in steroid ring degradation so that it produces 9α-hydroxyandrostenedione, and introduce into this microorganism a second mutation affecting sterol side chain degradation.
Description of the Microorganism
The mutant bringing about the biotransformation described herein differs from its parent culture, e.g., Mycobacterium fortuitum NRRL B-8119, only in its action on steroid molecules. In all other respects, such as morphology and drug sensitivities, they are similar if not identical. Both M. fortuitum cultures are acid-fast non-motile, non-sporulating bacilli belonging to the family Mycobacteriaceae of the order Actinomycetales. According to Runyon's classification, Runyon, E. H., 1959 Med. Clin. North America 43:273, it is a nonchromogenic group IV mycobacterium, i.e., it grows rapidly at low temperature to produce nonpigmented colonies on relatively simple media.
M. fortuitum NRRL B-8119 and NRRL B-12433 have been deposited in the permanent collection at the Northern Regional Research Laboratory, U.S. Department of Agriculture, Peoria, Ill., U.S.A. M. fortuitum NRRL B-8119 has been available to the public at least since issuance of the above-mentioned U.S. patents disclosing the microbe. M. fortuitum NRRL B-12433 was deposited on May 4, 1981. Subcultures of these microorganisms are available from the NRRL depository by request made thereto. It should be understood that the availability of the culture does not constitute a license to practice the subject invention in derogation of patent rights granted with the subject instrument by governmental action.
Compound (I) is useful as an intermediate in the synthesis of valuable corticoids. For example, it can be converted to hydrocortisone acetate by following the procedure detailed in published European Patent Application 79104372.2.
Following are examples which illustrate the one-stage fermentation process of the subject invention. These examples are merely illustrative, and, thus, should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.
Example 1--Fermentation of Crude Sitosterol
The biotransformation medium contains (per liter) Ucon, 8.0 g; Cerelose, 5.0 g; NH 4 Cl, 3.0 g; CaCO 3 , 3.0 g; Na 3 [citrate].2H 2 O, 3.0 g; Tween 80, 2.0 g; soyflour, 1.0 g; KH 2 PO 4 , 0.5 g; urea, 0.5 g and crude sitosterol, 30.0 g in tap water with the pH adjusted to 7.0. Flasks containing 100 ml portions of this medium are innoculated with 10 ml of seed cultures of M. fortuitum NRRL B-12433, grown at 28° in a medium containing (per liter) nutrient broth, 8.0 g; glycerol, 5.0 g; yeast extract, 1.0 g and Tween 80, 1.0 g in distilled water with the pH adjusted to 7.0. The cultures are then incubated at 28° for 336 hr on a rotary shaker. Following incubation, the mixture is extracted and the product isolated as detailed below in Example 3.
Example 2
Just as in Example 1, but with various steroidal substrates provided singly or in combination and in pure or crude form. Such substrates include sitosterol, cholesterol, stigmasterol and campesterol.
Example 3--Isolation of (I) from M. fortuitum NRRL B-12433 Fermentation
Fermentation beer (1200 ml) from a sitosterol bioconversion using M. fortuitum NRRL B-12433 is acidified and extracted twice with an equal volume of methylene chloride (MeCl 2 ), giving 29.2 g and 8.9 g crude extract respectively.
The first extract is redissolved in MeCl 2 and washed with saturated sodium bicarbonate solution. The aqueous washes are pooled, acidified with dilute HCl (4-N) and back-extracted with MeCl 2 . The extract is dried over magnesium sulfate and filtered. Evaporation of the solvent leaves a yellow solid that is triturated with MeCl 2 to give a pale yellow powder. This is crystallized from a mixture of MeCl 2 and methanol, from which three successive crops are obtained: (a) 3.8 g; (b) 2.1 g; and (c) 2.8 g. These are shown by nmr spectrometry to be mixtures of acids with the Δ 17 (20) -dehydro compound (I) in concentrations of 90%, 35%, and 10%, respectively.
Three recrystallizations of the first crop from MeCl 2 /MeOH gives 1.8 g of 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid (I), mp 240°-242°, [α] D 40.7° (methanol). The mass spectrum gives a molecular ion at m/e 358 (C 22 H 30 O 4 ).
Example 4
By substituting a sterol-degrading microorganism from the genera Arthrobacter, Bacillus, Brevibacterium, Corynebacterium, Nocardia, Protaminobacter, Serratia, and Streptomyces, for Mycobacterium fortuitum NRRL B-8119 in the process disclosed for preparing M. fortuitum NRRL B-12433, there are obtained mutant microorganisms which are characterized by their ability to selectively degrade steroids with a C-17 side chain and accumulate compound (I) as a major product.
Example 5
By substituting the mutants obtained in Example 4 for M. fortuitum NRRL B-12433 in Example 1, there is obtained compound (I).
|
The subject invention concerns a novel one-stage fermentation process for making the useful steroid intermediate 9-hydroxy-3-oxo-4,17(20)-pregnadiene-20-carboxylic acid (I). This process is significantly superior to the best prior art process known for making (I).
| 8
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FIELD OF INVENTION
The invention generally relates to technique for processing frames in a network switch. In particular, the invention relates to a system and method for providing distributed VLAN association, policing, shaping, and statistics acquisition in a plurality of data link layer controllers of the network switch.
BACKGROUND
Routers in packet switched networks generally employ one or more network processors, typically an application-specific integrated circuit (ASICs), to perform various packet processing operations. Each network processor is generally associated with a plurality of media access controllers from which frames are received and to which frames are transmitted. Historically, the routers were designed so that the network processor could simultaneously accommodate traffic from each of the associated ports being operated at its designated wire speed, typically 100 or 1000 megabits/sec. There is, however, a trend to over-subscribed ports, meaning that the bandwidth of the network processor or other router resources is generally unable to support each of the ports operating at wire speed for a sustained period of time. While the per-port cost savings for an over-subscribed system provides a beneficial tradeoff for some customers, oversubscribing ports may lead to some loss of data as a result of the inability of the network processor or route processor to handle the traffic.
In order to minimize the detrimental effects of over-subscription, routers may employ extensive buffering in an attempt to capture bursts of traffic until the resources are available to processes the traffic. Pause messages may also be transmitted to one or more link partners to temporarily reduce the amount of data received and thereby reduce the chance of buffer overflow. Despite limited success, both of these approaches fail to address the underlying inability of the network processor or other resources to handle large volumes of traffic. There is therefore a need for a means of maintaining the advantages of oversubscribed port configurations while reducing the computational demands on the network processor.
SUMMARY
The present invention features a data link layer processor for performing traffic shaping of egress traffic flows integrally with one or more media access controllers (MACs). Identifying and discarding out-of-profile frames subsequent to routing operations in a network processor reduces the computational burden carried by the network processor and allows for improved throughput in switching devices in which the network processor bandwidth is oversubscribed.
The data link layer processor in some embodiments comprises one or more MACs, and a traffic shaper, operatively coupled to the one or more MACs, for discarding one or more frames that exceed a bandwidth requirement prior to transmission to the MACs. In some embodiments, the traffic shaper makes discard decisions in accordance with a Three Color Marker (TCM) algorithm, such as the single rate TCM and two rate TCM. The data link processor may employ a flow search engine including a content addressable memory (CAM), for example, for classifying the traffic based upon one or more properties associated with the frames. The CAM is preferably programmed with Quality of Servic (QoS) rules pertaining to the associated ports of the particular data link layer processor, which is generally significantly less than the number of QoS entries needed by a network processor to support shaping for all ports of the switching device.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which:
FIG. 1 is a functional block diagram of network switching device, in accordance with the preferred embodiment of the present invention;
FIG. 2 is a functional block diagram of an access module, in accordance with the preferred embodiment of the present invention;
FIG. 3 is a functional block diagram of a Data Link Layer processor, according to the preferred embodiment of the present invention;
FIG. 4 is a functional block diagram of an integral traffic policer employed by the Data Link Layer processor, according to the preferred embodiment of the present invention
FIG. 5 is a schematic diagram of the flow database present employed by the Data Link Layer processor, according to the preferred embodiment of the present invention; and
FIG. 6 is a functional block diagram of an integral VLAN pop module employed by the Data Link Layer processor, according to the preferred embodiment of the present invention.
DETAILED DESCRIPTION
Illustrated in FIG. 1 is a functional block diagram of network switching device with which the preferred embodiment may be implemented. The switching device 100 in the preferred embodiment is adapted to perform switching and routing operations with protocol data units (PDUs) at layer 2 (Data Link Layer) and layer 3 (Network Layer) as defined in the Open Systems Interconnect (OSI) reference model. The switching device 100 is preferably one of a plurality of switching devices operatively coupled to one another via a common switch fabric (not shown). The switching devices are, in turn, operatively coupled to a plurality of nodes in a data communications network embodied in a local area network (LAN), wide area network (WAN), metropolitan area network (MAN), or a combination thereof, for example.
The switching device 100 of the preferred embodiment generally comprises a network processor 130 , e.g., a route processor, a queue or traffic manager 140 , and a management module 150 . The network processor 130 is operatively coupled to the network via a plurality of network access modules (AMs) 102 , each of the AMs 102 including at least one external port operatively coupled to a communications link for purposes of receiving ingress data traffic and transmitting egress data traffic. As used herein, traffic entering the switching device 100 at the AMs 102 is referred to as ingress traffic while traffic exiting at an AM 102 is referred to as egress traffic. The AM 102 ports include Data Link Layer ports such as Ethernet media access control (MAC) interfaces enabled with Institute of Electrical and Electronics Engineers (IEEE) standard 802.3, for example.
The PDUs of the ingress and egress traffic are conveyed between the plurality of AMs 102 and network processor 130 via one or more internal data buses 106 . The network processor 130 of the preferred embodiment comprises a classifier 132 and a forwarding processor 134 , and an egress processor 136 . The classifier 132 generally parses ingress PDUs; extracts one or more fields of the PDU including source and or destination addresses, protocol types, and priority information; and maps the PDU to one of a set of flow categories based upon local policies defined by a network administrator via the management module 150 . The local policies prescribe the class of service (CoS) and or quality of service (QoS) to be applied the PDU.
The forwarding processor 134 then prepares the ingress PDU for transmission using address information compiled by the switching device 100 . If the destination physical address of the PDU is matched in the MAC address tables, the appropriate output port is identified and the frame is switched to the egress port of the appropriate egress switching device. If, however, the PDU includes a destination network address of a node in another network domain, the forwarding processor searches known Internet Protocol (IP) addresses and other flow information in a forwarding table retained in a central Content Addressable Memory (cCAM), for example; retrieves, if a match occurs, the next-hop MAC address of an adjacent device to which the packet is to be forwarded; and encapsulates the packet in a new layer 2 header. The PDUs of the ingress flow are then passed from the network processor 130 to the queue manager 140 where they are buffered prior to transmission to the switch fabric (not shown) via the fabric interface module 104 .
In addition to the ingress processing described above, the network processor 130 also processes egress traffic received from the switch fabric. In support of this egress traffic, the network processor 130 further includes an egress processor 136 that receives egress traffic from the egress queue memory 146 or fabric interface module 104 that may be temporarily buffered prior to being passed to the designated egress port among the AMs 102 .
The queue manager 140 comprises at least one ingress queue memory 142 and queue scheduler 144 . The ingress queue memory 142 includes a plurality of packet buffers or queues, each of which is associated with a different priority level or a different level of QoS/CoS. When output bandwidth is available, a buffered PDU is transmitted by the scheduler 144 to the switch fabric via the fabric interface module 104 .
Illustrated in FIG. 2 is a functional block diagram of an AM 102 , in accordance with the preferred embodiment. The AM 102 generally comprises a plurality of physical layer interfaces (PHY) 240 and a MAC processor 200 . Each of the PHYs 240 operating at layer 1 (Physical Layer) defined in the OSI reference model performs conventional network interface functions including the reception and transmission of Ethernet symbol streams. When receiving a symbol stream from the associated communications link, electrical or optical signals from the communications link are converted by the PHY 240 to a byte stream which is then transmitted to an associated MAC interface 210 . In the transmit mode, the PHY 240 converts a byte stream from an associated MAC interface 210 into the electrical or optical signal appropriate for the medium. The PHY 240 is particular to the type of medium to which it is connect.
The MAC processor 200 in the preferred embodiment comprises one or more MAC interfaces 210 compliant with the IEEE standard 802.3, hereby incorporated by reference. The MAC interfaces 210 , operating at layer two defined in the OSI reference model, perform conventional network interface functions including the reception and transmission of Ethernet frames. In reception mode, the MACs 210 preferably perform various functions including: (a) MAC frame parsing for extracting from the Ethernet Type/Length field, the encapsulated protocol type, the frame priority, the user priority of VLAN tagged frames, and the TOS byte of IP frames with precedence or DiffServ mapping; (b) error checking using the frame check sequence (FCS) value of received data as well as packet decapsulation; and (c) asymmetric and symmetric flow control including the acceptance of flow control frames to discontinue frame transmission or pause frame transmission by a network neighbor, for example. Frames from the MAC interfaces 210 then undergo local processing at the MAC preprocessor 220 before being transmitted to the network processor 130 .
In the transmission mode, frames undergo local processing at the MAC postprocessor 230 prior to being transmitted to the MAC interfaces 210 . Consistent with conventional media access controllers, the MAC interfaces 210 perform various functions including: (a) collision handling, (b) access control to the communications medium in accordance with the CSMA/CD transmission protocol, (c) frame check sequence (FCS) value generation, (d) encapsulation, and (e) transmit deferral, for example. In the preferred embodiment, the MAC interfaces 210 are adapted to independently support either 10, 100, or 1000 megabit per second throughput using Reduced Ten-Bit Interface (RTBI) or Reduced Gigabit Media Independent Interface (RGMII) types of interfaces.
Illustrated in FIG. 3 is a functional block diagram of a MAC processor 200 , according to the preferred embodiment of the present invention. In addition to one or more MACs 210 , the MAC processor 200 in some embodiments includes a MAC preprocessor 220 and a MAC postprocessor 230 . The MAC preprocessor 220 generally includes a traffic policer 304 for selectively filtering frames, a MAC buffer 306 , a VLAN push module 308 for appending VLAN tags to selected inbound frames, a rate buffer 312 , and an ingress bus transmitter 314 for conveying the frames to the network processor 130 . The MAC postprocessor 230 preferably includes an egress bus receiver 320 , a rate buffer 322 adapted further shape the egress traffic, and a VLAN pop module 326 for removing VLAN tags to selected inbound frames.
Ingress frames are transmitted from the plurality of MACs 210 to one or more receiver buffers via the internal ingress bus 332 . The one or more receiver buffers, represented by receiver first-in-first-out (FIFO) memory 302 , are used to buffer frame segments before the frame is transmitted to the traffic policer 304 or other downstream processing entity.
The traffic policer 304 of the preferred embodiment is adapted execute ingress traffic policy and frame discard locally prior to transmission to the network processor 130 . In the preferred embodiment, the policer 304 employs a Three Color Marker (TCM) algorithm to identify frames for discard based upon criteria retained at or otherwise accessible by the policer 304 . Policing locally at each of the plurality or AMs 102 replaces, reduces, or augments the policing function conventionally implemented in the network processor 130 .
The traffic policer 304 , illustrated in greater detail in FIG. 4 , preferably comprises a first parser 402 , a flow search engine (FSE) 404 with ingress CAM 405 , an ingress meter module 420 , a mark generator 422 , and an ingress discard control logic 424 . An ingress frame received from a MAC 210 via the receiver FIFO 302 is inspected by the parser 402 and one or more bits or fields extracted to form an index into the ingress CAM 404 where the search is preferably conducted. In the preferred embodiment, the CAM index comprises the source port 502 , the VLAN tag state 504 indicating the presence or absence of an 802.1Q tag, and the original frame tag control information (TCI) field 506 , which are illustrated schematically in the tabular form of ingress CAM table 500 of FIG. 5 . In some embodiments, the ingress CAM index further comprises an Options field 512 to refine the search by selectively enabling or disabling one or more CAM search parameters using the following properties:
VLAN ID enable bit to selectively enable the search using the VLAN ID field of the ingress frame; TCI enable bit to selectively enable the search using the tag control information of the ingress frame; Source Port enable bit to selectively enable the search using the source port associated with the ingress frame; Trusted/Untrusted port bit, from the TCI from outer VLAN tag of ingress frame, to selectively enable the search using the priority of the ingress frame; and Ethertype enable bit to selectively enable the search using the Ethertype (VLAN protocol identifier=x8100 or other) of the ingress frame.
If a match is detected, the FSE 404 retrieves a flow index 508 that points into the flow database 406 where various flow processing parameters are retrieved. As represented schematically by the tabular form 510 of the flow database 406 illustrated in FIG. 5 , the FSE 404 retrieves from the flow database 406 one or more forms of processing information including VLAN information 514 to support VLAN tagging and bandwidth parameters to support flow control. The VLAN information 514 may include, but is not limited to, a new VLAN tag, a new VLAN ID for an existing tag, and a new TCI for an existing tag. In the preferred embodiment, the flow database 406 further includes an index into the policing database 408 pointing to one or more bandwidth parameters, e.g., TCM traffic parameters, necessary to police the ingress traffic flow.
In the preferred embodiment, the traffic policer 304 employs a TCM algorithm to selectively identify and discard out-of-prifile frames, preferably a single rate Three Color Marking (srTCM) algorithm or the two rate Three Color Marking (trTCM) algorithm. The first, srTCM, is defined in Internet Engineering Task Force (IETF) Request for Comment (RFC) 2697, while trTCM is defined in IETF RFC 2698, both of which are hereby incorporated by reference herein. Either TCM algorithm described in these standards may be used alone or in combination to augment other decision-making processes in the switching device 100 responsible for determining if packets are out-of-profile and thus when to discard packets.
Referring to FIG. 4 again, to execute the srTCM algorithm, the policer 304 includes an ingress meter module (IMM) 420 to measure how much data is flowing per given unit time, which is indicated by the flow rate result 430 transmitted to the marker generator 422 . Based on that measurement, the marker generator 422 classifies the frame into one of three categories referred to by those skilled in the art as “colors,” namely green, yellow, and red. The color associated with a frame is determined as a function of traffic parameters defined for each of the flows. The traffic parameters in srTCM include a committed information rate (CIR) and two associated burst sizes, namely a committed burst size (CBS) and an excess burst size (EBS), all of which were retrieved from the policing database 408 as a function of the particular flow.
In general, the marker generator 422 evaluates the flow in accordance with srTCM to determine which mark to apply. If the frame does not exceed the CBS, a green marker is applied to indicate that the frame should be delivered to the next downstream process after the policer 304 . A frame that is part of a flow that exceeds both the CIR and EBS is marked red and immediately discarded. If the frame exceeds the CBS but not the EBS, a yellow marker is associated with the frame to signify that the frame may be delivered as long as there are system resources or queuing resources to do so. The frame may be marked using a protocol-specific field or non-protocol marking when not supported by the protocol. Although a yellow frame may be discarded depending on the availability of system resources, it must always be dropped before a green frame is dropped. In the preferred embodiment, a discard control logic (DCL) units 424 is used downstream of marker generator 422 to inspect the marker on each frame and selectively drop the frame as needed as a function of systems resource, including congestion.
In the preferred embodiment, the CIR and EBS are implemented as bandwidth counters associated with a “Conform” bucket and an “Exceed” bucket, respectively. The maximum size of each counter is 256K bytes and is programmable by the network administrator. Each of the counters is “paid” with a programmable unit of tokens or bytes representing a quantity of bandwidth or the number of frames, for example. The tokens are “spent” by frames by deducting the length of the frame from the Conform bucket or the Exceed bucket, depending on the flow rate. In particular, the size of an inbound frame is compared to the accumulated pay in each counter. If the size is greater than the pay, the frame has “violated” the counter and needs to be marked. A frame that does not violate the Conform bucket is not marked and is enqueued into the global buffer, MAC buffer 306 . Pay equal to the length of the frame is then reduced from the Conform counter. A frame that violates the Conform bucket is marked “yellow” and then enqueued into the buffer. Pay equal to the length of the frame is then reduced from the Exceed counter. Frames that violate both the Conform bucket and the Exceed bucket are marked “red” and dropped.
At a periodic interval, the Conform bucket or the Exceed bucket are paid and the tokens replenished to a programmable maximum value. In the preferred embodiment, the two counters may be programmed with different values of pay, even though the increment is done at the same time interval. One skilled in the art will appreciate that the pay for the Conform bucket must always be less than the Exceed bucket pay, and that the Exceed bucket is paid only after the Conform bucket has maximum pay.
The Conform bucket controls the Committed Information Rate and the Exceed bucket controls the Peak Information Rate. Both the rates are programmable, have a granularity of 64 kbps and can range from 64 Kbps to 1 Gbps. The frames marked red are dropped in the MAC preprocessor 220 . The frames marked yellow are preferably carried through on the high speed serial interface 330 to the network processor 130 .
In addition to the TCM traffic parameters used to implement policing, the FSE 404 also retrieves one or more VLAN identifiers applicable to the inbound frame. In the preferred embodiment, the one or more VLAN identifiers are derived from a tag options field in the VLAN information field 514 of the table 510 of the flow database 406 . Once the applicable VLAN tag is identified, the VLAN tag is written to VLAN ID database 410 where it is made available to the VLAN push module 308 for purposes of performing 802.1Q VLAN tagging.
The policer 304 then transmits frames passed by the ingress DCL 424 to the MAC buffer 306 . The MAC buffer 306 includes a global 512 kilobyte buffer that is shared by the twelve receive MAC interfaces 210 . The 512 kilobyte buffer is split into 8192 chunks of 64 bytes. In general, the frames read from the different MAC interfaces 210 are stored into the receive buffer in their order of arrival.
In the preferred embodiment, the MAC preprocessor 200 may be implemented in an oversubscribed environment where the collective input of the MAC preprocessor 200 from the MAC interfaces 210 exceeds the capacity of the MAC processor 200 to transmit them to the network processor 130 . As such, one or more frame discard algorithms are employed to drop all incoming frame when the MAC buffer 306 is full. The discard algorithms may be employed to drop frames based upon various factors including the priority of the inbound packet as taught in U.S. patent application Ser. No. 10/068,710. The inbound frames are discarded if at least one 64 bytes chunk the MAC buffer 306 is not free.
In the preferred embodiment, the frame discard algorithms are implemented at four levels:
at the frames parser 402 level preceding the MAC buffer 306 ; at MAC buffer 306 input via a protocol CAM (not shown) and frame priority descriptors; at MAC buffer 306 write time using Weighted Early Random Discard (WRED) or FIFO thresholds, i.e. “watermarks,” that trigger frame discard at a plurality of MAC buffer 306 FIFOs, each FIFO being associated with priority for one of the twelve ports; and at MAC buffer 306 read time via a class-based, i.e. priority-based, FIFO dequeueing algorithm.
One skilled in the art will appreciate that in an oversubscribed environment, the presence of the traffic policer 304 is particularly important since it provides an intelligent way to discard the frames early and prevents out-of-profile frames from needlessly consuming the resources and memory in the MAC buffer 306 . By eliminating offending frames prior to processing and buffering, the network processor 130 is relieved of the burden of processing the frames and the chance of discarding a valid frame due to the lack of available buffer space and other resources is minimized.
As the frames are released from the MAC buffer 306 , individual frames are transmitted to the VLAN push module 308 where one or more VLAN tags are inserted into selected frames. In the preferred embodiment, the VLAN push module 308 retrieves the one or more VLAN IDs an or other VLAN information from the VLAN ID database 410 , which were previously placed there by the FSE 404 after the frame was classified during the policing operation. The new VLAN tag information may be appended to the frame in the form of a new VLAN tag, or used to replace one tag information present in an existing VLAN tag. The manner in which the tags retrieved from the VLAN ID database 410 is to be used is determined by the tag option bits from the VLAN information field 514 of table 510 . The frame check sequence (FCS) field is also modified to account for the length of the frame with the new tag.
In some alternative embodiments, the VLAN push module 308 includes a VLAN CAM adapted to identify the appropriate VLAN ID based upon a match of one or more frame fields including the source port and incoming VLAN tag, for example. The matching entry in the VLAN CAM then points to a new tag, which is then pushed onto the packet or used to replace an existing tag.
The VLAN pushing feature, which includes a VLAN stacking feature is adapted to store and utilize as many as 128 QoS rules/VLAN entries, although more are possible. In the preferred embodiment, approximately 128 VLAN entries retained at the MAC processor 210 generally represent a subset of all the QoS rules/VLANs supported by the switching device 100 . The subset of QoS rules/VLANs supported by any given MAC processor 200 represent the minimal set of QoS rules/VLANs associated with traffic on the local MAC interface 210 while excluding QoS rules not relevant to the particular MAC processor. This provides at least two advantages. First, the depth of the CAM necessary to search for the applicable VLAN is smaller and, second, the local VLAN processing relieves the network processor of the responsibility of performing VLAN tagging and stacking.
From the VLAN push module 308 , frames are passed to an ingress rate buffer 312 responsible for transmitting the frames at a relatively uniform rate to the high speed serial (HSS) interface 316 via an ingress data bus transmitter 314 . The high speed serial (HSS) interface 316 operably couples the MAC preprocessor 220 to the network processor 130 by means a packet streaming bus, which is well known to those skilled in the art. The packet streaming bus may also operatively couple the network processor 130 to each of the plurality of MAC processors 200 .
In addition to transmitting ingress traffic, each of the plurality of MAC processors 200 also receive egress traffic from the network processor 130 . Egress traffic destined for a local PHY interface 240 port is received by the MAC postprocessor 230 at the egress bus receiver 320 via the HSS interface 330 . The egress frames are temporarily buffered at the egress rate buffer 322 and subsequently transmitted at a relatively uniform rate to the VLAN pop module 326 .
In some embodiments, the rate buffer 322 further includes a traffic shaper 324 adapted to perform bandwidth-based flow control for the egress traffic received by the MAC processor 200 . The traffic shaper 324 in the preferred embodiment regulates the MAC postprocessor 230 output bandwidth using a single token bucket algorithm in conjunction with one or more buckets, each bucket being associated with a flow class. Tokens allotted to each bucket, tracked using a “conform counter,” represent the capacity for each flow class. Each time a frame is transmitted from the rate buffer 322 , a number of tokens representing the length of the frame is deducted from the associated conform counter. If there are not enough tokens to transmit the frame, transmission of the frame from the rate buffer is suspended until the tokens are subsequently replenished. Although the shaper 324 generally does not discard frames, suspension of the bucket for an extended period of time may result in the switch fabric (not shown) backing up and or the dropping of frames at an ingress switching device.
Frames associated with a flow class are transmitted once again after the tokens are replenished. In the preferred embodiment, the conform counters are paid a maximum number of tokens at a regular time interval, programmably determined by the network administrator. In the preferred embodiment, shaping may be based on port, VLAN, and priority, or any combination thereof.
The VLAN pop module 326 is adapted to remove an existing tag on an egress frame, or to replace VLAN tag information in an existing tag or a tag previously inserted at the VLAN push module 308 of the ingress switching device. The VLAN pop module 326 of the preferred embodiment, illustrated in FIG. 6 , comprises a second parser 602 for extracting one or more bits or fields from the egress frame and an egress flow search engine 604 for generating a key into an egress CAM 605 which, if matched, yields a pointer to the VLAN identifier database 608 . Included in the VLAN identifier database 608 are the VLAN association rules embodied in option bits providing instructions remove or replace one or more existing VLAN tags, if applicable. The VLAN tag processing instructions are conveyed to the framer 610 responsible for altering the frame prior to transmission to the appropriate MAC interface 210 via the egress bus 334 . If applicable, a new CRC field is appended to the frame before it is sent out on the network.
The MAC postprocessor 230 of the preferred embodiment further includes a statistics acquisition module (SAM) 350 for compiling flow statistics from each of the MAC interfaces 210 . In the preferred embodiment, statistics are collected on a per-port basis and or per-VLAN basis. As they are compiled, the statistics are transmitted by the SAM 350 to a central management entity present in the management module 150 or another location accessible to each of the one or more switching devices 100 . If the SAM 350 is enabled with a simple network management (SNMP) client, the central management entity may periodically download the statistics using SNMP messages conveyed via the command and control interface 340 .
The statistics collected in the preferred embodiment include the total set of Remote Monitoring (RMON) and Managed Information Base (MIB)-II statistic from each of the plurality of MACs 210 via the first statistics channel 336 . RMON is set forth in a plurality of Request For Comment (RFC) known to those skilled in the art, while MIB-II is set forth in RFC 1213 entitled, “Management Information Base for Network Management of TCP/IP-based internets.” In the preferred embodiment, SAM 350 further collects statistics necessary to implement QoS features such as VLAN statistics and statistics relevant to Switch Monitoring (SMON) conformance, the SMON requirements being set forth in Internet Engineering Task Force (IETF) Request For Comment (RFC) 2613, entitled “Remote Network Monitoring MIB Extensions for Switched Networks,” hereby incorporated by reference herein.
The VLAN statistics are preferably collected on a per-VLAN entry basis for the ingress stream by way of the ingress FSE 404 and egress stream by way of egress FSE 604 , as illustrated by ingress statistics channel 338 and egress statistics channel 339 , respectively. With respect to the ingress traffic, the SAM 350 collects the following statistics, per VLAN entry supported by the MAC preprocessor 220 :
Number of bytes enqueued at the MAC buffer 306 ; Number of packets enqueued at the MAC buffer 306 ; Number of bytes discarded bytes by the traffic policer 304 ; Number of packets discarded by the traffic policer 304 ; Number of non-unicast bytes enqueued at the MAC buffer 306 ; Number of non-unicast packets enqueued at the MAC buffer 306 ; Number of non-unicast bytes discarded by the traffic policer 304 ; and Number of non-unicast packets discarded by the traffic policer 304 .
With respect to the egress traffic, the SAM 350 preferably collects and compiles statistics per-port and per-VLAN entry. The statistics acquired are subdivided into the number of dequeued bytes and the number of dequeued packets, for example. If the frame includes a plurality of VLAN tags, the statistics are accumulated on the outer tag.
Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention.
Therefore, the invention has been disclosed by way of example and not limitation, and reference should be made to the following claims to determine the scope of the present invention.
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The present invention features a data link layer processor for performing VLAN tagging operations, policing, shaping, and statistics acquisition integrally with one or more media access controllers (MACs). When a plurality of data link layer processors are operated in parallel in a switching device, the computational burden carried by the route engine is significantly reduced. Moreover, the data link layer processor in its several embodiments may be used to introduce various forms of pre-processing and post-processing into network switching systems that employ route engines that do not posses such functionality.
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RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/372,658 filed Feb. 17, 2009 entitled Restraint System, which claims priority to U.S. Provisional Application Ser. No. 61/028,753 filed Feb. 14, 2008 entitled Crew Restrain System, both of which are hereby incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] Vehicles, such as aircraft, often include restraint systems to prevent occupants from unwanted movement and injury. Typically, these restraint systems restrain the occupant from movement by releasably strapping the occupant to a chair or similar vehicle furniture.
[0003] However, some vehicles, such as helicopters or air cargo delivery planes may require an occupant to move about the interior of the vehicle. Intentional or unintentional vehicle motion such as turbulence or banking into a turn can cause an occupant to lose their balance or be thrown about the vehicle's interior. In some open vehicles such as rescue helicopters and military cargo planes, the occupant is in further danger of being thrown from the vehicle.
[0004] Therefore, what is needed is an occupant restraint system that allows an occupant to move about the interior of a vehicle, yet restrains them from unwanted movement and other dangers.
SUMMARY OF THE INVENTION
[0005] In a preferred embodiment, a restraint system is described for restraining a standing occupant in a vehicle such as a plane or helicopter. The restraint system includes a webbing strap that winds and unwinds from a spool assembly. The spool assembly includes a trigger assembly that locks a spool from rotation, a manual release assembly for manually releasing the trigger assembly and lock, and an adjustable payout assembly that determines the maximum length that the webbing strap can be pulled out before stopping (i.e., the number of rotations of the spool). The trigger assembly can trigger the lock assembly from one or more sensors. Further, the trigger assembly can be arranged to automatically unlock after a triggering event, manually unlocked after a triggering event or a combination of the two for different sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which
[0007] FIG. 1 illustrates a perspective view of a restraint system attached to an occupant within a vehicle according to a preferred embodiment;
[0008] FIG. 2 illustrates a magnified perspective view of the restraint system and occupant of FIG. 1 ;
[0009] FIG. 3 illustrates a perspective view of a spool assembly of FIG. 1 ;
[0010] FIG. 4 illustrates a perspective view of the ratchet and pawl assembly according to a preferred embodiment;
[0011] FIG. 5 illustrates a perspective view of only the ratchet and pawl assembly of FIG. 4 .
[0012] FIG. 6 illustrates a disassembled perspective view of a trigger assembly and manual release assembly according to a preferred embodiment;
[0013] FIG. 7 illustrates a perspective view of the trigger assembly and manual release assembly of FIG. 6 ;
[0014] FIG. 8 illustrates a magnified perspective view of the trigger assembly of FIG. 7 ;
[0015] FIG. 9 illustrates a perspective view of an adjustable payout assembly according to a preferred embodiment;
[0016] FIG. 10 illustrates an exploded cross sectional view of the adjustable payout assembly of FIG. 9 ;
[0017] FIG. 11 illustrates a perspective view of an dual trigger assembly according to a preferred embodiment;
[0018] FIG. 12 illustrates a perspective view of the dual trigger assembly of FIG. 10 ; and
[0019] FIG. 13 illustrates an exploded perspective view of the dual trigger assembly of FIG. 11 .
DESCRIPTION OF EMBODIMENTS
[0020] Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.
[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0022] FIGS. 1 and 2 illustrate a preferred embodiment of an occupant restraint system 100 for a vehicle, such as a plane or helicopter. Generally, the occupant restraint system 100 includes a spool assembly 106 and a webbing strap 108 that is selectively wound and unwound from the spool assembly 106 .
[0023] Preferably the spool assembly is pivotally mounted to the side or ceiling of a vehicle's interior 102 by pivot bracket 112 . This arrangement allows the spool assembly 106 to pivot in any direction as the occupant 110 moves through the vehicle's interior 102 .
[0024] The webbing strap 108 is preferably latched to a harness 110 worn by an occupant. As the occupant 110 moves within the vehicle's interior 102 , the spool assembly 106 releases and retracts the webbing strap 108 as needed. However, during sudden or forceful movement, the spool assembly 106 locks, preventing further extension of the webbing strap 108 and thereby preventing excessive movement of the occupant 110 .
[0025] In addition to or in place of the pivot bracket, the spool assembly can be connected to a trolley device that runs along a track as seen in U.S. Pat. No. 7,275,710, the contents of which are hereby incorporated by reference. Hence, the user can walk along an extended length of a vehicle (e.g., the length of an airplane) while attached to the restrain system.
[0026] FIG. 3 illustrates a magnified view of the spool assembly 106 , including a framework 126 , outer coverings 114 and 116 , a webbing strap payout adjustment mechanism 118 and a manual lock reset handle. When the spool assembly 106 is caused to lock further spooling of the webbing strap 108 (e.g., due to rapid webbing payout velocity), the user can release the spool assembly 106 by pulling on the spring-biased manual reset handle 122 .
[0027] FIGS. 4-8 illustrate various views of the trigger mechanism of the spool assembly 106 . Turning first to the ratchet and pawl engagement assembly (seen best in FIGS. 4 and 5 ), this assembly prevents the spool 150 from rotating during a triggering event (e.g., a crash or sudden acceleration) by way of a first pawl member 142 that selectively engages a first spool ratchet 150 and a second pawl member 156 that selectively engages a second spool ratchet 154 . The first pawl member 142 is biased towards the first spool ratchet 150 by pawl spring 140 . The second pawl member 156 is linked to the first pawl member 142 via a connecting shaft 155 , allowing the second pawl member 156 to move in unison with the first pawl member 142 .
[0028] During normal operation, a trigger mechanism 121 (seen best in FIGS. 6 and 7 ) maintains a pawl pin 142 A and therefore the first pawl member 142 and second pawl member 156 in a raised position, away from the jagged surfaces of ratchets 150 and 154 . When the trigger mechanism 121 “triggers”, it releases any resistance on the pawl pin 142 A and thereby allows the pawls 142 and 156 to be biased against the ratchets 150 and 154 . This released pawl position stops the movement of the spool 152 .
[0029] The trigger mechanism 121 includes a rotationally mounted trigger plate 120 having a plurality of radial engagement members 120 B and a plurality of perpendicular engagement members 120 A. The radial engagement members have various uses in the trigger mechanism 121 . For example, a first radial engagement member is in contact with a fixed spring 124 which biases the trigger plate 120 for movement in a counter clockwise rotational direction. In another example, a second radial engagement member 120 B contacts and maintains the unlocked spool position by pressing against the pawl pin 142 A. In yet another example, a third radial engagement member 120 B contacts lever 136 of an acceleration sensor 128 .
[0030] The acceleration sensor 128 includes a spherical weight 130 that is freely positioned over cup 132 . Preferably, an additional enclosure is provided around the weight 130 to prevent it from completely moving off of cup 132 . A lower post portion of the cup 132 contacts a lever pin 136 A, biasing the lever 136 downward against radial engagement member 120 B of the trigger plate 120 . The spring 134 preferably reduces the amount of weight that weight 130 places on the pin 136 A to allow for greater sensitivity of the acceleration sensor 128 . Additionally, the interior surface of the cup 132 includes conical or ramped surfaces for sideways or rolling acceleration.
[0031] When the vehicle suddenly accelerates (e.g., drops downward and abruptly stops from a crash), the weight 130 increases pressure on the pin 136 A (e.g., from the sudden stop in acceleration) and thereby the lever 136 . As the lever 136 moves downward against the radial engagement member 120 B, the trigger plate 120 rotates in a clockwise direction, allowing the pawls 142 and 156 to move downward and stop the ratchets 150 and 154 from rotating. When the vehicle banks or rolls hard, the weight 130 will move to the side of the cup 132 against the conical or ramped surface. Since the previously described weight enclosure prevents the weight 130 from moving upwards, away from the cup 132 , the cup 132 and its pin are pushed downward, triggering the trigger plate 120 as previously described.
[0032] The trigger mechanism 121 can also be activated when the spool 152 is rotated too quickly as opposed to rotating with too much acceleration. Prior restraint trigger mechanisms tend to trigger a locking mechanism at different angular speeds when pulling out the webbing strap. For example, pulling a webbing strap at a constant linear speed away from a restraint device can result in the spool moving more slowly initially (the spool is larger in diameter when fully wound with the webbing) and more quickly after the webbing has been pulled out a distance (the spool is smaller in diameter when less webbing is on the spool). The trigger mechanism 121 reduces this behavior by with two opposed, biased plates 144 and 146 .
[0033] More specifically, the first velocity plate 144 and the second velocity plate 146 are positioned against the trigger plate 120 and rotate with the spool 152 . Both velocity plates 144 and 146 include a mounting groove that allows the plates 144 and 146 to be captured for rotational movement and slide away from the axial. Two springs 146 bias the plates 144 and 146 against each other during normal operation. When these plates 144 and 146 rotate too quickly, the rotational velocity pulls the plates 144 and 146 away from each other, against the bias of the springs 138 . As the plates 144 and 146 move away from each other, their engagement members 144 A and 146 A contact the perpendicular engagement members 120 A, causing the trigger plate 120 to rotate and trigger the pawl 142 . It should be understood that changing the tension or spring constant of springs 138 can adjust the threshold at which the plates 144 and 146 engage the perpendicular engagement members 120 A.
[0034] Preferably, the relative spring rates or spring constants of the previously described triggering mechanisms (i.e., springs 124 , 134 and 140 ) are such that once the triggering mechanism 121 has been triggered it will not disengage until manually released by the user. As seen best in FIG. 7 , manual release of the triggering mechanism 121 is controlled by pulling back the manual reset handle 122 . When triggered, the trigger plate 120 has rotated in a clockwise direction, bringing one of the radial engagement members 120 B closer to or in contact with the pin 122 A of the handle 122 . The user pulls back on the handle 122 , against the bias of spring 123 to press the pin 122 A against the radial engagement member 120 B, thereby rotating the trigger plate 120 . When the handle 122 has been pulled back far enough, a radial engagement member 120 B near the pawl 142 lifts pawl pin 142 A up to unlock the spool 152 . Hence, the spool assembly 106 can again extend and retract the webbing strap 108 as needed by the occupant.
[0035] FIGS. 9 and 10 illustrate the previously mentioned adjustable payout assembly 160 that stops the webbing strap 108 from unwinding from the spool 152 . More specifically, the payout assembly 160 triggers a payout pawl 174 that engages the ratchet 154 (seen in FIG. 4 ) or alternately a third ratchet.
[0036] The payout assembly 160 is actuated by rotation of a lead screw 162 that is keyed or captured by the spool 152 . In this respect, the lead screw 162 is free to move along an axis of the spool 152 while also rotating with the spool 152 . A compression spring 178 is coupled to an interior of the lead screw 162 to preload the screw 162 away from the spool 152 . A trigger nut 166 is threaded over the lead screw 162 and captured by a keyway 182 A of the housing 182 , allowing the trigger nut 166 to move axially within the keyway 182 A.
[0037] As the trigger nut 166 moves axially outward, away from the spool 152 , a pin 180 contacts and bottoms out on one of the plurality of indentations 164 . Since the trigger nut 166 can no longer move axially away from the spool 154 , the lead screw 162 unscrews from the trigger nut 166 and thereby move toward the spool 154 . As the end of the lead screw 162 approaches the trigger plate 172 , a trigger post 168 on the lead screw 162 contacts and engages one of the locking dogs 170 which are raised from the surface of the trigger plate 172 .
[0038] Normally, the spring 176 biases the trigger plate 172 in a clockwise direction so that the trigger member 172 A lifts up the payout pawl pin 174 A and therefore the payout pawl 174 , allowing the spool 152 to rotate freely. However, when the trigger plate 172 rotates in a counterclockwise direction, driven by the rotation of the lead screw 162 , the trigger member 172 A moves away from the payout pawl pin 174 A, allowing the payout pawl 174 to drop on to the ratchet 154 and stop further movement of the spool 152 .
[0039] When pressure from the lead screw 162 is removed from the trigger plate 172 , the spring 174 urges the trigger plate 172 and the trigger member 172 A back in a clockwise position so as to lift the payout pawl pin 174 A and thus the payout pawl 174 in a raised position, away from the ratchet 154 . In this respect, the spool 152 is free to rotate again (to wind up the webbing strap 108 .
[0040] The point at which the payout assembly 160 locks can be adjusted by a user by rotating the adjustment knob 118 . The previously discussed pin 180 is eccentrically positioned inside the adjustment knob 118 . Therefore, rotation of the knob 118 aligns the pin 180 with different indentations 164 on the trigger nut 166 . Each of the indentations 164 are located at different depths from the surface of the trigger nut 166 and therefore allow the trigger nut 166 to move to various distances from the trigger plate 172 . Hence, the payout assembly 160 will lock at various, user adjustable positions.
[0041] FIGS. 11-13 illustrate an alternate preferred embodiment of a trigger assembly 190 that engages a first trigger mechanism that automatically releases when tension is released and a second trigger mechanism that must be manually released. In this respect, the spool 152 can be locked by pulling on the webbing strap 108 , and then unlocked by releasing tension on the webbing strap 108 . However, if the pulling exceeds a certain threshold, the spool 152 must be manually released.
[0042] In addition to the previously described pawl 142 , an automatic reset pawl 198 is pivotally mounted via pivot 198 B underneath ratchet 150 . A pawl pin 198 A is connected to a side of the pawl 198 and extends through an aperture in the framework 126 .
[0043] As best seen in FIG. 13 , trigger assembly 190 includes an automatic-unlock trigger plate 192 that is engaged by velocity plates 144 and 146 as previously described in this specification. The automatic-unlock trigger plate 192 is rotationally biased in a counter clockwise direction via a spring (not shown) similarly to the previously described plate 120 . This rotational bias urges radial engagement member 192 B toward the pawl pin 198 A, preventing the pawl 198 from contacting the ratchet 150 .
[0044] When the velocity plates 144 and 146 engage the axial engagement members 192 A, the plate 192 is rotated in a clockwise direction, causing member 192 B to release pressure on pawl pin 198 A and thereby causing the pawl 198 to engage the ratchet 150 . When pressure is released on the webbing strap 108 , the velocity plates 144 and 146 release their engagement of the plate 192 , allowing the spring to rotate the plate 192 back in a counter-clockwise direction to reengage the pawl pin 198 A and thereby release the pawl 198 from the ratchet 150 .
[0045] As previously discussed, if the force and or acceleration of the webbing strap exceeds a threshold, a manually released trigger mechanism is activated. This threshold is created, in part, by a resistance spring 195 in a recessed spring well 194 B. The resistance spring 195 is engaged with the spring well 194 B and a ramp (not shown) on the back of plate 192 . The resistance spring 195 compresses when the plate 192 is rotated with a relatively slow or low acceleration. However, faster rotational speed or acceleration overcomes the compression of the spring 195 , causing the mating plate 194 to rotate in a clockwise direction. A pin on radial engagement member 194 C contacts and pushes radial engagement member 196 B of the manual unlock trigger plate 196 , thereby causing trigger plate 196 to rotate in a clockwise direction. This rotation releases pressure of radial engagement member 196 A on the pawl pin 142 A, causing the pawl 142 to lower onto the ratchet 150 and lock the spool 152 .
[0046] Preferably, the trigger plate 196 is spring biased in a counterclockwise position, but with a force that will not overcome rotation of the trigger plate in the locked position. In other words, once the trigger plate 196 locks, it remains in its locked, rotated position.
[0047] While not shown in FIGS. 11-13 , a manual release mechanism can be used to release the trigger plate 196 , thereby rotating the plate 196 back to its original position and lifting the pawl 142 . For example, the manual release mechanism shown in FIGS. 5-8 (i.e., the handle 122 , spring 123 and pin 122 A) can be used to release the trigger plate 196 .
[0048] Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
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In a preferred embodiment, a restraint system is described for restraining a standing occupant in a vehicle such as a plane or helicopter. The restraint system includes a webbing strap that winds and unwinds from a spool assembly. The spool assembly includes a trigger assembly that locks a spool from rotation, a manual release assembly for manually releasing the trigger assembly and lock, and an adjustable payout assembly that determines the maximum length that the webbing strap can be pulled out before stopping (i.e., the number of rotations of the spool). The trigger assembly can trigger the lock assembly from one or more sensors. Further, the trigger assembly can be arranged to automatically unlock after a triggering event, manually unlocked after a triggering event or a combination of the two for different sensors.
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FIELD OF THE INVENTION
[0001] This invention relates to a method of operation for a fuel cell system. More particularly, the invention is directed to managing power increases in a hydrogen fuel cell system using an air mass flow feedback delay.
BACKGROUND OF THE INVENTION
[0002] In most modern fuel cell systems, a compressor provides compressed air to the fuel cell stack. Having sufficient air for the fuel cell reaction is extremely important and is characterized as “Cathode Stoichiometry” wherein a higher value (e.g. 5) is typically needed at low current densities and a lower value (e.g. 1.8) is typical at high current densities. In such systems it is necessary to have a means for sensing the air mass flow rate leaving the compressor and entering the fuel cell stack, such as an air mass flow sensor.
[0003] A control system will typically take this flow information and change the speed of the compressor along with the position of a back pressure valve to achieve a desired air mass flow and gas pressure entering the fuel cell stack. The desired air mass flow and gas pressure are generally calculated using known factors such as the fuel cell stack current, number of cells in the fuel cell stack, and the desired cathode stoichiometry at that stack current.
[0004] In such fuel cell systems the control system typically allows an external circuit to draw current out of the fuel cell system immediately upon detection of the desired air mass flow rate by the air mass flow sensor. The volume and distance between the location where the air mass flow sensor is taking the measurement and the location where the air is required at the reaction site of the fuel cell stack are not taken into account. Therefore, the current is drawn out of the fuel cell stack before the desired air mass flow is actually present at the reaction site. The lack of air at the reaction site can cause the cathode stoichiometry at the reaction site to drop enormously, and lead to significant voltage drops in cells that are sensitive to low cathode stoichiometries. The lowered cell voltages can at least cause the power management circuit to limit power output and could reverse (i.e. negative voltage) causing massive degradation. The lack of air is particularly harmful on current draw up-transients. The prior art systems do not take into account the distance and volume between where the air mass flow meter is taking the measurement and where the air-H 2 reaction actually takes place.
[0005] It would be desirable to develop a method of managing fuel cell power increases which would account for the volume and distance between the air mass flow sensor and the reaction site insuring the required air mass flow rate had reached the reaction site before the current is drawn from the fuel cell stack.
SUMMARY OF THE INVENTION
[0006] According to the present invention, a method of managing fuel cell power increases which would account for the volume and distance between the air mass flow sensor and the reaction site insuring the required air mass flow rate had reached the reaction site before the current is drawn from the fuel cell stack, has surprisingly been discovered. This method ensures that throughout an up-transient, the cathode stoichiometric requirement is always met at the site of the reaction. By ensuring this, stack stability is improved by preventing any one cell that is cathode stoichiometrically sensitive from losing voltage as a result of not having sufficient air. A secondary, but equally important, effect is the prevention of cathode starvation that leads to accelerated voltage degradation.
[0007] In one embodiment, the method for managing fuel cell power increases using air flow feedback delay comprises the steps of determining gas flow effecting characteristics of the fuel cell system between the compressor and the cathode outlet; determining an air mass flow rate between the compressor and the cathode outlet; determining a gas pressure of the fuel cell system between the compressor and the cathode outlet; calculating the air flow feedback delay as a function of said gas flow effecting characteristics, said air mass flow rate, and said gas pressure; and delaying the external circuit from drawing current out of the fuel cell stack by the magnitude of the air flow feedback delay.
DESCRIPTION OF THE DRAWINGS
[0008] The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
[0009] FIG. 1 is a schematic diagram of a fuel cell system according to an embodiment of the invention; and
[0010] FIG. 2 is a graph with time on the x-axis and showing actual air mass flow on a cathode side of the fuel cell system illustrated in FIG. 1 compared to a required air mass flow on the cathode side based on a current drawn by an external circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
[0012] Referring now to FIG. 1 , a basic layout of a fuel cell system with associated components is shown; in practice many variants are possible. A schematic representation of a fuel cell stack 10 integrated into a fuel cell system and consisting of a plurality of individual fuel cells which are connected electrically in series and/or in parallel is shown. The anode sides of all individual fuel cells of the fuel cell stack 10 are connected together in a manner commonly known in the art with the resulting anode side of the stack being designated with the reference numeral 12 . In similar manner the cathode sides of all fuel cells of the stack are connected together in a manner commonly known in the art with the resulting anode side of the stack being designated with the reference numeral 14 . The operations of various types of fuel cell systems are commonly known in the art; one embodiment can be found in commonly owned U.S. Pat. No. 6,849,352. Therefore, only the operation of a fuel cell system as pertinent to this invention will be explained in the description.
[0013] In the exemplary embodiment described herein, the fuel cell system includes a control system 16 . The control system 16 is connected via a line 18 to a motor 20 . The motor 20 is coupled with a compressor 22 . The compressor 22 is in fluid communication with a cathode inlet 24 of the fuel cell stack 10 via an air supply line 26 . The line 26 is a sealed passageway having known gas flow effecting characteristics such as static volume, distance, internal roughness, laminar and/or turbulent flow effects.
[0014] An air mass flow sensor 30 is disposed in the line 26 between the compressor 22 and a humidifier 28 . The air mass flow sensor 30 is linked to the control system 16 via a line 32 . The air mass flow sensor 30 is an electromechanical device having known gas flow effecting characteristics such as roughness, laminar and/or turbulent flow effects.
[0015] A temperature sensor 31 is connected to the line 26 between the compressor 22 and the cathode outlet 48 of the fuel cell stack 10 . The temperature sensor 31 is linked to the control system 16 via a line 52 . The temperature sensor 31 can be an electrical or electromechanical device having a known gas flow effecting characteristics such as roughness, laminar and/or turbulent flow effects.
[0016] The humidifier 28 is disposed in the line 26 between the air mass flow sensor 30 and the cathode inlet 24 . The humidifier unit 28 is composed of a plurality of individual components all having known gas flow effecting characteristics such as roughness, laminar and/or turbulent flow effects.
[0017] Additionally, other components may be disposed in or connected to the line 26 between the air mass flow sensor 30 and the cathode inlet 24 in other embodiments.
[0018] The cathode side 14 of the fuel cell stack 10 comprises a plurality of cathodes of individual fuel cells connected in a manner commonly known in the art. Each individual fuel cell has a plurality of channels between the cathode inlet 24 and the cathode outlet 48 all having known gas flow effecting characteristics such as static volume, distance, internal roughness, laminar and/or turbulent flow effects.
[0019] A back pressure valve 29 is connected to the cathode outlet 48 of the fuel cell stack. It may also be desirable for the back pressure valve 29 to be connected to the line 26 between the compressor 22 and cathode side 14 of the fuel cell stack 10 . The back pressure valve 29 is linked to the control system 16 via a line 54 . The back pressure valve 29 is an electromechanical device having known gas flow effecting characteristics such as roughness, laminar and/or turbulent flow effects.
[0020] A gas pressure sensor 33 is connected to the cathode outlet 48 of the fuel cell stack 10 . It may also be desirable for the gas pressure sensor 33 to be connected to the line 26 between the compressor 22 and cathode side 14 of the fuel cell stack 10 . The gas pressure sensor 33 is linked to the control system 16 via a line 50 . The gas pressure sensor 30 is an electromechanical device having known gas flow effecting characteristics such as roughness, laminar and/or turbulent flow effects.
[0021] An external circuit 34 is electrically linked to the cathode side 14 of the fuel cell stack 10 via a line 36 and electrically linked to the anode side 12 of the fuel cell stack 10 via a line 38 . The external circuit 34 is linked to the control system 16 via a line 40 .
[0022] In operation, air is pulled in via a line 42 and compressed by the compressor 22 driven by the motor 20 and is supplied via the line 26 through the cathode inlet 24 of the fuel cell stack 10 to the cathode outlet 48 . The amount of time required for the air to reach the cathode inlet 24 of the fuel cell stack 10 is influenced by the gas flow effecting characteristics of the line 26 such as the static volume, distance, internal roughness, laminar and/or turbulent flow effects of the line 26 . The amount of time required for the air to reach the cathode inlet 24 of the fuel cell stack 20 is also further influenced by the gas flow effecting characteristics of the components disposed in and connected to the line 26 such as roughness, laminar and/or turbulent flow effects of including but not limited to the air mass flow sensor 30 , the gas temperature sensor 31 , and the humidifier 28 . The time required for the air to travel from the cathode inlet 24 to the cathode outlet 48 is influenced by gas flow effecting characteristics of the static volume, distance, internal roughness, laminar and/or turbulent flow effects of the plurality of channels on the cathode side 14 of the fuel cell stack 10 .
[0023] The air mass flow can be measured by the air mass flow sensor 30 and communicated to the control system 16 via the line 32 .
[0024] The gas temperature can be measured by the gas temperature sensor 31 and communicated to the control system 16 via the line 52 .
[0025] The gas pressure is measured by the gas pressure sensor 33 and communicated to the control system 16 via the line 50 .
[0026] The control system 16 can influence the speed of rotation of the air compressor 22 by controlling the motor 20 via the line 18 and thus the air mass flow delivered by the air compressor 22 . The control system can further influence the position of the back pressure valve 29 via the line 54 and thus the gas pressure in the cathode side 14 of the fuel cell system. By influencing the air mass flow delivered and the gas pressure on the cathode side 14 of the fuel cell system the control system 16 can achieve a desired air mass flow and pressure in the cathode side 14 of the fuel cell system. The desired air mass flow and pressure in the cathode side 14 of the fuel cell system are calculated using known variables such as the stack current, number of cells, and desired cathode stoichiometry at that stack current.
[0027] Hydrogen gas is delivered to the anode side 12 in a manner commonly known in the art via a line 44 . A reaction known per se in the art occurs between the air in the cathode side 14 and the hydrogen in the anode side 12 of the fuel cell stack 10 that releases electrons which can be drawn by the external circuit 34 via the line 38 .
[0028] The pressure and air mass flow rate of the gas into the cathode side 14 of the fuel cell stack 10 influence the rate of the electron releasing reaction between the air in the cathode side 14 and the hydrogen in the anode side 12 thus influencing the voltage and current available to be drawn from the fuel cell stack 10 by the external circuit 34 .
[0029] The control system 16 will calculate a feedback delay 46 ( FIG. 2 ), taking air mass flow feedback received via the line 32 , gas pressure feedback received via the line 50 , gas temperature feedback received via the line 52 , and the known influence of the static volume and distance of the line 26 on air flow, and the known influence on air flow of the static volume and distance of the plurality of channels between the cathode inlet 24 and the cathode outlet 48 of the fuel cell stack 10 .
[0030] Furthermore, the control system may use supplemental factors in calculating the feedback delay. Additional gas flow effecting characteristics of the line 26 and the plurality of channels between the cathode inlet 24 and the cathode outlet 48 such as the internal roughness, geometry, laminar and/or turbulent flow effects on the gas can be used as factors in calculating the feedback delay. The gas flow effecting characteristics of components disposed in or connected to the line 26 such as the air mass flow sensor, gas temperature sensor, back pressure valve, and humidifier may also be used as inputs in calculating the feedback delay 46 .
[0031] The feedback delay 46 is an amount of time that the control system 16 will delay the external circuit 34 from drawing current out of the fuel cell stack 10 . The control system 16 can influence the external circuit 34 via the line 40 to draw current from the fuel cell stack 10 when a desired air mass flow rate is achieved after the feedback delay 46 . The feedback delay calculation is in real time so that the control system instantaneously adjusts the current draw.
[0032] The feedback delay 46 is implemented in order to compensate for the distance and volume between the air mass flow sensor 30 and the cathode outlet 48 of the fuel cell stack 10 and to ensure that the desired air mass flow is actually present at the cathode outlet 48 of the fuel cell stack 10 when the external circuit 34 draws current from the fuel cell stack 10 . The feedback delay 46 may also compensate for the air flow restricting characteristics of the components disposed in or connected to the line 26 .
[0033] Without departing from the scope of this invention the control system 16 also, or additionally can use the gas pressure signal on the line 50 and the gas temperature signal on the line 52 as inputs in determining the delay 46 . The control system 16 can further factor laminar and/or turbulent flow effects on the air mass and take into account the internal roughness of each component between the compressor 22 and the cathode outlet 48 without departing from the scope of this invention.
[0034] FIG. 2 illustrates the actual air mass flow at the cathode side 14 of the fuel cell stack 10 in comparison to the required air mass flow at the cathode side 14 based on the stack current actually being drawn by the external circuit 34 . A value in amperes (y-axis) of the stack current being drawn during the up-transient versus time (x-axis) is indicated by a line 56 . A value of the actual air flow at the reaction site without delay (y-axis) versus time is indicated by a line 58 . A value of the required air mass flow at the reaction site based upon the stack current (y-axis) is indicated by a line 60 . The delay 46 will ensure sufficient air at the cathode side 14 of the fuel cell stack 10 .
[0035] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, make various changes and modifications to the invention to adapt it to various usages and conditions.
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A method for managing fuel cell power increases in a fuel cell system using an air flow feedback delay. The method comprises the steps of determining a required air mass flow rate at a predetermined point in the fuel cell system, determining an actual air mass flow at a predetermined point in the fuel cell system, calculating an air flow feedback delay as a function of the required air mass flow rate and the actual air mass flow, and delaying an external circuit from increasing current draw from the fuel cell stack by the magnitude of the air flow feedback delay.
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RELATED APPLICATION
[0001] The present application is a continuation-in-part of, and hereby claims priority under 35 U.S.C. §120 to, a co-pending non-provisional application by William C. Athas, entitled, “Method and Apparatus for Increasing the Operating Frequency of an Electronic Circuit,” having Ser. No. 09/991,092, and filing date of 16 Nov. 2001 (Attorney Docket No. APL-P2682).
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the design of electronic circuits. More specifically, the present invention relates to a method and apparatus for selectively increasing the operating frequency of an electronic circuit.
[0004] 2. Related Art
[0005] As computer system performance continues to increase at an exponential rate, the circuitry within the computer systems is forced to keep pace with ever-faster frequencies. These faster frequencies mean that the circuitry switches more often, which causes the circuit to consume more power. As the circuitry consumes more power, it produces more heat.
[0006] This heat must somehow be removed so that the temperature within the computer circuits does not exceed a maximum operating temperature. To this end, computer systems typically include a number of heat-dissipating components, such as heat sinks, cooling fans and heat pipes to dissipate thermal energy.
[0007] Unfortunately, providing these heat-dissipating components within a computer system can present a number of problems. First, these heat-dissipating components can significantly increase the volume and weight of a computer system, which is especially a problem for portable computer systems in which volume and weight must be minimized. Second, providing these heat-dissipating components can significantly increase the manufacturing cost of a computer system. Third, providing these heat-dissipating components can reduce reliability of a computer system, because components such as cooling fans, can fail. Furthermore, some of these components such as cooling fans, consume extra power and can thereby decrease battery life in a portable computer system.
[0008] In order to reduce the power consumption, many portable computer systems enter a power conservation mode whenever the computer system is not busy. During this power conservation mode, the computer system operates at reduced frequency and voltage levels to minimize the amount of power consumed by the computer system, and to thereby increase battery life. When the computer system becomes busy again, the frequency is increased to a maximum sustainable frequency. For many portable computer systems, this maximum sustainable frequency is determined by the capacity of the computer system to dissipate heat.
[0009] Note that this maximum sustainable frequency is determined by assuming that the computer system will operate continuously at this frequency. Most computer applications, however, do not perform computational work continuously. In fact, most applications tend to perform computational work for short, concentrated bursts between long idle periods when the computer system is waiting for user input. Hence, the maximum sustainable operating frequency is typically too conservative because it is based on the worst-case assumption that an application performs computational work continuously.
[0010] What is needed is a method and an apparatus for selectively increasing the operating frequency of a computer system.
SUMMARY
[0011] One embodiment of the present invention provides a system that facilitates selectively increasing the operating speed of an electronic circuit, such as a computer system, in order to balance power consumption with performance. The system begins in a low-power state with the frequency and voltage of the electronic circuit set to low levels. Upon recognizing the need for performance beyond the low power level, the electronic circuit enters the first-intermediate power state. In this first-intermediate power state, the frequency and voltage are set to first-intermediate levels. Upon recognizing the need for performance beyond the first-intermediate power state, the electronic circuit enters a maximum-sustainable power state. In this power state, the frequency and voltage are set to maximum sustainable levels. Upon recognizing the need for performance beyond the maximum-sustainable power state, the electronic circuit temporarily enters a boosted power state beyond the maximum-sustainable power state. In this boosted power state, the frequency and voltages are set to levels beyond the maximum sustainable levels.
[0012] In a variation of this embodiment, the electronic circuit resides for preset time intervals in the low-power state, the first-intermediate power state, and the maximum-sustainable power state, before transitioning to other states.
[0013] In a further variation, the electronic circuit resides in the boosted power state either for a preset time interval or until the electronic circuit exceeds a maximum thermal energy level.
[0014] In a further variation, the electronic circuit returns to the maximum-sustainable power state after residing in the boosted power state.
[0015] In a further variation, the electronic circuit activates a busy signal when the electronic circuit is busy performing computational work.
[0016] In a further variation, the electronic circuit returns to the low-power state from a given state if the busy signal is deactivated while the electronic circuit is in the given state.
[0017] In a further variation, the electronic circuit recovers computational work lost because of the lower operating speeds in the low-power state and the first-intermediate power state by temporarily operating above maximum sustainable frequency and voltage in the boosted power state.
[0018] In a further variation, upon recognizing the need for performance beyond the first-intermediate power state, the electronic circuit enters a second-intermediate power state before entering the maximum-sustainable power state.
[0019] In a further variation, upon recognizing the need for more performance beyond the second-intermediate power state, the electronic circuit enters one or more additional power states before entering the maximum-sustainable power state.
[0020] In a further variation, if the thermal energy of a cooling system associated with the electronic circuit exceeds a maximum level, the electronic circuit does not enter the boosted power state but instead enters the maximum-power state.
[0021] In a further variation, the thermal energy of the cooling system is determined by measuring the temperature of a heat sink within the cooling system.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 illustrates a computer system in accordance with an embodiment of the present invention.
[0023] FIG. 2 illustrates a state-diagram of the transition between power states of the electronic circuit in accordance with an embodiment of the present invention.
[0024] FIG. 3A illustrates four possible power states of the electronic circuit in accordance with an embodiment of the present invention.
[0025] FIG. 3B presents a table illustrating the computational work done by the electronic circuit in a given time in accordance with the power states of FIG. 3A .
DETAILED DESCRIPTION
[0026] The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
[0027] The data structures and code described in this detailed description are typically stored on a computer readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.
[0000] Computer System
[0028] FIG. 1 illustrates a computer system 100 in accordance with an embodiment of the present invention. Computer system 100 can generally include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a device controller, and a computational engine within an appliance.
[0029] Computer system 100 includes a number of components, including one or more computational engines, such as microprocessors, located within processor complex 111 . These processors are coupled to memory 116 through memory controller 115 . Memory controller 115 can include any type of circuitry that coordinates accesses to memory 116 . Memory 116 can include any type of random access memory for storing code and data to be accessed by processors within processor complex 111 .
[0030] Computer system 100 also includes components related to controlling temperature. These components include heat sink 112 , thermal sensor 114 and thermal energy level signal 102 . Heat sink 112 dissipates heat from processor complex 111 . Note that heat sink 112 can additionally dissipate heat from other heat-producing components within computer system 100 . Thermal sensor 114 is coupled to heat sink 112 . Thermal sensor 114 provides a measurement of the thermal energy level of heat sink 112 to power management unit 110 through thermal energy level signal 102 .
[0031] Power management unit 110 controls the operating frequency and supply voltage for processor complex 111 . Power management unit 110 raises or lowers the frequency and voltage levels for computer system 100 in response to signals received from power management unit control 101 , thermal energy level signal 102 and processor busy signal 103 . Power management unit 110 does so by communicating with a special-purpose frequency/voltage controller 108 , which sets the DC voltage for switching regulator 104 and selects the output frequency for programmable clock frequency generator 106 .
[0032] Processor complex 111 also communicates processor busy signal 103 to power management unit 110 . Processor busy signal 103 is asserted when processor complex 111 is performing a computational task. Otherwise, processor busy signal 103 is not asserted.
[0033] Programmable clock frequency generator 106 can be implemented in a number of ways. One implementation uses multiple phase-lock loops (PLLs). Another implementation uses a single PLL, which includes divided outputs for the different frequencies (e.g., divide-by-two).
[0034] In an alternative embodiment of the present invention, some or all of the power management unit 110 , frequency/voltage controller 108 , switching regulator 104 and programmable clock frequency generator 106 are implemented within processor complex 111 through software.
[0035] When the processors are not executing computationally intensive tasks, the system operates processor complex 111 at low frequency and voltage levels. Note that for typical users and applications, the ratio between idle or near-idle time and computationally intensive time is high. Processor complex 111 therefore generally operates at the lower frequency and voltage for a significant portion of its overall operating time.
[0036] Heat sink 112 has sufficient capacity to dissipate the thermal energy generated by processor complex 111 while processor complex 111 is operating at a maximum-sustainable speed. When processor complex 111 is operating at lower speeds the excess thermal energy dissipation capacity of the heat sink 112 leads to a lower operating temperature.
[0000] Process of Selectively Controlling Operating Frequency and Voltage
[0037] FIG. 2 presents a flowchart illustrating the process of controlling an operating frequency and voltage for an electronic circuit in accordance with an embodiment of the present invention.
[0038] The process starts with the electronic circuit operating in a low-power state ( 200 ). In the low-power state, the electronic circuit is operating with low voltage and frequency (for example, a voltage of 1.1V and a frequency of 800 MHz), thereby minimizing power consumption.
[0039] When the electronic circuit starts to perform computational work, timer[ 1 ] is activated ( 201 ). While timer[ 1 ] is counting down, the electronic circuit continues to operate in the low-power state.
[0040] When timer[ 1 ] expires, the electronic circuit enters a first-intermediate state by increasing the voltage to a first-intermediate voltage, such as 1.2 V, increasing the frequency to a first-intermediate frequency, such as 1 GHz. and starting timer[ 2 ] ( 202 ). In the first-intermediate state, the power consumption of the electronic circuit is below its maximum level, but the performance is also below its maximum level.
[0041] When timer[ 2 ] expires, the electronic circuit enters the maximum-sustainable power state by increasing the voltage to a maximum sustainable voltage, such as 1.3 V, increasing the frequency to a maximum sustainable frequency, such as 1.2 GHz, and starting timer[N] ( 203 ). In the maximum-sustainable power state, the power consumption and performance of the electronic circuit are at the highest levels that the circuit can maintain continuously.
[0042] When timer[N] expires, if the thermal energy level of the electronic circuit is above a threshold value, the circuit remains in the maximum-sustainable power state ( 205 ). Alternatively, if the thermal energy level is below the threshold value when timer[N] expires, the electronic circuit enters the boosted power state by increasing the voltage to a voltage that exceeds the maximum sustainable voltage, such as 1.5 V, increasing the frequency to a frequency that exceeds the maximum sustainable frequency, such as 1.5 GHz, and starting a boosted power state timer ( 204 ). In this boosted power state, the power consumption and performance of the electronic circuit are above maximum sustainable levels. Note that the electronic circuit can only operate in this boosted power state for a limited time because the thermal energy of the electronic circuit exceeds the heat removing capacity of the cooling system. The thermal energy level of the system will consequently rise until it exceeds a threshold value.
[0043] If the thermal energy level exceeds the threshold value while the electronic circuit is operating in the boosted power state, the electronic circuit immediately exits the boosted power state and returns to a maximum-sustainable power state ( 205 ).
[0044] When the boosted power state timer expires, the electronic circuit reenters the maximum-sustainable power state by decreasing the voltage to a maximum sustainable voltage, such as 1.3 V, and decreasing the frequency to a maximum sustainable frequency, such as 1.2 GHz ( 205 ).
[0045] Regardless of the state of operation, whenever the electronic circuit is no longer performing computational work, the electronic circuit immediately returns to the low-power state ( 200 ).
[0046] Note that the single intermediate state can include one or more additional intermediate states, with different voltage and frequency levels.
[0000] Balancing Circuit Performance and Power Savings
[0047] FIG. 3A presents a graph of power level versus time in accordance with one embodiment of the present invention. The power-level axis of the graph indicates the operating power level of the electronic circuit as a percentage of the maximum sustainable level. The time axis indicates the progression of time.
[0048] FIG. 3B presents a tabular form of the information presented graphically in FIG. 3A . The “Interval” and “Power Level” headings in FIG. 3B relate directly to the axis on in FIG. 3A . The “Power State” heading in FIG. 3B relates to the power state name associated with a given “Power Level.” The “Interval Time” shows the time that the electronic circuit resides in the associated “Power State.” The “Performance Level” heading in FIG. 3B shows the performance level of the electronic circuit as a percentage of the maximum sustainable performance level. The “Interval Gain or Loss” and the “Net Gain or Loss” in FIG. 3B are effective computational work gains and losses with respect to the possible computational work that could be completed by running the electronic circuit in the maximum-sustainable power state for the same time interval.
[0049] In a given time interval, the electronic circuit performs an amount of computational work that is proportional to the operating frequency of the electronic circuit. Note that power level is approximately related to frequency by P∝V 2 f. Since power is proportional to frequency, the power level associated with a given power state is directly correlated to the amount of computational work that the electronic circuit can perform in that power state.
[0050] As shown in FIG. 3B , in the “T1” interval, the electronic circuit initially operates in the low-power state. The system stays in the low-power state for 10 ms and operates at 25% power and 50% performance as illustrated in FIG. 3A . The effective computational work lost while operating in the low-power state is 5 ms, as shown in the “Interval Gain or Loss” column of interval “T 1 ” of FIG. 3B . In other words, the electronic circuit has to run for an additional 5 ms in the maximum-sustainable power state to compensate for the work lost while executing in the low-power state.
[0051] In the “T2” interval of FIG. 3B , the electronic circuit enters a first-intermediate power state. The system operates stays in the first-intermediate power state for 10 ms and operates at 50% power and 70% performance as illustrated in FIG. 3A . While operating in the first-intermediate power state, the electronic circuit loses 3 ms of computational work. The electronic circuit is now 8 ms behind, as shown in the “Net Gain or Loss” column for interval “T 2 ” in FIG. 3B .
[0052] In the “T3” interval of FIG. 3B , the electronic circuit enters the maximum-sustainable power state. The system stays in the maximum-sustainable power state for 10 ms and operates at 100% power and 100% performance as illustrated in FIG. 3A . Since the electronic circuit is operating in the maximum-sustainable power state, no computational work is lost. The electronic circuit remains 8 ms behind, as shown in the “Net Gain or Loss” column for interval “T 3 ” in FIG. 3B .
[0053] In the “T4” interval of FIG. 3B , the electronic circuit enters the boosted power state. The system stays in the boosted power state for 40 ms and operates at 145% power and 120% performance as illustrated in FIG. 3A . The computational work gained by operating in the boosted power state is 8 ms. Hence, the electronic circuit has recovered the computational work lost in the preceding states and is 0 ms behind, as shown in the “Net Gain or Loss” column for interval “T 4 ” in FIG. 3B .
[0054] The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims.
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One embodiment of the present invention provides a system that facilitates selectively increasing the operating frequency of an electronic circuit, such as a computer system. The system begins by operating in a low-power state with the frequency and voltage of the electronic circuit set to low levels. Upon recognizing the need for performance beyond the low power level, the electronic circuit enters the first-intermediate power state. In this first-intermediate power state, the frequency and voltage are set to first-intermediate levels. Upon recognizing the need for performance beyond the first-intermediate power state, the electronic circuit enters the maximum-sustainable power state. In this power state, the frequency and voltage are set to maximum sustainable levels. Upon recognizing the need for performance beyond the maximum-sustainable power state, the electronic circuit temporarily enters a boosted power state beyond the maximum-sustainable power state. In this boosted power state, the frequency and voltages are set to levels beyond the maximum sustainable levels.
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This Application claims benefit of Provisional Application Ser. No. 60/039,275 filed Feb. 28, 1997.
FIELD OF THE INVENTION
The present invention relates to the field of distribution and usage rights enforcement for digitally encoded works, and in particular to identification of non-authorized copies of digitally encoded works that have been rendered.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,629,980 entitled “System For Controlling the Distribution And Use Of Digital Works”, issued May 13, 1997, describes a system which provides for the secure and accounted for distribution of digitally encoded works (hereinafter digital works). However, once a digital work leaves the digital domain, e.g. it is printed out, played or otherwise rendered, it is no longer secure and can be subjected to unauthorized copying. This is a problem for all rendered digital works.
Two known techniques for protecting digital works by imparting information onto the digital work itself are “watermarking” and “fingerprinting”. The term watermark historically refers to a translucent design impressed on paper during manufacture which is visible when the paper is held to the light. Because watermarks are impressed using combinations of water, heat, and pressure, they are not easy to add or alter outside of the paper factory. Watermarks are used in making letterheads and are intended to indicate source and that a document is authentic and original and not a reproduction.
One technique for creating such a watermark when a digital work is printed is described in U.S. Pat. No. 5,530,759 entitled “Color Correct Digital Watermarking of Images” issued Jun. 25, 1996. In this approach the watermark image is combined with the digital image to create the watermarked image. The watermark image acts as a template to change the chromacity of corresponding pixels in the digital image thus creating the watermark. In any event, these notices server as social reminders to people to not make photocopies.
The term watermark is now used to cover a wide range of technologies for marking rendered works, including text, digital pictures, and digital audio with information that identifies the work or the publisher. Some watermarks are noticeable to people and some are hidden. In some kinds of watermarks, the embedded information is human readable, but in other kinds the information can only be read by computers.
The term fingerprint is sometimes used in contrast with watermarks to refer to marks that carry information about the end user or rendering event rather than the document or publisher. These marks are called “fingerprints” because they can be used to trace the source of a copy back to a person or computer that rendered the original.
The same technologies and kinds of marks can be used to carry both watermark and fingerprint information. In practice, it is not only possible but often desirable and convenient to combine both kinds of information—for watermarks and fingerprints—in a single mark.
With respect to paper based documents, the simplest approach to providing a mark is a graphical symbol or printed notice that appears on each page. This is analogous to a copyright notice. Such notices can be provided by the publisher in the document source or added later by a printer. These notices serve as social reminders to people to not make photocopies.
Other approaches hide information in the grey codes (or intensity) on a page. Although in principle such approaches can embed data in greycode fonts, their main application so far has been for embedding data in photographs. One set of approaches is described by Cox et al. in a publication entitled “Secure spread spectrum watermarking for Multimedia”, NEC Research Institute Technical Report 95-10, NEC Research Institute, Princeton, N.J. 08540. To decode data encoded in the approached described by Cox et al. requires comparing the encoded picture with the original to find the differences. The advantage of these approaches is that they can embed the data in such a way that it is very difficult to remove, not only by mechanical means but also by computational means.
As described above, watermarks need not be perceptible to the viewer. For example, one technique is to embed data in the white space of a document. An example of this kind of approach was described by Brassil, et al. In a publication entitled “Electronic marking and identification techniques to discourage document copying”, IEEE Journal on Selected Areas in Communications, Vol. 13, No. 8 pages 1495-1504, October 1995. The idea is to slightly vary the spacing of letters and lines in a digital work. The advantages of this approach are that it is not visible and is hard to remove. A disadvantage is that it has a very limited capacity for carrying data—only a few bytes per page.
Another watermarking scheme for use in digital works representing images is available from the Digimarc Corporation. The Digimarc watermark is invisible and is used to convey ownership information relating to the image. From the Digimarc World Web Page describing their technology (URL http://www.digimarc.com/wt_page.html): “A Digimarc watermark imitates naturally occurring image variations and is placed throughout the image such that it cannot be perceived. To further hide the watermark, the Digimarc watermarking process is perceptually adaptive—meaning it automatically varies the intensity of the watermark in order to remain invisible in both flat and detailed areas of an image.” Reading of the Digimarc watermark is through a Digimarc reader which can extract the watermark from the image.
Other related prior art includes Daniele, U.S. Pat. No. 5,444,779, on “Electronic Copyright Royalty Accounting System for Using Glyphs”, which discloses a system for utilizing a printable, yet unobtrusive glyph or similar two-dimensionally encoded mark to identify copyrighted documents. Upon attempting to reproduce such a document, a glyph is detected, decoded and used to accurately collect and/or record a copyright royalty for the reproduction of the document or to prevent such reproduction. Furthermore, the glyph may also include additional information so as to enable an electronic copyright royalty accounting system, capable of interpreting the encoded information to track and/or account for copyright royalties which accrue during reproduction of all or portions of the original document.
Merkle, etl al., U.S. Pat. No. 5,157,726 entitled “Document Copy Authentication” describes a system for document authentication which utilizes an ID card coupled to a copying machine capable of reading the ID card. The copying machine imparts digitally encoded identification information, e.g. a digital signature, onto a copied document based on information contained in the ID card. The copied document can then be authenticated by scanning the document to extract and decode the digital signature.
SUMMARY OF THE INVENTION
A trusted rendering system for use in a system for controlling the distribution and use of digital works is disclosed. The currently preferred embodiment of the present invention is implemented as a trusted printer. However, the description of the invention herein applies to any rendering device. A trusted printer facilitates the protection of printed documents which have been printed from a system which controls the distribution and use of digital works. The system for controlling distribution and use of digital works provides for attaching persistent usage rights to a digital work. Digital works are transferred in encrypted form between repositories. The repositories are used to request and grant access to digital works. Such repositories are also coupled to credit servers which provide for payment of any fees incurred as a result of accessing or using a digital work.
The present invention extends the existing capabilities of the system for controlling distribution and use of digital works to provide a measure of protection when a document is printed. The present invention adds to the system the ability to include watermark information to a document when it is rendered (i.e. a Print right associated with the document is exercised). In the currently preferred embodiment of a trusted printer, the watermark is visible. However, other “invisible” watermarking technologies may also be used. The watermark data typically provides information relating to the owner of a document, the rights associated with that copy of the document and information relating to the rendering event (e.g. when and where the document was printed). This information will typically aid in deterring or preventing unauthorized copying of the rendered work. It is worth noting that the present invention further provides for multiple types of watermarks to be provided on the same digital work.
Specification of the watermark information is preferably added to a document at the time of assigning render or play rights to the digital work. With respect to printed digital works, at the time of page layout special watermark characters are positioned on the document. When the document is printed, a dynamically generated watermark font is created which contains the watermark information that was specified in the print right. The font of the watermark characters is changed to the dynamically generated watermark font. The dynamically generated watermark font is created using an embedded data technology such as the glyph technology developed by the Xerox Corporation and described in U.S. Pat. No. 5,486,686 entitled “Hardcopy Lossless Data Storage and Communications For Electronic Document Processing Systems”, which is assigned to the same assignee as the present application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the basic interaction between repository types in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention.
FIG. 2 is an illustration of a repository coupled to a credit server for reporting usage fees as may be used in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention.
FIG. 3 is an illustration of a printer as a rendering system as may be utilized in a system for controlling the distribution and use of digital works in the currently preferred embodiment of the present invention.
FIG. 4 is a block diagram illustrating the functional elements of a trusted printer repository in the currently preferred embodiment of the present invention.
FIG. 5 is a flowchart of the basic steps for digital work creation for printing on a trusted printer as may be performed in the currently preferred embodiment of the present invention.
FIG. 6 is an illustration of a usage rights specification for a digital work that may be printed on a users trusted printer in the currently preferred embodiment of the present invention.
FIG. 7 is an illustration of a usage rights specification for a digital work that may only be printed on a shared trusted printer residing on a network in the currently preferred embodiment of the present invention.
FIG. 8 is an illustration of a printed page having a glyph encoded watermark.
FIG. 9 is an illustration of a set of sample embedded data boxes having different storage capacities as may be used as watermark characters of a watermark font set in the currently preferred embodiment of the present invention.
FIG. 10 is an illustration of a print right having the watermark information specified as may be used set in the currently preferred embodiment of the present invention.
FIG. 11 is a flowchart summarizing the basic steps for a creator to cause watermarks to be placed in their documents as may be performed in the currently preferred embodiment of the present invention.
FIG. 12 is a flowchart of the steps required for printing a document as may be performed in the currently preferred embodiment of the present invention.
FIG. 13 is a flowchart outlining the basic steps for extracting the embedded data as may be performed in the currently preferred embodiment of the present invention.
FIG. 14 is an illustration of an implementation of the present invention as a trust box coupled to a computer based system.
FIG. 15 is a flowchart illustrating the steps involved in printing a digital work using the trust box implementation of FIG. 14 .
FIG. 16 is an illustration of an implementation of the present invention is as a printer server.
FIG. 17 is a flowchart illustrating the steps involved in printing a digital work using the printer server implementation of FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
A trusted rendering device for minimizing the risk of unauthorized copying of rendered digital works is described. The risk of unauthorized copying of digital documents comes from three main sources: interception of digital copies when they are transmitted (e.g., by wiretapping or packet snooping); unauthorized use and rendering of digital copies remotely stored, and unauthorized copying of a rendered digital work. The design of trusted rendering devices described herein addresses all three risks.
Trusted rendering combines four elements: a usage rights language, encrypted on-line distribution, automatic billing for copies, and digital watermarks for marking copies that are rendered.
Usage Rights language. Content providers indicate the terms, conditions, and fees for printing documents in a machine-readable property rights language.
Encrypted Distribution. Digital works are distributed from trusted systems to trusted rendering devices via computer networks. To reduce the risk of unauthorized interception of a digital work during transmission, it is encrypted. Communication with the rendering system is by way of a challenge-response protocol that verifies the authorization and security of the rendering device.
Automatic Billing. To ensure a reliable income stream to content providers, billing of royalties is on-line and automatic.
Watermarks. Finally, to reduce the risk of copying of rendered works, the rendered work is watermarked to record data about the digital work and the rendering event. Furthermore, watermarks are designed to make copies distinguishable from originals. As will be described below, watermark information is specified within a rendering or play right in the usage rights language.
The currently preferred embodiment of the present invention is implemented as a trusted printer. The foregoing description will be directed primarily to printers, but the concepts and techniques described therein apply equally to other types of rendering systems such as audio players, video players, displays or multi-media players.
OVERVIEW OF A SYSTEM FOR CONTROLLING THE DISTRIBUTION AND USE OF DIGITAL WORKS
The currently preferred embodiment of the present invention operates in a system for controlling the distribution and use of digital works is as described in issued U.S. Pat. No. 5,629,980, entitled “System for Controlling the Distribution and Use of Digital Works” and which is herein incorporated by reference. A digital work is any written, audio, graphical or video based work including computer programs that have been translated to or created in a digital form, and which can be recreated using suitable rendering means such as software programs. The system allows the owner of a digital work to attach usage rights to the work. The usage rights for the work define how it may be used and distributed. Digital works and their usage rights are stored in a secure repository. Digital works may only be accessed by other secure repositories. A repository is deemed secure if it possesses a valid identification (digital) certificate issued by a Master repository and can prove its identity in a challenge response protocol.
The usage rights language for controlling a digital work is defined by a flexible and extensible usage rights grammar. The usage rights language of the currently preferred embodiment is provided in Appendix A. Conceptually, a right in the usage rights grammar is a label attached to a predetermined behavior and defines conditions to exercising the right. For example, a COPY right denotes that a copy of the digital work may be made. A condition to exercising the right is the requester must pass certain security criteria. Conditions may also be attached to limit the right itself. For example, a LOAN right may be defined so as to limit the duration of which a work may be LOANed. Conditions may also include requirements that fees be paid.
A repository is comprised of a storage means for storing a digital work and its attached usage rights, an external interface for receiving and transmitting data, a processor and a clock. A repository generally has two primary operating modes, a server mode and a requester mode. When operating in a server mode, the repository is responding to requests to access digital works. When operating in requester mode, the repository is requesting access to a digital work.
Generally, a repository will process each request to access a digital work by examining the work's usage rights. For example, in a request to make a copy of a digital work, the digital work is examined to see if such “copying” rights have been granted, then conditions to exercise the right are checked (e.g. a right to make 2 copies). If conditions associated with the right are satisfied, the copy can be made. Before transporting the digital work, any specified changes to the set of usage rights in the copy are attached to the copy of the digital work.
Repositories communicate utilizing a set of repository transactions. The repository transactions embody a set of protocols for establishing secure session connections between repositories, and for processing access requests to the digital works. Note that digital works and various communications are encrypted whenever they are transferred between repositories.
Digital works are rendered on rendering systems. A rendering system is comprised of at least a rendering repository and a rendering device (e.g. a printer, display or audio system). Rendering systems are internally secure. Access to digital works not contained within the rendering repository is accomplished via repository transactions with an external repository containing the desired digital work. As will be described in greater detail below, the currently preferred embodiment of the present invention is implemented as a rendering system for printing digital works.
FIG. 1 illustrates the basic interactions between repository types in the present invention. As will become apparent from FIG. 1, the various repository types will serve different functions. It is fundamental that repositories will share a core set of functionality which will enable secure and trusted communications. Referring to FIG. 1, a repository 101 represents the general instance of a repository. The repository 101 has two modes of operations; a server mode and a requester mode. When in the server mode, the repository will be receiving and processing access requests to digital works. When in the requester mode, the repository will be initiating requests to access digital works. Repository 101 may communicate with a plurality of other repositories, namely authorization repository 102 , rendering repository 103 and master repository 104 . Communication between repositories occurs utilizing a repository transaction protocol 105 .
Communication with an authorization repository 102 may occur when a digital work being accessed has a condition requiring an authorization. Conceptually, an authorization is a digital certificate such that possession of the certificate is required to gain access to the digital work. An authorization is itself a digital work that can be moved between repositories and subjected to fees and usage rights conditions. An authorization may be required by both repositories involved in an access to a digital work.
Communication with a rendering repository 103 occurs in connection with the rendering of a digital work. As will be described in greater detail below, a rendering repository is coupled with a rendering device (e.g. a printer device) to comprise a rendering system.
Communication with a master repository 105 occurs in connection with obtaining an identification certificate. Identification certificates are the means by which a repository is identified as “trustworthy”. The use of identification certificates is described below with respect to the registration transaction.
FIG. 2 illustrates the repository 101 coupled to a credit server 201 . The credit server 201 is a device which accumulates billing information for the repository 101 . The credit server 201 communicates with repository 101 via billing transaction 202 to record billing transactions. Billing transactions are reported to a billing clearinghouse 203 by the credit server 201 on a periodic basis. The credit server 201 communicates to the billing clearinghouse 203 via clearinghouse transaction 204 . The clearinghouse transactions 204 enable a secure and encrypted transmission of information to the billing clearinghouse 203 .
RENDERING SYSTEMS
A rendering system is generally defined as a system comprising a repository and a rendering device which can render a digital work into its desired form. Examples of a rendering system may be a computer system, a digital audio system, or a printer. In the currently preferred embodiment, the rendering system is a printer. In any event, a rendering system has the security features of a repository. The coupling of a rendering repository with the rendering device may occur in a manner suitable for the type of rendering device.
FIG. 3 illustrates a printer as an example of a rendering system. Referring to FIG. 3, a printer system 301 has contained therein a printer repository 302 and a print device 303 . It should be noted that the dashed line defining printer system 301 defines a secure system boundary. Communications within the boundary is assumed to be secure and in the clear (i.e. not encrypted). Depending on the security level, the boundary also represents a barrier intended to provide physical integrity. The printer repository 302 is an instantiation of the rendering repository 105 of FIG. 1 . The printer repository 302 will in some instances contain an ephemeral copy of a digital work which remains until it is printed out by the print engine 303 . In other instances, the printer repository 302 may contain digital works such as fonts, which will remain and be billed based on use. This design assures that all communication lines between printers and printing devices are encrypted, unless they are within a physically secure boundary. This design feature eliminates a potential “fault” point through which the digital work could be improperly obtained. The printer device 303 represents the printer components used to create the printed output.
Also illustrated in FIG. 3 is the repository 304 . The repository 304 is coupled to a printer repository 302 . The repository 304 represents an external repository which contains digital works.
FIG. 4 is a block diagram illustrating the functional elements of a trusted printer repository. Note that these functional elements also would be present in any rendering repository. Referring to FIG. 4, the functional embodiment is comprised of an operating system 410 , core repository services 411 , and print repository functions 412 . The operating system 410 is specific to the repository and would typically depend on the type of processor being used to implement the repository. The operating system 401 would also provide the basic services for controlling and interfacing between the basic components of the repository.
The core repository services 411 comprise a set of functions required by each and every repository. For a trusted printer repository the core repository services will include engaging in a challenge response protocol to receive digital works and decryption of received digital data.
The print repository functions 412 comprise functionality for rendering a work for printing as well as gathering data for and creating a digital watermark. The functionality unique to a print repository will become apparent in the description below (particularly with respect to the flowchart of FIG. 12 ).
BASIC STEPS FOR DIGITAL WORK CREATION FOR PRINTING ON A TRUSTED PRINTER
FIG. 5 is a flowchart illustrating the basic steps for creating a digital work that may be printed on a trusted printer so that the resulting printed document is also secure. Note that a number of well known implementation steps, e.g. encryption of digital works, have been omitted in order to not detract from the basic steps. First, a digital work is written, assigned usage rights including a print right which specifies watermark information and is deposited in repository 1 , step 501 . As will be described in more detail below, the assignment of usage rights is accomplished through the use of a rights editor. Deposit of the digital work into repository 1 is an indication that it is being placed into a controlled system. Next, repository 1 receives a request from repository 2 for access to the digital work, step 502 and repository 1 transfers a copy of the digital work to repository 2 , step 503 . For the sake of this example, it is assumed that a “trusted” session between repository 1 and repository 2 has been established. The challenge response protocol used in this interaction is described in the aforementioned U.S. Pat. No. 5,629,980 and thus no further discussion on the challenge response protocol is deemed necessary.
Repository 2 then receives a user request to print the digital work, step 504 . Repository 2 then establishes a trusted session with a printer repository of is the printing system on which the digital work will be printed, step 505 . The printer repository receives the encrypted digital work and determines if it has a print right, step 506 . If the digital work has the print right, the printer repository decrypts the digital work and generates the watermark that will be printed on the digital work, step 507 . The printer repository then transmits the decrypted digital work with the watermark to a printer device for printing, step 508 . For example, the decrypted digital work may be a Postscripts file of the digital work.
CONTROLLING PRINTING WITH THE USAGE RIGHTS GRAMMAR
A key concept in governing sale, distribution, and use of digital works is that publishers can assign “rights” to works that specify the terms and conditions of use. These rights are expressed in a rights language as described in the aforementioned U.S. Pat. No. 5,629,980. The currently preferred grammar is provided herein in Appendix A. It is advantageous to specify watermark information within a rendering or play right within the grammar for a number of reasons. First, specification in this manner is technology independent. So different watermarking technologies may be used or changed without altering the digital document. Second, multiple watermarking technologies may be applied to the same digital work, e.g. a visible watermarking technology and an invisible watermarking technology. So if the visible watermark is removed, the invisible one may remain. Third, the watermark information to be placed on the digital work can be associated with the rendering event, rather than the distribution event. Fourth, the watermark information can be extended to include the entire distribution chain of the digital work. Fifth, security and watermarking capabilities of a rendering system may be specified as a condition of rendering. This will further insure the trusted rendering of the digital work.
As a result of these advantages, this type of specifying watermark information fully supports the Superdistribution of digital works. Superdistribution is distribution concept where every possessor of a digital work may also be a distributor of the digital work, and wherein every subsequent distribution is accounted for.
When a publisher assigns rights to a digital work, the usage rights enables them to distinguish between viewing (or playing) rights and print rights. Play rights are used to make ephemeral, temporary copies of a work such as an image of text on a display or the sound of music from a loudspeaker. Print rights are used to make durable copies, such as pages from a laser printer or audio recordings on a magnetic media.
Example—TRUSTED PRINTING FROM A PERSONAL COMPUTER
FIG. 6 is an example of the usage rights for a digital work which enables trusted printing from a personal computer. Referring to FIG. 6, various tags are used in for the digital work. The tags “Description” 601, “Work-ID” 602 and “Owner” 603 provide identification information for the digital work.
Usage rights are specified individually and as part of a group of rights. The Rights-Group 604 has been given a name of “Regular”. The bundle label provides for a fee payee designation 605 and a minimum security level 606 that are applied to all rights in the group. The fee payee designation 605 is used to indicate who will get paid upon the invocation of a right. The minimum security level 606 is used to indicate a minimum security level for a repository that wishes to access the associated digital work.
The rights in the group are then specified individually. The usage rights specify no fee for transferring 608 , deleting 609 or playing 610 , but does have a five dollar fee for making a digital copy 607 . It also has two Print rights 611 and 612 , both requiring a trusted printer (specified by 613 ) The first Print right 611 can be exercised if the user has a particular prepaid ticket (specified by 614 ). The second print right has a flat fee of ten dollars (specified by 615 ). The example assumes that the digital work can be transmitted to a user's computer by exercising the Copy right, and that the user can play or print the work at his or her convenience using the Play and Print rights. Fees are logged from the users workstation whenever a right is exercised.
Also illustrated in FIG. 6 are watermark specifications 616 and 617 . The particular detail for the watermark specifications 616 and 617 is described below with reference to FIG. 10 . Example - Trusted Printing to an Internet Printer FIG. 7 illustrates a different set of rights for the same digital book. In this version, the publisher does not want digital delivery to be made to a consumer workstation. A practical consideration supporting this choice may be that the publisher wants to minimize the risk of unauthorized digital copying and is requires a higher level of security than is provided by trusted systems on available workstations. Instead, the publisher wants the book to be sent directly from an on-line bookstore to a trusted printer. Printing must be prepaid via digital tickets (see fee specification 701 ). To enable digital distribution to authorized distributors but not directly to consumers, the publisher requires that both parties in a Copy and Transfer right to have an authorizing digital license (see certificate specifications 702 and 703 ). Lacking such a license, a consumer can not access the work at a workstation. Instead, he or she must print the work.
Also illustrated in FIG. 7 is the watermark specifications 704 . The watermark specification 704 is described in greater detail below with respect to FIG. 10 .
WATERMARKS AND FINGERPRINTS
Three main requirements for watermarks on trusted printers have been identified:
Social Reminder. This requirement is for a visible printed indication about whether photocopying is permitted. This could be a printed statement on the document or an established icon or symbol within a corporation indicating a security level for the document.
Auditing. This requirement is for a way to record information on the document about the printing event, such as who owns the print rights, whether photocopying is permitted, and what person or printer printed the document and when the document was printed.
Copy Detection. This requirement is a way for differentiating between printed originals and photocopies. In general, this requirement involves using some print patterns on the page which tend to be distorted by photocopiers and scanners. For some patterns, the difference between copies and printed original is detectable by people; for other patterns, the difference is automatically detectable by a computer with a scanner.
In the currently preferred embodiment, watermarks are created with embedded data technology such as glyph technology developed by the Xerox corporation. Glyph technology as it is used as embedded data printed on a medium is described in U.S. Pat. No. 5,486,686 entitled “Hardcopy Lossless Data Storage and Communications For Electronic Document Processing Systems”, which is incorporated by reference herein. Using glyphs as digital watermarks on printed documents is described in co/pending application Ser. No. 08/734, 570 entitled “Quasi-Reprographics With Variable Embedded Data With Applications To Copyright Management, Distribution Control, etc.”, which is assigned to the same assignee as the present application and is incorporated by reference herein.
Generally, embedded data technology is used to place machine readable data on a printed medium. The machine readable data typically is in a coded form that is difficult if not impossible for a human to read. Another example of an embedded data technology is bar codes.
Embedded data technology can be used to carry hundreds of bits of embedded data per square inch in various grey patterns on a page. Preferably, glyphs are used because the marks representing the encoded data can be used to create marks which are more aesthetically appealing then other embedded data technologies. With careful design, glyphs can be integrated as graphical elements in a page layout. Glyphs can be used with any kind of document. Glyph watermarks to carry document identification can be embedded by the publisher; while glyphs carrying data about a print event can be added to the watermark at the time of printing by a printing system. Both document identification and fingerprinting data can be embedded in the same watermark.
It should be noted that a disadvantage of glyphs and with all forms of visible and separable watermarks, is that with mechanical or computational effort, they can be removed from a document.
FIG. 8 illustrates an example of a document image having a glyph encoded watermark. Referring to FIG. 8, a document page 801 has various text 802 . Also included is a glyph encoded watermark 803 . Note that the document is not limited to text and may also include image or graphical data.
INTEGRATING EMBEDDED DATA AS WATERMARKS INTO TRUSTED PRINTING SYSTEMS
This section describes briefly how embedded data technology can be used in trusted printing systems to embed watermarking data. How glyphs and watermark data are handled at each stage in creating, publishing, and printing a document is discussed.
It has been determined that for integrating embedded data such as glyphs into trusted printing systems, the requirements include:
Document designers such as authors and publishers must be able to specify on a page by page basis the position and shape of watermarks, so that they can be incorporated into the design of the document.
The approach should be compatible with mainline document creation (e.g. word processing) systems.
The approach should work within the protocols of existing printers.
The approach should carry the fingerprint (or run-time) data in Usage Rights specifications.
The approach should not significantly slow down printing.
Herein the term media-dependent data is used to refer to information about how a watermark is located and shaped within the document content. The approach depends on the use of Usage Rights to express the data to be encoded in the watermark.
Document Creation
Publishers use a wide variety of tools to create documents. Different text editors or word processors provide different ways and degrees of control in laying out text, pictures and figures. One thing that all text editors have is a way to locate text on a page. In effect, this is a lowest common denominator in abilities for all systems.
Exploiting this common capability provides insight about how to use glyphs to represent watermarks:
Glyph watermarks are organized graphically as rectangular boxes.
Different sized boxes have different capacities for carrying data. On 300 dpi printers, about 300 bytes per inch can be encoded in glyphs. Note that this can represent even more data if the original data is compressed prior to glyph encoding. Note for greater reliability, some data may be repeated redundantly, trading data capacity for reliability.
Each glyph watermark is represented to a document creation program as a character in an initial glyph watermark font. Boxes of different sizes and shapes are represented as different characters for the initial glyph watermark font. When a digital work is printed, the encoding of the data is analogous to calculating and changing the watermark font.
In practice, a designer laying out a document would open a page of a glyph catalog containing glyph boxes of different sizes. The glyph boxes in the catalog would probably contain just test data, e.g. a glyph ASCII encoding of the words “test pattern glyph Copyright © Xerox Corporation 1997. All Rights Reserved”. The designer would determine ahead of time how much data he wants to encode per page, such as 100, 300, 500, or 1000 bytes. The designer would copy a “box” (actually a character) of the corresponding size into their document and locate it where they want it on the page, typically incorporating it as a design element.
FIG. 9 illustrates a set of sample watermark characters (i.e. glyph boxes) having different storage capacities. An actual catalog would contain additional shapes and would be annotated according to the data-carrying capacity of the glyphs.
Note that the glyph encoded watermarks can also be placed in figures, since drawing programs also have the capability to locate characters on a page.
When the creator saves their work, the document creation program writes a file in which characters in the glyph font are used to represent the watermarks. If the creator prints the document at this stage, he will see more or less what the final sold versions will look like except that the test data encoded in the gray tones of the glyph box will later be replaced by the dynamically generated watermark data.
SPECIFYING WATERMARK DATA
When the author or publisher gets ready to publish the work and import it into a system for controlling distribution use of digital works, one of the steps is to assign rights to the work using a Rights Editor. The Rights Editor is a program with which a document owner specifies terms and conditions of using a digital work.
This is the point at which document identification data and also print event data are specified. FIG. 10 illustrates the watermark information specified for a print right. Note that the watermark information specification is optional within the grammar. Referring to FIG. 10, print right 1001 specifies that a purchaser of the document must pay ten dollars to print the document (at fee specification 1002 ). The document must only be printed on a trusted printer of a given type (at printer specification 1003 ). Furthermore, the watermark must embed a particular string “Title: Moby Dog Copyright 1994 by Zeke Jones. All Rights Reserved” and also include various data about the printing event (at Watermark-Tokens specification 1004 ). Note that the watermark tokens specification are used to specify the “fingerprint” information associated with the printing of the digital work. Here the specified printing event data is who printed it out, the name of the institution printing it out, the name of the printer, the location of the printer and the time that the digital work was printed. As will be described below, this information is obtained at print time.
FIG. 11 is a flowchart summarizing the basic steps for a creator to cause watermarks to be placed in their documents. As part of the layout of the textual document the designer determines how much data is required by the watermark, step 1101 . Based on the amount of needed data, a suitable watermark character (e.g. glyph box) is selected, step 1102 . The watermark character is then positioned onto a page (or the pages) of the digital work, step 1103 . Finally, as part of the rights assignment for the digital work document, a print right with a watermark specification is made, step 1104 . At this point, the document can be viewed with the watermark positioned in the desired place(s) on the document. However, the actual fingerprint and other identifying data in an embedded data format has not yet been created. This is created dynamically at print time as described below.
PRINTING THE DIGITAL WORK
The next steps for the digital work are that it is published and distributed. During this process, the digital work is protected by the encryption and other security systems that are employed and the rights travel with the document. Part of this process assures that any printer or workstation that has a copy of the document also has digital certificates which contain information identifying the trusted system, trusted printer, user, and so on (a process described in more detail in issued U.S. Pat. No. 5,629,980).
FIG. 12 is a flowchart of the steps required for printing a document. Referring to FIG. 12, at some point, a user decides to print a document, step 1201 . Typically this is done via a print command invoked through some interface on the users system. This opens a challenge-response protocol between the “user” repository containing the document and the printer repository, step 1202 . During this exchange, the security and watermark capabilities of the printer are checked. If the printer does not have the proper security or watermark capabilities, the digital work cannot be printed on that printer. The printer security level and watermark capabilities are specified in the identification certificate for the printer. Assuming that the printer has the proper security levels and watermark capabilities, the “user” repository then checks that the digital work has the required print right, step 1203 . Assuming that the digital work has required print right the user repository may interface with a credit server to report any required fees for the printing the digital work, step 1204 . Note that the actual billing for the digital work may occur when the right is invoked either when the print exercised or when it can be verified that the document has been printed. The latter case protects the user in the situation wherein printing may become inadvertently terminated before the entire digital work is printed.
A computation is then performed to gather together the information to be embedded in the watermark and to incorporate it into a new font for the watermark character. First the information must be gathered from digital identification certificates belonging to the user or the trusted printer, such as names, locations, and the current date and time, step 1205 . This information is “printed” internally into computer memory, creating a bitmap image of glyph boxes of different sizes, step 1206 . Creation and coding of glyphs is described in the aforementioned U.S. Pat. No. 5,486,686, thus no further discussion on the encoding of glyph patterns is deemed necessary. In any event, this information is then assembled into a font definition, step 1207 .
The digital work is then decrypted and downloaded into the printer, step 1208 . When the digital work is downloaded into the printer, part of the protocol is also to download the new “revised” glyph font, which now has characters corresponding to glyph boxes. This font looks more or less like the one that the publisher used in creating the document, except that the gray codes inside the font boxes now embed the data that the publisher wants to appear in the watermarks on the document.
The printer then prints the digital work, step 1209 . When the document is printed, the glyphs that appear on the pages contain the desired watermark data.
READING THE EMBEDDED DATA CONTAINED IN THE WATERMARK
FIG. 13 is a flowchart outlining the basic steps for extracting the embedded data. First, the printed document is scanned and a digital representation obtained, step 1301 . The location of the watermark and the corresponding embedded data is then found, step 1302 . The watermark may be found using techniques for finding characteristic pixel patterns in the digital representation of the printed document. Alternatively, a template for the document may have been created that could be used to quickly find the watermark location. In any event, the embedded data is extracted from the watermark and decoded, step 1303 . The decoded data is then converted to a s human readable form, step 1304 . This may be on a display or printed out. The data extracted is then used to identify who and where the unauthorized reproduction of the digital work came from.
Note that the means for extraction of the watermark data is dependent on the technology used to embed the watermark data. So while the actual extraction steps may vary, they do not cause departure from the spirit and scope of the present invention.
TRUSTED PRINTER EMBODIMENTS
In the following, two embodiments of trusted printer implementations are described: desktop implementations for personal printers and print server implementations for larger workgroup and departmental printers.
DESKTOP IMPLEMENTATIONS
There is a large and growing install base of personal printers. Typically, such printers are connected to personal computers by serial output ports. In other cases, they are installed on small local area networks serving a few offices.
To serve this market a “trust box” is provided which would be positioned in between the personal computer and the personal printer. The “trust box” would act as a print repository for the trusted printer system. This is a market where the purchase of such hardware would be justified by the convenience of digital delivery to the office, for those documents that publishers are unwilling to send in the clear (i.e. not encrypted). The cost of the trust box offsets either waiting for mail delivery or driving to another location to pick up trusted printer output.
FIG. 14 is an illustration of a trust box in a computer based system. Referring to FIG. 14, a personal computer 1401 is coupled to a network 1402 . The personal computer 1401 itself is part of a trusted system in that it embodies a repository. The personal computer would receive digital works through the network 1402 (e.g. over the Internet). The personal computer 1401 is further coupled to trust box 1403 . The communications between the repository contained in the personal computer 1301 and the trust box 1403 are encrypted for security purposes. Finally, the trust box 1403 is coupled to a printer 1404 . The printer 1404 receives decrypted print streams for printing.
From a conceptual perspective, the personal computer combined with the trust box and printer form a trusted system. The trust box implementation would work with other system elements as illustrated in the steps of the flowchart of FIG. 15 .
Referring to FIG. 15, the consumer contacts the distributor of digital works using, for example, an Internet browser such as Netscape Navigator or Microsoft Explorer, step 1501 . For the sake of brevity, it is assumed that a trusted session is established between the consumers repository and the distributor's repository. Using known user interface methods, the consumer selects a work from a catalog or search service, step 1502 . In this example, it is assumed that the rights holder has associated a Print right with the document, and that all terms and conditions for exercising the right are met by the consumer and the trust box.
Once a work is selected the two repositories begin a purchase transaction, step 1503 . As described in U.S. Pat. No. 5,629,980, there are several variations for billing. For concreteness, it is assumed that there is a billing account associated with the trust box.
Using a helper application (or equivalent), the consumer's repository sends a digital certificate to the distributor which contains the trust box's public key, step 1504 . The certificate itself is signed by a well-known repository, such as the printer's manufacturer.
The distributor repository encrypts the document using DES or some other encryption code, step 1505 . The encryption uses a key length that is compatible with requirements of security and legal constraints. The distributor repository encrypts the document key in an envelope signed by the public key of the printer box, step 1506 . The distributor repository then sends the encrypted document and the envelope along to the consumers workstation.
The personal computer stores the encrypted document in its repository along with the envelope containing the key, step 1507 .
At some point, the user decides to print the document. Using a print program, he issues a print request, step 1508 . His personal computer contacts the trust box, retrieving its identity certificate encrypted in its public key, step 1509 . It looks up the watermark information in certificates from the user, the computer itself, and the printer, step 1510 . It downloads the watermark font to the printer through the trust box, step 1511 .
The print program begins sending the document, one page at a time to the trust box, step 1512 .
The trust box contacts the printer. It decrypts the document giving the document key to a decryption means (e.g. an internal decryption chip), step 1513 . It transmits the document to the printer in the clear, step 1514 . Note that this is one place where a digital copy could be leaked, if a printer emulator was plugged into the print box to act like a printer. Presumably the security level of the trust box is set to a value that reflects the level of risk. The document is then printed, step 1515 . Finally, the trust box reports billing to a Financial Clearinghouse, step 1516 .
The trusted print box design is intended to meet several main design objectives as follows:
Installed Base. This approach is intended to work within the current installed base of desktop or personal printers. Installing a trusted print box requires loading software and plugging standard serial cables between the printer, the trusted print box, and the computer.
Security. The approach inhibits unauthorized photocopying through the use of watermarks. The approach inhibits digital copying by storing digital works in an encrypted form, where the consumer workstation does not have access to the key for decrypting the work.
Printer Limitations. The approach assumes that the user will plug the trusted print box into a standard printer. The printer is assumed to not have the capability of storing extra copies of the digital work.
Building box in Printer. Variations of this approach include incorporating the trusted print box into the printer itself. That variation has the advantage that it does not present the document in the clear along any external connectors.
Weak Link. A weak link in this approach is that there is an external connector that transmits the document in the clear. Although this is beyond the average consumer, it would be possible to build a device that sits between the trusted printer box and the printer that would intercept the work in the clear.
Billing Variations. In the version presented here, the trusted print box has secure storage and programs for managing billing records. A simpler version of the approach would be to keep track of all billing on-line. For example, one way to do this would be to have the document printing start at the time that the customer orders it. In this variation, the document is still sent in encrypted form from the publisher, through the consumer's workstation, decrypted, and sent to the trusted print box, to the printer. The difference is that the trusted print box no longer needs to keep billing records and that the consumer must start printing the document at the time that the document is ordered.
Software-only Variation. Another variation on the desktop printing solution involves only software. The consumer/client purchases the work and orders the right to print it once. The on-line distributor delivers the work, encrypted, one page at a time. The consumer workstation has a program that decrypts the page and sends it to the printer with watermarks, and then requests the next page. At no time is a full decrypted copy available on the consumer's computer. The weak link in this approach is that the consumers computer does gain access to copies of pages of the work in the clear. Although this would be beyond the average consumer, it would be possible to construct software either to mimic runtime decryption software or modify it to save a copy of the work, one page at a time.
PRINTER SERVER IMPLEMENTATIONS
Much of the appeal of trusted printers is to enable the safe and commercial printing of long documents. Such printing applications tend to require the speed and special features of large, shared printers rather than personal printers. Provided herein is an architecture for server-based trusted printers.
Besides the speed and feature differences of the print engines themselves, there are some key differences between server-based trusted printers and desktop trusted printers.
Server-based printers store complete copies of documents in files.
Server-based printers have operating systems and file systems that may be accessible via a network.
Server-based printers have consoles, accessible to dedicated or walk-up operators depending on the installation.
These basic properties of server-based printers create their own risks for document security which need to be addressed. In addition, since server-based printers tend to be high volume and expensive, it is important that the trusted system features not significantly slow down competitive printer performance.
From a conceptual perspective, the print server (including network services and spooling) combined with the printer forms a trusted system.
In abstract and functional terms, the operation of the server implementation is similar to that of the trust box implementation. The difference is that the server performs many of the operations of the trust box.
There are many variations on how the print server may need to interoperate with the other system elements. For example, the transaction with the printer may be with the user's computer or with an on-line repository that the user is communicating with. In the following, the transaction is described as happening from a repository, although that repository may be the users own computer.
FIG. 16 is a block diagram illustrating a print server implementation. Referring to FIG. 16, a consumer workstation 1601 is coupled to publisher repository 1602 . The publisher repository 1602 couples directly with a spooler in printer repository 1603 . The spooler is responsible for scheduling and printing of digital works. The spooler 1603 is coupled to the printer 1604 .
The server implementation would work with other system elements as illustrated in the steps of the flowchart of FIG. 17 . Referring to FIG. 17, the repository contacts the trusted printer's server, engaging in a challenge-response protocol to verify that the printer is of the right type and security level to print the work, step 1701 . These interactions also give the printer public certificates for the repository and user, that are used for retrieving watermark information.
The distributor encrypts the document using DES or some other code, using a key length that is compatible with requirements of security and legal constraints, step 1702 . It encrypts the document key in an envelope signed by the public key of server, step 1703 . It sends the encrypted document to the server, step 1704 .
Note that in some versions of this architecture, different levels of encryption and “scrambling” (less secure) are used on the document at different stages in the server. It is generally important to protect the document in all places where it might be accessed by outside parties. The use of lower security encoding is sometimes used to avoid potentially-expensive decryption steps at critical stages that would slow the operation of the printer.
In any event, the server stores the encrypted document, step 1705 . At some point, the spooler gets ready to print the document. Before starting, it runs a process to create a new version of the glyph font that encodes the watermark data, step 1706 . It looks up the required watermark information in its own certificates as well as certificates from the repository and user.
Finally, the spooler begins imaging the document, one page at a time, step 1707 .
Thus, trusted rendering systems for use in a system for controlling the distribution and use of digital works are disclosed. While the present invention is described with respect to a preferred embodiment, it would be apparent to one skilled in the art to practice the present invention with other configurations of information retrieval systems. Such alternate embodiments would not cause departure from the spirit and scope of the present invention.
APPENDIX A.
GRAMMAR FOR THE USAGE RIGHTS LANGUAGE
work-specification −>
(Work:
(Rights-Language-Version: version-id)
(Work-I D: work-id) opt
(Description: text-description) opt
(Owner: certificate-spec) opt
(Parts: parts-list) opt
(Contents: (From: address) (To: address)) opt
(Copies: copy-count) opt
(Comment: comment-str) opt
rights-group-list )
parts-list −> work-id | work-id parts-list
copy-count −> integer-constant | unlimited
rights-group-list −>
rights-group-spec rights-group-list opt
rights-group-spec −>
( rights-group-header rights-group-name
bundle-spec opt
comment opt
rights-list)
rights-group-header −>
Rights-Group: |
Reference-Rights-Group:
bundle-spec −>
(Bundle: comment opt time-spec opt access-spec opt
fee-spec opt watermark-spec opt )
comment −> (Comment: comment-str)
rights-list −> right rights-list opt
right −> (right-code comment opt time-spec opt access-spec opt fee-spec opt )
right-code −>
transport-code |
render-code |
derivative-work-code |
file-management-code |
configuration-code
transport-code −> transport-op-spec next-copy-dghts-spec opt :
transport-op-spec −>
Copy: |
Transfer: |
Loan: remaining-rights-spec opt
next-copy-rights-spec −> (Next-Copy-Rights: next-set-of-rights )
remaining-rights-spec −> (Remaining-Rights: rights-groups-list)
next-set-of-rights −> rights-to-add-spec opt | rights-to-delete-spec opt
rights-to-add-spec −> (Add: rights-groups-list )
rights-to-delete-spec −> (Delete: rights-groups-list )
render-code −>
Play: player-spec opt |
Print: Printer-spec opt |
Export: repository-spec opt
player-spec −> (Player: certificate-list) opt (Watermark: watermark-spec) opt
printer-spec −> (Printer: certificate-list ) opt (Watermark: watermark-spec) opt
repository-spec −> (Repository: certificate-list) opt
derivative-work-code −>
derivative-op-spec editor-spec opt next-copy-rights-spec opt
derivative-op-spec −>
Edit: |
Extract: |
Embed:
editor-spec −> (Editor: certificate-list)
file-management-code −>
Backup: backup-copy-rights-spec opt |
Restore: |
Verify: verifier-spec opt |
Folder: |
Directory: |
Delete:
backup-copy-rights-spec −> Backup-Copy-Rights: rights-groups-list
verifier-spec −> (Verifier: certificate-list)
configuration-code −>
Install: |
Uninstall:
time-spec −>
(Time: interval-type expiration-spec opt )
interval-type −>
fixed-interval-spec |
sliding-interval-spec |
metered-interval-spec
fixed-interval-spec −> (From: moment-spec)
sliding-interval-spec −> (Interval: interval-spec)
metered-interval-spec −> (Metered: interval-spec)
expiration-spec −> (Until: moment-spec)
moment-spec −> date-constant time-of-day-constant opt
interval-spec −>
calendar-units-constant |
time-units-constant |
calendar-units-constant time-units-constant
fee-spec −> (Fee: ticket-spec | monetary-spec
ticket-spec −> (Ticket: (Authority: authority-id) (Type: ticket-id ))
monetary-spec −>
(fee-type min-price-spec opt max-price-spec opt account-spec )
fee-type −>
(Per-Use: money-units )|
(Metered: (Rate: money-units)
(Per: interval-spec ) (By: interval-spec) opt |
(Best-Price-Under: money-units )|
(Call-For-Price: dealer-id )|
(Markup: percentage )
money-units −> floating-constant (Currency: ISO-Currency-Code ) opt
account-spec −> (To: account-id ) (House: clearing-house-id) opt |
(From: account-id) (House: cleadng-house-id) opt
min-price-spec −> (Min: (Rate: money-units ) (Per: interval-spec))
max-price-spec −> (Max: (Rate: money-units ) (Per: interval-spec))
access-spec −>
(Access: security-class-spec opt
user -spec opt
source-spec opt
destination-spec opt )
-class-spec −> (Security: s-list)
s-list −> s-pair | s-pair s-list
s-pair −> (s-name: s-value)
s-name −> literal-constant
s-value −> floating-constant
user-spec −> (User: authorization-spec)
source-spec −> (Source: authorization-spec)
destination-spec −>
(Destination: authorization-spec)
authorization-spec −>
(Any: certificate-list ) |
certificate-list
certificate-list −> certificate-spec certificate-list opt
certificate-spec −> (Certificate: (Authority: authority-id) property-list opt )
property-list −> property-pair | property-pair property-list
property-pair −> (property-name: property-value)
property-name −> literal-constant
property-value −> string-constant | literal-constant
| floating-constant | integer-constant
watermark-spec −> watermark-info-list
watermark-info-list −> watermark-str-spec opt watermark-info-list opt |
watermark-token-spec opt watermark-info-list opt |
watermark-object-spec opt watermark-info-list opt
watermark-str-spec −> (Watermark-Str: watermark-str)
watermark-token-spec −> (Watermark-Tokens: watermark-tokens)
watermark-tokens −> watermark-token watermark-tokens opt
watermark-token −> all-rights | render-rights |
user-name | user-id | user-location |
institution-name | institution-id | institution-location |
render-name | render-id | render-location | render-time
watermark-object-spec −> (Watermark-Object: work-id)
|
A trusted rendering system for use in a system for controlling the distribution and use of digital works. A trusted rendering system facilitates the protection of rendered digital works which have been rendered on a system which controls the distribution and use of digital works through the use of dynamically generated watermark information that is embedded in the rendered output. The watermark data typically provides information relating to the owner of the digital work, the rights associated with the rendered copy of the digital work and when and where the digital work was rendered. This information will typically aid in deterring or preventing unauthorized copying of the rendered work to be made. The system for controlling distribution and use of digital works provides for attaching persistent usage rights to a digital work. Digital works are transferred between repositories which are used to request and grant access to digital works. Such repositories are also coupled to credit servers which provide for payment of any fees incurred as a result of accessing a digital work.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a complete utility application entitled to the priority and claiming the benefit of U.S. provisional application Ser. No. 60/378,660, filed May 9, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an underwater pelletizer and more specifically to a cutter hub and blade assembly supported and driven for rotational movement and axial movement in relation to the die face of a die plate in an underwater pelletizer. The supporting and driving arrangement for the cutter hub and blades includes a positive control of axial movement of the cutter hub and blades in relation to the die face as the cutter hub and blades are moved toward and away from the die face to obtain and maintain axial adjusted positions of the cutter hub and blades to minimize wear on the mechanical components involved. Positive control of the axial movement of the cutter hub and blades is obtained by a hydraulic/pneumatic actuation system controlling a motion rod extending through a driven hollow motor shaft with one end of the motion rod connected with a hydraulic/pneumatic control and the other end being rigidly connected to a cutter hub holder that supports the cutter hub and blades to move the cutter hub and blades toward and away from the die face.
2. Description of the Prior Art
Underwater pelletizers including a cutter hub holder supporting a cutter hub and blades associated with a die face in order to rotate the blades to cut strands of extruded polymer into pellets within a water box through which water is circulated to cool and harden the pellets and convey a slurry of pellets to an outlet in the water box are well known. Prior U.S. Pat. No. 6,332,765 issued Dec. 25, 2001 for Cutter Hub Holder discloses a cutter hub holder, cutter hub and blades biased toward the die plate by variable pressure through a resilient structure incorporated into supporting and driving engagement with the cutter hub and blades. The present invention comprises an improvement over the cutter hub holder disclosed in aforesaid U.S. Pat. No. 6,332,765 which, together with the prior art of record therein are incorporated herein by reference as if fully set forth herein.
In U.S. Pat. No. 6,332,765, the cutter hub holder is connected to and supports the cutter hub and blades and is drivingly connected to a motor shaft. The motor shaft extends through an electric motor and is hollow throughout its length. One end of the motor shaft is communicated with a stationary rotary transmission lead that is communicated with a source of fluid pressure through a pressure regulating valve. The hollow motor shaft includes a piston and piston rod moveable in the interior of the hollow motor shaft which defines a cylinder for the piston to move the piston and piston rod axially in relation to the motor shaft. The piston rod is connected to a cutter hub holder through a resilient device, such as a spring, to bias the cutter hub holder, cutter hub and blades thereon toward the die face. This structure provides an axial force to move the cutter hub and blades toward the die plate but does not provide any force to move the cutter hub and blades axially away from the die face. Further the prior art does not provide a mechanism for positively controlling the movement of the cutter hub and blades toward and away from the die plate.
SUMMARY OF THE INVENTION
This invention provides a positive control of the positions of a cutter hub and blades in relation to a face of an underwater pelletizer.
It is an object of the present invention to provide a control mechanism in which axial movement of the cutter hub and blades in relation to the die face is positively controlled in both directions of cutter blade adjustment axially in relation to the die face of a die plate in an underwater pelletizer.
Another object of the present invention is to provide a positive control of the relationship between the cutter hub and blades and the die face in an underwater pelletizer in which positive control of movement in both directions is provided by a hydraulic/pneumatic actuation system mechanically connected to the cutter hub through an elongated motion rod fixedly connected to the cutter hub holder that supports the cutter hub.
A further object of the present invention is to provide a positive control for the cutter hub and blades in accordance with the preceding object in which the motion rod connected to the cutter hub holder extends through a hollow motor shaft and rotatably connects to the piston rod of a double acting hydraulic actuated piston and cylinder assembly on the opposite side of the motor from the cutter hub and blades. The piston and cylinder assembly are associated with an air-oil pressure system that controls a closed hydraulic circuit that functions to move the motion rod, cutter hub, cutter hub holder and cutter blades in a positively controlled manner due to the incompressibility of the hydraulic fluid associated with the piston and cylinder and the economical use of air pressure directly on the closed hydraulic circuit. Lock positions of the motion rod, cutter hub holder, cutter hub and blades is obtained by a blocking valve positioned within the fluid circuits.
A still further object of the present invention is to provide a positively controlled cutter hub for effectively controlling movement of the cutter hub and blades in both directions in relation to the die face of a die plate in an underwater pelletizer in which the structure enables assembly and disassembly of the cutter hub and cutter hub holder, the drive structure for the cutter hub holder and the elongated motion rod connected to the cutter hub holder at one end and rotatably connected to the piston in the hydraulic cylinder in closed hydraulic circuit at its other end, with the hollow shaft guidingly supporting said motion rod during its axial movement.
Still another object of the present invention is to provide a positive control axial movement of the blades of an underwater pelletizer in accordance with the preceding objects in which the motion rod connected to the pelletizer blade hub holder is moved axially forward toward the die face as well as axially backwards away from the die face and rotates with the hollow motor shaft of the pelletizer motor in order to isolate any torsional forces created by operation of the motor during pellet cutting. This assembly eliminates the need for a cylindrical or barrel piston, piston rod and spring assembly in the motor shaft, thus reducing the number of mechanical components and providing direct mechanical connection between the motion rod and the cutter hub holder, cutter hub and cutter blades.
Yet another object of the present invention is to provide a positive control for the cutter hub and blades of an underwater pelletizer in which the closed circuit hydraulic double acting cylinder and piston connected to the motion rod has both ends of the cylinder connected to an air-oil actuator through independent stop valves which serve to hold the pelletizing blades in their position once operating pressure has been reached so as to insure a uniform pellet shape. Each air-oil actuator is communicated with a source of air pressure through a proportional valve. The air pressure is translated to a hydraulic fluid pressure in the air-oil actuator for positively controlling movement and position of the piston in the hydraulic cylinder. The piston rod extending from the piston is directly connected to the rotatably driven motion rod which in turn is directly connected to the cutter hub holder, cutter hub and cutter blades all of which are moved axially in both axial directions in unison with the piston in the double acting hydraulic cylinder.
Yet a further object of the present invention is to provide a positive control for a cutter hub and cutter blades in an underwater pelletizer for movement in both axial directions in relation to a die face by utilizing the elongated motion rod extending through the hollow motor shaft and rotatably connected to a piston of a double acting hydraulic cylinder at an end of the rod opposite to the cutter hub and blades with the end of the motion rod adjacent the cutter hub being threadedly engaged with the cutter hub holder which is threadedly engaged with the cutter hub to enable easy assembly and disassembly of the components. A lock screw is preferably threaded into the cutter hub holder and engaged with the threaded end of the motion rod to lock the cutter hub holder in nonrotative relation to the motion rod to assure continuous engagement between the motion rod and cutter hub holder but yet enabling easy disassembly by removing the lock screw and threadedly uncoupling the cutter hub holder from the motion rod.
An additional object of this invention to be specifically enumerated herein is to provide an underwater pelletizer with positively controlled cutter hub in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.
These together with other objects and advantages which will become subsequently apparent reside in the details of construct 8 on and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numeral refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an underwater pelletizer, partly in section, illustrating the structural details and relationships of the components of the positive control of the cutter hub and cutter blades in accordance with the present invention.
FIG. 2 is a perspective view, partly in section, illustrating the cutter hub holder drivingly connected to the motor shaft and the motion rod extending through the cutter hub holder with the end of the motion rod threadedly engaged with the interior of the end of the cutter hub holder that is threaded into the cutter hub, in accordance with the present invention.
FIG. 3 is a partially exploded perspective view illustrating the relationship of the cutter hub holder, cutter hub with blades and a lock screw that threadedly engages the internal threads in the cutter hub holder and locks the motion rod against rotation in relation to the cutter hub by contact with the end of the motion rod, in accordance with the present invention.
FIG. 4 is an exploded group perspective view, with portions in section, illustrating further association of the motor shaft, pelletizer shaft, the driving connection between the shafts, the motion rod and the relationship to the cutter hub holder and cutter hub with the lock screw positioned for threaded engagement with the end of the cutter hub holder in accordance with the present invention.
FIG. 5 is a perspective view partially in section illustrating the spline structure of the cutter hub holder and the relationship between the lock screw, the cutter hub holder and the end of the motion rod in accordance with the present invention.
FIG. 6 is a schematic elevational view of the double acting hydraulic cylinder and piston illustrating fluid pressure on the piston in both axial directions in accordance with the present invention.
FIG. 7 is a schematic diagram of the closed hydraulic fluid circuit and the pneumatic circuit for controlling flow in the hydraulic circuit in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although only one preferred embodiment of the invention is explained in detail, it is to be understood that the embodiment is given by way of illustration only. It is not intended that the invention be limited in its scope to the details of constructions and arrangement of components set forth in the following description or illustrated in the drawings. Also, in describing the preferred embodiment, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
An underwater pelletizer constructed in accordance with the present invention is generally designated by reference numeral 10 in FIG. 1 . The pelletizer 10 includes a rotatable cutter hub 12 supporting a plurality of cutter blades 14 associated with the die face of a die plate 16 through which molten polymer or other extrudable material is extruded through extrusion orifices in the die plate, and the cutter blades 14 cut the strands exiting the die face into pellets. A water box generally designated by reference numeral 20 includes an interior 22 having a water inlet 24 and a water and pellet slurry outlet 26 in opposed relation thereto. Water passing through the water box interior 22 cools and solidifies the molten plastic or extrudate as the strands are cut into pellets and entrains the pellets into the water flow for discharge through the outlet 26 . The above described structure is a conventional underwater pelletizer such as that disclosed in U.S. Pat. No. 6,332,765. The water box 20 includes a tapered flange 28 abutingly engaging a flange 30 mounted on the end of a motor 50 by fastening bolts 32 . The flanges 28 and 30 have oppositely slanted peripheral edge portions for engagement by a two part channel shaped clamp 34 to enable assembly and disassembly of the water box in relation to the motor mounted flange 30 in a conventional manner.
As illustrated in FIG. 3 , the cutter hub 12 includes a centrally disposed internally threaded opening 38 which screw threadably receives a male threaded, reduced diameter end portion 40 of a cutter hub holder 42 . As illustrated in FIG. 2 , the cutter hub holder 42 is slidingly and drivingly connected to an intermediary 44 by a slidable spline drive connection 46 in the form of longitudinal grooves and ridges in a manner similar to that disclosed in U.S. Pat. No. 6,332,765. The intermediary 44 includes a longitudinal recess 47 of larger diameter than the portion of intermediary which engages with the cutter hub holder 42 for receiving a motor shaft 48 which extends through the center of the electric drive motor 50 . The intermediary 44 is drivingly connected to the motor shaft 48 by set screws 52 or similar fastening devices. The structure of the motor shaft 48 , intermediary 44 and cutter hub holder 42 are the same as disclosed in the aforesaid U.S. Pat. No. 6,332,765.
As illustrated in FIGS. 2–4 , the motor shaft 48 is hollow and includes an elongated one piece motion rod 54 extending completely through the motor shaft 48 and the motor 50 . The motion rod 54 includes a reduced diameter threaded end 56 which is screw threadedly engaged with an internally threaded end portion 58 of the cutter hub holder 42 . The reduced end 56 of motion shaft 54 has a screw driver receiving kerf 57 therein to enable assembly and disassembly of motion rod 54 and cutter hub holder 42 . The reduced threaded end 56 on rod 54 defines a shoulder 60 which abuts an inner shoulder 62 at the inner end of the internally threaded portion 58 of the end of the cutter hub holder to thereby screw threadedly connect the threaded end 56 of the motion rod 54 to the interior of the cutter hub holder 42 . A lock screw 64 is threaded into the internally threaded end portion 58 of the cutter hub holder 42 into abutting engagement with the end of the motion rod 54 to provide a locking action between the external threads on the motion rod 54 and the internal threads 58 in the end of the cutter hub holder 42 . The holder 42 is threaded into the cutter hub 12 by external threads 40 engaging the internal threads 38 in the cutter hub 12 .
The spline coupling 46 enables the cutter hub holder 42 to elongate or shorten as determined by movement of the motion rod 54 . The lock screw 64 enable assembly and disassembly of the cutter hub holder 42 from the motion rod 54 and locks the cutter hub holder and cutter hub fixedly but detachably to the motion rod 54 .
Turning back to FIG. 1 , the motor 50 includes a housing extension 66 which is supported from the motor 50 by elongated bolts 68 . Housing extension 66 is closed at its remote end by an end plate that supports a double acting hydraulic cylinder 72 outwardly thereof, preferably within a rear enclosure 74 . The motion rod 54 which extends through the motor drive shaft 48 is provided with a rotary coupling 76 in the interior of the housing extension 66 . A bracket 77 supports the coupling 76 and a thrust bearing 78 . The hydraulic cylinder 72 includes a piston 83 and piston rod 84 connected with the coupling 76 to rotatably connect the motion rod 54 to non-rotatable piston rod 84 . FIG. 7 illustrates the function of the double acting hydraulic cylinder 72 to transmit forward or backward motion forces to the piston 83 , and through piston rod 84 and thrust bearing 78 , to motion rod 54 and thus to the pelletizer cutter hub and blades.
More specifically, the double acting motion cylinder 72 generates the pressure for advancing or withdrawing the blades as triggered by the control system illustrated in FIG. 7 . The control system provides hydraulic fluid pressure that is incompressible to the cylinder 72 on opposite sides of the piston 83 as shown in FIG. 6 to move the piston rod 84 and thus the motion rod 54 in opposite directions, moving the cutter hub and blades either towards or away from the die face. Hydraulic fluid is supplied to opposite ends of the cylinder 72 by hydraulic fluid pressure lines 85 and 86 each of which includes a pressure gauge 88 . The hydraulic line 84 provides for forward motion of the piston 83 and motion rod 54 , and the hydraulic line 86 provides backward motion of the piston 83 and motion rod 54 . Each of the hydraulic lines 85 and 86 is also provided with a stop valve 90 which is connected to one end of an air-oil actuator 92 which includes a cylinder 94 having the fluid pressure lines 85 and 86 connected to one end of the cylinder 94 and an air supply line 96 connected to an outer end of a cylinder 94 . Each air supply line 96 is provided with a proportional valve 98 communicated with an air supply 100 through a pressure amplifier or amplifiers 102 depending upon the air pressure supply.
The air-oil system includes two pressure circuits that can be controlled independently from one another including a blade forward pressure circuit and a blade back pressure circuit. In the blade forward pressure circuit the pelletizing pressure is controlled by a proportional valve to automatically insure the optimum pelletizing pressure in each operating phase. The generated pneumatic blade forward pressure is translated into a fluid pressure in an air-oil actuator and this incompressible fluid pressure then acts on the piston side of the double acting cylinder to move the blade forward or toward the die plate.
The blade back pressure circuit provides a backward motion or pressure which is also set by a proportional valve and translated into a fluid pressure in an air-oil actuator to act on the side of the piston to move the blades backwards or away from the die plate. Thus, the two variables providing fluid pressure on opposite sides of the piston insures an optimum positioning of the pelletizer blades and avoiding any unnecessary blade wear. The stop valves in the control circuits serve to hold the pelletizing blades in their position after start up of the pelletizer and proper operating pressure has been reached so as to insure a uniform pellet shape.
The positive controlled movement of the cutter hub and blades enables control of the forces acting on the blades and the die plate in all operating stages to reduce wear of the pelletizing blades and die face. The double acting motion cylinder 72 generates pressure for advancing or withdrawing the blades with the pressure being transmitted to the cutter hub holder and thus to the cutter hub blades by the motion rod 54 which is fixed to the cutter hub holder and passes through and rotates with the hollow motor shaft.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A cutter hub and blade assembly supported and driven for rotational and axial movement in relation to the die face of a die plate in an underwater pelletizer including a positive control of such axial movement to obtain and maintain optimal axial position of the cutter hub and blades during the pelletizing operation and to minimize wear of the mechanical components involved. Positive control of the axial movement of the cutter hub and blades is obtained by a hydraulic/pneumatic actuation system controlling an elongated motion rod that extends through a driven hollow motor shaft. One end of the motion rod is connected with a hydraulic/pneumatic control and the other end of the rod is connected to a cutter hub holder that supports the cutter hub and blades for axial movement toward or away from the die face.
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This application is a divisional patent application under 37 C.F.R. §1.53(b) of commonly owned U.S. patent application Ser. No. 11/361,840 to Robert Thaihammer, et al. and filed on Feb. 24, 2006. Priority to U.S. patent application Ser. No. 11/361,840 is hereby claimed under 35 U.S.C. §121. The entire disclosure of U.S. patent application Ser. No. 11/361,840 is specifically incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of piezoelectric resonators, e.g. BAW (bulk acoustic wave) resonators, and particularly to a method of manufacturing an acoustic mirror for a piezoelectric resonator, as well as to a method of manufacturing a piezoelectric resonator. In particular, the present invention relates to a method of manufacturing an acoustic mirror, which is highly planar and has both excellent uniformity in the layer deposition and a planar surface of the entire mirror structure.
2. Description of the Related Art
Radio-frequency filters based on BAW resonators are of great interest for many RF applications. Substantially, there are two concepts for BAW resonators, so-called thin film BAW resonators (FBAR), on the one hand, as well as so-called solidly mounted resonators (SMR). Thin film BAW resonators include a membrane on which the layer sequence consisting of the lower electrode, the piezoelectric layer, and the upper electrode is arranged. The acoustic resonator develops by the reflection at the upper side and at the lower side of the membrane. In the alternative concept of solidly mounted resonators, an SMR includes a substrate, for example a silicon substrate, on which the layer sequence consisting of the lower electrode, the piezoelectric layer, and the upper electrode is arranged. So as to keep the acoustic waves in the active region in this design, a so-called acoustic mirror is required. It is located between the active layers, i.e. the two electrodes and the piezoelectric layer, and the substrate. The acoustic mirror consists of an alternating sequence of layers with high and low acoustic impedance, respectively, e.g. layers of tungsten (high acoustic impedance) and layers of oxide material (low acoustic impedance).
If the mirror contains layers of conducting materials, such as tungsten, it is recommended, for the avoidance of parasitic capacitances in the filter, to structure (pattern) and substantially limit the corresponding mirror layers to the area below the active resonator region. The disadvantage of this procedure is that the topology resulting hereby can no longer be completely planarized. Due to the unevenness, undesired modes are induced in the resonator and/or a reduction in the quality of the resonator is caused. This problem is very critical in so far as already small steps or remaining topologies of several percent of the layer thickness have significant influence on the operation behavior of such a resonator.
On the basis of FIGS. 1 and 2 , two known methods of manufacturing acoustic mirrors for piezoelectric resonators or BAW resonators are explained in greater detail.
FIG. 1 shows a solidly mounted resonator with structured mirror. The resonator includes a substrate 100 with a lower surface 102 and an upper surface 104 . A layer sequence 106 forming the acoustic mirror is arranged on the upper surface. Between the substrate and the mirror, one or more intermediate layers serving for stress reduction or adhesion improvement may be arranged, for example. The layer sequence includes alternately arranged layers 106 a with high acoustic impedance and layers 106 b with low acoustic impedance, wherein intermediate layers may be provided between the mirror layers. On the upper surface 104 of the substrate 100 , a first layer 106 b 1 with low acoustic impedance is formed. On the layer 106 b 1 , a material 106 a 1 , 106 a 2 with high acoustic impedance is deposited and structured at the portions associated with the active regions of the resonator. Over this arrangement, a second layer 106 b 2 with low acoustic impedance is deposited, upon which in turn a material 106 a 3 , 106 a 4 with high acoustic impedance is deposited and structured section-wise. Upon this layer sequence, again a layer with low acoustic impedance 106 b 3 is deposited. On the resulting mirror structure, a lower electrode 110 , on which again the active or piezoelectric layer 112 , for example of AlN, is arranged, is at least partially formed. On the piezoelectric layer 112 , an insulation layer 114 covering the piezoelectric layer 112 except for the regions 116 a and 116 b is formed. Two upper electrodes 118 a and 118 b in contact with the piezoelectric layer in the portions 116 a and 116 b are formed on the piezoelectric layer. A tuning layer 120 a and 120 b , via the thickness of which a resonance frequency of the resonators can be adjusted, is at least partially arranged on the upper electrode 118 a , 118 b . By the portions of the upper electrode 118 a and 118 b in which it is in connection with the piezoelectric layer 112 , and the underlying portions of the lower electrode 110 , two BAW resonators 122 a and 122 b are defined. The mirror structure 106 shown in FIG. 1 includes λ/4 mirror layers 106 a , 106 b.
In the example of a solidly mounted resonator shown in FIG. 1 , as it is produced by Epcos AG, for example, the metallic layers 106 a are structured without planarizing the resulting topology. The layers 106 b with low acoustic impedance are deposited over the structured layers 106 a , as described above. Thereby, the steps shown in FIG. 1 , which continue in the deposition of the overlaying layers, develop. This procedure is disadvantageous regarding the resulting strong topology in the layers lying above the mirror 106 , in particular, with reduced piezoelectric coupling of the active layer 112 as well as increased excitation of undesired vibrational modes arising.
FIG. 2 shows a further example known in the prior art for solidly mounted resonators with a structured mirror. In FIG. 2 , again a substrate 100 is shown, on the upper surface 104 of which an oxide layer 124 is deposited, into which a pit or depression 126 is introduced. Further intermediate layers may be provided between the oxide layer 124 and the substrate 100 . In the pit 126 , the acoustic mirror is formed, which consists of a layer sequence comprising a first layer 106 a 1 with high acoustic impedance, a layer 106 b with low acoustic impedance, and a layer 106 a 2 with high acoustic impedance. On the surface of the resulting structure, an insulation layer 108 is deposited, on which the lower electrode 110 is at least partially formed. The portion of the insulation layer 108 not covered by the lower electrode 110 is covered by a further insulation layer 128 . On the insulation layer 128 and on the lower electrode 110 , the piezoelectric layer 112 is formed, on the surface of which the upper electrode 118 is in turn partially formed. The portions of the piezoelectric layer 112 not covered by the upper electrode 118 , as well as parts of the upper electrode 118 are covered by the passivation layer 114 . The overlapping areas of lower electrode 110 , piezoelectric layer 112 , and upper electrode 118 define the BAW resonator 122 .
In the example shown in FIG. 2 , the pit 126 , in which the mirror layers 106 a , 106 b are deposited after each other, as described above, is etched into the oxide layer 124 in the area of the resonator 122 to be produced. By one or more CMP (chemical mechanical polishing) processes, the layers outside the mirror pit 126 are removed, as this is described in the U.S. patent application US 2002/154425 A1, for example.
The method described on the basis of FIG. 2 is disadvantageous in that the layers are slightly thinner in the corners of the mirror pit 126 , and a slight key topology in the resonator region 122 , indicated with the reference numeral 130 , develops, which again leads to increased excitation of undesired modes and to reduced resonator quality.
SUMMARY OF THE INVENTION
Starting from this prior art, it is an object of the present invention to provide an improved method of manufacturing an acoustic mirror for a piezoelectric resonator, which enables mirrors with excellent uniformity in the layer deposition, as well as a planar surface of the entire mirror structure.
In accordance with a first aspect, the present invention provides a method of manufacturing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has a layer sequence of at least one layer with high acoustic impedance and at least one layer with low acoustic impedance, with the steps of: (a) producing a first layer of the layer sequence; (b) producing a second layer of the layer sequence on the first layer, such that the second layer partially covers the first layer; (c) applying a planarization layer on the first layer and on the second layer; (d) exposing a portion of the second layer by structuring the planarization layer, wherein the portion of the second layer is associated with an active region of the piezoelectric resonator; and (e) planarizing the structure from step (d) by removing the portions of the planarization layer remaining outside the portion.
In accordance with a second aspect, the present invention provides a method of manufacturing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has an alternating layer sequence of a plurality of layers with high acoustic impedance and a plurality of layers with low acoustic impedance, with the steps of: (a) alternately producing the first layers and the second layers; (b) applying a planarization layer on the structure produced in step (a); (c) exposing a portion of the topmost second layer by structuring the planarization layer, wherein the portion of the topmost second layer is associated with an active region of the piezoelectric resonator; and (d) planarizing the structure from step (c) by removing the portions of the planarization layer remaining outside the portion.
In accordance with a third aspect, the present invention provides a method of manufacturing a piezoelectric resonator, with the steps of: (a) producing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has a layer sequence of at least one layer with high acoustic impedance and at least one layer with low acoustic impedance, with the steps of: (a.1) producing a first layer of the layer sequence; (a.2) producing a second layer of the layer sequence on the first layer, such that the second layer partially covers the first layer; (a.3) applying a planarization layer on the first layer and on the second layer; (a.4) exposing a portion of the second layer by structuring the planarization layer, wherein the portion of the second layer is associated with an active region of the piezoelectric resonator; and (a.5) planarizing the structure from step (a.4) by removing the portions of the planarization layer remaining outside the portion; (b) producing a lower electrode substantially at least partially on the acoustic mirror; (c) producing a piezoelectric layer at least partially on the lower electrode; (d) producing an upper electrode at least partially on the piezoelectric layer, wherein a region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines an active region of the piezoelectric resonator.
In accordance with a fourth aspect, the present invention provides a method of manufacturing a piezoelectric resonator, with the steps of: (a) producing an acoustic mirror of alternately arranged layers of high and low acoustic impedance, preferably for an acoustic resonator, wherein the mirror has an alternating layer sequence of a plurality of layers with high acoustic impedance and a plurality of layers with low acoustic impedance, with the steps of: (a.1) alternately producing the first layers and the second layers; (a.2) applying a planarization layer on the structure produced in step (a.1); (a.3) exposing a portion of the topmost second layer by structuring the planarization layer, wherein the portion of the topmost second layer is associated with an active region of the piezoelectric resonator; and (a.4) planarizing the structure from step (a.3) by removing the portions of the planarization layer remaining outside the portion; (b) producing a lower electrode substantially at least partially on the acoustic mirror; (c) producing a piezoelectric layer at least partially on the lower electrode; (d) producing an upper electrode at least partially on the piezoelectric layer, wherein a region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines an active region of the piezoelectric resonator.
The inventive method enables the manufacture of a highly planar acoustic mirror and produces a mirror ensuring both excellent uniformity in the layer deposition and a planar surface of the entire mirror structure. Thus, according to the invention, optimum deposition of the layers lying above the mirror is enabled, which particularly results in high coupling of the piezoelectric layer. Furthermore, according to the invention, also a very homogenous layer distribution in the mirror is achieved, which again leads go high quality of the resonator and to minimum excitation of undesired vibrational modes.
According to the invention, the acoustic mirror is manufactured by a novel combination of depositing, structuring (patterning), and planarizing steps. According to the invention, for this, one or more layers of the mirror are structured, then a planarization layer is deposited on the whole area and opened by an etching process in the resonator region. The resonator region is that region of the mirror associated with the active region of the piezoelectric resonator, wherein the region to be opened is usually selected greater than the active resonator region actually resulting later, due to the adjustment tolerances and due to not exactly perpendicular etching flanks. Then, according to the invention, only the ridges remaining in the overlapping region are removed by a planarization process, for example by a CMP method, wherein the above-described steps are repeated several times depending on the number of the layers to be realized in the acoustic mirror, according to a preferred embodiment of the present invention.
According to the invention, for opening the planarization layer in the critical region, an etching process is thus used, which is selective with reference to the material of the topmost layer of the mirror structure, i.e. this topmost layer serving as etch stop layer. According to the invention, it is thus taken advantage of the fact that such etching processes largely conserve the topology developed in the deposition, whereby the inventive, highly planar, acoustic mirror structure is securely achieved in the critical region of a BAW resonator or piezoelectric resonator.
The highly planar shape of the mirror does not only result from the etching procedure. As mentioned above, a non-planar topology results already in the deposition in the method according to FIG. 2 , because the deposition rate in the corners of the mirror pitch is different than at the center. Moreover, a slight key topology is produced at the center when mechanically polishing. It is the substantial point of the present invention that all depositions take place on planar foundation (and thus no topology develops in the deposition), wherein the planarization steps are chosen so that they do not produce substantial topology in the layers in the resonator region.
Preferably, the second layer to be structured is a conductive layer. The layers for the mirror described in connection with the present invention may be divided into either conductive/non-conductive or non-insulating/insulating layers, or into layers with low or high acoustic impedance. Due to parasitic electrical couplings, when using conductive layers, these are structured independently of whether they have the higher or the lower acoustic impedance. Semiconducting layers may also be used.
According to a first preferred embodiment of the present invention, the layer with high acoustic impedance is a conductive layer, and a structuring step and planarization step of its own is performed for each conductive layer of the mirror structure. In case of a mirror with two conductive layers, at first all layers up to the first conductive layer are deposited. Then, this is structured and planarized, and then all layers up to the second conductive layer are deposited and again structured and planarized ( FIG. 3 ).
In a second embodiment of the present invention, at first all layers of the mirror are deposited and the conductive layers structured and planarized together with non-conductive layers lying therebetween. As opposed to the first preferred embodiment, here the advantage is that only two lithography steps are required, independent of the number of conductive layers. The first embodiment, however, requires two lithography steps each for every conductive layer to be structured and planarized. But the etching process is more intensive, and the planarization is more difficult due to the higher step.
In addition, an etch stop layer may be deposited below the conductive layers, so that the homogeneity/reproducibility of the etch stop may be improved with a selective etching process.
Preferably, the etching processes are performed using a resist mask or using a hard mask, wherein in the second embodiment the use of a hard mask may be necessary due to the longer etching time.
In the above-described embodiment, the plurality of layers may be performed either in an etching process within one chamber or by several successive etching processes in various chambers.
In the above-described first embodiment, in which every conducting layer is structured and planarized separately, the same or different masks may be used to produce substantially equally or differently large layers with this. In the latter case, a mirror structure of truncated cone shape or truncated pyramid shape may be produced, for example.
According to a further embodiment, the present invention provides a method of manufacturing a piezoelectric resonator, wherein at first an acoustic mirror according to the present invention is produced, and then a lower electrode is produced on the acoustic mirror. A piezoelectric layer, on the upper surface of which an upper electrode is at least partially produced, is at least partially produced on the lower electrode. The region in which the upper electrode, the piezoelectric layer, and the lower electrode overlap, defines the active region of the piezoelectric resonator. Furthermore, it may be provided that, prior to producing the lower electrode, one or more layers with suitable acoustic impedance are applied on the produced acoustic mirror, wherein the lower electrode is produced on these layers. In particular, these layers serve for insulation, when the topmost layer in the mirror structure is a conductive layer, or for adjusting certain acoustic properties, such as the dispersion properties of the layer stack, the resonance frequencies of further modes (shear wave modes), or the temperature course. One layer or a plurality of layers of different materials and with different layer thicknesses may be provided.
Furthermore, the present invention provides a method of manufacturing coupled acoustic resonators. Such resonators are arranged vertically on top of each other, i.e. the active part of the resonator (lower electrode, piezoelectric layer, upper electrode) is present twice, separated by one or more intermediate layers, via which the strength of the acoustic coupling may be adjusted. The entire layer stack is placed on the acoustic mirror, like with the individual resonators.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become clear from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a first example of a solidly mounted resonator with structured mirror according to the prior art;
FIG. 2 shows a second example of a solidly mounted resonator with structured mirror according to the prior art;
FIGS. 3( a ) to ( g ) show the steps for manufacturing a highly planar acoustic mirror according to the present invention;
FIGS. 4( a ) to ( j ) show the inventive processing of an acoustic mirror with two conductive layers by multiple depositing, structuring, and planarizing steps according to a first preferred embodiment; and
FIGS. 5( a ) to ( e ) show the inventive processing of an acoustic mirror with two conductive layers by common structuring and planarization of all mirror layers according to a second preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the subsequent description of the preferred embodiments of the present invention, the same or similarly acting elements are provided with the same reference numerals.
In the subsequent explanations, it is assumed that the layer to be structured has the higher acoustic impedance. The present invention is not limited to this embodiment, the inventive method rather works in fully analog manner when the conductive layer has the smaller acoustic impedance.
On the basis of FIG. 3 , the concept underlying the present invention will be explained in greater detail. In FIG. 3( a ), a substrate 100 is shown, on the upper surface 104 of which a first layer 106 b 1 with low acoustic impedance, e.g. an oxide, is arranged, on which in turn a first layer 106 a 1 with high acoustic impedance, e.g. a tungsten layer or another suitable conductive layer, has been deposited on the whole area. In addition, as it has been described above, one or more intermediate layers may be provided between the substrate and the mirror or between the mirror layers. Using a hard mask or a resist mask, the structure shown in FIG. 3( a ) is subjected to a structuring process by which the first conductive layer 106 a 1 with high acoustic impedance is structured to the shape shown in FIG. 3( b ).
On the structure shown in FIG. 3( b ), then a planarization layer 132 is deposited on the whole area, as this is shown in FIG. 3( c ). The planarization layer 132 is structured using a suitable mask, for example a resist mask or a hard mask, so as to define the portions of the planarization layer 132 to be removed in a subsequent etching process.
The structure shown in FIG. 3( c ) after the masking and after the etching process is shown in FIG. 3( d ). The planarization layer 132 is removed in the region 134 , such that a surface 136 of the first layer 106 a 1 with high acoustic impedance is exposed, and the ridges 132 a , 132 b of the planarization layer 132 only remain in the peripheral region. The portion 134 includes at least the active region of the piezoelectric resonator with which the mirror to be produced is used, wherein the region 134 is usually chosen slightly greater than the active region of the piezoelectric resonator actually resulting later, due to the adjustment tolerances and the oblique etching flanks.
The structure shown in FIG. 3( d ) is subjected to a planarization process leading to the removal of the ridges 132 a and 132 b , for example by a CMP process. The structure resulting after the planarization is shown in FIG. 3( e ), in which the structure comprises a planar surface, wherein the surface 136 of the first layer 106 a 1 is substantially flush with a surface 138 of the portions of the planarization layer 132 arranged on the first layer 106 b 1 with low acoustic impedance.
Subsequently, the steps illustrated on the basis of FIGS. 3( a ) to 3 ( e ) are repeated, so that the structure shown in FIG. 3( f ) with two layers with high acoustic impedance 106 a 1 and 106 a 2 , as well as with two layers with low acoustic impedance 106 b 1 and 106 b 2 results.
On the structure shown in FIG. 3( f ), one or more layers 140 for insulation, when the topmost layer in the mirror structure is a conductive layer, or for adjusting certain acoustic properties are deposited, as this is shown in FIG. 3( g ). The lower electrode, the piezoelectric layer, as well as the upper electrode may be deposited on this structure, for example, in the manner described on the basis of FIG. 2 for producing a BAW resonator. Furthermore, an intermediate layer may be applied on the resonator, on which a further resonator structure is produced, to produce two coupled resonators.
On the basis of FIG. 4 , a first preferred embodiment of the present invention will be explained in greater detail, namely the inventive processing of an acoustic mirror with two conductive layers by multiple depositing, structuring, and planarizing steps.
The procedural steps shown in FIGS. 4( a ) to 4 ( e ) correspond to the procedural steps described on the basis of FIGS. 3( a ) to ( e ), so that renewed description thereof is omitted. A second layer 106 a 2 with high acoustic impedance, for example again a tungsten layer or another suitable metal layer, is then deposited on the structure shown in FIG. 4( e ) on the whole area, as this is shown in FIG. 4( f ). Using the above-described processes, the layer 106 a 2 is then structured, so that the structure shown in FIG. 4( g ) results. A further planarization layer 132 is then deposited on this structure, as this is shown in FIG. 4( h ). This is again structured, and the portion 134 is opened by means of an etching step, to expose the surface 136 of the layer 106 a 2 .
Again, the ridges 132 a and 132 b remain, as this is shown in FIG. 4( i ). After the planarization of the structure shown in FIG. 4( i ), the structure shown in FIG. 4( j ) with the planar surface results, i.e. a structure in which the surfaces 136 and 138 are substantially flush.
On the basis of FIG. 5 , a second preferred embodiment of the present invention will be explained in greater detail in the following, namely the processing of an acoustic mirror with two conductive layers by common structuring and planarizing of all conductive mirror layers.
In FIG. 5( a ), the substrate 100 , on the upper surface 104 of which the insulation layer 108 is arranged, is shown. In contrast to the previously described embodiments, the layer sequence consisting of a first layer 106 b 1 with low acoustic impedance, a first layer 106 a 1 with high acoustic impedance, a further layer 106 2 with low acoustic impedance, and a further layer 106 a 2 with high acoustic impedance is produced on the surface 104 of the substrate 100 according to the second embodiment of the present invention, as this is shown in FIG. 5( a ).
The structure shown in FIG. 5( a ) is then subjected to a structuring process, wherein the lowest layer 106 b 1 is not structured. By customary masking and etching steps, the layer sequence of the layers 106 a 1 , 106 b 2 , 106 a 2 is given the desired structure, as it is shown in FIG. 5( b ). The planarization layer 132 is deposited over this structure, so that the structure shown in FIG. 5( c ) results. Similar to the preceding embodiments, structuring of the layer 132 now takes place such that an upper surface of the second layer 106 a 2 with high acoustic impedance is exposed, and only the ridges 132 a and 132 b remain, as this is shown in FIG. 5( d ). A subsequent planarization step removes the ridges 132 a and 132 b , so that the structure shown in FIG. 5( e ) results.
A lower electrode, a piezoelectric layer, as well as an upper electrode may be applied on the structure shown in FIG. 5( e ), just like on the structure shown in FIG. 4( j ), in order to complete processing the piezoelectric resonator device, as this has already been explained above on the basis of FIG. 3 .
Although the above-described acoustic mirrors according to the preferred embodiments of the present invention comprise a layer with high acoustic impedance, for example a metal layer, as the topmost layer, the present invention is not limited to such a mirror structure. Rather, by means of the inventive method, also a mirror structure the topmost surface of which is a layer with low acoustic impedance may be produced. Furthermore, tungsten layers were mentioned above as layer with high acoustic impedance, and oxide layers were mentioned as layer with low acoustic impedance.
The present invention is not limited to these materials, but other materials having high acoustic impedance or low acoustic impedance, conductive or non-conductive materials, may be equally employed.
As has been described above, the structured mirror layers may be of variable size, so that a structure of truncated cone of truncated pyramid shape results. In principle, the layout of the resonator/mirror may, however, also have any shape (e.g. a trapezoid), whereby an interesting shape results for the three-dimensional mirror. In principle, it is even of advantage when the resonators are not round or rectangular, because regular shapes have many additional (mostly unwanted) vibrational modes of similar resonance frequency.
In connection with the subject of the present invention, however, it is to be noted that the shape of the resonator/mirror is insignificant. The structured layers may thus all be equally large or not (i.e. cuboids or truncated pyramid or the like).
Furthermore, the present invention is independent of the thickness of the layers in the mirror. The acoustic mirror usually is no λ/4 mirror, since there are various modes and wave types (longitudinal/shear waves). For this reason, it is mostly favorable to make the layer construction not periodic, i.e. each layer has different thickness.
The above description of the preferred embodiments substantially refers to the acoustically or electrically relevant layers in the mirror. In addition to these layers, however, also further layers or intermediate layers may be provided. For example, in the mirror structure and in the resonator structure arranged thereupon, one or more structured or unstructured intermediate layers serving as etch stop layers and/or adhesion-promoting layers may be provided. Furthermore, such intermediate layers may serve for further influencing the acoustic properties of the mirror, the resonator structure, or the overall structure. Furthermore, on the resonator structure or the overall structure, one or more structured or unstructured layers for protection and/or for further influencing the acoustic properties of the overall structure may be applied, for example tuning layers and/or passivation layers.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
REFERENCE NUMERAL LIST
100
substrate,
102
lower surface of the substrate,
104
upper surface of the substrate,
106
layer sequence of the mirror,
106a
layer with high acoustic impedance,
106a 1 , 106a 2
layer with high acoustic impedance,
106b
layer with low acoustic impedance,
106b 1 , 106b 2
layer with low acoustic impedance,
108
insulation layer,
110
lower electrode,
112
piezoelectric layer,
114
insulation layer,
116a, 116b
open regions in the insulation layer 114,
118
upper electrode,
118a, 118b
upper electrode,
120a, 120b
tuning layer,
122
BAW resonator,
122a, 122b
BAW resonator,
124
oxide layer,
126
depression,
128
insulation layer,
130
key topology,
132
planarization layer,
132a, 132b
ridges of the planarization layer,
134
opened region of the planarization layer,
136
surface of the first 106a 1 ,
138
surface of the planarization layer,
140
layer
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A mirror for a piezoelectric resonator consisting of alternately arranged layers of high and low acoustic impedance is manufactured by at first producing a first layer on which a second layer is produced, so that the second layer partially covers the first layer. Then, a planarization layer is applied on the first layer and on the second layer. Subsequently, a portion of the second layer is exposed by structuring the planarization layer, wherein the portion is associated with an active region of the piezoelectric resonator. Finally, the resulting structure is planarized by removing the portions of the planarization layer remaining outside the portion.
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TECHNICAL FIELD
The present invention relates generally to a collection of parts able to be assembled in various manners to form, among other things, a scaffold-like unit for supporting a mechanic in a working position above a working point, a protection device to be used with or without a mechanic's creeper to prevent injury to a mechanic in a working position below a working point, and a hoist frame for supporting heavy objects such as, for example, an automobile engine.
BACKGROUND OF THE INVENTION
When working on machines, for example, an automobile, it is necessary for a mechanic to work in various positions on, above, and underneath the automobile. When working above an automobile, it is desirable for the mechanic to be situated directly above the area being worked upon so that the mechanic can best view the work area. In addition, it is desirable that the mechanic may have free use of his or her hands. U.S. Pat. No. 4,618,029 to Lowry discloses an adjustable apparatus which includes a support means parallel to the ground to enable a mechanic to lean out over an engine and easily work on the engine below him. Vertical support members are situated at one end of the support means; no support structure is suggested at the other end of the Lowry structure.
U.S. Pat. No. 4,072,209 to Bolis and U.S. Pat. No. 2,970,668 to Snyder both teach support means for supporting a mechanic at an angular position over an engine to alleviate stress on the back, neck, etc.
It also desirable for a mechanic to be protected from objects falling down from the machine being repaired when the mechanic is underneath the machine. U.S. Pat. No. 1,431,383 to Edwards teaches the use of a protective shield attached to a mechanic's creeper to deflect foreign matter falling towards the eyes of the mechanic. The device of Edwards does not protect against injury due to the falling of large objects. None of these devices will adequately support a person above a work area, nor can they be used to protect a person from injury caused by heavy falling objects.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a device for comfortably, safely and stably supporting a person over a work area while permitting freedom of motion of the person's arms.
It is another object of this invention to provide a device which enables a person to work underneath a machine, such as an automobile, and be protected against injury caused by falling of large objects, including the automobile itself.
It is a further object of this invention to provide a support device for supporting large objects off of the ground.
It is a still further object of this invention to provide a collection of parts which can be assembled to form any of the devices set forth in the preceding three paragraphs.
According to the present invention, there is provided a collection of parts which can be assembled to form a cage-like structure, usable with or without a mechanics creeper, to protect a mechanic working under a vehicle; a scaffold-like device that is placeable over the engine compartment of a vehicle and which provides support portions enabling support of a mechanic over the engine compartment; and a support device which can support, among other things, large objects such as an automobile engine.
These together with other objects and advantages which will be subsequently apparent, reside in the details of construction and operation is more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a handlebar portion according to the present invention;
FIG. 2 is a side view of an elbow portion according to the present invention;
FIG. 3 is a side view of a straight portion according to the present invention;
FIG. 4 is a perspective view of a first structure assembled in accordance with the present invention;
FIG. 5 is a top view of end portion 124 of the structure of FIG. 4;
FIG. 6 is a perspective view of an alternative embodiment of the structure of FIG. 5;
FIG. 7 is a cross sectional side view of the assembly of FIG. 6;
FIG. 8 is a perspective view of a second structure assembled in accordance with the present invention;
FIG. 9 is a top view of the structure of the FIG. 8;
FIG. 10 is a perspective view of a third structure assembled in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention comprises pipes formed into three basic shapes and connectable to form various useful devices.
FIGS. 1-3 illustrate the three basic pipe shapes of the present invention. FIG. 1 illustrates what is hereinafter referred to as a "handlebar" portion. The handlebar portion comprises a length of tubing 1 having, for example, an outside diameter of 1.3 inches and having a center portion 10 and ends 12 and 14. Preferably, the tubing 1 comprises 40 gauge water pipe. Ends 12 and 14 each have two bends 16 and 18 formed therein. Each bend 16 forms an angle Σ of approximately 115 degrees. Each bend 18 forms an angle β of approximately 90 degrees. The tubing bent in this manner forms a handlebar shape.
FIG. 2 illustrates an elbow portion 20. Elbow portion 20 is a piece of tubing similar to that used to form the handlebar portion 1 illustrated in FIG. 1, however, it is preferable to use Electrical Metallic Tubing (EMT) having an outside diameter of 1.5 inches and a thickness of 0.065 inches. The tubing is bent to form bend 22 such that the arms 24 and 26 of the elbow are equal in length and perpendicular to each other.
FIG. 3 illustrates a coupling portion 30. The coupling portion 30, in a preferred embodiment, is a straight piece of tubing of the same gauge and thickness as that used for the handlebar portions, but the inside diameter of coupling portion 30 is such that the ends 12 and 14 of handlebar portion 1 and ends 24 and 26 of elbow portion 20 will fit snugly inside the ends of coupling portion 30. As will be more fully described below, several coupling portions of various lengths will be used.
FIGS. 4 and 5 illustrate a first structure 100, having end portions 122 and 124, formed using a combination of the pieces described in FIGS. 1-3. As shown in FIG. 4, two handlebar portions 101 are coupled together using two coupling portions 130. For this structure, the coupling portions 130 should be approximately 10" to 16" in length.
FIG. 5 is a top view of end portion 124 of assembly 100. The assembly 100 is assembled by inserting the ends 112 and 114 of handlebar portions 101 into coupling portions 130. The ends 112 and 114 of the handlebar portions 101 are fixedly attached to coupling portion 130 utilizing, for example, nuts 116 and 118, bolts, pins or other connection means inserted into holes drilled in through the ends of 112 and 114 and through coupling portion 130 as shown in FIG. 5.
When assembled as described above, the pieces form a cage-like type structure which may be used as follows. The vehicle to be worked on is jacked up to the desired height. At minimum, in order to use the assembly 100, the vehicle must be jacked up to a height enabling the assembly 100 to be slipped underneath the vehicle. Once the assembly 100 is inserted underneath the car, the user may crawl underneath the car and be protected by it. Preferably, the user will crawl between the two handlebar portions 101, so that, in the event that the vehicle were to fall off the jack, the user would be inside the "cage" formed by the assembly 100. The assembly 100 will support the vehicle and allow the user to get out from under the vehicle safely.
FIGS. 6 and 7 illustrate an alternative embodiment in which the assembly 100 is coupled with a mechanic's "creeper" 120 to allow easy maneuvering of the roll bar assembly while maneuvering underneath the vehicle. FIG. 6 is a perspective view of assembly 100 with the mechanic's creeper attached. FIG. 7 is a cross-sectional side view of the assembly of FIG. 6.
A standard mechanic's creeper is available from most auto parts stores or Sears, Roebuck and Co., and is approximately 36" in length. The handlebar portions 101 are formed so that the distance between end portions 122 and 124 is such that the mechanic's creeper can fit snugly between them i.e., the length of the creeper should be slightly smaller than the distance between end portions 122 and 124. The assembly 100 is placed over the creeper and is attached to ends 126 and 128 of the creeper 120 using, for example, strapping material 129 wrapped around the end pieces 122 and 124 of the assembly 100 and bolted into the creeper 120, as shown in FIG. 6, using nuts 130 and bolts 132. The strapping material can be, for example, a piece of sheet metal wrapped around end pieces 122 and 124 and bolted to the creeper. When attached in this manner, the user can lie comfortably on the creeper 120 and maneuver underneath the vehicle while being protected by the cage-like structure.
FIGS. 8 and 9 illustrate a second structure 200, herein after referred to as a "support structure," formed using a different combination of the pieces described in FIGS. 1-3. As shown in FIG. 8, two handlebar portions 201 (FIG. 1), four elbow portions 220 (FIG. 2), four coupling portions 231 (FIG. 3) of a length approximately one foot longer than the distance from the ground to the highest portion of the hood of the vehicle, and two straight portions 232 (FIG. 3) of a length approximately one foot wider than the width of the vehicle are required.
The support structure 200 is assembled by inserting one end of each of the four coupling portions 231 onto the ends of the handlebar portions 201. An elbow 220 is then coupled to the other end of each of the four coupling portions 230. Finally, the elbow portions are coupled to each other as shown in FIG. 6 using the coupling portions 232. Each of the sections are secured to each other in the same manner as described with respect to FIG. 5.
FIG. 9 is a top view looking down onto support structure 200. When assembled, a creeper 240 is slideably attached across the two coupling portions 232 as shown in FIG. 9, to provide a moveable surface across which the user can lie. The creeper can be attached in the same manner as described with respect to FIGS. 6 and 7. If desired, a second creeper can be attached to provide a work surface/tool tray or to provide further support for the user. An assembly so formed can be used by a mechanic to lean or to lie over the engine to be worked on, thereby reducing the back strain caused by leaning over the engine without the support. In addition, tools are easily accessible and the mechanic's hands are free to move about to work on the engine below. The user can lie across both creepers or can lean on one and use the other to hold tools.
FIG. 10 illustrates a third structure 300, hereinafter referred to as a hoisting device, formed using another combination of the basic pieces described in FIGS. 1-3. In FIG. 8, two handlebar portions 301 (FIG. 1), four elbow pieces 320 (FIG. 2), four coupling portions 331 of a length approximately 11/2 times the distance from the ground to the highest portion of the hood of a vehicle, and two coupling portions 332 of a length approximately two feet longer than the width of the vehicle are required.
To assemble the hoisting device 300, the coupling portions 331 are inserted onto the four ends of the handlebar portions 301 as shown in FIG. 10. The four elbow portions 320 are inserted into the other end of each of the coupling portions 331. The elbows 320 ar coupled to each other using coupling portions 332, as shown in FIG. 10. Each of the sections are secured to each other in the same manner as described with respect to FIG. 5. Where the two coupling portions 332 cross each other, a chain 340 or other similar means is wrapped around the intersecting cross pieces, and a hoisting mechanism 342 for example, a block and tackle or similar device is connected to the chain. The device thus assembled can be placed over, for example, the engine of an automobile. If the motor mounts of the vehicle are then loosened and the engine of the vehicle is attached to the hoisting means 342, the engine can be pulled out from the vehicle and then the vehicle can be moved away from the engine, leaving the engine hanging from the hoisting device 300. It then can be lowered onto a hand truck or worked on while it hangs from the hoisting device 300.
As discussed above, at least three different structures for use in automobile repair can be formed using the three basic pieces illustrated in FIGS. 1-3. The device can be disassembled and stored easily, perhaps even in the trunk of a car, for use in emergency situations.
The many features and advantages of the invention are apparent from the detailed specification and thus it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention. For example, the disclosed invention includes elbow portions having "arms" of equal length. However, the invention can instead be made using elbow portions having "arms" of different lengths. In addition, various other materials and pipe sizes can be used other than those disclosed herein.
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A collection of parts which can be assembled to form a cage-like structure, usable with or without a mechanics creeper, to protect a mechanic working under a vehicle; a scaffold-like device that is placeable over the engine compartment of a vehicle and which provides support portions enabling support of a mechanic over the engine compartment; and a support device which can support, among other things, large objects such as an automobile engine.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 10/587,320, filed May 10, 2007, which is the National Phase of International Application No. PCT/JP2005/001187 having an international filing date of Jan. 28, 2005, and claims the benefit of Japanese Application 2004-022547, filed Jan. 30, 2004, the entireties of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a new use of a hydantoin derivative, in particular, (2S,4S)-6-fluoro-2′,5′-dioxospiro [chroman-4,4′-imidazolidine]-2-carboxamide, as a pharmaceutical preparation.
[0004] 2. Description of the Related Art
[0005] The number of patients with diabetes mellitus as a life style-related disease is increasing, and in a survey on diabetes mellitus in 2002 conducted by the Ministry of Health, Labor and Welfare, the number of patients with diabetes mellitus in Japan is estimated to be 7.4 millions. In a recent epidemiological study on 913 cases of non-insulin-dependent diabetes mellitus, about 8% (about 600,000 patients) of patients with diabetes mellitus are reported to have maculopathy. It is estimated that as the number of patients with diabetes mellitus increases, the number of patients with diabetic maculopathy also increases.
[0006] Diabetic maculopathy, together with diabetic retinopathy, is considered to be important as one of the retinal diseases inpatients with diabetes mellitus. Diabetic maculopathy is classified into macular edema, ischemic maculopathy, retinal pigment epitheliopathy and macular traction. The object of diabetic retinopathy therapy is to prevent blindness (loss of visual acuity), while the object of diabetic maculopathy therapy is to prevent and ameliorate deterioration of visual acuity. Macula lutea are significantly different in form from retinas so as to attain high central visual acuity (sharpest and high visual acuity), and have a special structure (absent from an inner plexiform layer and an inner nuclear layer) with extremely fewer tissues other than visual cells. Accordingly, the clinically problematic deterioration of visual acuity is due to maculopathy. A development of photocoagulation and vitrectomy made it possible to almost prevent blindness attributable to retinopathy, but is not satisfactory for maculopathy, so a therapy that is different from retinopathy therapy is needed for maculopathy. This is also important in light of the treatment of many patients having maculopathy only without having retinopathy. Especially, a recent increase in pan-photocoagulation for diabetic retinopathy is estimated to worsen macular edema in diabetic maculopathy, to cause further deterioration of visual acuity. Accordingly, the main point of therapy is shifting toward improvement of quality of life (QOL) of patients by maintaining and improving visual acuity.
[0007] Macular edema caused by breakage of a blood-retinal barrier in a retinal vascular endothelial cell or a retinal pigment epithelial cell accounts for about 90% of maculopathy and is a major cause for deterioration of visual acuity in maculopathy. This deterioration of visual acuity does not lead to blindness, but causes extreme deterioration of visual acuity referred to as social blindness making usual living difficult. On one hand, the average life span increases due to the advancement of medical technology, and thus, such a deterioration of visual acuity is a serious problem that cannot be neglected in consideration of QOL. Major therapy conducted for preventing or ameliorating deterioration of visual acuity includes photocoagulation, vitrectomy and chemotherapy. Under the present circumstances, photocoagulation and vitrectomy are examined for their effectiveness in clinical studies, and the effectiveness and safety for macular edema have still not been established. There are cases where complications of neovascular glaucoma and worsening edema occur, and thus, there is an earnest desire for the advent of an effective and safe chemotherapy. In the present chemotherapy, steroids and carbonate dehydratase inhibitors with anti-inflammatory action as major efficacy are used in symptomatic therapy, but their effectiveness is not established and their administration over a long period of time leads to the occurrence of side effects, and thus, the continuous use thereof in chronic diseases such as diabetes mellitus is not desirable under the present circumstance.
[0008] (2S,4S)-6-Fluoro-2′,5′-dioxospiro[chroman-4,4′-imidazolidine]-2-carboxamide (hereinafter, referred to as SNK-860) found by the present applicant was developed as a compound which has a strong inhibitory activity on aldose reductase and is highly safe even in administration for a long time, and clinical test thereof as a therapeutic agent for diabetic neuropathy is advancing worldwide at present.
[0009] With respect to hydantoin derivatives including SNK-860, the use thereof for diabetic neuropathy is described in JP-A 61-200991 (1986), the use thereof for diseases in circulatory organs in JP-A 04-173791 (1992), the use thereof for various diseases accompanying aging in JP-A 06-135968 (1994), the use thereof for simple diabetic retinopathy in JP-A 07-242547 (1995), and the use thereof for diabetic keratopathy in JP-A 08-231549 (1996). However, the effectiveness of the hydantoin derivatives for diabetic maculopathy has not been reported.
[0010] As described above, establishing an effective and highly safe therapy for treating diabetic maculopathy is strongly desired in the medical field. Under the present circumstances, the advent of a highly safe chemotherapy enabling administration over a long time period is strongly desired because of the safety problems associated with treatment by opthalmologic operation. However, heretofore, there has been no model for evaluating experimental diabetic maculopathy, which is important for the development of such therapeutic agents, and the establishment of an experimental model for development of pharmaceutical preparations is an urgent task.
SUMMARY OF THE INVENTION
[0011] The present invention has been made in consideration of the drawbacks associated with the prior art as described above, and an object of the present invention is to provide a prophylactic or therapeutic agent for treating diabetic maculopathy, which can be administered over a long period of time which and exhibits efficacy in a mechanism different from that of existing medicines, as well as an experimental animal model which can be used in the evaluation of medicines for diabetic maculopathy.
[0012] The present inventors first sought to establish an experimental animal model for diabetic maculopathy. That is, simplicidentata such as rats have no macula lutea, and there is no report on edema at a site outside of a retina such as a visual cell layer, that is, at a site corresponding to macula lutea, and whether its severeness is increased or decreased by diabetes mellitus is not reported either. Accordingly, the present inventors studied its pathologic condition using an animal, and as a result we found that when a diabetic rat was allowed to be in an intraocular ischemic state and then subjected to reperfusion, edema was expressed on a visual cell layer. In this experimental model, it is suggested that an increase in oxidation stress, such as excessive production of free radicals occurring in the eye by ischemia and reperfusion, promotes vascular permeability by breaking an inner blood-retinal barrier (barrier regulating the transfer of a substance from a retinal blood vessel to the outside of the blood vessel) and an outer blood-retinal barrier (barrier regulating the transfer of a substance from a choroid to retina). Accordingly, it is estimated that the edema was expressed by this promotion of vascular permeability in addition to the promotion of retinal vascular permeability by diabetes mellitus. The present model thus expressing edema in the visual cell layer has an onset mechanism very similar to that of macular edema in human diabetic maculopathy and can be said to be a model suitable for the evaluation of diabetic maculopathy.
[0013] The present inventors also examined whether or not edema was expressed in a macula lutea in a diabetic monkey by using an evaluation system established in rats. As a result, it was confirmed that edema is observed in a macular central fovea participating most in central visual acuity. This can be said to further evidence that the edema-expressing model established in a rat is suitable in evaluation of diabetic maculopathy.
[0014] When the present inventors used the above-mentioned experimental model to evaluate SNK-860, the inventors discovered that SNK-860 is effective for edema in a retinal visual cell layer having a central role in maintaining visual acuity or for edema in a macula lutea (particularly macular central fovea). By conducting further clinical evaluations, the present inventors discovered that the compound is not only effective for treating edema in a macula lutea, but also exhibits an effect of improving visual acuity. That is, the present invention relates to a prophylactic or therapeutic agent for treating diabetic maculopathy, which comprises, as an active ingredient, a hydantoin derivative represented by the following general formula, preferably (2S,4S)-6-fluoro-2′,5′-dioxospiro [chroman-4,4′-imidazolidine]-2-carboxamide (SNK-860)
[0000]
[0015] (In the formula, X represents a halogen or a hydrogen atom, R 1 and R 2 concurrently or differently represent a hydrogen atom or an optionally substituted C1 to C6 alkyl group, or R 1 and R 2 , together with a nitrogen atom bound thereto and optionally another nitrogen atom or an oxygen atom, are combined to form a 5- to 6-membered heterocycle, and the halogen represented by X is preferably fluorine, and the C1 to C6 alkyl group is preferably a methyl group.)
[0016] Examples of the diabetic maculopathy include macular edema and retinal pigment epitheliopathy. Examples of the diabetic macular edema include local macular edema and diffuse macular edema. The prophylactic or therapeutic agent for diabetic maculopathy according to the present invention is preferably in the form of an oral agent.
[0017] The present invention also relates to an experimental animal model with diabetic maculopathy, which uses an animal such as simplicidentata or primates other than humans. This is an animal model with diabetic maculopathy that is produced by subjecting a diabetic animal to intraocular ischemia/reperfusion to express edema in a retinal visual cell layer or in a macula lutea (particularly in macular central fovea). As the animal with diabetes mellitus, it is possible to use not only animals having diabetes mellitus induced for example by administering a pharmacological agent such as streptozotocin or alloxan into a rat (normal rat) or a monkey (normal monkey), but also animals with hereditary diabetes mellitus.
[0018] Further, the present invention encompasses a method of evaluating a pharmacological agent for diabetic maculopathy, which comprises using the model animal described above. That is, the method of the present invention is a method of evaluating the effectiveness of a pharmacological agent on edema, which comprises administering a pharmacological agent to be evaluated into the model animal and measuring the thickness of a retinal visual cell layer or the thickness and/or volume of a macula lutea.
[0019] The present invention provides not only a therapeutic agent for diabetic maculopathy, which can be administered over a long period of time, but also an experimental animal model that is needed in order to conduct research to discover a therapeutic agent for diabetic maculopathy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows the ratio of the thickness of a retinal visual cell layer (ratio (%) of the thickness of a visual cell layer in an ischemic/re-perfused eye/the thickness of a visual cell layer in an untreated eye in the same individual) in Efficacy Pharmacological Test Example 1. In FIG. 1 , the asterisk indicates that there is a significant difference with a risk factor of 5%.
[0021] FIG. 2 shows the ratio of the thickness of a retina visual cell layer (ratio (%) of the thickness of a visual cell layer in an ischemic/re-perfused eye/the thickness of a visual cell layer in an untreated eye in the same individual) in Efficacy Pharmacological Test Example 2. In FIG. 2 , the asterisk indicates that there is a significant difference with a risk factor of 5%.
[0022] FIG. 3 shows a change in the minimum thickness, average thickness and average volume of macular central fovea in an ischemic/re-perfused eye in Efficacy Pharmacological Test Example 3. In FIG. 3 , the asterisk indicates that there is a significant difference with a risk factor of 5%.
[0023] FIG. 4 shows the thickness of a macula lutea in a macular central fovea (diameter: 1 rum) and in the center of the central fovea before and after administration in Efficacy Pharmacological Test Example 4.
[0024] FIG. 5 shows a change in the thickness of a macula lutea in individual eyes (upper graph, in the center of a central fovea; lower graph, in the central fovea in the diameter range of 1 mm) before and after administration in Efficacy Pharmacological Test Example 4. A number in the example indicates identification number of the case, and alphabets OS and OD refer to left and right eyes, respectively.
[0025] FIG. 6 shows corrected visual acuity before and after administration in Efficacy Pharmacological Test Example 4.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Hereinafter, the present invention is described in more detail.
[0027] Hydantoin derivatives (particularly SNK-860) can be orally administered for example as tablets, capsules, powder, granules, liquid or syrup or parenterally as an injection and suppositories, which were formed by usual pharmaceutical manufacturing techniques. Pharmaceutically acceptable excipients in pharmaceutical manufacturing, for example starch, lactose, refined white sugar, glucose, crystalline cellulose, carboxy cellulose, carboxymethyl cellulose, carboxyethyl cellulose, calcium phosphate, magnesium stearate and gum arabic can be used in the solid preparation, and if necessary a lubricant, a binder, a disintegrating agent, a coating agent, a coloring agent etc. can be incorporated into the solid preparation. In the liquid preparation, a stabilizer, a solubilizer, a suspending agent, an emulsifying agent, a buffer agent, a preservative etc. can be used. The dose varies depending on symptoms, age, administration method, preparation form etc., but preferably the compound described above is administered usually in the range of 1 to 200 mg, preferably 1 to 100 mg, into an adult all at once or in divided portions per day for consecutive days.
[0028] In the model animals with diabetic maculopathy according to the present invention, animals with diabetes mellitus by treating normal animals with a pharmacological agent such as streptozotocin (STZ), or alloxan or animals with hereditary diabetes mellitus, can be used as diabetic animals. As the type of the animals, simplicidentata such as rats, nonhuman primates such as monkeys, duplicidentata such as rabbits, and carnivorous animals such as canines can be used.
[0029] When the simplicidentata, duplicidentata or carnivorous animals that inherently do not have macula lutea are used, edema is expressed in a retinal visual cell layer and the thickness of the retinal visual cell layer can be used in evaluation. In the nonhuman primates, on the other hand, there are usually macula lutea, so edema is expressed in a macula lutea and the thickness and/or volume of the macula lutea is used in evaluation. The thickness etc. of the macula lutea are evaluated preferably in the site of macular central fovea. Intraocular ischemia/reperfusion treatment can be easily carried out by stopping a retinal blood stream by increasing the intraocular pressure and then relieving the intraocular pressure to allow reperfusion. The thickness of the retinal visual cell layer or the macula lutea varies significantly depending on individuals, so a treated eye and untreated eye are set preferably in the same individual by subjecting only one eye to intraocular ischemia/reperfusion treatment. By so doing, the relative evaluation of “thickness of a treated eye/thickness of an untreated eye” can be carried out on the basis of the untreated eye in each animal.
[0030] A pharmacological agent to be examined is administered into the model animal with diabetic maculopathy according to the present invention and then evaluated for the effectiveness of the pharmacological agent for edema as described above, whereby the effectiveness of the pharmacological agent for diabetic maculopathy can be evaluated. The method of administering the pharmacological agent is not particularly limited, and administration of the pharmacological agent is also carried out after intraocular ischemia/reperfusion treatment thereby clarifying the therapeutic effect.
EXAMPLES
Efficacy Pharmacological Test Example 1
Rat Test 1
1. Test Method
[0031] Diabetes mellitus was induced in male Sprague Dawley rats (8-week-old) weighing about 250 g by injecting streptozotocin (STZ manufactured by Sigma) intravenously into their tail at the dose of 60 mg/kg. One week after the treatment with STZ, serum glucose was measured, and rats with at least 300 mg/dl glucose were then used in the experiment as diabetic rats. The set groups were the following 3 groups, and after 2 weeks after the treatment with STZ, 5% gum arabic solution or SNK-860 solution was orally administered once a day.
[0000] (1) Normal control group (5 rats): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(2) Diabetic control group (7 rats): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(3) Diabetic group given 32 mg/kg SNK-860 (4 rats): Given a suspension of SNK-860 (32 mg/5 ml) in 5% gum arabic solution in a ratio of 5 ml/kg.
[0032] After administration for 2 weeks, intraocular ischemia was caused by the treatment described below. After the treatment was finished, the animals were maintained as usual for 2 days, and thereafter, the eyeballs were excised and histologically evaluated. Administration of the pharmacological agent was also conducted for a period (2 days) of reperfusion after ischemic treatment.
Retinal Ischemia by Increasing the Intraocular Pressure
[0033] A drip infusion set (Terufusion Drip Infusion Set manufactured by Terumo) was connected to a bottle containing an intraocular perfusion solution (Opeguard MA manufactured by Senjyu Seiyaku), and an extension tube (Terumo) to which a three-way stopcock had been attached was connected thereto. A needle (30 G×½, manufactured by Nippon Becton Dickinton) was fitted to the end of the tube. The bottle containing an intraocular perfusion solution was fixed to a certain height with a stand. The rats were anesthetized by administering sodium pentobarbital (Somunopentyl manufactured by Schering-Plough Animal Health) intraperitoneally in a ratio of 50 mg/kg, and then a mydriatic (Mydrin P manufactured by Santen Pharmaceutical) and a local anesthetic (Benoxyl eye drop 0.4%, Santen Pharmaceutical) were dropped onto the right eye. The anesthetic was additionally administered when necessary. Thereafter, a needle was stuck into an anterior chamber of the rat right eye and the intraocular pressure load was performed by manipulating the three-way stopcock (the intraocular pressure was increased to 130 mmHg or more for 60 minutes). Because the ocular fundus in the Sprague Dawley rat turns from red to white by stopping the retinal blood stream by increasing the intraocular pressure, achievement of retinal ischemia can be easily observed. After the intraocular pressure was increased for the predetermined time, the needle was removed to relieve the intraocular pressure to allow reperfusion, and an antibacterial eye drop (tarivit eye ointment manufactured by Santen Pharmaceutical) was applied onto the right eye.
Histological Evaluation
[0034] Two days after the ischemia treatment (two days after the reperfusion), the rat left and right eyeballs were excised under anesthesia with ether. The excised eyeballs were placed in an ice-cold fixing solution (phosphate buffer solution containing 3% glutaraldehyde) and fixed therein for 2 days. Thereafter, the eyeballs were washed for 1 day with a phosphate buffer solution. The eyeballs were embedded in a usual manner into paraffin to prepare a transverse section containing a bundle of optic nerves. The section was stained with hematoxylin-eosin. The histological evaluation was conducted by each of two (2) visual fields in left and right side (4 visual fields/rat) in the vicinity of the bundle of optic nerves, from an optical microscope to an image analyzer (IPAP-WIN, Sumika Techno Service).
[0035] In each of the resulting retinal images, the thickness of the visual cell layer was measured. The degree of edema was expressed in percentage by dividing the thickness of the visual cell layer of the ischemic/re-perfused eyeball (right eye) by the thickness of the visual cell layer of the untreated eyeball (left eye) in the same individual. As an indicator of retinal cell functions, nuclei in the inner retinal layer (ganglion cell layer) were counted, and the degree of loss of nuclei was evaluated relative to the ratio of the number of nuclei occurring per unit area.
2. Results and Discussion
[0036] The effect of SNK-860 on edema is shown in FIG. 1 . The thickness of the visual cell layer after ischemia/reperfusion in the rats in the normal control group was reduced as compared with that of the untreated eye. On the other hand, the rats in the diabetic control group showed an increase in the visual cell layer by ischemia/reperfusion, and formation of edema was confirmed (p<0.05). In the diabetic group given 32 mg/kg SNK-860, the thickness was almost the same as that of the normal control group, and no edema was observed.
[0037] Next, loss of nuclei from ganglion cells is described. As a result of examination of the degree of loss of nuclei from cells, no loss of nuclei was recognized in 5 rats in the normal control group. In the diabetic control group, evident loss of nuclei occurred in 3 of 7 rats, among which 2 rats showed loss of 50% or more nuclei. In the diabetic group given 32 mg/kg SNK-860, loss of nuclei was not observed in all 4 rats.
[0038] These results reveal that SNK-860 inhibits edema formation under diabetes in a visual cell layer and also prevents disturbances in functions of retinal cells.
Efficacy Pharmacological Test Example 2
Rat Test 2
1. Test Method
[0039] The test was carried out in accordance with Efficacy Pharmacological Test Example 1. The set groups were the following 4 groups, and from 2 weeks after the treatment with STZ, 5% gum arabic solution or SNK-860 solution was orally administered once a day.
[0000] (1) Normal control group (10 rats): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(2) Diabetic control group (9 rats): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(3) Diabetic group given 2 mg/kg SNK-860 (10 rats): Given a suspension of SNK-860 (2 mg/5 ml) in 5% gum arabic solution in a ratio of 5 ml/kg.
(4) Diabetic group given 32 mg/kg SNK-860 (9 rats): Given a suspension of SNK-860 (32 mg/5 ml) in 5% gum arabic solution in a ratio of 5 ml/kg.
[0040] Retinal ischemia produced by increasing the intraocular pressure was in accordance with Efficacy Pharmaceutical Test Example 1. Histological evaluation was also in accordance with Efficacy Pharmaceutical Test Example 1.
2. Results and Discussion
[0041] The effect of SNK-860 on edema is shown in FIG. 2 . The thickness of the visual cell layer after ischemia/reperfusion in the rats in the normal control group was reduced as compared with that of the untreated eye. On the other hand, the rats in the diabetic control group showed an increase in the visual cell layer by ischemia/reperfusion, and formation of edema was confirmed (p<0.05). In the diabetic group given 2 mg/kg SNK-860, no inhibitory action on edema was observed, but in the diabetic group given 32 mg/kg SNK-860, the thickness of the visual cell layer was kept in the same value as in the normal control group, and an evident inhibitory action on edema was observed. These results indicate that edema formation under diabetes in a visual cell layer is inhibited by administration of a high dose of SNK-860.
Efficacy Pharmacological Test Example 3
Monkey ( Macaca fascicularis ) Test
1. Method
[0042] Diabetes mellitus was induced in male monkeys ( Macaca fascicularis ) (3-year-old) weighing about 2.1 to 2.4 kg by intravenously injecting STZ into their foreleg vein at the dose of 80 mg/kg. Two days after the treatment with STZ, blood glucose level was measured, and monkeys with at least 200 mg/dl glucose were then used in the experiment as diabetic monkeys. Insulin was administered subcutaneously once or twice per day into monkeys showing a blood glucose level of 300 mg/dl. The set groups were the following 3 groups, and from 2 weeks after the treatment with STZ, 5% gum arabic solution or SNK-860 solution was orally administered once a day.
[0000] (1) Normal control group (4 monkeys): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(2) Diabetic control group (6 monkeys): Given 5% gum arabic solution in a ratio of 5 ml/kg.
(3) Diabetic group given 32 mg/kg SNK-860 (4 monkeys): Given a suspension of SNK-860 (32 mg/5 ml) in 5% gum arabic solution in a ratio of 5 ml/kg.
[0043] After administration for 2 weeks, intraocular ischemic treatment was carried out as described below, and after the treatment was finished, the animals were maintained as usual for 7 days. Before the ischemic treatment and 7 days after treatment, the thickness and volume of the macular central fovea (in the diameter range of 1 mm from the center of the macula lutea) were measured by an OCT scanner (Stratus OCT, Carl Zeiss). Administration of the pharmacological agent was also conducted for the period (7 days) of reperfusion after the ischemic treatment.
[0044] Retinal ischemia produced by increasing intraocular pressure was in accordance with Efficacy Pharmaceutical Test Example 1. However, the size of the needle used was 25 G×½ (Terumo). After a mydriatic (Mydrin P manufactured by Santen Pharmaceutical) was dropped onto the right eye, the monkey was anesthetized by intramuscularly administering ketaral (Sankyo Life Tech). Subsequently, a local anesthetic (Benoxyl eye drop 0.4%) was dropped onto the eye, and the monkey was prevented from blinking with an eyelid speculum. Anesthesia with ketaral was additionally carried out when necessary.
[0045] The thickness and volume of the macular central fovea were measured in the following manner. After a mydriatic (Mydrin P) was dropped onto the right eye of the monkey to dilate the pupil of the eye sufficiently, the monkey was anesthetized by intramuscularly administering Ketaral. Thereafter, the monkey was allowed to sit on a monkey chair and the head was fixed. The inside of the eye was observed with an OCT scanner to identify the macula lutea, followed by scanning. On the basis of the resulting cross-sectional macular image, the thickness and volume of the macular central fovea were analyzed.
[0000]
TABLE 1
Average macula lutea
Average macula lutea
thickness (μm)
volume (mm 3 )
Number
Before
7 days after
Before
7 days after
Group
of monkeys
ischemia
ischemia
ischemia
ischemia
Normal
4
174 ± 8
175 ± 11
0.137 ± 0.006
0.138 ± 0.009
Diabetes
6
177 ± 6
191 ± 5**
0.139 ± 0.005
0.149 ± 0.004**
mellitus
Diabetes
4
157 ± 6
158 ± 2
0.123 ± 0.005
0.124 ± 0.001
mellitus
given 860
**P < 0.01 vs. “value before ischemia”.
2. Results
[0046] The results are shown in Table 1 and FIG. 3 . In the normal control group, formation of edema was not observed, and the thickness and volume (average) of the macular central fovea after ischemia and reperfusion were the same before the treatment and 7 days after the treatment. In the diabetic control group, on the other hand, an increase in the thickness and volume of the macular central fovea was observed 7 days after the treatment, and formation of edema was confirmed (p<0.01). This change was significantly increased as compared with that of the normal control group (p<0.05). In the diabetic group given 32 mg/kg SNK-860, formation of edema or its change was not observed similarly to the normal control group. These results show that SNK-860 inhibits edema formation under diabetes in the macular central fovea.
Efficacy Pharmacological Test Example 4
Clinical Results
1. Method
[0047] Among patients with diabetic maculopathy, 10 patients with diabetic macular edema having a retinal thickening or a hard exudates in a posterior pole of the retina were subjects. SNK-860 was orally administered in a dose of 30 mg (2 tablets each containing 15 mg SNK-860) once a day before breakfast for 8 weeks. During this test period, simultaneous use of eparlestat, intravitreal injection and sub-Tenon injection of an adrenal cortical hormone, and photocoagulation and vitrectomy were prohibited. Basic therapy of diabetes mellitus was carried out so as to give good blood glucose control throughout the test period.
[0048] Evaluation was carried out in terms of the thickness of the macular central fovea (in the diameter range of 1 mm from the center of macula lutea) and the thickness at the center of the central fovea measured by optical coherence tomography (OCT, Carl Zeiss), as well as corrected visual acuity (Log MAR).
[0049] Log MAR (Log Minimum Angle of Resolution) is one kind of logarithmic visual acuity, which is visual acuity expressed in logarithmic minimum angle of resolution. Decimal visual acuity 1.0 used frequently in Japan is 0.0 in terms of Log MAR, and decimal visual acuity 0.1 is 1.0 in Log MAR. A log MAR visual acuity of 0.1 to 0.5 corresponds to a decimal visual acuity of 0.8 to 0.32.
[0000]
TABLE 2
Macula lutea thickness (μm) and corrected visual acuity
(Log MAR) (mean ± standard deviation)
When initiated
Week 8
P value
Center of central fovea
323.1 ± 111.4
298.7 ± 90.6
0.0808
Central fovea (diameter: 1 mm)
324.3 ± 87.7
300.4 ± 74.4
0.0493
Corrected visual acuity
0.30 ± 0.22
0.24 ± 0.20
0.0917
[0000]
TABLE 3
Corrected visual acuity (eye number)
2-stage
1-stage
1-stage
improvement
improvement
Unchanged
deterioration
3
2
6
1
2. Results
[0050] 12 eyes in the 10 cases were evaluated. When the test was initiated, the thickness of the macular central fovea (in the diameter range of 1 mm) was 324.3 μm on average, and the thickness at the center of the central fovea was 323.1 μm on average. After 8 weeks, these were reduced 300.4 μm and 298.7 μm respectively (Table 2, FIG. 4 ). A change in the thickness of macula lutea in the individual evaluated eye is shown in FIG. 5 . These results show that the thickness of the macula lutea or the portion corresponding to the macula lutea in the model animal was also confirmed similarly in humans.
[0051] Out of the 12 eyes, 2-stage development with respect to corrected visual acuity was recognized in 3 eyes, 1-stage development in 2 eyes, and deterioration in only 1 eye (Table 3). The corrected visual acuity (Log MAR) on average was improved from 0.30 to 0.24 ( FIG. 6 ). It was thus revealed that SNK-860 has a visual acuity-improving action important in therapy of maculopathy.
[0052] Diabetic maculopathy according to conventional findings is a gradually worsening disease that is considered difficult to treat. In contrast, the results of the present examples indicate that SNK-860 is effective for diabetic maculopathy. With respect to safety, no particularly problematic side effects were recognized.
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A prophylactic or therapeutic agent for diabeticmaculopathy, which can be administered for a long time and exhibits efficacy in a mechanism different from that of existing medicines. The invention relates to a prophylactic or therapeutic agent for diabetic maculopathy, comprising, as an active ingredient, a compound represented by the general formula:
wherein X represents a halogen or a hydrogen atom, R 1 and R 2 concurrently or differently represent a hydrogen atom or an optionally substituted C1 to C6 alkyl group, or R 1 and R 2 , together with a nitrogen atom bound thereto and optionally another nitrogen atom or an oxygen atom, are combined to form a 5- to 6-membered heterocycle. Preferably, the compound is (2S,4S)-6-fluoro-2′,5′-dioxospiro chroman-4,4′-imidazolidine]-2-carboxamide. The invention also provides a model animal with diabetic maculopathy produced by subjecting a diabetic animal to intraocular ischemia/reperfusion to express edema in a retinal visual cell layer or in a macula lutea.
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FIELD OF THE INVENTION
This invention relates to removable reusable insulation covers generally used for insulating structures such as valves and flanges.
BACKGROUND OF THE INVENTION
Structures used in industrial applications such as valves and flanges with sharp protrusions frequently require insulation. These objects often require inspection, thus necessitating frequent removal of the insulation. If permanent insulation is used on the object then each time the insulation is removed new insulation must be put back on. This is time consuming, sometimes difficult to schedule and in many instances prohibitively expensive. The most practical method to insulate these types of objects is to utilise a removable and reusable insulating jacket. There are a number of such systems available and they do insulate and are removable and reusable as required. An example is described in U.S. Pat. No. 4,807,669 issued Feb. 28, 1989, corresponding to Canadian patent no. 1,249,974 of Prestidge.
These systems in general include an insulating material, an outer covering to protect and keep the insulation dry and various fastening devices to seal and to secure the insulating jacket to the object. Some of the systems are flexible but not durable while some are durable but rigid. One type of system uses insulation covered with silicone impregnated fibreglass cloth. The inventor considers that the use of cloth renders the product liable to tearing during installation, hence is flexible at the expense of a decrease in durability.
Another type of system uses rigid insulation covered by sheet metal with the sections secured together with mechanical hinges, clasps or straps. Such a product is durable at the expense of loss of flexibility.
SUMMARY OF THE INVENTION
There is therefore provided an insulating cover that is designed to meet these problems, and thus provide an insulation cover that has enhance flexibility as compared with a metal cover, and enhanced durability when compared with a cloth cover. In accordance with a broad aspect of the invention there is provided a removable and reusable insulating cover for insulating an object with sharp protrusions.
According to one aspect of the invention there is provided an insulation cover comprising insulation coated with a coating material, for example completely coated, and a fastener attached to the coated insulation for removably securing the coated insulation to a structure to be insulated.
According to a further aspect of the invention, there is provided a method of installing an insulation cover. In such a method, there are provided the steps of obtaining insulation coated with a coating material; and removably attaching the coated insulation to a structure to be insulated.
According to a further aspect of the invention, there is provided a method of making an insulation cover. In such a method, there are provided the steps of applying coating material to insulation to form coated insulation; and attaching a fastener to the coated insulation for removably securing the coated insulation to a structure to be insulated.
Preferably, the insulation cover comprises a flap secured to the insulation, which is formed as part of the insulation cover and used as a support for the fastener.
The insulation may be provided as one or more segments of insulation, each individually coated, and which may be hinged together for example by one or more living hinges. Such a segmented hinged insulation cover is thus adapted to be wrapped around a structure and secured with the fastener.
The fastener may be formed of a first fastener and a second fastener, each secured to different parts of the insulation cover, the first fastener and second fastener being configured to secure to each other for wrapping the insulation cover around a structure to be insulated.
The coating, which is bonded to the insulation, seals and protects the insulation from damage. The flap prevents moisture from penetrating into a cavity formed by the insulating cover.
The insulation is preferably a closed cell flexible foam material; and the coating is preferably a sprayed on polyurethane polymer coating which possesses the properties of being flexible in a broad range of temperatures yet resistant to puncture.
Further features and advantages of the invention will appear from the description that follows.
BRIEF DESCRIPTION OF THE FIGURES
There will now be described preferred embodiments of the invention, with reference to the drawings, by way of illustration, in which like numerals denote like elements and in which:
FIG. 1 shows a cross-section view of an insulation segment coated with an outer layer, together with a view of a second insulation segment;
FIG. 2 shows a perspective view of insulation segment 14 of FIG. 1, with a strip of tape extending over one edge of the insulation segment;
FIG. 3 shows a perspective view of insulation segment 14 of FIG. 2 with a layer of coating applied over the tape strip and extending onto the first layer of coating;
FIG. 3A shows an insulation segment with a fastener on the inside surface of a flap;
FIG. 4 shows a perspective view of two segments of coated insulation joined by a first strip of tape;
FIG. 5 shows a perspective view of the two insulation segments of FIG. 4 with a layer of coating applied over the tape strip and extending onto the first layer of coating;
FIG. 6 shows a perspective view of an insulation segment with a strip of fiberglass weave cloth applied in position over the coated tape strip;
FIG. 7 shows the embodiment of FIG. 6 in which the fiberglass is covered by coating material; and
FIG. 8 shows an embodiment of the invention wrapped around a structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In this patent document, “comprising” means “including”. In addition, a reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present. A coating is a film of material that covers and bonds to the underlying substrate. When application of a coating is referred to, or reference is made to coating, then this is preferably carried out by spraying of the coating, but may be painted on or applied in other ways such as by dipping the object in a liquid coating bath. The term “removable” when used in this patent document means removable without damaging the insulation cover.
Referring to FIG. 1 there is shown a cross-section of a semi-circular piece of insulation 10 coated with a first protective coating layer 12 thus creating an insulation segment 14 and a second semi-circular insulation segment 16 coated by a first protective coating layer 18 . The preferred choice of insulation is ARMORFLEX™ insulation, which is commercially available from C & I Insulation of Edmonton, Alberta, Canada. The preferred choice of coating material is a polyether polyol such as HYDROSEAL™ polyurethane coating, which is commercially available from Hydroseal Polymers Incorporated, Riverside, Calif. The protective coating material is applied wherever it is deemed necessary to provide mechanical protection to the insulation. In one embodiment, the coating completely covers the insulation on all sides. In another embodiment, one face of the insulation may be left uncoated, with all remaining faces coated. The uncoated face may be the inner concave face of the insulation segment 16 shown in FIG. 1 .
The thickness of the coating may be chosen to suit the intended application. A thicker coating is more durable, but less flexible. The coating should be sufficiently flexible when cured to allow bending of the insulation cover when it is wrapped around a structure. The coating should be resistant against corrosion caused by common industrial fluids such as solvents, hydrocarbons, acids and water. The coating should also be resistant against puncture by protrusions from a structure and resistant against abrasion. Various polymeric resins may be used, preferably polyurethane. Preferred polymeric resins that may be used have similar durability and flexibility as polyurethane.
Referring to FIGS. 2, 3 and 3 A, a strip of tape 20 is applied to surface 22 of insulation segment 14 such that part of the tape overhangs past the edge 42 . The tape is preferably duct tape commercially available from Canadian Tire of Edmonton, Alberta, Canada. A coating layer 24 is applied over a portion of surface 22 and over tape 20 . The coating over the tape 20 creates a flap 26 , and the tape 20 may be removed if desired, leaving the flap 26 . A fastener 25 is attached to the inner surface of flap 26 such as by adhesive. The fastener 25 is selected to mate with a complementary fastener 27 on the outer surface of insulation segment 16 . The fasteners 25 and 27 may be hook and loop type fasteners (Velcro™) or may be any other fastener system that allows the insulation cover to be removably attached to a structure. Examples of detachable fasteners include buttons, zips, cord laced through holes in flaps and large size hook and ring combinations. A single fastener may be used as shown in FIG. 1 . The single fastener may be attached to the surface of an insulated coating for attaching, for example, an insulation cover according to the invention over an opening in a wall. In this case, the wall has a complementary fastener attached to it. The fastener of this example may run around the periphery of a rectangular segment of coated insulation, with the complementary fastener of the wall running around the opening intended to be covered. Flaps 26 with fasteners 25 may be created along all peripheral edges of the insulation cover. Adjacent insulation cover segments are attached to each other by respective fasteners on the flaps to form an interior cavity. The complete unit is wrapped around a structure with the structure in the interior cavity. The flaps protect the interior cavity and the structure from ingress of liquids.
Referring to FIGS. 4 and 5, a strip of tape 28 is applied to surface 22 of insulation segment 14 and surface 30 of insulation segment 16 such that the tape 28 bridges the gap 32 between the two surfaces 22 and 30 . A coating layer 34 is applied over a portion of surfaces 22 and 30 and over tape 28 to create a living hinge. The tape 28 may then be removed. This embodiment is particularly suited to wrapping the insulation cover around a structure 44 as illustrated in FIG. 8 . The segments 14 and 16 are shown as round, but they may be shaped to map the shape of the structure around which they are wrapped. The structure 44 may be any commercial apparatus requiring insulation, such as a valve, flange, tank, pipe or electrical box.
Referring to FIGS. 6 and 7, the insulation cover may be strengthened using fibreglass. A strip of fibreglass weave 38 , may be applied proximately to the tape strip 20 on the surface of coating layer 24 in order to reinforce the flap 26 . A coating layer 40 is applied on top of coating layer 22 and on top of fibreglass weave strip 38 . Alternatively the fibreglass weave strip may be applied proximately next to tape strip 20 prior to the application of coating layer 24 , thus eliminating the requirement for coating layer 40 . Hinge 36 may be reinforced in a similar fashion by following the same procedure as outlined for flap 26 .
Some advantages of the present invention are that the coating layer acts to hold the form of the insulation in the desired shape, protects the insulation from damage due to contact with sharp objects and prevents the insulation from losing its insulation value by preventing the ingress of water. The combination of the insulation coated with the protective outer layer creates a flexible yet durable insulation cover which may be bent without fear of damaging the cover and which may come into contact with sharp protrusions without fear of penetrating the outer covering and thereby exposing the insulation to the elements.
A person skilled in the art could make immaterial modifications to the invention described and claimed in this patent disclosure without departing from the essence of the invention.
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A removable/reusable insulating cover includes an insulating material, a flexible and puncture resistant coating, a flap which is an extension of the coating and a hinge which is an integral part of the coating. The system provides a flexible yet durable insulation cover, which may be removed and reused.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to improvements in nonwoven fabric materials, especially those useful for manufacture of recreational products such as tents, outer wear, tarpaulins and the like. While nonwoven fabrics designed for such purposes have been available, their use has, in general, involved a decision between expensive, sophisticated laminates and simple single layer materials of rather limited utility. Reasons for the rather unsatisfactory choice include the demanding requirements for such a fabric which must be resistant to the passage of water, breathable, and flame retardant while also resistant to degradation by ultraviolet radiation. While much effort has been directed to achieving an optimum combination of these properties in a base material, the results to date have not been entirely satisfactory. For example, it has been found in many cases that treatments for flame retardancy and resistance to degradation by ultraviolet radiation detrimentally affect each other with the result that a compromise in these properties is necessary. In addition, it is desirable to provide such materials on a more economic basis while retaining beneficial properties. Therefore, the need persists for an improved nonwoven fabric especially intended for recreational uses.
2. Description of the Prior Art
Representative of prior art materials described generally above include those disclosed in U.S. Pat. No. 4,194,041 to Gore et al. dated Mar. 18, 1980. These laminates include a combination of a hydrophilic interior interfacing layer and a hydrophobic outer layer. Examples of the former include perfluorosulfonic ion exchange membranes and an example of the latter is polytetrafluoroethylene sheeting. Such materials are relatively costly, and the patent contains no disclosure of ultraviolet radiation degradation or flame retardancy results. U.S. Pat. No. 4,041,203 to Brock et al. issued Aug. 9, 1977 discloses laminates of spunbonded and meltblown nonwovens including a suggestion that such laminates may be useful for a wide variety of applications including outer wear linings, jackets, rainwear, pillow cases, sleeping and slumber bags and liners. The patent further suggests that water repellency and air permeability are attained and that pigments may be added for desired color effects. However, the patent does not disclose treatments for flame retardancy and ultraviolet radiation degradation resistance. U.S. Pat. No. 4,196,245 to Kitson et al. dated Apr. 1, 1980 also discloses laminates of spunbonded and meltblown nonwovens having liquid strike-through resistance and air permeability. U.S. Pat. No. 3,932,682 to Loft et al. dated Jan. 13, 1976 describes recreational fabric material having a capability of transmitting air and moisture vapor and being waterproof made by spray spinning a filamentary polymer material onto open-celled polymer film or noncellular elastic polymer film having been stretched and heat set. U.S. Pat. No. 4,217,386 to Arens et al. dated Aug. 12, 1980 describes laminates of meltblown and spunbonded webs with an activated carbon layer for garments to protect against toxic chemical vapors. U.S. Pat. No. 4,196,245 to Kitson et al. dated Apr. 1, 1980 describes a wide variety of laminates including at least two meltblown layers particularly useful for surgical applications. In addition, there are a great number of prior art patents describing processes for attaining one or more of the desired properties of flame retardancy, ultraviolet radiation degradation resistance, water repellency, and the like. Representative of these are U.S. Pat. No. 4,094,943 to Howarth et al. issued June 13, 1978, U.S. Pat. No. 3,955,028 to Weil issued May 4, 1976, U.S. Pat. No. 3,955,029 to Garner issued May 4, 1976, U.S. Pat. No. 4,035,542 to Rosenthal et al. issued July 12, 1977, U.S. Pat. No. 4,219,605 to Rohringer issued Aug. 26, 1980, U.S. Pat. No. 4,154,890 to Wagner issued May 15, 1979, U.S. Pat. No. 4,158,077 to Mischutin issued June 12, 1979, U.S. Pat. No. 4,178,408 to Franz et al. issued Dec. 11, 1979, U.S. Pat. No. 3,928,504 to Koelewijn issued Dec. 23, 1975, and U.S. Pat. No. 3,678,136 to Vandenberg issued July 18, 1972.
SUMMARY
The nonwoven recreational fabric of the present invention, in its most basic form, comprises a three layer laminate. The outer layers are spunbonded nonwovens, one of which is treated for resistance to ultraviolet radiation degradation and is intended for outside exposure. The other spunbonded layer is treated for flame retardance and ultraviolet degradation resistance. The middle layer is a meltblown nonwoven which may or may not contain a ultraviolet stabilizer and is preferably densified and contributes resistance to liquid strike-through. The resulting fabric, unexpectedly, has a combination of properties exhibiting a higher degree of flame retardance and resistance to ultraviolet light degradation than the individual treated components. Thus, instead of these treatments adversely affecting each other as had been prior experience, they cooperate in a positive manner to produce a fabric having improved properties.
The combination preferably includes pigments for coloring the spunbonded webs and may include additional layers of either spunbonded or meltblown materials depending upon the desired physical properties. Bonding of the laminate is preferably achieved in a pattern to retain flexible, fabric-like feel and hand. For example, heat and pressure in a patterned nip may be applied, or ultrasonic spot welding may be employed. The resulting fabrics are highly useful as tent material and for other recreational applications including outerwear, tarpaulins, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a three layer nonwoven fabric of the present invention shown partially broken away;
FIG. 2 is a similar view of an alternative embodiment employing more than three layers;
FIG. 3 is a perspective view of the fabric of FIG. 1 illustrating a representative pattern bond configuration.
FIG. 4 is a cross-section of the web of FIG. 2 taken along lines 4--4; and
FIG. 5 is a schematic illustration of a method of making the fabrics of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
In describing the nonwoven fabrics of the present invention and their properties, reference to certain tests will be made. These tests are described as follows:
Trapezoidal Tear
Federal Test Method Standard No. 191B Method 5136 was employed with the exceptions that, the face of the jaws measured 1 inch by 3 or more inches, the distance between clamps was 1 inch at the start of the test, and all machine attachments for determining maximum loads were disengaged during testing. A sample 3 inches by 6 inches was used and a cut of about 3/8 inch made in the center of a perpendicular to the shorter base of an isosceles trapezoid having an altitude of 3 inches and bases of 1 and 4 inches marked on the sample.
Water Repellency
Federal Test Method Standard No. 191B Method 5514 was employed using an inverted conical well equipped to introduce water at 26.7° C. above the sample over a circular area of 4.50±0.05 inches in diameter at a rate of 1±0.1 centimeters of hydrostatic head per second.
The sample was clamped over the inverted conical well orifice and water introduced with the air vented. The hydrostatic head was measured to the nearest centimeter at the appearance of a drop or drops of water at three different locations and the average of five readings reported.
Elmendorf Tearing Resistance
Federal Test Method Standard No. 191B Method 5132 was employed using a pendulum machine wherein a 21/2 by 4 inch specimen was held between a pair of clamps, one movable and one stationary and torn by the fall of a pendulum through the force of gravity. A circumferential graduated scale indicated the force used in tearing the specimen. The sample is clamped with the long dimension parallel to the machine direction for machine direction tests and parallel to the cross direction for cross direction tests.
A slit was formed in the specimen midway between the clamps extending from the bottom edge of the specimen to a point 0.157 inch above the top edge of the clamps leaving a distance of 1.692 inches of un-cut specimen perpendicular to the long dimension of the specimen. With the pendulum in the raised position the moveable clamp lies in the same plane as the fixed clamp forming an extension of the fixed clamp. When the pendulum fell, the pendulum clamp moved away from the fixed clamp tearing the specimen. The force required to tear was read from a scale to the nearest division. Five tests were made and the results averaged.
Flame Resistance of Cloth; Vertical
Federal Test Method Standard No. 191B Method 5903 using a rectangular specimen 23/4 inches by 12 inches. All samples were brought to moisture equilibrium under standard atmospheric conditions and exposed to a test flame within 20 seconds after removal. The sample was suspended vertically so that the entire length of the specimen was exposed and the lower end 3/4 inch above the top of the gas burner. Prior to inserting the specimen the pilot flame was adjusted to approximately 1/8 inch in height from its fullest point to the tip. The burner flame was adjusted by means of a needle valve to give a flame height of 11/2 inches with the stop cock fully open and the air supply shut off and taped. After inserting the specimen, the stop cock was fully opended and the burner flame applied vertically at the middle of the lower edge of the specimen for 12 seconds and the burner turned off. The after-flame time was recorded as the time the specimen continued to flame after the burner flame was shut off. The after-glow time was the time the specimen continued to glow after it had ceased to flame.
Water Vapor Permeability
This test was determined in accordance with Federal Test Method Standard No. 406 dated Oct. 5, 1961, identified as Method 7032.
Permeability to Air; Cloth, Calibrated Orifice Method
This method was conducted in accordance with Federal Test Standard No. 191B Method 5450 dated Dec. 31, 1968 and used a square sample having a minimum of 7 inches by 7 inches.
Turning to FIG. 1, the nonwoven fabric laminates of the present invention will be described in further detail. As illustrated, laminate 10 comprises spunbonded layers 12 and 14 on either side of meltblown layer 16. Spunbonded layer 10 is preferably formed with spotbonds 15 in accordance with the process described in U.S. Pat. No. 3,855,046 to Hansen et al. issued Dec. 17, 1974, incorporated herein by reference. The basis weight of this component is preferably in the range of from about 0.5 to 5 oz/yd 2 with the range of 1 to 3.5 oz/yd 2 being most preferred. As will be recognized by those skilled in the art, ultraviolet radiation resistance to degradation may be obtained in such spunbonded webs by a number of means. For example, the webs may be coated with an agent for that purpose, or the agent may be incorporated into the polymer prior to extrusion. For purposes of this invention, it is preferred that the latter method be utilized and that an agent selected from the group consisting of nickel chelates such as nickel (2,2' thiobis (4 tertiary octyl) phenolato) normal butylamino, and bis (2,2' thiobis-4-(tertiaryoctyl) phenolato) nickel or the group consisting of hindered amines be employed. Use of this agent in an amount in the range of from about 0.25 to 2.0% based on the weight of polymer is preferred.
Spunbonded layer 14 is preferably similarly prepared except that a flame retardancy agent is employed in addition to the agent designed to provide ultraviolet radiation degradation resistance. Such flame retardancy agents are also known and may be added by coating, impregnating, or in the polymer prior to extrusion. The latter step is also preferred using an agent such as aromatic bromine compounds in combination with antimony trioxide or pentavalent antimony oxide in an amount of up to about 2-20% by weight of polymer.
Meltblown layer 16 is preferably formed in accordance with the disclosure of U.S. Pat. No. 3,676,242 to Prentice issued July 11, 1972 or such as described in an article entitled "Superfine Thermoplastic Fibers," appearing in Industrial Engineering Chemistry, Vol. 48, No. 8, pages 1342 to 1346 which describes work done at the Naval Research Laboratories in Washington, D.C. Also see Naval Research Laboratory Report 11437, dated Apr. 15, 1954. Preferably this component has a basis weight in the range of from about 0.5 to 2.0 oz/yd 2 and especially 0.5 to 1.25 oz/yd 2 . Such materials are highly advantageous in providing resistance to liquid strike-through while allowing the passage of water vapor and air. The stability of this meltblown component can be improved by the utilization of ultraviolet degradation stabilizers as in the case of the spunbond components.
Any or all of the component layers may be colored by the addition of pigments to the polymer prior to extrusion. Preferably the outer layers are colored differently so as to distinguish easily between the treatments applied for resistance to ultraviolet light radiation degradation and fire retardancy. The total basis weight of the combination is preferably in the range of from about 2.5 to 10.0 oz/yd 2 for most recreational fabric applications and especially in the range of from about 3.0 to 8.0 oz/yd 2 for applications such as tent material.
While a number of synthetic thermoplastic polymers may be employed in forming the component layers of the present invention, for improved bonding of the laminate, it is preferred that the same polymer be employed in each of the component layers or, at least, polymers having similar melting points. Especially preferred is polypropylene, but other synthetic thermoplastic polymers such as polyethylene, polyester, nylon, and the like may be employed as well. However, as is known, selection of a specific polymer may dictate changes in the selected treatment agents as well as bonding conditions for the laminate. These changes, however, will be apparent to those skilled in the art familiar with the manufacture of nonwovens from such polymers.
As shown in FIG. 2, additional component layers may be employed for the purpose of obtaining specific properties such as increased strength or the like. As illustrated, nonwoven fabric 18 includes spunbonded layers 20 and 22 on the exposed surfaces as well as meltblown layer 24 and the additional spunbonded layer 26 as intermediate layers. In this case, spunbonded layer 26 need not be treated and provides additional supporting strength for the laminate intended for heavy duty applications such as tarpaulins and the like.
FIG. 3 illustrates a pattern bonded three component fabric of the present invention that has been pattern bonded by means of heat and pressure. The pattern bonding 28 preferably occupies an area of 5 to 20% of the surface and incorporates a bond density of about 10 to 40 pins/in 2 .
FIG. 4 is a cross-section at lines 4--4.
Turning to FIG. 5, a method of forming the combination of FIG. 3 will be described. Spunbonded web 14 is unwound from supply roll 30 onto support belt 42 driven about rolls 44, 46. Meltblown web 16 is formed directly onto web 14 by die 48. A second spunbonded web 12 is unwound from parent roll 50, and the three layers directed through combining nip 52 between rolls 54, 56. The combination is pattern bonded by passing between sonic horn 58 and anvil roll 60 into fabric 62.
The invention will now be further described in terms of specific examples demonstrating the range and improved properties obtained.
EXAMPLE 1
A spunbonded component layer was formed in accordance with the process described in aforementioned Hansen et al. U.S. Pat. No. 3,855,046. Specifically, polypropylene having a melt flow at 230° C. generally in the range of from 30 to 40 g/10 min. (available from Hercules under the trademark Profax) was extruded at a rate of 0.9 g/min. and at a temperature of about 230° C. and drawn to form continuous filaments having an average diameter of about 15 microns. These filaments were collected on a support into an entangled web having a basis weight of 2 oz/yd 2 . Prior to extrusion Cyasorb 1084 (2,2' Thiobis (4-t-octyl phenolato)-n-butyl amine Nickel II from American Cyanamid) and Tinuvin 328 (benzotriazote type ultroviolet stabilizer were added to the polymer in an amount of 0.75% each based on polymer weight for ultraviolet radiation resistance, and a fiber grade pigment dispersion was added to the polymer in an amount of 4% based on polymer weight for color. The mixture was blended until thoroughly mixed at room temperature in a tumble mixer. This component layer was pattern bonded by passing through a nip between a patterned steel roll and a smooth anvil roll at a temperature of 310° F. and pressure of 400 p.l.i. This resulted in 107 bonds per square inch and individual diamond shaped bond areas of 14.5% overall coverage.
A second spunbonded component layer having a basis weight of 2 oz/yd 2 was formed in the same manner except that, prior to extrusion, decabromodiphenyl oxide/antimony trioxide, 3:1 ratio mixture was added to the composition as a flame retardant in the amount of 8% by weight based on the polymer.
A meltblown component layer was formed in accordance with U.S. Pat. No. 3,676,242 to Prentice. Specifically, polypropylene having a melt flow at 230° C. in the range of from 30 to 40 g/10 min (available from Hercules under the trademark Profax) was meltblown at a rate of 3.3 lbs/inch/hour into discontinuous filaments having an average diameter of about 1.5 microns. These filaments were collected on a support into an entangled web having a basis weight of 1.0 oz/yd 2 .
The three component layers were combined by passing between a sonic horn and an anvil. The resulting combination was overall pattern bonded as illustrated schematically in FIG. 6. The combination was subjected to tests as shown in Table I. For comparative purposes conventional recreational fabrics were also tested.
EXAMPLE 2
Example 1 was repeated except that the basis weight of the component layers was as follows: first spunbonded layer 3 oz/yd 2 , second spunbonded layer 3 oz/yd 2 , and meltblown layer 1 oz/yd 2 for a combined basis weight of 7 oz/yd 2 .
EXAMPLE 3
Example 1 was repeated except that 0.75% by weight of a ultraviolet stabilizer (available from American Cyanamid under the trademark Cyasorb 2908) was added to the meltblown polymer prior to extrusion for ultraviolet light resistance.
TABLE I__________________________________________________________________________Physical Tests Moisture Elmendorf Trap. Tear Hydro. Air VaporTest Basis Wt. Tear (lbs) (lbs) Head Perm. Trans.Sample oz/yd.sup.2 MD XD MD XD (cm) (cfm) (g/m.sup.2 /24 hrs)__________________________________________________________________________Example 1 5 5 5 20 20 58 26 8000Example 2 4 4 4 18 18 55 28 8000Cotton Poplin 7 2.5 2.9 10.0 4.3 26 3 420050/50 Polyester/ 5.5 1.8 3.0 2.9 3.9 26 0 --CottonPolyester 5.0 2.0 2.3 13.0 9.0 30 0 500__________________________________________________________________________
TABLE II__________________________________________________________________________Exposure Tests Water Hydrostatic Repellency Head RetainedTest Retained % Initial Mildew Development Days* ExposureSample After 120 Days* (cm) 120 Days Initial 30 60 90 120 150__________________________________________________________________________Example 1 40 50 20 None None None None None NoneExample 3 98 51 50 -- -- -- -- -- --Cotton Poplin -- -- -- None None None Slight Moderate Heavy(7 oz/yd.sup.2)__________________________________________________________________________ *South Florida Test Fence Exposure
As these tests demonstrate, recreational fabrics of the present invention have improved combinations of properties including physical properties and properties after exposure. Particularly when ultraviolet resistant meltblown webs are used, hydrostatic head retention upon ageing is highly improved. When compared to conventional fabrics combinations of such properties are highly beneficial.
As the above examples demonstrate, the nonwoven fabric of the present invention provides a combination having highly improved properties when compared with the individual component. Thus, instead of providing counteracting treatments, the multi-component fabrics enhance the properties of the individual components and provide an improved overall result. Such fabrics are highly useful, especially for recreational fabric applications including tents, outer wear, tarpaulins and the like.
Thus, it is apparent that there has been provided, in accordance with the invention a nonwoven fabric laminate that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
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Laminate of nonwoven fabric having unique properties suitable especially for use as a recreational fabric in the manufacture of tents, outer garments, tarpaulins and the like. The laminate includes, as essential components, an outer spunbonded layer treated for resistance to ultraviolet radiation and intended as the exposure surface, an inner microporous meltblown layer, preferably densified for resistance to liquid strike-through, and, on the unexposed surface, another nonwoven layer treated for flame retardancy. The combination optionally includes additional pigments in the exposed surface layers for desired appearance as well as pigments and/or ultraviolet radiation resistance treatment in the inner meltblown layer. As additional options, further layers of meltblown or spunbonded nonwovens may be included to attain desired physical properties. The resulting material provides a unique combination having excellent properties for recreational fabric uses, especially water repellency, breathability, resistance to degradation by ultraviolet radiation and flame retardancy.
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BACKGROUND OF THE INVENTION
The present invention relates to a robot for automatically removing an unnecessary portion on a workpiece.
In relation to the path instruction for a robot, for example, a technique disclosed in Japanese Patent Unexamined Publication No. 2-257310 has conventionally been known. With this technique, path instruction data are produced by manual operation of a teaching box. Alternatively, the robot is operated through manual guidance with a hand of an operator so that a tool will take a desired posture corresponding to a required position, and displacement positional data are collected from actuators in the robot, thereby producing path instruction data from the collected displacement positional data.
In relation to correction in accordance with a displacement of an operation object, for example, a technique is disclosed in Japanese Patent Unexamined Publication No. 2-274490. With this technique, corrections of positional and rotational displacements of a workpiece to be machined (an operation object) are conducted promptly. More specifically, a reference point is set on the workpiece, and amounts of the positional and rotational displacements of the workpiece on the robot coordinate system are obtained promptly on the basis of a difference between a positional vector of the reference point when there is no displacement and a positional vector of the reference point when there is a displacement.
Further, a technique in which a robot instruction position is defined on the basis of diagram information produced in a CAD system is disclosed in Japanese Patent Unexamined Publications Nos. 63-58505, 61-175775 and so forth. In this technique, the instruction position on a workpiece, which is a result of off-line definition from CAD data, is corrected on the basis of a positional displacement of the actual workpiece viewed from a camera. Moreover, Japanese Patent Unexamined Publication No. 63-273912 discloses a technique in which instruction data are produced from a robot, an object to be machined, a jig and so on while performing operational simulation of the robot, and the data are finally transformed into a robot language. Also, Japanese Patent Examined Publication No. 3-34086 discloses a technique in which a welding robot performs arc welding while vibrating a welding torch in a bevel widthwise direction, and detects and modifies a positional displacement of the welding torch during the vibration, and particularly, a method of operating the welding torch following an arcuate welding line.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a robot for automatically removing an unnecessary portion on a workpiece, which can precisely maintain a position and/or a posture of a tool for removing the unnecessary portion with respect to the unnecessary portion.
The invention provides a robot for removing an unnecessary portion on a workpiece, which comprises: a tool for removing the unnecessary portion; tool positioning means which contain a reference coordinate system, carry the tool attached thereon, and is movable to change a position and a posture of the tool in the reference coordinate system; jig means on which the workpiece is securely fixed to maintain a desired position and a desired posture of the workpiece with respect to the reference coordinate system of the tool positioning means; and arithmetic means for calculating a movement path and a posture of the tool moved by the tool positioning means on the basis of a position of the unnecessary portion on a desired shape of the workpiece, in which the arithmetic means correct the movement path and the posture of the tool in accordance with a shape or condition of at least one of the workpiece, the tool and the jig means other than the position of the unnecessary portion on the desired shape of the workpiece.
According to this invention, the movement path and the posture of the tool calculated on the basis of the position of the unnecessary portion on the desired shape of the workpiece are corrected in accordance with a shape or condition of at least one of the workpiece, the tool and the jig means other than the position of the unnecessary portion on the desired shape of the workpiece. Therefore, the position and/or posture relation between the tool and the unnecessary portion on the workpiece can be maintained at a desirable level, and the unnecessary portion can be removed by the tool precisely.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view showing a robot according to the present invention;
FIG. 2 is schematic perspective views showing workpieces from which unnecessary portions are removed by the robot according to the invention;
FIG. 3 is a conceptional view illustrative of a schematic chart of software for controlling the robot according to the invention;
FIG. 4 is a part of a CL file in which a position of an unnecessary portion on a workpiece and an access path of a tool toward the unnecessary portion are specified on a designed shape which is read out of a CAD system through a tool path defining program;
FIG. 5 is a part of a robot operation information file in which an unnecessary portion whose position is specified and a specified access path of a tool toward the unnecessary portion are divided into sections through a robot operation determining program, and positions of ends of the division sections are expressed in the form of sequences of points;
FIG. 6 is a flow chart illustrative of the schematic chart of software shown in FIG. 3;
FIG. 7 is a schematic diagram illustrative of a relation between a moving direction of a tool and a directional vector used for controlling the robot according to the invention when the tool is determined to be moved on a straight line;
FIG. 8 contains schematic diagrams illustrative of a relation between a position of contact between a tool and an unnecessary portion and a directional vector used for controlling the robot according to the invention when the tool removes the unnecessary portion;
FIG. 9 is a schematic diagram showing that, in this invention, when a tool is moved on a curved movement path, the movement path is divided into sections, and each of the sections contains ends where the tool passes;
FIG. 10 is a schematic diagram showing a directional vector used for controlling the robot according to the invention when a tool is moved on both of a curved movement path and a straight movement path continuously;
FIG. 11 is a schematic diagram showing a directional vector used for controlling the robot according to the invention when a tool is moved on both of a curved movement path and a straight movement path continuously;
FIG. 12 is a schematic diagram illustrative of specification of a point on a curved movement path where a tool first passes, on the basis of a directional vector expressing an advancing direction of the tool when the tool is located on a straight movement path in the case where the tool is moved from the straight movement path to the curved movement path;
FIG. 13 contains schematic diagrams illustrative of classification of a point on a curved movement path on the basis of a coordinate system having a coordinate axis which contains a boundary point between a straight movement path and the curved movement path in the case where the tool is moved from the straight movement path to the curved movement path;
FIG. 14 is a schematic diagram illustrative of rotational correction of a coordinate system having a coordinate axis which contains a boundary point between a straight movement path and a curved movement path when the coordinate system having the coordinate axis which contains the boundary point between the straight movement path and the curved movement path is rotated with respect to a coordinate system of a workpiece in the case where the tool is moved from the straight movement path to the curved movement path;
FIG. 15 is a schematic diagram illustrative of a relation between a directional vector expressing a posture of a tool and a point on a curved movement path where the tool must pass, which relation is required for controlling a robot;
FIGS. 16(A) and 16(B) are schematic diagrams illustrative of specification of a moving direction of a tool in the case where the tool is moved to a curved movement path without passing a straight movement path;
FIG. 17 is a schematic diagram illustrative of the case where a directional vector expressing a moving direction of a tool on a straight movement path is different from a directional vector expressing a moving direction of the tool at a starting point of a curved movement path, and the case where a directional vector expressing a moving direction of the tool on a curved movement path is different from a directional vector expressing a moving direction of the tool at a starting point of a straight movement path;
FIG. 18 is a schematic diagram showing a boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece (i.e., a virtual movement path of a tool or a desired designed shape of the workpiece);
FIG. 19 is a schematic diagram illustrative of interpolation, with a cubic function curve, between two adjacent points on a curved movement path where a tool must pass;
FIG. 20 is a schematic diagram showing that, in order to obtain an appropriate coefficient of a cubic function curve interpolated between two adjacent connecting points on a curved movement path where a tool must pass, tangent lines of two adjacent cubic function curves are identical with each other at each of the connecting points;
FIGS. 21 (A), 21 (B) and 21 (C) are schematic diagrams showing various tools used in the invention;
FIG. 22 is a schematic diagram illustrative of a relation between a boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece (i.e., a virtual movement path of a tool or a desired designed shape of the workpiece) and an actual movement path of the tool;
FIG. 23 is a schematic diagram illustrative of a relation between a boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece (i.e., a desired designed shape of the workpiece), and an actual movement path and an actual posture of a tool;
FIG. 24 is a schematic diagram illustrative of a relation between a directional vector expressing a posture of a tool and an actual posture of the tool, which relation is required for controlling a robot;
FIG. 25 is a schematic diagram illustrative of relations between a coordinate system of a surface of a workpiece including an unnecessary portion to be removed, a coordinate system of the whole workpiece, a coordinate system of a surface of a jig on which the workpiece is securely fixed, and a coordinate system of the whole jig;
FIG. 26 is a schematic diagram illustrative of one example of numbering for specifying a position of the jig surface with respect to the whole jig and a position of the surface including the unnecessary portion with respect to the whole workpiece;
FIG. 27 contains schematic diagrams illustrative of a relation between the jig surface coordinate system and the whole workpiece coordinate system when a plurality of workpieces are securely fixed on the jig surface;
FIG. 28 is a schematic flow chart illustrative of operation of a robot when the robot measures an actual shape of a workpiece;
FIG. 29 is a block diagram showing a schematic chart of a robot for measuring an actual shape of a workpiece;
FIG. 30 is a block diagram illustrative of calculation of a movement path of a tool (i.e., a course along an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece) on the basis of a measured actual shape of the workpiece and a position of the unnecessary portion which is specified on a desired shape of the workpiece (i.e., a course along a specified boundary on the workpiece between the unnecessary portion to be removed and the rest of the workpiece);
FIG. 31 is a schematic diagram illustrative of calculation of an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece on the basis of a measured actual position of one point on the workpiece;
FIG. 32 is a schematic diagram illustrative of calculation of an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece on the basis of measured actual positions of two points on the workpiece;
FIG. 33 is a diagram for explaining a principle when calculating an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece on the basis of measured actual positions of two points on the workpiece and a specified boundary on the workpiece between the unnecessary portion to be removed and the rest of the workpiece (i.e., a specified position of the unnecessary portion on a desired shape of the workpiece);
FIG. 34 is a schematic diagram illustrative of calculation of an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece on the basis of measured actual positions of three points on the workpiece;
FIG. 35 is a diagram for explaining a principle when calculating an actual boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece on the basis of measured actual positions of three points on the workpiece and a specified boundary on the workpiece between the unnecessary portion to be removed and the rest of the workpiece (i.e., a specified position of the unnecessary portion on a desired shape of the workpiece);
FIG. 36 is a schematic perspective view showing a directional vector expressing a posture of a tool which is required for controlling of a robot when dividing a specified boundary on a workpiece between an unnecessary portion to be removed and the rest of the workpiece (i.e., a specified position of the unnecessary portion on a desired shape of the workpiece or a path where the tool passes to remove the unnecessary portion on the workpiece) into a plurality of sections, interpolating a cubic curve between opposite ends of each of the division sections, and controlling the robot on the basis of a plane defined by one point of a surface of the desired shape of the workpiece in the vicinity of each of the plurality of sections and the opposite ends of the division section, and the cubic interpolation curve;
FIG. 37 shows coefficients of the cubic curves shown in FIG. 36 and directional vectors expressing normal lines on the plane which is defined by one point on the surface of the desired shape of the workpiece in the vicinity of each of the plurality of sections and the opposite ends of the division section; and
FIG. 38 is a schematic perspective view illustrative of rotation of a directional vector expressing a posture of a tool for forming a surface of a workpiece inclined at a desired angle with respect to a coordinate system which defines a desired shape of the workpiece.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Workpieces to be machined by a robot according to the present invention will be described first. FIG. 2 shows examples of workpieces having free curved portions. In the drawing, ridgelines (lines where planes intersect) or holes of workpieces which are denoted by reference numerals 4 are portions where burrs (unnecessary portions) are formed. The invention will be fully explained with reference to a method of producing robot path data for removing burrs 4 shown in FIG. 2. FIG. 1 is an outer-appearance schematic view showing a burr removing robot, a controller for controlling the robot, a CRT, an input means and so forth. Robot path data used in this invention are inputted to the robot controller 2 by the input means 3, and the robot controller 2 operates the robot 1 on the basis of the robot path data inputted thereto. When a CPU of the robot controller 2 receives various kinds of input signals such as a robot start signal, the CPU controls the robot in accordance with a program stored in a program memory. This system includes a CRT for checking the input data and the output data of various kinds. A burr removing tool 5 is attracted, by air suction, to a distal end of a hand of the robot 1. Among tools of several kinds which are stored in a tool container (not shown), a desired one can be selected. A workpiece to be machined 6 is attached to a jig 7 which is 360° rotatable about the Z axis, and the origin of the jig coordinate system and the origin of the robot coordinate system are positioned accurately to have a certain relative positional relation.
Next, a data producing system mechanism for performing robot path definition will be described. FIG. 3 is a conceptional view illustrative of its schematic entire chart. In a CAD system 8, a diagram of a workpiece to be machined is drawn, and stored in a diagram file 9.
On the basis of data of the workpiece diagram stored in the diagram file g, a tool path defining program 11 determines a portion of a workpiece 6 where a tool (e.g., a grinder) 5 should remove burrs. This determination is conducted by displaying the workpiece diagram on the CRT and determining areas or line segments where burrs are formed on the workpiece diagram by means of a mouse or the like. A path of the tool (i.e., a course along a boundary between an unnecessary portion of a workpiece to be removed and the rest of the workpiece) is divided into a plurality of straight sections and arcuate sections. At this time, not only the portions of the workpiece from which burrs will be removed but also ways of operating the tool (moving the robot) before and after the burr removal are determined while referring to the graphic image. Also, a command for determining machining conditions such as coordinate transformation information, target chamfering angles, the tool numeral, and virtual compliance parameters (a viscosity constant C, a spring constant k, a mass m) is added to the determined information for indicating the areas or line segments where burrs are formed. Thus, a CL (Cutter Location) file shown in FIG. 4 is produced.
In this CL file, a command is written on each line, and its left portion separated from the rest by a slash `/` expresses the function of the command and is referred to as the subject.
The right portion serves as the predicate and is composed of terms for defining the function in detail. Since the above-mentioned coordinate transformation information, virtual compliance parameters, positioning of the grinding tool, and target chamfering angles are additional information, for example, `INSERT` is written as the subject, and `JIGU`, `JFACE`, `PFACE` and `PARTS NUM` for coordinate transformation information, `VCSET` for virtual compliance parameters, `CUTSIDE` for positioning of the grinding tool, `CUTANGLE` for target chamfering angles, are written as the predicate. As the coordinate transformation information, relations between a jig coordinate system, a jig surface coordinate system, a workpiece coordinate system, and a workpiece surface coordinate system must be defined. Consequently, the coordinate systems are referred to as `JIGU`, `JFACE`, `PFACE` and `PARTS NUM`, respectively. Each of these coordinate systems includes a plurality of coordinate systems having different origins or the same origin, and the plurality of coordinate systems are discriminated from one another by numbering. For example, selection of a coordinate system of the jig surface which is one element of the jig surface coordinate system and designated by No. 1 is inputted to the CL file by writing as follows:
INSERT/JFACE
INSERT/1
`INSERT/1` in the second line expresses the matter which further specifies `INSERT/JFACE` in the first line. Similar specifications are carried out in relation to the jig coordinate system, the workpiece coordinate system, and the workpiece surface coordinate system. The command for the workpiece coordinate system is `PARTS NUM` because the workpiece coordinate system is concerned with inputting the number of workpieces. That is to say, when the number of workpieces is three, it means that attachment positions of three workpieces on the jig are predetermined, and that the workpieces respectively correspond to a plurality of coordinate systems which constitute the workpiece coordinate system. The command (E) of FIG. 4, which expresses a virtual compliance parameter for power control by means of a certain unit numeral, determines Unit No. 1, for example. The command (F) of FIG. 4 determines, in the subsequent line, 1 when grinding is effected on the right with respect to the advancing direction, and 0 when grinding is effected on the left with respect to the advancing direction. The command (G) of FIG. 4 expresses that a target surface chamfering angle is 45°.
A straight section of a free curve indicating a position of an unnecessary portion (a boundary between a portion to be removed and the rest of the workpiece) is expressed in the command (H) of FIG. 4 as follows:
GOLFT(LINE)/72.104127, -40.0, -48.0
The three values express coordinate values in the x, y and z directions from the origin of the diagram, specifying that a grinding portion of the tool in contact with the workpiece so as to remove the unnecessary portion is moved straight 72.104127, -40.0 and -48.0 (the unit is, e.g., mm) in the x, y and z directions, respectively, from the present position (the point where it has already reached). An arcuate section is expressed in the commands (I) to (K) as follows:
GOLFT(ARC)/22.945260, -58.493145, -48.0
Center=(27.773075, -50.897606, -48.0)
radius=9.0
They specify that the grinding portion of the tool is moved along an arc having a radius of 9.0 around the center (x=27.773075, y=-50.897606, z=-48.0) from the present position to a target position of x=22.94526, y=-58.493145, z=-48.0.
Next, a robot operation information file 14 is produced on the basis of CL data 12 through a robot operation determining program 13.
In the robot operation determining program 13, if a straight line is formed by the position of an unnecessary portion on the workpiece (a boundary between a portion to be removed and the rest of the workpiece, i.e., the path of the grinding portion of the tool) which is determined in the tool path defining program 10, a starting point and a terminal point of the straight line are automatically determined, and if an arc is formed, the path of the grinding portion of the tool is divided into a plurality of sections, and passing points on both each of these sections where the grinding portion of the tool must pass are automatically determined. Thus, the tool path is changed into a sequence of points and stored in the robot operation information file 14. Moreover, when it is changed into a sequence of points in the robot operation determining program 13, the robot not only is operated to move the tool but also must control the power for pressing the tool on the workpiece during actual burr-removal operation. Therefore, attribute data of the passing points are added about whether the tool passes each of the passing points while it is grinding (CUT) or while it is moving (MOVE), and also, attribute data of the passing points are added about whether each of the passing points is a point on the arc or not. FIG. 5 shows an example of such data writings.
A numeral written immediately after `CUT` or `MOVE` denotes the number of points. Further, in the case of `CUT`, 0 and 1 in the subsequent line express whether the points are on a straight line or on an arc. 0 and 1 in the next line express whether or not the points must be corrected in accordance with the tool.
Moreover, FIG. 5 shows that until the burr removal position in the tool path, the tool is first moved to a position (Px, Py, Pz) with a direction vector (Fx, Fy, Fz), (Gx, Gy, Gz), (Hx, Hy, Hz) indicating the posture of the tool.
In addition to the data inputted through the robot operation determining program 13, the coordinate transformation information, target chamfering angles, a shape, a size and an inclination angle of the tool to be used, the tool numeral, virtual compliance parameters for power control, and the attachment position of the jig, which are inputted through the tool path definition program 10, are stored, as data, in the robot operation information file 14.
In a robot operational language output program, on the basis of these data in the robot operation information file, a movement path of the origin of the tool is calculated from the position of the unnecessary portion (i.e., the path of the grinding portion of the tool) specified on the workpiece diagram which is data in the CL file, in comparison with data in a tool information file which indicate a shape of the grinding portion of the tool and a positional relation between the attachment position of the tool on the robot surface (the origin of the tool) and the grinding portion of the tool. While a tool movement speed and so forth are automatically determined, the data are transformed into coordinates in a robot coordinate system and outputted to a robot command file.
The above-described processing flow is shown in FIG. 6.
In Step 1, a diagram of a workpiece to be machined is first drawn in the CAD system 8.
Next, in Step 2, the data of the workpiece diagram stored in the diagram file 9 are displayed on the CRT, and the tool path (the path of the grinding portion of the tool) is defined through the tool path definition program 10 by determining, by means of a mouse or the like, areas and line segments corresponding to the boundary between the unnecessary portion to be removed by the tool (e.g., a grinder) 5 and the rest of the workpiece in the workpiece diagram which shows a shape of the workpiece 6.
In Step 3, information other than the tool path defined from the diagram information of the workpiece is required for actually performing the burr removal operation through operational instruction to the robot 1. For example, when burrs are removed from the workpiece 6, a reaction force exerted on a power sensor which is attached on the tool 5 of the robot 1 is detected to effect virtual compliance control of a grinding force as a grinder torque, a feed speed of grinder rotation and so forth. Compliance parameters such as a viscosity constant C, a mass M and a spring constant K, target chamfering angles, and machining conditions such as the tool numeral which can specify information of the tool actually used such as the shape and the size, are added to the tool path data.
In Step 4, the CL file 10 is produced on the basis of the tool path defined in Step 2 and the machining condition information added in Step 3.
In Step 5, if the region on the workpiece (the tool path) which is specified in Step 2 is a straight line, a starting point and a terminal point of the straight line are automatically determined, and if it is an arc, a plurality of passing points which divide the arc into a plurality of sections are automatically determined. Thus, the tool path is changed into sequences of points, and coefficients of cubic functions expressing curves which are interpolated between the sequences of passing points are determined. This interpolation algorithm will be described later.
In Step 6, each of the passing points is discriminated whether the tool passes it while grinding (CUT) or while moving (MOVE), and the results are stored as attribute data of the passing points.
In Step 7, since the tool path (the path of the grinding portion of the tool) determined until Step 6 can be regarded as a course of a point of intersection between a rotational axis of the burr removing tool 5 and the workpiece (hereinafter referred to as a virtual center point O 1 ), as shown in FIG. 16, correction is performed in accordance with a diameter of the tool 5, and an angle for inclining the tool 5 which is a deviation between an inclination angle of the tool 5 and a target chamfering angle, and simultaneously, the path of the origin of the tool which is moved by the robot is calculated. Correction of the tool path will be described later.
In Step 8, workpieces are securely fixed on certain surfaces of the jig 7 which are predetermined for the respective workpieces, and burrs indicated on a workpiece surface of the workpiece 6 (a front view, a right side view and so on) are ground. Since the data of burr positions specified for each workpiece surface of the workpiece 6 to be ground are recorded in the CL file 12, positional data on the workpiece surfaces in the CL file 12 are transformed into positional data as viewed from the jig coordinate system in which the relative relation with the robot coordinate system is precisely exhibited. This coordinate transformation requires data which express positional relations between coordinate systems constituting the jig coordinate system which are specified by the jig numerals, coordinate systems constituting the jig surface coordinate system which are specified by the jig surface numerals, coordinate systems constituting the workpiece surface coordinate system which are specified by the workpiece surface numerals, and so forth. This will be described later.
The file produced by extracting the positional data for burr removal of the workpieces and the positional data of the tool before and after the burr removal from the CL file 12 in this manner, and by adding the target chamfering angles, the data for coordinate transformation and so forth, will now be referred to as the robot operation information file 14. In the robot operation information file 14, the CL data recorded for each workpiece surface of the workpiece 6 to be machined are stored in the order of the movement path of the tool (in the grinding order).
Since the numerals for specifying the coordinate systems of the jig to be used, the jig surface and the workpiece surface to be machined are added to the CL data recorded for each of the workpiece surfaces, the positional data in the CL data can be transformed into positional data in a reference coordinate system which serves as the origin for controlling the robot. The CL file after this coordinate transformation will now be referred to as a robot command file 17. The actual robot 1 removes burrs by real-time positional correction and control of the path positional data thus produced.
In addition to this real-time positional correction, the controller 2 for controlling the robot must fulfill many other tasks such as sensor control and communication with workpiece transfer mechanisms. Therefore, it is not favorable to apply many loads for processing instruction data to the controller 2. Consequently, when producing the robot command file 17, all the control commands which are sent to the robot 1, such as a tool change command, a movement command, and a burr-removal conducting command, are a command system which is running on the robot controller 2 actually used. It should be noted that productions of the L file 12 to the robot command file 17 are not performed in one program, but that the robot operation information file 14 and the robot command file 17 are produced by performing different programs. This is because there is considered a probability that the program size will be too large to process a large amount of data at once, and because the positional data in the coordinate systems determined for the respective workpiece surfaces, as in the robot operation information file 14, can be modified more easily than the positional data in the reference coordinate system (or the jig coordinate system) in some cases if the data must be modified. Moreover, there is a probability that additional data will be increased in accordance with diversification of kinds and materials of workpieces to be machined in the future. As a result, the program is used for various purposes, and it is necessary to respond flexibly to modification and improvement of the program. When the program is divided in this manner, it is an advantage that the program debug at the time can be performed effectively. However, if data are produced until the robot command file 17 through a single program without dividing the program, substantially the same result can be obtained except for the above-mentioned advantage that it can be used for various purposes.
Next, the algorithm which determines coefficients of cubic functions defining curves which are interpolated between the passing points in Step 5 will be explained.
To change the tool path into sequences of points is to determine positional data which express passing points where the grinding portion of the tool passes. These positional data include not only the position (Px, Py, Pz), as shown in FIG. 7, but also the direction vectors (Fx, Fy, Fz), (Gx, Gy, Gz), (Hx, Hy, Hz) indicating the posture of the tool.
When a straight section of the tool path is changed into a sequence of points, a starting point and a terminal point of the straight section are determined first. The starting point is the present position (the position where the tool has now reached) and is already known. Coordinate values immediately after GOLFT(LINE) are positional data (Px, Py, Pz) of the terminal point. In order to position the tool moved by the robot at a desired position and a desired posture, posture information denoted by F, G and H as well as the positional data are required as instruction data given to the robot. As shown in FIG. 7, the direction vector expressing the tool advancing direction (a posture F (Fx, Fy, Fz)) is a unit vector expressing a direction of a tangent line of the tool path at each passing point. That is to say, when the tool path is a straight line, it is a unit vector expressing a direction of a straight line which connects a present position P1 and a target position P2. A posture H is usually a unit vector expressing a direction of a rotational axis of the tool. In the case shown in FIG. 8, a direction Z of a coordinate system 21 in a workpiece diagram 20 is determined as the posture H (Hx. Hy. Hz). A posture G (Gx, Gy, Gz) is obtained from a vector product of H and F. The posture F determined from the present position P1 and the target position P2, the posture H and the posture Z are used to determine directions of a coordinate system used when the tool path is arcuate, as shown in FIGS. 19 and 20.
Next, there will be explained the case where an arcuate tool path is changed into a sequence of points. The total number of sequences of points defined on the arcuate tool path may be determined by a center angle of an arc, a radius of the arc, a velocity of the robot and machining accuracy. In this embodiment, however, in order to facilitate the explanation, there will be described the case where passing points on an arc are automatically defined in accordance with a center angle of the arc, as shown in FIG. 9. A sequence of points are defined on an arcuate tool path for moving the tool to a position of an expression (I) shown in FIG. 4 along an arc whose center is a coordinate value of an expression (J) in the following line of GOLFT(ARC) and whose radius is a value of an expression (K) in the subsequent line. In the arc mode, in substantially the same manner as the straight line mode, a posture F is a tangent line at each passing point, and a posture H is determined to be a Z axis direction, i.e., a direction perpendicular to the diagram surface. A tangent line at each passing point on the arcuate tool path is obtained in the following manner. As shown in FIG. 10, it is necessary to align tangent lines of points of connection between the straight lines and the arc, i.e., P1 and P2. First, when a unit vector fO expressing a direction of a tangent line, which is an advancing direction (a posture F) of the tool on the straight tool path, at a point PO is
Len0.sup.2 =(P.sub.1 x-P.sub.0 x).sup.2 +(P.sub.1 y-P.sub.0 y).sup.2
the components are
f.sub.0 x=(P.sub.1 x-P.sub.0 x)/Len0
f.sub.0 y=(P.sub.1 y-P.sub.0 y)/Len0
A unit vector f1 expressing a direction of a tangent line at a passing point P1 on the straight tool path is
f.sub.1 x=f.sub.0 x
f.sub.1 y=f.sub.0 y
Then, at the point P1, a unit vector U1 toward he center point of the arc is
u.sub.1 x=(Pcx-P.sub.1 x)/Len1
u.sub.1 y=(Pcy-P.sub.1 y)/Len1
wherein (Pcx, Pcy) expresses a coordinate of the center point of the arc, satisfying the following equation:
Len1.sup.2 =(Pcx-P.sub.1 x).sup.2 +(Pcy-P.sub.1 y).sup.2
As shown in FIG. 11, by rotating the unit vector U1 for 90° or -90° about the Z axis, unit vectors U1+ and U1-expressing directions of tangent lines of passing points on the arcuate tool path are determined. The vector U1+ which has a smaller value when comparing an angle defined by f1 and U1+ with an angle defined by f1 and U1- is determined as a unit vector expressing a direction of the posture f in a tangent direction of the tool which is moved on the arcuate tool path, at the passing point P1. This is because the posture F of the tool on the straight tool path and the posture f of the tool on the curved tool path are aligned with each other at the connecting point P1. When the direction vector expressing the tool advancing direction (the posture f) at the point P1 is determined in this manner, it is possible to determine an advancing direction of the tool on the arcuate tool path. The number of passing points on the arc is determined by the center angle of the arc, the radius of the arc, the robot operational speed and the finishing accuracy.
For instance, a center angle θ and the number of passing points are as follows:
______________________________________Center angle The number of passing points______________________________________ 0° < θ ≦ 90° 3 90° < θ ≦ 180° 6180° < θ ≦ 270° 9270° < θ ≦ 360° 12______________________________________
It should be noted that these passing points are defined by equally dividing the center angle of the arc in this case. Now supposing that the number of passing points is n, the center angle θ will be divided into sections of θ/n°. A position S1 (x, y) of a first division point (n=1) of the n passing points can be calculated from the following expression:
x=Pcx±rsin (θ/n)
(x-Pcx).sup.2 +(y-Pcy).sup.2 =r.sup.2
(wherein r denotes a radius of the arc) Expression (1)
As shown in FIG. 12, however, there are four values of (x, y) (indicated by points Δ) obtained from the expression (1) at the time of n=1. This is because the center of the circle Pc (Pcx, Pcy) is regarded as the origin in the expression (1) so that four positions (x+, y+), (x+. y-). (x-, y+) and (x-. y-) are provided. In order to obtain a position of a division point (a passing point) which the tool first passes in the advancing direction on the arcuate movement path of the tool, as shown in FIG. 12, (x, y), which forms the smallest angle α of angles α1 to α4 defined between the posture vector F at the point P1 obtained before and unit vectors expressing straight lines which connect these four positions (x+, y+), (x+, y-), (x-, y+) and (x-, y-) with the point P1, is a positional coordinate of the passing point. In order to remember a quadrant where the position selected from these four positions is located, the correspondence shown in FIG. 13 is prepared. A start (a point tangent to the straight tool path ) and an end of the arc of the tool path are denoted by Pn and Ps located at the north pole and the south pole, as shown in FIG. 13. When (x, y) which forms the smallest angle α is in the quadrant 0 of the circle, a direction counter value is 0, and when it is in the quadrant 1, a counter value is 1. In this manner, directions counter values are determined until the quadrant 3. As for the division points S2, S3 . . . after that, (θ/n)*m (m=2, 3 . . .) is substituted for sin of the expression (1), and the four values of (x, y) are calculated similarly. Depending upon a value of (θ/n)*m, selection from the four values of (x, y) is determined. For instance, when (θ/n)*m at the time of m=2 is 90° or less, the direction counter value is the same as the counter value obtained at the first passing point (m=1). However, when it exceeds 90° and is not more than 180°, the direction counter value is not the same as the counter value obtained at the first passing point (m=1).
TABLE 1______________________________________(m = 1,2,3, . . .) Increase with respect to theAmount of m*θ/n direction counter value at the(unit °) starting point of the arc______________________________________ 0 < m*θ/n ≦ 90 0 90 < m*θ/n ≦ 180 1180 < m*θ/n ≦ 270 2270 < m*θ/n ≦ 360 3______________________________________ ##STR1## Decrease with respect to theAmount of m*θ/n direction counter value at the(unit °) starting point of the arc______________________________________ 0 < m*θ/n ≦ 90 0 90 < m*θ/n ≦ 180 1180 < m*θ/n ≦ 270 2270 < m*θ/n ≦ 360 3______________________________________Direction counter value = mod (Direction counter, 4) ##STR2##Direction countervalue (X, Y) sets______________________________________0 (X+, Y+)1 (X+, Y-)2 (X-, Y-)3 (X-, Y+)______________________________________
When the direction counter value of the first passing point (m=1) is 0 or 2, the tool advances in the clockwise direction so that the counter value will be increased. However, when the direction counter value of the first passing point (m=1) is 1 or 3, the tool advances in the counterclockwise direction so that the counter value will be decreased. If the increased or decreased counter value is 0, a coordinate set of (x+, y+) is selected, and if the counter value is 1, a coordinate set of (x+, y-) is selected. In this manner, concerning the division points S2, S3 . . . , selection from the four (x, y) coordinate sets is determined in accordance with the center angle of the arc (m*θ/n) until the passing points (m=1, 2, 3 . . .).
The direction counter value is increased when the tool advances in the clockwise direction, and decreased when it advances in the counterclockwise direction. Therefore, a value of the direction counter at the arc starting point Y is determined, and a direction counter value at each of the passing points is determined in accordance with the center angle of an arc between the passing point and the arc starting point. Counting of the direction counter is effected in the robot operation determining program, and the direction counter value at each of the passing points determined in accordance with the center angle of an arc between the passing point and the arc starting point is stored in the memory.
In this calculation, it should be noted that the starting position of the arc (a tangent point of the straight movement path and the arcuate movement path) is located at the North Pole or the South Pole of the circle (the point on the Y coordinate axis). As shown in an example of FIG. 14, the starting position of the arc (the position of the point P1) is at an arbitrary location. Consequently, (x, y) coordinate values obtained in the X-Y coordinate system must be actually transformed into, for instance, coordinate values in the X'-Y' coordinate system which is a reference coordinate system of the workpiece, as shown in FIG. 14. For this purpose, an angle (θ°) for which the X'-Y' coordinate system is rotated about the Z axis with respect to the X-Y coordinate system is calculated from the following expression, and the (x, y) value in the X-Y coordinate system is rotated in accordance with this calculation result. For instance, when directional cosine vectors of coordinate axes in the X-Y-Z coordinate system are denoted by 1, m and n, and when directional cosine vectors of coordinate axes in the X'-Y'-Z' coordinate system are denoted by 1', m' and n', Δθ can be obtained from the following expression:
2cosΔθ=(1·1'+m·m'+n·n'-1)
Moreover, as shown in FIG. 15, a direction of a coordinate axis for calculating a cubic function curve which is interpolated between adjacent passing points on the arc can be obtained from a unit vector F (Fx, Fy, Fz) expressing a direction of a straight line which connects the passing point P1 with the passing point S1', and a unit vector G (Gx, Gy, Gz) which is a vector product of H and F when a unit vector H (Hx, Hy, Hz) is determined constantly to be a unit vector (0, 0, 1) perpendicular to the workpiece surface (i.e., the diagram surface).
Although a method of producing a sequence of points on an arc from the item GOLFT(ARC) has been described in the case where the tool is moved from the straight line mode to the arc mode, as shown in FIG. 10, there will now be described the case where the arc mode does not begin with a straight line. It is equivalent to the case of a ridgeline configuration which is a series of arcs, as shown in FIG. 16(A), and to the case where burrs must be removed not from the ridgeline of the workpiece but from holes in the inner surface or the outer surface of the workpiece, as shown in FIG. 16(B). In this case, a sequence of points are produced with basically the same concept. However, it is different from the former case in that the line tangent to the straight line mode can not be compared at the arc starting point P1 so that it is necessary to determine the advancing direction of the tool in a different method. For instance, the direction of the arc is counterclockwise if it is not particularly specified, and in the case shown in FIG. 16(B), the tool starts at the point P1 and is moved toward the point P2. In this case, a vector U- obtained by rotating the unit vector connecting the center of the circle with the point P1 for -90 degrees is a tangent line at the point P1, and the rest can be performed in the same algorithm as production of the arc passing points (change into a sequence of points) from the straight line mode. Further, FIG. 17 shows an example in which a straight line and an arc are continuous but their tangent lines do not align with each other at a point P1 of connection between the straight line and the arc. In this case, instead of regarding the straight line and the arc as continuous, they are divided into three sections and thought of as a straight line, an arc and a straight line.
Next, a coefficient of a cubic function defining a curve which is interpolated between adjacent passing points is determined.
In general, a cubic function is defined by y=ax 3 +bx 2 +cx+d. In the case of a straight line, however, as shown in FIG. 19, y=ax 3 +bx 2 +cx may be used for a cubic curve connecting two points (0, 0) and (1, 0) in the Tx-Ty coordinate system. In this case, in the straight line connecting the two points, the relation a=b=c=0 is established in the Tx-Ty coordinate system because y=0.
Moreover, there will be explained a method for determining a coefficient at the time of interpolation between adjacent passing points on the arcuate tool path.
As shown in FIG. 19, the cubic curve y=ax 3 +bx 2 +cx is presumed to pass the origin (0, 0) and (1, 0) in the Tx-Ty coordinate system. Also, a unit vector expressing a direction of a tangent line of the curve at the origin (0, 0) is denoted by α, and a unit vector expressing a direction of a tangent line of the curve at (1. 0) is denoted by β. By substituting x=1 and y=0 for the cubic curve y=ax 3 +bx 2 +cx, there can be obtained the following expression:
a+b+c=0
Further, when x=0 is substituted for α=3ax 3 +2bx+c.
c=α
Also, when x=1 is substituted for β=3ax 3 +2bx+c,
β=3a+2b+c
Thus,
a=α+β
b=-β-2α
c=α
Referring now to FIG. 20, there will be considered the case where a cubic curve is interpolated between a passing point P1 and a passing point P2. Unit vectors expressing directions of tangent lines at the point P1 and the point P2 are denoted by f1 and f2 in the X-Y coordinate system. The unit vectors f1 and f2 can be obtained by rotating a unit vector ##EQU1## expressing a direction of a straight line which connects O and P1 and a unit vector ##EQU2## expressing a direction of a straight line which connects 0 and P2 for +90° or -90° in substantially the same manner as +90° or -90° rotation of U1+ and U1-, as shown in FIG. 11. These two tangent direction vectors are next transformed into tangential vectors in the X12-Y12 coordinate system. In other words, when an angle defined between the X12 axis of the X12-Y12 coordinate system connecting the point P1 and the point P2, and the X axis of the X-Y coordinate system is denoted by θ, tangential vectors of f1 and f2 as viewed from the X12-Y12 coordinate system are as follows:
f1'=Rf1
f2'=Rf2
wherein ##EQU3##
In consequence, when f1'=(f1'x, f1'y) and f2'=(f2'x, f2'y),
α=f1'y/f1'x
β=f2'y/f2'x
The cubic curve coefficient can be determined from
a=α+β
b=-β-2α
c=α
Moreover, the matrix of rotation around the Z axis is expressed as follows: ##EQU4##
Correction of the tool path (Step 7) will now be described. The tool path (the path of the grinding portion of the tool) in the robot operation information file 14 shown in FIG. 3 can be regarded as a movement path along a boundary between the unnecessary portion to be removed and the rest of the workpiece 6 at the virtual center point 0 of the burr removing tool 5, as shown in FIG. 18. In order to conduct burr removal operation actually, the movement path of the reference coordinate system of the tool (The robot controls the position and the posture of this reference coordinate system.) must be calculated while conducting modification in accordance with the tool shape and the target chamfering angle. FIG. 21 illustrates tools with grinding wheels having diameters d, lengths L and angles θ which are different from one another. A Point T which is a middle position of each grinding wheel is supposed to be contacted with the workpiece. When burrs are to be removed from a portion between P1 and P2 shown in FIG. 22, the tool is first shifted for +l/2 in the Z direction and -d/4 in the X direction. Further, when the target chamfering angle is, for instance, 45°, as shown in FIG. 23, the Z axis must be inclined for δ=45°-θ/2 toward the workpiece. This is the case where the shape of the grinding wheel is conical. However, as shown in FIG. 21(B), when it is cylindrical, the tool is shifted for -d/2 in the X direction. If a certain portion of the tool 5 is used for a long time, the tool 5 will start to be worn. Since this results in deterioration of finishing accuracy in burr removal, it is necessary to displace the portion to be contacted with the workpiece, from the point T (offset displacement) so that the tool 5 will not be terribly worn. In order to define the robot path actually, the robot operational language output program receives, from the robot operation information, the tool numeral, the target chamfering angle, the tool offset amount, the location of the workpiece whether it is located on the left or right of the tool with respect to the tool moving direction, and so forth, and the tool information file 18 in which the actual shape and size of the tool for use are stored is referred to, so that correction corresponding to the tool is performed instantaneously. Thus, there is calculated the robot path for properly positioning the reference coordinate system of the tool.
Positional correction of the tool will be described more specifically.
Since the tool movement path which is recorded in the CL file produced on the basis of the CAD diagram information and the robot operation information file 14 is usually data expressing positions of edge portions (edges, ridgelines) of the workpiece, it is necessary to shift the path positional data in accordance with a diameter d and a grinding wheel angle θ of the tool for use. This method has a prerequisite that a posture h of the tool is in substantially the same direction as the Z axis and an advancing direction f of the tool is in substantially the same direction as the X axis, as shown in FIG. 24. When the grinding portion of the tool is located on the right with respect to the tool advancing direction f, as shown in FIG. 24, and the tool is rotated for δ in the clockwise direction around the f axis, the following expressions are established:
g'=cos δg+(1-cos δ)(f·g)f
h'=cos δh+(1-cos δ)(f·h)f.
Next, when the diameter at that portion of the tool where the tool and the workpiece are actually contacted is denoted by d' (as described above), the tool position is ##EQU5## wherein p expresses a correction amount, and sig expresses a constant which is 1 when the grinding portion is located on the right with respect to the tool advancing direction and which is -1 when it is located on the left.
When the above-mentioned offset amount is added to this, ##EQU6## wherein of denotes the offset amount.
Next, coordinate transformation (Step 8) will be explained.
So far, there has been described the method of using the CAD diagram and defining the operation path of the reference coordinate system of the tool from the data in the CL file 12 by the robot 1. The CL data include definitions of the coordinate systems for the respective surfaces of the workpiece diagram, as described above, and the positional data are values in the respective coordinate systems. In order to control the robot 1, it is necessary to transform the positional data in the respective coordinate systems into coordinate values as viewed from a common reference coordinate system. When machining the workpieces 6, each of the workpieces is always attached to the predetermined jig 7. Therefore, as the common reference coordinate system, a coordinate system of each jig (the jig coordinate system) is employed. The positional data produced in the robot operation determining file 14 shown in FIG. 3 are transformed into positional data in the jig coordinate system. After that, the positional data in the jig coordinate system are transformed into positional data in a robot coordinate system and stored in the robot command file 17. The coordinate transformation from the workpiece surface coordinate system to the robot coordinate system is performed in the following flow:
Workpiece surface coordinate systemWorkpiece coordinate systemJig surface coordinate system Jig coordinate systemRobot coordinate system
FIG. 25 illustrates one example of a condition in which workpieces are securely fixed on a jig.
Each workpiece is attached on a `surface` of the jig, and burrs on a `surface` of the workpiece are ground. Therefore, the jig surface coordinate system corresponding to the jig coordinate system is required, and the workpiece coordinate system as viewed from each jig surface is required to know a region on the jig surface where the workpiece is located. In the tool path defining program, the jig numeral, the jig surface numeral and the workpiece surface numeral for specifying the coordinate system to be used among the coordinate systems constituting the jig and workpiece coordinate systems are added to the CL data produced for each workpiece surface, and the above-described coordinate transformation is effected on the basis of these numerals. Jig surfaces and workpiece surfaces are denoted by jig surface numerals and workpiece surface numerals, for example, as shown in FIG. 26. Further, in FIG. 27, four identical workpieces are attached on a certain jig surface. Even if the attaching directions are rotated for 180° in this example, CL data for one workpiece are produced by checking the number of workpieces on the jig surface (four in this case) and defining four workpiece coordinate systems in the CL file 10 when these four identical workpieces all have the same grinding portion and the same grinding order.
Hereinafter, correction of a tool path on the basis of a measured actual workpiece configuration will be described with reference to FIGS. 28 to 35.
A search command and an operation command used for correction of the tool path on the basis of the actual workpiece configuration will now be described. The search command includes a designated search point which is a coordinate value for specifying the position of a point on the workpiece whose actual shape will be measured, and a designated search direction expressing an advancing direction of a shape measuring sensor for measuring the actual shape at the designated search point. The search command is designed to be incorporated in a robot control sequence when it makes a pair with the operation command for specifying a search point where the actual shape is measured, this actual shape being used for a correcting method and the correction of the movement path of the tool on the basis of the measured actual shape in a burr removal operation sequence of the robot. For each of operational portions (burr removal positions) specified by a command for the robot control, a search point and a search direction are specified to obtain the real position of the operational portion. On the other hand, a correcting method and a search point to be used are specified in the operation command so that a drive command value is corrected on the basis of the real positions (the shape) of the designated search points actually searched. More specifically, the following correcting methods of various kinds are specified.
Correcting method 1: Only one search point is used, and the movement path of the tool is shifted to an extent corresponding to a deviation between the position of the workpiece which is actually measured at the search point and a designed value of the position of the workpiece at the search point.
Correcting method 2: A line segment connecting positions of the workpiece which are actually measured at two search points and a line segment connecting designed values of positions of the workpiece at the search points are obtained, and the movement path of the tool on the basis of a designed value of a passing point is shifted to an extent corresponding to a deviation between a projection point of the designed value of the passing point on the line segment to be corrected (the movement path of the tool) with respect to the line segment between the designed values, and a projection point of the designed value of the passing point with respect to the line segment between the search points.
Correcting method 3: A plane with search points including positions of the workpiece which are actually measured at the three search points and a plane with designed values including the designed values of positions of the workpiece at the search points are obtained, and the movement path of the tool on the basis of a designed value of a passing point is shifted to an extent corresponding to a deviation between a projection point of the designed value of the passing point on the plane to be corrected (the movement path of the tool) with respect to the plane with the designed values, and a protection point of the designed value of the passing point with respect to the plane with the search points.
Correcting method 4: According to the correcting methods 1 to 3, when coordinate components to be corrected are restricted, only the restricted coordinate components are corrected.
Consequently, after suitably specifying points to be searched and correcting methods for each of the operational portions, the search command including these points and the operation command which specifies the correcting methods and search points to be used are incorporated into the operation sequence of the robot, so that not only an operation with respect to each of the operational portions of an operation object but also an operation with respect to a different object of the same kind can be performed by the robot quite favorably.
For concrete explanation of the present invention, a robot system to which the invention is applied (a burr removing robot system in this embodiment) will be described first. FIG. 1 illustrates a system structure of the one embodiment. With this structure, in a host processor 3, designed size data values are preliminarily produced in relation to operation objects of various kinds and stored as a data file, from which designed size data values of each of desired operational portions are extracted. A robot operational course, a command for burr removal and a search command (including designated search points, designated search directions and designated correcting methods) are produced on the basis of these designed size data values. The command for burr removal is interpreted by an interpreter in a robot drive/control means 2, and then, a robot 1 is controlled to operate in a predetermined manner by the robot operational course, the command for burr removal and the search command. A burr removing tool 5 and a power sensor (not shown) are attached on a hand of the robot 1. Burrs existing on a ridgeline of each operational portion of an operation object (not shown) which is substantially positioned are ground and removed by the burr removing tool 5. In order to define a robot operational course in the host processor 3, when the ridgeline from which burrs are to be removed is a curve, the ridgeline is smoothly approximated to a cubic expression, and a coefficient of the cubic curve as well as a drive command position and a posture condition is registered as the burr-removal command. Also, the search command is registered in the robot operation sequence when it makes a pair with the burr-removal command. The designated search directions contained in the search command are, concretely, directions perpendicular to the plane on which the search points exist.
For removing burrs from the ridgeline which is an object for burr removal, search operations are first conducted successively for the respective designated search points (the number of the search points is one or more and three or less per correcting method) by executing the search command, and then, burr-removal operation with respect to the ridgeline is performed. The search command and the burr-removal command with respect to the ridgeline are supplied from the work station 3 to the robot drive/control means 2, for example, in the following format (the number of designated search points is two in this embodiment):
SEARCH
Search numeral 1
Designed value of designated search point x 1
Designated search direction d 1
SEARCH ps Search numeral 2
Designed value of designated search point x 2
Designated search direction d 2
CUT
Designated correcting method 2
Employed search numeral 1, 2
Sequence of command passing points x 2 , x 2 , . . . , x n
`SEARCH` expresses a search command, and `CUT` expresses a burr-removal command. `2` of the designated correcting method is a correcting expression numeral which specifies a type of combination of one of the above-described correcting methods 1 to 3 with the correcting method 4. In this embodiment, the `correcting method 2` is specified as the correcting expression numeral. The real position of the ridgeline which is the burr-removal object is calculated by executing the search command twice, and the sequence of command passing points x 1 , x 2 , . . . , x n is corrected on the basis of the real position thus calculated. Correction at the time is performed by the specified correcting method. The number of search commands, i.e., the number of designated search points is one when a designated search object is a point, two when it is a straight line, and three when it is a plane. It should be noted that underlined variables denote vectors, and that such denotement is employed in the same manner in expressions and drawings of various kinds illustrated below.
One portion of an internal structure of the robot drive/control means 2 in the robot system shown in FIG. 1 will now be described with reference to FIG. 29. As shown in the illustration, a CAD means 101 and a host processor 102 in the work station 3 are connected to the robot drive/control means 2 through a network bus 107 so that data of various kinds can be transferred between these means 101, 102 and 2, if necessary. In the internal structure of the robot drive/control means 2, as shown in the illustration, a central processing unit 103-1, a memory (an RAM for workpieces and an ROM for storing programs) 103-2, an interface unit for communication 103-3, a digital/analog converter (corresponding to an actuator) 103-4, a counter board (for counting signals from a plurality of encoders 104-2) 103-5, an analog/digital converter (for digital conversion of signals from a power sensor 104-1) 103-6, and a parallel I/O board (for data input/output with an input/output means in the vicinity) 103-7 are connected to one another through an inner bus 103-8. When the actuator 104-1 is driven through a servo amplifier 103-9 by analog output from the digital/analog converter 103-4, the robot 1 is operated in a desired manner, and its position/posture conditions can be known from count values at the counter board 103-5. An amplifier 103-10 serves to amplify a sensor signal from the power sensor attached in the vicinity of a hand of the robot 1 so that when a search command is executed, it will be detected from the sensor signal that the hand of the robot 1 is contacted with a designated search point on the operation object.
Execution of a search command according to this invention will be described with reference to FIG. 28 showing a flow of the executing operation. The search command is designed to be executed not less than once and not more than three times in each of the correcting methods. As shown in the illustration, for executing a search command corresponding to a search numeral N, the robot drive/control means 2 first functions in such a manner that the robot 1 is driven in a designated search direction d N specified by the search command until the hand of the robot 1 is contacted with an operation object. It is judged by a sensor signal from the power sensor 104-3 whether or not the hand is contacted then. When a signal level of the sensor signal reaches a certain value, contact with the designated search point on the operation object is detected. Therefore, from each of a plurality of count values θ N from the counter board 103-5 at the time of contact, a real position x N of the designated search point can be calculated as Tθ N (T: a coordinate transformation matrix) by coordinate transformation. The real position x N is temporarily stored in the memory 103-2 corresponding to each of the search numerals N. Since the real position x N is obtained corresponding to each of the search numerals N in this manner, it is possible to calculate the real position of the ridgeline which is the burr-removal object. On the basis of this result, the sequence of command passing points x 1 , x 2 , . . . , x n are transformed into a sequence of command passing points y 1 , y 2 , . . . , y n in accordance with the real position of the ridgeline by a correcting method corresponding to the specified correcting expression numeral.
FIG. 30 shows a flow of transformation processing from the sequence of command passing points x 1 , x 2 , . . . , x n into the sequence of command passing points y 1 , y 2 , . . ., y n . As described before, each of the ridgelines which are burr-removal objects is denoted by a correcting expression numeral i, and correcting transformation processing corresponding to the correcting expression numeral i is carried out. In this embodiment, however, for facilitating the explanation, there are presumed the case where no correcting transformation processing is conducted (the correcting expression numeral=-1), and the case where correcting expression numerals 1 to 3 are assigned to the above-described correcting methods 1 to 3, respectively. As shown in the illustration, when the correcting expression numeral is `-1`, the sequence of designed command passing points x 1 , x 2 , . . . , x n are used, as they are, as the sequence of command passing points y 1 , y 2 , . . . , y n corresponding to the real position of the ridgeline. Further, when the correcting expression numeral is one of 1 to 3, the associated correcting transformation processing is carried out. For instance, when a search object is a plane, the search command is executed three times to obtain real positions s 1 , s 2 and s 3 , at three designated search points. By a correcting transformation matrix F 3 on the basis of these real positions and designed values of the designated search points r 1 , r 2 and r 3 , the sequence of command passing points x 1 , x 2 , . . . , x n are transformed into the sequence of command passing points y 1 , y 2 . . . y n . While movement control of the robot 1 is conducted on the basis of this sequence of command passing points y 1 , y 2 , . . . , y n , burr-removal operation is performed with respect to the ridgeline.
Basically, three kinds of correcting methods are prepared, as described above, and a suitable correcting method is designated for each of the operational portions in the form of a correcting expression numeral. These methods will be described more specifically below.
First, there will be explained the case where the correcting expression numeral is `1`. For instance, as shown in FIG. 31 illustrating a workpiece 108, when grinding a ridgeline (indicated by a heavy line) where two surfaces 108-1 and 108-2 machined by an NC machining tool intersect with each other, values from the host processor 3 can be used, as they are, as coordinate values in the X and Z directions. However, when the positional accuracy in the Y direction is not ensured, there is employed a correcting method in which only one search point is used, and only Y direction components of the sequence of command passing points x 1 , x 2 , . . . , x n are shifted to a degree corresponding to a deviation between a real position and a designed value of the workpiece 108 at the point. In this embodiment, with one point on the surface 108-3 serving as a designated search point, search of the designated search point is conducted in a direction of the vector d 1 , i.e., in the +Y direction. As a result, when a measured value at the searched designated search point is denoted by q, and a designed value supplied from the CAD data is denoted by p, a point y can be obtained from a designed value x of a point on the ridgeline through the following correction:
y=x+N*(q-p)
N in the expression expresses a matrix for selecting coordinate components of a correction object and is composed of the following elements such that coordinate components in the search direction will be selected. However, it is possible to conduct multiplication intentionally by a matrix for selecting particular coordinate components. ##EQU7##
Next, there will be explained the case where the correcting expression numeral is `2`. As shown in FIG. 32 illustrating a can product 109, when a surface 109-1 is machined by the NC machining tool and a ridgeline (indicated by a heavy line) on the surface 109-1 is ground, a value from the host processor can be used, as it is, as a coordinate component perpendicular to the surface to be ground, i.e., the X component. However, since it is a welded article, accuracy of the other coordinate components is not ensured so that correction will be necessary. In such a case, correction by only one-point search is performed for the Y component. For the Z component, two-point search is performed in directions of vectors d 1 and d 2 shown in FIG. 32, and then, correction is conducted in the following manner.
That is to say, when designed values of two designated search points are denoted by r 1 and r 2 , measured values at the respective designated search points are denoted by s 1 and s 2 , a direction vector of a line segment connecting the designed values r 1 and r 2 is denoted by l, and a direction vector of a line segment connecting the measured values s 1 and s 2 is denoted by l s , these direction vectors l and l s , are expressed as follows: ##EQU8##
FIG. 33 is a diagram in which the direction vectors l and l s , and a direction vector l e in parallel to the ridgeline to be ground are displaced in parallel onto a plane including two search direction vectors. When a perpendicular line from a designed point x on the ridgeline reaches a line segment l at a point p, and a line segment xp and a line segment l s intersect at a point q, the following relations are established:
p=((x-r.sub.1)·l)l+r.sub.1
(q-p)·l=0
q=αl.sub.s +s.sub.1
From these relations, α is expressed as follows: ##EQU9##
By the way, the points p and q are those points on the line segment connecting the designed values r 1 and r 2 and the line segment connecting the measured values s 1 and s 2 , respectively, which correspond to the point x to be corrected. Consequently, after obtaining a deviation between these points p and q, the point x to be corrected is shifted to a point y by the above-described expression y=x+N*(q-p).
Moreover, there will be explained the case where the correcting expression numeral is `3`. As shown in FIG. 34 illustrating a can product 110, when a surface 110-1 is machined by the NC machining tool and a real inclination value of a surface 110-2 on which a ridgeline (indicated by a heavy line) exists is different from a designed value, it is necessary to obtain the real inclination value of the surface 110-2. For this purpose, after specifying three designated search points on a surface 110-2 on the basis of designed values, these designated search points are searched from a normal direction on the surface 110-2 to directions of vectors d 1 , d 2 and d 3 , i.e., in the -Z direction, so that the points on the ridgeline will be corrected in the following manner.
More specifically, as shown in FIG. 35, when measured values of the three searched designated search points are respectively denoted by S 1 , S 2 and S 3 , designed values of the three designated search points are respectively denoted by r 1 , r 2 and r 3 , a plane defined by the measured values S 1 , S 2 and S 3 is denoted by f s , a plane defined by the designed values r 1 , r 2 and r 3 is denoted by f r , a normal vector on the plane f s is denoted by h s , and a normal vector on the plane f r is denoted by h r , h s and h r can be obtained in the following manner: ##EQU10##
When a perpendicular line drawn from a point x on the ridgeline toward the plane f r intersects the plane f r at a point p, the following relational expressions are established:
(p-r.sub.1)·h.sub.r =0
(p-x)×h.sub.r =0
Consequently, the point x can be obtained from these expressions in the following manner:
p=x-(h.sub.r ·x)h.sub.r +(r.sub.1 ·h.sub.r)h.sub.r
Also, when a straight line drawn from the point x through the point p toward the plane f o intersects the plane f, at a point q, the following relational expressions are established:
(q-p)×h.sub.r =0
(q-s.sub.1)·h.sub.s =0
Therefore, the point q can be obtained from these expressions in the following manner: ##EQU11##
Thus, after obtaining a deviation between these points p and q, the point x on the ridgeline which is a correction object is shifted to a point y by the above-described expression y=x+N*(q-p).
A method of calculating a movement path of a tool and its posture which are required for controlling robot operation on the basis of a designed shape of a workpiece while performing correction corresponding to a designed shape of at least one surface of the workpiece which extends from an unnecessary portion of the workpiece to be removed will now be described with reference to FIGS. 36 to 38.
Since a portion of the workpiece from which burrs are to be removed is located along a ridgeline which is a boundary (a connecting line) between two surfaces of the workpiece (a shape of the path is an arbitrary curve), a grinding portion of a burr removing tool must be moved along the ridgeline while it is pressed against the ridgeline, and perform chamfering grinding at a certain angle with respect to at least one surface of the workpiece which extends from the burrs. For this purpose, path instruction data supplied to the robot are produced in the following method.
That is to say, that ridgeline (the boundary between the unnecessary portion to be removed and the rest of the workpiece) on the designed shape of the workpiece from which burrs are to be removed is divided into segments. One of the two workpiece surfaces extending from the ridgeline is selected for specifying a chamfering angle, and a point is virtually determined, for each of the segments, on the selected workpiece surface on the designed shape of the workpiece in the vicinity of the segment, so that a triangle will be defined by both end positions of the segment and this point. More specifically, as shown in FIG. 36, points A and B are determined for segments O 1 -O 2 and O 2 -O 3 , respectively, thereby defining triangles ΔO 1 AO 2 and ΔO 2 BO 3 . A normal line on each of these triangles ΔO 1 AO 2 and ΔO 2 BO 3 is regarded as a normal line on the workpiece surface on the designed shape of the workpiece in the vicinity of each of the segments. After that, in each of the segments, a unit vector f v expressing a direction of a straight line which connects both ends of the segment (the suffix v is a vector indication, and such indications will be similarly used below), a unit vector h v expressing a direction of a normal line on the workpiece surface in the vicinity of the segment, and a unit vector g v expressing a direction perpendicular to these unit vectors f v , h v are determined. Thus, rectangular coordinate systems O 1 -f 1v g 1v h 1v , O 2 -f 2v g 2v h 2v are respectively determined corresponding to the segments O 1 -O 2 and O 2 -O 3 . The f v direction corresponds to the x axis, the g v direction corresponds to the y axis, and the h v direction corresponds to the z axis. The shape of each of the segments is approximated by an algebraic curve. This will be described in relation to the rectangular coordinate system O 1 -f 1v g 1v h 1v . Directions of tangential lines at the points O 1 and O 2 are denoted, respectively, by t 1v and t 2v , and algebraic curves having the tangential lines at the points O 1 and O 2 are determined as follows:
y=a.sub.y x.sup.3 +b.sub.y x.sup.2 +C.sub.y x
z=a.sub.z x.sup.3 +b.sub.z X.sup.2 +C.sub.z x
wherein a unit of the length is a length of the segment O 1 -O 2 . In this case, the following relation is established between coefficients of the algebraic curves:
a.sub.y1 =b.sub.y1 +C.sub.y1 =0
c.sub.y1 =t.sub.1 ·g.sub.1 /t.sub.1 ·f.sub.1
3a.sub.y1 +2b.sub.y1 +c.sub.y1 =t.sub.2 ·g.sub.1 /t.sub.2 ·f.sub.1
Concerning other coefficients a z , b z , c z , substantially the same relation is established. Therefore, by solving these relational expressions, a cubic function defining a curve interpolated between both ends of the segment is univocally determined. When the above-described processing is performed for each of the other segments, a coefficient of a cubic algebraic equation expressing an approximate curve of the ridgeline is determined for the segment. By the way, when a cubic curve is set for each of the segments, as described above, the cubic curve passes the end portion of the segment, so that if tangential lines at end portions of curves which approximate shapes of two adjacent segments have the same direction, the curves which approximate the shapes of the two segments will be continuous with each other at the end portions. In a specifying method of path instruction data for the robot, when burr removal is performed along a curve connecting points O 1 , O 2 and O 3 , for example, the path instruction data will be specified in the robot drive/control means 2 in a data form shown in FIG. 37. In this data form, O denotes a position of a starting point of a segment, a y , b y , c y , a z , b z , c z denote coefficients of cubic functions defining curves which are interpolated between both ends of the segment, and d x , d y , d z denote components of a unit vector expressing a normal direction of the workpiece surface in the vicinity of the segment.
When the path instruction data in such a data form are specified in the robot drive/control means 2, a control command value for the robot 1 is calculated in the robot drive/control means 2 so as to drive and control the tool along the interpolation curve. That is to say, for each of the segments defined in the input means 3, the positions of points where the tool is to pass (passing points) at each sampling time (at predetermined intervals) are determined. In accordance with a designated tool movement speed, distances between the passing points are changed. If the passing point thus determined is on the rectangular coordinate system O 1 -f 1v g 1v h 1v and its X axis coordinate value is p f , and when a direction of a tangential line of an algebraic curve at the position of the passing point is a vector f fv , it has a component of (1, 3a y1 p f 2 +2b y1 p f 1 +c y1 , 3a z1 p f 2 +2b z1 p f 1 +c z1 ) on the rectangular coordinate system O 1 -f 1v g 1v h 1v . Consequently, after it is set as a unit vector, it is transformed into a unit vector in a reference coordinate system (e.g., the workpiece coordinate system or the jig coordinate system or the robot coordinate system). Although a reference direction for a chamfering angle is h 1v , the ridgeline may be a curve in a three-dimensional space. Therefore, since f fv and h 1v are not necessarily at a right angle, the following vector h rv is introduced as a new reference direction:
h.sub.r =f.sub.f ×g.sub.1 /|f.sub.f ×g.sub.1 .vertline.
When the segment is short enough, a difference between f 1v and f fv is not large, so that the above expression is established. As shown in FIG. 38, a rotational axis direction of the burr removing tool 5 is such that the reference direction h rv is rotated about the f fv axis in accordance with a predetermined chamfering angle. The axial direction of the burr removing tool 5 thus obtained is denoted by h fv , and a vector g fv (=h fv ×f fv ) in a direction toward the workpiece is determined, so that (f fv , g fv , h fv ) will be a target value of the posture of the burr removing tool 5. A target value of the position P fv is (p x , a y1 p x +b y1 p x +c y1 p x , a z1 p x +b z1 p x +c z1 p x ) on the rectangular coordinate system O 1 -f 1v g 1v h 1v . At the time of burr removal, a predetermined speed is specified in the f fv direction. On the other hand, in the g fv direction, power applied to the burr removing tool 5 is detected by the power sensor 6, so that pressing control with a certain force or compliance control will be performed on the basis of this detection result.
Finally, the calculation procedure at the time of actual drive control in the robot drive/control means 2 will be described. First, a target position of a passing point is determined through linear interpolation operation as a point which the tool is to reach from the point O 1 at each sampling time in accordance with a distance from the point O 1 (a coordinate value on the X coordinate axis) which is specified on the segment O 1 -O 2 on the basis of a designated speed command value. When this point is denoted by P, a tangential direction of a point on an algebraic curve corresponding to the point P can be calculated from (1, 3a y1 p f 2 +2b y1 p f 1 +c y1 , 3a z1 p f 2 +2b z1 p f 1 +c z1 ) described above. After that, a vector h rv expressing a reference direction for a chamfering angle is determined from the above-mentioned expression. Then, the vector h rv expressing the tool posture reference direction is rotated for a specified chamfering angle around the tangential vector f fv . Therefore, the drive control of the robot is carried out while using the coordinate P v , (f fv , g fv , h fv ) as position and posture target data of the burr removing tool 5. At that time, a control command value in the g fv direction is determined on the basis of the detection result of the power sensor 6 so as to press the burr removing tool 5 with a certain force. Such drive control is not limited to the burr-removal operation, but can be applied similarly to finishing operation with respect to the ridgeline.
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A robot for removing an unnecessary portion on a workpiece, comprises a tool for removing the unnecessary portion, a tool positioning apparatus which contains a reference coordinate system, carries the tool attached thereon, and is movable to change a position and a posture of the tool in the reference coordinate system, a jig on which the workpiece is securely fixed to maintain a desired position and a desired posture of the workpiece with respect to the reference coordinate system of the tool positioning apparatus, and an arithmetic unit for calculating a movement path and a posture of the tool moved by the tool positioning apparatus on the basis of a position of the unnecessary portion on a desired shape of the workpiece, in which the arithmetic unit corrects the movement path and the posture of the tool not in accordance with the position of the unnecessary portion on the desired shape of the workpiece, but in accordance with a shape of at least one of the workpiece, the tool and the jig.
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BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for decontaminating soil and waste materials, particularly to a method and apparatus for removing volatile and semivolatile hazardous organic contaminants from soil, municipal, chemical and refinery sludges and other particulate materials.
DISCUSSION OF THE PRIOR ART
With increased environmental awareness and discovery of many landfills, dumps sites and the like containing contaminated soils and waste materials, a number of soil decontamination methods and apparatus have been proposed. These include systems disclosed in U.S. Pat. Nos. 4,738,206, 4,782,625 and 4,864,942. It is vitally important that many of these contaminated areas be freed from hazardous contaminants because of their potential toxicity. Many sites are so close to areas inhabited by humans that direct contact with the soil or waste materials or ingestion of fugitive vapors can be lethal. Also, many sites have the potential to leach hazardous contaminants into ground water supplies, thereby posing further danger. It has accordingly become necessary to develop methods which effectively remove all of the contaminants in a cost efficient manner and dispose of them in an environmentally safe manner.
U.S. Pat. No. 4,738,206, issued to one of the inventors hereof and owned by the assignee hereof, discloses an apparatus and method for removing volatile organic contaminants containing moisture by sealing the soil in a stripping conveyor against contact with air and countercurrently vapor stripping the contaminants at a temperature below the boiling points of the contaminants. This method and apparatus has proven to be quite effective for decontaminating soils in many situations.
U.S. Pat. No. 4,782,625 discloses a mobile decontamination apparatus for removing halogenated hydrocarbons, petroleum hydrocarbon and derivatives of petroleum hydrocarbons from soil. However, this apparatus suffers the severe problem of being open to the environment. Open systems can be quite hazardous and frequently cause difficulties in obtaining proper permitting for operation thereof.
U.S. Pat. No. 4,864,942 discloses a process and apparatus for thermally separating organic contaminants such as PCB's from soils and sludges. This apparatus provides inadequate disposition of vaporized organic contaminants after volatilization from the soils and sludges.
Other prior art known to applicant in completely different areas of endeavor include U.S. Pat. Nos. 2,753,159; 2,731,241; 3,751,267; 4,098,200; 4,139,462; 4,167,909; 4,319,410; 4,330,946; 4,411,074; 4,504,222; 4,544,374; 4,628,828; 4,875,420 and 4,881,473.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a method and apparatus for removing volatile and semivolatile hazardous organic contaminants from soil and sediments.
It is a further object of the invention to provide a method and apparatus for removing volatile and semivolatile hazardous organic contaminants from waste materials such as municipal, refinery and chemical sludges and other particulate wastes.
It is another object of the invention to provide a method and apparatus capable of decontaminating large quantities of natural soil without transporting the soil to remote locations.
It is yet another object of the invention to decontaminate soil in a manner which poses no environmental risk to surrounding areas and is free from danger of explosion of fire.
Other objects and advantages of the invention will become apparent to those skilled in the art from the drawings, the detailed description of preferred embodiments and the appended claims.
SUMMARY OF THE INVENTION
This invention provides a method for removing volatile organic contaminants from soil and waste materials including removing contaminated material to be treated from its existing location, transporting and placing the contaminated material into a hopper wherein the hopper is substantially sealed from the atmosphere to prevent fugitive emissions of the contaminants from escaping into the atmosphere. The contaminated material is then conveyed under sealed conditions into a heated vapor stripping conveyor. The contaminated material is conveyed under sealed conditions along the vapor stripping conveyor to heat the contaminated material and thereby cause moisture in the material and the contaminants to be stripped away.
At the same time the contaminated material is conveyed along the vapor stripping conveyor, non-oxidizing gases are swept across the surface of the material to carry volatilized contaminants and moisture emanating from the material across and away from the material. The cross-sweep of non-oxidizing gas is maintained at a rate of flow and temperature to prevent undue surface drying of the material as the material passes through the conveyor.
The invention further provides an apparatus for removing organic contaminants from the contaminated material including a hopper, means for sealing the material from atmospheric air, a heated vapor stripping conveyor sealed from the atmospheric air to vapor strip the volatile contaminants from the material and means for conveying the material in a sealed condition from the hopper to the vapor stripping conveyor.
The apparatus further includes means for supplying non-oxidative gases at a temperature greater than ambient to the vapor stripping conveyor, means for introducing the non-oxidative gases into the vapor stripping conveyor and means for removing the non-oxidative gases from the conveyor located to cause the non-oxidative gases to cross-currently sweep over the material to convey volatile contaminants stripped from the material out of the vapor stripping conveyor. The apparatus still further includes means for controlling the flow rate and temperature of the non-oxidative gases as they flow through the vapor stripping conveyor and across the material to prevent undue surface drying of the material as it passes through the vapor stripping conveyor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a schematic diagram showing one preferred form according to which the invention may be practiced.
FIG. 2 shows a schematic top plan view of a vapor stripping material conveyor utilized in accordance with aspects of the invention.
FIG. 3 represents a schematic diagram showing another preferred form according to which the invention may be practiced.
FIG. 4 is a schematic diagram showing preferred vapor treatment apparatus utilized in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Although a particular form of apparatus and method has been selected for illustration in the drawings, and although specific terms will be used in the specification, for the sake of clarity in describing the apparatus and method steps shown, the scope of this invention is defined in the appended claims and is not intended to be limited either by the drawings selected or the terms used in the specification or abstract. When referring to contaminated soil or waste materials such as municipal, refinery or chemical sludges or particulates, waterway and lagoon sediments and the like the terms "contaminated materials" or "materials" will be used hereinafter for the sake of convenience.
Referring now to the drawings in general and FIG. 1 in particular, one embodiment of a decontamination system 10 is shown. Material removing conveyor 12, which may be a conventional belt conveyor, belt conveyor with scoops, front and loader, backhoe or the like, removes contaminated material 14 from its existing location and places it in container 16. Container 16 connects to feeder 18, which connects to sealed conveyor 20. Contaminated material 14 travels under sealed condition to the front end 22 of vapor stripping conveyor 24 by way of hopper 23. Vapor stripping conveyor 24 contains a stripping conveyor 26 (see FIG. 2). The stripping conveyor 26 connects to heat transfer fluid supply line 28 and fluid return line. Fluid supply line 28 and fluid return line 30 connect to fluid heater 32.
Vapor stripping conveyor 24 is shown with four non-oxidative gas feed lines 33, 34, 36, 38 connected to one side thereof. The feed lines are positioned substantially equally spaced apart along the longitudinal axis of vapor stripping conveyor 24 and are similarly positioned about mid-way along the vertical direction of vapor stripping conveyor 24. Non-oxidative gas feed lines 33, 34, 36, 38 connect to a non-oxidative gas supply line 40, with one branch 40a connecting to heater 32 and another branch 40b connecting to non-oxidative gas supply fan or blower 42. Non-oxidative gas supply blower 42 connects to non-oxidative gas source 44. Valve 43 may be opened or closed to control the rate of non-oxidative gas channelled to blower 42.
The side of vapor stripping conveyor 24 opposite non-oxidative gas feed lines 33, 34, 36, 38 has four vapor exhaust lines 46, 48, 50, 52 (see FIG. 2) which connect to vapor exhaust manifold 54. Supplemental vapor exhaust conduit 56 extends between sealed conveyor 20 and vapor exhaust manifold 54. Vapor exhaust manifold 54 also connects to vapor exhaust blower 58, which connects to vapor exhaust cleaner apparatus 60. Vapor exhaust cleaner apparatus 60 has exhaust purge conduit 62 and exhaust purge recycle conduit 64 connected downstream. Exhaust purge recycle conduit 64 connects to non-oxidative gas supply 44. Heater 32 has air intake line 66 to supply combustion air and exhaust line 68 to exhaust combustion gases to the air or to vapor stripping conveyor 24. Decontaminated material exits the bottom of vapor stripping conveyor 24 at chute 70.
FIG. 2 shows one preferred embodiment of a vapor stripping conveyor 24 which may be used to practice the invention. Vapor stripping conveyor 24 has non-oxidative gas feed lines 33, 34, 36, 38 connected on one side and vapor exhaust lines 46, 48, 50, 52 connected on the other side. The non-oxidative gas feed lines and vapor exhaust lines are shown entering and exiting vapor stripping conveyor 24 at essentially right angles to the direction of travel of the material. Non-oxidative gas feed lines 33, 34, 36, 38 connect to non-oxidative gas supply line 40 (FIG. 1) and vapor exhaust lines 46, 48, 50, 52 connect to vapor exhaust conduit 54, also shown in FIG. 1.
The interior of vapor stripping conveyor 24 shows two stripping conveyors 26, which include hollow shafts 72 and hollow rods 72 and flights 74. These conveyors are rotated by a motor and gear reducer 73 (shown schematically). The dashed lines on front end 22 of vapor stripping conveyor 24 represent the entry point of sealed hopper 23 from above, while the dashed lines on the other end of vapor stripping conveyor 24 represent the exit point for the contaminated material flowing through chute 70.
FIG. 3 shows a schematic view of another preferred embodiment of the invention. The upper portion labelled "A" of the apparatus is similar to that shown in FIG. 1 of the drawings and contains substantially the same numbers applied to the various component portions thereof. In particular, contaminated material 14 travels along conveyor 12 and into container 16. Container 16 connects to feeder 18, which sealingly connects to sealed conveyor 20. The other end of sealed conveyor 20 connects to hopper 23 which sealingly connects to vapor stripping conveyor 24. Vapor stripping conveyor 24 further connects to heat transfer fluid supply line 28, non-oxidative gas feed lines 33, 34, 36, 38 and vapor exhaust lines 46, 48, 50, 52.
Also, supplemental vapor exhaust conduit 56 extends between sealed conveyor 20 and vapor exhaust manifold 54. Vapor exhaust manifold 54 extends between vapor exhaust blower 58 and vapor exhaust lines 46, 48, 50, 52. Similarly, vapor exhaust cleaner apparatus 60 connects between vapor exhaust blower 58 and exhaust purge recycle conduit 64. Exhaust purge recycle conduit 64 also connects to non-oxidative gas supply line 40.
The portion of FIG. 3 labelled "B" is similar to the apparatus shown in portion "A". A vapor stripping conveyor 124 is shown connected to vapor stripping conveyor 24 through a transfer chute 76. One end of transfer chute 76 connects to the bottom of vapor stripping conveyor 24 and to the top of vapor stripping conveyor 124. Vapor stripping conveyor 124 is shown having four non-oxidative gas feed lines 133, 134, 136, 138 and four vapor exhaust lines 146, 148, 150, 152. Vapor exhaust lines 146, 148, 150, 152 connect to vapor exhaust manifold 154, which in turn connects to vapor exhaust manifold 54. Chute 170 connects to the bottom of vapor stripping conveyor 124 at the end opposing transfer chute 176.
Vapor stripping conveyor 124 further connects to a heat transfer fluid supply line 128, which connects to heater 32 and fluid return line 30, which also connects to heater 32. Non-oxidative gas feed lines 133, 134, 136, 138 all connect to non-oxidative gas supply line 140, which connects to branches 40a and 40b. Non-oxidative gas supply blower 42 extends between branch 40b and non-oxidative gas source 44.
FIG. 4 is an exploded representation of one preferred form of exhaust cleaner apparatus 60. The number 61 represents a burner for burning organics received from stripping conveyor 24 and vapor exhaust blower 58. Condenser and carbon absorber 67 connects to blower 58 and condenses some of the hazardous constituents. Catalytic thermal destructor 65 connects to blower 58 and receives exhaust gases from stripping conveyor 24. Wet scrubber 63 connects to burner 61 and catalytic thermal destructor 65 to further treat the exhausted gases.
Referring now to FIGS. 1 and 2 of the drawings, one preferred method of decontaminating material is in accordance with aspects of the invention will now be illustrated. As shown in FIG. 1, contaminated material is removed from its existing location by well known conventional means as illustrated by removing conveyor 12 and into container 16. Feeder 18, which may be a pug mill, shredder, screen or the like, creates a seal between container 16 and sealed conveyor 20, accepts material from container 16 and deposits it in sealed conveyor 20. Contaminated material travels through sealed conveyor 20 upwardly into hopper 23 and then into the front end 22 of vapor stripping conveyor 24. Contaminated material 14 spills downwardly through the top of vapor stripping conveyor 24 and engages stripping conveyors 26. Stripping conveyors 26 are rotated by conventional means well known in the art and cause contaminated material 14 to move along the length of vapor stripping conveyor 24.
Stripping conveyors 26 receive heated heat transfer fluid, such as air, oil, water, steam, eutectic salts, Dowtherm®, gas and the like through hollow shafts 72 and optionally through flights 74. Heated heat transfer fluid is received from fluid supply line 28, which is heated in heater 32. The heated heat transfer fluid travels along hollow shafts 72 and exits vapor stripping conveyor 24 through fluid return line 30, which returns cooled heat transfer fluid to heater 32 for reheating. It is also possible for heat transfer fluid to be directed into the exterior walls and/or bottom of vapor stripping conveyor 24 if it is constructed to that capacity and if desired. This is especially true in the event conveyors, such as continuous belts or screens or the like, are substituted for rotating screw conveyors. Flowing heated heat transfer fluid through the exterior walls and/or bottom increases the heated surface exposed to the material, thereby enhancing vapor stripping in apparatus utilizing rotating screw conveyors and acting as the primary heat transfer vehicle in the case of alternate conveyors.
Contaminated material 14 travels through vapor stripping conveyor 24 by action of the rotating flights 74 and is heated as it progresses from one end to the other by absorbing heat from hollow shafts 72, flights 74 and optionally from the exterior walls and/or bottom of vapor stripping conveyor 24. Absorbed heat causes volatile and semivolatile hazardous organic contaminants contained within the material, as well as moisture contained in the material, to vaporize at points below their boiling temperatures. The combined vaporized organic compounds and water vapor travel upwardly into the open space within vapor stripping conveyor 24 above the material.
Because of the potentially toxic nature of the vaporized organic contaminants, it is necessary to ensure that all of the vaporized organics are carried away from vapor stripping conveyor 24. This has proven to be a difficult task for several reasons. One problem has been the need to ensure that vapor stripping conveyor 24 does not leak or permit fugitive toxic vapors to escape into the atmosphere.
Another severe problem encountered is the tendency of the material to dry out upon heating. However, this tendency defeats the goal of driving out substantially all (such as 99.99%, for example) of the hazardous organic contaminants contained in the material. Often in prior art apparatus, a dry crust tends to form on the surface of the material due to rapid heating on outer portions thereof, which forms into a vapor impermeable capsule around inner portions of the material. This prevents proper heating of all of the soil and results in trapped hazardous organics within the soil, thereby defeating the decontamination objective.
Yet another problem encountered in the prior art has been the extremely high flammability of many of the volatilized contaminants, especially under elevated temperatures. The danger of explosion has proven to be very real.
It has been surprisingly discovered that precise channeling of non-oxidative gases over the surface of the material solves the problem of undue drying of the surface portion of the material, which permits substantially all of the hazardous organic contaminants within the material to volatilize and escape. Use of non-oxidative gas has also virtually eliminated the possibility of fire and/or explosion despite the presence of substantial quantities of vaporized, highly flammable organic compounds within the stripping conveyor. It has further been surprisingly discovered that the particular manner of channeling gases inside the conveyor prevents fugitive vapor emissions from vapor stripping conveyor 24.
To solve the problems outlined above, non-oxidative gases, such as nitrogen, argon, steam and carbon dioxide, for example, are channeled from a non-oxidative gas supply in a special precise manner into vapor stripping conveyor 24. As shown in FIG. 1, gases such as nitrogen, argon or carbon dioxide and the like may be supplied from an on site non-oxidative gas source 44, through non-oxidative gas supply blower 42, into branch 40b, through non-oxidative gas supply line 40 and into non-oxidative gas feed lines 33, 34, 36, 38. These gases are preferably supplied at temperatures greater than ambient. In the alternative, exhaust gases generated by heater 32 in heating fluids for passage through vapor stripping conveyor 24 may be channeled through branch 40a and into non-oxidative gas supply line 40.
As shown in FIG. 2, non-oxidative gases are swept into vapor stripping conveyor 24 through openings in the side wall of the conveyor. The openings are preferably positioned at a point slightly above the surface of the material as it travels along the length of the conveyor. The non-oxidative gases are blown directly across the top of the material and received by vapor exhaust lines 46, 48, 50, 52 wherein they exit vapor stripping conveyor 24. Although the drawings show introduction and exit of the non-oxidative gases at right angles to the direction of travel of the material, such is not required so long as the non-oxidative gases sweep across the soil from side to side. It is possible to introduce and remove the non-oxidative gases at angles other than right angles so long as the critical "cross" sweep of the gases is maintained. Blowing non-oxidative gases perpendicular to the direction of material travel has proven to be the preferred method since this flow direction provides lower "face velocities" of the sweep gases. Lowered face velocities reduce sweep gas turbulence, which increases vapor removal efficiency and reduces dust production. Thus, a higher degree of material cleaning and decontamination can be achieved and emission control is enhanced.
Providing multiple gas inlets to cross-sweep vapors and moisture residing in the space above the material has proven to be an especially advantageous and effective way to remove vapors and moisture from the material as soon as the newly formed vapor emerges from the material. By providing multiple sweep gas inlets, the supply of fresh sweep gas ensures that the sweep gas does not become saturated prior to exiting vapor stripping conveyor 24. If the sweep gas becomes saturated before it exits the vapor stripping conveyor, it tends to permit lengthened contact of the hazardous vapors with the material, thereby endangering the effectiveness of material decontamination. It should be noted that although the drawings show four non-oxidative gas feed lines and four vapor exhaust lines, this is only a preferred construction. Use of more or fewer feed and exhaust lines is fully contemplated to fall within the scope of this invention.
It is also advantageous that the cross-sweep gases be introduced at a controlled temperature higher than the ambient temperature of the material entering the conveyor. For example, one preferred range of temperature includes those higher than the boiling point of water. Another especially preferred range includes temperatures greater than the boiling point of the volatile organic(s) to be removed. Use of higher than ambient temperature gases in combination with cross-sweeping the gases reduces the amount of hot gases contacting the material at the introduction point of the material when it is at its lowest temperature. This minimizes surface drying and crusting of the feed material, thereby enhancing vapor stripping.
Higher than ambient temperature sweep gases provide enhanced vapor and moisture absorbance by the sweep gases. Utilization of greater than ambient temperature sweep gases ensures that the vapors do not have an opportunity to condense prior to being swept out of the vapor stripping conveyor. Condensation of vapors is to be avoided because it recontaminates previously cleaned material. Greater than ambient temperatures also ensure increased partial pressures of the vapors to increase vapor absorbance. Another advantage of greater than ambient temperatures lies with reduced corrosion tendencies that normally result from acid-gas condensation at lower temperatures. Higher than ambient temperatures for the sweep gases still further increase the total thermal efficiency of the process.
After hazardous organic vapors and moisture exit vapor stripping conveyor 24, they travel through vapor exhaust lines 46, 48, 50, 52 and into vapor exhaust manifold 54. Vapor exhaust blower 58 conveys the mixture to vapor exhaust cleaner apparatus 60. Vapor exhaust cleaner apparatus 60 can be any decontamination apparatus well known in the art. For example, exhaust cleaner 60 may be capable of filtering to remove dust, scrubbing with wet scrubber 63 for removal of acid gases, burning the organics with burner 61, burning the organics with burner 61 followed by scrubbing with wet scrubber 63, absorbing a portion of the hazardous organics on activated carbon, catalytic thermal destruction with catalytic thermal destructor 65, recovering the hazardous organics by condensation with condenser 63 or recovering by condensation followed by absorption on activated carbon. All of these cleaning apparatus, as well as others, are well known in the art and are not described in detail herein. Cleaned gases may be exhausted into the atmosphere without danger to the surrounding environment through exhaust purge conduit 62 or may be recycled to non-oxidative gas source 44 for reuse by way of exhaust purge recycle conduit 64.
Referring now to FIG. 3 of the drawings, an alternative preferred embodiment of a method of performing the invention is described. Contaminated material 14 is removed from its existing location and transported on removing conveyor 12. Contaminated material 14 enters container 16, travels through feeder 18, sealed conveyor 20, hopper 23 and into vapor stripping conveyor 24 in the usual manner. Contaminated material 14 is decontaminated by volatilization of the volatile and semivolatile hazardous organics in the same manner as previously described in conjunction with the apparatus shown in FIGS. 1 and 2. However, instead of material exiting through chute 70 as shown in FIG. 1, the material exits vapor stripping conveyor 24 through transfer chute 76 and into a second vapor stripping conveyor 124 for further decontamination.
Introduction of cross-sweeping gases through non-oxidative gas feed lines 133, 134, 136, 138 may be performed in the same manner as through non-oxidative gas feed lines 33, 34, 36, 38. Similarly, a combination of hazardous organic volatile vapors, moisture and the non-oxidizing gas exits vapor stripping conveyor 124 through vapor exhaust lines 146, 148, 150, 152 in the same manner as vapor exhaust lines 46, 48, 50, 52 in vapor stripping conveyor 24. Utilization of the second set of cross-sweeping gas sources further ensures that materials passing through vapor stripping conveyor 124 are completely decontaminated prior to exiting chute 170.
However, it has surprisingly been discovered that excellent material decontamination may be achieved by not supplying further non-oxidative gas into vapor stripping conveyor 124. Instead, the flow of cross-sweep gases in vapor stripping conveyor 24 creates a venturi effect through transfer chute 76 and the space above the material in vapor stripping conveyor 124. This venturi effect creates a secondary sweep gas phenomenon in vapor stripping conveyor 124, which is particularly effective to achieve final decontamination of material passing therethrough.
Removal of as much as 99.99%, or more, of all volatile and semivolatile organic contaminants in various materials has been continuously achieved at high rates of treatment utilizing the apparatus and method of the invention claimed below. Table I illustrates the effectiveness of the claimed invention in four test runs conducted on soils containing volatile organic contaminants. Similarly, semivolatile organic contaminants were effectively removed in the same four test runs as shown in Table II.
The system 10 further contains various valves, dampers, gauges and the like that are not illustrated for the sake of simplicity and ease of understanding. They are employed to control or direct gases and/or fluids through the various conduits in the desired manner. Vapor stripping conveyor 24 has also been illustrated and described in a simplified manner for ease of understanding. For example, the number of flights 74 has been reduced below the number practically employed in use. Also, no specific means for rotating the flights has been shown. Although heating fluid entrances and exits for vapor stripping conveyor 24 have been illustrated as connecting at opposing ends, it should be understood that other constructions are possible, such as by use of standard, commercially available rotary joints. These design features are well known and may be commercially obtained in various forms and configurations. Moreover, conveying means other than rotating flights may be used to convey materials through vapor stripping conveyor 24.
Although this invention has been described with reference to specific forms selected for illustrations in the drawings, it will be appreciated that many modifications may be made, that certain steps may be performed independently of other steps, and that a wide variety of equivalent forms of apparatus may be utilized, all without departing from the spirit and scope of this invention, which is defined in the appended claims.
TABLE I__________________________________________________________________________ Test 1 Test 2 Test 4 Test 8 Oil Temperature 600° F. Oil Temperature 400° F. Oil Temperature 400° Oil Temperature 500° F. Residence Time 40 min. Residence Time 40 min. Residence Time 35 Residence Time 40 min. Soil Concentration Soil Concentration Soil Concentration Soil Concentration Feed Processed Feed Processed Feed Processed Feed ProcessedAnalyte (ug/kg) (ug/L) (a) (ug/kg) (ug/L) (a) (ug/kg) (ug/L) (a) (ug/kg) (ug/L)__________________________________________________________________________ (a)VolatilesVinyl chloride <3,500 0.2 <3,600 0.2 <1,600 0.2 <1,600 0.2Dichloromethane <1,800 0.1 <1,800 0.1 <800 0.1 <800 0.11,1-Dichloroethene <1,800 0.1 <1,800 0.1 <800 0.1 <800 0.1Chloroform 140 J 0.1 180 J 0.1 <800 0.1 <800 0.11,2-Dichloroethane <1,800 0.1 <1,800 0.1 <800 0.1 <800 0.11,1,1-Trichloroethane <1,800 0.1 <1,800 0.1 <800 0.1 <800 0.1Trichloroethene 37,250 0.3 111,000 (b) 0.3 10,575 1.2 8,500 2.3Tetrachloroethene 2,760 J 0.1 3,985 J 0.1 613 J 0.0 650 J 0.12-Butanone <11,000 0.6 <11,000 0.6 <4,800 0.6 <4,800 0.6Benzene* <1,800 0.1 <1,800 0.1 745 J 0.1 136 J 0.4Toluene* <1,800 0.1 8,300 0.1 200 J 0.1 18 J 0.0Chlorobenzene* <1,800 0.1 <1,800 0.1 <800 0.1 <800 0.1Ethylbenzene* <1,800 0.1 960 J 0.1 <800 0.1 <800 0.1__________________________________________________________________________ (a) TCLP concentrations. TCLP extract for VOCs was determined by dividing soil concentration by 20, thus simulating a worstcase leachate scenario (all contaminants leached by TCLP). (b) Higher than detection range, estimated value. Replicate indicated an estimated value less than detection limit, however, sample replicate integrity is suspect. *Potential constituent of JP4 fuel. <Not detected at the specified detection limit. J Less than detection limit, estimated value.
TABLE II__________________________________________________________________________ Test 1 Test 2 Test 4 Test 8 Oil Temperature 600° F. Oil Temperature 400° F. Oil Temperature 400° F. Oil Temperature 500° F. Residence Time 40 min. Residence Time 40 min. Residence Time 35 min. Residence Time 40 min. Soil Concentration Soil Concentration Soil Concentration Soil Concentration Feed Processed Feed Processed Feed Processed Feed ProcessedAnalyte (ug/kg) (ug/L) (a) (ug/kg) (ug/L) (a) (ug/kg) (ug/L) (a) (ug/kg) (ug/L)__________________________________________________________________________ (a)Semivolatiles1,2-Dichlorobenzene 35,000 6 J 15,000 10 J 53,000 6 J 13,500 4 J1,4-Dichlorobenzene 8,700 6 J 3,600 J <100 14,750 1 J 4,300 J 1 JFluoranthene* <3,300 <10 2,900 J <100 1,750 J 10 J 795 J <20Benzo(a)anthracene* <3,300 <10 <3,800 <100 <3,900 <10 <4,300 <20Benzo(a)pyrene* <3,300 <10 <3,800 <100 <3,900 <10 <4,300 <20Benzo(b)fluoroanthene* <3,300 <10 <3,800 <100 <3,900 <10 <4,300 <20Chrysene* <3,300 <10 <3,800 <100 <3,900 10 J <4,300 <20Dibenzo(a,h)anthracene* <3,300 <10 <3,800 <100 <3,900 10 J <4,300 <20Acenaphthene* <3,300 <10 <3,800 <100 <3,900 10 J <4,300 <20Acenaphthylene* <3,300 <10 <3,800 <100 370 J 10 J <4,300 <20Anthracene* 60 J <10 770 J <100 120 J 10 J <4,300 <20Benzo(g,h,i)perylene* <3,300 <10 <3,800 <100 <3,900 <10 <4,300 <20Fluorene* <3,300 <10 < 3,800 <100 325 J <10 <4,300 <20Indeno(1,2,3-c,d)pyrene* <3,300 <50 <3,800 <500 <20,000 <50 <22,000 <100Phenanthrene* 790 J <10 820 J <100 960 J 1 J 320 J <20Pyrene* 280 J <10 90 J <100 785 J <10 185 J <20Benzo(k)fluoranthene* <3,300 <10 <3,800 <100 <3,900 <10 <4,300 <20__________________________________________________________________________ (a) TCLP concentrations. TCLP extract for VOCs was determined by dividing soil concentration by 20, thus simulating a worstcase leachate scenario (all contaminants leached by TCLP). (b) Higher than detection range, estimated value. Replicate indicated an estimated value less than detection limit, however, sample replicate integrity is suspect. *Potential constituent of JP4 fuel. <Not detected at the specified detection limit. J Less than detection limit, estimated value.
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Method and apparatus for removing organic contaminants from contaminated materials including a sealed hopper, a heated vapor stripping conveyor sealed from atmospheric air to vapor strip the contaminants from the material, a sealed conveyor to convey the material in sealed condition from the hopper to the vapor stripping conveyor, a supply of non-oxidative gases at a controlled temperature for introduction into the vapor stripping conveyor, an introduction portal for the non-oxidative gases into the vapor stripping conveyor, an exit for removing the non-oxidative gases from the conveyor and located to cause the non-oxidative gases to cross currently sweep over the material to convey contaminants and moisture stripped from the material out of the vapor stripping conveyor, and a controller for controlling the flow rate and temperature of the non-oxidative gases as they flow through the vapor stripping conveyor and to prevent undue surface drying of the material as the material passes through the vapor stripping conveyor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to chain stitch sewing machines and more particularly to actuating mechanisms for double pointed loopers in such machines.
2. Description of the Prior Art
Single thread chain stitch sewing machines utilizing double pointed loopers are commonly used in machines for sewing buttons onto garments and sewing a series of substantially superimposed stitches for tacking together multiple pieces of material. Various means have been utilized in such machines for driving the double pointed loopers so as to alternately place each of the two loops seizing points into cooperative association with a sewing needle as required to provide for the formation of chain stitches. However, the looper actuating mechanisms employed heretofore have generally been structurally complex as well as costly to produce, and have frequently failed in use.
It is a prime object of the present invention to provide a double pointed looper in a sewing machine with improved actuating mechanism which is simple in construction, has few parts, and is inexpensive to manufacture as well as maintain.
It is another object of the invention to provide a double pointed looper in a sewing machine with improved actuating mechanism as described which is reliable in operation.
Other objects and advantages of the invention will become apparent hereinafter during a reading of the specification taken in connection with the accompanying drawings.
SUMMARY OF THE INVENTION
A chain stitch sewing machine including a double pointed looper is provided with camming means including two intersecting cam tracks and an actuator to slidingly engage the tracks alternately and move the looper so as to place each of the two loop seizing points alternately in cooperative engagement with the needle as required to provide for the formation of chain stitches on the machine. A gate movable with respect to the cam tracks includes a part which extends between the tracks at their intersection. The actuator while in each track moves the gate from a held position wherein the entrance to the track with the actuator therein is open and the entrance in the other track is closed by the extending gate part, to another held position wherein the entrance to the track with the actuator therein is closed by the extending gate part and the entrance to the other track is open. The extending gate part is resiliently movable with respect to another part of the gate and the actuator can exit from each track by temporarily moving the extending gate part from its position closing the entrance thereto.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sewing machine incorporating looper controlling mechanism according to the invention;
FIG. 2 is an exploded perspective view showing the looper mechanism;
FIGS. 3, 4, 5, 6, 7, 8 and 9 are end views of the looper controlling mechanism shown in various operating positions;
FIG. 10 is a side view showing a needle approaching the looper;
FIG. 11 is similar to FIG. 10 but showing the needle and looper in engagement.
FIG. 12 is an enlarged end view, partially in section, showing a modified gate construction for the looper mechanism;
FIGS. 13 and 14 are enlarged end and side views respectively showing another modified gate construction.
FIG. 15 is an enlarged end view showing still another modified gate construction, and
FIGS. 16 and 17 are enlarged end and side views respectively showing yet another modified gate construction.
DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 through 11, there is shown a hand held sewing machine 10 including a frame 12, a thread carrying needle 14 arranged for reciprocating movement and a pivotally movable looper 16 with opposing loop seizing points 17 and 19 which cooperate with the needle in the formation of chain stitches. A work piece feed mechanism 18 is arranged to undergo movements in cooperation with those of the needle 14 and the looper 16 in a well known manner, to properly position the work piece. A hand operated lever 20 which is pivotally attached at one end 22 to the frame 12 is interconnected with the needle 14 and feed mechanism 18 to impart the desired movements thereto. Such interconnections are well known in the sewing machine art and therefore shall not be detailed here.
The hand operated lever 20 acting through a drive arm 24, an actuator in the form of a drive pin 26 on the arm, and a pivoted cam 28 driven by the actuator as hereinafter described also imparts movement to the looper 16. As shown, the drive pin 26 is held in place on the free end portion 30 of arm 24 by a suitable fastener 32, and extends through an elongated hole 34 in a guide block 36 which is rigidly attached to the frame 12, the elongated hole being arranged to slidingly receive drive pin 26 for the guiding thereof in a vertical plane. The drive pin further extends beyond the guide block to the cam 28 to provide for the actuation of the cam and thereby the looper 16 which is affixed to the cam with screw fasteners 38 and 40 that are threaded into holes 42 and 43 respectively in the cam.
Cam 28 with attached looper 16 (designated in the drawings as assembly 82) is pivotally attached to the guide block 36 with a screw fastener 44 which is threaded into a hole 46 formed in the guide block. A helical compression spring 48 disposed between the head of the screw fastener 44 and the looper 16 urges the cam and looper toward the guide block so that the surface 50 of the cam is maintained in sliding engagement with the guide block. The cam includes two cam tracks 52 and 54 which intersect at their lower extremities and receive an end portion of the drive pin 26 extending through elongate hole 34 in block 36. Pin 26 which is vertically reciprocated by operation of handle 20 moves along the tracks to impart reciprocatory motion to the cam.
A gate 58 is pivotally mounted at 59 in a recessed portion 60 of the cam on a fixed pin 62. The gate is a molded plastic member including a triangularly shaped depending part 64 which extends between the tracks 52 and 54 at their intersection. Depending part 64 connects through a thin flexible section 66 with another part 68 including springy appendages 70 and 72 that serve to resiliently resist movement of the depending gate part 64 relative to part 68. Gate part 68 is formed along a curved edge 74 with spaced apart notches 76 and 78 wherein a resilient pin 80 affixed in the gate is receivable.
FIGS. 3 through 9 inclusive illustrate the operation of cam 28, gate 58 and looper 16 in response to vertical movement of the drive pin 26. In FIG. 3 drive pin 26 may be seen at one end of its excursion in the upper end of track 52. The cam 28 and attached looper 16 are then cocked to the left with respect to the path of travel of pin 26, and the gate 58 is latched by resilient pin 80 in notch 78 in a position wherein depending gate port 64 extends across the lower end of the track 52 at the intersection of track 52 with track 54.
Pin 26 moves downwardly from its upper end position, and as it slides along the cam track 52 imparts clockwise movement to the cam and looper assembly 82 about screw 44. The pin moves gate part 64 aside against the bias of spring appendage 72 to enter the track intersecting region 84 (FIG. 4), and then passes into the lower extremity 86 of region 84 whereupon the gate part 64 is returned by spring appendage 72 to its position across the lower end of track 52 so as to block the entrance to track 52 and unblock the entrance to track 54 (FIG. 5).
Pin 26 moves upwardly from a lower end position in the lower extremity 86 of track intersecting region 84 and enters unblocked track 54 (FIG. 6). The pin moves toward the upper end of track 54 and causes the cam and looper assembly 82 to be moved in a clockwise direction. In addition, the pin by engaging the gate part 68 in track 54 causes the gate 58 to be moved in a clockwise direction about pivot pin 62 from the latched position with pin 80 in notch 78 to a position wherein pin 80 is caused to enter notch 76 and depending gate part 64 is caused to extend across the lower end of track 54 (FIG. 7) instead of track 52.
The drive pin 26 moves downwardly from an upper end position in the upper end of track 54 causing assembly 82 to be moved in a counterclockwise direction, and at the bottom of the track the pin pushes depending portion 64 of gate 58 aside against the bias of spring appendage 70 to enter the intersection between the tracks (FIG. 8) and then pass into the lower extremity thereof, after which gate part 64 is returned to its position across the lower end of track 54 so as to block the entrance to such track and to unblock the entrance to track 52 (FIG. 9).
The drive pin moves upwardly from the intersecting track region into track 52 and then along track 52 wherein the pin is effective to urge assembly 82 further in a counterclockwise direction and wherein the pin comes into engagement with cam 58 causing it to be moved back to the position wherein latch pin 80 registers in notch 78 and depending gate part 64 extends across the lower end of track 52. After pin 26 reaches the upper end of track 52 (FIG. 3) the described operational cycle of the cam and looper assembly 82 is repeated in response to continued vertical reciprocation of the pin.
The gate may be variously constructed so as to include a depending part resiliently movable relative to another part which is engageable by a drive pin in the cam tracks 52 and 54. Examples of different constructions may be seen in FIGS. 12 through 17 wherein parts generally similar to those on gate 58 are designated with corresponding reference characters having a subscript added thereto. In the gate 58a shown in FIG. 12, the depending gate part 64a is a separate member which pivotally mounts at 59a on the cam affixed pin 62 along with the other part 68a of the gate engageable in the cam tracks 52 and 54 by the drive pin 26. A spring 88 extending around a fixed pin 90 on gate part 68a and over another fixed pin 91 thereon has free end portions 92 and 94 in engagement with a bulb 95 at the end of a flanged extension 96 on the said gate part 64a. The spring biases gate part 68a toward a centralized position on gate part 64a, but permits gate part 68a to be moved relative to gate part 64a by drive pin 26 when exiting from a cam track.
In the gate 58b shown in FIGS. 13 and 14, the depending gate part 64b is keyed at 97 to gate part 68b which pivotally mounts at 59b on the cam affixed pin 62. Gate part 64b is formed of a resilient sheet material such as sheet steel and has free ended legs which can be flexed from a normal position, as illustrated, by the drive pin 26 when exiting from a cam track and which will return to such normal position after passage of the pin.
FIG. 15 shows a one-piece molded plastic gate 58c with a depending part 64c which connects with the other part 64b of the gate through resiliently foldable, thin zig-zag sections 98 and 100 that serve as centering springs for part 64c.
In FIGS. 16 and 17 there is shown a one piece molded plastic gate 58d on which a front depending part 64d connects with a rear part 68d through thin, resilient walls 102, 104, 106 and 108 formed in the gate in the plane of depending part 64d. The thin walls 102, 104, 106 and 108 normally maintain the depending part 64d in a centralized position on the gate and return part 64d to such position after removal therefrom. The entire gate 58d is pivoted by engagement with drive pin 26 along side edges 110 and 112 on gate part 68d.
It is to be understood that the present disclosure relates to preferred embodiment of the invention which are for purposes of illustration only and are 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.
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A sewing machine is provided with a double pointed looper and actuating mechanism therefore including a double tracked cam, an actuator operable on the cam tracks, and a gate with a resiliently movable portion for controlling movement of the actuator between the cam tracks.
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BACKGROUND
[0001] 1. Field of Invention
[0002] This application relates to three-dimensional (3D) woven composites with high specific energy absorption (SEA) that significantly outperform traditional 2D laminated composites enabling the manufacturing of 3D woven composite parts that can replace ones made from traditional materials such as laminated composites or high strength metals, at a lighter weight.
[0003] 2. Description of Related Art
[0004] Due the presence of through-thickness reinforcement, 3D woven composites have superior fracture toughness, fatigue life, and damage tolerance compared to laminated composites. Furthermore, 3D woven composites exhibit a progressive damage behavior that is more benign than the typical catastrophic failure behavior of laminated composites. These properties lead to high specific energy absorption (SEA)—an industry accepted common measure of energy absorbed by destructed weight of a specimen or part—enabling the manufacturing of 3D woven composite parts that can replace ones made from traditional materials such as laminated composites or high strength metals, at a lighter weight.
SUMMARY OF THE DISCLOSURE
[0005] The present disclosure provides 3D woven preforms that can be impregnated with a matrix material to form composites that significantly outperform traditional 2D laminated composites. The presently disclosed technology can be used to make parasitic or load-bearing structural components for improved crashworthiness of vehicles (land, water, or air). “Parasitic” is a term commonly used in composites. “Parasitic” in this context means a component used only for the purpose of energy absorption. Applications of the presently disclosed technology can range from sacrificial crash tubes to multi-purpose structural components.
[0006] In the disclosed 3D ply-to-ply woven preforms, each warp fiber ties the weft layer below or above it. As such, the 3D woven composite—a preform impregnated with a matrix material—can provide through thickness reinforcement that does not exist in laminated composites and also can reduce delamination as a mode of composite failure because no plane exists within the composite that a reinforcement yarn (warp or weft) does not cross. The lack of such planes act to stop the propagation of cracks through the structure hence increasing the amount of force and energy required to crush the 3D composite.
[0007] In one embodiment a three-dimensional (3D) composite article includes a 3D woven preform. The preform has a plurality of warp yarns and a plurality of weft yarns. The warp yarns are woven with the weft yarns to form a structure having a plurality of layers of the 3D woven preform. The 3D woven composite article has a specific energy absorption (SEA) greater than a 2D woven laminated preform of substantially the same weight, when each preform is impregnated with a matrix material to form the composite article.
[0008] In some implementations the 3D woven composite article has the specific energy absorption (SEA) at least 10% greater than a 2D woven laminated preform of substantially the same weight. In other implementations the 3D composite article has the specific energy absorption (SEA) at least 20% greater than a 2D woven laminated preform of substantially the same weight.
[0009] Also disclosed is a three-dimensional (3D) woven preform. The preform has a plurality of warp yarns and a plurality of welt yarns. The warp yarns are woven with the weft yarns to form a structure having a plurality of layers of the 3D woven preform. The one or more warp yarns selected from the plurality of warp yarns in a particular layer are first binder yarns that bind weft yarns in the particular layer to weft yarns in a another layer, and the one or more weft yarns selected from the plurality of weft yarns in the particular layer are second binder yarns that bind warp yarns in the particular layer to warp yarns in the another layer.
[0010] Also, disclosed is a method of forming a three-dimensional (3D) woven composite article by forming a 3D woven preform. The preform is formed by weaving a plurality of warp yarns with a plurality of weft yarns to form a structure having a plurality of layers of the 3D woven preform. The 3D woven composite has a specific energy absorption (SEA) greater than a 2D woven laminated preform of substantially the same weight, when each preform is impregnated with a matrix material to form the composite article.
[0011] The method of forming a three-dimensional (3D) woven composite article can also include binding weft yarns in a particular layer to weft yarns in another layer with first binder yarns, the first binder yarns being one or more warp yarns selected from the plurality of warp yarns in the particular layer, and also binding warp yarns in a particular layer to warp yarns in the another layer with second binder yarns, the second binder yarns being one or more weft yarns selected from the plurality of weft yarns in the particular layer.
[0012] In some implementations the preform has the specific energy absorption (SEA) at least 10% greater than the 2D woven laminated preform of substantially the same weight. In other implementations the preform has the specific energy absorption (SEA) at least 20% greater than the 2D woven laminated preform of substantially the same weight.
[0013] Further, a method of forming a three-dimensional (3D) woven preform includes weaving a plurality of warp yarns with a plurality of weft yarns to form a structure having a plurality of layers of the 3D woven preform. One or more warp yarns selected from the plurality of warp yarns in a particular layer are first binder yarns that bind weft yarns in the particular layer to weft yarns in a another layer, and one or more weft yarns selected from the plurality of weft yarns in the particular layer are second binder yarns that bind warp yarns in the particular layer to warp yarns in the another layer.
[0014] It is noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as “comprises”, “comprised”, “comprising” and the like can have the meaning attributed to it in U.S. patent law; e.g., they can mean “includes”, “included”, “including”, and the like.
[0015] The above and other objects, features, and advantages of various embodiments as set forth in the present disclosure will be more apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A illustrates an example of 3D woven preform ply-to-ply architecture 3D-P1-50 of the present disclosure.
[0017] FIG. 1B illustrates a cross sectional plane A along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0018] FIG. 1C illustrates a cross sectional plane B along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0019] FIG. 1D illustrates a cross sectional plane C along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0020] FIG. 1E illustrates a cross sectional plane D along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0021] FIG. 1F illustrates a cross sectional plane E along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0022] FIG. 1G illustrates a cross sectional plane F along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0023] FIG. 1H illustrates a cross sectional plane G along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0024] FIG. 1I illustrates a cross sectional plane H along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A .
[0025] FIG. 2 illustrates a single warp column of the 3D woven preform architecture 3D-P1-70.
[0026] FIG. 3 illustrates a single warp column of the 3D woven preform architecture 3D-P2-50.
[0027] FIG. 4 illustrates a single warp column of the 3D woven preform architecture 3D-O50.
[0028] FIG. 5 illustrates a single warp column of the 3D woven preform architecture 3D-O70.
[0029] FIG. 6 illustrates corrugated composite test specimen before, during, and after testing.
[0030] FIG. 7 illustrates a quasi-static SEA comparison of all eight configurations tested with 3D woven composites and 2D laminated composites.
[0031] FIG. 8 illustrates a chart comparing rate dependent SEA values for four configurations.
[0032] FIG. 9 illustrates four variants of a possible automotive application for the development of a 3D woven composite longitudinal component.
DETAILED DESCRIPTION
[0033] The terms “threads”, “fibers”, and “yarns” are used interchangeably in the following description. “Threads”, “fibers”, and “yarns” as used herein can refer to monofilaments, multifilament yarns, twisted yarns, multifilament tows, textured yarns, braided tows, coated yarns, bicomponent monofilament yarns, as well as yarns made from stretch broken fibers or any other such materials.
[0034] FIGS. 1A and 2-5 illustrate five examples of cross sectional planes of 3D woven structures, which differ in the amount of through-thickness reinforcement and the balance of the number of fibers in the warp and weft direction (also known as warp/weft ratio). Each layer in the structure is formed by weaving warp and weft fibers. The warp/weft ratio here indicates the warp percentage by volume of the total fiber. The warp/weft ratio may be used to quantify the percentage of yarns in the warp and weft directions, and tailored for performance reasons (i.e., stiffness and strength). The 3D woven preforms in FIGS. 1A, 2, and 3 , which are 3D-P1-50, 3D-P1-70, and 3D-P2-50, respectively, are three variations of ply-to-ply architectures denoted by 3D-P. The 3D woven preforms in FIGS. 4 and 5 , which are 3D-O50 and 3D-O70, respectively, are two variations of orthogonal weaves with higher through-thickness reinforcement. The 50 or 70 refer to the warp/weft ratio, i.e., the warp percentage by volume of the total fiber.
[0035] FIG. 1A illustrates an example of 3D woven preform ply-to-ply architecture 3D-P1-50 of the present disclosure. The 3D woven perform 3D-P1-50 is a ply-to-ply standard crimp 3D weave with 50/50% warp/weft ratio. FIG. 1B illustrates a cross sectional plane A along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane A includes warp threads 110 , 111 , 112 , 113 . . . 117 , and 118 . As shown in FIG. 1B , during the weaving of the 3D woven preform, first warp thread 110 in the first layer is woven over the weft thread 150 in the first layer, then under the weft thread 160 , then under the weft thread 171 , and finally under the weft thread 180 . Therefore, the first weft row that includes weft threads 150 , 160 , 170 , and 180 , and the second weft row that includes weft threads 151 , 161 , 171 , and 181 , are tied to each other in the cross sectional plane A. In a similar manner, in the next weft row, the second warp thread 111 in the second layer is woven over the weft thread 151 in the second layer, then under the weft thread 161 , then under the weft thread 172 , and finally under the weft thread 181 . Therefore, the second weft row that includes weft threads 151 , 161 , 171 , and 181 , and the third weft row that includes weft threads 152 , 162 , 172 , and 182 , are tied to each other in the cross sectional plane A. The other warp threads in the cross sectional plane A, i.e., 112 , 113 . . . 117 , and 118 are all woven in the pattern similar to warp threads 110 and 111 . Therefore, each weft row and a subsequent weft row are tied to each other in the cross sectional plane A. FIG. 1C illustrates a cross sectional plane B along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane B includes warp threads 120 , 121 , 122 . . . 128 . As shown in FIG. 1C , during the weaving of the 3D woven preform, the warp thread 120 in the first layer is woven under the weft thread 150 , then over the weft thread 160 in the first layer, then under the weft thread 170 , and finally under the weft thread 181 . Therefore, the first weft row that includes weft threads 150 , 160 , 170 , and 180 , and the second weft row that includes weft threads 151 , 161 , 171 , and 181 , are tied to each other in the cross sectional plane B. In a similar manner, in the next weft row, the warp thread 121 is woven under the weft thread 151 , then over the weft thread 161 , then under the weft thread 171 , and finally under the weft thread 182 . Therefore, the second weft row that includes weft threads 151 , 161 , 171 , and 181 , and the third weft row that includes weft threads 152 , 162 , 172 , and 182 , are tied to each other in the cross sectional plane B. The other warp threads in the cross sectional plane A, i.e., 122 , 123 . . . 128 are all woven in the pattern similar to warp threads 120 and 121 . Therefore, each weft row and a subsequent weft row are tied to each other in the cross sectional plane B.
[0036] FIG. 1D illustrates a cross sectional plane C along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane C includes warp threads 130 , 131 , 132 . . . 138 . As shown in FIG. 1D , during the weaving of the 3D woven preform, the warp thread 130 in the first layer is woven under the weft thread 151 in the second layer, then under the weft thread 160 , then over the weft thread 170 , and finally under the weft thread 180 . Therefore, the first weft row that includes weft threads 150 , 160 , 170 , and 180 , and the second weft row that includes weft threads 151 , 161 , 171 , and 181 , are tied to each other in the cross sectional plane C. In a similar manner, in the next weft row, the warp thread 131 is woven under the weft thread 152 , then under the weft thread 161 , then over the weft thread 171 , and finally under the weft thread 181 . Therefore, the second weft row that includes weft threads 151 , 161 , 171 , and 181 , and the third weft row that includes weft threads 152 , 162 , 172 , and 182 , are tied to each other in the cross sectional plane C. The other warp threads in the cross sectional plane A, i.e., 132 . . . 138 are all woven in the pattern similar to warp threads 130 and 131 . Therefore, each weft row and a subsequent weft row are tied to each other in the cross sectional plane C.
[0037] FIG. 1E illustrates a cross sectional plane D along the warp threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane D includes warp threads 140 , 141 , 142 . . . 148 . As shown in FIG. 1E , during the weaving of the 3D woven preform, the warp thread 140 in the first layer is woven under the weft thread 150 in the first layer, then under the weft thread 161 , then under the weft thread 170 , and finally over the weft thread 180 . Therefore, the first weft row that includes weft threads 150 , 160 , 170 , and 180 , and the second weft row that includes weft threads 151 , 161 , 171 , and 181 , are tied to each other in the cross sectional plane D. In a similar manner, in the next weft row, the warp thread 141 is woven under the weft thread 151 , then under the weft thread 162 , then under the weft thread 171 , and finally over the weft thread 181 . Therefore, the second weft row that includes weft threads 151 , 161 , 171 , and 181 , and the third weft row that includes weft threads 152 , 162 , 172 , and 182 , are tied to each other in the cross sectional plane D. The other warp threads in the cross sectional plane A, i.e., 142 . . . 148 are all woven in the pattern similar to warp threads 140 and 141 . Therefore, each welt row and a subsequent weft row are tied to each other in the cross sectional plane D. In these examples 1B-1E weft fibers of a particular layer or row are tied to weft fibers of the “subsequent weft layer”, which is the adjacent next layer to the particular warp layer being described. However, the term “subsequent weft layer” is used only for ease of description of the figures and is meant to be interpreted more broadly. In particular, as used herein “subsequent weft layer” means “another weft layer.” And such subsequent weft row or layer can be the adjacent next weft row or layer or multiple weft rows or layers distant, above or below, from the particular warp row or layer being described.
[0038] FIG. 1F illustrates a cross sectional plane E along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane E includes weft threads 150 , 151 , 152 . . . 159 . As shown in FIG. 1F , during the weaving of the 3D woven preform, the weft thread 151 in the second layer is woven over the warp thread 141 in the second layer, then over the warp thread 130 , then over the warp thread 121 , and finally under the warp thread 111 . Therefore, the first warp row that includes warp threads 140 , 130 , 120 , and 110 , and the second warp row that includes warp threads 141 , 131 , 121 , and 111 , are tied to each other in the cross sectional plane E. In a similar manner, in the next warp row, the weft thread 152 is woven over the warp thread 142 , then over the warp thread 131 , then over the warp thread 122 , and finally under the warp thread 112 . Therefore, the second warp row that includes warp threads 141 , 131 , 121 , and 111 , and the third warp row that includes warp threads 142 , 132 , 122 , and 112 , are tied to each other in the cross sectional plane E. The other weft threads in the cross sectional plane A, i.e., 153 . . . 159 are all woven in the pattern similar to weft threads 150 and 151 . Therefore, each warp row and a subsequent warp row are tied to each other in the cross sectional plane E. FIG. 10 illustrates a cross sectional plane F along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane F includes weft threads 160 , 161 , 162 . . . 169 . As shown in FIG. 1G , during the weaving of the 3D woven preform, the weft thread 161 in the second layer is woven over the warp thread 140 in the first layer, then over the warp thread 131 , then under the warp thread 121 , and finally over the warp thread 111 . Therefore, the first warp row that includes warp threads 140 , 130 , 120 , and 110 , and the second warp row that includes warp threads 141 , 131 , 121 , and 111 , are tied to each other in the cross sectional plane F. In a similar manner, in the next warp row, the weft thread 162 is woven over the warp thread 141 , then over the warp thread 132 , then under the warp thread 122 , and finally over the warp thread 112 . Therefore, the second warp row that includes warp threads 141 , 131 , 121 , and 111 , and the third warp row that includes warp threads 142 , 132 , 122 , and 112 , are tied to each other in the cross sectional plane F. The other weft threads in the cross sectional plane A, i.e., 163 . . . 169 are all woven in the pattern similar to weft threads 160 and 161 . Therefore, each warp row and a subsequent warp row are tied to each other in the cross sectional plane F.
[0039] FIG. 1H illustrates a cross sectional plane G along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane G includes weft threads 170 , 171 , 172 . . . 179 . As shown in FIG. 1H , during the weaving of the 3D woven preform, the weft thread 171 in the second layer is woven over the warp thread 141 in the second layer, then under the warp thread 131 , then over the warp thread 121 , and finally over the warp thread 110 . Therefore, the first warp row that includes warp threads 140 , 130 , 120 , and 110 , and the second warp row that includes warp threads 141 , 131 , 121 , and 111 , are tied to each other in the cross sectional plane G. In a similar manner, in the next warp row, the weft thread 172 is woven over the warp thread 142 , then under the warp thread 132 , then over the warp thread 122 , and finally over the warp thread 111 . Therefore, the second warp row that includes warp threads 141 , 131 , 121 , and 111 , and the third warp row that includes warp threads 142 , 132 , 122 , and 112 , are tied to each other in the cross sectional plane F. The other weft threads in the cross sectional plane A, i.e., 173 . . . 179 are all woven in the pattern similar to weft threads 170 and 171 . Therefore, each warp row and a subsequent warp row are tied to each other in the cross sectional plane G.
[0040] FIG. 1I illustrates a cross sectional plane H along the weft threads of the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A . The cross sectional plane H includes weft threads 180 , 181 , 182 . . . 189 . As shown in FIG. 1I , during the weaving of the 3D woven preform, the weft thread 181 in the second layer is woven under the warp thread 141 in the second layer, then over the warp thread 131 , then over the warp thread 120 , and finally over the warp thread 111 . Therefore, the first warp row that includes warp threads 140 , 130 , 120 , and 110 , and the second warp row that includes warp threads 141 , 131 , 121 , and 111 , are tied to each other in the cross sectional plane G. In a similar manner, in the next warp row, the weft thread 182 is woven under the warp thread 142 , then over the warp thread 132 , then over the warp thread 121 , and finally over the warp thread 112 . Therefore, the second warp row that includes warp threads 141 , 131 , 121 , and 111 , and the third warp row that includes warp threads 142 , 132 , 122 , and 112 , are tied to each other in the cross sectional plane F. The other weft threads in the cross sectional plane A, i.e., 183 . . . 189 are all woven in the pattern similar to weft threads 180 and 181 . Therefore, each warp row and a subsequent warp row are tied to each other in the cross sectional plane H.
[0041] In these examples 1F-1I warp fibers of a particular layer or row are tied to warp fibers of the “subsequent warp layer”, which is the adjacent next layer to the particular weft layer being described. However, the term “subsequent warp layer” is used only for ease of description of the figures and is meant to be interpreted more broadly. In particular, as used herein “subsequent warp layer” means “another warp layer.” And such a subsequent warp row or layer can be the adjacent next warp row or layer or multiple warp rows or layers distant, above or below, from the particular weft row or layer being described.
[0042] FIG. 2 illustrates a single warp column, i.e., a single cross sectional plane along the warp threads of the 3D woven preform architecture 3D-P1-70. The 3D woven perform 3D-P1-70 is a ply-to-ply standard crimp 3D weave with 70/30% warp/weft ratio. Compared with the 3D-P1-50 shown in FIG. 1A , in the 3D-P1-70 preform, there are two warp threads 210 and 211 in the first layer, and two warp threads 215 and 216 in the last layer, and the distance between weft yarn columns is greater than the distance in the 3D-P1-50 preform. These combined differences achieve a 70% warp percentage while maintaining the same target total fiber volume fraction in the 3D-P-50 preform.
[0043] Similar to the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A , in the 3D woven preform architecture 3D-P1-70 there are more cross sectional planes (not shown) that are only different by a shift in the pattern by a weft column.
[0044] As shown in FIG. 2 , the cross sectional plane includes warp threads 210 , 211 , 212 . . . 218 . As shown in FIG. 2 , during the weaving of the 3D woven preform, the warp threads 210 and 211 are woven over the weft thread 250 , then under the weft thread 260 , then under the weft thread 271 , and finally under the weft thread 280 . Therefore, the first weft row that includes weft threads 250 , 260 , 270 , and 280 , and the second weft row that includes weft threads 251 , 261 , 271 , and 281 , are tied to each other in the cross sectional plane. In a similar manner, in the next weft row, the warp thread 212 is woven over the weft thread 251 , then under the weft thread 261 , then under the weft thread 272 , and finally under the weft thread 281 . Therefore, the second weft row that includes weft threads 251 , 261 , 271 , and 281 , and the third weft row that includes weft threads 252 , 262 , 272 , and 282 , are tied to each other in the cross sectional plane. The warp threads 213 , 214 , and 215 are woven in the pattern similar to warp thread 212 , and the warp threads 216 and 217 are woven in the pattern similar to warp thread 210 and 211 . Therefore, each weft row and a subsequent weft row are tied to each other in the cross sectional plane.
[0045] FIG. 3 illustrates a single warp column, i.e., a single cross sectional plane along the warp threads of the 3D woven preform architecture 3D-P2-50. The 3D woven perform 3D-P2-50 is a ply-to-ply low crimp 3D weave with 50/50% warp/weft ratio. In the 3D-P2-50 preform, lower crimp is achieved through alternating weft yarn counts in each weft column. Similar to the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A , in the 3D woven preform architecture 3D-P2-50 there are more cross sectional planes (not shown) that are only different by a shift in the pattern by a weft column.
[0046] As shown in FIG. 3 , the cross sectional plane includes warp threads 310 , 311 . . . 314 , and 315 . As shown in FIG. 3 , during the weaving of the 3D woven preform, the warp thread 310 is woven over the weft thread 320 , then over the weft thread 330 , then under the weft thread 340 , then under the weft thread 350 , then under the weft thread 361 , then under the weft thread 370 , then under the weft thread 380 , and finally over the weft thread 390 . Therefore, the first weft row that includes weft threads 320 , 330 . . . 380 , and 390 , and the second weft row that includes weft threads 321 , 331 . . . 381 , and 391 , are tied to each other in the cross sectional plane. In a similar manner, in the next weft row, the warp thread 311 is woven over the weft thread 321 , then over the weft thread 331 , then under the weft thread 341 , then under the weft thread 351 , then under the weft thread 362 , then under the weft thread 371 , then under the weft thread 381 , and finally over the weft thread 391 . Therefore, the second weft row that includes weft threads 321 , 331 . . . 381 , and 391 , and the third weft row that includes weft threads 322 , 332 . . . 392 , are tied to each other in the cross sectional plane. Other warp threads 312 , 313 , 314 , and 315 are woven in the pattern similar to warp threads 310 and 311 . Therefore, each weft row and a subsequent weft row are tied to each other in the cross sectional plane.
[0047] FIG. 4 illustrates a single warp column, i.e., a single cross sectional plane along the warp threads of the 3D woven preform architecture 3D-O50. The 3D woven perform 3D-O50 is an orthogonal 3D weave with 50/50% warp/weft ratio. The 3D-O50 preform has very low crimp stuffer yarns (weft) and through-thickness weft binder yarns. This weave in this industry is sometimes referred to as a 3D non-crimp fabric due to the relatively straight stuffer yarns and weft yarns, especially when a smaller through-thickness binder yarn is used. Similar to the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A , in the 3D woven preform architecture 3D-O50 there are more cross sectional planes (not shown) that are only different by a shift in the pattern by a weft column.
[0048] As shown in FIG. 4 , the cross sectional plane includes warp threads 410 , 411 . . . 414 , and 415 . As shown in FIG. 4 , during the weaving of the 3D woven preform, the warp thread 410 is woven over the weft thread 450 , then over the weft thread 460 , then under the weft thread 475 , and finally under the weft thread 485 . The warp thread 411 is woven under the weft threads 450 , 460 , 470 , and 480 . The other warp threads 412 , 413 , 414 , and 415 are woven in the pattern similar to warp thread 411 . Therefore, all six weft rows in the cross sectional plane are tied to each other.
[0049] FIG. 5 illustrates a single warp column, i.e., a single cross sectional plane along the warp threads of the 3D woven preform architecture 3D-O70. The 3D woven perform 3D-O70 is an orthogonal 3D weave with 70/30% warp/weft ratio. The 3D-O70 preform has very low crimp weft stuffer yarns and through-thickness binder yarns. Similar to the 3D woven preform architecture 3D-P1-50 shown in FIG. 1A , in the 3D woven preform architecture 3D-O70 there are more cross sectional planes (not shown) that are only different by a shift in the pattern by a weft column.
[0050] As shown in FIG. 5 , the cross sectional plane includes warp threads 510 , 511 . . . 516 , and 517 . As shown in FIG. 5 , during the weaving of the 3D woven preform, the warp thread 510 is woven over the weft thread 550 , then over the weft thread 560 , then under the weft thread 575 , and finally under the weft thread 585 . The warp threads 511 and 512 are woven under the weft threads 550 , 560 , 570 , and 580 . The warp thread 513 is woven under the weft threads 551 , 561 , 571 , and 581 . The warp threads 514 and 515 are woven in the pattern similar to warp thread 513 , and the warp threads 516 and 517 are woven in the pattern similar to warp threads 511 and 512 . Therefore, all six weft rows in the cross sectional plane are tied to each other.
[0051] After the desired 3D woven preform structure has been formed, the structure may be impregnated with a matrix material to form a composite. The structure becomes encased in the matrix material and matrix material fills the interstitial areas between the constituent elements of the structure. The matrix material may be any of a wide variety of materials, such as epoxy, polyester, vinyl-ester, ceramic, carbon and/or other materials, which also exhibit desired physical, thermal, chemical, and/or other properties. The materials chosen for use as the matrix may or may not be the same as that of the structure and may or may not have comparable physical, chemical, thermal or other properties. Typically, however, they will not be of the same materials or have comparable physical, chemical thermal or other properties, because a common objective sought in using composites is to achieve a combination of characteristics in the finished product that is not attainable through the use of one constituent material alone. So combined, the structure and the matrix material may then be cured and stabilized in the same operation by thermosetting or other known methods, and then subjected to other operations toward producing the desired component. After being so cured, the then solidified masses of the matrix material are adhered to the structure. As a result, stress on the finished component, particularly via its matrix material acting as an adhesive between fibers, may be effectively transferred to and borne by the constituent material of the structure.
Comparative Test Results of Specific Energy Absorption (SEA) of Present Structure
[0052] The 3D woven preforms 3D-P1-50, 3D-P1-70, 3D-P2-50, 3D-O50, and 3D-O70 have improved properties that can lead to high specific energy absorption (SEA) that enables the manufacturing of 3D woven composite parts that can replace ones made from traditional materials such as laminated composites or high strength metals, at a lighter weight. In order to demonstrate this, an experimental study was conducted, where the SEA of various 2D laminated and 3D woven carbon-epoxy composites were measured and compared. Three different layups were considered for the 2D laminated composites with the aim of triggering three different energy absorption modes. For 3D woven composites, variations of two primary architectures were considered for a total of five different configurations.
[0053] FIG. 6 illustrates a corrugated shaped composite test specimen before (A), during (B), and after (C) testing. Since SEA is a combined material and structural property, test specimens with a corrugated geometry were selected based on published work. All specimens were crushed between flat platens under quasi-static and dynamic conditions, as shown in FIG. 6 . The same commercial grade standard modulus carbon fiber and automotive grade epoxy resin was used to manufacture all 2D and 3D composite specimens. Fiber volume fraction for all eight configurations was roughly 60% within manufacturing tolerances. Force-displacement curves measured during testing and specimen weights were used to calculate SEA values.
[0054] FIG. 7 illustrates a quasi-static SEA comparison of all eight configurations tested with 3D woven composites shown as A-E and 2D laminated composites as F-H. The results of the quasi-static testing showed that all but one 3D woven composite design performed better than all 2D laminated composites. The improvement over 2D-S for one 3D architecture family was 20% for 3D-P50-3v2 and 50% for 3D-O50. Under dynamic loading which better represents an actual crash situation in a vehicle, 3D woven composites performed better than 2D.
[0055] FIG. 8 illustrates a chart comparing rate dependent SEA values for four configurations. Medium (1.7 m/s) (A) and high-rate (6.4 m/s) (B) dynamic testing results showed the same trends with a roughly 33% drop in SEA for 2D-S and a 26% drop for 3D-O50 over quasi-static dynamic values (C).
[0056] FIG. 9 illustrates four variants of a possible automotive application for the development of a 3D woven composite longitudinal component. In FIG. 9 an automotive crash tube application is shown that provides different levels of structural support and integration, for example, (1) parasitic and only for frontal impact, (2) parasitic and for frontal and side impact, (3) combined crash-structural with driving loads, (4) integrated with other surrounding structures in the vehicle to reduce part count and cost.
[0057] It should be appreciated that the threads in the warp and weft directions may be of different material and/or sizes. The material of the threads, yarns, or fibers is not limited. While carbon fiber is described, the threads, yarns or fibers of the invention is applicable to practically any other fiber type, such as for example, glass, ceramic, aramid, polyethylene, polypropylene, stretch broken fibers such as stretch broken carbon fibers (SBCF) or other materials that can be stretch broken, or combinations of materials thereof, or any suitable material.
[0058] It should be appreciated that, although FIGS. 1A-5 describes several weaving patterns as examples, the present invention is, however, not limited to the described weaving patterns. Other embodiments are within the scope of the following claims.
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Described is a three-dimensional (3D) woven composites with high specific energy absorption (SEA) that significantly outperforms traditional two dimensional (2D) woven laminated composites of substantially the same weight.
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This application claims the benefit of Belgian Patent Application No. 2006/0032, filed Jan. 13, 2006, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting colour changes in a card design of the pattern of a fabric which might lead to mixed contours in the fabric, by means of a computer comprising central processing means, bus means, detecting means, data entering means, memory means and displaying means, the data of the card design of the pattern of the fabric being entered through data entering means and a processing programme applying correction lift plans to colour changes in a manner known already.
With face-to-face pile weaving in several colours, each warp system in the fabric will comprise all the colours of the pile warp yarns contained in the fabric. When a pile warp yarn is forming a pile, it will move between the upper and the lower fabric and will be interlaced alternately around a weft in each of the said fabrics. When the pile warp yarn is not forming a pile (dead pile), then it will be interlaced in the backing fabric of one of the two fabrics, the pile warp yarns being distributed among the upper and the lower fabric to be interlaced as a dead pile.
In order to obtain an optimal supply of pile warp yarns in the fabric, an exact formation of the shed and a clear view for the workmen replacing and supplying the bobbins of pile warp yarns in the weaving creel, in the weaving creel containing the bobbins of pile warp yarns and from where the pile warp yarns are supplied to the weaving machine, the pile warp yarns being interlaced in the upper fabric are provided at the top of the weaving creel and the pile warp yarns to be interlaced in the lower fabric are provided at the bottom of the weaving creel.
It is known that in pile fabrics, in certain cases, mixed contours or double acting pile warp yarns might occur at a colour change (this being a change of a pile warp yarn forming a pile where a pile warp yarn is no longer forming a pile and is interlaced as a dead pile in the fabric to which it belongs, whereas another pile warp yarn, from its interlaced situation as a dead pile is starting to form a pile in the fabric to which it belongs).
The occurrence of mixed contours means that two tufts of a different pile frame or of a different colour are crossing one another in the face-to-face fabric between two successive wefts in a fabric. Because no weft is separating the two tufts, the two tufts of a different colour have a strong tendency to take up a wrong position with respect to one another (which means that they will not rest against the adjacent tufts of the same colour, but will be situated between the tufts of a different colour) and this will produce a blurred pattern of the fabric.
A double acting pile warp yarn occurring, means that, between two successive wefts in a fabric, there will be found two tufts of a different pile frame or of a different colour running next to one another without crossing one another. In principle, such tufts situated next to one another are taking up a right position however with respect to the formation of the colour, but this position is not very well secured, due to which both tufts may easily change positions which, in turn, will cause the pattern of the fabric to become blurred.
These double acting pile warp yarns will likewise cause the fabric to become locally more closely woven, as locally, the number of tufts will be double the normal number.
Mixed contours occur depending on:
the weave structure (single, double, triple gripper weave structures in combination with the type of weave); from which fabric the pile warp yarn interlaced starting to form a pile is originating; in which fabric the pile warp yarn, no longer forming a pile, will be interlaced; in other words on the position of the pile warp yarns in the weaving creel, since the position of the pile warp yarns in the weaving creel is related to the fabric in which the pile warp yarn will be interlaced as a dead pile.
In the table below, some examples are shown of situations in which mixed contours (MC) or double acting pile warp yarns (DW) are occurring. The designation (0) means that neither mixed contours nor double acting pile warp yarns are occurring. When designating the colour changes (BT-BT; BT-OT; OT-OT and OT-OT), the first designation is designating the fabric in which the pile warp yarn stops to form a pile is interlaced as a dead pile and the second designation is designating the fabric from which the pile warp yarn starting to form the pile is originating. (BT stands for upper fabric (upper carpet), OT stands for lower fabric (lower carpet).
Weave structure
BT—BT
BT-OT
OT—OT
OT-BT
single gripper 1/1 V
0
0
0
0
double gripper ½ V
MC
0
MC
MC
double gripper 1/1 V
0
DW
0
0
three gripper ⅔ V
0
DW
0
0
three gripper 2/2 V
0
DW
0
0
three gripper 1 + ⅔ V
0
DW
0
0
In the following part of this patent application mention will only be made of mixed contours where, each time, both mixed contours and double acting pile warp yarns are meant.
Such mixed contour effects may be avoided by respecting a number of designing rules. Thus, a designing rule for ½V weaves is stating that in the card design, at a colour change in which two colours are involved, at least one of the two colours should be present along two lines of the same colour (the same pile frame) in the warp direction. In this manner it will be possible to use the method described in the European patent publication EP 927782 and in which of at least one of the pile warp yarns involved in the colour change, one double lift plan before the pile change or one double lift plan after the pile change is replaced by correction lift plans. For in this correction lift plan one colour point is omitted. When this occurs so that the colour point that is omitted is from the colour of which two lines, and therefore two points, are situated one after the other in the warp direction, still one colour point will remain after having applied the correction lift plan.
In practice, such correction lift plans may be applied automatically in the processing software converting the card design (pattern) into a file serving as an input to activate the Jacquard machine.
However, in order to apply this method, as designated, a number of designing rules have to be observed when producing the card design (the pattern). The correction lift plan is only applicable to produce the effect expected when, during two successive lift plans (successive in the warp direction) the pile is formed by the same pile warp yarn. In practice we find that these designing rules are not always applied, so that even when the correction lift plans are automatically applied by the processing software converting the card design into a file serving as an input to activate the Jacquard machine, mixed contours are still occurring.
The designer of the card design does not sufficiently realize when mixed contours are occurring and what is causing them, because possibly he is not sufficiently aware of the rules for designing and the effects caused by not applying them, but mostly because it is not clear to him why these effects are occurring in one situation and not in another situation (more especially, because the final position of pile warp yarns in the weaving creel as well as the weave structure are not known to him).
The persons in the manufacturing department who are carrying out the processing, selecting the texture of the fabric and selecting the Jacquard machine with the accessory weaving creel are unable to take action to adapt the card design where necessary or dare to interfere only slightly, so that mixed contours will continue to occur.
In many cases, mixed contours are only eliminated, when the quality of the pattern of the fabric produced will be affected too strongly. In practice, in many cases the assistance of the supplier of the Jacquard machine or of the processing software will be requested in order to remedy the effects.
This means, however, that products of an inferior quality with a blurred pattern are produced and in some cases the product even has to be rejected, before corrections are finally made. Furthermore, these interventions by the suppliers will cause a waste of time and additional costs.
SUMMARY OF THE INVENTION
The purpose of the present invention is to define a method offering assistance during the manufacturing process of the pile fabrics in accordance with card designs produced before or during a file being processed to activate the Jacquard machine in order to avoid mixed contours.
The purpose of the invention is attained by providing a method for detecting colour changes which might be the cause of mixed contours in a card design of the pattern of a fabric, by means of a computer comprising central processing means, bus means, detecting means, data entering means, memory means and display image means, wherein the data of the card design of the pattern of the fabric being entered by the data entering means and a processing programme applying correction lift plans to colour changes in a manner known already, the colour changes in the card design being detected by means of the detecting means based on the data entered through the data entering means and colour changes being designated by means of the display image means where a mixed contour is occurring in the fabric, impossible to be avoided by correction lift plans.
Preferably, the data entered are the card design of the pattern of the fabric, the selected weave structure and the position of the pile frames in the weaving creel of the Jacquard weaving machine on which the fabric will be woven.
The data of the card design of the pattern of the fabric, the weave structure and the position of the creel may be contained in the computer or they may be entered by means of any data entering means known, such as manual input, loading through a network or other possible connections from the machine, from a CAD-system, from another computer, from a data carrier (diskette, CD-rom, USB-stick, etc).
Furthermore, the method according to the invention consists in screening the card design by means of a computer (programme) in combination with the data about the actual position of the pile frames in the creel of the Jacquard weaving machine on which the fabric will be woven and in combination with the data about the weave structure which will be applied, for a correct application of the designing rules which should enable correction lift plans to be applied where a mixed contour will occur in the manner known by the state-of-the-art, examples of which are described in EP 0927782, before converting the card design of the pattern of the fabric into a file to activate the Jacquard machine on which the fabric containing the said pattern will be woven.
As an output by means of display image means, the method produces designations in the card design where a mixed contour is occurring impossible to be avoided by means of a correction lift plan. This may be done, for instance, by causing pixels to become fluorescent or to start flashing in the card design, by marking the area by means of a line or a circle or by any other means of display.
This should yet enable the user, before converting the card design into a file to activate the Jacquard machine, to adapt the card design to the designing rules, so that correction lift plans may still be used in order to avoid any mixed contours. This method has the advantage that, before the fabric is actually woven, it will be clearly visible whether mixed contours will occur, and that even before the weaving process has started, it will be possible to take action in order to avoid these mixed contours by adapting the card design. Hence, producing fabrics of an inferior quality or rejection will be avoided.
Furthermore, this method has the advantage that only those mixed contours are compensated typical of the actual position of the pile frames in the weaving creel in combination with the weave structure actually applied.
In a preferred method according to the invention, the computer may be set up in such a manner that only colour changes liable to be the cause of a mixed contour and for which a correction by means of a correction lift plan is not possible, a certain minimum number of which are extending next to one another, are designated. In practice, one single isolated mixed contour in a fabric will not always be noticed and moreover, certain drawings (patterns, designs) are aiming indeed at the fact that different pile warp yarns will form a cloud of points of different colours, the mixed contours intensifying the effect desired. The minimum number of colour changes situated next to one another showing mixed contours impossible to correct by means of a correction lift plan and where it is decided to maintain the mixed contour for smaller numbers of colour changes situated next to one another, may be adjusted by the user of the computer programme carrying out the method.
In its simplest form, colour changes, lying next to one another in the weft direction, will be considered in this case. Since the error created by mixed contours is more pronounced in the warp direction and the warp direction is at right angles to the weft direction, the colour changes in the card design, which in the weft direction are situated next to one another and to which it is impossible to apply any correction lift plans in order to avoid mixed contours, will be found to be most distinctive as being a deviation with respect to the pattern desired of the woven product. When the user is adapting these colour changes in the card design in accordance with the designing rules, this will be the most efficient contribution to an improvement of the quality.
In a more perfect method the minimum number of colour changes situated next to one another liable to cause mixed contours, not possible to be avoided by means of correction lift plans, may be situated in a straight line in any direction and in yet another preferred method, even connected may show any line, the straight or any line, each time having to comprise a minimum number of points, adjusted by the user to be designated as a point or an area in which mixed contours will occur after having applied the processing programme in order to avoid mixed contours by means of correction lift plans. Determining these straight lines running in any direction and lines having any possible shape may occur, for instance, by vectorizing the card design.
It may be obvious that, when the user is adjusting to one the number of points situated next to one another showing mixed contours without possibility of compensation by means of correction lift plans, the computer programme carrying out the method according to the invention, will inform the user of all points in the fabric where a mixed contour will occur.
In a further preferred method according to the invention, the computer programme does not only designate the colour changes or the set of colour changes where mixed contours will occur but, as part of the designation, the computer programme will designate, per colour change or set of colour changes, where mixed contours will occur, one or several suggestions in order to correct the card design to avoid the mixed contours. Then, the user has the possibility to select one of the suggestions made to be validated or to select himself another adaptation of the card design or to maintain the actual version of the card design.
In yet a further preferred method, for part of or all the colour changes detected, the computer programme will carry out automatic corrections of the card design in order to avoid an occurrence of mixed contours.
To select the suggestions for adapting the card design in order to be able to avoid mixed contours by applying correction lift plans, the computer programme has to form a picture of the figure elements in the card design to which the points of the card design belong which are situated in the warp direction on both sides of the colour change, where it is impossible to remove a mixed contour by means of correction lift plans. In order to locate these figure elements in the card design, preferably part of the figure or the entire figure is vectorized.
The card design is a grid design, defining a grid of points, the axes of the grid corresponding to the warp and weft directions. In the grid, a colour is assigned to each point. By locating points in the grid design situated near the edge of colour changes and by keeping in mind the direction between successive points, part of the grid design is vectorized so that it will be possible to recognize the figures in the card design.
This vectorized information may be noted down in a separate layer of the design.
It is also possible to vectorize the entire card design.
In this case, in this vectorized information, the selection is made which form of the pattern is most suitable to be adapted in order to avoid mixed contours in accordance with a decision logic laid down in a computer programme and the adaptation of the form of the pattern will be carried out in the vectorized information. Then the programme will convert the vectorized information into grid information. The method will be able either to confirm this adaptation immediately or to ask the user for approval still, before carrying out the adaptation. In case of the user's approval, the process will be continued using the adapted grid design in order to eliminate any further mixed contours which are impossible to avoid by means of correction lift plans, by adapting the card design. When the complete card design of the pattern of the fabric, in accordance with the invention has been passed through, the processing programme is started, the adapted card design being converted into a file suitable to activate the Jacquard machine.
Therefore, by means of the vectorized information (position and direction), the form of the pattern may be deducted from the elements of the pattern and the necessary information is available to adapt the entire form of the pattern by means of the computer programme in order to avoid mixed contours, allowing the form of the pattern to maintain certain characteristics because of the adaptation (for instance, a circular form may be adapted to a new circular form with a corrected radius). Hereby the information about the direction is important when at a certain point or in a certain area of the circular form a number of points have to be added in order to avoid a mixed contour in the card design by applying correction lift plans to adapt the complete form of the pattern in order to maintain essential characteristics of the form of the pattern (for instance, the circular form, . . . ).
Other specific and advantageous methods for detecting colour changes according to this invention are described in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGS. 1 , 2 , 3 and 4 represent the method and steps according to the invention in block diagrams
FIG. 5 shows mixed contours and corrected color changes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As represented in FIG. 1 , in step S 1 , the data entered are the card design of the pattern of the fabric, the texture of fabric selected and the position of the pile frames in the creel of the Jacquard weaving machine on which the fabric will be woven. In step S 2 , the entered data are scanned for colour changes causing mixed contours impossible to avoid by means of a correction lift plan. The method produces designations (S 103 ) in the card design where a mixed contour is occurring impossible to be avoided by means of correction lift plans. Subsequently, the card design will be adapted (S 104 ) in order to avoid mixed contours by creating possibility to apply correction lift plans. As long as the card design is not completely passed through, the loop P 101 is completed.
FIG. 2 represents also S 1 and S 2 . According to FIG. 2 , the method designates and displays colour changes or areas with colour changes where occurring of mixed contours are impossible to avoid by means of correction lift plans (S 203 ), and also designates and displays one or several suggestions (S 204 ) in order to correct the card design to avoid the mixed contours. Then, the user has the possibility to select one of the suggestions to be validated or to select himself another adaptation of the card design or to maintain the actual version of the card design (S 205 ). As long as the card design is not completely passed through, the loop P 201 is completed.
FIG. 3 represents also S 1 and S 2 . According to FIG. 3 , the method automatically adapts the card design due to which mixed contours may be avoided by applying correction lift plans.
As represented in FIG. 4 the card design is a grid design, defining a grid of points (S 401 ), the axes of the grid corresponding to the warp and weft directions. In the grid, a colour is assigned to each point. By locating points in the grid design situated near the edge of colour changes and by keeping in mind the direction between successive points, part of the grid design is vectorized (as is expressed in step S 402 ) so that it will be possible to recognize the figures in the card design. In step S 403 , card design in point grid is scanned for colour changes with mixed contours impossible to be compensated by correction lift plans. When a colour change with mixed contour impossible to compensate by correction lift plan is detected a step 404 starts, in which the card design in vector grid is scanned from the detected point of problematic colour change out to detect the figure line in the card design to which the point of problematic colour change belongs. Step 405 determining, using the information on the figure lines detected in step 404 , adaptation patterns in card design in vector grid as suggestion(s) for adapting card design to avoid mixed contours impossible to avoid by means of correction lift plans. The method will be able either to confirm this adaptation immediately or to ask the user for approval still, before carrying out the adaptation. In case of the user's approval, the process will be continued (step 406 ) using the adapted grid design in order to eliminate any further mixed contours which are impossible to avoid by means of correction lift plans, by adapting the card design. After converting this modification from card design in vector grid into card design in point grid (step 407 ), step 403 to S 407 is repeated until the complete card design of the pattern of the fabric, in accordance with the invention has been passed through. After this the processing programme is started, the adapted card design being converted into a file suitable to activate the Jacquard machine.
During processing (converting the card design into a file to activate the Jacquard controller) correction lift plans are applied wherever possible, as represented in FIG. 5 . Here, in a ½V weave structure, in a double rapier technique a pile warp change (colour change) is represented of a first pile-forming pile warp yarn being interlaced as a dead pile in the lower fabric towards a second pile-forming pile warp yarn being interlaced in the upper fabric as a dead pile.
In the representation “before” a correction lift plan is applied, it will be noticed that a mixed contour will occur.
“After” the correction lift plan has been applied, the mixed contour has been avoided, but an entire pile tuft (two tufts) of the first pile warp yarn has been lost. In the lower fabric of the same part of the pattern, however, the same amount of pile tufts and tufts are maintained.
In the lower part of the pattern, in the lower fabric an entire pile tuft (two tufts) of the second pile warp yarn has been lost, whereas in the upper fabric of the same part of the pattern all pile tufts and tufts remain.
This means, that in case the correction lift plans would have been applied to a part of the card design in which, in the warp direction, two or several single colour lines are occurring successively (one line of a certain colour followed by a line of a different colour, possibly again followed by a line of a different colour) here at least one colour line would disappear in one of the fabrics, which is unacceptable with respect to the design aimed at during the weaving process.
Therefore, normally the processing programme of the processing software will not apply these correction lift plans in cases in which a certain colour should disappear in one of the two fabrics after the correction lift plans having been applied, so that a mixed contour will definitely not occur during the weaving process.
It is indeed possible to avoid such an imperfection by adapting the card design, so that, at each colour change, at least one of the colours involved in the colour change will be present across two colour lines. Then the processing programme within the processing software will select these correction lift plans, the pile tuft having been lost, being a pile tuft of a colour of which there are two colour lines in the card design, so that in both fabrics at least one of both colour lines will be maintained as a pile tuft.
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A computer reviews card designs for color changes in a fabric pattern that might cause mixed contours in the fabric woven by a Jacquard design. The computer displays problem positions of the card designs that cannot be corrected by correction lift plans and suggests changes to the card designs. When permitted the computer automatically changes the card designs to avoid mixed contours.
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RELATED APPLICATION
[0001] The present application is a continuation of application Ser. No. 09,165,142 filed Oct. 1, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates to the internet and more particularly to browsers that are used to display web pages obtained from the internet.
BACKGROUND OF THE INVENTION
[0003] There are numerous commercially available programs called “browsers” that facilitate accessing and displaying data. The two leading commercially available browsers are the “Netscape Communicator” which is distributed by Netscape Corporation of Mountain View, Calif. and the “Internet Explorer” browser that is distributed by Microsoft corporation of Redmond, Wash.
[0004] Browsers allow one to utilize the internet to access web pages located at remote sites. A browser displays web pages in a window on a display device. The web pages that are displayed can contain both text and images.
[0005] Technology called stegangraphy had been developed which allows one to store digital data in an image. Such data is frequently termed a “digital watermark”. The digital data is not visible when an image containing such data is displayed with a conventional browser; however, the image can be passed through a special program which can detect and read the hidden data. Systems for storing digital data in images and for then reading such data from the images are for example shown in U.S. Pat. No. 5,636,292 and in U.S. Pat. No. 5,748,783. Such technology is also discussed in the “Communications of the ACM” published July 1998 Vol. 41. No. 7 pages 31 to 77.
[0006] The present invention provides programs which works with a browser to provide functions that are not performed by prior programs. A typical web page displayed by a browser contains several images. With a conventional browser, a user can not visually determine if any of the images displayed on a web page contain a watermark.
SUMMARY OF THE INVENTION
[0007] The present invention is an adjunct to a convention browser which displays web pages that contain images. With the present invention a special visual indicia is placed on images which contain a digital watermark so that a user can know that the image contains hidden watermark data. By clicking on the indicia which is placed on the image, the user will be linked to the web page identified by the watermark data hidden in the image. Such a link will be established without the web page designer having to include a tag in the web page which displays the original image. The present invention also opens a separate widow which contains a thumbnail of each image in a web page. If a user right clicks on one of the thumbnails in this window the image will be added to a list of images in a special image bookmark file. When a user opens the bookmark web page, thumbnails of all the stored images in the bookmark file are displayed. A user can recall the web page which originally contained the image by clicking on the thumbnail.
BRIEF DESCRIPTION OF THE FIGURES
[0008] [0008]FIG. 1 is a block diagram of a prior art browser.
[0009] [0009]FIG. 2 is a block diagram of an embodiment of the present invention
[0010] [0010]FIG. 3 is flow diagram of the operation of the preferred embodiment
[0011] [0011]FIG. 4 is a diagram of a display screen of the preferred embodiment.
[0012] [0012]FIG. 5 is a diagram of a display screen showing bookmarks.
[0013] [0013]FIG. 6 is a flow diagram of the operation of the bookmark program
DESCRIPTION OF PREFERRED EMBODIMENT
[0014] The preferred embodiment of the invention is implemented utilizing what is known in the art as “helper application” for the Internet Explorer 4.0 browser. The Internet Explorer 4.0 browser is commercially distributed by Microsoft Corporation. FIG. 1 is a block diagram of the commercially available Internet Explorer 4.0 browser 10 . Browser 10 provides a mechanism for receiving and displaying data (called Web Pages) received from the World Wide Web (which is often referred to as W W W).
[0015] The preferred embodiment of the invention described herein is designed to operate based on watermarks which have a particular format designed by Digimarc Corporation. Many of the commercially available programs which can insert watermarks in images and which can detect watermarks in images utilize this watermark format. For example, the Digimarc format is used by the following commercially available programs: “Adobe PhotoShop” Versions 4.0 and 5.0 and “Adobe ImageReady” Version 1.0 which are marketed by Adobe Corporation, “CorelDRAW” Versions 7 and 8, and “Corel PHOTO-PAINT” Versions 7 and 8 which are marketed by Corel Corporation, and Micrografx Webtricity” Versions 1 and 2, “Micrografx Graphics Suite 2 ”, and “Micrografx Picture Publisher” Versions 7 and 8 which are marketed by Micrografx Corporation.
[0016] The base program in the Internet Explorer 4.0 browser, that is, the program which begins the operation of the browser 10 is IEXPLORE.EXE 11 which is shown in FIG. 1. Program 11 calls the web browser control dynamic link library SHDOCVW.DLL 12 .
[0017] As stated in the documentation of the Internet Explorer provided by Microsoft SHDOCVW.DLL 12 “supplies the functionality associated with navigation, in-place linking, favorites and PICS support.” SHDOCVW.DLL 12 in turn hosts or calls the MSHTML.DLL 13 dynamic link library. MSHTML.DLL “performs the HTML parsing and rendering” and also “exposes the HTML document through the Dynamic HTML Object Model” 14 . The HTML Object Model 14 hosts the Active X Control 14 A, the Active X Engine 14 B, the JAVA VM 14 C and the Plug In Applet 14 D. The various components in browser 10 store and retrieve information from URL Cache 15 . The operation and function of the various components of the Internet Explorer browser are described in the publicly available literature (and on the web site) provided by Microsoft Corporation.
[0018] The preferred embodiment of the invention adds a browser helper object 21 and two other programs 22 and 23 as shown in FIG. 2. Program 22 is a conventional program designed to detect a watermark in an image. One example of such a program is shown in U.S. Pat. No. 5,636,292. Another program for detecting watermarks is shown in U.S. Pat. No. 5,689,587. The browser helper object 21 interfaces with the dynamic link library MSHTML.DLL 13 and with the URL cache 15 .
[0019] [0019]FIG. 4 illustrates an example of a web page being displayed in a window 40 on display screen 41 by browser 10 . The example shown in FIG. 4 has four images designated image 1 , image 2 , image 3 and image 4 . It should understood that the number of images and the placement of the images varies in each web page displayed and it is determined by the person who creates a web page. Furthermore, text may be interspersed with the images. The example shown in FIG. 4 is a simple example of a web page which is herein used to illustrate the operation of the present invention.
[0020] The present invention detects which images on a web page contain a watermark. The images which contain watermarks are flagged or noted by means of an indicia which is added to the lower right hand corner of any images that contain watermarks. In the example shown in FIG. 4, image 3 contains a watermark and thus indicia 46 appears on the lower right hand corner of the image. Indicia 46 could for example be a logo which identifies a particular company or it could be any other easily identified mark or symbol. It could be as simple as the letters WM or it could be a small multicolored image. The indicia which is displayed is stored in GIF file (Graphic Interchange Format file) and referenced by HTML code (HyperText Markup Language code) which causes the indicia to be displayed.
[0021] The data in the watermarks (which have the previously defined format) includes a particular HTML address. With the present invention if a user clicks on the indicia 46 , a link is created and executed to a particular web page on a particular server herein identified as “www.digimarc.com/cgi-bin”.
[0022] The program 20 also opens a separate window 42 and it places a thumbnail (i.e. a reduced version) of each image in window 42 . In the example shown in FIG. 4, thumbnails 42 A, 42 B, 42 C and 42 D are small versions of images 1 to 4 respectfully.
[0023] Program 20 also creates an image or “button” 45 which contains the symbol BM. If a user right clicks on one of the images in window 42 , that image is saved as a bookmark. If at a later time a user clicks on the BM image 45 , the system displays a list of the previously saved images 53 a to 53 h as shown in FIG. 5. When a user clicks on one of the displayed images 53 a to 53 h , a link is executed to the page from which the image originated, and thus that page is again displayed by the browser 10 .
[0024] [0024]FIG. 3 is a block flow diagram of the operation of the browser helper object 21 and program 22 . Block 31 indicates that initially the browser 10 receives data and it renders images in window 40 on the screen 41 as is normal for the operation of the browser 10 . Block 32 indicates that when the download operation is complete, MSHTML.DLL 13 sends a “Download complete event” and a “Document Object” to Browser helper Object 21 . The Document Object includes the URL addresses of each of the images in the page that is displayed. The characteristics of a Download Complete Event and a Document Object is explained in the documentation provided by Microsoft Corporation. Block 34 indicates that Browser Helper 21 sends a request to MSHTML for the address in cache 15 of one of the URL addresses which it previously received. The documentation supplied by Microsoft corporation explains how the above operations are performed.
[0025] Block 35 indicates that when browser helper 21 receives a Download Compete Event from MSHTML.DLL 13 , the browser helper 21 queries the “Document Object”. The images which are in the page being displayed are available to the browser helper 21 in the current “Document”. The browser helper 21 retrieves the image data from the URL cache 15 and processes it as follows: The image is passed through watermark detector program 22 to determine if the image contains a watermark and bookmark program 23 places a thumbnail of the image in window 32 .
[0026] As indicated by block 38 , if no watermark is detected (and if this is not the last image which appears in the window being displayed) the program flow returns to block 34 and the process repeats for another image. If the image being processed is the last image in a window the process stops and does not begin again until browser helper 21 receives another “download Compete Event” signal.
[0027] If a watermark is detected by watermark detector 22 , the process proceeds to block 39 . As indicated by block 39 , in this event helper Program 21 calculates the position of the lower right hand corner of the image and “inserts” a HREF and an IMG tag to the current document object of MSHTML.DLL. In response to the HREF and IMG tag, MSHTML.DLL will display an indicia such as indicia 46 in the lower right hand corner of the image with the watermark. The browser helper can calculate the lower right hand corner of the image where the indicia 46 is to be inserted from the location data of the image. The location where the image is to be inserted is given in the HREF command.
[0028] The following is an example of and HREF and IMG tags:
[0029] <a href=“http://www.digimarc.com/cgi-bin/c1.p1? 4 + 404407 + 0 . 0 .+ 1 .”
[0030] <IMG SRC=‘ind46.gif’ STYLE=“position:absolute;left:125;top:200;filter;alpha(opacity)”></a>
[0031] where: ind46.gif is a GIF image of the indicia 46 .
[0032] The general format of such HREF and IMG tags is entirely conventional and well known. Likewise the technique for “inserting” a HREF and an IMG tag to the current document object of MSHTML.DLL is well known and conventional.
[0033] When watermark detector 22 determines that a particular image contains a watermark, the browser helper 21 inserts tags such as the above to the MSHTML.DLL 13 which then superimposes indicia 46 over the image being displayed by the browser 10 .
[0034] An Active X browser control program publicly available from Microsoft Corporation is used to display the thumbnails in widow 42 as shown in FIG. 4. The Active X browser control program is also used to display the image bookmarks as shown in FIG. 5.
[0035] A specific example of image HTML used to display thumbnails in window 42 using an Active X browser control is given below.
<table width = 72> <tr><a href=‘http://safari.altavista.digital.com/cgi-bin/VP?START=1’ title=‘http://safari.altavista.digital.com/cgi-bin/VP?START=1’><font size=1 color=‘blue’ face=‘Verdana,Arial,Helvetica’> <P onmouseover=“this.style.color = ‘red’”; onmouseout=“this.style.color = ‘blue’”;>Corbis Picture Experience - AltaVista - BETA TEST<P> </font></a></tr> </table> <table cellspacing=‘1’ cellpadding=‘1’, border=‘0’ width=‘72’> <tr> <td rowspan=‘2’><a <td rowspan=‘2’><a <td rowspan=‘2’><a
[0036] The above example includes three images. The brackets at the right hand side of the above code indicate the sections of code which display each image. When in use, the number of images equals the number of images on a particular web page which is being displayed.
[0037] A block diagram of the program used to add images to the list of image bookmarks is shown in FIG. 6. With reference to FIG. 4, if a user would like to add one of the images 1 to 4 to a list of images that the user has bookmarked, the user would right clicks on the thumbnail of that image which shown in widow 42 (block 61 ). As a result of the right click, a drop down window (not specifically shown) will appear asking for the name the user wants to associate with the image (block 62 ). It is noted that the use of drop down widows to add information is conventional and well known. When the drop down window appears, the user enters a name and the image is added to the list of bookmarks with the name entered.
[0038] Similar HTML code to that given above is used with the Active X Browser control to display bookmarks as shown in FIG. 5. The following is an example of HTML code which displays bookmarks as shown in in FIG. 5. Such HTML is conventional and many alternative sequences of HTML can be used to generate a similar page of images.
<html> <head> <title>Digimarc Watermark Explorer Bookmark</title> <body vlink=‘blue' link=‘blue’> <table width= 100 align=‘center’> <tr> <td><a href=‘http://www.cnn.com/’ name=‘Bookmark_C’><font size=1 color=‘blue’ face=‘Verdana,Arial,Helvetica’><U onmouseover=“this.style.color= ‘red’”; onmouseout=“this.style.color = ‘blue’”; >CNN lnteractive</U> </font></a></td></tr> <tr> {close oversize bracket} <td width=‘100’ align=‘center’> <a href=‘http://www.cnn.com/’><img src=“http://www.cnn.com/images/1998/05/homepage/cnnin.logo.gif” alt=‘http://www.cnn.com/’border=‘0’ height=‘52’ width=‘70’></a> </td> </tr> </table> <table width= 100 align=‘center’> <tr> <td><a href=” name=‘Bookmark_M’><font size=1 color=‘blue’ face=‘Verdana,Arial, Helvetica’><U onmouseover=“this.style.color = ‘red’”; onmouseout=“this.style.color = ‘blue’”; >Microsoft Investor</U> </font></a></td></tr> <tr> <td width=‘100’ align=‘center’> <a href=”><img src=“http://investor.msn.com/common/images/invlogo.gif” alt=“ border=‘0’ height=‘48’ width=‘70’></a> </td> </tr> </table> <table width= 100 align=‘center’> <tr> <td><a href=“ name=‘Bookmark_P’><font size=1 color=‘blue’ face=‘Verdana,Arial,Helvetica’><U onmouseover=“this.style.color = ‘red’”; onmouseout=“this.style.color = ‘blue’”; >PC World</U> </font></a></td></tr> <tr> {close oversize bracket} <td width=‘100’ align=‘center’> <a href”><img src=“http://www.idg.net/channels/ie4/english/images/idg_logo.gif” alt” border=‘0’ height=‘52’ width=‘70’></a> </td> </tr> </table> </body> </html>
[0039] The brackets to the right of the above HTML show the sections of HTML used to display one bookmark. Naturally it should be understood that the above is merely an example of one particular set of HTML that can be used to display a list of bookmarks. Various other sequences of code can be used to obtain similar functions. HTML code such as that shown above is conventional and widely used.
[0040] Another feature that can be added to the preferred embodiment is that window 42 can be used to display a visual history of the pages that have been viewed. That is one could include in window 42 a button that would allow one to scroll back through the thumbnails previously displayed in the window.
[0041] While the invention has been showed with respect to a preferred embodiment thereof, it should be understood that various changes and modifications can be made without departing from the spirit of the invention. The scope of applicant's invention is defined by the following claims.
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Web pages which contain images are displayed by a browser. A special visual indicia is placed on any the images which contain a digital watermark so that a user can know that the image contains hidden watermark data. By clicking on the indicia which is placed on the image, the user will be linked to the web page identified by the watermark data hidden in the image. Such a link will be established without the web page designer having to include a tag in the web pages design which displayed the original image. The present invention also opens a separate widow which contains a thumbnail of each image in a web page. If a user right clicks on one of the thumbnails in this window the image will be added to a list of images in a special image bookmark file. When a user opens the bookmark web page, thumbnails of all the stored images in the bookmark file are displayed. A user can recall the web page which originally contained the image by clicking on the thumbnail.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/047,422, filed Jan. 14, 2002; which application is incorporated herein by reference.
TECHNICAL FIELD
The principles disclosed relate to an enhanced sonde housing and method of manufacture. More particularly, this disclosure concerns a sonde housing constructed for use in a variety of applications and method of making such housing.
BACKGROUND
Horizontal directional drilling is a process commonly utilized to create boreholes for the installation of utilities underground. The process involves a drilling machine, a drill string and a drill head. The drill string is typically composed of individual sections of hollow drill rod, and is attached above ground between the drilling machine and the drill head. The drilling machine is typically capable of rotating and longitudinally propelling and thrusting the drill string, while simultaneously pumping a fluid through the drill string. The drill head is typically composed of an adapter assembly and a drill bit. There are many types of adapter assemblies, including static and dynamic, each typically connecting on one end to the drill string, and on the other end to the drill bit. There are a variety of drill bits, each designed to be used in conjunction with a specific type of adapter.
The process starts with installing the drill head onto a single drill rod above ground. The drill rod is then connected, at the opposite end, to a drilling machine. The drilling machine then rotates and pushes the drill rod and drill head into the ground. At the same time, a fluid is pumped through the drill rod and typically directed to the cutting surface of the drill bit to assist in cutting the ground material.
The pumped fluid has a variety of purposes. One primary purpose relates to removal of material to create the borehole. In this application, fluid transports cuttings created by the drill bit back along the bored hole and out to the ground surface. In most setups, a particular drill bit is configured to cut a hole larger than the drill rod diameter by disturbing the soil formation as it is rotated. Examples of such bits can be found in U.S. Pat. Nos. 5,799,740 and 5,899,283. At the same time, a water-based fluid is pumped through the drill string and through the bit to thoroughly mix with the disturbed soil, creating a slurry. The slurry then follows the path of least resistance, which is typically back along the drill string, and exits at the point the drill string enters the ground. In this application the adapter assembly is static, simply adapting from the drill rod threaded connection, which is smaller diameter, to the drill bit, which is larger in diameter to cut the larger hole required for the proper transfer of cuttings.
In some other applications there is no requirement to transport the cuttings and the ground is simply compacted, forming a borehole without any material removal. Impact or hammering load on the drill bit increases the productivity of drilling. For this type of application, the adapter assembly includes a dynamic component, typically a pneumatic hammer, in addition to a static adapting element. (An example disclosed in U.S. Pat. No. 4,858,704.) The fluid being pumped in the drill string is compressed air that transfers power to actuate the pneumatic hammer. The path of fluid flow includes the drill string, the static component of the adapter assembly, and the hammer.
In yet other applications, typically highly compressed soils and or rock, a similar setup utilizing a down hole hammer can be used in conjunction with a different drill bit to create cuttings for transport. The hammers can be pneumatic hammers or water hammers. The drill bits are designed primarily to fracture the soil or rock formation by the impact loading received from the hammer. Once the formation is fractured, the cuttings need to be transported away from the cutting face.
Transportation of the cuttings is aided by rotation of the drill bit and drill string, along with the resulting flow of the fluid. The fluid is typically air or a mixture of air and a water based fluid or other suspension material which functions to aid the air's ability to transport the cuttings. In this type of application, the fluid is utilized to transfer power to actuate a hammer to transport cuttings. The path of fluid flow includes the drill string, adapter assembly and drill bit.
In still another arrangement involving cutting highly compressed soils or rock, the drill bit is adapted to rotate. One such design includes the use of a mud motor capable of converting fluid power (from the pumped fluid) into rotational power to rotate the drill bit. In this type of application, the adapter assembly includes a dynamic component, the mud motor, along with the previously described static element. The fluid is typically water based. The path of fluid flow includes the drill string, the adapter assembly and the drill bit.
In all these applications, the transfer of fluid assists in the efficient functioning of the drill bit and/or transportation of the cuttings; relatively large flow rates may be required. The path of fluid flow, in all cases, is through the adapter. Thus a key characteristic of the adapter is fluid transfer capability.
Another key aspect of horizontal directional drilling is the detection of location and position of the drill head. This information is necessary to properly control the drilling process so that the bored hole is properly positioned. This is typically accomplished by installing tracking electronics in the drill head, typically in the form of a sonde. Sondes are currently available in a variety of sizes, from a variety of manufacturers and include 2 basic types; a type powered by a battery and a type powered by a wire that is threaded through the drill string to an above-ground power source.
An example of a battery powered sonde and its mounting configuration within a drill head is described in U.S. Pat. No. 5,633,589. FIG. 4 of '589 illustrates a drill head with the adapter assembly connected on one end to the drill string and to the drill bit at the other end. This is a schematic representation illustrating primarily the electronic package. This arrangement illustrates that the adapter assembly is configured to hold the sonde or transmitter which is generally cylindrical and whose diameter is significant in relation to the diameter of the drill rod. This static section of the adapter assembly has become known as the sonde housing.
Other examples of sonde housings can be seen in U.S. Pat. No. 5,799,740 (hereinafter '740), U.S. Pat. No. 5,253,721 (hereinafter '721), and U.S. Pat. No. 6,260,634 (hereinafter '634). FIG. 11 of '740 more closely exemplifies the design of typical sonde housings. The housing is configured to accept a sonde, to mate to a drill bit, to mate to the drill string, and to provide a passage for fluid. The mechanical configuration is such that a cavity for the sonde is positioned off center and located as close as possible to the edge of the adapter, as constrained by minimum material thickness. This provides a maximum cross-sectional area of the fluid passages, also constrained by minimum material thickness surrounding the passage. The location of the fluid passages is thus close to the outer diameter of the sonde housing.
In order to manufacture typical sonde housing passages, the sonde housing is made as two pieces. The cylindrical main section, illustrated as FIG. 11 in '740, includes a threaded section with an inner diameter sufficiently large to allow the fluid passages to be manufactured with normal drilling. This thread is much larger than the threads utilized on the drill rod. Thus a second piece, illustrated in FIG. 10, screws into these large threads on one end and adapts to the threads of the drill string on the other end. In this manner, the sonde housing is constructed from multiple parts that are screwed together. The sonde is installed into the sonde housing by separating the two pieces at this threaded connection. This type of sonde housing is referred to as an end load sonde housing as the sonde is inserted from an end of the sonde housing.
The cylindrical sonde housing illustrated in the '634 patent also utilizes a two piece construction. FIG. 2 illustrates a similar main section adapted to accept a sonde, adapted to a drill bit on one end, and to a second adapter on the opposite end. Rather than utilizing a threaded connection between the main section and the adapter, this sonde housing utilizes a splined connection. One such adapter is illustrated in FIG. 22 of U.S. Pat. No. 6,148,935 (hereinafter '935), and herein incorporated in its entirety by reference. Here again, the inner diameter of the splined connection is such that the fluid transfer holes can be drilled with normal drilling techniques. The sonde housing illustrated in the '634 patent is generally referred to as a side load housing as the sonde housing includes a door that covers the sonde cavity mounted on the side of the sonde housing and the sonde is accessed from the side.
FIG. 1 of '935 and FIG. 3 of '721 illustrate the difficulty of manufacturing a one-piece sonde housing. In '935 the fluid transfer holes are drilled at an angle, adding cost and complexity to the assembly. In '721 the fluid transfer holes require 4 separate, intersecting drilled holes creating 90-degree angles in the fluid pathway. This configuration results in significant flow restriction.
In addition to providing a flow passage, the sonde housing also serves to support and position the sonde. U.S. Pat. Nos. 6,260,634 and 6,148,935 illustrate the use of a splined connection between the sonde housing and the drill bit that can only be assembled in one rotary orientation. This, combined with the rotary orientation control of the sonde, coordinates the orientation between the sonde and the drill bit. This arrangement is dependent on the splined connection, which results in restricting the variety of drill bits that can be utilized with the housing, as not all bits include such splines.
Other mounting requirements for sondes include vibration isolation, particularly when the adapter assembly includes a hammer, and/or provision for a wire passage for use with a wire-line sonde. The sonde housing, being located near the drill bit, is subjected to severe load conditions. The mechanical rigidity and assembly characteristics affect the durability of the sonde housing. The requirement for durability is exemplified by the existence of industry standards for certain types of drilling components. For instance, the American Petroleum Institute has adopted a specific thread configuration for use with drilling components that imposes an additional physical constraint affecting the mechanical configuration of the sonde housing.
SUMMARY
One aspect of the present invention relates to an enhanced sonde housing for use in the horizontal directional drilling industry. Another aspect of the present invention relates to the method of manufacturing the enhanced sonde housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of one embodiment of a drill head assembly according to the present invention mounted onto a drill string in a first set-up with a bit adapted for boring in soft rock;
FIG. 2 is a side view of another embodiment of a drill head assembly according to the present invention mounted onto a drill string in a second set-up with a bit adapted for boring in soils;
FIG. 3 is a side view of yet another embodiment of a drill head assembly according to the present invention mounted onto a drill string in a third set-up with a hammer and bit adapted for boring in hard rock;
FIG. 4 is an exploded view of a sonde housing assembly according to the present invention;
FIG. 5 is an end view of a sonde housing according to the present invention;
FIG. 6 is a cross section of the sonde housing of FIG. 5 taken along line 6 — 6 ;
FIG. 7A is an exploded side view of a sonde housing according to the present invention prior to assembly for welding;
FIG. 7B is an assembled top view of the sonde housing of FIG. 7A ;
FIG. 8 is an enlarged cross section of the sonde door retaining pin section shown in FIG. 6 ;
FIG. 9 is an isometric view of the sonde mounting block according to the present invention;
FIG. 10 is a cross-sectional view of the sonde mounting assembly according to the present invention;
FIG. 11 is an isometric view of a typical sonde;
FIG. 12 is an exploded view of an alternate sonde mounting assembly according to the present invention;
FIG. 13 is a cross-sectional view of the wireline routing for a wireline sub according to the present invention;
FIG. 14 is an isometric view of a second embodiment of a sonde rotary orientation control including a tab on the door that engages a gear on the sonde;
FIG. 15A is a longitudinal cross sectional view of a third embodiment of a sonde rotary orientation control including a tab on the door that engages a plug;
FIG. 15B is an enlarged view of the rotary orientation control section of FIG. 15A ;
FIG. 16A is a longitudinal cross sectional view of a fourth embodiment of a sonde rotary orientation control including a tab on the door that engages an o-ring in contact with the sonde;
FIG. 16B is an enlarged view of the rotary orientation control section of FIG. 16A ;
FIG. 17A is a longitudinal cross sectional view of a fifth embodiment of a sonde rotary orientation control including a tab on the door that engages an o-ring in contact with a plug that engages the sonde;
FIG. 17B is an enlarged view of the rotary orientation control section of FIG. 17B ;
FIG. 18 is a radial cross sectional view representative of the sonde door and plug within the housing of FIG. 15B taken along the line 18 — 18 ; and
FIGS. 19A–19E are schematic illustrations of the stages of manufacturing for an alternate method of manufacturing a sonde housing of the present invention.
DETAILED DESCRIPTION
With reference now to the various figures in which identical elements are numbered identically throughout, a description of various exemplary aspects of the present invention will now be provided. The preferred embodiments are shown in the drawings and described with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the embodiments disclosed.
Referring now to the drawings, FIG. 1 illustrates one embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. Drill string 10 terminates at a first end of a drill head assembly 14 and connects at an opposite end to a drilling machine (not shown) capable of providing rotation and longitudinal power. The drill string 10 is typically constructed of hollow tubing and is capable of transferring pressurized fluid. In the configuration shown in FIG. 1 , a drill bit 12 connects to an opposite end of the drill head assembly 14 .
The drill head assembly 14 consists of a rear transition sub 16 , a rear adapter sub 18 , a front adapter sub 20 and the sonde housing assembly 50 . In this configuration the rear adapter sub 18 is configured to mate with the rear transition sub 16 in order to utilize a joint 24 . An exemplary joint used in this type of configuration is described in U.S. Pat. No. 6,148,935, which is herein incorporated by reference in its entirety. Joint 24 allows for convenient separation between the drill string 10 and the rest of the drill head, in particular, the rear transition sub 16 remains attached to the drill string 10 while the remaining portion of the drill head assembly 14 and the drill bit 12 are removed. In use, this configuration requires less tools to remove the portion of the drill head assembly and drill bit after drilling a pilot hole and attach a reamer having a similar transition sub. In the embodiment of FIG. 1 , the backreaming would be completed without the sonde housing assembly 50 .
FIG. 2 illustrates an alternative embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. In this illustration, the drill head assembly 14 ′ does not include a rear transition sub, as in 16 of FIG. 1 , but does include a front transition sub 22 configured with a joint 24 ′ and a front adapter sub 20 ′. This configuration allows a drill bit 12 ′ and front transition sub 22 to be removed with minimal tools. A reamer (not shown) configured with a splined transition sub that mates with joint 24 ′, similar to that found on transition sub 22 , can then be connected. In the embodiment of FIG. 2 , the sonde housing assembly 50 is left installed during backreaming.
FIG. 3 illustrates yet another embodiment of a drill head set-up having a sonde housing assembly 50 according to the present invention. An exemplary joint used in this type of configuration is described in U.S. Pat. No. 6,148,935, which is herein incorporated by reference in its entirety. Drill head assembly 14 ″ includes a rear adapter sub 18 ″, a sonde housing assembly 50 , a front adapter sub 20 ″, and a hammer 26 . The hammer includes a front shaft 28 capable of supporting a bit 12 ″.
From these three exemplary embodiments it is obvious that there is a multitude of possible set-ups, each potentially affecting the configuration of the sonde housing assembly 50 . These three are only typical examples, and many other configurations and embodiments are possible. As a result of the many various applications and requirements, there are currently a number of specific configurations of sonde housings available. It is an desirable to provide a universal sonde housing that is capable of being used in a wide variety of drill head configurations that also provides minimum flow restriction, maximum mechanical rigidity, flexibility in mounting arrangements for differing sondes, and flexibility in accepting adapters between the housing and drill bits or drill string. In addition, the use of sondes during backreaming is possible and a sonde housing capable of handling relatively large flow rates with flexibility in accepting adapters will be an improvement.
FIG. 4 illustrates the components found in the sonde housing assembly 50 according to the principles disclosed. The main component is main housing 100 . A cavity 102 is accessible by removing a sonde door 52 . The sonde door 52 is retained on one end by a tab 58 , which engages into a slot 104 (see FIG. 6 ) of the main housing 100 . The other end is retained by a door latch pin 54 which is installed into hole 106 . A surface 120 , best shown in FIG. 6 , supports the sonde door 52 . The door latch pin 54 is then retained in the main housing 100 by a retainer pin 56 which is driven into a through hole 108 that intersects hole 106 as illustrated in FIGS. 6 and 8 . In order to remove the sonde door, the retainer pin 56 is easily removed with standard tools, including a hammer and punch. The door latch pin 54 is then free to be removed by lifting the sonde door 52 in an angular motion, pivoting around its tab 58 , until the sonde door and latch pin clear the sonde cavity.
The sonde 60 fits into cavity 102 . The cavity 102 is defined by a depth 112 as illustrated in FIG. 6 and a width 110 as illustrated in FIG. 7B . The sonde 60 is supported by mount blocks 64 A & 64 B, one on each end. As illustrated in FIG. 9 , the mount blocks 64 A and 64 B include a cavity 65 with an inner diameter selected relative to the outer diameter of sonde 60 to position and support sonde 60 . The cavity 65 may include a groove manufactured to capture an O-ring 151 to support and center the sonde 60 .
The mount blocks 64 A and 64 B are supported within the cavity 102 . The cavity 102 is defined by the main housing 100 and the sonde door 52 . The blocks 64 A and 64 B are constructed so that their width 111 is slightly less than the cavity width 110 . In this illustrated embodiment the sonde door 52 includes a slot of depth 154 , as illustrated in FIG. 10 , that cooperates with cavity 102 to retrain the blocks 64 A and 64 B. The height 113 of blocks 64 A and 64 B is slightly less than the sum of cavity depth 112 and the slot depth 154 respectively. In this manner, the blocks are mounted so that they are free to move, specifically, slide longitudinally relative to the sonde housing 100 and sonde door 52 , yet are securely supported when the sonde door 52 is installed.
The mount blocks 64 A and 64 B are constructed from any material that will aid in properly supporting the sonde 60 . The preferred material is a type of plastic so that the cavity 65 can be sized to fit the sonde 60 relatively tight without causing any damage to the sonde 60 . Several configurations of mount blocks 64 A and 64 B can be made available, each having a cavity 65 specific for a certain type of sonde, yet with the same outer dimensions (i.e. width 111 and height 113 ). In this manner the main housing 100 remains unchanged, while the assembly is capable of accepting sondes 60 of various diameter and or configuration.
The bottom surface 114 of the cavity 102 and the bottom surface of the sonde door 52 support the mount blocks 64 A and 64 B along the radial axis. They are supported along the axis perpendicular to the radial axis and the longitudinal axis by the side surfaces 118 of the cavity 102 . Along the longitudinal axis the mount blocks 64 A and 64 B are supported by axial vibration isolators 66 which are supported by end surfaces 120 , which are effective due to the built-in clearances in the block mounting. The assembly is illustrated in FIG. 10 .
The axial vibration isolators 66 can be constructed of a variety of materials, selected for the dynamic compression characteristics, to act to reduce the vibration loading transferred to the sonde 60 . This is useful in applications involving a percussive hammer where the percussive hammer produces primarily longitudinal vibrations. Isolation in the other two axis may be provided by constructing the mount blocks 64 A and 64 B of material with appropriate compression characteristics or implementing non-axial vibration isolators between the support blocks 64 A and 64 B and surfaces 118 and 114 .
One possible embodiment of such isolators is illustrated in FIGS. 9 and 10 . External o-rings 152 are designed to fit into grooves machined on the outer surface of blocks 64 A and 64 B. Proper clearances between the block dimensions 111 and 113 and the cavity dimensions 110 and ( 112 + 154 ) need to be determined for the vibration isolation to be effective.
In addition to being supported along the longitudinal axis, the longitudinal axis of the sonde 60 is ideally aligned with the longitudinal axis of the sonde housing assembly 50 . This is useful in certain applications that require precise control of the grade of the bore, such as installation of gravity sewers. Commonly, traditional sondes include pitch sensors capable of measuring the pitch of the longitudinal axis, for example, when the sonde housing is level, the measured pitch is zero. However, there are inherent manufacturing tolerances and stack-up problems of the mounting component that can introduce some angularity error. Thus, it is desirable to improve the process of drilling with sondes by providing a mechanical adjustment that can be used to compensate for the error inherent with the sonde. Also, sonde housings are generally constructed to approximately align the longitudinal axis of the sonde with the longitudinal axis of the sonde housing. However, the precision of the orientation of the sonde's mounting in the sonde housing may also introduce unwanted alignment error. In order to correct such errors, an adjustment assembly 171 as shown in FIG. 12 can be utilized to correct the alignment.
In utilizing an adjustment assembly 171 , the block 64 B is replaced with the assembly 171 shown in FIG. 12 . The adjustment assembly includes an adjustment screw 170 capable of moving the centerline of a supporting cap 174 , in a first direction, relative to an outer surface 178 of a lower base 176 . The adjustment screw 170 threads into upper base 184 and seats against upper surface 186 of the lower base 176 such that if the screw 170 is screwed into the upper base 184 , the upper base 184 will move away from the lower base 176 . The supporting cap 174 engages with the upper base 184 and is thus moved. Screws 182 are utilized to lock the upper base 184 to the lower base 176 once the proper setting is achieved. The lower base 176 will seat in the cavity 102 and be supported by surface 114 .
In assembling the components, the sonde will be positioned in the supporting block 64 on one end, and in the adjustment assembly 171 on the other end (e.g. a similarly sized cavity within the supporting cap 174 (not shown) as that of the supporting block cavity 65 ). That assembly is then inserted into the cavity 102 , supporting the sonde. The sonde housing assembly is positioned to be at a known pitch, typically level. The reading from the sonde is checked. The screws 182 and 170 can then be manipulated until the sonde pitch reading is correct. Once correct, an isolator block 180 is installed on top of screws 182 and the upper base 184 . When the sonde door 52 is installed, this assembly is slightly compressed to assure the lower base 176 remains properly positioned against surface 114 of the sonde housing 100 .
Screws 172 are also provided to position the supporting cap 174 in relation to the upper base 184 in order to provide adjustment in the other plane.
Referring now to FIGS. 10 and 13 , a cylindrical plug 62 , orientation tab 68 and screw 70 define the rotary orientation of the sonde within the assembly. The mount blocks 64 A and 64 B are rectangular in cross section, fitting into cavity 102 that is likewise rectangular in cross section. Thus mount blocks 64 A and 64 B are fixed relative to the main housing 100 . The plug 62 is cylindrical and fits into the cylindrical cavity 65 within mount block 64 A. The sonde 60 , typically cylindrical, also fits into the cylindrical cavity 65 of mount block 64 A.
In one embodiment, the sonde 60 includes a slot 61 that assists in defining its rotary orientation, as shown in FIG. 11 . Upon installing the plug 62 , mount blocks 64 A & 64 B, orientation tab 68 , sonde 60 and isolators 66 into the cavity 102 , the sonde 60 may be rotated within cavity 65 of mount blocks 64 A and 64 B. As the sonde 60 is rotated, the plug 62 also rotates relative to mount blocks 64 A and 64 B. Once the sonde 60 is positioned in the proper rotary orientation, a screw 70 is installed through the mount block 64 A and into the plug 62 locking the plug into position and thereby defining the rotary orientation of the sonde 60 relative to the mount blocks 64 A and 64 B, and ultimately relative to the main housing 100 . This embodiment requires a simple through hole be provided in the mount block 64 A for the screw to pass through. In an alternate embodiment, not shown, mount block 64 A could include a threaded hole. A set screw could engage these threads and then simply contact the plug, without extending into the plug, to lock the plug into position.
Yet another alternative embodiment that rotationally orients a sonde is illustrated in FIG. 14 . In this embodiment the sonde door 52 includes a rib 158 that projects downward to engage with a gear 156 . The gear 156 is secured to the sonde 60 . In this configuration, the rotary orientation of the sonde 60 is set or locked upon installation of the sonde door. Additional embodiments are illustrated in FIGS. 15A–B , 16 A–B and 17 A–B wherein the rib engages: the plug 62 , as shown in FIGS. 15A–B ; an o-ring 153 that is in contact with the sonde 60 , as shown in FIGS. 16A–B ; or an o-ring 155 that is installed onto the plug 62 , as shown in FIGS. 17A–B . In all of these embodiments, the rib restrains the rotation of the sonde whenever the door 52 is installed.
The rotary orientation of the sonde ultimately needs to be defined relative to a directional control element of a drill head. In the horizontal directional drilling process, the ability to control the direction of the boring is a result of some physical property of the drill bit, or of some other physical property of the drill head. There are a variety of designs available that provide directional control, each having its own benefits associated with various soils or setups. The operators typically know how the setups will steer in the ground and are thus capable of positioning the assembled drill head in a rotary position to steer in a certain direction. For instance an operator is expected to be able to assemble a drill head and roll the drill head into a rotary position so that the drill head steers upward. This is typically known as steering at 12:00. Likewise the operator is expected to be able to position the drill head in the rotary position to steer right, 3:00, downward, 6:00, or left 9:00.
The method of setting the rotary orientation of a sonde within a drill head according to the principles of this disclosure are as follows:
1) operator assembles the drill head completely, including drilling bit, except for installation of the sonde door 52 ; 2) operator positions the drill head into any desired rotary position (ie: 12 o'clock); 3) operator checks the output from sonde 60 via sonde signal receiver/decoder and then modifies the rotary orientation of the sonde 60 by rotating it within the cavity 102 until it is reading the correct orientation, as determined by how the drill head was previously positioned; and 4) operator then installs screw 70 through the mount block 64 a and into the cylindrical plug 62 to lock the assembly into position or simply installs the sonde door with one of the embodiments illustrated in FIGS. 14 , 15 , 16 and 17 .
One advantage of this method is that this method allows for an infinitely accurate rotational orientation of the sonde to the sonde housing, and allows the operator to modify the position of the sonde in the cavity. Another advantage of this method is that this method allows the sonde housing to be adaptable to any drill head assembly. In many instances the directional control element of the drill head relative to the sonde housing assembly will be defined by the rotary orientation of the front adapter sub 20 as located on the sonde housing assembly 50 ; this connection is seldom modified. In such cases, the mounting block 64 A, plug 62 and screw 70 can be left assembled when changing drill bits or sondes. Thus, the process of orienting the sonde is not necessary each time the drill head is worked on. It is expected that once assembled, the drill heads are typically dedicated to a certain type of set-up, and adjustments are not performed frequently. It is therefore beneficial that one sonde can easily be adapted to any known drill head set-up.
Aside from the variations in drill head physical characteristics, and physical variations of sondes, there are two basic types of sondes: a battery powered sonde and a wire line powered sonde. FIG. 13 illustrates the sonde mounting of the present disclosure adapted for use with a wireline sonde.
In FIG. 13 the wire line is threaded through the drill string from the ground surface to the drill head in any known manner. Present drill head configurations provide for a wire routing path that allows the wireline to be connected to a sonde. This routing generally involves a strain relief plug 74 , strain relief 76 and tapped hole 150 , as illustrated in FIG. 13 . The tapped hole 150 projects from one end of the main housing 100 into the cavity 102 . When a battery powered sonde is used, there is no need for anything to project through this hole, so a plug 72 (shown in FIG. 4 ) is installed. However, when a wireline sonde is used, this plug 72 is removed and a similar plug (i.e. strain relief plug 74 ) is installed.
The strain relief plug 74 includes a cavity large enough for a strain relief 76 to be installed. The strain relief 76 is cylindrical and includes a through hole aligned with the axis of the outer cylindrical surface of the strain relief. The through hole is sized to fit tightly over the outer diameter of a wire 25 projecting out of the wireline sonde. The wire 25 from the wireline sonde is routed through a hole 160 in 64 a or 64 b , then through a hole 162 in isolator 60 , then through a slot 164 in main housing 100 . (The slot 164 is also shown in FIG. 7B .) The wire 25 is routed from slot 164 through a threaded hole 150 . Strain relief 76 is then slid over the wire and into the void in the strain relief plug 74 .
Once these components are assembled, the strain relief plug 74 is assembled into the threaded hole 150 and tightened. The threaded hole 150 includes a larger threaded section and a smaller through hole section so that strain relief 76 can be inserted through the threaded diameter, but cannot pass through the smaller through hole section. Thus as the strain relief plug 74 is tightened, strain relief 76 is compressed thereby restricting the movement of the wire 25 and sealing the wireline to prevent transfer of fluid into cavity 102 . In this manner the sonde housing assembly is adaptable to allow use of wireline sondes or battery powered sondes.
Another element that makes the sonde housing adaptable is the use of a threaded connection on each end of the main housing 100 . Referring back to FIG. 6 , the main housing 100 is shown as a one-piece design having three sections. The three sections may have standard API (American Petroleum Institute) threads on each end. The three sections of the main housing 100 include: a center section 130 , a top end section 132 and a bottom end section 134 . FIG. 7A illustrates how these three sections fit together.
The threaded connections of the top end section and the bottom end section 132 and 134 of the illustrated embodiment are female threaded connections. It is contemplated the threaded connections of the top and bottom end sections may also include male threaded connections. In general the threaded connection preferably include standard API tapered thread connection having a major diameter and a minor diameter.
The top end section 132 includes a projection 140 of length 141 . Center section 130 includes a cylindrical cavity 142 of depth 143 . The cavity depth 143 is deeper than the projection length 141 which results in a gap or void 136 as shown in FIG. 6 . This void is utilized as a part of the fluid flow path. The bottom end section 134 has similar features including a projection 140 ′ of length 141 ′ and center section including a cavity 142 of depth 143 . It is not necessary the projection 140 have a mating configuration to the cylindrical cavity 142 . A portion of the projection 140 may be utilized to assist in proper orientation of the components, and is optional. One key aspect of this configuration is the resulting void 136 created by the cavity 142 in the center section 130 which is utilized as a part of the fluid flow path.
The complete fluid flow path through the main housing 100 in FIG. 6 as viewed from left to right, starts through the top end section 132 which will accept fluid from the drill string 10 , as delivered through the rear adapter sub 18 , as in FIG. 2 . The fluid is transferred into the void 136 and then into drilled holes 138 . Exiting the drilled holes 138 , the fluid encounters the other void 136 and is directed through the bottom end section 134 . With this construction, the location of the drilled holes 138 in the center section 130 is not affected by the dimensions of the threaded connections of either the top end section 132 or the bottom end section 134 . Both sections are illustrated with female threads in FIGS. 6 and 7 , but there is no restriction on the configuration selected. The threads could be any size, male or female.
The fluid flow advantages of this configuration are in the size of the drilled holes 138 and the flow transition required for the fluid to transfer into these holes. The void 136 provides the fluid with a gentle transition in contrast to 90 degree turns found in conventional configurations. The gentle transition provided by the voids thereby reduce fluid flow constrictions.
In addition, the size of the drilled holes 138 can be optimized easily and efficiently as the hole locations are not affected by the physical characteristics of the threaded connections. Thus, this configuration allows the center section to be constructed to maximize its strength while at the same time maximizing the fluid flow path provided.
The completed main housing 100 is thus constructed by manufacturing a top end section 132 a bottom end section 134 and a center section 130 . The center section is constructed to provide a cavity 102 for mounting a sonde while at the same time provide fluid flow passages via drilled holes 138 and cavities 142 . The end sections 132 and 134 are constructed with threaded connections and preferably joined to the center section 130 by welding.
One method of manufacturing the main housing involves the following:
1) machine holes 138 in housing section 130 ; 2) machine pockets 142 in both ends of housing section 130 ; 3) machine end pieces 134 and 132 except for the thread connection; 4) leave overstock on outer diameters of parts 132 , 134 , and 130 for clean up machining; 5) slide end 140 of part 132 into pocket 142 and slide end 140 of part 134 into opposite pocket 142 of part 130 ; 6) clamp three pieces together to hold orientation; 7) performing welding operation in v-grooves generate at mating location of parts 132 , 130 , and 134 ; 8) post heat treatment;
a) stress relieve assembly b) throughly harden assembly to Rc 28 – 32 ′ and
9) post heat treat, machine the following geometric features:
a) threaded ends b) outer diameter c) sonde pocket and related geometry
An alternate method of manufacturing a sonde housing is illustrated in FIGS. 19A–19E . This method starts with a single piece of bar stock wherein the fluid transfer holes are drilled in step 1, shown in FIG. 19A . Step 2, shown in FIG. 19B involves plugging those fluid transfer holes in a manner that the plugs will become substantially integral with the bar stock material. This process may involve several optional methods. The method illustrated being to insert plugs that are larger than the holes such that they are press-fit into the holes. These plugs could then be further retained by heating the plugs nearly to the melting temperature to effectively bond them to the bar stock material. Many other techniques could be practiced. Step 3, shown in FIG. 19C involves machining threads and step 4, shown in FIG. 19D involves machining annular cylindrical voids with an outer diameter that exceeds the inner diameter of the threads such that the originally drilled fluid transfer holes are fluidly connected to the annular cylindrical voids extending outwardly from the threads. Step 5, shown in FIG. 19E involves machining the sonde cavity.
The embodiments of the present disclosure may be used in a variety of applications. For example, the sonde housing is designed to be utilized in multiple applications of drilling including: dirt boring, rock boring, sewer product installation, back reaming, percussive drilling, and other drilling applications.
In addition, it is obvious that many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A sonde (transmitter) housing having a one-piece design for improved housing rigidity. The housing includes a mechanically-adjustable mounting configuration adaptable to a variety of sonde applications. A method of making the sonde housing in a one-piece design and infinitely orienting the sonde clocking electronics.
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BACKGROUND OF THE INVENTION
1. Field Of The Invention
The present invention provides a method of opening and extending fractures in a subterranean formation surrounding a wellbore penetrating the formation. The invention is particularly useful in formations which are naturally fractured such as coal seams, shales and chalk formations.
2. Brief Description Of The Prior Art
In many types of wells penetrating subterranean formations a casing is placed in the borehole and the casing then is perforated to establish communication between the wellbore and the subterranean formation. The casing typically is cemented in place within the borehole. The formation of perforations in the casing preferably establishes communication through the casing and surrounding cement into the adjacent subterranean formation. It is often desirable to fracture the subterranean formation in contact with the perforations to thereby facilitate the flow of any hydrocarbons or other fluids present in the formation to the wellbore.
Various methods and apparatus have been used to effect perforation of a well casing and fracturing of a subterranean formation. Perforations have been produced mechanically such as by hydrojetting and through the use of explosive charges such as in jet perforating. Fracturing has been accomplished by introducing an aqueous or hydrocarbon liquid into the formation through the perforations at a rate and pressure sufficient to fracture the subterranean formation. In some instances, the fracturing fluid may include a propping agent to prop the created fracture open upon completion of the fracturing treatment. The propped fracture provides an open channel through which fluids may pass from the formation to the wellbore.
Fracturing also has been accomplished by the detonation of explosives within a portion of a wellbore or the ignition of a quantity of a combustible gas mixture confined within a wellbore which produces a high pressure wave that fractures the formation surrounding the wellbore. Combustible or explosive liquids also have been utilized to fracture a subterranean formation. In this instance, the liquid reactants are injected into a wellbore and into the adjacent porous portions of the formation after which the liquid reactants are detonated to produce fractures in the formation.
SUMMARY OF THE INVENTION
The present invention provides an improved method of producing and extending fractures in formations which exhibit non-linear elastic characteristics or in naturally fractured formations and an equivalent system of stimulation of formations which do not contain natural fractures. The method is accomplished, in part, by the introduction of a gaseous explosive comprising a gaseous fuel and an oxidizer and optionally an inert gas into fractures contained in a subterranean formation and igniting the explosive within the formation fractures. The detonation, energy of the explosive can be controlled by the quantity of inert gas present and the pressure of the gas at the time of detonation. The detonation results in sufficient pressure to open the fracture, extend the fracture and produce sufficient rubble to prop the fracture in an opened condition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention has general application to wells for the extraction of any fluid from a subterranean formation as well as for solution mining wherein fluids are injected and thereafter recovered with dissolved minerals therein. The present invention is particularly applicable to the recovery of gas or petroleum from naturally fractured subterranean formations and formations which can be hydraulically fractured initially to create the fracture flow path for introduction of the gaseous explosive. The use of the present invention is particularly beneficial in shale, chalk and fractured coal-bearing formations.
In a typical application, a wellbore is drilled from the surface of the earth to a desired depth within a subterranean formation. Casing may be placed within the wellbore and cemented or otherwise bonded in place within the wellbore. If the casing extends the full depth of the wellbore to a desired zone, the casing may be perforated or slotted by well known conventional methods to effect communication between the wellbore and the formation.
If the casing does not extend the full depth of the wellbore, communication is established through the uncased zone without perforation or slotting. A packer or packers then may be set in the casing or wellbore to isolate a particular portion of the wellbore which is to be stimulated. The packer or packers may be any one of the various commercially available types.
A tubing string then can be placed within the casing and passed through the upper packer to reach an isolated zone in the wellbore which is to be stimulated. The explosive gas then is introduced into the formation from the wellbore, either through natural or artificially created fractures present therein. The explosive gas is comprised of a mixture of an oxidizer and a fuel. The mixture also may include an inert gas, such as for example nitrogen, to assist in control of the detonation rate and the gas mixture pressure level in the formation. Preferably, the oxidizer is oxygen gas or an oxygen containing gas such as air. The fuel preferably comprises methane, ethane, ethylene, propane or any of the various other low molecular weight hydrocarbons which have a sufficiently low vapor pressure to be a gas at the temperature and pressure at which the stimulation treatment is effected. Preferably the constituents of the explosive gas are admixed or combined immediately prior to introduction into the formation. This may be effected, for example, by injecting the oxidizer down the annulus created by the casing and tubing string and hydrocarbon fuel down through the tubing such that the gases combine in the vicinity of the fractures in the formation. Such a method of introduction minimizes the amount of explosive gas mixture present in the wellbore prior to introduction into the subterranean formation.
The explosive gas is introduced at a rate and pressure sufficient to ensure that the mixture enters the fractures in the formation intersecting the wellbore. The fractures may be either natural fractures existing in the formation to be treated such as those in a coal bed or faulted chalk formation or they may be artificially induced fractures produced by a previously performed hydraulic fracturing treatment using an aqueous or hydrocarbon fluid. Numerous methods of effecting hydraulic fracturing treatments are known to individuals skilled in the art and substantially any of such methods may be utilized to create fractures extending from the wellbore into the formation.
Previously, it was not believed that it would be possible to detonate a gas contained in the narrow confines of a fracture since it generally is not possible to detonate a gas at atmospheric pressure contained in tubing having a diameter below about two inches. However, the surprising discovery has been made that when an elevated pressure is applied to the gas it is possible to detonate a mixture of nitrogen, oxygen and propane in a tubing having a diameter of only 0.083 inches down the length of the tubing. This discovery permits the use of an elevated pressure explosive gas to create and extend fractures in subterranean formation. Surprisingly, detonation of the explosive gas can result in an increase in the width of a fracture by a factor of from about 3 to 6 to as much as about 12 times its initial width. Further, the detonation results in the formation of sufficient rubble or formation particulate that the fracture retains a substantial amount of its opened width through propping of the fracture by the rubble or particulate. The movement of the pressure wave down the length of the fracture as the gas detonates down the fracture also results in lengthening of the fracture by the pressure applied at the end of the fracture. The force generated by the detonation is such that the formation may permanently yield thereby reducing the closure stress placed upon the created fracture as a result of passage of the momentary high pressure wave through the formation.
The detonation of the explosive gas may be effected by any suitable conventional means such as an explosive charge connected by a wireline to the surface in the same manner as perforating charges are initiated, an exploding bridge wire, in some instances an electric spark, an electrically heated filament or even a blasting cap. Substantially any means of detonation may be utilized so long as it effects a detonation of the explosive gas in the fractures within the subterranean formation.
Energy levels generated by the detonation of the explosive gas in the formation can be varied by adjusting the oxidizer and fuel concentrations. Preferably, the oxidizer and fuel are utilized in approximately stoichiometric ratios. The ratio may be varied for the oxidizer to inert gas mixture in an amount of from about 15 to 100% and most preferably only from about 21 to 40%. The ratio may be varied from stoichiometric for the fuel from about 80 to 150% of stoichiometric. The minor change of from about 21% oxygen to about 25% oxygen in the mixture can result in an energy increase upon detonation of a fuel, such as propane, of about 18% which can translate into an ability to extend a fracture having a smaller width than otherwise might be possible. Generally, the quantity of explosive gas utilized will depend upon the size and length of the fracture or fractures that it is desired to produce. Generally a typical treatment will utilize from about 200,000 Standard Cubic Feet (SCF) of gas at atmospheric temperature and pressure to about 3,000,000 SCF. The ability to introduce the gaseous explosive into the fractures in the subterranean formation will permit explosive to penetrate up to several hundred feet from the wellbore and in some instances in excess of 1000 feet prior to detonation. Thus, results in a substantially greater fracture size than could be accomplished by detonation of an explosive merely within a wellbore.
In the particular application of solution mining, the method of the present invention can substantially increase the surface area of a subterranean mineral-bearing zone for contact with a solvent or extractant. In this instance a wellbore is drilled into the mineral-bearing formation and if no natural fractures exist a hydraulic fracturing treatment can be utilized to create fractures in the formation. The explosive gas mixture then is introduced into the fractures in the mineral-bearing zone and ignited as previously described. In this instance, the amount of explosive energy is determined to achieve the effect of maximum rubblization of the mineral-bearing zone and the oxidizer/fuel ratios are adjusted accordingly. Thereafter a suitable solvent or extractant for the mineral that is desired to be recovered can be introduced into the formation to contact the rubblized formation material to dissolve or extract the desired mineral from the formation. The mineral-laden solvent or extract then can be recovered from the formation and the mineral recovered from the solution mining fluid.
To further illustrate the present invention, but not by way of limitation, the following example is provided.
EXAMPLE
A well drilled for methane production from a coal seam is 2400 feet deep with 51/2 inch casing down to 2250 feet and open hole below the casing. The 150 feet of open hole contains 60 net feet of coal. Tubing with an outside diameter of 23/8 inch is placed in the well to a depth of 2240 feet. A tool on the end of the tubing contains nozzles for atomizing propane into the annular area and a collar to support a wireline conveyed detonator. The detonator is designed such that 10 feet below the tubing is an electric detonator and explosive booster pellet. The detonator is placed down the tubing on the wireline until it is supported by the collar in the tool at the bottom of the tubing.
The well then is fractured in a conventional manner with a foam fracturing fluid containing fluid loss additives. The foam is pumped down the annulus at a rate of 60 barrels per minute. This rate is expected to create a fracture width of approximately 0.6 inches. A total of 600 barrels of foam are injected to initiate the fracture and control fluid loss. Then, the foam injection down the annulus is replaced with a mixture of 25% oxygen and 75% nitrogen. Propane is injected into the tubing at a rate of 50 gallons per minute such that the propane and the nitrogen/oxygen mixture reach the depth of 2240 feet at approximately the same time. Although the propane is introduced as a liquid in the tubing, it flashes to a gas when sprayed into the bottom of the casing. Total injection rate of propane, oxygen and nitrogen is equivalent to 60 barrels per minute at bottom hole treating pressure and temperature. The lower viscosity of the gaseous mixture will allow the fracture width to close to approximately 0.25 inches. A total of 1800 barrels of the explosive mixture is injected before displacement begins. This volume is expected to extend the fracture and explosive mixture a distance greater than 1500 feet from the wellbore. Nitrogen is used to displace the nitrogen/oxygen mixture and water is used to displace the propane. The displacement is timed such that both the propane .and nitrogen/oxygen mixture is displaced at approximately the same time. Once the fuel in the tubing and oxidizer in the annulus are displaced, all injection stops.
When the displacement is 95% complete, the detonator is activated by electrical signal down the wireline. The detonation moves from the wellbore and out into the fractures. The pressure is calculated to increase between 25 and 40 times the original fracturing pressure. Velocity of the detonation wave will exceed 6000 feet per second. The fracture may open to a width of as much as 2.5 inches which would yield the formation. Rubble generated from the pressure wave will fall down the fracture, propping it open.
The well then is shut-in for a period of time to allow unburned propane to adsorb onto the coal and the heat to dissipate. Initial flowback will be at a slow rate while testing the oxygen concentration for safety.
The resulting fracture may be propped to a width greater than 0.5 inches. The shock wave which travels through the formation is at an angle to the hydraulic fracture. Tests have shown that this shock wave will reflect from existing natural fractures. This reflection causes a compression wave to become a tensile wave and allows these fractures to interconnect with the wellbore. It is this phenomenon which makes this treatment especially effective in formations which contain natural fractures.
A total of 1500 gallons of propane are injected. Combined with oxygen, this has the explosive energy of 27,800 pounds of conventional explosives.
While the foregoing invention has been described with regard to that which is considered to be the preferred embodiment thereof, it will be understood by those skilled in the art that changes or other modifications may be made in the foregoing method and apparatus without departing from the spirit and scope of the invention as set forth in the appended claims.
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The present invention provides a method of widening or extending fractures in a subterranean formation which intersect a wellbore to enhance the flow of fluids from the formation. The enhancement is achieved by introducing an explosive gas comprising a gaseous oxidizer and a gaseous fuel and optionally a quantity of inert gas into at least one fracture intersecting the wellbore and then detonating the explosive gas. The detonation produces a pressure wave which passes down the length of the fracture. The pressure wave can cause the fracture to extend and can cause the face of the fracture to yield whereby rubble is produced within the fracture which can prop the fracture in an open position.
Identical application of the method can be used to rubblize a formation for solution mining of minerals of said formation.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to a needle felting machine, or needle loom, for non-woven fabrics and, more particularly, to a system for guiding reciprocating needle boards of such needle looms in a rectilinear path.
BACKGROUND OF THE INVENTION:
Needle looms typically employ a pair of spaced connecting rods to reciprocate a needle beam with respect to a web of non-woven fabric being needled by the loom. The connecting rods are journaled at one of their ends on an eccentric cam or on a crank arm carried by a drive shaft in the loom, and are journaled at the other of their ends to an upper surface of the needle beam. Guide arrangements, including guide posts fixedly carried by the needle beam and slide bushings fixedly carried by the frame of the needle loom and in engagement with the guide posts, are generally employed to confine the reciprocating motion of the needle beam to rectilinear reciprocating motion. Examples of the foregoing prior art types of needle beam guide systems for needle looms may be found in the following patents: U.S Pat. No. 3,216,082, dated Nov. 9, 1965, to R. S. Goy; U.S. Pat. No. 3,602,967, dated Sept. 7, 1971, to Zocher et al; U.S. Pat. No. 3,798,717, dated Mar. 26, 1974, to R. E. Brochetti; and, U.S. Pat. No. 3,889,326, dated June 17, 1975, to T. Tyas.
During operation of a needle loom, the needles of the reciprocating needle beam penetrate the non-woven web that is being needled. Since the needles are densely mounted on the needle boards, significant forces are generated by the penetration of the needles into the web, which forces are resisted by the needle beam. These forces cause the needle beam to deflect slightly between and beyond the positions at which the connecting rods are mounted on the needle beam, resulting in a gull-wing-like curvature of the needle beam. Since the guide posts of the guide system which confines the reciprocating motion of the needle beam to rectilinear motion are mounted on the needle beam, either between the connecting rods or outside the connecting rods, an angular displacement of the guide posts occurs due to the deflection of the beam under load. This displacement is due to the fact that the guide posts remain perpendicular to the surface of the beam and, consequently, they lean toward their associated connecting rods and skew in their associated guide bushings.
This skewing action causes very heavy loads to occur on both the guide posts and the guide bushings of the guide system, creating excessive heat and requiring some form of lubricant to keep the heat generated under control. Since lubricants depend on seals to be contained, the prior systems have only been as good as the sealing arrangements employed to contain the lubricants in the guide bushings. However, these arrangements have been far from satisfactory, allowing contamination of the needled web due to lubricant leaking after only a relatively short service life. Moreover, since prior art forms of needle beam guide systems have involved the reciprocation of relatively massive guide posts in connection with maintaining rectilinear motion of the needle beams, the needling speeds that have been achievable in the past have been limited.
It is, therefore, a primary object of the present invention to provide an improved needle beam guide system in which the slide bushings are pivotally mounted to their supports in order to allow them to remain aligned with the guide posts under all operating conditions of the needle beam.
Another object of the present invention is to fix the guide posts of the guide system to the frame of the needle loom and to mount the guide bushings of the guide system on the reciprocating needle beam in order to reduce the mass that has to be moved during reciprocation of the needle beam.
Yet another object of the present invention is to resiliently mount the guide bushings inside the bushing housings so as to allow small movements to occur therebetween in order to absorb shock and some of the misalignment inherent in the operation of needle beams.
Further objects and advantages of this invention will become apparent as the following description proceeds.
SUMMARY OF THE INVENTION
Briefly stated, and in accordance with one embodiment of this invention, an improved needle loom comprises a frame; a needle beam; means, including a drive shaft and a crank means carried by the drive shaft and coupled to the needle beam, for reciprocating the needle beam relative to the frame; and, means, including a guide means fixedly carried by one of the frame and the needle beam and a slide means pivotally carried by the other of the frame and the needle beam and slidable relative to the guide means, for guiding the needle beam during its reciprocating movement relative to the frame.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as the invention herein, it is believed that the present invention will be more readily understood from the following description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevation view, with parts broken away and omitted for clarity, of a needle loom in accordance with this invention;
FIG. 2 is a side elevation view, on an enlarged scale, of a needle beam module, showing the drive and guide systems employed in controlling its reciprocating rectilinear movement;
FIG. 3 is an enlarged sectional elevation view, taken along the line 3--3 of FIG. 2;
FIGS. 4A and 4B show typical prior art drive and guide systems for a needle beam, with the needle beam being shown in an unstressed, elevated position in FIG. 4A and in a stressed, non-woven-web-penetrating position in FIG. 4B;
FIGS. 4C and 4D are views similar to FIGS. 4A and 4B, showing needle beam drive and guide systems in accordance with the present invention, with the needle beam being shown in a fabric-engaging position in FIG. 4C and in a non-fabric-engaging position in FIG. 4D;
FIG. 5 is an enlarged end elevation view of the needle beam module shown in FIG. 2;
FIG. 6 is a sectional view, taken along the line 6--6 of FIG. 2; and,
FIG. 7 is an enlarged sectional perspective view, taken along the line 7--7 of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a high speed needle loom having needle beam guide systems in acccordance with the present invention has been illustrated therein generally at 10. The loom 10 includes a left-hand side frame member 12, a right-hand side frame member 14, a top frame member 16 and a bottom frame member 18, which members are fastened to one another to provide a rigid supporting framework for the remaining parts of the loom.
The invention has been illustrated in connection with a duplex type of needle loom in which needling of the non-woven fabric occurs concurrently from both above and below the fabric being processed. However, it will be apparent from the following description that the invention is equally applicable to needle looms in which the non-woven fabric is needled from only one side of the fabric.
In the case of the illustrative embodiment of FIG. 1 the duplex loom includes upper and lower needling plates, shown generally at 20 and 22, respectively. Non-woven fabric to be needled is fed via feed rolls (not shown) that are driven by a feed roll drive motor 24, from a point above the plane of the drawing of FIG. 1, through the plane of the drawing between the upper and lower needling plates 20 and 22, about a draw roll (not shown) that is driven by a draw roll drive motor 26, and is wrapped about a wrap roll (not shown).
The upper needling plate 20 is supported by top frame member 16 via a plurality of screw jack assemblies, four of which are shown at 28, 30, 32 and 34. The screw jack assemblies 28-34 are gang-driven by an upper needling plate drive motor 36 and a drive train that includes a drive shaft 38. Upon rotation of motor 36, worm gears (not shown) at each of the screw jacks 28-34 are rotated by shaft 38. This causes respective lead screws 40, 42, 44 and 46 of screw jack assemblies 28, 30, 32 and 34 to retract into or extend from the various jacks, depending on the direction of rotation of the motor, raising or lowering the upper needling plate 20.
A similar arrangement is provided with respect to the lower needling plate 22. Thus, screw jack assemblies 48, 50, 52 and 54, which are supported by the bottom frame member 18 and in turn support the lower needling plate 22, are gang-driven by a lower needling plate drive motor 56 and an associated drive train that includes a drive shaft 58. Rotation of the drive motor 56 causes worm screws (not shown) associated with each of the screw jacks 48-54 to extend or retract respective lead screws 60, 62, 64 and 66 of the jacks 48, 50, 52 and 54, causing the lower needling plate 22 to raise or lower depending on the direction of rotation of motor 56.
The loom 10 includes a plurality of upper needling modules, shown generally at 70, and a plurality of lower needling modules, shown generally at 72. The upper and lower needling modules 70 and 72 are driven by a needle beam drive motor, shown generally at 74, and drive trains connected thereto which include an upper drive shaft 76 and a lower drive shaft 78.
Referring now to FIGS. 2-5, one of the needling modules which make up the plurality of upper needling modules 70 and lower needling modules 72 has been illustrated therein generally at 80. The needling module 80 includes a needle beam 82 having a plurality of needles 84 projecting therefrom which are adapted to engage the non-woven fabric being processed by the needling loom when the needle beam 82 is reciprocated.
Needle beam 82 is reciprocated by the aforementioned drive motor 74 (FIG. 1) and drive shaft 76, the various sections 76a, 76b of which are coupled together by shaft coupling units 86 (FIGS. 2 and 3). Shaft sections 76a and 76b are supported in respective gear housings 88 and 90 by suitable sets of roller bearings 92a, 92b, and 94a, 94b, respectively. Shaft section 76a carries a spiral beveled drive gear 96 on it which gear, in turn, drives a driven spiral beveled gear 98 that is geared to an eccentric drive shaft 100 so that rotation of drive shaft section 76a causes rotation of the eccentric drive shaft 100. Similarly, drive shaft section 76b carries a spiral bevel drive gear 102 along with it and the gear 102, in turn, drives a second spiral bevel driven gear 104 that is fixed to and rotates a second eccentric drive shaft 106. Shafts 100 and 106 are supported in a housing 101 by respective sets of roller bearings 103a, 103b, 103c and 105a, 105b, 105c.
Eccentric cams 108 and 110 are keyed to the respective eccentric drive shafts 100 and 106. The eccentric cams 108 and 110, in turn, are rotatable in respective bearings 112 and 114 that are carried within openings at corresponding first ends of connecting rods 116 and 118 (FIG. 2) which extend between the cams 108 and 110 and needle beam 82. The other corresponding ends of the connecting rods 116 and 118 are journaled on respective shafts 120 and 122 which, in turn, are supported in respective housings, shown generally at 124 and 126. Housings 124 and 126 are fastened to the needle beam 82 by respective bolts 128 and 130.
Referring more particularly to FIG. 6, wherein the housing 126 has been shown in greater detail, it will be apparent that the shaft 122 is journaled in spaced apart end walls 132 and 134 of housing 126 by means of bearing 136 and 138, respectively. The end walls 132 and 134 are welded or otherwise fastened to side walls 140 and 142 to complete the housing 126. A similar construction is employed in connection with the housing 124, as may be seen in FIG. 2.
Referring to FIGS. 4A, 4B, 4C and 4D at this time, a brief discussion of prior art forms of needle guide systems will be made with reference to FIGS. 4A and 4B before a detailed discussion is made with respect to the needle beam guide system of the present invention, illustrated in FIGS. 4C and 4D. As shown in FIG. 4A, a needle beam 150 having needles 152 thereon is reciprocated by means of a connecting rod 154. The prior art guide system for beam 150 includes a cylindrical guide post 156 which is rigidly fixed to the upper surface of beam 150 and projects upwardly therefrom into and through a guide bushing 158 that is fixed to the undersurface of the needle loom frame 160. Thus, cylindrical bushing 158 constrains the reciprocation of beam 150 to vertical movement by the sliding engagement existing between the bushing 158 and the guide post 156 which reciprocates vertically within the bushing 158.
As shown in FIG. 4B, misalignment occurs between the guide post 156 and the fixed bushing 158 when the densely mounted needles 152 penetrate a non-woven fabric web 159 in connection with the needling operation. During such penetration, upwardly directed forces are generated which are resisted by the needle beam 150. These forces cause the needle beam to deflect slightly between and beyond the mounting positions of the connecting rods 154 so as to cause the needle beam 150 to take a gull-wing-like shape, as shown in exaggerated form in FIG. 4B. Since the conventional guide post 156 is mounted to the needle beam 150 either between the connecting rods 154 or outside of the connecting rods, an angular displacement of the base of the post relative to the vertical direction occurs, due to deflection of the beam under load. This angular displacement, identified by the arrows at 162 in FIG. 4B, occurs due to the fact that the guide post 156 remains perpendicular to the surface of the beam and, consequently, leans toward the connecting rod during deflection of the beam under load. This causes the post 156 to skew within, and bend with respect to, the guide bushing 158, the axis of which remains vertical at all times. The skewing action causes very heavy side loads to be applied to the guide system, creating excessive heat and resulting in the various disadvantages referred to earlier herein.
In accordance with the present invention, and as illustrated in FIGS. 2, 4C, 4D and 5-7, a slide bushing, shown generally at 170, is provided which is pivotally mounted relative to its supporting structure so that the axis of the cylindrical slide opening therein can remain aligned with the axis of a guide post 172 with which it is slidably engaged. In the preferred embodiment of this invention the guide post 172 is fixedly attached to a frame member 174 by a bracket 176 having an adjustable clamp portion 178 which facilitates vertical positioning of the guide post 172 relative to the bracket 176. Frame member 174, in turn, is fixedly carried by the top frame member 16 (FIG. 1) of the needle loom so that each of the guide posts 172 are fixed in space relative to the frame of loom 10.
As shown most clearly in FIGS. 6 and 7, the slide bushings 170 include a slide bushing housing 180 that is mounted on a pivotal shaft 182 having shaft sections 182a and 182b projecting outwardly therefrom. Shaft section 182a is journaled in a sleeve bearing 184 carried by a bracket 186 that is welded or otherwise rigidly fastened to the side wall 142 of the housing 126 to which connecting rod 118 is connected. Shaft section 182b is journaled in a sleeve bearing 188 carried in a bracket 190 that is also welded or otherwise fixedly carried by the sidewall 142. The arrangement is such that the housing 180 is pivotable relative to the brackets 186 and 190.
A slide bearing 192 is positioned .within the slide bushing housing 180 and is held in place therein by means of spaced retainer clips 194 and 196 (FIG. 7) that engage with respective groove 198 and 200 formed within the inner periphery of slide bushing housing 180. The spacing between the retainer clips 194 and 196 is slightly greater than the axial length of the slide bearing 192 so that the bearing is capable of limited axial movement therebetween. In addition, the outer diameter of the slide bearing 192 is slightly less than the inner diameter of the slide bushing housing 180, and spaced apart "O"-rings 202, 204, which are mounted in spaced grooves 206, 208 formed on the inner periphery of the slide bushing housing 180, are employed to resiliently, radially center the outer periphery of the slide bearing 192 relative to the inner periphery of the slide bushing housing 180. The inner diameter of the slide bearing 192 is such as to allow the slide bearing to slidingly move upon the guide post 172 during reciprocating movement of the needle beam when the loom is in operation.
Referring to FIG. 2, the construction of the guide system associated with connecting rod 116 and housing 124 and is essentially the same as that described above in connection with connecting rod 118 and housing 116. Accordingly, corresponding parts in that guide system have been identified with the same numerical designations as those indicated above.
From the foregoing description, it will be seen that the construction employed allows the slide bearing 192 to shift slightly within its slide bushing housing 180 so that side thrusts caused by the deflection of the needle beam under load can be compensated for by compression of the O-rings 202, 204. Moreover, it will be seen that pivotal mounting of the slide bushing housing 180 relative to the upper surface of the needle beam 82 allows the housing and its associated bearing to realign with the vertical when the upper surface becomes deflected under load. A combination of the two features, namely shifting to minimize side thrust and realigning to compensate for the skewing of the center line of the slide bearing relative to the vertical center line of the guide post, greatly reduces the forces on the guide post and on the slide bushing, limiting heat build-up and premature breakdown of lubricant sealant systems. In addition, by mounting the guide bushing on the upper surface of the needle beam and the guide post on the lower surface of the loom frame, rather than vice versa, the bushing is positioned closer to the point of beam deflection, minimizing the horizontal displacement of the center line of the guide post from the centerline of the slide bushing that is otherwise encountered due to the angular relationship between the two centerlines when the needle beam is deflecting due to loading, as shown by the differences in length of the dimensions marked "A" and "B" in FIG. 4B.
While a particular embodiment of this invention has been shown and described, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. As one example thereof, the slide bushing 170 and its associated parts could be pivotally mounted to the undersurface of the frame 174 of the loom while the guide posts 172 could be rigidly fixed to the upper surface of the needle beam. Such an embodiment, although not achieving the full benefits of the preferred embodiment of the invention, provides compensation for the misalignment of the axes of the guide posts and the slide bearing and provides some compensation for the side thrust generated by the misalignment, notwithstanding that the side thrust is greater when the slide bearing is positioned remote from, rather than adjacent to, the needle beam. Other examples of changes and modifications that may be made without departing from this invention in its broader aspect will be readily apparent to those skilled in the art. It is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.
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A needle loom is disclosed. The loom comprises a frame; a needle beam; means, including a drive shaft and crank means carried by the drive shaft and coupled to the needle beam, for reciprocating the needle beam relative to the frame; and, means, including a guide means fixedly carried by the frame and a slide means pivotally carried by the needle beam and slidable relative to the guide means, for guiding the needle beam during its reciprocating movement relative to the frame.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention relates generally to pump control systems, and more particularly, to those pump control systems used to control multiple pumps such as are used in duplex and triplex pumping systems.
[0005] Herein, we use “low-voltage” to mean less than 50 volts. We refer to “line-voltage” as greater than 50 volts, and 120V is used to mean a specific nominal line-voltage that is lower than the line-voltage used to power the pumps. The line voltage used to power the pumps is typically 480 volt, 3-phase or 240 volt 3-phase. The 120V circuits are typically used for functions such as powering low-voltage supplies, starter coils, interposing relays, and the like.
[0006] Commonly, all components of such a system are installed in a single enclosure. Such an arrangement necessitates de-energizing the entire enclosure for service or adjustment of a single component when following safety procedures and regulations. Federal safety regulations require de-energizing enclosures containing voltages of 50 volts and higher except in specific exceptional situations. De-energizing the entire enclosure is problematic in those applications that require operation of at least one of the controlled pumps at any time.
[0007] Another common method used in such pump control systems is to utilize motor control centers that compartmentalize motor controllers in removable subunits. Motor control center subunits typically have the disconnecting device (e.g. circuit breaker) enclosed within the subunit itself; which means the subunit must still be considered energized due to the fact that the disconnecting device and conductors feeding it are still energized and within the enclosure even after the door interlocked handle is switched to the OFF position. Thus, the subunit is not totally de-energized even when the disconnect handle is in the OFF position. In order to completely de-energize a motor control center subunit for service the subunit stabs must be disconnected from the motor control center bus. Safety hazards including arc-flash exist when disconnecting stabs from a live bus. Powering down the motor control center is problematic in applications where operation of at least one motor or other load served by the motor control center system is required during maintenance.
[0008] It would therefore be desirable to design a pump control system that allows one or more of the controlled pumps to remain in operation while components within the system are serviced within a compartment that is totally de-energized.
BRIEF SUMMARY OF THE INVENTION
[0009] A modular pump control panel assembly consisting of multiple compartments arranged so as to allow service of each individual compartment without exposure to line voltages while still maintaining operation of the pumping system. The assembly includes a plurality of motor controller compartments each including a lockable handle operator that that is interlocked with its corresponding compartment door. The handle operators are mechanically connected to remote disconnecting devices (e.g. circuit breakers or the like) via flexible cables or mechanical linkage. A key feature and distinction of this invention is that the disconnecting devices are not located in their corresponding motor controller compartments, even though the handle that operates the disconnecting device is a part of the motor controller compartment and interlocks with the door of same. Thus, when the handle operator is switched to the OFF position, access is granted to the motor controller compartment which in this state now contains no components (i.e. not even the disconnecting device and/or its supply conductors) energized by line voltage. The assembly is constructed of an overall enclosure housing that contains within it a plurality of motor controller compartments, one or more compartments for remote mounted disconnecting devices, and additional separate compartments as required for devices such as low-voltage controllers, power transfer switches, and termination compartments for field wiring connections.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] The Drawings demonstrate one solution for a preferred embodiment of the described invention.
[0011] Displayed in the drawings:
[0012] FIG. 1 is a front elevation view of the modular compartments within an overall enclosure. The doors of the overall enclosure, as well as the modular compartments, are closed in FIG. 1 .
[0013] FIG. 2 is a front elevation view of the modular compartments within an overall enclosure. The termination compartment doors of the overall enclosure, the doors for the motor controller compartments and the plate/door for the breaker compartment are removed in FIG. 2 . The motor controller compartment doors are not shown. The flexible cables linking the door handle operators to the remote disconnects are shown diagrammatically.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The following description makes reference to line voltage, low voltage, and the like. It is appreciated that such terms may refer to a variety of both common voltage ranges and unique voltages depending on context. However, it is appreciated that the present invention is intended for use in typical pumping system control applications and the purpose of the invention is to simplify compliance with safety regulations and procedures while keeping the pumping system in operation during such maintenance. In this context, we refer to voltages below 50 volts as “low voltage” because regulations allow access to energized control panels when only voltages below 50 exist within. We refer herein to the pump motor supply voltage as well as any other associated circuits of 50 volts or higher as “line voltage”. A typical example would consist of a system wherein the pump motors are supplied at 480 volts 3-phase, starter coils and relays and associated with the motor controllers are supplied at 120 volts 1-phase, and control system components such as programmable logic controllers and modems are supplied at 24 volts DC.
[0015] Referring to FIG. 1 a front elevation view of an embodiment of the invention is shown. The overall enclosure contains within it components of a typical duplex pump control system as commonly used applications such as sewage lift stations and water booster pumping stations. Components include motor controllers which may be full-voltage starters, solid-state-reduced-voltage starters, or variable frequency drives.
[0016] The general appearance of the invention is similar to that of a motor control center in that it contains multiple separate compartments, some of which include disconnect operating handles interlocked with the compartment doors. However, there are important and distinct differences between the present invention and existing motor control center designs.
[0017] Buckets for motor control centers are supplied with power via stabs that connect to bus bars. Energized conductors enter the bucket and connect to the supply side of the bucket disconnecting device. The bucket includes a handle operator that interlocks with disconnecting device (e.g. circuit breaker) that is located within the bucket. When the handle is moved to the OFF position a door interlock allows access to the bucket. A hazard exists in that the compartment, which the door interlock has granted access to, contains parts energized at line voltage even when the handle is in the OFF position. Safety procedures and regulations do not allow working within a compartment that contains parts energized at 50 volts or higher other than specific exceptional situations. Removing motor control center buckets and disconnecting the stabs presents new hazards of arc-flash if performed when the bus is energized. De-energizing the motor control center is often undesirable because many load devices may be fed from the motor control center and shutting down all loads can; disrupt the process, cause flooding in the case of a sewage lift station, or cause loss of water pressure in the case of a water booster station.
[0018] The motor controller compartments of the present invention are distinctly different from existing; there are three ways in which they are different that I will expound upon.
[0019] The first distinction is that in the preferred embodiment of my invention the disconnecting device is remotely located, while still operated by the handle operator that is part of the motor controller compartment and interlocked with the motor controller compartment door. This feature eliminates the existence of energized line voltage parts within the compartment when the handle is switched to the OFF position. The incoming power conductors come from the load side of the remote disconnect only; so the supply conductors are de-energized in OFF position as well.
[0020] Secondly, in the preferred embodiment of my invention; there is no use of stabs (e.g. those that are commonly used to connect line voltage for disconnecting devices to bus bars). By not making use of stabs; the risks that are associated with them (e.g. arc-flash between phases when removing the bucket) are no longer present. Also, there is not need to worry about the integrity of the connection between the bus bars and the stabs decaying over time due to connection and disconnection.
[0021] Thirdly; whereas in some cases with motor control centers a person would be exposed to bus bars when the bucket or sub-panel was removed, in the preferred embodiment of my invention; behind the sub-panel is the back of the enclosure for which the person is servicing. In the preferred embodiment of my invention; the interior of each compartment is isolated from that of any of the other compartments within the system.
[0022] Another very common conventional design for pump control panels used in smaller sewage lift stations and water booster stations is to install all motor controllers, breakers, transformers, relays, logic controllers, telemetry equipment, and other devices within a single enclosure. This design makes adherence to electrical safety regulations extremely inconvenient in that one would need to de-energize the entire control panel for many common maintenance tasks. As it is often undesirable to shut down the pumping process, and as it is inconvenient to follow all applicable safety regulations in this case, personnel may tend to ignore regulations and access the panel energized when performing common maintenance tasks.
[0023] It is a purpose of my invention to simplify compliance with safety regulations, thereby encouraging compliance.
[0024] Referring again to FIG. 1 , assume it is necessary to perform maintenance to the motor controller serving pump # 1 of a duplex system. The technician switches the pump # 1 motor controller compartment handle to the OFF position. Following standard safety procedures the technician then verifies that the pump # 1 compartment is de-energized and locks out and tags out the handle. At this point he can perform his work within the compartment without concern of violating regulations as the compartment he is working in is completely de-energized of line voltage. While performing his work the pumping control system continues to operate automatically using pump # 2 . This scenario is preferable to de-energizing the entire system as would be required with the commonly used single panel design described above. It is also preferable to working in a motor control center bucket that contains live line side lugs and supply conductors even when the disconnect handle is locked in the OFF position.
[0025] Referring to FIG. 2 , we see an internal representation of the disconnecting devices located in a compartment separate from the motor controller compartments. These disconnecting devices may also require maintenance. In my preferred embodiment the compartment(s) housing these disconnecting devices can be de-energized without interrupting the pumping process. An alternate power source can be provided. This alternate source can be the same utility power providing normal power, but provided from a separate breaker or fused switch and connected to the bypass power terminals. A bypass power connector being fed from the bypass power terminals can be plugged into either of the motor controller compartments;
[0026] One of the motor controller compartments would be de-energized by putting the disconnect handle in the OFF position.
[0027] The bypass power plug would then replace the normal power plug.
[0028] The normal supply power serving the control panel would then be de-energized and an alternate supply energized as the bypass feed (in this state; the disconnecting device compartment as well as the line voltage compartment are totally de-energized for maintenance, the pumping system continues to operate using the pump(s) supplied with bypass power).
[0029] Referring to FIG. 1 , in my preferred embodiment a separate line voltage compartment is provided for incoming power provisions and equipment such as automatic transfer switch, surge protection, and the like. This compartment provides power to the disconnecting devices in the disconnecting device compartment(s) and is served by connection lugs in the termination compartments. This line voltage compartment may be bypassed as described above for maintenance.
[0030] Referring to FIG. 1 , in my preferred embodiment a separate low voltage compartment is provided for automatic control devices such as programmable logic controllers, telemetry equipment, and the like. All devices and wiring in this compartment should be powered at less than 50 volts so that the automatic controls can be serviced while energized when necessary. A DC battery backup system located within the low voltage compartment can be used to power the automatic controls, telemetry, and field devices (e.g. pressure or level sensors) so that automatic operation and monitoring are available even when normal power is de-energized and a pump is being operated on bypass power.
[0031] Referring to FIG. 1 , in my preferred embodiment a separate 120 volt compartment is provided for devices such as DC power supplies and circuit breakers for 120 VAC loads. The DC supplies are located herein rather than in the low voltage compartment as the DC supplies typically are energized at 120 VAC on their input terminal Placing the DC supplies external to the low voltage compartment allows the low voltage compartment to be serviced in an energized state.
[0032] Referring to FIG. 1 , in my preferred embodiment the various compartments described previously are assembled into an overall enclosure. The overall enclosure provides areas for field terminations and wire routing. It is preferred that interconnections between the various compartments enter each compartment via “thru-wall” terminals and plugs as shown in FIG. 2 such that the integrity of separation between compartments is not compromised by openings.
[0033] To manufacture my invention:
[0034] The manufacturing entity would mount and wire the appropriate devices for each of the following aspects of pumping control within their respective compartments, while following the necessary guidelines that I have previously laid out within this document (e.g. mounting motor controller disconnects in separate compartments from the motor controllers which they feed so that line voltage is removed entirely from the motor controller compartment when the disconnect and its respective handle are in the OFF position, mounting power-supplies that require a supply voltage greater than 50 volts in a separate compartment from the controls which they supply power to, and the like).
Motor Controllers Disconnecting Devices AUTO Logic Controls (e.g. PLC(s), relays, and the like) Other Devices, as necessary (e.g. transfer switches, circuit breakers, surge protection devices, and the like)
[0039] Components and methods such as; through-wall terminals, interlocking handles, interposing relays, indicators or operators with appropriate gaskets, and the like should be used so that the integrity of isolating the compartments, from each other and a person standing in front of the system, remains in tact.
[0040] The compartments should be arranged in such a way to allow for operation and interaction of the complete system in the mode that I have described within this document.
[0041] In the preferred embodiment of my invention; all of the individual compartments would be arranged and mounted within an overall enclosure.
[0042] When manufacturing in volume, a complete single enclosure which includes all of the same separation by barriers and various doors and covers could be made to reduce costs and materials used for a specific configuration.
[0043] In smaller volumes use of separate enclosures installed within an overall housing is more flexible, in that various options can be pre-assembled in compartment enclosures and then assembled in different combinations for project specific requirements. For example, a triplex system could be generally the same as the duplex system shown in the figures except that three smaller motor controller compartments would be installed in the same space that is used for two motor control compartments as depicted in FIG. 1 and FIG. 2 .
[0044] I have herein described the preferred embodiment of the present invention in one form that would be useful for a duplex pumping control system. The specific arrangement would necessarily vary depending on the number of pumps, project specific requirements, and desired optional features. It is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
DRAWINGS
[0045] Drawings are contained in file Drawings.pdf
OATH OR DECLARATION
[0046] Declaration is contained within file Declaration.pdf
SEQUENCE LISTING
[0047] Not Applicable
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A modular pump control panel assembly consisting of multiple compartments arranged so as to allow service of each individual compartment without exposure to line voltages while still maintaining operation of the pumping system. The assembly includes a plurality of motor controller compartments each including a lockable handle operator that that is interlocked with its corresponding compartment door. The handle operators are mechanically connected to remote disconnecting devices via flexible cables or mechanical linkage. A key feature/distinction of this invention is that the disconnecting devices are not located in their corresponding motor controller compartments, so that when the handle operator is switched to the OFF position there are no components (e.g. disconnecting device and/or its supply conductors) within the motor controller compartment that remains energized by line voltage.
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FIELD OF THE INVENTION
This invention pertains to airbag canisters. More particularly, this invention pertains to airbag canisters or housings that are selectively heat treated to enhance ductility and toughness, and a method for making such canisters.
BACKGROUND OF THE INVENTION
Airbags or supplemental restraint systems are an important safety feature in many of today's vehicles. Airbag deployment technology uses controlled combustion or an “explosion” to rapidly expand or deploy the airbag upon sensing an impact with another vehicle. This controlled explosion is contained within a canister or housing so that the rapidly expanding gases can be directed into the airbag for inflation.
Containing the controlled explosion of these chemicals is necessary for proper deployment of the airbag. The canister in which the chemicals are contained must be configured and manufactured to assure complete, controlled and predictable combustion within certain given parameters and requirements. One of these requirements is maintaining the structural integrity of the canister. That is, the canister must be configured and fabricated such that it maintains its integrity through the combustion process and subsequent airbag deployment. In testing of these canisters, in the event that a canister does rupture or yield, such rupturing or yielding must be predictable.
One currently used combustion chamber includes a substantially tubular member having two open ends. The chamber is formed from rolled and seal-welded plate stock, or is drawn as a seamless tube, such as that used for common piping. In this arrangement, however, welds are needed to seam-weld the rolled plate and/or seal-weld a plate to an open end of the tube. These welds are highly critical and as such require considerable labor and in certain instances testing to assure weld integrity throughout the combustion process and airbag deployment. It has been observed that these welds can crack or fail, thus, compromising the integrity of the canister, and possibly the operation of the airbag.
The canisters are tested to assure that they retain their structural integrity during airbag deployment. One such test is a burst test. This is a destructive-type test in which a canister is subjected to internal pressures significantly higher than those expected during normal operational use, i.e., airbag deployment. In this test, the canister is subjected to increasing internal pressures until failure.
In reviewing the burst test results and studying the test canister specimens from these tests, it has been found that failure occurs through ductile failure, brittle failure, and sometimes a combination of these two phenomena. It has been observed that in ductile fracture or failure an outturned rupture exemplified by an opened bulge (such as would be exhibited by a bursting bubble) occurs. This rupture is localized within a subject area. In a brittle fracture, on the other hand, through-wall longitudinal cracks along the length of the canister are exhibited which are indicative of a brittle zone in the material.
At times, a combination of these two failure mode can be observed. For example, a failure may occur due to ductile failure in which case a rupture or opened bulge is found. In those instances where a combination of the failure mechanisms is found, brittle cracks can propagate from the ductile, ruptured area.
Accordingly, there exists a need for an airbag canister having a high degree of structural integrity with a reduced number of welds. Preferably, such a canister is formed from relatively common carbon steel materials. Most preferably, such a canister is fabricated in a method using efficient and cost-effective parts and processes for manufacturing the canister.
SUMMARY OF THE INVENTION
A selectively heat treated canister for use in a vehicle airbag deployment system is configured to contain combustion materials and to contain gases produced from the combustion process. The canister includes a tubular body having a length and a longitudinal axis. The body is formed as at least two drawn sections. Preferably, the canister body is formed from a flat stock material that is drawn. Each prior section is drawn one more time than a successive adjacent section.
The canister defines a closed end and an open end. The closed end is at a least drawn section and the open end is at a most drawn section. The canister defines a heat treated region and is selectively heat treated at at least one transition zone between adjacent drawn sections. The combination of drawing and heat treating increases the toughness and ductility of the canister to reduce or eliminate the potential for unwanted failure modes in testing.
In a current embodiment, the canister body is formed as three drawn sections and defines a first worked zone that is drawn three times, a second worked zone that is drawn twice and a third worked zone that is drawn once. The heat treated region overlies a transition region between the second worked zone and the third worked zone.
Governmental specifications establish limitations for the material used for airbag canisters. One such limitation is that the canister material can have no more that 0.15 percent carbon. To this end, the canister can be formed from a low carbon steel material, such as AISI 1006 to 1010. The canister can also be formed from a high strength low alloy steel such as HSLA 50.
A method for making a combustion containing canister for use in an airbag deployment system includes the steps of providing a steel plate and drawing the plate. In a first drawing step, a first portion of the plate is drawn into a die in a first work step to define a first worked zone. The method further includes drawing, in a second drawing step, a second portion of the plate into the die in a second work step to define a second worked zone and to further draw the first worked zone.
Optionally, a third drawing step can be carried out in which a third portion of the plate is drawn into the die in a third work step to define a third worked zone, to further draw the second worked zone and the first worked zone, to define a canister body. This process can be carried out to form a canister body having a plurality of worked zones. A current method includes a first drawing step to define a first worked zone, a second drawing step to define a second worked zone and a third drawing step to define a third worked.
The method includes heat treating a portion of the canister body after working. Preferably, that portion of the canister body that is heat treated extends across a transition between worked zones. In a present method, the heat-treating step is carried out by induction heating, and the canister body is heat treated at a transition between the third worked zone and the second worked zone.
During burst testing, it was found that fracture of the canisters began in the least work hardened or lowest tensile strength zone and would propagate toward the end of the canister (i.e., through the work hardened zones). Heat treating at a transition zone between worked zones creates a region that absorbs the energy of the propagating crack that began in the weaker zone and stops crack propagation.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a cross-sectional view of an exemplary airbag canister embodying the principles of the present invention;
FIG. 2 is a side view of the airbag canister, illustrating the various worked zones and the heat treated region of the canister;
FIG. 3 is a graphical representation showing the burst pressure in pounds per square inch (psi) (shown along the ordinate), as a function of the length along the canister, from where the failure propagated (shown along the abscissa), and further indicating the induction heat location along that length and the zone in which failure occurred and the failure mechanism exhibited;
FIG. 4 is a graphical representation of the material strength shown along the ordinate as a function of the percent elongation (shown along the abscissa), and further indicating the worked zones or regions (w 1 , w 2 and w 3 ) of the canister, prior to heat treatment (shown along the ordinate); and
FIGS. 5 a - 5 d illustrate the steps carried out in drawing or working the canister body to define the worked zones.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.
Referring now to the figures and in particular to FIG. 1 there is shown an exemplary airbag canister 10 that is used in an automobile airbag deployment system or assembly. The canister 10 includes a main body portion 12 having a plurality of step wise drawn regions. An end 14 of the canister is open, while an opposing end 16 of the canister is closed and is formed integral with the canister body 12 . That is, the canister 10 is formed as an integral or unitary element. The closed end 16 can further include an indent or dimple 18 , in which a bore 20 can be centrally formed. In an anticipated use, the bore 20 can receive a sensor or an ignition device (not shown) for the airbag assembly.
At the open end 14 , the end walls, indicated at 22 , can be inwardly directed or formed to define a canister throat 24 . The canister body 12 has a length L and defines a longitudinal axis A about which it is symmetrical. The throat wall end 26 can be finished or machined so that it is substantially perpendicular to the longitudinal axis A.
In a present embodiment, the canister 10 is formed by drawing, and has three distinct worked zones. These zones are shown graphically in FIG. 2 as w 1 , w 2 , and w 3 . As will be discussed below, the third worked zone w 3 is the least worked of the three zones (i.e., worked once), while the first worked zone w 1 is the most worked of the zones (e.g., worked three times).
Referring briefly to FIGS. 5 a-d, in forming the canister 10 , a plate P is placed over a die (not shown) having a circular opening. A press (not shown) contacts and presses the plate P into the die in a first work step, as illustrated in FIG. 5 b. The press contacts the plate P at a location that ultimately becomes the closed end 16 of the canister 10 . This is the first working of the first worked zone w 1 .
The press then contacts the closed end 16 of the canister 10 a second time, further urging it into the die, thus forming the second worked zone w 2 , as illustrated in FIG. 5 c. At this point in the process, the first worked zone w 1 has been worked or drawn twice, the second worked zone w 2 has been worked or drawn once and the third worked zone has not been drawn.
As seen in FIG. 5 d, to form the third worked zone, the press contacts the closed end 16 of the canister 10 a third time further urging it into the die. This works or draws the third work zone w 3 once, works the second work zone w 2 a second time and works the first work zone w 1 a third time.
The open end 14 of the canister is, as will be recognized by those skilled in the art, at the farthest or most distant portion from the closed end 16 of the canister 10 , at an end of the first worked zone w 1 . The closed end 16 of the canister is not worked. The working of the steel is carried out at about room temperature.
Subsequent to working, and thus forming the canister body 12 , a portion of the canister, as indicated at 28 , is selectively heat treated. Heat treating is performed on the canister at about the worked zone 2 /worked zone 3 transition. The distance along the canister 10 at which heat treating is carried out is sufficiently large to assure that the worked zone 2 /worked zone 3 (w 2 /w 3 ) transition zone is completely encompassed by the heat treated area 28 .
In a preferred method, heat treating is carried out using an induction heating process in which the heating element and/or the canister is rotated so as to assure that heat treatment is circumferentially evenly carried out at about the heat treating zone 28 . In a present embodiment of the canister 10 and a present method for making the canister 10 , heat treating is carried out by heating the canister body 12 at the transition zone 28 to a temperature sufficient to recrystallize the elongated grain structure. For example, when an AISI 1010 steel is used, a temperature of at least about 1100° F. is used for heat treating the canister.
As will be recognized by those skilled in the art, the work hardening or drawing of the body 12 elongates the grain structure. While this does, in fact, increase the hardness of the material within the drawn zone, by doing so it elongates the grain structure of the material in the drawn direction and shortens the grain structure in a direction transverse to the elongated direction. However, this work hardening results in a decrease in the ductility of the material in the work hardened region.
To this end, heat treating the material causes recrystallization of the microstructure (in the elongated direction) and likewise widens the grain structure (transverse to the direction in which it was elongated) in the heat treated region. Thus, it has been found that heat treating increases the toughness and ductility in the heat treated area. Heat treatment is carried out at a temperature that is sufficient to recrystallize the grain structure, and is carried out for a period of time sufficient to recrystallize the grain structure throughout the thickness of the material, i.e., through the wall of the canister.
It has also been observed that canisters that have been drawn and have not been heat treated are susceptible to a brittle failure mechanism, which failure mechanism is unacceptable in airbag manufacture. In a brittle fracture failure, the canister fractures from the initial point of yield up to and through the canister wall at the open end 14 of the canister 10 . In contrast, a ductile fracture mechanism, which is acceptable in airbag canister applications, is manifested by yielding of the canister in a localized area that does not extend to and through the canister wall at the open end 14 of the canister 10 . It has been observed that canisters 10 that are made in accordance with the present invention, which have been drawn in a stepped manner (e.g., w 1 , w 2 , w 3 ), and which have been heat treated in the transition zone 28 between the second and third worked zones w 2 /w 3 are susceptible substantially only to ductile fracture failure under the required pressure conditions.
In a current embodiment of the canister 10 , one material that that has been found to be acceptable for manufacture of the canister 10 is an AISI 1006-1010. It has also been found that a high strength low alloy material (e.g., HSLA 50) which has a yield strength of about 50 ksi is also suitable for the canister 10 material. In a preferred method, the canisters are formed from a steel having an AISI 1010 designation and are heat treated for a period of about 25 seconds with a 5 kw power source, and are heated to a temperature of at least about 1100° F. When an HSLA 50 steel is used, a temperature of at least about 1150° F. is used for heat treating the canister.
The following examples illustrate various characteristics of the heat-treated airbag canister.
EXAMPLE 1
A sample of the canisters made from HSLA 50 were examined to determine the burst pressure and failure mode at various induction heat-treated locations, measured as distances along the length of the canister. The results of these tests are shown graphically in FIG. 3, in which the burst pressure is plotted against the induction heat location from the top of the canister in inches. As can be seen from the figure, within the ductile zone, that is up to about 2 inches from the closed end of the canister, a burst pressure of about 18,000 pounds per square inch (psi) was exhibited. Within the brittle zone, at 2½ inches from the closed end of the canister, the burst pressure exceeded 18,500 psi. This test was carried out at a temperature of −40° F. and at room temperature (about 72° F.).
EXAMPLE 2
Two groups of canisters were subjected to burst tests in order to compare the burst pressure of various samples. Referring first to Table 1, samples 1-2 were not heat treated. Samples 3-11 were heat treated for the time (duration) shown in the column entitled “Induction Time.” The remaining columns, namely, induction heater power, burst pressure test temperature, burst pressure and failure mode are straight-forward and will be readily understood by those skilled in the art. The location column indicates the failure or crack initiation location observed following testing. Tables 1 and 2, below, illustrate the results of these tests for 6 inch samples and 9 inch samples, respectively.
TABLE 1
Burst Pressure Tests for Six Inch Canisters, STEEL HSLA50
Heat Treated and Non-Heat Treated
Induction
Sample
Time
Temperature
Burst
Location
No.
(sec.)
(° F.)
(psi)
Failure
(in. from top)
1.
As-Is
Room
17927
Brittle
—
2.
As-Is
−40
18410
Brittle
—
3.
23
Room
16621
Ductile
1.5
4.
23
Room
16660
Ductile
1.5
5.
23
−40
16875
Ductile
1.5
6.
23
−40
17411
Ductile
1.5
7.
26
−40
15886
Ductile
1.5
8.
25
−40
16481
Ductile
1.5
9.
25
−40
18576
Brittle
2.5
10.
25
−40
17967
Ductile
1 ⅞
TABLE 2
Burst Pressure Tests for Nine Inch Canisters, STEEL HSLA50
Heat Treated and Non-Heat Treated
Induction
Sample
Time
Temperature
Burst
Location
No.
(sec.)
(° F.)
(psi)
Failure
(in. from top)
11.
As-Is
Room
17198
Brittle
—
12.
25
Room
15954
Ductile
2
13.
25
Room
15963
Ductile
2.1
14.
25
Room
17890
Ductile
2.1
15.
25
−40
14876
Ductile
1.5
16.
25
−40
17175
Ductile
2.1
17.
25
−40
16996
Ductile
2.1
It is first noted from the results that heat treating the canisters 10 shifts the failure mechanism from brittle fracture or failure to ductile failure. As set forth above, ductile failure is manifested by a localized rupturing of the canister, vis-à-vis brittle failure which results in a through open end-wall 26 split of the canister 10 . Thus, heat treating provides a ductile mode of failure during burst testing. It will also be recognized by those skilled in the art that the heat treated region prevented or stopped propagation of the failure beyond the transition zone, thus limiting failure to a localized region.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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A selectively heat treated canister for use in a vehicle airbag deployment system is configured to contain combustion materials and to contain gases produced from the combustion thereof. The canister includes a tubular body having a length and a longitudinal axis. The body is formed as at least two drawn sections. Each prior section is drawn one more time than a successive adjacent section. The canister defines a closed end and an open end. The closed end is at a least drawn section and the open end is at a most drawn section. The canister defines a heat treated region and is selectively heat treated at at least one transition zone between adjacent drawn sections to reduce crack propagation observed during testing. A method for making the canister is also disclosed.
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This application is a continuation-in-part of U.S. patent application Ser. No. 11/202,188 filed on Aug. 12, 2005, which claims priority from U.S. Patent Application No. 60/601,183 filed on Aug. 13, 2004.
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for remotely reading an identifier on an object.
BACKGROUND OF THE INVENTION
Items produced in a manufacturing environment will typically be stored in a warehouse for shipping at a later date. A shipping warehouse will typically house a plurality of products, which are made by differing processes or have different characteristics. This collection of warehouse items may be referred to as the ‘field’. The field can be substantially large and therefore may be organized into a set of defined locations resembling a ‘grid’. The warehouse items are placed at appropriate locations within the grid and these locations are recorded, creating a mapping of the items for subsequent rearrangement or retrieval. A shipping order will typically comprise a combination of dissimilar items from this field requiring this combination of items to be located and collected to complete the shipping order. This shipping order is sometimes referred to as a shipping manifest or lift ticket. Further to gathering items for a shipping order, it may be necessary or beneficial to rearrange or move around the items in the field to optimize floor space or to enable a more efficient arrangement of the items.
When the items manufactured are of substantial dimension and weight, it is typically necessary to retrieve the items from the field using an overhead crane or similar device capable of lifting and transporting items of such dimension and weight. The use of an overhead crane requires the operator of the crane to either be placed at a remote location relative to the field (in the cab of a crane for example) or to operate the crane with a remote control device at field level. When the operator is at a remote distance, the operator may be unable to distinguish between items in the field that are required for a given shipping order. This situation is of particular concern where items are of similar shape but different characteristics, such as in the steel industry where coils of stock that are produced with differing specifications appear similar, especially when viewed from a distance. If the operator uses a remote control device to operate the crane, navigating the field while moving the crane, and reading and scanning the items becomes quite cumbersome for one person. Furthermore, the use of one person at the field level to control the crane, identify the items of interest and scan the item becomes cumbersome due the need for multiple devices to both control the crane and scan the item.
If the crane operator is remotely located relative to the field, a second individual is required to identify the existence and position of the desired items at the field level, to scan the desired items and communicate this information to the operator. The communication between the two individuals is required to identify the item of interest for rearrangement or shipping purposes.
The use of two individuals to gather items in a shipping order tends to be both inefficient and labour intensive given the task to be completed. In the steel industry where the items in the field are of substantial size and weight, the individual assigned to track the appropriate items at the field level would find the method of scanning to be not only time consuming but also dangerous. The inadvertent movement of large items on the field poses a threat to the safety of the individual at the field level and the large area of the field does not lend itself to an efficient method for identifying the desired items in the shipping order.
In the steel industry where the items in the field are large coils, typically the individual at the field level manually scans a barcode found on a tag affixed to the coil. This introduces a possibility for human error. The human error can lead to the processing of incorrect coils, which could possibly generate an incorrect shipment to the customer. Further to the time-related inefficiencies and inherent safety risk, the use of a field level individual requires additional floor space for the above-mentioned navigation of the field. By eliminating the use of a floor operator, less floor space would be required. This is due to a reduction in the required size of the lane ways between adjacent coils. Space is then only required to accommodate the jaws of the crane's picker. This requires an apparatus capable of viewing the field from a distance.
To remotely view labels and barcodes, it has been known to use a camera mounted in a fixed position whereby movement of an item into the field-of-view of the camera allows for remote viewing of a label. This method however requires the position of the labels to be known and the correct item to have been picked by the crane in advance of the camera scan.
Another method of reading labels and barcodes remotely involves a moveable camera capable of tilting, panning and zooming to focus on a desired label or barcode. This method however, requires additional operations to be manually executed by the operator of the crane to identify not only the item of interest but also to correctly centre and zoom in on the label for reading. These additional operator interactions impose an additional opportunity for human error.
It is therefore an object of the present invention to provide a method and apparatus to obviate or mitigate the above disadvantages.
SUMMARY OF THE INVENTION
In general terms, one aspect of the present invention provides a method for remotely scanning objects including the steps of using an imaging system to display an image of the objects on an interface, receiving a location input related to an identification tag which is attached to a desired object based on a location in the image, using the location input to orient the imaging system towards the identification tag, magnifying the identification tag, analysing the image using an array of two-dimensional sensors to determine the deviation of the tag within the image with respect to a preferred position, aligning the tag by adjusting the orientation; and reading information identifying characteristics of the desired object provided by the identification tag.
In another aspect, the present invention provides a system for remotely scanning objects comprising an imaging system positioned remotely from the objects and arranged to image the objects. The imaging system has an adjustable lens for magnifying the image. The system also comprises an interface for displaying an image of the objects and is adapted for receiving a location input for an identification tag attached to a desired object based on a location in the image. The system also comprises a processor connected to the imaging system and the interface. The processor uses the location input to orient the imaging system towards the tag, commands the adjustable lens to magnify the tag, analyses the image using an array of two dimensional sensors to determine the deviation of the tag within the image with respect to a preferred position, aligns the tag by adjusting the orientation of the imaging system, and reads information identifying characteristics of the desired object provided by the tag.
In yet another aspect, the present invention provides a method for aligning a tag in an image, the tag being affixed to an object and having indicia thereon. The method has the steps of obtaining an image of the object having at least a portion of the tag visible in the image; arranging an array of two-dimensional sensors on the image; identifying markings in each of the sensors, the at least one marking indicative of the presence of a particular feature of the tag; computing an average position of the markings to determine a deviation of the average position from a preferred position; and aligning the tag in the image according to the deviation.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described by way of example only with reference to the appended drawings wherein:
FIG. 1 is a schematic representation of a remote crane barcode scanning system.
FIG. 2 is a schematic representation of a scanning camera.
FIG. 3 is a view of the operator control interface within a crane cab.
FIG. 4 is an enlarged view of the touchscreen transmitting an image of the field to the operator via the camera of FIG. 2 .
FIG. 5 a shows an inventory tag.
FIG. 5 b is a representative schematic of the items identified by the camera system during an image analysis procedure.
FIG. 6 is a schematic representation of the system.
FIG. 7 is a flow chart representing one embodiment of the field scanning process.
FIG. 8 is an alternative embodiment of the remote crane barcode scanning system of FIG. 1 utilising two cameras.
FIGS. 9 a - 9 d are diagrams pictorially showing steps in a tag alignment procedure.
FIG. 10 is a flowchart illustrating the steps performed in the tag alignment procedure of FIG. 9 .
FIG. 11 is a flowchart illustrating steps that continue from the flowchart of FIG. 10 .
FIG. 12 is a diagram showing a misaligned barcode using the tag alignment procedure in FIG. 9 .
FIG. 13 is a diagram showing yet another tag alignment procedure.
FIG. 14 is a screen shot of an embodiment of the operator interface shown in FIG. 3 incorporating diagnostic features.
FIG. 15 is a screen shot of the embodiment of FIG. 14 showing a laser rangefinder failure.
FIG. 16 is a screen shot of the embodiment of FIG. 14 showing a camera connection failure.
FIG. 17 is a screen shot of a help menu.
FIG. 18 is a screen shot of a graphical help manual.
FIG. 19 is a perspective view showing an arrangement for the laser rangefinder system of FIG. 1 .
FIG. 20 is a perspective view of the underside of the trolley of FIG. 1 incorporating an illumination system.
FIG. 21 is a screen shot of an advanced options menu.
DETAILED DESCRIPTION OF THE INVENTION
Referring therefore to FIG. 1 , an overhead crane system 10 is positioned above a field of inventory 20 , the inventory in this embodiment being coils 22 of steel varying in specification. The coils 22 are initially placed in the field 20 and the respective positions of the coils 22 in the field 20 recorded using a range finder system 13 or other means. Each position may then be correlated to its respective coil 22 using the system 10 or other suitable methods. The correlation of position to coil 22 enables an operator of the system 10 to at a later time target a particular area of the field in order to locate and scan the coil 22 to determine if it remains at its recorded position.
The overhead crane system 10 includes a trolley 12 mounted upon a bridge 26 and has a communication connection to an operator cab 18 , preferably over a festoon cable to accommodate movement of the trolley 12 relative to the cab 18 . The cab 18 is situated in a fixed position at one end of the bridge 26 . An inventory control system 24 includes location coordinates and inventory information, and also has a communication connection with the operator cab 18 . The trolley 12 includes a set of motors 28 to facilitate translation of the trolley 12 along the bridge 26 . Typically the bridge 26 is mounted on rails 25 transverse to the bridge 26 allowing the bridge 26 to translate fore and aft along the rails 25 .
Translation of the bridge 26 and the trolley 12 in the directions indicated allows the trolley 12 to access objects located anywhere in the field 20 . The trolley 12 furthermore includes a picker 16 for vertically hoisting coils 22 from the field 20 , a camera system 14 , and the range finder system 13 having separate range finders for locating the trolley's position along each axis of the field 20 .
In one arrangement shown in FIG. 19 , a first range finder 13 a is mounted on the bridge 26 and is aligned in the y-direction with a first reflection plate 301 . The reflection plate 301 is mounted on a wall 300 parallel to the length of the bridge 26 . A second range finder 13 b is mounted at one end of the bridge 26 and opposite the trolley 12 such that it will remain fixed in the y-direction irrespective of the position of the bridge 26 . The range finder 13 b is aligned in the x-direction with a second reflection plate 306 that is mounted to the trolley 12 and that is parallel to a wall 304 which is in turn perpendicular to the wall 300 . It will be appreciated that any arrangement can be used that is capable of determining both x and y coordinates.
The range finder 13 a transmits a laser beam 302 that reflects off of the reflection plate 301 and returns to the range finder 13 a in order to measure the current x-coordinate for the bridge 26 and trolley 12 . The second range finder 13 b transmits a second laser beam 306 that reflects off of the reflection plate 305 and returns to the range finder 13 b in order to measure the current y-coordinate for the trolley 12 . The range finders 13 a , 13 b are connected to the system 10 and provide an ongoing measurement of the position of the trolley 12 in the field 20 for correlating a particular coil 22 to a particular location as explained in further detail below.
The camera system 14 can be seen in greater detail when referring to FIG. 2 . The camera system's components are housed within a casing 36 and this casing 36 is mounted to the underside of the trolley 12 . A zoom lens 32 of a camera 34 protrudes beyond the lower surface of the casing 36 , which is partially open and covered by a transparent acrylic enclosure 30 . The camera 34 is preferably a “smart” camera, which is a camera having a microprocessor capable of processing image data. This functionality enables the camera 34 to process information related to the coils 22 , that are acquired in an image.
The processing may also be done remotely from the camera 34 in a separate processor. The acrylic enclosure 30 allows movement of the zoom lens 32 within its volume and is transparent, allowing the lens 32 to capture images. The camera 34 is controlled by a pan/tilt mechanism 40 . The pan/tilt mechanism 40 can orient the camera 34 using various pan and tilt operations in order to point the camera 34 towards a desired area of the field 20 . A motor 38 is incorporated within the pan/tilt mechanism 40 and controls its movements. The motor 38 is controlled by an electronic controller 33 which has a communication connection to the smart camera 34 or other system control computer (not shown).
Referring now to FIG. 20 , the lens 32 of the camera system 32 has a field of view 310 that when properly focussed can image a barcode 60 on a coil 22 . In a shipping or storage facility, often regions of the facility have poor or uncontrolled ambient light and in some cases having no ambient light is preferable. In order to most effectively capture an image of the barcode 60 , an adequate amount of ambient light should be provided at least in the region of the camera lens' field of view 310 . As seen in FIG. 20 , a localized illuminated region 312 is provided by an illumination system 308 mounted to the underside of the trolley 12 , whereby, as the camera system 14 moves, so does the illumination system 308 . It will be appreciated that the light can be arranged in any suitable configuration with respect to the camera system 32 and should not be limited to only the configuration shown in FIG. 20 .
FIG. 20 shows the illumination system in isolation. The system 308 comprises four linear light arrays. Preferably, a pair of red LED linear lights 314 , 315 sandwich a pair of infrared LED linear lights 316 , 317 . The red LEDs 314 , 315 are arranged above the picker 16 and aimed at the underlying coil 22 to illuminate that coil 22 and the surrounding floor of the field 20 at all times. The infrared LED lights 316 , 317 are preferably synchronized with the camera's exposure time during readings and are normally off when not scanning to prolong their lifespan. Therefore, it can be seen that even in low or non-existent ambient light conditions, the region directly below the camera system 14 is provided with sufficient illumination to enable a useful image to be captured. It will be appreciated that any colour of LED can be used and should not be limited to red. Suitable linear lights are those produced by Spectrum Illumination™.
The interface located within the operator cab 18 is shown in FIG. 3 . The cab 18 contains a computer interface 50 which includes a touchscreen 54 . A control console 52 allows the operator to control manually, the movements of the trolley 12 .
To obtain maximum control and flexibility, an industrial PC can be used for the computer interface 50 that runs a visual basic (VB) API 400 (see FIG. 14 ). The industrial PC integrates, via serial and Ethernet ports, all the communication elements and displays the camera feeds. A typical industrial PC has five serial ports and can be made responsible for the touch screen input, the x and y laser range finder inputs, the barcode output, and the location output. The Ethernet port can be connected to the local camera network for the camera system 14 that is used to display the camera feeds while sending and receiving information from the cameras. The VB interface can continuously calculate and update the location and can output the barcode and location information to the inventory system 24 as described in greater detail below. The VB interface can also be used to automatically control the camera zoom and focus algorithms to accommodate changing floor levels. The flexibility that is inherent in using a platform such as VB advanced lens control can be implemented to control the iris, focus and zoom levels to accommodate abnormally sized barcode tags and for calibrating a new system 10 .
Making reference now to FIG. 4 , the touchscreen 54 displays the images acquired by the camera system 14 . These images show objects in the field 20 and in this particular example are coils of steel 22 . The coils 22 are of differing specifications, and information pertaining to the coil 22 is stored on a tag 60 . The tags 60 are intended to be affixed to the upward facing surfaces of the coils 22 typically in an unspecified manner and therefore do not appear at consistent locations on the upward facing surfaces of the coils 22 or in consistent orientations thereon. The information found on the tag 60 is unreadable from the distance that the operator is located and therefore must be magnified by the camera system 14 . A tag 60 is shown in FIG. 5 a . The tag 60 includes a barcode 64 , a numerical code 66 and a set of alignment markers 62 . An alignment marker 62 is located in the proximity of each of the four corners of the barcode 64 . One alignment marker 62 a is dissimilar to the other alignment markers 62 b , 62 c , 62 d . The dissimilar alignment marker 62 a is used by the camera system 14 to determine the orientation of the tag 60 in the image. The orientation of the tag 60 allows the camera system 14 to choose the appropriate direction to perform the barcode scan.
In FIG. 5 a , the dissimilar marker 62 a is located in the top-left portion of the image with respect to the other markers 62 b , 62 c , 62 d . The dissimilar marker 62 a includes a triangular notch which points towards the centre of the barcode 64 . The remaining three markers are triangular in shape and are rotated 90° with respect to each other such that they each point towards the centre of the barcode 64 . The alignment markers 62 are located at substantially equal distances from the centre of the barcode 64 . These distances are known proportions of the tag's size (for instance a proportion of the width). These proportions and the tag size itself are programmed into the camera system 14 . The camera system 14 can use the width of the tag 60 seen in the image to establish scale. Distances can be measured from the alignment markers 62 based on the established scale, the known proportions and the resolution of the camera system 14 . The barcode 64 and the numerical code 66 contains identification information pertaining to the coil 22 to which the tag 60 is affixed.
The communication connections are schematically shown in FIG. 6 . The electronic controller 33 includes a zoom controller 82 operating the zoom lens 32 and a pan/tilt controller 84 operating the pan/tilt mechanism 40 . The controller 82 commands the motors 38 (not shown) facilitating the movement of the zoom lens 32 (or 32 b in a two camera system—explained later). The controller 84 commands the motors 38 facilitating the movement of the pan/tilt mechanism 40 . In this particular embodiment, the inventory control system 24 is connected to the operator interface 50 via a wireless Ethernet link 80 . It will be appreciated that any of the communication connections described herein may be hard wired or wireless. It will also be appreciated that the touchscreen 50 and operator interface may alternatively be located away from the crane at a remote location, and operated via the communication link 80 . In such an arrangement, control of the crane and the picker 16 can be performed from any location.
Referring to FIG. 7 , an automatic scanning process 100 involves a continuous scan of the coil field 102 . Referring also to FIG. 1 , the camera system 14 is mounted on the underside of the trolley 12 and therefore scans the field 20 below as the operator navigates the trolley 12 . Images captured are displayed to the operator 104 as shown in FIG. 4 . Coils 22 are observed during this scanning process 100 and the operator must decide whether the coil 22 shown is of interest for reading 106 . If the coil 22 is not of interest to the operator, the operator will continue to monitor the image 104 until a coil 22 does appear that is of interest for reading. When a coil 22 appears that is of interest, the operator first indicates whether the coil 22 is situated at a relative far position such as on the floor or at a relative near position such as being mounted in a secured and elevated position on a truck bed. This is done by selecting a “Near” setting or “Far” setting on the touchscreen 54 . The settings represent the nominal magnifications required by the camera system 14 to be able to read a tag 60 at the corresponding distance. It will be appreciated that there may be any number of magnification levels that can be chosen and should not be limited to only “Near” and “Far” settings. The operator then selects the coil 108 by touching the image of the particular coil 22 at the position which its tag 60 appears on the touchscreen 54 .
It will be appreciated that the camera system 14 may also use the range finder system 13 to determine where the trolley 12 is in the building and whether it is over a floor area or a loading bay (truck mounted coils) to automatically adjust the magnification and focus to appropriate settings without operator input.
In such an embodiment, the arrangement shown in FIG. 19 is preferably used along with a pre-stored lookup table that includes information pertaining to the floor layout of the field 20 . The two range finders 13 a , 13 b obtain the x and y coordinates of the shipping facility in real-time. The lookup table is used to determine if the (x, y) position is over the floor or a truck bed (as one example) and using this information, the system determines the appropriate zoom and focus for the particular coil 22 and instructs the motorized lens 32 accordingly. Similarly, when a coil 22 is first placed in the field 20 , its information can be correlated to the real time position to assign a floor grid location to that coil. Later, when the coil 22 is to be retrieved, an identifier for the coil 22 (e.g. on lift ticket) can be used to determine the location for the coil 22 and the system 10 can automatically position the camera in the vicinity of the coil of interest by tracking the real time coordinates.
At this point, the camera system 14 begins an identification process 109 . To begin, the camera system 14 is given a set of co-ordinates from the touchscreen 54 (or rangefinder system 13 ) representing the position selected by the operator (or automatically detected). These co-ordinates are measured relative to a datum wherein the scale of the image is known based on the wide view magnification used by the camera system 14 and the data provided by the range finder system 13 . The datum represents the centre of the field-of-view of the camera system 14 . The pan/tilt controller 84 then moves the camera system 14 aligning the datum with the given co-ordinates 110 which places the tag 60 substantially within the centre of the field-of-view of the camera system 14 . The camera system 14 also uses the data from the range finder system 13 to map the trolley's position within the field 20 to the given co-ordinates. This provides the inventory control system 24 with a floor grid location to be associated with the tag's information.
This first movement 110 by the pan/tilt mechanism 40 provides a coarse adjustment for centering the tag 60 . Following this pan/tilt operation 110 , the camera system 14 commands the zoom controller 82 to perform a zoom operation 112 , providing an enlarged image of the tag 60 . The zoom controller 82 has two predetermined magnifications, one for the “Near” option and one for the “Far” option. Since the tags 60 are presumably affixed to the coils 22 on the upward facing surface, tags 60 with similar designation (specifically “Near” or “Far”) will be at a substantially similar distance from the camera system 14 . If the operator had selected “Far”, the zoom controller 82 magnifies the image to its “Far” setting. If the operator had selected “Near”, the zoom controller 82 magnifies the image to its “Near” setting which requires less magnification than the “Far” setting since the coils 22 are positioned closer to the camera system 14 . Due to curvature of the upward facing surface of the coils 22 , tags 60 of similar designation may be affixed at slightly varying distances. The zoom controller 82 performs minor focusing at this point if necessary to provide adequate sharpness of the image.
It will be appreciated that the camera system 14 may also use a depth measurement device such as an ultrasonic range finder to determine the distance between the tag 60 and the camera system 14 . This would allow the zoom controller 82 to choose specific magnifications for each tag 60 . This may be necessary in situations where the dimensions of the objects being selected vary substantially.
Following the zoom operation 112 , the camera system 14 performs an alignment adjustment operation 114 . Referring now to FIG. 5 b , the camera system 14 analyses the image and identifies the location and orientation of each of the alignment markers 62 on the tag 60 using an object-finding routine built into the software used by the imaging system, e.g. smart camera software, and previously programmed to identify markers 62 having a particular size and shape.
The camera system 14 determines the position of the dissimilar marker 62 a relative to the other markers and this position dictates the relative orientation of the tag 60 and subsequently the barcode scan direction. If the dissimilar marker 62 a is the upper-leftmost of the markers 62 (as shown in FIGS. 5 a and 5 b ) the camera system 14 determines that a left-right horizontal scan is required. If the dissimilar marker 62 a is the upper-rightmost of the markers 62 the camera system 14 determines that a top-bottom vertical scan is required. If the dissimilar marker 62 a is the lower-leftmost of the markers 62 the camera system 14 determines that a bottom-top vertical scan is required. If the dissimilar marker 62 a is the lower-rightmost of the markers 62 the camera system 14 determines that a right-left horizontal scan is required.
Using the locations of the markers 62 , the camera system 14 then approximates the centre of the barcode 64 . Firstly, since the relative orientation of the tag 60 has been determined, the camera system can measure the width of the tag 60 along the appropriate direction in the image 70 . Furthermore, since the actual width of the tag 60 and the camera system's resolution is known, the camera system 14 can correlate pixel width in the image to the actual width on the tag 60 . Each marker is a particular distance from the centre of the barcode 64 and is a proportion of the tag's width. The distance is measured along a line in the direction that the marker 62 b is pointing and is typically perpendicular to the outermost edge of the marker 62 b relative to the barcode 64 . Based on the proportion of the tag's width, the actual distance on the tag 60 is converted to a number of pixels in the image. This pixel length is then converted to a set of pixel co-ordinates relative to the marker 62 b . Using these relative pixel co-ordinates, the centre of the barcode 64 is approximated and a mark 74 is recorded by the camera system 14 . This process is repeated for the other three alignment marks 62 a,c,d and the average position 72 of the four marks 74 is calculated and its position is recorded by the camera system 14 . These markings are shown in FIG. 5 b.
The camera system 14 uses the position of the average centre mark 72 to determine whether the centre mark 72 lies within a window 76 of acceptable positions surrounding the centre of the image 70 . If the average centre mark 72 is within the acceptable window 76 , the barcode 64 can be read. If the average centre mark 72 is not within this window 76 , the pan/tilt controller 84 commands the pan/tilt mechanism 40 to adjust the camera system 14 thereby placing the average centre mark 72 within the acceptable window 76 of the analysed image 70 . This alignment of the average centre mark 72 ensures the entire barcode 64 is visible in the image 70 and therefore can be properly scanned.
With the tag 60 magnified 112 , properly aligned (per step 114 ), and its orientation known, a barcode string is generated by the camera system 14 by scanning the bar code 116 . The direction of the scan is based on the determined orientation of the tag 60 . This barcode string is sent to the operator interface 50 for comparison with the lift ticket 118 . If the information acquired does not match an item on the lift ticket, the coil 22 is rejected and the system 100 returns to the field level image for the operator to make another selection. If the barcode 64 does match an item on the lift ticket, the camera system 14 returns to a wider view to allow the coil 22 to be grabbed and lifted by the operator 119 using the crane's picker 16 . The automatic scanning process 100 is reinitialised 120 once a coil has been lifted 119 and resumes scanning the coil field 102 until the next operator selection. The system 10 may then interface with the inventory control system 24 to update the stock of coils 22 and process a shipping ticket for delivery of an order of coils 22 .
Therefore, the system 10 enables the identification, scanning and retrieval of objects in a field of inventory from a remote location requiring only a single input from an operator. The operator may remotely scan a collection of the objects and select an object of interest based on a predetermined location for that object. This can be done through an input such as touching the image on a touchscreen to indicate the location of an identifier on the object. The imaging system 14 may then automatically magnify the identifier based on the input, and automatically perform an alignment procedure to orient the identifier according to a desired orientation. The system 14 then automatically reads the identifier, e.g. by scanning a barcode 64 , and uses information provided by the identifier to confirm the location of the object for processing shipping orders, and update an inventory system 24 accordingly. Only a single operator input using a touch or point of a mouse is needed to execute the above procedure. This effectively replaces a manual pan/tilt/focus/zoom operation with a single initial input.
In a further embodiment of the present invention, the camera system 14 utilises two smart cameras 32 a , 32 b as shown in FIG. 8 . The pair of cameras 32 a , 32 b are mounted together on the pan/tilt mechanism 40 similar to the apparatus shown in FIG. 2 . The first camera 32 a is at a fixed magnification and provides a constant overall image of the coils 22 as they are being scanned. The second camera 32 b is equipped with a motorised zoom lens similar to the camera lens 32 in the previous embodiment. In this configuration, the second camera 32 b maintains a magnification close to the level at which a tag 60 can be read and requires only minor magnification adjustments once the pan/tilt mechanism 40 aligns the second camera 32 b with the selected tag 60 .
The use of two smart cameras 32 a , 32 b eliminates the delay time caused by the long zoom stroke being required to increase the magnification from a wide view of the field 20 to a zoomed view of a barcode 64 . While the camera system 14 scans the field 20 , the touchscreen 54 displays an image of the field from the fixed camera 32 a . When the operator selects a tag 60 on the touchscreen 54 , the touchscreen 54 then displays an image from the second camera 32 b while it centres the tag 60 . Since the tags 60 may be affixed at varying distances, the second camera 32 b will make necessary minor adjustments to achieve the desired magnification while centering takes place. Both cameras 32 a , 32 b are mounted on the pan/tilt mechanism 40 , and thus move together to maintain a constant relationship of the location of the tag view within the field of view of the fixed camera 32 b.
During operation, one camera (e.g. 32 a ) is designated as a field camera, and the other camera (i.e. 32 b ) is used at the tag camera for reading barcodes. The field camera 32 a has a fixed focal length, aperture and focus settings. The image size, and depth of field are set so that all coils 22 , no matter what height, are in focus. The overview image is provided to the operator, so that they can select the location (i.e. barcode tag) to enable the tag camera 32 b to locate the tag 60 for reading the barcode 64 . The field camera 32 a monitors the output of the user interface touchscreen 50 , looking for tag identification “touches” or other suitable commands to indicate such identification.
Once the barcode 64 has been identified by the operator, the camera 32 a attempts to identify the barcode 64 and locate its center, to thereby increase the accuracy of the pointing instruction to the pan/tilt mechanism 40 . If the attempt fails, the pan/tilt command defaults to the exact position that the operator touched. Once the pointing operation is complete, the field camera 32 a flags the tag camera 32 b to begin the tag reading process.
The tag camera 32 b has a motorized zoom lens, which is capable of adjusting image size, aperture (brightness and depth of field), and focus (object height). Image size is set by the operator, who may specify whether the coil is on the floor or on a truck bed as explained above. The aperture is held constant, and focus may be scanned to optimize image sharpness for the barcode read.
The tag image may be provided to the operator for manual centering using the touchscreen 50 , or to be able to read the tag number in case the barcode is unreadable. The tag camera 32 b operates to execute the identification process 109 described above. It will be appreciated that the camera 32 b may process the image with an internal processor or may send images to an off-camera processor for processing.
It will be appreciated that the second embodiment described herein includes all of the features of the previous embodiment with an increased zoom speed imparted by use of a pair of smart cameras 32 a , 32 b shown in FIG. 8 , and described above.
The identification process 109 , particularly the alignment step 114 described above is most accurate when reading tags 60 that are affixed to objects have a substantially planar upwardly facing surface, or when the tags 60 are more or less ensured to be affixed such that their alignment is substantially parallel to the floor 20 . When tags 60 are affixed to rolls of steel 22 , the inherent curvature of the upward facing surface of the roll often places the tag 60 at a difficult angle for viewing the alignment markers 62 described above, e.g. when the tags are positioned on a sloping surface of the roll 22 .
An alternative procedure for aligning a tag 160 is shown in FIGS. 9 a - 9 d and 10 - 11 , which is most suitable for centering tags 160 that are likely to be affixed to an object having a sloping surface. In this embodiment, like elements are given like numerals with the prefix “1”.
An image 154 may be obtained according to steps 102 - 112 shown in FIG. 7 , using either the one-camera or two-camera system. The following description is directed towards a two-camera system, but should hold true for a single camera system with different zoom levels, since different zoom levels are inherently at different resolutions. In a two-camera system, when the field camera 32 a sends instructions to the pan/tilt mechanism 40 to center the tag camera 32 b on a barcode, it is common for the tag 160 to be off-center in the tag camera's field of view. This occurs because the resolution of the tag camera 32 b is typically much greater than that of the field camera 32 a , and thus, a single pixel shift (horizontal or vertical) command to the pan/tilt mechanism 40 from the field camera 32 a , translates to a several pixel shift in the field of view of the tag camera 32 b.
As shown in FIGS. 9 a - 9 c , a portion of the barcode 64 may be cut-off in the image 154 , as well as some of the alignment markers 62 . The alternative procedure shown in FIGS. 9 a - 9 d enable the tag camera 32 b to be repositioned in order to orient the barcode 64 such that it is visible for subsequent scanning (i.e. in a desired orientation). Preferably, the centering operation is executed for each scan, regardless of the accuracy of the coarse adjustment caused by the “touch” of the operator. When a tag 160 is accurately centered after the coarse adjustment, only a minor additional time overhead is required, however, when the tag 160 is substantially off-center, the procedure can save several seconds from the read operation when compared to having the operator initiate a manual re-centering.
The alternative procedure for aligning tags 160 uses a series of virtual sensors implemented in a software routine to conduct scans along defined paths in the image 154 to identify or “sense” segments. Segments are regions of similar intensity, differentiated from other regions by an intensity gradient, which is preferably user selectable. Each scan effectively causes a “soft” sensor to interrogate the image and mark or identify segments that it intersects. Preferably, three concentric sensors are used. In the embodiment shown in FIG. 9 a , three sensors each scan an oval path (inner 202 , mid 204 , outer 206 ) to define concentric zones arranged from the center of the image 200 out to the edges of the image field. A marker 208 is placed on the image within each segment identified by a sensor. The number of these points in the image is indicative of distribution of segments in the image.
A well centered tag 160 should produce an equal distribution of segments, and thus markers 208 , about the center of the image 154 , such as that shown in FIG. 9 d . In such a case, the segment positions would then cancel each other out, to produce an average position of the segments, near center 200 . A tag 160 that is towards one side of the image field, e.g. FIGS. 9 a - 9 c , will cause an imbalance in the number of segments on that side, resulting in the average segment position being shifted towards that half of the image 154 . In FIGS. 9 a - 9 c , the barcode 164 is located towards the bottom right portion of the image 154 , and reports a large number of small segments in that area. Small segments are segments that are of a particular size, measured in pixels, e.g. <10 pixels, and are likely to indicate the presence of a barcode bar (white or black). An average 215 of the position of these small segments, measured from the center 200 computes a vector 214 (see FIG. 9 b ).
Referring to FIG. 9 c , a horizontal sensor 210 and vertical sensor 212 can also be used to provide greater accuracy. These sensors scan along the image at the average position 215 as shown in FIG. 9 c , and are used to adjust the average position 215 , to determine a second average position 217 , that better represents the centre of the barcode 164 . A second vector 216 is then produced that more accurately reflects the offset of the barcode 164 . For a horizontal barcode, e.g. FIGS. 9 a - 9 c , the oval segmentation sensors 202 - 206 would provide the vertical offset, and the horizontal sensor 210 , the horizontal offset. Similarly, for a vertical barcode (not shown), the oval sensors would provide the horizontal offset, and the vertical sensor 212 , the vertical offset.
The following describes the alternative procedure for aligning the tag 160 , in greater detail, making reference to FIGS. 9 a - 9 c , 10 and 11 . In the image 154 shown in FIG. 9 a , the three oval sensors 202 - 206 are configured to mark segments that are at least 5 pixels in size, which is the typical width of the smallest barcode bar. It will be appreciated that this procedure may be used for aligning other indicia such as an alpha-numeric string, wherein the threshold of 5 pixels may be adjusted to recognize, e.g., the smallest possible character width.
An edge contrast may be used to identify barcode segments, and is determined through experimentation during an initial calibration. A suitable range is 7-15%, which is high enough to ignore minor noisy segments, but low enough to pick as many valid barcode segments at a relatively poor focus as possible.
As shown in FIG. 10 , when the alignment procedure is executed, a script examines each segmentation sensor 202 - 206 in turn, and determines the number of segments identified by each sensor. First, the sensor of interest is chosen, e.g. starting with sensor 202 , and the number of segments is then determined and compared to a threshold, e.g. 10. If the number of segments is less than 10, chances are that there is no barcode intersecting the sensor 202 , just background noise. In FIG. 9 a , it can be seen that sensor 202 has only 1 segment, and would therefore be ignored in calculating the offset of the tag 160 . However, the next sensor, e.g. 204 , clearly has more than 10 segments, and would therefore be used to calculate the average segment position 215 (shown in FIG. 9 b ).
Since segments on a barcode 164 should not, ideally, be larger than a certain threshold, e.g. approximately 10 pixels, those that are larger than the threshold are ignored, eliminating stray segments, background segments etc. This ignores the curvature of the path in which the sensors may perform their scan. An oval path may report a larger segment width since the path in which it travels may not traverse the segment along the shortest path. This would result in a measured segment width that is larger than that of the segment's true size. Segments can also be identified as larger than they truly are, if adjacent barcode bars are missed due to poor focus etc. The threshold is chosen to accommodate operational variations.
Turning to FIGS. 9 a and 10 specifically, since sensor 202 has been ignored, sensor 204 is next analysed. There are greater than 10 segments according to the image 154 in FIG. 9 a , therefore, the first segment is selected, and its size determined. If the segment selected is smaller than the threshold, i.e., 10 pixels or less, its coordinates are saved to include in the average position. This is repeated until each segment has been analysed. As long as at least one of the segments has not been determined as “bad”, i.e., above threshold, an average horizontal and vertical position are determined based on all coordinates saved during the analysis.
The above process is repeated for each sensor, which in the example shown in FIG. 9 a would involve one more iteration to evaluate sensor 206 . If it was determined that all sensors were ignored, the aggregate average position is set to the center 200 . If at least one of the segments has not been ignored, an aggregate average position 215 using all included sensors (these are shown in isolation in FIG. 9 b ), and all included segment positions is found. This calculation produces vector 214 shown in FIG. 9 b.
Once all sensors have been analysed, the horizontal and vertical segmentation sensors may be used, as shown in isolation in FIG. 9 c . It will be appreciated that using the horizontal 210 and vertical 212 sensors may be an optional procedure, however, the use thereof does provide a more accurate determination of the center of the barcode 164 .
The steps in using the horizontal 210 and vertical sensors 212 is shown in FIG. 11 , making reference to FIG. 9 c . The horizontal sensor 210 is placed along the image 154 at the average vertical position (i.e. Y coordinate of 215 ) determined according to FIG. 10 . Similarly, the vertical sensor 212 is placed along the image 154 at the average horizontal position (i.e. X coordinate of 215 ). A script will determine which line sensor ( 210 or 212 ) has a greater number of segments, to decide whether the barcode 164 is oriented vertically or horizontally. It is clear from FIG. 9 c that the horizontal sensor 210 has a greater number of segments, and the barcode 164 is clearly oriented in a horizontal fashion.
In this example, since the horizontal sensor 210 has a greater number of segments, the process continues on the right hand path shown in FIG. 11 . Once the proper sensor has been chosen, the number of segments identified by that sensor is determined, and if there are fewer segments than a particular threshold, the process is bypassed. In FIG. 11 , that threshold is three (3) segments. If the horizontal sensor 210 has identified three or more segments, which in FIG. 9 c is true, a loop commences that measures the size of each segment, and if the segment is smaller than a threshold, e.g., 15 pixels, then the coordinates of that segment are to be included in the second average position 217 . Similar to the oval sensors, this process is repeated for each segment until all have been analysed.
If all segments were bad, the average X position is set to the X coordinate of center 200 , and if not, an average X position is computed for all included segments. Differential X and Y measurements are then calculated by subtracting the X coordinate of center 200 from the average X position and the Y coordinate of the center 200 from the average Y position. In this example, the average Y value remains the one calculated by the oval sensors. The differential measurements are then compared to respective thresholds, and if the differential measurements are not above those thresholds then the barcode 164 is within the suitable limits and a move is not required. If however at least one of the X or Y differential measurements are greater than its respective threshold, a second vector 216 extending from center 200 to the position dictated by the X differential and Y differential measurements, i.e. 217 , is computed. This vector 216 provides a better estimate of the center of the barcode in the horizontal direction, as shown in FIG. 9 c.
It will be appreciated that the steps taken for measuring a vertical barcode are similar to those that have been described above, and therefore, need not be reiterated.
As long as at least one of the differential measurements is greater than its respective threshold, a pan/tilt operation will be performed by the pan/tilt mechanism 40 , which aligns the tag 160 within the image as shown in FIG. 9 d . At this point, the imaging system 14 will analyse the image and determine if further adjustment is needed, or if a particular scan direction is needed. For example, the tag 160 is oriented “up-side-down”, and thus the barcode scan operation would need to take this into account. The imaging system 14 may then determine the up-down/left-right orientation and scan accordingly.
To achieve the most accurate results: a reasonable focus should be used so that the maximum number of barcode segments may be encountered; a reasonably consistent background is preferred, which is difficult to control, however should be considered; and if possible, having no other tags within the field of view of the cameras 32 a , 32 b is also preferred, to minimize confusion with the background.
It will be appreciated that the above alternative alignment procedure can be used in place of the procedure shown in FIGS. 5 a and 5 b , and the choice of which procedure to use, is dependent on the application. For instance, in an application where the objects being scanned are rectangular, e.g., shipping containers, either alignment procedure is suitable. On the other hand, in applications where the objects are curved, e.g., rolls of steel, the alternative alignment procedure is more appropriate.
The tag alignment procedure shown in FIG. 9 can be prone to mis-alignment in less than ideal conditions, e.g. where the tag 60 is out of focus. In many practical applications, the system performs a tag centering operation prior to focussing the tag, in order to reduce inspection time. If the system first performs the focus operation, it is likely in many instances that there is not a great deal of the barcode 60 in the image and thus will have to perform a tag centering procedure and then re-focus the tag. Ideally, the tag centering procedure should only be performed once since, every time the procedure executes, the inspection time increases and the inherent time delays due to mechanical movements are also increased.
In cases such as that shown in FIG. 12 , poor focus and/or poor initial alignment can result in too few segments being detected. The resultant segmentation shown in FIG. 12 would determine that the tag 260 is almost perfectly centred and no movements are necessary when in fact a correction is needed to align the tag 260 . Such a false positive can be attributed to the sensitivity of the line sensors and the poor image focus (poor focus not shown in FIG. 12 in the interest of clarity). In order to overcome the potential shortcomings of the use of the procedure shown in FIG. 9 , another embodiment, shown in FIG. 13 can alternatively be used.
Referring now to FIG. 13 , an array of square area segments 262 are evenly arranged throughout the image. Area sensors 262 are typically more robust than line sensors since, by definition, the sensors 262 detect within an area (i.e. 2-D) as opposed to only the pixels that are included in a 1-D line. Line sensors, as discussed above, detect single white-to-black-to-white transitions and thus depend a single 1-D transition. The area sensors 262 are capable of correlating 2-D boundaries in its respective area.
Each sensor 262 looks for 2-D segments of the same geometric property as a typical barcode strip having the same magnification (based on data that can be pre-stored). Each of the sensors 262 is associate with a respective offset value measured with respect to the origin (0, 0) of the image (e.g. centre). For example, the sensor 262 in row 1, column 1 (i.e. upper left corner) has an x-offset of −240 and a y-offset of −160, while the sensor 262 in row 2, column 3 has an x-offset of +80 and a y-offset of zero (0). If the number of 2-D segments detected in a particular area exceeds a predetermined threshold (e.g. 5), then its predetermined offsets are added to a total offset, which includes an average of all applicable offsets. The threshold is used to exclude sensors 262 such as row 2, column 2 whose segments do not contribute to identifying the location of the barcode 64 but may have detected other features of the tag 60 .
The predetermined offsets for all applicable sensors 262 are added together and averaged to determine an approximate total (x, y) offset. In the example shown in FIG. 13 , sensors (1, 3), (1, 4), (2, 3) and (2, 4) contribute to the offset calculation and the approximate offset is found to be (160, −80), i.e. move the tag left by 160 pixels and down by 80 pixels.
Preferably, in order to fine tune the offset calculation, a horizontal line sensor 266 and a vertical line sensor 264 are placed at the approximate offset (e.g. 160, −80) and the segments detected along them are incorporated into the offset calculation. The line sensors 264 , 266 are used to accommodate horizontally and vertically placed barcode tags 60 . The one that finds the most segments along its length (preferably subject to a predetermined threshold), determines the orientation of the tag (e.g. horizontal in FIG. 13 ) and contributes to the final offset calculation. The average of all the segments found by the line sensors 264 , 266 adds a fine adjustment to the approximate offset resulting in the final offset. In the example shown in FIG. 13 , the final offset is (122, −106).
To create a true one-touch centering operation, and to reduce misreads, the cameras 34 a,b can be instructed to return to their home position (aimed at the normal barcode position on a coil directly under the picker 16 ) and initial state (zoom, iris level, starting focus) when a preset idle time is exceeded after each read operation. While the operator moves to the next coil, the cameras can reset themselves for the next one-touch operation whereby the two cameras move together to a preset orientation under the control of the pan/tilt unit 34 and the adjustable lens returns to its “home” zoom position etc.
A screen shot of an application program interface (API) 400 provided on the touchscreen 54 is shown in FIGS. 14-18 for the two-camera arrangement shown in FIG. 8 . The API 400 provides a field view 401 from one lens 34 a and tag view 403 from the other lens 34 b . The views 401 , 403 preferably use a tab organization such that an operator can easily switch to an enlarged tag view 403 by simply touching the tag view tab. The API 400 also comprises a status bar 402 for indicating the current operation being performed by the system 10 . In FIG. 14 , the status bar 402 instructs the user to press on a tag in the field view (see FIG. 4 ) to begin the barcode read. Once the user presses the tag 60 , the centering and zoom operations are performed and an image of the tag 60 is provided in the tag view 403 where a centering operation takes place and the barcode is then read. Once the barcode 64 has been read, it will be displayed on a barcode display 404 . The laser rangefinders 13 a , 13 b continuously determine the (x, y) coordinates and correlate these to a floor location, which is shown in a location display 405 .
The API 400 also comprises a reset option 406 that is used to reload the software, a floor layout indicator 407 (showing “floor level” in FIG. 14 ), an advanced option 408 for adjusting configuration settings, and a help option 409 that loads a graphical help manual (see FIG. 18 ).
The API 400 checks its communication ports to see whether a continuous stream of data is being received from the laser range finders 13 a , 13 b . A stop watch algorithm is used whereby each time a new set of data is received, the starting time is reset and the time elapsed returns to zero and starts over. If the ports remain inactive for a period of time (e.g. 10 seconds), the API 400 will display a troubleshooting window 410 giving an overview of the problem and possible causes and remedies as seen in FIG. 15 . To attract the user's attention, the location display may change colour and the reset option 406 is highlighted to reflect a new set of commands when selected.
The troubleshooting window 410 first states the date, time and the problem encountered. This information is appended to an external log file for archiving. A sequential trouble shooting guide is then listed. Under normal operations ( FIG. 14 ), the reset button instructs the cameras 34 a,b to resume their initial states and recalibrates the mechanical movements of the pan/tilt mechanism 40 . During an operational error such as that described above, the reset button 406 changes colour and pressing it reloads the API 400 instead of sending a command to the cameras 34 a,b and pan/tilt mechanism 40 . The reload operation is to eliminate the possibility of a software glitch from the diagnostic tests. For example, the reload may indicate that a software glitch interrupted communications with the laser range finders 13 a , 13 b rather than a physical connection being lost which can save unnecessary troubleshooting.
The above-described polling progress is preferably continuous and thus once the problem has been fixed, the troubleshooting window 410 automatically disappears and the icons return to their original colours and functions.
Similarly, if a touch command sent to the cameras 34 a,b via the camera display 401 is broken, the field view icon turns red and the troubleshooting window reappears (see FIG. 16 ) with relevant troubleshooting tips. Preferably, the API 400 is capable of reflecting more than one problem simultaneously. Active monitoring is preferably done at the level closest to the control console 18 . Since the pan/tilt unit 40 and motorized lenses 32 are directly connected to the tag view camera, it periodically polls for a response. The system will try to re-establish a connection once a response is not received, after a particular threshold. The camera 34 passes a parameter to the API 400 indicating the problem as noted above.
When the operator presses the help option 409 a help menu 412 as shown in FIG. 17 is displayed. The operator has the option of exiting the API 400 by pressing option 413 to access the native PC desktop (preferably password protected). The API 400 can be reloaded by selecting the reload option 414 , the help option can be exited by selecting option 416 , and a help manual can be loaded by selecting the help option 415 .
An example help manual 420 is shown in FIG. 18 . Various tabs 421 are provided for providing troubleshooting tips for particular operations. A graphical display 422 and a textual display 423 are provided for each tab to assist the operator in diagnosing the problem. An exit button 424 is provided and contact information 425 for further support. Preferably, advance options are provide to enable an operator to configure the system 10 settings, such as the shutter speed, light intensity and zoom levels for calibration purposes.
An example advanced help manual 320 is shown in FIG. 21 . This menu 320 allows the operator to perform manual zoom in 322 and zoom out 324 operations as well as adjust the iris 328 or adjust the focus 330 manually. The operator is also given the option to read the tag again 326 and exit the manual 332 when finished with the advanced options. It will be appreciated that any number of advanced options can be provided and may be guarded by a password protection mechanism to prevent unauthorized tampering.
Often, a shipping or storage facility includes more than one crane and thus includes more than one identical system 10 running the same software in the same building. In order to differentiate between two or more systems, an identifier for each system can be used, e.g. using a hardwired parallel port dongle. A different wiring combination can give each dongle a hard coded identifier. The dongles are physically attached to the system's parallel port and its identifier is automatically retrieved during system login, which accurately recognizes each system without human error. A lookup table can then be used to match the system identifier with the rest of the crane information such as weight, model and make. The system identifier allows the equipment to be completely portable so that it can be swapped between cranes during maintenance periods or if a machine is decommissioned. When the system initiates it can automatically determine the crane in which is has been installed and avoids the operator having to remember to update settings or enter such settings. It will be appreciated that the system identifier can also be set in software and, where only one crane exists in the same building, this option can be disabled.
As shown in FIG. 1 , the system 10 interfaces with an inventory control 24 . The inventory control 24 and the camera system may be fully integrated into a single system or may operate independent of one another while interfacing with each other as shown. In one embodiment (not shown) the API 400 includes a window for the camera system and a window for the inventory system but may also utilize a tabbed window to enable the operator to switch between the two interfaces. For a more ergonomic arrangement, a separate display (not shown) can be used to display an inventory interface on a separate display from the one shown in FIG. 3 .
Separate interfaces may be considered if the camera control system and inventory control system require different levels of authority for access. If access to the inventory system is limited to an operator, a read-only display could be provided without write capabilities. Also, security issues may dictate whether or not the inventory system and camera system can be integrated. In an integrated system, the camera sub-system sends location and barcode information that is already obtained to the inventory sub-system for updating or cross-referencing.
In a fully integrated system, an incoming coil 22 enters the facility on a truck bed, and the driver submits a billing sheet with an ID for the coil to an inventory control person or scans it into the system. The ID is loaded into the database and the inventory control 24 determines historical data and physical data to determine the best spot for the coil 22 . For example, the inventory control would have access to the floor layout and the look-up table showing available locations. The location and coil information may then be sent to the crane cab 18 whereby the coil tag 60 is first scanned to confirm that the coil matches the billing sheet and the coil 22 is lifted and placed at the appropriate location. With a sophisticated crane, a fully automated placement can be performed since the system 10 can find a location using the range finders 13 a , 13 b and can interface with the inventory control 24 to match a vacant spot with a location. Ideally a proximity sensor or the camera 14 system can be used to confirm that a spot is vacant before the coil 22 is lowered.
Once the coil 22 is placed, API 400 notifies the inventory control 24 which in turn updates its database to “fill” the vacant spot. For an outgoing item, a lift ID can be entered into the system either in the crane or from a remotely operated console (not shown). The lift ID is used to find the location for the coil 22 which in turn commands the crane or notifies the operator in the cab of the location. The location can be used automatically or manually to locate the coil 22 . The tag is then read to confirm the inventory and the coil 22 is hoisted and placed on an outgoing truck.
The above example can be fully automated or partially automated depending on the capabilities of the system and the safety requirements. An operator may be used but placed outside of the crane in an office. By using the illumination system 308 , the facility would not require lighting in a fully automate embodiment but only require the localized light that is only provided when a coil is being placed or retrieved.
Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. The entire disclosures of all references recited above are incorporated herein by reference.
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In general terms, the present invention provides a method of automatically scanning an inventory field to allow the selection of a desired item for retrieval. A camera is positioned in the crane trolley located above the field. The camera continuously performs a scan of the field displaying an image to the operator of the items being scanned. This real-time image allows the operator to distinguish between items scanned in the field. The operator can subsequently choose the desired item triggering the camera system to automatically capture desired information from the item which is in turn communicated to an inventory control system. The camera system mitigates the requirement of a second individual to communicate information between the field and the operator.
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BACKGROUND OF THE INVENTION
This invention relates generally to a conveyor belt scraper.
It is known to make use of a conveyor scraper wherein the scraping element, or each scraping element when there are a plurality of such elements, is flexible or is mounted to a spring of suitable form which allows to-and-fro movement of the scraping element, during use.
With the aforementioned type of scraper cleaning of a conveyor belt is achieved by adjusting each scraping element towards the belt surface and applying pressure so that the flexible scraping element, or the spring, as the case may be, is tensioned to remove slack and creep and to provide the necessary resistance to the moving belt so that material adhering to the belt is removed.
The pressure which is applied to flex the scraping element or tension the spring is obtained by forcing an edge of the scraping element into contact with the belt surface, with a suitable degree of force. The pressurised contact surface between the belt and the scraping edge accelerates the wear rate of the tip of the scraping edge and can increase wear on the belt surface. It is also known that the pressure exerted by the scraping element on the belt surface must be increased, as belt speed increases, in order to provide the necessary cleaning resistance.
Protrusions on the belt surface cause the scraping element to deflect away from the belt whereafter the element rebounds naturally to its original position. This action can cause additional damage to the belt surface. In certain instances the rebound results in ongoing oscillations and vibrations of the scraping element and if this movement occurs in harmony with the natural vibration frequency of the conveyor belt severe belt damage can result, an effect which is compounded as the conveyor speed increases.
Also, unrestricted movement of the scraping element can cause additional damage when the belt reverses, and when used in the primary cleaning position if a belt joint/splice opens up, or other protrusions impact on the scraper.
SUMMARY OF INVENTION
The invention provides a method of assembling a conveyor belt scraper which includes at least one scraping edge fixed to a support at least by means of a biasing member which includes the steps of:
(a) prestressing the biasing member in a first sense, (b) maintaining the biasing member prestressed, and (c) mounting the conveyor belt scraper adjacent a surface of the belt whereby, in use, when the scraping edge exerts a scraping action on the belt and is deflected away from the belt, the biasing member is further stressed in the first sense.
“Stress” as used herein denotes a state which is brought about by tensile, compressive or torsional force, or a combination of any of these factors, and “pre-stress” means a state of the aforementioned kind which is brought about beforehand.
The method may include the step of limiting the degree of movement of the scraper towards, and away from, the belt.
The biasing member may be prestressed in a first direction which, once the conveyor belt scraper is installed, is generally in a direction which is away from a belt surface which is to be cleaned. The biasing member is restrained from moving towards the belt surface so that the biasing member is retained in its prestressed state. Movement of the scraping edge away from the belt surface, which occurs during use, leads to the biasing member being further stressed in the first direction.
The invention may include the step of controlling the degree of prestressing in the first sense. Thus the biasing member may be prevented from being stressed beyond a predetermined level. This may be achieved in any appropriate way and for example a mechanical stop may be used which prevents the scraping edge from being moved beyond a predetermined point towards or away from the belt surface.
In step (c) the conveyor belt scraper may be mounted so that the scraping edge is in light contact with, or slightly spaced from, the belt surface which is to be cleaned.
The scraping edge may be provided on a scraper element which is fixed to the biasing member.
The invention also extends to a conveyor scraper element which includes a biasing member and a component with a scraping edge supported by the biasing member and wherein the biasing member is engageable with a support, with the scraping edge not in contact with a belt surface and with the biasing member in a prestressed state.
The biasing member may include any suitable device and may for example be a leaf spring which may be made from metal or a plastics material.
The biasing member may extend from the support and the scraping edge may be positioned remote from the support.
The biasing member may be located between two deflector surfaces. The deflector surfaces may be formed by individual components or by respective surfaces on a composite or integral component.
The biasing member may be secured to the component by means of any suitable fasteners, eg. rivets or bolts, or it may be engaged with the component by means of interengageable complementary formations on the component and the biasing member.
The biasing member may be secured to the support in any appropriate way and use may for example be made of rivets of other fasteners to secure the biasing member to the support. Again it is possible to secure the biasing member to the support by means of interengeable complementary formations on the biasing member and the support.
In one form of the invention the scraper element includes first and second deflector plates and the scraping edge component is secured to respective first ends of the plates. The biasing member is positioned between the plates and preferably is secured to one of the plates. One of the plates may abut the support, or any other structure, thereby to retain the biasing member in a prestressed condition. The extent to which the biasing member may be prestressed may be limited when the other plate is brought into contact with the support or other structure or adjustable stops for, in this way, movement of the biasing member may be controlled.
In a different form of the invention the scraper element includes a body formed from a suitable material, eg. a plastics material using an injection moulding or casting process, and respective surfaces of the body form deflectors or deflector surfaces. The biasing member is engaged with a suitable formation or formations in the body.
An additional formation on the body may be engageable with the support or any other structure to retain the biasing member in a prestressed state. Similarly a formation on the body can be brought into engagement with the support or other structure or an adjustable stop or stops thereby to control the degree of stress, whether in tensile, compressive or torsional form, which is imparted to the biasing member.
A plurality of the scraper elements may be assembled to provide a scraper assembly. This may be done using any appropriate technique and for example the scraper elements may be slidably engaged with an appropriate support structure. The scraper elements may be assembled in any appropriate configuration in an elongate array, eg. in-line, or in a staggered array.
The complete scraper assembly may be supported on adjustable or resilient mountings to accommodate normal scraper wear and to allow the passage of protrusions and joints in the conveyor belt.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by way of examples with reference to the accompanying drawings each of which has two figures respectively illustrating a conveyor scraper element according to the invention from the side and from an end respectively.
In the accompanying drawings:
FIG. 1 illustrates a conveyor scraper element according to a first form of the invention mounted adjacent a belt surface which is to be cleaned and used as a primary scraper,
FIG. 2 shows a conveyor scraper element which is similar to that shown in FIG. 1 but wherein the conveyor scraper element is used as a secondary scraper,
FIG. 3 shows a conveyor scraper element according to a second form of the invention suitable for use as a primary scraper, and
FIG. 4 illustrates a variation of the configuration shown in FIG. 3 suitable for use as a secondary scraper.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 of the accompanying drawings illustrates a conveyor scraper element 10 according to a first form of the invention from a side and from one end respectively. In this example the conveyor scraper element includes a body 12 which is moulded from a suitable plastics material, eg. reinforced nylon, and which has a roughly triangular shape in cross section. An upper end or apex of the body has an elongate groove 14 which is narrower at its mouth than at its base. Sides 16 and 18 of the body taper outwardly and downwardly from the apex and are referred to herein as deflector surfaces.
At its lower end the body has two wings or ribs 20 and 22 respectively projecting downwardly from the deflecting sides 16 and 18 .
A central portion of the body is formed with a fairly substantial slot 24 which has a base 26 which is in the nature of a circular cylinder.
A scraping component 28 is mounted to the slot 14 . The component 28 has a rib 30 which is of complementary shape to, and which is slideably engageable with, the slot 14 . The rib is held firmly in the slot by means of rivets or other fasteners 32 which pass through holes in the upper end of the body 12 and registering holes in the rib.
A scraping edge 34 of any appropriate scraping material known in the art is mounted to a slot 36 in a projecting outer surface of the component 28 .
A leaf spring 40 is engaged with the formation 24 . The spring has a rounded upper end 42 which is complementary in shape to the cylindrical base 26 of the formation. At its lower end the spring has a rounded base 44 which is positioned in a gap formed at a central location in a mounting and supporting track 50 .
The spring is made from a suitable material, eg. spring steel or an appropriate plastics material, with adequate corrosion resistant properties, which has an acceptable cycle life time.
The support and mounting track or rail 50 is generally in the nature of an inverted “U” to fit over square tubing and has an upper elongate slotted formation 52 which is used for mounting the scraping component. The formation 52 corresponds in shape to the lower end of the spring 40 and the base 44 . It is apparent that the spring can be engaged with a sliding action with the support by sliding the base 44 into the formation 52 .
The geometry of the body and the design of the support 50 are such that, in order for the body to be engaged with the support, the spring must be prestressed. In the illustrated example this is achieved by bending the body in the direction of an arrow 56 which is away from the surface 58 of a belt 60 which is to be cleaned. The spring is thereby flexed and the body can be pushed over the support with the ribs 20 and 22 extending downwardly on opposing sides of the support. Once the force which is used to bend the spring in the direction 56 is released, the spring attempts to revert to a neutral position and in so doing moves the body in a direction opposite to that indicated by the arrow 56 , to a limited extent. A lower inner surface of the rib 20 is thereby brought into contact with an upper left hand corner of the support 50 and this limits the degree to which the spring can relax. The spring is thereby held in a tensioned or prestressed state.
FIG. 1 shows the scraper element 10 mounted adjacent the belt surface 58 and acting as a primary scraper. The support 50 is positioned so that the scraping edge 34 is lightly in contact with the belt surface 58 . The spring is, as noted, constantly held in a biased or prestressed condition.
The degree of flexing or pivoting of the body, which is permitted, is restricted and the body can move to a limiting position, away from the belt surface, indicated by means of a dotted line 62 . At this stage the rib 22 abuts an upper right hand corner of the support 50 and this limits the permitted extent of movement of the body and hence of the scraping edge 34 away from the belt surface 58 . The body is allowed sufficient movement to allow the scraper blade or edge 34 to follow variations in the belt thickness or undulations in its outer surface and to deflect sufficiently to allow protrusions, which are generally encountered, to pass the scraper edge. These features have the following benefits:
(1) less applied pressure is required for the scraper element to resist the forces of the carry-back material on the belt, in order to perform its cleaning function. This reduces scraper blade and belt wear; (2) deflection of the scraper element is limited thereby reducing rebound impact; (3) oscillation of the scraper element is restricted thereby interrupting any vibration cycle and preventing sympathetic vibrations and resulting chatter, damage etc.; (4) in situations where the conveyor belt is reversed over the scraper element, forward movement of the scraper element is restricted, preventing it from digging into the belt, an action which could damage the belt or the scraper element; (5) when the scraper element is used as a primary cleaning device the restriction on forward movement reduces the possibility of the scraper element being snagged by a protrusion from the conveyor belt, a factor which could cause damage to the belt or the scraper element.
FIG. 2 illustrates a variation 10 A of the arrangement shown in FIG. 1 wherein the scraper element is used as a secondary scraper. The configuration shown in FIG. 2 is not described in detail and, where applicable, components which are the same as those shown in FIG. 1 are designated with similar reference numerals.
The upper edge of the body 12 has a scraping component 28 A attached to it with the element being oriented so that the scraping edge 34 A extends upwardly and not to the side, as in FIG. 1 . This allows the scraper element to be mounted in a vertical configuration, similar to what is shown in FIG. 1 , but with the scraping edge being available for a secondary scraping action as opposed to the primary scraping action of FIG. 1 .
FIG. 2 also illustrates that the support, designated 50 A, can be engaged with a sliding action with a base support 64 . The base support 64 is attached to fixed structure adjacent a belt 60 A, at an appropriate location, and the support 50 A, which is assembled with the scraping element or elements under factory conditions, is then readily engaged on-site by sliding the support 50 A onto the base support 64 .
FIG. 3 shows a conveyor scraper element 10 B which includes a body of two metal deflector plates 70 and 72 respectively which are joined at an apex formed by upper ends 74 to which a scraping component 76 is attached. The component 76 has a scraping edge 78 of a suitable hard-wearing material fixed to it in a manner which is known in the art. The scraper element 10 B is secured to the deflector plates by means of rivets or bolts 80 .
The deflector plates extend downwardly and away from each other giving a generally triangular or pyramid-type construction. A leaf spring 82 of any suitable material is fixed to an inner surface of the deflector plate 70 . A lower end of the spring is clamped between angle brackets 84 which are fixed to an upper surface of a support 50 . A lower end of the deflector plate 70 abuts an upper left hand corner of the support 50 and retains the spring 82 in a permanently prestressed condition with the spring attempting to move to a neutral position in a direction of an arrow 86 .
A lower end of the deflector plate 72 , designated 88 , is spaced from a right hand upper corner of the support 10 . It is evident that the scraper element 10 B is similar to what is shown in FIG. 1 and that if the scraping edge 78 is moved in a direction opposite to that indicated by the arrow 86 the lower end 88 of the deflector plate 72 limits the extent to which movement of the scraping edge can take place away from a belt surface which is being cleaned.
Apart from limiting the degree of movement of the spring 82 the deflector plates protect the spring and shield it, at least to some extent, from mechanical damage, and from foreign material, water and the like.
FIG. 4 illustrates a scraper element 10 C which is a variation of the configuration shown in FIG. 3 . The scraper element includes deflector plates 70 A and 72 A respectively with the plate 70 A being shaped in a different form to the plate 70 . A scraping component 76 A, with a scraping edge 78 A, is positioned between upper edges of the plate 70 A and 72 A and is riveted in position.
A lower end of a centrally positioned spring 82 A is damped between two brackets 84 A which, in turn, are attached to a base plate 90 . A channel 92 with inwardly sloping side walls is fixed to an upper surface of a support 50 . The base plate and the brackets can be engaged with a sliding fit with the channel 92 .
Although the scraper element 10 C is a variation of the arrangement shown in FIG. 3 it is evident that it is used as a secondary scraper in a manner similar to what has been described in connection with FIG. 2 .
It is also to be noted, in connection with all of the embodiments of the invention, that only one scraper element has been described. It is evident that a plurality of scraper elements may be positioned in line with each other to form a longitudinally extending array of scraper elements with each scraper element being positioned above the support 50 . Clearly it is possible to arrange the scraper elements in other configurations, eg. in a staggered array of two or more rows.
Another factor is that the support 50 , in each embodiment of the invention, may itself be supported on a vertically and horizontally adjustable mounting 66 , see FIG. 2 , or it may be supported on a torsion arm 68 which allows resilient movement, or it may be mounted to shock absorbing structures or self-support mechanisms such as airbags, pneumatic or hydraulic cylinders, counterweights or torsion-type mounting assemblies.
It is also possible to modify the conveyor scraper element to adjust the degree of bias, or prestressing, which is applied to the element. For example FIG. 1 illustrates two grub screws 100 which are mounted in the body 12 , bearing against the support 50 , which can be adjusted to deflect the spring 40 to a greater or lesser extent, but which still act as a stop to prevent the spring from moving to a de-stressed condition.
Similarly, in FIG. 3 , a screw 102 which is fixed to the spring 82 bears against an inner surface of the deflector plate 70 and can be adjusted to increase or reduce the degree to which the spring is prestressed.
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A method of assembling a conveyor belt scraper which includes at least one scraping edge fixed to a support at least by means of a biasing member which includes the steps of prestressing the biasing member in a first sense, maintaining the biasing member prestressed, and mounting the conveyor belt scraper adjacent a surface of the belt whereby, in use, when the scraping edge exerts a scraping action on the belt and is deflected away from the belt, the biasing member is further stressed in the first sense.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application Ser. No. 61/802,137 filed Mar. 15, 2013 entitled Electronic Device Accessory, which is incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electronic device accessories, and more particularly, to a neck strap or harness with a built in electronic device holder that will allow users to have easy, usable, hands free access to and storage of the device and be able to utilize the device more effectively and safely.
2. Description of the Related Art
Electronic devices including but not limited to cellular phones, smart phones, PDA's, tablets, tablet PC's, electronic readers and other such devices have become a widely used means of communication, entertainment, and business in today's society. The physical use of these devices requires the device to be on a stable surface or in the user's hand(s). It is common practice for a person to use the device or check for new/recent activity numerous times within a short period of time. After each short use, the user tends to stow away the electronic device only to get it out again. The frequent and continual pattern of use, storage and retrieval causes individuals to have one or both hands occupied a majority of the time. This disarms the user from full function of their hands. Additionally, this repeated pattern results in the mishandling of the device and subsequent damage due to the mishandling.
Electronic device accessories exist on the market and are used to hold and protect your device in different ways namely to enclose your device within itself so that it will be protected and/or so that it that will clip to your belt or purse. There are also device holders that will hold your phone in your vehicle. There are also device lanyards or holder pockets, namely for smart phones, that go around your neck. There are also device stands. However none of the prior art devices allow for wearable use.
SUMMARY OF THE INVENTION
This disclosure departs from what is available on the market today by providing a wearable base that fills the need for active users of such devices to be able to use their device with reduced reliance on the device being held in their hands and as a result disarming the user from performing other important functions and compromising reaction times when the hands are needed for other actions and reduced risk of mishandling and damage to the device.
This disclosure provides a fast, easily accessible holder for small electronic devices such as a mobile phone, tablet, or music player. The electronic device holder consists of two parts, a stand holder that allows a user to modify the angle, rotation, and vertical position of the electronic device and base that attaches to a person. The stand is detachable from the base and may be used without the base as a general stand. When the stand is attached to the base, the user may enjoy the electronic device without having to use their hands.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a profile view of the disclosed embodiment.
FIG. 2 is a side profile view of the stand portion of the disclosed embodiment without torso connection.
FIG. 3 is a close-up view of the pivot joint.
FIG. 4 is a profile view of the disclosed embodiment on a surface.
FIG. 5 is a top down view of the torso connection.
FIG. 6 is a front view of a person wearing the disclosed embodiment.
FIG. 7 is a back view of a person wearing the disclosed embodiment.
DETAILED DESCRIPTION
Referring to FIG. 1 , the electronic device holder 1 is comprised of a stand portion 2 and a base 30 . The stand portion 2 comprises a device holder 3 , frame 4 , and an attachment member 5 which may be removably inserted into the base 30 . The base 30 is fitted with a torso strap 31 and neck strap 32 to aid in attachment to a person.
Referring to FIGS. 1-4 , the frame 4 is connected on one end to a device holder 3 and on a second end to an attachment member 5 . The frame 4 consists of a top frame member 6 , telescoping element 7 , support member 8 , and pivot joint 9 . The top frame member 6 is located at the top of the frame 4 and is connected to the telescoping element 7 . The telescoping element 7 allows the frame 4 to lengthen or shorten based on the user's needs. The support member 8 is attached to the bottom telescoping receiving member 10 of the telescoping element 7 to provide additional support. The support member 8 and bottom telescoping receiving member 10 are attached to one end of the pivot joint 9 . The pivot joint 9 is manually activated through pressing of the pivot joint release button 11 .
The attachment member 5 is attached to the other end of the pivot joint 9 from the bottom telescoping receiving member 10 and support member 8 . The attachment member 5 is comprised of a suction cup 12 , flange 13 , and screw mount 14 . The screw mount 14 is directly attached to the pivot joint 9 . The pivot joint 9 allows the device holder 3 and telescoping element 7 to rotate 180 degrees in respect to the attachment member 5 .
The device holder 3 is generally rectangular in shape. The device holder 3 is attached on its rear face 15 to the frame 3 through a ball and socket joint 16 that is attached to the top frame member 6 . The ball and socket joint 16 , as seen in FIG. 3 , allows the device, holder 3 to rotate in a complete circle and be adjusted in all 360 degrees. Once a device is attached to the device holder 3 , the device holder 3 may be moved by the user to achieve the desired viewing angle.
Electronic devices 20 , such as tablets, music players, and mobile phones, are attached to the device holder 3 through a variety of attachment mechanisms. The front face 17 of the device holder 3 contains a sticky pad 18 that allows for attachment and removal of an electronic device without leaving any residue. Additionally, clips 19 positioned along the edges of the device holder 3 attach to an electronic device and secure it to the device holder 3 . The specific device holder attachment mechanisms vary depending on the size, weight, and use of the electronic device. Additional attachment mechanisms such as elastic bands or fitted rubber sleeves may be utilized. Attachment mechanisms may be used in unison or in combination to achieve sufficient level of attachment.
As seen in FIG. 4 , the stand portion 2 may be mounted on any relatively flat surface 21 . The suction cup 12 is firmly placed on the flat surface 21 . When the screw mount 14 is screwed down, the flange 13 pushes on the suction cup 12 causing the center of the suction cup 22 to be pushed down to the flat surface 21 . This creates a pressure differential with sufficient force to hold the stand 2 upright and keep it from falling over.
Referring to FIGS. 1 and 5 , the base 30 is generally circular in shape and consists of hard shell having a front wall 33 , back wall 34 and a side wall 35 . The sidewall 35 encompasses approximately two thirds of the circular base creating an opening 36 at the top and shortened front wall 33 as compared to the back wall 34 . A pocket 37 is formed by the front wall 33 , back wall 34 and a side wall 35 . A slot 38 is cut into the front wall and extends from the opening 36 to past the halfway point of the circular base 30 . The pocket 37 is appropriately sized, height and width, to receive the suction cup 12 and flange 13 to create a frictional fit. The slot 38 is of sufficient size to accommodate the screw mount 14 . In the disclosed embodiment, the stand portion 2 fits in the base 30 with sufficient friction fit to prevent small movements or gravity from dislodging the stand portion 2 from the base 30 .
An adjustable torso strap 31 is comprised of a male strip 39 having a male clip 40 on one end and female strip 41 having a female clip 42 on one end. The other end of the male strip 39 is attached to the edge of base 30 at approximately the lateral axis 47 of the base. The other end of the female strip 41 is attached to the edge of base 30 at approximately the lateral axis 47 of the base 30 , on the opposing side of where the male strip 39 attaches to the base 30 . The male clip 40 corresponds to the female clip 42 and capable of locking. Other fasteners such as clips may be utilized.
An adjustable neck strap 32 is comprised of a right strip 43 having a hook and loop fastener 44 on one end and left strip 45 having a hook and loop fastener 46 on one end. The other end of the male strip 43 is attached to the back wall 34 of base 30 above the slot 38 . The other end of the female strip 45 is attached adjacent to the where the male strip 43 attaches to the base 30 on the opposite side of the longitudinal axis 48 of base 30 . The hook and loop fasteners 44 , 46 are capable of attaching to one another and securing the right strip 43 with the left strip 45 . Other fasteners such as clips may be utilized.
In operation and attached to a user as seen in FIGS. 6 and 7 , the back wall 34 of the base 30 is placed against a person's chest or torso 49 . The torso straps 39 , 41 are positioned around the person's torso 49 and connected through the clips 40 , 42 . The neck straps 43 , 45 are moved from the base 30 to extend behind the person's neck 50 and fastened with the hook and loop 44 , 46 . The torso strap 31 is to keep the base 30 against the person's torso 47 and the neck strap 32 is to assist in keeping the base 30 from moving up and down. The stand 2 is then inserted into the pocket 37 . An electronic device 20 is attached to the device holder 3 and the person may then use the pivot joint 9 , the telescoping element 7 , an/or the ball and socket joint 16 to adjust the device holder 3 to ensure proper use of the electronic device while keeping their hands free for other activities.
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An apparatus for holding electronic devices within view of a user without having to utilize the user's hands. The apparatus comprises a wearable base that extends around a user's torso and/or neck. A stand that comprises a frame, device holder and attachment member that is releasably attached into the base. The stand is capable of maneuvering the device through all range of motion to assist user in the viewing of the device without hands.
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This is a continuation of application Ser. No. 89,712, filed Oct. 30, 1979, now U.S. Pat. No. 4,320,403.
BACKGROUND OF THE INVENTION
Position finding with radar is widely used, particularly in fog and other low-visibility weather conditions. It is desirable, particularly at sea, to be able to recognise even small objects (for example rescue islands, small boats, etc) at a range of up to about 10 km. However, position finding is complicated in heavy seas because water alone provides a relatively high reflection (approximately 50%) of radar waves. Accordingly, the objects in question are required to have a reflective power of at least 90%. In many cases, compact materials which reflect radar beams with minimal losses cannot be used for external applications. For technical or weight reasons, the outer wall of small objects at sea cannot be provided with a compact metallic surface.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the recognisability of relatively small objects by radar beams, particularly at sea, in the air and in the rescue field. It has now been found that the recognisability of objects by radar, particularly of small objects, is improved if metallised sheet-form textile materials are applied to the objects, the metal having been applied to the sheet-form textile material after activation thereof in a total metal layer thickness of from 0.02 to 2.5 μm by currentless wet-chemical deposition. In the context of the invention, sheet-form textile materials are understood to be woven fabrics, knitted fabrics and non-woven fabrics. The invention relates to the use of metallised sheet-form textile materials as a reflecting material for microwave and decimeter wave radiation.
Polarisation of the radiation reflected by stretched metallised fabrics may be utilised to facilitate or improve object recognition. By periodic stretching and relaxation, it is possible to obtain a pulsating polarisation of the reflected microwaves.
It is of particular advantage that even thin metal layers have a sufficiently high reflective power. The surface conductivity of the sheet-form textile materials is considerably higher than it would be had the same amount of metal been applied by vapour deposition. Their surface resistance, as measured in accordance with DIN 54 345 at 23° C./50% relative humidity, is of the order of or less than 1.10 2 Ω. It is surprising that even layer thicknesses in the region of skin depth still have a reflective power which would appear to be associated with the textile support. In the case of nickel layers for example, the skin depth is 0.27 μm at 3 GHz and 0.16 μm at 9 GHz.
The improved recognition even of small objects, achieved by the surface being covered at least partly by metallised sheet-form textile materials, increases safety, particularly at sea, in the air and in the rescue field.
One particular advantage of the use according to the invention is the lightness in weight and flexibility of the material. It may be attached to uneven surfaces and may be cut to any size. It is so light that the additionally applied material hardly affects the overall weight. It is a novel technique of increasing the reflective power of a non-metallic object for radar beams. The strength of the layer applied by currentless deposition is also higher than would be expected in the case of metal layer applied by vapour deposition. Further it is possible additionally to protect the metal layer by another protective layer applied for example by lacquering, lamination or coating. The reflective power is very high over a range of from 0.02 to 1000 GHz, i.e. over a considerably wider range than simply the "classical" radar range.
The sheet-form textile material may consist of cotton, polyacrylonitrile, polyamide, aramide, polyester, viscose, modacrylics, polyolefin, polyurethane, PVC either individually or in combination with one another. The metal layer applied by currentless deposition preferably consists of nickel, cobalt, copper, silver, gold, even in combinations or as an alloy.
The mesh width or crossing points of the weft and warp filaments of woven fabrics should be smaller than half the wavelength of the radiation to be reflected. It is preferred to use a sheet-form textile material of which the mesh width does not exceed one tenth of the wavelength. The reflection level is also governed by the form of the textile construction. Accordingly, an isotropic textile construction will be selected if the reflection is intended to be isotropic. Alternatively, it is possible, by applying tension, to obtain a looser, wider-mesh sheet-form textile material so that the microwave beams are partly polarised after reflection if the incident radiation is unpolarised or, where the incident radiation is linearly polarised, reflection is particularly high when the mechanical tension and the vector of the electrical field strength are vertically superposed on one another.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of two crossing fibers metallized according to the present invention; and
FIG. 2 is a schematic representation of parallel running filaments of a fiber thread metallized according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, a fiber 1 of polyacrylonitrile, polyamide or cotton, etc. has a coating 2 thereon including layer 2a formed by currentless wet chemical deposition additional, coating 2b formed by currentless wet chemical deposition and protection coating 2c. The coating 2a and 2b has a total thickness of 0.02 to 2.5 μm and is substantially equally thick around the fiber. Between the fibers there is no agglutination of the fibers.
In FIG. 2, fiber thread 3 includes filaments 4 each coated with a metallized coating 5 by wet chemical currentless deposition. Each filament 4 has the coating 5 therearound, but the filaments 4 are not flued, that is, there is no coalescing.
The invention is illustrated by the following Examples:
EXAMPLE 1
A woven fabric of 100% polyacrylonitrile filament yarn has the following textile construction:
Warp and weft: 238 dtex (effective) of dtex 220 f 96 Z 150, 38.5 warp filaments/cm and 27 weft filaments/cm;
Weave: twill 2/2;
weight: 155 g/m 2 .
It is immersed at room temperature in a hydrochloric acid bath (pH≦1) of a colloidal palladium solution according to German Auslegeschrift No. 1,197,720. After a residence time in the bath of up to about 2 minutes, during which it is gently moved, the fabric is removed and washed with water at room temperature. It is then immersed for about 1.5 minutes in a 5% sodium hydroxide solution at room temperature. The fabric is then washed with water at room temperature for about 30 seconds and subsequently introduced at room temperature into a solution consisting of 0.2 mole/l of nickel-II-chloride, 0.9 mole/l of ammonium hydroxide, 0.2 mole/l of sodium hypophosphite, into which ammonia is introduced in such a quantity that the pH-value at 20° C. is approximately 9.4. After only 10 seconds, the fabric begins to darken in colour through the deposition of nickel. After 20 seconds, the fabric floats to the top, giving off hydrogen gas, and even at this stage is completely covered with nickel. The material is left in the metal salt bath for about 20 minutes, removed, washed and dried.
During these 20 minutes, the material (dry weight 7.2 g) takes up about 3.1 g, i.e. approximately 40% by weight, of nickel metal. The rapid activatability and the high deposition of metal at room temperature are surprising. The nickel layer thickness on the fibre surface amounts to 0.77 μm.
Various sheet-form textile materials thickly coated with nickel were produced by the above-described process and the reflection losses between 2 and 25 GHz measured. The measuring process used is described for example in "Mikrowellenmeβtechnik" by H. Groll, F. Vieweg & Sohn, Brunswick, 1969, pages 353 et seq. The reflection loss is expressed in dB. To eliminate the effect of standing waves in the region before the object to be measured (interfacial reflection), a wide-band frequency-modulated radiation of constant power, for example 1.9 to 2.4 GHz, 7 to 8 GHz, is used.
______________________________________Nickel LayerThickness in Frequency range in GHzμm 1.9-2.4 7-8 11-12 22-24.8______________________________________0.08 2.9 2.6 2.2 3.20.10 2.4 2.4 2.2 2.70.13 1.9 2.0 2.0 2.90.19 1.3 1.5 1.5 2.10.29 1.1 1.4 1.4 1.90.38 1.0 1.3 1.3 1.80.79 0.7 1.1 0.9 2.3______________________________________
EXAMPLE 2
Reflection losses in dB on metallised sheet-form textile materials for oblique incidence:
The sheet-form textile materials used are the same as in Example 1; they are also coated with nickel in the same way as in Example 1. The incidence angle is 30°.
______________________________________Nickel layer Frequency range in GHzthickness in μm 7-8 11-12______________________________________0.08 1.0 1.20.10 1.5 1.10.13 1.1 1.00.19 0.4 0.40.29 0.4 0.40.38 0.1 0.1______________________________________
EXAMPLE 3
A coarse fabric woven from spun polyacrylonitrile fibres in linen weave with a large interval separating the crossing points between warp and weft filaments (1.5 mm gap between the two warp and weft filaments; 50.4 warp filaments/10 cm, 42.2 weft filaments/10 cm, L 1/1) shows a reduction in reflection power with increasing frequency.
______________________________________Nickel layerthickness in Frequency range in GHzμm 1.7-2.4 7-8 11-12 23-24.5______________________________________0.2 0.7 1.0 1.2 3.20.78 0.3 0.9 1.1 2.4______________________________________
Accordingly, dense fabrics are required for obtaining good reflection at short wavelengths.
EXAMPLE 4
Combination of two metal layers:
A sheet-form textile material corresponding to Example 1 is coated as described in that Example with 0.2 μm thick nickel layer. Immediately after washing, it is introduced still wet into a gold cyanide bath at 78° C. The gold bath based on potassium gold cyanide (gold content 4 g/l) is adjusted with ammonia to a pH-value of 10.5. After 20 seconds, a metal film with a gold-like shine has been deposited onto the shining nickel layer. Within 5 minutes, the gold layer thickness on the nickel-coated surface amounts to 0.2 μm. The reflection losses in dB for vertical incidence are as follows:
______________________________________ Frequency range in GHzLayer thickness in μm 1.7-2.4 23-24.5______________________________________0.2 Ni + 0.38 Au 0.3 0.8______________________________________
EXAMPLE 5
The reflection level depends on mechanical tensions.
Linearly polarised microwave radiation impinges vertically on a knitted fabric of an acrylonitrile copolymer on which a 0.75 μm thick nickel layer has been deposited. Line II shows the reflection losses in dB when the knitted fabric is not subjected to mechanical tension. Line I shows the losses in the event of tensile stressing (tension direction parallel to the E-vector).
______________________________________ Frequency range in GHz 1.7-2.4 7-8 11-12 23-24.5______________________________________ I 0.9 0.8 1.3 3II 2 1.3 2.6 6______________________________________
A periodic variation in the tensile stress leads to a periodic variation in the reflected microwave intensity. In this way, it is possible to considerably increase the recognisability of an object being sought by radar in surroundings which reflect isotropically or at least constantly as a function of time (sea emergency rescue service, friend-foe recognition, etc). Either linearly polarised radiation is used and the variation in intensity of the reflector evaluated or circularly polarised radar beams are used, in which case the reflected signal shows a periodic variation in the ellipticality of the polarisation which may be detected by an analyzer at the receiving end.
EXAMPLE 6
A polyethylene paper, i.e. a non-woven material of polyolefin fibres, is provided as described above with a nickel layer applied by currentless deposition. For a 0.4 μm thick nickel layer, the reflection losses in dB are as follows:
______________________________________Frequency range in GHz 7-8 11-12______________________________________ 1.5 0.9______________________________________
This metallised sheet-form textile material is particularly suitable for use as a recognition material, for example in the form of a cross for searching helicopters. By virtue of its light weight, it may be conveniently be taken on expeditions.
EXAMPLE 7
A blended polyester/cotton fabric consisting of 65% by weight of polyester staple fibres based on polyethylene terephthalate and 35% by weight of cotton shows the following reflection losses in dB for a 0.7 μm thick nickel layer:
______________________________________Frequency range in GHz1.7- 2.4 7-8 11-12______________________________________0.7 0.7 0.7______________________________________
This metallised material is suitable for tents, rucksacks or articles of clothing for skiers and walkers. The weight of the fabric is only negligibly increased by metallisation; it does not lose any of its textile-elastic properties. If it is coated with a layer of flexible PVC to make it rainproof, it may additionally be provided with warning colours. Persons carrying rucksacks or wearing articles of clothing such as these can be located by radar should they lose their way in desert regions or in the tundra.
EXAMPLE 8
A balloon fabric, for example of a woven polyester filament yarn fabric or woven nylon-6,6 fabric, is coated with an approximately 0.7 μm thick nickel layer applied by currentless deposition. In addition, it is given a protective coating of PVC, rubber or polyurethane lacquer. This subsequent lamination does not affect the reflective power of the sheet-form material. Line I shows the reflection losses in dB of this fabric when it is only coated with a 0.7 μm thick nickel layer. Line II shows the losses with an additional rubber coating.
______________________________________ Frequency range in GHz 1.9-2.4 7-8 11-12 22-24.5______________________________________ I 0.6 1.2 0.7 1.6II 0.7 1.2 0.8 1.6______________________________________
A free balloon made of a material such as this may readily be located by the on-board radar of a commercial aircraft.
In the construction of gliders, the fabric may also be embedded as the last layer in polyester resin which increases the radar locatability of gliders.
EXAMPLE 9
The use of metallised laminated fabrics in the rescue field is in accordance with the following:
A woven polyamide or polyester filament yarn fabric is provided with an approximately 0.65 μm thick nickel layer. Line I of the following Table shows the reflection losses in dB. Lamination with a PVC-coating (line II) or with a polyethylene coating (line III) hardly affects the reflective power of the metallised fabric.
______________________________________Frequency range in GHz1.8-2.4 7-8 11-12______________________________________ I 0.5 0.8 0.8 II 0.5 0.5 0.8III 0.5 0.5 0.9______________________________________
Life jackets may advantageously be produced from this metallised fabric and may additionally be coated with the prescribed warning paint RAL 2002. The fabric may also be used on rescue islands. When the fabric is applied to the mast tops of sailing boats, the boats are easier to locate by radar without being made top-heavy.
Another advantage of the metallised sheet-form materials is that they may be electrically heated.
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Metallized sheet-form textile materials of synthetic polymers or natural fibres, to which a metal layer has been applied by currentless wet-chemical deposition, are particularly suitable for use as reflectors for electromagnetic waves in the range from 10 MHz to 1000 GHz. In the case of stretched metallized fabrics, the reflecting radiation is partly polarized which can facilitate or improve the recognition of an object by radar beams. By periodically stretching and relaxing the fabric, it is even possible to modulate the reflected microwaves.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a semiconductor laser driving apparatus, and more particularly to a semiconductor laser driving apparatus useful in an optical disk recording and reproducing system wherein information is recorded on and reproduced from a optical disk such as a magnetooptical disk.
2. Description of the Prior Art
In an optical disk recording and reproducing system, information is recorded in and reproduced from an optical disk such as a rewritable type magnetooptical disk. Hereinafter, description will be made, taking a rewritable type magnetooptical disk as a typical example of an optical disk. However, the invention can be also applicable to a semiconductor laser driving apparatus for an optical disk of another type such as a write-once type one or phase-transition type one.
When information is to be recorded on or erased from a magnetooptical disk comprising a magnetic thin film, a high power laser light beam is irradiated onto the disk to elevate locally the temperature of the magnetic thin film which has been perpendicularly magnetized, thereby causing the magnetization of the magnetic thin film to invert in the direction of an external magnetic field. In contrast, when information is to be reproduced from the magnetooptical disk, a low power laser light beam is irradiated to the disk to detect the variation in a reflected light beam polarization which corresponds to the state of the magnetization of the magnetic film. Hence, an optical disk recording and reproducing system is provided with a semiconductor laser driving apparatus which supplies a driving current to a semiconductor laser device the level of which is controlled in accordance with the operating modes of the system (i.e., the recording and erasing mode or the reproducing mode).
FIG. 7 shows a prior art semiconductor laser driving apparatus. In the reproducing mode, a switch circuit 21 is closed by the reproduction ON signal. Then, the output of an operational amplifier 22 to which a power source V ref is connected via the non-inverting input, is supplied to a transistor Tr to turn it ON, thereby a reproduction driving current I R is supplied to a semiconductor laser device 23 to emit a laser light beam. The laser light beam is monitored by an optical detecting element 24 such as a photodiode so that a signal, the level of which corresponds to the power of the laser light beam, is supplied to the inverting input of the operational amplifier 22. This negative feedback enables the transistor Tr to control the reproduction driving current I R so that the power of the laser light beam emitted from the laser device 23 is maintained to a predetermined level.
Because the optical output level of the semiconductor laser device 23 is influenced by the change in temperature, it is not sufficient for maintaining the output power of a laser light beam at a fixed value to control the reproduction driving current I R at a constant level. This will be described in more detail, with reference to FIG. 8. When the temperature changes, the I-P (driving current-optical output power) characteristic of the semiconductor laser device 23 greatly changes, for example, from curve A to curve B. In accordance with curve A, a fixed optical output level P R can been obtained by supplying a reproduction driving current I R1 to the laser device 23. When the temperature rises, the I-P characteristic of the laser device 23 changes as shown by the curve B, resulting in that a greater reproduction driving current I R2 is necessary for obtaining the optical output level P R . In order to maintain the optical output level P R at a constant level, therefore, the reproduction driving current I R2 must be controlled while monitoring the optical output level P R .
When the recording and erasing mode is set, the reproduction driving current I R is fixed to a level which is same as the one at the time immediately before setting the mode, by a sample hold circuit (not shown). A record and erasing signal circuit 25 produces a recording and erasing signal. In accordance with the recording and erasing signal, another switch circuit 26 is closed or opened. When the switch circuit 26 is closed, a record and erase driving current I W flows through the semiconductor laser device 23 while being superposed on the reproduction driving current I R . Consequently, when information is recording, the laser light beam emitted from the laser device 23 is modulated in accordance with information to be recorded. When information is erasing, the switch circuit 26 remains to be closed to allow the record and erase driving current I W to flow through the laser device 23.
The amount of the record and erase driving current I W changes in accordance with the resistance value of the resistor circuit 28 which is selected by a selection circuit 27. The selection circuit 27 has four switches which can be selectively closed or opened in response to a selection signal supplied from an optical output power selection signal circuit 29. The resistor circuit 28 has four resistors R 1 to R 4 which have a different resistance value and are respectively connected in parallel to the four switches of the selection circuit 27. The selection signal circuit 29 detects the position of an optical disk on which the laser light beam of the laser device 23 is irradiated, i.e., the distance between this position and the center of the disk (hereinafter, such a position is referred to as "an irradiated position"), and produces the selection signal which corresponds to the detected position. The signal circuit 29 produces the selection signal so that the level of the record and erase driving current I W becomes greater as the irradiated position moves outwards (i.e., towards the outer periphery of the disk).
The reason why the level of the record and erase driving current I W changes in accordance with the irradiated position is that, when an optical disk rotates at a constant angular velocity, the linear velocity of the irradiated position becomes faster as the irradiated position moves outwards. In other words, in order that the energy of the laser light beam given to the magnetic thin film is kept constant regardless of the irradiated position, it is necessary to increase the optical output power of the laser light beam as the irradiated position moves outwards. The resistors R 1 to R 4 are selected by the selection circuit 27 so as to increase stepwise the record and erase driving current I W as the irradiated position moves outwards.
A semiconductor laser driving apparatus having such a configuration is described in the Japanese Laid-Open Patent Publication (kokai) No. 62(1987)-257,640.
Thus, in a conventional semiconductor laser driving apparatus, the level of the record and erase driving current I W which is superposed on the reproduction driving current I R is always constant as far as the irradiated position remains still.
As mentioned above, the I-P characteristic of the semiconductor laser device 23 changes when the temperature rises. The change of the I-P characteristic due to the temperature change is not a mere shift of the characteristic curve (e.g., from curve A to curve B' as shown in FIG. 8), but is one which includes the change in the slope of the characteristic curve (e.g., from curve A to curve B as shown in FIG. 8). When the I-P characteristic is changed from curve A to curve B, the differential efficiency is reduced from ΔP X1 /ΔI W to ΔP X2 /ΔI W . If, according to the characteristic curve A, a predetermined optical output level P X1 has been obtained by superposing the record and erase driving current I W on the reproduction driving current I R1 , the temperature rise causes the laser device 23 to operate in accordance with curve B, resulting in that the optical output reaches only the output level P X2 , even when the record and erase driving current I W is superposed on a reproduction driving current I R2 which maintains the optical output level P R for the reproduction at a constant value. This is caused by the reduction in the optical output of the laser device which is due to the decrease in the differential efficiency. When the temperature falls, conversely, the optical output level of the laser device 23 may be excessively increased.
In this way, a prior art semiconductor laser driving apparatus cannot cope with the change in the differential efficiency of the I-P characteristic of a semiconductor laser device, and has a drawback that it cannot control the laser device to emit the laser light beam having the optimum power.
As the differential efficiency may differ depending upon individual semiconductor laser devices even at the same temperature, a prior art semiconductor laser driving apparatus has another drawback in that the combinations or resistance values of the resistors R 1 to R 4 in the resistance circuit 28 need to be initially adjusted for each apparatus.
The above-mentioned drawbacks are generally applicable to a semiconductor laser driving apparatus for other optical disk systems including those for a write-once type optical disk.
SUMMARY OF THE INVENTION
The semiconductor laser driving apparatus of this invention, which overcomes the above-discussed and numerous other disadvantages and deficiencies of the prior art, supplies a driving current to a semiconductor laser device of an optical disk recording and reproducing system, the level of which is changed to adjust the optical output of the semiconductor laser device to one of plural levels corresponding to positions of an optical disk which is irradiated by a laser beam emitted from said laser device, and comprises: a current supplying means for sequentially supplying plural reference driving currents having a different level to said laser device; a monitoring means for detecting the optical output level of said laser device when each of said reference driving currents is supplied to said laser device; a setting means for setting several optimum values on the basis of the detected optical output levels; and a selecting means for selecting one of said several optimum values, depending upon the position of an optical disk where is to be irradiated by a laser beam.
In a preferred embodiment, the current supplying means supplies a driving current corresponding to said selected optimum value for recording and erasing information.
In a preferred embodiment, the first current supplying means supply three or more kinds of reference driving currents before supplying said driving current for recording information.
In a preferred embodiment, the level of each of said three or more kinds of reference driving currents is gradually increased.
In a preferred embodiment, the first current supplying means supply two kinds of reference driving currents before supplying said driving current for recording information.
Thus, the invention described herein makes possible the objectives of (1) providing a semiconductor laser driving apparatus which can control a semiconductor laser device to emit a laser light beam of a desired power even when the temperature changes; and (2) providing a semiconductor laser driving apparatus in which it is not necessary to initially adjust the current limiting means such as resistors.
The driving currents may be supplied in such a manner that the level of each of the driving currents change step by step. The setting means may compare one by one the optical output levels monitored by the monitoring means with predetermined optical output levels which correspond to irradiated positions, respectively, and, when they substantially coincide with each other, a value corresponding to the driving current is set.
If the I-P characteristic of a semiconductor laser device can be deemed to be substantially linear, it may be sufficient to supply only two kinds of the driving currents the values of which are sufficiently different from each other. In this case, two optical output levels caused by the two driving currents are detected to form a line which represents the I-P characteristic of the laser device. Values corresponding to driving currents for generating a laser light beam of a predetermined optical output level can be set from the line.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings as follows:
FIG. 1 is a block diagram showing a semiconductor laser driving apparatus of the invention.
FIG. 2 is a diagram for illustrating an example of the relationship between irradiated positions and optical output levels.
FIG. 3 is a flow chart of a first example of the automatic setting of digital data.
FIG. 4 is a graph of the I-P characteristic curve in the automatic setting of digital data shown in FIG. 3.
FIG. 5 is a flow chart of a second example of the automatic setting of digital data.
FIG. 6 is a graph of the I-P characteristic curve in the automatic setting of digital data shown in FIG. 5.
FIG. 7 is a circuit diagram of a conventional semiconductor laser driving apparatus.
FIG. 8 is a graph of the I-P characteristic curve in the apparatus of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a semiconductor laser driving apparatus according to the invention. In the apparatus of FIG. 1, a semiconductor laser device 1 is driven by the reproduction driving current I R supplied from a reproduction current source (V/I) 2, and also by the record and erase driving current I W supplied via a switch circuit 4. The laser light beam emitted from the laser device 1 is monitored by an optical detecting element 5. The output of the optical detecting element 5 is supplied to an automatic power control (APC) circuit 7 through an I/V converter 6. The output of the APC circuit 5 is supplied to the reproduction current source 2 to form a loop for feedbacking the optical output level of the laser device 1, thereby enabling the laser device 1 to generate the optical output level P R for the reproduction having a predetermined value.
The output of the I/V converter 6 is also connected to an A/D converter 8 which converts the optical output level detected by the optical detecting element 5 into digital data D in . The digital data D in is supplied to a CPU 9. The CPU 9 to which a ROM 10 and RAM 11 are connected produces digital data D out to supply it to a D/A converter 12. The D/A converter 12 converts the digital data D out into a voltage value which is supplied to a record and erase driving current source (V/I) 3. Consequently, the CPU 9 can monitor the optical output of the laser device 1 generated when the record and erase driving current I W is supplied to the laser device 1.
To the control input of the switch circuit 4, the output of a record and erasing signal circuit 13 is connected so that the switch circuit 4 is closed or opened according to the record and erasing signal supplied from the circuit 13. When the switch circuit 4 is closed, the record and erase driving current I W is supplied to the laser device 1. When the recording and erasing mode is set, the reproduction driving current I R is fixed to a level which is same as the one at the time immediately before setting the mode, by a sample hold circuit (not shown). The record and erase driving current I W flows through the semiconductor laser device 1 while being superposed on the reproduction driving current I R .
The ROM 10 stores five digital data D P1 to D P5 (D Px ) which correspond respectively to predetermined optical output levels P 1 to P 5 (P x ). As shown in FIG. 2, these predetermined levels P 1 to P 5 (P x ) indicate the optimum optical output levels of the laser device 1 at each of the irradiated positions in the recording and erasing operation by the semiconductor laser element 1. Namely, the laser device 1 emits a laser light beam of the optical output level P 1 when the irradiated position is in the range between radius r 1 and radius r 2 of an optical disk, a laser light beam of the optical output level P 2 when the irradiated position is in the range between radius r 2 and radius r 3 , and a laser light beam of the optical output level P 5 when the irradiated position is in the range between radius r 5 and radius r 6 . These predetermined levels are selected so that the optical energy supplied to the medium of the optical disk is optimum when the laser light beams of such levels impinge on the respective irradiated position.
The RAM 11 stores five digital data D Xout which respectively correspond to five levels of the record and erase driving current I W for obtaining the five kinds of the optical output levels P X . The CPU 9 selects one of the digital data D Xout in accordance with the present irradiated position, and read it out from the RAM 11. The selected one of the digital data D Xout is supplied as the digital data D out to the record and erase driving current source 3 so that the laser device 1 emits a laser light beam of the optimum optical power level P X .
In the preferred embodiment, the digital data D Xout are automatically set according to the temperature conditions and the I-P characteristics of the semiconductor laser device 1, preferably, immediately before the recording and erasing operation. Two examples of the manner of modifying the digital data D Xout will be described.
FIG. 3 shows the flow chart of the first example. In this example, the automatic setting of the digital data D Xout is performed immediately before the recording and erasing operation. In step S1, a loop counter X is set to one, and the digital data D Sout is initialized to the data D IW=0 which is selected so that, when it is supplied to the record and erase driving current source 3 via the D/A converter 12, the record and erase driving current I W becomes zero. In this step, therefore, the semiconductor laser device is driven only by the reproduction driving current I R to generate a laser light beam of the level P R , as shown in FIG. 4.
Thereafter, the digital data D Sout is incremented by one level (step S2). The degree of this increment of this one level has been set to a value which is so small that it is within the permissible range of fluctuation within the optical output level of the laser light beam emitted from the laser device 1. This digital data D Sout is sent to the driving current source 3 via the D/A converter 12, thereby supplying the record and erase driving current I W the level of which corresponds to the digital data D Sout . The CPU 9 receives digital data D Sin from the A/D converter 8 (step S3).
The CPU 9 compares the digital data D Sin with the digital data D P1 (D PX ) stored in the ROM 10 (step S4). When the digital data D Sin is less than the digital data D P1 , the operation returns to step S2 to repeat the above-mentioned processes.
When the digital data D Sin reaches the digital data D P1 as a result of the gradual increases of the digital data D Sout by repeating step S2, the value of the digital data D Sin with the digital data D P1 at this time is set in the RAM 11 as digital data D 1out (D Xout ) (step S5). This will be described in more detail with reference to FIG. 4. With the gradual increase of the digital data D Sout , the record and erase driving current I W is increased by the step of ΔI W to increase the optical output P by the step of ΔP. When the optical output P becomes equal to or greater than the predetermined optical output level P 1 , the digital data D Sout corresponding to the record and erase driving current I W at this instant (i.e., the record and erase driving current I W1 ) is set as the digital data D 1out (D Xout ) in the RAM 11.
After the digital data D Xout is set, the loop counter X is incremented by one (step S6), and it is checked to see whether the loop counter X exceeds five or not (step S7). When the loop counter X is less than five, the operation returns again to step S2 to repeat the processes. When the loop counter X reaches five (i.e., all the digital data D 1out to D 5out (D Xout ) have been set in the RAM 11), the automatic setting of the digital data D Xout has been completed.
After the automatic setting of the digital data D Xout has been completed, the apparatus starts the recording and erasing operation on the basis of the newly set digital data D Xout .
The second example of the automatic setting of the digital data D Xout will be described with reference to FIGS. 5 and 6. Also in this example, the automatic setting of the digital data D Xout is performed immediately before the recording and erasing operation. The CPU 9 sends digital data D Aout to the driving current source 3 via the D/A converter 12, thereby supplying the record and erase driving current I WA the level of which corresponds to the digital data D Aout . As shown in FIG. 6, the digital data D Aout is a value corresponding to the record and erase driving current I WA for generating a laser light beam of the optical output level P A which is previously set within the range from P min to P max . In this range from P min to P max , the I-P characteristic curve of the semiconductor laser device 1 is substantially linear. The laser device 1 is driven by the reproduction driving current I R on which the record and erase driving current I WA is superposed, to emit a laser light beam of the optical output level P A . The optical output level P A is detected by the I/V converter 6 to be input as digital data D Ain (step S12).
Then, the CPU 9 sends data D Bout to the driving current source 3 via the D/A converter 12, thereby supplying to the laser device 1 the record and erase driving current I WB the level of which corresponds to the digital data D Bout (step S13). The optical output level P B is previously set so that it is sufficiently greater than the optical output level P A in the linear range. The laser device 1 is driven by the reproduction driving current I R on which the record and erase driving current I WB is superposed, to emit a laser light beam of the optical output level P B . The optical output level P B is converted by the A/D converter 8 to be input as digital data D Bin (step S14).
After the digital data D Ain and D Bin have been input, the loop counter X is set to one (step S15), and the operation enters into the loop of setting digital data D Xout (steps S16 to S18). In this loop, a digital data D 1out is calculated from the digital data D Ain and D Bin , as described later, and the obtained digital data D 1out is set in the RAM 11 (step S16). The loop counter X is incremented (step S17), and the loop counter X is checked to see whether it is greater than five or not (step S18). When the loop counter X is not greater than five, the operation returns to step S16 to repeat the processes. When the loop counter X reaches five, in other words, all the digital data D 1out to D 5out (D Xout ) have been set in the RAM 11, the automatic setting of the digital data D Xout terminates.
In step S16, the digital data D 1out to D 5out (D Xout ) are calculated by the following expression, respectively for X of 1 to 5. ##EQU1## where the term "(D BOUT -D AOUT )/(D BIN -D AIN )" means "(I WB -I WA )/(P B -P A )", i.e., the reciprocal of a differential efficiency in the I-P curve. The symbol "D PX " represents the digital data which correspond respectively to predetermined optical output levels P X shown in FIG. 2, and the symbol "D PR " represents the digital data corresponding to the optical output level P R for the reproduction mode. Therefore, the term "(D PX -D PR )" means (P X -P R ) or the optical output level which is to be superposed on the optical output level P R for the reproduction mode in order to obtain the optical output level P X for the recording and erasing mode. Summarizing the above, the right side of the expression is the multiplication of (P X -P R ) and the reciprocal of a differential efficiency, thereby obtaining the digital data D Xout corresponding to the record and erase driving current I WX which should be superposed to the reproduction driving current I R .
The initial digital data D IW-0 may be used as the digital data D Aout produced in step S11. In this case, the record and erase driving current I W becomes zero so that the optical output level P A coincides with the the reproduction driving current I R in the reproduction mode.
Also in this example, after the automatic setting of the digital data D Xout has been completed, the apparatus starts the recording and erasing operation on the basis of the newly set digital data D Xout .
It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains.
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A semiconductor laser driving apparatus for supplying a driving current to a semiconductor laser device of an optical disk recording and reproducing system, the level of which is changed to adjust the optical output of the laser device to one of plural levels corresponding to positions of an optical disk which is irradiated by a laser beam emitted from the laser device. The apparatus comprises: a current source for sequentially supplying plural reference driving currents having a different predetermined level to the laser device; a monitor for detecting the optical output level of the laser device when each of the reference driving currents is supplied to the laser device; a setting device for setting several optimum values on the basis of the detected optical output levels; a selecting device for selecting one of the several optimum values, depending upon the position of an optical disk where is to be irradiated by a laser beam; and said current source for supplying a driving current for recording information on an optical disk, to the laser device, the level of the driving current corresponding to the selected optimum value.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a comprehensive, uniform, retrofit, commercial and institutional kitchen grease removal and bioremediation system.
2. Description of Prior Art
In as much as grease residue is a by-product of certain forms of cooking, it is naturally understandable that numerous attempts have been made to address the myriad of problems associated with the accumulation of grease in higher volume commercial kitchens:
One area where grease buildup and its removal is most problematic is the exhaust hood, flue, roof surface adjacent to and surrounding the flue, and the kitchen drain lines and grease trap. Grease buildup in these areas is particularly critical in as much as it undermines the sanitary environment of the kitchen, increases the hazard of uncontrollable fires, generates foul odors, promotes insect and rodent infestation and is ultimately the primary cause of sewer stoppage. The generally accepted procedure for dealing with the exhaust hood grease problem is by manual periodic cleaning of the exhaust system when grease accumulations reach unacceptable levels. Grease is removed either manually with scrapers by the kitchen staff or by professional companies using steam and/or power spray washing equipment. In either case, the cleaning is usually done during off hours as it is an incredibly filthy and disruptive process. Handling the waste is a subsequent problem. Invariably, a good portion of the oily effluent ends up in the grease trap via the floor drains. This sudden surge in the volume of grease being discharged into the trap creates additional problems. These will be addressed later. However, the additional volume of greasy sludge shortens the intervals in the pumping (emptying) schedule for the grease trap and increases the frequency of clogged waste lines. The balance of the residue, if properly collected and contained must be disposed of, which, even in the best case scenario remains waste that is hazardous to the environment. An additional problem associated with manual or high pressure cleaning is the increased risk of possible inadvertent contamination of foodstuffs, utensils, and food prep surface areas resulting from failure to contain contaminates being carried in high volumes of water, airborne under pressure.
To avoid the many complications associated with this unpleasant manual procedure, various attempts have been made to devise automatic or self-cleaning hoods, which utilize permanent or removable tortuous air path baffle filters of various designs to catch the grease for removal by water spray. These vent hood systems are expensive and, regardless of their effectiveness, do nothing for the existing facility that cannot justify the complete replacement of a sound, fully functioning, conventional exhaust hood. Other pipe systems utilize fixed or rotating nozzle apparatuses extending along the axis of the exhaust duct (flue) and rely on the impingement of water spray under high pressure to remove grease buildup. Yet other systems are designed with elaborate pipe spray manifolds on wheels that are raised and lowered through the exhaust duct by pulleys and cables and provide coverage to the inside surface of the duct at terrific pressure. The intent is obviously to remove thick encrusted grease and sludge. That these systems utilize a relatively high volume of water in their operation is undeniable. One system in particular uses hot water in the cleaning process. Couple the cost of the water with the energy cost of heating it and it would only seem prudent to activate the system as infrequently as possible. A protracted cleaning schedule allows the daily accumulation of grease to build into the encrusted sludge these systems are obviously designed to address. Furthermore, the infrequent cleaning cycle and high volume of water produces the same waste disposal problems to contend with as the manual method previously discussed.
As with the self-cleaning hoods, it is apparent that these mechanical spray systems would most likely operate at optimum levels when installed in an exhaust duct tailored to be specifically compatible with the washing fixture. Otherwise, the washing fixture would have to be custom designed for each individual duct size and configuration. There seems to be a limitation in their utility in retrofit installations as universality is not apparent.
A search of prior art reveals several power spray washing systems for use inside confined areas such as tanks, pipes and exhaust systems. However, no system is found that provides thorough coverage of solution to adjacent surfaces at pressures less than 20 PSI and volumes as little as one-third gallon per minute. Additionally, no system was discovered that could be installed easily in retrofit and function universally well in a broad array of enclosure configurations having varying dimensions.
Regardless of the effectiveness of the various exhaust system washing devices, they commonly have no impact whatsoever on the grease that collects in and on the inside and outside surfaces of the exhaust fan unit typically mounted at the top of the flue. These grease accumulations generally drain downward from the exhaust fan and pool on the surface of the roof. This condition is undesirable in that, in addition to the obvious fire hazard, it sustains and promotes foul odors and ultimately undermines the integrity of most roofing systems. Hydrocarbons dissolve asphaltic roofing compounds and dramatically shorten roof life. The aspect of preparing or replacing a costly 10-year roofing system in 2 to 5 years is a sobering consideration indeed.
As with the exhaust washing systems, there are most certainly various prior art attempts at a solution to this problem. The exhaust fans have been fitted with collection buckets located below drainage holes drilled in the low point of the fan shroud. The grease that collects in the fan shroud drains through the hole and collects in the bucket below. These buckets require emptying on a regular basis or the grease overflows right back on the roof. Also, this approach does nothing to stop grease from flowing out between the base of the exhaust fan and the top of the flue to join the other grease accumulated on the outside of the fan itself on its downward flow to the roof.
Another prior art solution is to mount a gutter on the outside of the exhaust fan base skirt, which collects a portion of the grease in an integral box mounted on the gutter which is designed to separate grease and rainwater. Like the bucket solution, the collector box must be emptied manually or the grease overflows back onto the roof. Due to broad tolerances being acceptable in building practice, many exhaust flues are built to the exact size of the fan base, or out of square. Either situation leaves little or no free space between exhaust fan base skirts and flue housings for additional flashing components. For this reason, the gutter was designed to mount on the outside of the fan base skirt. Like other collectors, this design does not address the grease that flows outward between the top of the flue and the base of the exhaust fan.
Yet another attempt at addressing the problem has been to build a sand box on the roof surface surrounding the exhaust flue housing to collect the grease prior to its coming into contact with the roof. The ramifications of taking this approach are obvious in that oil and grease are lighter than water, therefore rain floats the grease out on the roof.
A more sophisticated prior art version of the sand box approach comprises an aluminum frame which lays on the roof surface and surrounds the flue housing containing a disposable fiber mesh trap type filter element which is intended to collect and retain the grease to the point of saturation and then be replaced. It would seem that a fiber filter saturated with flammable grease could be considered to have the properties of a wick waiting to be fired. This approach proves to be costly in as much as the filter elements and labor to replace them are not inexpensive.
The effectiveness of all prior art attempts reviewed that deal with the collection of grease is contingent on the timely emptying of the receptacle when full. Other than focusing primarily on keeping grease off the roof to some degree, these systems do little to address the other problems associated with roof top grease including but not limited to fire hazards, rodent and insect infestation, foul odors associated with putrefying grease, and ultimately the final disposition of the grease itself.
Numerous prior art examples have been found that trap and treat grease with enzymes and/or bacterial spores. No doubt, various systems are effective to some extent in reducing the discharged volume of grease deposited in them.
Some prior art deals with the manual introduction of microbes into the sewer drain lines and grease traps of commercial kitchens. More specifically, floor drain covers are repaired to preclude foreign matter from entering the drain lines and microbes are introduced. However, this is a manual process which is obviously done on a periodic schedule. In as much as it is difficult to eliminate the use of cleaners and other chemicals including but not limited to chlorine, which is toxic to microbial life, in the day-to-day operation of a food service facility, the effectiveness of infrequent treatment is easily undermined. The only possible way of assuring enhanced bioremediation is through the daily metered injection of fresh, healthy hydrocarbon-specific microorganisms into the primary floor drain lines and grease trap. No known system exists specifically designed for this purpose.
SUMMARY OF THE INVENTION
None of the prior art grease trap devices, being primarily of singular purpose in their design, offer an intentional multiplicity of functions beginning with A. A controlled environment designed specifically for the enhanced and sustained on-site (point of use) propagation of cultured hydrocarbon specific microflora. B. Capable of cycling large volumes of rainwater through the system without purging or flushing the high or low gravity liquid out of the system. C. Support an integral systematic recirculating pressure cleaning apparatus. Nor has any device been discovered that in addition to collectively integrating and providing all the systematic functions listed in A, B and C, also D. Acts as a cleaning solution reclaimer, rejuvenator and recycler and E. Systematically inoculates the sewer drain lines and primary grease trap automatically on a timed daily basis from a never ending perpetual supply of on-site propagated hydrocarbon-specific microorganisms to ultimately reduce the total volume of grease waste accumulated from cooking operations that is discharged into the sewer system. In as much as microbiological treatment of hydrocarbon waste has proven to be advantageous it has also been established that microorganic life itself is vulnerable to a broad spectrum of toxic chemicals and less than ideal environmental conditions. For this reason, the accepted practice for the food service industry is to manually charge grease traps and/or drain lines monthly to re-establish microbe colonies being killed daily by toxic chemicals being discharged into the grease traps via the sewer system usually stemming from mopping, dish-washing and other cleaning operations. The standard procedure involves culturing hydrocarbon specific microorganisms in a laboratory and then bringing the culture to the point of use for manual introduction into the target system, thereby replenishing the microflora periodically. However, microbes are quite prolific given an ideal environment conducive to enhanced propagation. Therefore, an on-site system that by design cannot be purged by large volumes of flowing water, is not subjected to contaminates by being located in line with sewer waste water and is climatically stable seems needed and at this point unavailable.
The object of this invention deals with a comprehensive process for the timed systematic collection and bioremediation of kitchen grease that begins with the retrofit installation in a commercial kitchen of an integrated system of technology that includes:
a. A bio-reactive fluid reclaim unit comprised of a series of tanks, pumps, filters, timer, solenoid valves, float valves, contactors, heat elements, T-stats and the necessary wiring harnesses and fluid connectors to facilitate its operation.
b. A universally adaptable low volume, low pressure spray boom assembly, comprising a piping system and rotary spray nozzles designed to operate at pressures of 20 PSI or less and volumes as low as one third gallon per minute.
c. A baffle system, for universal retrofit installation in commercial kitchen exhaust hoods that, in addition to allowing free air passage and collecting the fall back grease as traditional baffles do, also prohibits the passage of aqueous splatter as might result from the cleaning cycle.
d. A fluid return sump assembly, and optional universal hood gutter, to collect washing fluid and hydrolyzed grease residue resultant of a cleaning process.
e. An automatic fluid return sump assembly, and related piping system to return the washing fluid and hydrolyzed grease residue to the Bio-reactive fluid reclaim unit.
f. A makeup solution injector reservoir, containing a microbe reserve and supply of PH neutral surfactant/disbursant/oxidizing solution for timed and metered daily injection into the system via the fluid return sump assembly.
g. A fluid collector manifold/fan mount adaptor, that mounts on top of the flue above the roof line between the flue and the base of the exhaust fan.
h. A drain line, connecting the gutter/manifold to the circulation/bioremediation unit.
i. A drain line, connecting the bio-reactive, fluid reclaim unit to the nearest plumbing waste vent or vents common to the kitchen floor drain system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the system incorporating the present invention.
FIG. 2 is a top view of the bioremediation unit.
FIG. 3 is an elevational view of the bioremediation unit.
FIG. 4 is a perspective view of the fluid collector/fan mount adaptor.
FIG. 5 is an elevational view of the fluid return sump assembly.
FIG. 6 is a sectional view of the rotary spray nozzle.
FIG. 7 is an exploded view of the bearing for the rotary spray nozzle.
FIG. 8 is an exploded view of the baffle filter system.
FIG. 9 is an elevational view of vent hood, fluid return sump assembly and make up solution injector reservoir.
DETAILED DESCRIPTION
The complete bio-mechanical system is generally comprised of eleven major interrelated (integral) components including: A. a bio-reactive fluid reclaim unit 200, FIG. 1, 2, and 3, B. a fluid collector/fan mount adaptor manifold 36, FIG. 4, C. a universal low volume/low pressure spray boom assembly 23, FIG. 1, D. low volume rotary spray nozzles 24, FIGS. 1, 4 and 6, utilizing E. self-centering thrust-bearing 26, FIGS. 6 and 7, F. mist-blocking baffle filter system 600, FIGS. 1, 8 and 9, G. universal hood gutter system 700, FIGS. 1 and 9, H. a fluid return sump assembly 28, FIGS. 1, 5 and 9, I. a makeup solution injector reservoir 40, FIGS. 1 and 9, J. a wash fluid return-piping system 32, FIGS. 1, 5 and 9, K. and a bioremediation fluid discharge line 38, FIG. 1.
More specifically, bio-reactive fluid reclaim unit 200, as depicted in top view, FIG. 2 and end view FIG. 3 (electric control box omitted from FIG. 3 for clarity) is comprised of:
A common base plate 201 which serves as a mounting surface for circulation chamber or tank 202, receiver chamber or tank 203, discharge chamber or tank 204, electrical component control box 205, the main system pressure pump 226, fluid reclaim cycle suction solenoid valve 230, optional heat kit fan unit 199, and the primary common support and bottom attachment point for side cover panels 291, 292, 293, and 294.
Circulation tank or chamber 202 is fitted with fluid equalization port 212 common to receiver tank 203. Circulating tank 202 is also fitted with a first directional fluid flow discharge fitting 210, centrifuge fluid flow stratifier 208, cleaning cycle suction port 216, grease transfer wier or channel 206a common to discharge tank 204, a heat element receptacle 207a, a heat element 262a (to prevent freezing), and an air line inlet port (grommet) 266a.
Receiver tank or chamber 203 is likewise fitted with fluid equalization port 212 common to Circulation tank 202, the main system inlet port 213, a second directional fluid flow discharge fitting 211, centrifuge fluid flow stratifier 209, timed equalization port 218, grease transfer weir 206b common to discharge tank 204, a heat element receptacle 207b, a heat element 262b, and an air line inlet port (grommet) 266b.
Discharge tank or chamber 204 is fitted with 2 grease transfer weirs 206a and 206b common to tanks 202 and 203 respectively, fluid reclaim cycle suction port 215, timed equalization port 217, fluid agitation inlet port 219, spindown filter sediment discharge port 220, a heat element receptacle 207c, a heat element 262c, a thermostat mounting bracket 264, an airline inlet port (grommet) 266c, and the main system bio-remediation fluid discharge port 214.
Electrical component control box 205 is configured to accept wiring grommets 275, 276, 277, 278, and 280 respectively to facilitate installation of heat element, solenoid valve, pressure pump, air pump, and low voltage contactor wiring. Control box 205 internally houses control wiring distribution terminal block 272, a 24 hr. timer 273, a sub-process timer 274, and optional "fan kit" component/low-voltage transformer 279, heat element contactor 263c and optional heat kit fan contactor 285b. The exterior of control box 205 serves as a mounting surface for air-pump 265, air valve manifold 269, sediment discharge solenoid valve 254, wafer bi-metal snap disk thermostat 285c to control optional heat kit 285, spin down filter mounting bracket 221, main power inlet 270, and corresponding main power disconnect 271.
Other components in bio-reactive fluid reclaim unit 200 include those relative to fluid flow beginning with primary suction line 227a connecting main system pump 226 by way of vertical fluid reclaim cycle suction line "T" 228 to two separate fluid reservoirs, tank 202 and tank 204. Vertical fluid reclaim cycle suction line 229 connects fluid reclaim cycle suction solenoid control valve 230 to fluid reclaim cycle suction line 231 which terminates at tank 204 fluid reclaim cycle suction port 215.
Secondary suction line 227 connects suction line "T" 228 to cleaning cycle suction solenoid control valve 232 which transitions vertically to cleaning cycle suction line assembly 233a, b and c, terminating at tank 202, cleaning cycle suction port 216, which extends within tank 202 by way of suction strainer tube 257 to ultimately connect the cleaning cycle suction line to a bleed filtration system assembly 258 located in the center of circulation tank 202, comprised of a suction strainer center tube receptacle 258a, a perforated stainless steel suction strainer center tube 258b, extending vertically in the center area of a mesh suction strainer filter housing 258c containing bulk polyester fiber filter media 258d.
Pressure and flow developed by main system pump 226 is produced through two separate ports. The first, located on the top of main system pump 226, is fitted with fluid reclaim cycle pressure solenoid valve 234 which connects to fluid reclaim cycle flow valve 235. A 3/4" nipple 235a connects flow valve 235 to fluid reclaim cycle pressure line assembly 236 which is comprised of a 90° FNPT "L" 236a, a short pipe nipple in the vertical position 236b, a FNPT HB INSERT 90° "L" 236c, a preformed hose 236d, a hose insert "T" 236e, and termination hose 236f terminating in connection to first directional fluid flow discharge fitting 210, and termination hose 236g terminating in connection to second directional fluid flow discharge fitting 211.
The second and main pressure port is located on the side of main system pump 226 opposite the suction port and is fitted with cleaning cycle pressure solenoid control valve 242 which connects to cleaning cycle internal pressure line assembly 243 comprised of FNPT/Insert 90° "L" 243a first internal pressure hose 243b, fluid agitation insert "T" 243c (see next par), second internal pressure hose 243d, which connects to 90° spin down filter intake fitting 208 which, in passing through spin down filter mounting grommet 249a, both supports and pressurizes spin down filter 250 at its inlet. Straight spin-down filter discharge fitting 251 passing through spin-down filter mounting grommet 249b supports the spin-down filter at its discharge side and connects to and pressurizes exterior pressure line 21 (FIGS. 1 and 4) which passes through a grommet at the top of right side back cover 294 and out of the unit to pressurize the spray boom assembly 23.
Fluid agitation insert "T" 243-C diverts excess pressure from cleaning cycle internal pressure line assembly 243 through fluid agitation flow valve 245 (approximately 4 gpm), which connects to fluid agitation pressure line assembly 246 comprised of MNPT insert 90° "L" 246a, and fluid agitation hose 246b, terminating with attachment to fluid agitation inlet port 219 and a fan spray nozzle (not shown) in tank 204. A perforated plate (not shown) with one-sixteenth inch diameter holes may be placed mid-level and horizontaly across tank 204 to bi-sect tank 204 such that only the region above the perforated plate will be subjected to the agitation or turbulence caused by the fan spray.
The time-controlled equalization of fluid levels between common tanks 202, 203, and discharge chamber tank 204 is achieved by connecting fluid equalization line 241 to equalization port 217 on the one end and fluid equalization solenoid control valve 239 on the other, then connecting solenoid control valve 239 to timed equalization port 218, utilizing fluid equalization line 240.
Sediment is flushed automatically from spin-down filter 250 by way of spin-down filter sediment flush assembly 252 comprised of spin-down filter sediment flush fitting 252a which is a 90° FNPT/insert fitting attached to the bottom discharge port of the spin-down filter sediment bowl 250b, facilitating the connection of primary sediment flush line 252b, which connects to sediment flush solenoid control valve 252c. Sediment is then carried in flow under pressure upward through sediment flush control valve riser-subassembly 252d, comprised of a FNPT coupling 252e, a short pipe nipple 252-f, and a FNPT/insert 90° "L" fitting 252g, which connects to secondary sediment flush line 252h, which terminates in connection with spin-down filter sediment flush discharge port 220 in tank 204.
Compressed air is generated internally by air pump 265 and is injected into each of the three tanks 202, 203, 204. Air pump 265 is connected to air valve manifold 269. It then passes through air line 267a to Tank 202. Air line 267b to Tank 203 and air line 267c to Tank 204 where it is disbursed in the fluid by submerged air stones 268a, b and c (b and c not shown).
The bio-reactive fluid reclaim unit 200 is fully housed (enclosed) by outer cabinet assembly 290, comprised of electrical component control box front cover 291, electrical component control box left side cover 292, left side/front cover 263, right side back cover 294, and top cover 296. All side covers are insulated against temperature extremes with 3/4" styrofoam HDIB (high density insulation board) 298 laminated to the inside surfaces. The top cover supports 1" styrofoam HDIB 299 laminated to its inside surface which in addition to its insulation properties provides a common top seal for tanks 202, 203, and 204 by compression seal of the inner surface of the HDIB to the top rim of the tanks when fully assembled and secured in place.
Electrical component control box 205 being slightly taller than tanks 202, 203, and 204 interfaces with and projects into a corresponding groove in the top cover HDIB inner surface to provide a natural seal against water being introduced into the electrical component control box resulting from inadvertent movement of the unit or failure of certain internal pressure system components.
One inch styrofoam HDIB 299 is laminated to the under side of system base plate 201 and, in addition to its insulation properties, provides a suitable surface to be placed in contact with roofing surfaces 1, evenly distributing the full operating weight of unit 200 over the entire bottom area, eliminating the need for roof penetrations, mounting frames, etc., for most rooftop installations.
The outer cabinet assembly is attached and secured by a combination of interlocking sheet metal connections and PEM fasteners (pressed in place nuts) 300 in a manner easily understandable by those skilled in the art.
Referring to FIG. 4, fluid collector/fan mount adapter 36 includes, in its unitary section modulous, two distinct shapes, each functionally independent of the other and although joined are referred to separately herein as fluid collector 36a and fan mount riser adapter flange 36b. Fluid collector 36a receives fluid from flush nozzle 35. Flush nozzle 35 receives fluid from return pipe 32. Fluid collector flush nozzle mounting bracket 36d provides a means for rigid attachment of fluid collector flush nozzle 35 at the overall end of and in a downward angle over and directionally in line with the center flow line of fluid collector 36a. Said configuration results in the recirculating washing solution being discharged under pressure by fluid collector flush nozzle 35 during daily cleaning cycles being directed into the center flow line of fluid collector 36a where it flows in a forced counter clockwise rotation throughout fluid collector 36a, thereby emulsifying, collecting, and transporting daily oil and grease accumulations (grease inside exhaust fan 8 and mounting base 9 will seep down and collect in fluid collector 36a) to bio-reactive/fluid reclaim unit 200 by way of collector drain neck 36c, which provides the means for the attachment of fluid collector drain line 37, ultimately directing fluid from collector 36a to bio-reactive fluid reclaim unit 200.
Integral fan mount riser adapter flange 36b provides a 6" vertical extension wall 36e of the exhaust fan 8 mounting base 9. This feature facilitates the introduction of spray boom supply line 21 and fluid return line 34 through grommet or bulkhead fitting S22 installed in spray boom supply port 36f and fluid return port 36g, eliminating any need for penetrating the flue 3 or exhaust fan 8 components.
Fluid collector/fan mount adapter 36 is constructed of heavy gauge aluminum sheet, providing the rigidity to support moderate to heavy compressive loads when formed. Horizontal mounting leg 36h provides sufficient surface area to bear on the top outside rim of exhaust flue structures 3b and is intended to be permanently attached, utilizing a continuous generous bead of urethane adhesive/sealant, again eliminating penetrations in flue components. Standard sheet metal overlapping joints are utilized in the assembly of fluid collector/fan mount adapter 36; however, tolerances between components, when assembled, is considerable to allow ample free void area for a continuous bed of urethane adhesive sealant utilized both to permanently bond the components and provide a liquid fight sealed condition without soldering, welding, or utilizing penetrating fasteners.
The horizontal fan mount flange 36i, projects outward at a 90° angle from fan mount riser 36e to provide a bearing surface for the exhaust fan base 9. However, the overall projection of 36i is 1/8" less than the inside overall bearing surface of horizontal mounting leg 36h, assuring an acceptable overall finished dimension slightly smaller than that of the exhaust flue housing 2 that previously supported exhaust fan base 9. This condition provides the added clearance necessary to facilitate the re-installation of exhaust fan 8 in a hinged connection with top horizontal fan mount flange 36i. This is accomplished by utilizing one pair of strip hinges, 36-J, permanently attached to each end of horizontal fan mount flange 36i (welded) and subsequently bonded to the underside of exhaust fan base 9, utilizing a full bed of urethane adhesive/sealant over the entire surface of each hinge leaf and two 8 machine screws, nuts and washers with each hinge.
Hinging the exhaust fan allows servicing of the interior of the exhaust flue 3 and related components and the underside of the exhaust fan 10 without totally removing and handling the full weight of the exhaust fan unit 8.
Exhaust fan unit 8 is mechanically supported in the up or open position by a sliding fan support stay 36k attached to the top of the exhaust flue 3b at the one end and the underside of the exhaust fan base 9 at the other end, utilizing two stainless steel self-drilling screws at the exhaust flue 3b connection and two machine screws, nuts, and washers at the base 9 connection.
The exhaust fan 8 is secured in the down/operating position by an exhaust fan spring latch mechanism 361 attached to the underside of top horizontal fan mount flange 361 opposite the hinged side with the vertical downward flange of the exhaust fan base 9 bored to interface with 361 as exhaust fan spring latch strike hole 36m.
Low volume spray boom assembly 23, FIG. 1 and 4, is comprised of an SS braided pressure hose 23a, which connects one end to spray boom supply line 21 at bulkhead fitting 22 integral with fan mount riser 36e, and the other end to FNPT 90° "L" 23c which transitions the pressure hose to connect vertically with first boom section 23b which is the uppermost short section of pipe (galvanized steel) (length varies 6" to 18") in spray boom assembly 23. The vertical and center horizontal sections of spray boom assembly 23 are suspended within the exhaust flue 3 by spray boom top support bracket 25a, which is comprised of a stainless steel clip 25a field-formed on one end, 25b, to a 90° angle to be attached to fan mount riser 36e utilizing SS self-drilling screws, leaving sufficient horizontal length (length varies) to allow the clamp end, 25c of 25a to extend slightly over the inside edge of the top inside vertical surface of exhaust flue 3. The pipe clamp 25d encircles and secures spray boom section 23b in the vertical position.
First vertical spray boom section 23b, having a length not greater than twenty four inches (length varies) from the underside of exhaust fan unit 10 extending downward connects to galvanized "T" 23e facilitating the installation of a short galvanized nipple 23f which mounts and pressurizes rotary spray nozzle 24a. An additional three foot section of galvanized pipe for second spray boom section 23g extends downward from "T" 23e and in flues five foot or less will transition directly into the horizontal spray boom 23i with connection to horizontal spray boom "T" 23h, FIG. 1. In the case of long vertical flues, additional "T" 23e, nipples 23f, and spray nozzle 24a assemblies may be connected to extend the vertical boom sections 23b and g as required with spacing of rotary spray nozzles 24 preferrably not exceeding three feet.
First horizontal spray boom sections 23i and j, (FIG. 1), are galvanized pipe sections connected to horizontal spray boom "T" 23h extending in either or opposite directions to connect to and be supported by rotary spray nozzle 24b, (FIG. 1). Rotary spray nozzle 24b interlocks with a short stainless steel clip and spray nozzle mounting bracket (not shown buy similar to clip 25a, FIG. 4) which attaches to the inner top surface 5a of the exhaust hood 5, FIG. 1, and interlocks with an outside snap ring groove 24d in rotary spray nozzle housings 24b and 24c (24b not shown). Rotary spray nozzle 24b, having one side hole, is installed at the termination of the horizontal spray boom and serves as an end cap and boom support in addition to being a nozzle. Rotary spray nozzle 24c, having two side holes, is also utilized as a boom coupling and hanging device.
The design of the spray nozzle housing 24b and 24c when interlocked with spray nozzle mounting bracket (not shown) holds the horizontal spray boom in place both vertically and laterally. The longitudinal axis of the boom assembly is then secured by two cotter pins (not shown) installed in each end of bracket (not shown) on either side of the nozzles. Spray nozzle mounting bracket is attached to the inner surface of the exhaust hood 5, utilizing one #8 stainless steel self-drilling screw (not shown) in the center of each bracket.
Low volume rotary spray nozzles 24, appear in three configurations 24a, 24b and 24c (24c shown in FIG. 6), each having a functionally unique nozzle housing constructed of machined or molded NORYL plastic, a free machining, non-flammable synthetic compound produced by G.E. Plastics Division. Nozzle housing 24a exhibits one hole threaded FNPT in one end and no outside snap-ring groove. Nozzle Housing 24b also exhibits a FNPT threaded hole in one end and one additional side hole along with an outside snap-ring groove 24d at one end. Nozzle housing 24c exhibits three FNPT holes, one in the end and two additional holes, one in each side, and the same outside snap-ring groove 24d at one end. The outside snap-ring groove 24d is intended to interface with spray nozzle mounting bracket (not shown) and support the low volume spray boom assembly 23 (see previous section). Otherwise, all features of the three nozzles are identical. Nozzles 24 commonly exhibit a rotor (stainless steel) 24e, a rotor arm (aluminum) 24f, low volume spray emitters--2 each, 24g and 24h, an O-ring gland 24i and an O-ring 24j, an ID snap ring groove 24k and an ID snap ring 241, a self-centering, thrust-bearing 26, a bearing seat 24m, and thrust bearing chamber 24n, a fluid chamber 24O, and in the case of nozzles 24b and 24c, a MNPT plug 24p which seals the end hole subsequent to assembly and insertion of O-ring 24j in O-ring gland 24i. However, the end holes and MNPT plugs in nozzle housings 24b and 24c are optional and intended only to facilitate the ease of installation of O-ring 24j, and may be eliminated as a design feature if desired.
In assembly, rotor 24e is pressed into the center bore of self-centering, thrust-bearing 26 and bears compressive loading under pressure by rotor bearing seat flange, 24q being seated against thrust-bearing 26. Accidental disassembly of rotor 24e from thrust-bearing 26 is avoided by mating thrust-bearing detent 24r with rotor detent 26g. Rotor 24e in assembly with thrust-bearing 26 is inserted in rotor housing 24 with rotor tail shaft 24s extending into fluid chamber 24O by passing through O-ring 24j previously inserted in O-ring gland 24i. O-ring 24j seals thrust-bearing chamber 24n separate from fluid chamber 24o with minimal restriction to the friction-free rotation of rotor 24e provided by thrust-bearing 26. The rotor 24e thrust-bearing 26 assembly is held over its center rotational axis by the inherent design of self-centering, thrust-bearing 26, shown in FIG. 7. The larger diameter self-centering flange 26a of thrust bearing 26, top race 26b, is seated in nozzle housing thrust bearing seat 24m and retained against pressure by snap ring 24l inserted in snap ring groove 24k. The close tolerances of thrust-bearing seat 24m relative to thrust bearing, self-centering flange 26a horizontally and snap-ring 24l vertically assure a securely centered rotor assembly, minimizing any tendency to bind, resulting in friction-free rotation. Rotor arm 24f is attached at its center by threaded connection perpendicular to rotor stem 24v and provides the means for extending the rotor fluid canal 24t carrying fluid under pressure from fluid pressure chamber 24o through rotor arm fluid canal 24u to low volume spray emitters 24g and 24h installed in each end of rotor arm 24f by threaded connection and reactively transfers the light thrust energy produced by the volume spray emitters 24g and 24h in operation under pressure back to rotor 24e which provides the motive force that achieves reactive rotation.
The low volume rotary spray nozzles 24 are easily reconfigured to provide high or low volumes of fluid in a wide array of spray patterns by simply changing the spray emitters 24g (right angle, 180 degree, low-volume emitters such as commonly used in drip irrigation may be used) and 24h to produce the desired result. The overall size of rotary spray nozzles 24 may be altered to any desired dimension as required. Operating pressure is virtually unrestricted from less than 5 PSI up to 100 PSI and above, depending on materials used to construct the various nozzle components. As configured, low volume rotary spray nozzle 24 produces a totally diffused, non-directional spherical spray pattern, providing complete coverage in both the vertical and horizontal plane, at a very low volume of less than 0.4 gallons per minute at design operating pressure ranges between 20 and 40 PSI. It is easily understandable that a low volume of washing solution being evenly sprayed in close proximity with all interior vent hood surfaces under pressure to obtain full coverage will mildly impinge upon these surfaces and remove daily accumulations of oily residue from cooking, without copious amounts of solution flooding the interior of the vent hood 5.
Self-centering, thrust-bearing 26 is comprised of four primary components, including self-centering top race 26b and interlocking bottom race 26c, which are machined or molded of DELRIN, a free machining synthetic material exhibiting good dimensional stability and low moisture absorbency, DELRIN ball bearings 26d and glass ball bearings 26e. Top race 26b defines female interlocking detent 26f in its bore to interface with male interlocking detent 26g, on O.D. profile of bottom race 26c which, when engaged with 260f, unitizes the two races to cage and retain ball bearings 26d and 26e. Minimum but adequate clearance in the detent area minimizes frictional resistance between the races in rotation, particularly under loaded conditions. Increase in load compresses the two races slightly which increases the clearance in the detent area, transferring one hundred percent of the load, friction free, to the bearings 26d and e. Glass ball bearings 26e, which may also be stainless steel or other material, resist compression and hold their shape. However, glass will abrade itself, therefore, DELRIN ball bearings 26d are utilized alternately to isolate glass bearings 26e, further minimizing friction.
Self-centering top race 26b exhibits an outside diameter larger than the outside diameter of bottom race 26c. This extension of top race 26b is referred to as an integral top race self-centering flange 26a and serves to center thrust-bearing 26 and whatever shaft or component (rotor stem 24v shown in FIG. 6) which may be co-axial with its rotational axis or integral to its bore 26h (FIG. 7) when mounted in a comparable fixture (nozzle housing 24c shown) having an inside diameter only several thousandths larger to accommodate top race self-centering flange 26a. Thrust bearing bore 26h may be threaded or, as with top race 26b, may be detailed with an integral shaft female detent referred to here as rotor detent 26i to facilitate the installation of rotor 24e, providing an interface with a thrust-bearing detent 24r.
In as much as self-centering, thrust-bearing 26 is self-centering, a mounting fixture for shafted components, and a unitized thrust bearing, it eliminates the need for the more conventional type of assemblies where shafts are supported rotationally by ball, roller, needle bearings or bushings, longitudinally by pins, nuts, keepers, etc., and thrust bearings usually centered between thrust washers to reduce longitudinal compressive friction loads.
Universal retrofit mist-blocking baffle filter system 600, FIGS. 1, 8 and 9 are comprised of baffle filter units 601, header block 602, termination block 603, top splash guard 604, and bottom splash guard 605 all produced in various sizes to achieve universality in retrofit applications with any existing standard exhaust hoods.
Baffle filter unit 601 comprises five components in its assembly; intermediate channel sections 610 (a-d referenced), male side channel 612 (a and b shown), female side channel 614 (a and b shown), top channel stringer 616 (a and b shown) and bottom channel stringer 618 (a and b shown).
Top channel stringers 616 and bottom channel stringers 618 are identical with the exception that bottom channel stringers 618 are perforated or have openings 619 (a-c referenced) to facilitate fluid drainage during the washing cycle. Top channel stringers 616 and bottom channel stringers 618 are attached in parallel to male side channel 612 and female side channel 614 at opposite ends. They form the outer frame of baffle filter unit 601. Intermediate channel sections 610 are arranged in an evenly spaced, interlocking configuration along and perpendicular to top 616 and bottom channel stringers 618 between and parallel to male and female side channels 612 and 614. The horizontal return legs 620 (a-f referenced) common to male and female side channels 612 and 614 and intermediate channel 610 are oriented in assembly in pairs overlapping, opposed and spaced from each other to provide the means for blocking the transmission of airborne washing solution into the kitchen environment. The complete "S" track achieved by the overlapping, opposed and spaced interlocking horizontal return legs 620 adequately contains any splatter or spray resulting from or during the washing cycle within the confines of the exhaust hood 5 duct area while providing a tortuous air path for exhaust air flow with minimal static restriction. The design of male and female side channels 612 and 614 in modular sections incorporates an overlapping flange 622 with male side channel 612 which, when coupled in place parallel to female side channel 614 of the next baffle filter unit 601b, provides a flashed connection between baffle filter units 601a and b installed in series to further prevent the passage of spray or splashed washing solution beyond the baffle filter units 601.
Universal hood gutter system 700, FIGS. 1 and 9, is designed to collect the washing fluid that drains out of the exhaust hood 5 via baffle system 600 during the cleaning process. Most conventional exhaust hoods are equipped with an integral grease collection gutter which usually suffices for this purpose. However, in instances where the usual grease gutter is too shallow to handle the volume of the cleaning solution or other fault is found, universal hood gutter system 700 may be utilized in retrofit.
Universal hood gutter system 700, FIG. 9, may be of any length when assembled and is constructed of stainless steel members break-formed in three foot sections, joined by male/female overlapping connections considered standard in the sheet metal industry. These overlapping connections are intended to be joined and permanently sealed utilizing urethane adhesive sealant eliminating the need for welding, soldering, or penetrating fasteners. Horizontal flange 701 provides the means for attachment by interlocking with gutter system clip 702 which is permanently attached to the underside of exhaust hood 5 at three foot on center at each gutter lap connection. Gutter system 700 end blocks 703 close each end of the gutter system 700 and are permanently installed utilizing urethane adhesive to provide a liquid-tight connection. A large (two inch diameter) drain hole 704 is provided in one section of the gutter system 700 as a means for draining the washing fluid from the gutter system 700 into fluid return sump assembly 28.
Fluid return sump assembly 28, as seen in FIGS. 1, 5 and 9 is attached to either end or the center of the exhaust hood grease gutter 7 or universal hood gutter system 700. It is comprised of return sump mounting plate 46, sump assembly control box 48, control box cover 50, sump box 52, sump pump 54, liquid switch 56, and sump pump spacer block 58. Return sump mounting plate 46 has a two inch diameter hole 47 which mates with a corresponding hole in the exhaust hood grease gutter 7 or universal hood gutter system 700 which facilitates drainage into the fluid return sump assembly 28. Sump pump 54 is top mounted in suspension below return sump mounting plate 46. Sump pump spacer block 58 provides the means for routing the pump and liquid switch power cords 57a and 57b respectively over the top of sump pump 54 for internal connection to the power supply within control box 48.
Sump box 52 is removably top-mounted to and in suspension below return sump mounting plate 46 at the one end by engaging sump box mounting flange 52a in a corresponding sump box mounting recess 52b perpendicular and along the top of control box 48 and at the other end by sump box draw catch 52c. The bottom of sump box 52 is positioned 1/8 inches below the overall bottom of sump pump 54. As liquid from the cleaning process collects in the sump box 52, liquid switch 56 automatically senses the moisture and energizes sump pump 54 which discharges the contents by way of primary return pipe 32. Fluid return sump assembly 28 also includes an overflow drain line 59.
To compensate for solution lost during the cleaning cycle to surface retention, evaporation and fluid degradation, make-up solution comprised of clean water, fresh oxidizer, and microbes is automatically injected into the system on a daily basis via make-up line 41. This solution is maintained in make-up solution injector reservoir 40, FIGS. 1 and 9, which comprises a polypropylene reservoir tank 42 and an injector pump 44. Injector pump 44 is activated during the timed cleaning by a one-shot delay timer located in sump assembly control box 48.
The system is designed to operate as follows: Referring to FIG. 1, the bio-remediation unit 200 located on the roof systematically supports integrated naturally passive and active mechanical processes which utilizes gravity and centrifuge to reclaim washing fluid for recirculation by allowing standing unagitated grease laden solution to separate by specific gravity. More specifically, during a 23-hour, 50-minute inactive period, oil and grease hydrolyzed into highly diluted molecular suspension resultant of the cleaning process, and being of lower specific gravity than water, separates and rises to the surface of the tanks 202, 203 and 204. The underlying remediated water can then be isolated and reused.
At the beginning of the cleaning cycle, a 24-hour timer energizes a subprocess timer having six separate cam actuated contacts, the first of which energizes and opens a normally closed low voltage contactor disabling the exhaust fan 8. The second contact closes 30 seconds later energizing a pressure pump 226 within the unit which is connected to two separate sources of suction, controlled independently by solenoid valves 230, 234. The first cycle has a duration of approximately 15 seconds and is referred to as the fluid reclaim cycle. A solenoid valve 230 located in a suction line connected to the lower portion of the discharge chamber 204 opens. The fluid from the lower strata of the discharge chamber 204 is then pumped under pressure to be discharged horizontally and parallel or tangential to the sides of both the receiver 203 and circulation 202 chambers which communicate commonly. The discharge chamber 24 is connected with the receiver 203 by way of an equalization line 241. However, during the fluid reclaim cycle, the equalization line 241 is closed by a solenoid valve 239 isolating the discharge chamber 204, as the sole source of supply for said fluid reclaim cycle. Fluid flow is stratified and directed to the center or mid level of the tanks by short horizontal channel sections 208, 209 to eliminate disturbance of the heavier solids settled at the bottom of the tanks 202, 203 and likewise allows the oil and grease to remain undisturbed at the top of the tanks. In this mode, the level of the discharge chamber 204 is lowered and the levels of the receiver and circulation chambers 202, 203 rise in a circular rotation. This rotation effects centrifuge to purge lighter solids out of suspension. Additionally, wier channels 206a, 206b at the top of both the receiver 203 and circulation chambers 202 communicate commonly with the discharge chamber 204. The lip of the openings to wier channels 206a, 206b are perpendicular to the direction of the rotating fluid providing a means for controlled discharge of the lower gravity oil and grease isolated at the top of the solution once the level in the receiver and circulation tanks 202, 203 sufficiently raises the oil and grease to be force spilled over into and trapped in the discharge chamber 204 to remain isolated there during the subsequent cleaning cycle. The fluid contained in the receiver and circulating chambers 202, 203 is thereby reclaimed free of oil and grease and particulate matter ready to be recirculated through the spray boom 23 in the subsequent cleaning cycle. To complete the fluid reclaim cycle, fluid equalization solenoid control valve 239 opens to allow the fluid levels of the three tanks 202, 203, 204 to equalize and remains open during the cleaning cycle.
The oil and grease transferred to and trapped in the discharge chamber 204 resultant of the fluid reclaim cycle is re-hydrolyzed into molecular suspension with the microbe-rich emulsifier in the discharge chamber 204. This is accomplished by diverting part of the excess volume of solution generated by the pressure pump 226 during the cleaning cycle by way of a "T" 243c in the primary pressure line 243. The diverted volume is controlled by a flow valve 245 which limits a specific amount of reclaimed washing fluid to be discharged by way of a fan spray nozzle (not shown) positioned over and directed at a downward angle into the surface of the oil and grease floating in the discharge chamber 204 to agitate the fluid above the perforated plate (not shown).
When the fluid has been reclaimed, a timer located in the bioremediation unit 200 located on the roof 1 is set to activate a short, ten minute cleaning cycle during off or slow times. When the system is energized: 1. A normally closed contactor opens and disables the exhaust fan 8 to prohibit the fan from exhausting atomized cleaning solution into the atmosphere. 2. A pressure pump 226 draws suction from one of three tanks in the bioremediation unit (the circulation chamber 202) and pressurizes a low volume, low pressure spray boom assembly 23. Said assembly 23 is comprised of rotary nozzles 24 connected by pipe sections 23b, 23g, etc. (FIG. 4) and mounted vertically inside an exhaust flue 2 and horizontally along the length of any existing conventional commercial or institutional kitchen exhaust hood 5 above and behind the baffle filter bank 601. A solution of fresh water automatically mixed with a specific amount of non-toxic PH neutral surfactant/disbursant oxidizer specifically designed to promote and enhance the propagation and proliferation of microorganic life, is sprayed inside the flue and exhaust hood 2. The solution, sprayed at an extremely low pressure and volume via the special spray nozzles 24 providing complete coverage and mild impingement, is sufficient to remove the cooking oil and animal fat accumulated through a normal day's kitchen operation. The oils are in suspension or entrained in the washing fluid and drain down the baffle units 601 for collection by the gutter 700 which drains directly into the sump box 52. There, the dirty fluid is collected and returned by the sump pump 54 through the return piping system 32 installed in the hood 5 and flue 2 where it passes through the vertical section 36e of the fan/flue riser 36 and is emptied under pressure into the fluid collector 36a. There, the swirling fluid washes the grease that drains down the outer surface of the exhaust fan 8 and/or oozes out between the fan 8 and flue 2 and into fluid collector 36a.
All cleaning completed, the fluid then drains from the fluid collector 36a back into the bioremediation unit 200 (the receiver chamber 203). The receiver chamber 203 is the only tank continuously connected to the circulation chamber 202. This connection is made by a permanent pipe conduit 212 in the center portion of the chambers 202, 203. Therefore, the fluid is circulated only in the lower portion of the circulation chamber 202, which leaves any lower gravity fluid such as oil and grease virtually undisturbed, floating at the top of the tank 202, and sediment undisturbed at the bottom.
At the completion of the timed cleaning cycle the exhaust fan contactor closes, energizing the fan 8. A metered amount of fresh, non-toxic PH neutral surfactant/disbursement oxidizer solution contained in makeup solution injector reservoir 40 (FIG. 9) also containing a concentrated level of highly potent freshly cultured hydrocarbon-specific micro-organisms, is introduced by timed injection into the fluid return sump assembly 28, FIG. 5. During the 24 hr. interval when the cleaning solution is at rest in the bioreactive fluid reclaim unit 200, the oily pollutants separate by specific gravity and float to the surface of the tanks 202, 203, 204 where they are biodigested and converted to air, water and trace amounts of fatty acids. When the next cleaning cycle is activated, the pump 226 picks up the rejuvenated higher gravity cleaning fluid from the center level of the circulator tank 202 and cycles it through the exhaust hood/flue 5, 2 to drain into the sump assembly 28 where it combines with the new surfactant solution charged with fresh microbes at the first of each cleaning cycle. The circulation process thoroughly mixes the fluid and is thereby renewed daily.
In as much as the system takes on fresh makeup water and fresh surfactant/microbe solution daily, it must naturally, automatically discharge a certain amount of fluid as it equalizes at the full level and overflows. This is accomplished via a discharge pipe 214 connecting the discharge chamber 204 to the top of the nearest sewer drain vent stack 11, common to the kitchen floor drain system 12, 13 terminating in the main grease trap 14 integral with the sewer system (not shown). This process guarantees the automatic daily inoculation of the main grease trap 14 and sewer drain lines with microbe enriched emulsifier/oxidizer solution to offset any negative impact as a result of the introduction of toxic chemicals into the sewer drains by kitchen staff. This completes the cleaning and bioremediation process. By utilizing this process and the system relative thereto, one is able to eliminate the need of steam cleaning commercial kitchen exhaust hoods and related costs, avoid premature roof failure, eliminate the fire hazard associated with residual grease build-up, reduce insect and rodent infestation, reduce foul odors, and greatly reduce the volume of grease accumulating in the main grease trap, thereby reducing the need for frequent pumping (grease removal) and associated costs.
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A commercial and institutional kitchen retrofit system for 1. the automatic daily cleaning of commercial kitchen exhaust hoods and flues, 2. a low pressure, low volume, recirculating cleaning system designed for the removal of oily residue from hard surfaces and the accelerated bioremediation of the resulting collective hydrocarbon waste, 3. the collection and elimination of roof-top grease accumulations, 4. the systematic on site incubation and enhanced propagation of cultured, hydrocarbon specific, bacterial microorganisms in an automatically mixed aqueous solution containing PH neutral oxidizers and hydrocarbon base emulsifiers altogether, producing a regenerative, recyclable cleaning solution specifically developed for use in 5. and the automatic daily introduction of an oxygen enriched, microbe charged solution into kitchen drain lines, thereby reducing the stoppage of drains caused by the solidification of grease and ultimately promoting the biodigestation and reduction of accumulated grease in the main grease trap integral to the sewer system.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/644,269 entitled LOW DIFFUSIVITY BARRIER FLUID PACKING SYSTEM filed May 8, 2012.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to valves and, more particularly, to a liquid barrier packing system adapted for integration into a valve and operative to satisfy very low fugitive emission leakage standards.
2. Description of the Related Art
In a typical valve construction, a valve stem may undergo a turning or sliding movement, or a combination of both movements, within its sleeve during the process of the valve moving between its open and closed configurations. In this regard, the sealing of the stem must be adequate to contend with such movement, while at the same time ensuring maintenance of fluid tightness against the pressure of the fluid flowing through the valve. A widely used type of stem sealing is a compression packing in which a gland or sleeve is used to apply a compressive force to a compression packing which surrounds a portion of the length of the stem. The resulting radial pressure of the packing onto the stem provides the desired seal so long as the radial pressure exceeds the pressure of fluid in the valve.
In certain valve configurations, compression may be applied to the packing through the use of packing bolts which are each attached at one end to a valve bonnet of the valve, and at their other end to a spigot, a flange or other projection bearing on, integral with or attached to the gland or sleeve which bears onto the packing. In this particular arrangement, the tightening of the bolts increases the pressure on the packing, thus facilitating the application of radial pressure onto the stem. In other valve configurations, it is known to attach a spring between the nut used to tighten the bolt and a surface of the spigot or flange. Although coil springs may be used, a conventional practice is to use Belleville springs which are essentially formed as a series of dished washers. These Belleville springs provide a “live-loaded” packing which can automatically compensate for changes that may take place in the packing under operating conditions of the valve, such as high pressures and temperatures. Since the volume of the packing material may reduce under certain operating conditions, or the temperature increase of the bolts and their further elongation may result in a load loss, the spring pressure compensates for such reduction and maintains the required pressure, thus avoiding potential harmful effects to the sealing of the stem in an unsprung valve which could result from the reduction in the packing material volume. Alternatively, if the volume of the packing material increases (which can happen with certain packing materials), the radial pressure of the stem in an unsprung valve could increase too much, thus possibly causing sticking of the stem. The spring value, however, can accommodate the pressure increase by means of further compression of the springs.
Recently, there has been an increasing level of demand in many oil and gas applications for the low level emission of Volatile Organic Compounds (VOC's). In this regard, in a typical oil and gas production and processing plant, control valves are generally considered to be the largest contributors to the loss of VOC's. This has resulted in the owners of many of these facilities developing strict fugitive emission specifications to minimize VOC leakage attributable to the valve stem packing, with allowable valve stem packing leakage rates being very low. Additionally, various laws enacted in Europe and other jurisdictions currently define the maximum concentration level of pollutants that can be detected in the air in an industrial setting, and proximate valves located therein. These laws and regulations are having the effect of forcing valve manufactures to adopt new designs for valve packing and sealing systems to comply with the same.
However, the packing system included in many valve designs, including those which include a live-loaded packing as described above, is still often susceptible to varying levels leakage about the valve stem. Though some solutions have been developed which make use of a barrier fluid, these particular solutions do not provide a live loaded system to maintain the barrier fluid pressure at a level higher than that of the process pressure, thus diminishing the longevity of the packing integrity once in service conditions (see, e.g., U.S. Pat. No. 7,118,114). In one existing barrier fluid solution, grease is laterally injected into a valve bonnet. However, in this particular solution, the grease is typically lost after repeated valve cycling, with its efficacy as a fluid barrier thus only being somewhat temporary unless replenished on a frequent basis. As will be recognized, a loss of efficacy of the grease as a fluid barrier prior to replenishment may result in undesirable leakage. Further, the attempted replenishment of the grease while the valve is still pressurized can jeopardize the integrity of the valve packing, thus creating a potential hazard to operators if high pressure gas escapes the valve bonnet. In addition, the use of the aforementioned lateral injection technique gives rise to the potential for lateral grease escape during the operation of the valve, thus creating a possible leak source. Still further, the aforementioned solution, as currently known, lacks modalities for detecting when the grease level is falling to an ineffective level. Other solutions are relatively complex to manufacture, assemble and service. Further, the existing solutions typically ignore the role of a seal to shaft interface in friction and seal wear, and the resultant impact on leakage levels.
The present invention addresses the problem of packing leakage as it relates to VOC's by providing a low diffusivity barrier fluid or liquid packing system which is configured to be accommodated by a traditional valve stuffing box, and is further adapted to minimize VOC emissions, while also providing live-loading and continuous load monitoring functions. These, as well as other features and attributes of the present invention will be discussed in more detail below.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a fluid or liquid barrier packing system which is adapted to minimize VOC emissions, while also providing live-loading and continuous load monitoring functions. The components of the packing system (including the liquid barrier) are adapted to be installed in a traditional stuffing box of a valve utilizing a top entry method, and without the necessity of having to inject the liquid through any lateral side port(s) within the bonnet of the valve. In this regard, the packing system of the present invention has a simplified construction and does not rely upon the use of external components, thus eliminating many of the complexities of prior art approaches, as well as the need for any external pumps to inject the fluid or liquid into the valve at high pressures. Further, the packing system of the present invention reduces leakage levels as required by low emission leakage standards and specifications by creating a reverse osmosis effect, limiting the diffusivity of a gas through the packing elements of the system. Thus, the packing system of the present invention provides a simplified method to load and monitor a barrier in the stuffing box of the valve to slightly higher pressure than processed fluid pressure.
As indicated above, the packing system of the present invention is provided with, among other things, live-loading and a continuous load monitoring system. The packing system also makes use of a valve stem having a hard coated and super-finish stem coating, and is specifically configured to reduce wear, friction on valve seals, and to further keep the packing under continuous load to satisfy very low fugitive emission leakage standards. The hard coated and super-finish stem coating of the valve stem used in conjunction with the packing system of the present invention is instrumental in reducing wear and friction of the seals. These features minimize packing leakage and barrier fluid loss resulting in significant leakage reduction, while at the same time increasing the longevity of the packing system once in service. In one embodiment of the present invention, spring live loading is installed into the stuffing box of the valve via a top entry method, thus reducing the number of components and facilitating ease of assembly.
The present invention is best understood in reference to the following detailed description when read in conjunction with the accompanying drawings.
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 partial cross-sectional view of a valve including a fluid packing system constructed in accordance with a first embodiment the present invention;
FIG. 2 is a partial cross-sectional view of the valve shown in FIG. 1 but depicting the fluid packing system of the first embodiment in a partially assembled state;
FIG. 3 is a partial cross-sectional view of a valve including a fluid packing system constructed in accordance with a second embodiment the present invention; and
FIG. 4 is a partial cross-sectional view of the valve shown in FIG. 3 but depicting the fluid packing system of the second embodiment in a partially assembled state.
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
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, FIGS. 1 and 2 partially depict an exemplary valve 100 which includes a low fugitive emission, fluid or liquid barrier packing system 101 constructed in accordance with a first embodiment of the present invention. The exemplary valve 100 having the packing system 101 integrated therein possesses certain structural features. More particularly, the valve 100 includes a body, which itself comprises a valve bonnet 4 . Extending axially through the valve bonnet 4 is a central passageway 12 . As seen in FIGS. 1 and 2 , the passageway 12 extending through the valve bonnet 4 is not of uniform inner diameter. Rather, the passageway 12 is divided into an upper section which is of the first inner diameter, and a lower section which is of a second inner diameter exceeding that of the upper section. As a result, the upper and lower sections of the passageway 12 are separated from each other by an annular shoulder. Advanced through the passageway 12 is elongate valve stem 1 of the valve 100 , the reciprocal or rotary movement of which opens and closes the valve 100 in a conventional manner.
The valve stem 1 of the valve 100 is preferably provided with a hard coated and super-finish stem coating for reasons which will be discussed in more detail below. Additionally, as further seen in FIGS. 1 and 2 , the diameter of the valve stem 1 is less than that of the upper section of the central passageway 12 , such that an annular gap is normally defined between the valve stem 1 and that inner surface portion of the valve bonnet 4 defining the upper section of the central passageway 12 .
The packing system 101 integrated into valve 100 resides within both the upper and lower sections of the passageway 12 , with portions of the packing system 101 surrounding and exerting radial pressure against the valve stem 1 . When viewed from the perspective shown in FIG. 1 , the packing system 101 comprises an annular, upper packing 13 which circumvents the valve stem 1 and has a generally U-shaped cross-sectional configuration. The upper packing 13 is preferably fabricated from a material which is adapted to maintain a fluid tight seal against the outer surface of the valve stem 1 even upon the sliding movement of the valve stem 1 relative to the upper packing 13 . In addition to the upper packing 13 , the packing system 101 includes a lower packing 6 which is identically configured to, and may be fabricated from the same material as, the upper packing 13 . As such, the lower packing 6 also circumvents the valve stem 1 and is operative to maintain a fluid tight seal against the outer surface of the valve stem 1 despite any sliding movement of the valve stem 1 relative thereto.
As further seen in FIG. 1 , the upper and lower packings 13 , 6 each reside within the upper section of the central passageway 12 , and are disposed in spaced relation to each other such that annular channels defined by the upper and lower packings 13 , 6 as a result of the U-shaped cross-sectional configurations thereof face each other. The upper and lower packings 13 , 6 are also effectively compressed between the outer surface of the valve stem 1 and that interior surface of the valve bonnet 4 defining the upper section of the passageway 12 such that the upper and lower packings 13 , 6 are each disposed in slidable, sealed engagement with the valve bonnet 4 , in addition to being in slidable, sealed engagement with the valve stem 1 .
The packing system 101 further comprises a fluid or liquid barrier 14 which is captured between the upper and lower packings 13 , 6 . More particularly, as seen in FIG. 1 , the barrier 14 is disposed or filled into that portion of the annular gap between the valve stem 1 and valve bonnet 4 which is bounded by the upper and lower packings 13 , 6 . The migration of the barrier 14 beyond the upper and lower packings 13 , 6 is prevented by the above-described fluid tight engagement between such upper and lower packings 13 , 6 and each of the valve stem 1 and valve bonnet 4 . In an exemplary embodiment of the present invention, the barrier 14 is a viscous liquid such as grease which is formulated to provide certain fluid sealing characteristics within a prescribed range of operating temperatures for a prescribed type of process fluid flowing through the valve 100 .
The packing system 101 further comprises an annular load sensor or load cell 15 which is positioned upon and directly abuts the upper packing 13 . As such, the load cell 15 also resides within the upper section of the passageway 12 within the annular gap defined between the valve stem 1 and the valve bonnet 4 . The load cell 15 is effectively captured between the upper packing 13 and a packing follower 16 which is also included in the packing system 101 . As seen in and as viewed from the perspective shown in FIG. 1 , the packing follower 16 includes an annular upper section which is of a first outer diameter, and a tubular lower section which protrudes from the upper section and is of a second outer diameter less than that of the first outer diameter of the upper section. As a result, the upper and lower sections of the packing follower 16 are separated by an annular shoulder. The lower section is also of the length L shown in FIG. 1 . The packing follower 16 further defines a central bore which extends axially therethrough, and an ancillary passage 17 . The valve stem 1 is slidably advanced through the central bore of the packing follower 16 . Additionally, one end of the passage 17 terminates at the outer, peripheral surface of the upper section of the packing follower 16 , with the opposite end terminating at the distal end or rim of the lower section thereof. The passage 17 is used to accommodate an electrical signal transfer wire 18 which extends from the load cell 15 , through the packing follower 16 , and hence to the exterior of the valve 100 as shown in FIG. 1 . As will be recognized, the lower section of the packing follower 16 is dimensioned so that the same is capable of being slidably advanced into the upper section of the passageway 12 into the annular gap defined between the valve stem 1 and the valve bonnet 4 . It is contemplated that the lower section of the packing follower 16 will normally be advanced into the upper section of the passageway 12 to a depth whereat the shoulder defined between the upper and lower sections of the packing follower 16 will be abutted against or disposed in close proximity to the top, distal end of the valve bonnet 4 as viewed from the perspective shown in FIG. 1 (and as also shown in FIG. 3 related to the second embodiment of the present invention).
The packing system 101 further comprises an annular lower spacer 7 which directly abuts the lower packing 6 . As such, the spacer 7 also resides within the upper section of the passageway 12 within the annular gap defined between the valve stem 1 and the valve bonnet 4 . The spacer 7 is effectively captured between the lower packing 6 and a tubular loading piston 8 which is also included in the packing system 101 . As seen in and as viewed from the perspective shown in FIG. 1 , the loading piston 8 includes a tubular upper section which is of a first outer diameter, and an annular lower section which is of a second outer diameter exceeding that of the first outer diameter of the upper section. As a result, the upper and lower sections of the loading piston 8 are separated by an annular shoulder. The loading piston 8 further defines a central bore which extends axially therethrough, and slidably accommodates the valve stem 1 . Disposed in the peripheral outer surface of the lower section of the loading piston 8 is a continuous groove or channel which accommodates an annular bushing 9 . The bushing 9 is sized and configured to be disposed in continuous, sliding contact with that interior surface of the valve bonnet 4 defining the lower section of the passageway 12 . As seen in FIG. 1 , the upper section of the loading piston 8 is dimensioned so that the same is capable of being slidably advanced into the upper section of the passageway 12 into the annular gap defined between the valve stem 1 and the valve bonnet 4 . However, the size and configuration of the lower section of the loading piston 8 makes it incapable of being advanced into the upper section of the passageway 12 , the lower section of the loading piston 8 thus being confined to the lower section of the passageway 12 .
The packing system 101 further comprises an annular spring retainer 11 which circumvents the valve stem 1 and is constrained to a prescribed location within the lower section of the passageway 12 . As further seen in FIG. 1 , positioned and extending between the lower section of the loading piston 8 and the spring retainer 11 is at least one, and preferably a series of internal springs 10 . When viewed from the perspective shown in FIG. 1 , the spring(s) 10 , are operative to normally bias the loading piston upwardly toward the top, distal end of the valve bonnet 4 . In the packing system 101 , the lower spacer 7 , loading piston 8 , spring(s) 10 and spring retainer 11 collectively define a live-loading sub-assembly 111 of the packing system 101 which is operative to maintain a prescribed level of compressive pressure on the upper and lower packings 13 , 6 and the barrier 14 disposed therebetween.
Those of ordinary skill in the art will recognize that from the perspective shown in FIG. 1 , the structural features of the valve 100 to the right side of the valve stem 1 (though not being fully shown) are essentially a mirror image of those shown to the left of the valve stem 1 , the exception being that the packing follower 16 includes only the single ancillary passage 17 formed therein and extending therethrough. Additionally, in FIG. 1 , the packing follower 16 , the load cell 15 and the upper packing 13 are further shown in phantom to the right side of the valve stem 1 in non-final states of assembly prior to the advancement thereof to their preferred locations or orientations within the upper section of the central passageway 12 . As previously explained, it is contemplated that in the valve 100 including the fully assembled packing system 101 , the upper packing 13 , the load cell 15 positioned thereon, and the lower section of the packing follower 16 will each reside within the upper section of the passageway 16 in the annular gap defined between the valve stem 1 and valve bonnet 4 , with the shoulder defined between the upper and lower sections of the packing follower 16 abutting or being disposed in close proximity to the top, distal end of the valve bonnet 4 .
During the operation of the valve 100 including the packing system 101 , the combination of the upper and lower packings 13 , 6 and the barrier 14 therebetween provides an effective, fluid-tight seal which prevents fluid migrating upwardly through the lower section of the passageway 12 from further migrating through the upper section of the passageway 12 and escaping the valve 100 via the top, distal end of the valve bonnet 4 . Despite the reciprocal upward and downward or rotary movement of the valve stem 1 during the operation of the valve 100 , the upper and lower packings 13 , 6 and barrier 14 therebetween are essentially maintained in the orientation shown in FIG. 1 , though the upper and lower packings 13 , 6 are capable of some measure of slidable movement along that interior surface of the valve bonnet 4 defining the upper section of the passageway 12 . Providing the valve stem 1 with the hard coated and super-finish stem coating reduces friction and thus premature wear of the upper and lower packings 13 , 6 despite repeated cycles of the slidable movement of the valve stem 1 relative thereto.
In addition, despite increases or decreases in the volume of the barrier 14 and/or changes in the dimensional characteristics of the upper and lower packings 13 , 6 resulting from changes in the operating condition of the valve (e.g., pressures and/or temperature changes), the fluid pressure of the barrier 14 is maintained above the process pressure of the fluid flowing through the valve 100 as a result of the live-loading thereof attributable to the above-described live-loading sub-assembly 111 comprising the lower spacer 7 , loading piston 8 , spring(s) 10 and spring retainer 11 . As is apparent from FIG. 1 , this live-loading sub-assembly 111 , and in particular the loading piston 8 thereof, is capable of a range of movement roughly equal to that defined by the dimension H 1 shown in FIG. 1 . In the embodiment of FIG. 2 , the loading piston 8 is depicted at the upward limit of its range of movement toward the top, distal end of the valve bonnet 4 , such upward movement being limited by the abutment of the shoulder defined between the upper and lower sections of the loading piston 8 against the shoulder defined between the upper and lower sections of the central passageway 12 . When the loading piston 8 is at its upward movement limit, the same is separated from the spring retainer 11 by a gap which accommodates the spring 10 and is of the height L 1 shown in FIG. 2 . Further, the load cell 15 , which is captured between the upper packing 13 and packing follower 16 as described above, is operative to facilitate continuous load monitoring of the load applied to the seal collectively defined by the upper and lower packings 13 , 6 and intervening barrier 14 , thus providing an additional modality to monitor the integrity of such seal through verification of the fluid pressure of the barrier 14 exceeding the process pressure of the fluid pressure flowing through the valve 100 .
In the valve 100 , it is contemplated that the upper and lower packings 13 , 6 of the packing system 101 may be fabricated from different materials rather than from the same material, may have the same or differing geometries. Over time, due to gas diffusivity into the upper and lower packings 13 , 6 , gas may further solubilize into the barrier 14 . In the event this happens, the formation of the upper and lower packings 13 , 6 from materials which impart the same tightness capacity may cause gas to escape from the upper packing 13 and migrate out of the valve 100 , rather than escaping from the lower packing 6 which would normally result in the gas cause instead being directed back into the interior of the valve 100 . In this regard, fabricating the lower packing 6 from a material imparting slightly less tightness in comparison to the upper packing 13 may be used to facilitate a back re-diffusion of barrier solubilized gas back into the interior of the valve 100 .
FIG. 2 depicts the valve 100 , and in particular the packing system 101 thereof as shown in FIG. 1 , in a partially assembled state. More particularly, as shown in FIG. 2 , with the live-loading sub-assembly of the packing system 101 being fully assembled, the lower spacer 7 being positioned upon the upper section of the loading piston 8 , and the lower packing 6 being positioned upon the lower spacer 7 , a liquid barrier filling device 3 is used to facilitate the introduction of the barrier 14 into the packing system 101 . As seen in and as viewed from the perspective shown in FIG. 2 , the filling device 3 is similarly configured to the packing follower 16 , and includes an annular upper section which is of a first outer diameter, and a tubular lower section which protrudes from the upper section and is of a second outer diameter less than that of the first outer diameter of the upper section. As a result, the upper and lower sections of the filling device 3 are separated by an annular shoulder. The filling device 3 further defines a central bore which extends axially therethrough, and an ancillary passage 19 . The valve stem 1 is slidably advanced through the central bore of the filling device 3 . Additionally, one end of the passage 19 terminates at the outer, peripheral surface of the upper section of the filling device 3 , with the opposite end terminating at the distal end or rim of the lower section thereof. Disposed within the inner surface of the upper section of the filling device 3 which partially defines the central bore thereof is a continuous groove or channel which accommodates an O-ring 2 . Similarly, disposed within the outer surface of the tubular lower section of the filling device 3 is a continuous groove or channel which accommodates an O-ring 5 .
As further seen in FIG. 2 , the lower section of the filling device 3 is dimensioned so that the same is capable of being slidably advanced into the upper section of the passageway 12 into the annular gap defined between the valve stem 1 and the valve bonnet 4 . When the filling device 3 is used to facilitate the introduction of the barrier 14 into the packing system 101 , it is contemplated that the lower section of the filling device 3 will initially be advanced into the upper section of the passageway 12 to a depth whereat the shoulder defined between the upper and lower sections of the filling device 3 will be abutted against or disposed in close proximity to the top, distal end of the valve bonnet 4 as viewed from the perspective shown in FIG. 2 . Upon such advancement, the O-ring 2 effectively creates a seal between the filling device 3 and the valve stem 1 , with the O-ring 5 effectively creating a seal between the filling device 3 and the valve bonnet 4 . Thereafter, the passage 19 of the filling device 3 is used to channel the barrier 14 from the exterior of the valve 100 to and above the lower packing 6 .
After a prescribed amount of the barrier 14 has been introduced into the upper section of the passageway 12 , the filling device 3 is completely retracted and withdrawn from within the passageway 12 , and removed from the valve 100 . Such retraction and removal of the filling device 3 is followed by the advancement of the upper packing 13 into the upper section of the passageway 12 to assume the orientation shown in phantom in FIG. 1 . Subsequent to the load cell 15 being positioned upon the upper packing 13 while still in its position shown in phantom in FIG. 1 , the packing follower 16 is then advanced over the valve stem 1 and used to effectively push the upper packing 13 and load cell 15 downwardly into the passageway 12 to the general orientations also shown in FIG. 1 wherein the upper packing 13 also comes into contact with the barrier 14 previously filled into the passageway 12 . Those of ordinary skill in the art will recognize that the use of the filling device 3 is exemplary, and that the assembly of the packing system 101 within the valve 100 may potentially be accomplished through the use of alternative assembly techniques which do not entail the use of the filling device 3 .
Referring now to FIGS. 3 and 4 , there is partially depicted an exemplary valve 200 which includes a low fugitive emission, fluid or liquid barrier packing system 201 constructed in accordance with a second embodiment of the present invention. The exemplary valve 200 having the packing system 201 integrated therein possesses certain structural features. More particularly, the valve 200 includes a body, which itself comprises a valve bonnet 20 . Extending axially through the valve bonnet 20 is a central passageway 22 . As seen in FIGS. 3 and 4 , the passageway 22 extending through the valve bonnet 20 is not of uniform inner diameter. Rather, the passageway 22 is divided into an upper section which is of the first inner diameter, and a lower section which is of a second inner diameter which is less than that of the upper section. As a result, the upper and lower sections of the passageway 22 are separated from each other by an annular shoulder. Advanced through the passageway 22 is elongate valve stem 23 of the valve 200 , the reciprocal or rotary movement of which opens and closes the valve 200 in a conventional manner.
The valve stem 23 of the valve 200 is preferably provided with a hard coated and super-finish stem coating for reasons which will be discussed in more detail below. Additionally, as further seen in FIGS. 3 and 4 , the diameter of the valve stem 23 is less than that of the upper section of the central passageway 22 , such that an annular gap is normally defined between the valve stem 23 and that inner surface portion of the valve bonnet 20 defining the upper section of the central passageway 22 .
The packing system 201 integrated into valve 200 resides solely within the upper section of the passageway 22 , with portions of the packing system 201 surrounding and exerting radial pressure against the valve stem 23 . When viewed from the perspective shown in FIG. 3 , the packing system 201 comprises an annular, upper packing 24 which circumvents the valve stem 23 and has a generally U-shaped cross-sectional configuration. The upper packing 24 is preferably fabricated from a material which is adapted to maintain a fluid tight seal against the outer surface of the valve stem 23 even upon the sliding movement of the valve stem 23 relative to the upper packing 24 . In addition to the upper packing 24 , the packing system 201 includes a lower packing 25 which is identically configured to, and may be fabricated from the same material as, the upper packing 24 . As such, the lower packing 25 also circumvents the valve stem 23 and is operative to maintain a fluid tight seal against the outer surface of the valve stem 23 despite any sliding movement of the valve stem 23 relative thereto.
As further seen in FIG. 3 , the upper and lower packings 24 , 25 each reside within the upper section of the central passageway 22 , and are disposed in spaced relation to each other such that annular channels defined by the upper and lower packings 24 , 25 as a result of the U-shaped cross-sectional configurations thereof face each other. The upper and lower packings 24 , 25 are also effectively compressed between the outer surface of the valve stem 23 and that interior surface of the valve bonnet 20 defining the upper section of the passageway 22 such that the upper and lower packings 24 , 25 are each disposed in slidable, sealed engagement with the valve bonnet 20 , in addition to being in slidable, sealed engagement with the valve stem 23 .
The packing system 201 further comprises a fluid or liquid barrier 26 which is captured between the upper and lower packings 24 , 25 . More particularly, as seen in FIG. 3 , the barrier 26 is disposed or filled into that portion of the annular gap between the valve stem 23 and valve bonnet 20 which is bounded by the upper and lower packings 24 , 25 . The migration of the barrier 26 beyond the upper and lower packings 24 , 25 is prevented by the above-described fluid tight engagement between such upper and lower packings 24 , 25 and each of the valve stem 23 and valve bonnet 20 . In an exemplary embodiment of the present invention, the barrier 26 is a viscous liquid such as grease which is formulated to provide certain fluid sealing characteristics within a prescribed range of operating temperatures for a prescribed type of process fluid flowing through the valve 200 .
The packing system 201 further comprises an annular load sensor or load cell 27 which is positioned upon and directly abuts the upper packing 24 . As such, the load cell 27 also resides within the upper section of the passageway 22 within the annular gap defined between the valve stem 23 and the valve bonnet 20 . The load cell 27 is effectively captured between the upper packing 24 and a packing follower 28 which is also included in the packing system 201 . As seen in and as viewed from the perspective shown in FIG. 3 , the packing follower 28 includes an annular upper section which is of a first outer diameter, and a tubular lower section which protrudes from the upper section and is of a second outer diameter less than that of the first outer diameter of the upper section. As a result, the upper and lower sections of the packing follower 28 are separated by an annular shoulder. The lower section of the packing follower is also of the length L. The packing follower 28 further defines a central bore which extends axially therethrough, and an ancillary passage 29 . The valve stem 23 is slidably advanced through the central bore of the packing follower 28 . Additionally, one end of the passage 29 terminates at the outer, peripheral surface of the upper section of the packing follower 28 , with the opposite end terminating at the distal end or rim of the lower section thereof. The passage 29 is used to accommodate an electrical signal transfer wire 30 which extends from the load cell 27 , through the packing follower 28 , and hence to the exterior of the valve 200 as shown in FIG. 3 . As will be recognized, the lower section of the packing follower 28 is dimensioned so that the same is capable of being slidably advanced into the upper section of the passageway 22 into the annular gap defined between the valve stem 23 and the valve bonnet 20 . It is contemplated that the lower section of the packing follower 28 will normally be advanced into the upper section of the passageway 22 to a depth whereat the shoulder defined between the upper and lower sections of the packing follower 28 will be abutted against or disposed in close proximity to the top, distal end of the valve bonnet 20 as shown in FIG. 3 .
The packing system 201 further comprises an annular upper spacer 31 which directly abuts the lower packing 25 . As such, the upper spacer 31 also resides within the upper section of the passageway 22 within the annular gap defined between the valve stem 23 and the valve bonnet 20 . Also included in the packing system 201 is an annular lower spacer 32 which directly abuts the shoulder defined between the upper and lower sections of the passageway 22 . As such, the lower spacer 32 also resides within the upper section of the passageway 22 within the annular gap defined between the valve stem 23 and the valve bonnet 20 . As further seen in FIG. 1 , positioned and extending between the upper and lower spacers 31 , 32 is at least one, and preferably a series of internal springs 33 . When viewed from the perspective shown in FIG. 1 , the spring(s) 33 , are operative to normally bias the upper spacer 31 upwardly toward the top, distal end of the valve bonnet 20 . In the packing system 201 , the upper and lower spacers 31 , 32 and spring(s) 33 collectively define a live-loading sub-assembly 211 of the packing system 201 which is operative to maintain a prescribed level of compressive pressure on the upper and lower packings 24 , 25 and the barrier 26 disposed therebetween.
Those of ordinary skill in the art will recognize that from the perspective shown in FIG. 3 , the structural features of the valve 200 to the left side of the valve stem 23 (though not being shown) are essentially a mirror image of those shown to the right of the valve stem 23 , the exception being that the packing follower 28 includes only the single ancillary passage 29 formed therein and extending therethrough. During the operation of the valve 200 including the packing system 201 , the combination of the upper and lower packings 24 , 25 and the barrier 26 therebetween provides an effective, fluid-tight seal which prevents fluid migrating upwardly through the lower section of the passageway 22 from further migrating through the upper section of the passageway 22 and escaping the valve 200 via the top, distal end of the valve bonnet 20 . Despite the reciprocal upward and downward or rotary movement of the valve stem 23 during the operation of the valve 200 , the upper and lower packings 24 , 25 and barrier 26 therebetween are essentially maintained in the orientation shown in FIG. 3 , though the upper and lower packings 24 , 25 are capable of some measure of slidable movement along that interior surface of the valve bonnet 20 defining the upper section of the passageway 22 . Providing the valve stem 23 with the hard coated and super-finish stem coating reduces friction and thus premature wear of the upper and lower packings 24 , 25 despite repeated cycles of the slidable movement of the valve stem 23 relative thereto.
In addition, despite increases or decreases in the volume of the barrier 26 and/or changes in the dimensional characteristics of the upper and lower packings 24 , 25 resulting from changes in the operating condition of the valve (e.g., pressures and/or temperature changes), the fluid pressure of the barrier 26 is maintained above the process pressure of the fluid flowing through the valve 200 as a result of the live-loading thereof attributable to the above-described live-loading sub-assembly 211 comprising the upper and lower spacers 31 , 32 , and spring(s) 33 . As is apparent from FIGS. 3 and 4 , this live-loading sub-assembly 211 is capable of a prescribed range of movement. In FIG. 4 , the upper spacer 31 is depicted at the upward limit of its range of movement toward the top, distal end of the valve bonnet 20 . In this instance, the upper and lower spacers 31 , 32 are separated from each other by a gap which accommodates the spring(s) 33 and is of the height L 1 shown in FIG. 4 . Further, the load cell 27 , which is captured between the upper packing 24 and packing follower 28 as described above, is operative to facilitate continuous load monitoring of the load applied to the seal collectively defined by the upper and lower packings 24 , 25 and intervening barrier 26 , thus providing an additional modality to monitor the integrity of such seal through verification of the fluid pressure of the barrier 26 exceeding the process pressure of the fluid pressure flowing through the valve 200 . Additionally, in the valve 200 , it is contemplated that the upper and lower packings 24 , 25 of the packing system 201 may be fabricated from different materials to provide the same functional characteristics as described above in relation to the upper and lower packings 13 , 6 of the packing system 101 .
FIG. 4 depicts the valve 200 , and in particular the packing system 201 thereof as shown in FIG. 3 , in a partially assembled state. More particularly, as shown in FIG. 4 , with the live-loading sub-assembly of the packing system 201 being fully assembled, and the lower packing 25 being positioned upon the upper spacer 31 , a liquid barrier filling device 34 is used to facilitate the introduction of the barrier 26 into the packing system 201 . As seen in and as viewed from the perspective shown in FIG. 4 , the filling device 34 is similarly configured to the packing follower 28 , and includes an annular upper section which is of a first outer diameter, and a tubular lower section which protrudes from the upper section and is of a second outer diameter less than that of the first outer diameter of the upper section. As a result, the upper and lower sections of the filling device 34 are separated by an annular shoulder. The filling device 34 further defines a central bore which extends axially therethrough, and an ancillary passage 35 . The valve stem 23 is slidably advanced through the central bore of the filling device 34 . Additionally, one end of the passage 35 terminates at the outer, peripheral surface of the upper section of the filling device 34 , with the opposite end terminating at the distal end or rim of the lower section thereof. Disposed within the inner surface of the upper section of the filling device 34 which partially defines the central bore thereof is a continuous groove or channel which accommodates an O-ring 36 . Similarly, disposed within the outer surface of the tubular lower section of the filling device 34 is a continuous groove or channel which accommodates an O-ring 37 .
As further seen in FIG. 4 , the lower section of the filling device 34 is dimensioned so that the same is capable of being slidably advanced into the upper section of the passageway 22 into the annular gap defined between the valve stem 23 and the valve bonnet 20 . When the filling device 34 is used to facilitate the introduction of the barrier 26 into the packing system 201 , it is contemplated that the lower section of the filling device 34 will initially be advanced into the upper section of the passageway 22 to a depth whereat the shoulder defined between the upper and lower sections of the filling device 34 will be abutted against or disposed in close proximity to the top, distal end of the valve bonnet 20 as viewed from the perspective shown in FIG. 4 . Upon such advancement, the O-ring 36 effectively creates a seal between the filling device 34 and the valve stem 23 , with the O-ring 37 effectively creating a seal between the filling device 34 and the valve bonnet 20 . Thereafter, the passage 35 of the filling device 34 is used to channel the barrier 26 from the exterior of the valve 200 to and above the lower packing 25 .
After a prescribed amount of the barrier 26 has been introduced into the upper section of the passageway 22 , the filling device 34 is completely retracted and withdrawn from within the passageway 22 , and removed from the valve 200 . Such retraction and removal of the filling device 34 is followed by the advancement of the upper packing 24 into the upper section of the passageway 22 . Subsequent to the load cell 27 being positioned upon the upper packing 24 , the packing follower 28 is advanced over the valve stem 23 and used to effectively push the upper packing 24 and load cell 27 downwardly into the passageway 22 to the general orientations shown in FIG. 3 wherein the upper packing 24 also comes into contact with the barrier 26 previously filled into the passageway 22 . Typically, the live loading sub-assembly 211 is concurrently compressed in a manner wherein the gap between the upper and lower spacers 31 , 32 is reduced to the height L 2 shown in FIG. 3 from the height L 1 shown in FIG. 4 . Those of ordinary skill in the art will recognize that the use of the filling device 34 is exemplary, and that the assembly of the packing system 201 within the valve 200 may potentially be accomplished through the use of alternative assembly techniques which do not entail the use of the filling device 34 .
This disclosure provides exemplary embodiments of the present invention. The scope of the present invention is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process may be implemented by one of skill in the art in view of this disclosure. For example, it is contemplated that the packing systems 101 , 201 may each be used in conjunction with valves which have structural and functional features differing from those described above in relation to the valves 100 , 200 .
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In accordance with the present invention, there is provided a fluid or liquid barrier packing system which is adapted to minimize VOC emissions, while also providing live-loading and continuous load monitoring functions. The components of the packing system (including the liquid barrier) are adapted to be installed in a traditional stuffing box of a valve utilizing a top entry method, and without the necessity of having to inject the liquid through any side ports of the valve. The packing system reduces leakage levels as required by low emission leakage specifications by creating a reverse osmosis effect, limiting the diffusivity of a gas through the packing elements of the system. Thus, the packing system of the present invention provides a simplified method to load and monitor a barrier in the stuffing box of the valve to slightly higher pressure than processed fluid pressure.
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This is a continuation of application Ser. No. 149,978 filed May 15, 1980, now abandoned.
RELEVANT CO-PENDING APPLICATION
Reference is made to my co-pending application Ser. No. 23,607 filed Mar. 26, 1979 and entitled, "Totally Ironless Dynamoelectric Machine."
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sources of driving power for mechanical loads and, more specifically, to hybrid-drive vehicles.
2. Prior Art
With the advent of the shortage of oil and the rapidly escalating price of it, associated with the economic and international dangers with which this deplorable situation has confronted the world, new types of transportation systems have been proposed. Amongst these is advocated the widespread use of electric cars, since these can utilize any type of fuel, wind, solar, synthetic fuels, coal, water power, hydrogen and nuclear power, for example. Anything that can be used to generate electricity can provide power for electric vehicles. Unfortunately batteries now and in the forseeable future are too heavy to provide much range or performance for electric vehicles. To rectify this situation, the United States Department of Energy has proposed that hybrid vehicles (battery-powered drive train plus a heat-engine-powered drive train), be the interim solution. There are two types of such vehicles, the first being a series hybrid, of which the diesel-electric locomotive is an example. In the series hybrid, a heat engine, usually of the internal combustion type, drives the electric generator powering the electric motors coupled to the wheels. The generator is, in actuality, an electric transmission. The other type is the parallel hybrid in which there is a battery-pack-powered electric drive coupled to the wheels, and in addition there is a heat engine, usually of the internal combustion type, also coupled to the wheels. Usually both drives in a parallel hybrid are coupled to the same set of wheels, but it is possible to have one drive coupled to one set of wheels and the other coupled to another set. When the electric drive is operating in a parallel hybrid, it is desirable to disconnect the heat engine when it is not being used, to avoid high friction losses. On the other hand when the heat engine alone is operating the vehicle, it is not necessary to disconnect the electric drive motor's rotor, since the friction loss is small, and it has the advantage of acting as a flywheel.
Such exhalted scientific organizations as Jet Propulsion Laboratory and its parent, the National Aeronautics and Space Administration, have dismissed the idea of a series hybrid as being too inefficient. To quote Briggs & Stratton engineers, who have developed an effective hybrid using their small 18 horsepower engine, "the first--and simplest--method (to build a hybrid) is to add an engine-driven generator to the electric motor to recharge its batteries. This design adds nothing to the electric motor's performance, only its range, and suffers significant mechanical-electrical-mechanical conversion losses. In short, the series approach is deemed by engineers to be an inefficient one."
The same argument has been used by JPL engineers to describe the use of an electric generator to drive the electric motor as is done with the diesel-electric locomotive. Another detracting argument is that such a generator would be much too heavy for an automobile. Earnest H. Wakefield, in his book, The Consumer's Electric Car, states that a series wound electric motor is capable of being used as a transmission without gearing because of its ability to increase its torque by the square of the current increase. Thus, an electric transmission (or series hybrid) can be more efficient than a standard transmission at lower speed range by reducing the large low speed losses. To a lesser extent this argument holds true with a shunt wound motor or even a conventional permanent magnet motor. Even JPL and Briggs & Stratton agree that the electric motor can be an effective and efficient method to start an automobile, especially if it is a series wound D.C. motor. Briggs & Stratton is quoted as saying its "hybrid gasoline-electric powered car takes advantage of the complementary characteristics of its two powerplants--the low speed power of the electric motor and the high speed performance of the gasoline engine." So we have a complementary situation. A series hybrid would be very useful and efficient in low speed city driving, while a parallel hybrid engine with a 1:1 gear ratio to the differential can perform efficiently at the higher speeds.
In overcoming the initial inertia of rest of a vehicle or other load it would be desirable to add the rectified current from an engine driven alternator to that from the battery pack, applying the sum to the electrical drive motor. With conventional alternator structure there is much elemental iron in the magnetic circuit of the alternator and passing the current from the battery pack to the motor thru the alternator would be unthinkable since the iron would saturate, causing a loss of output current from the alternator. The alternator would become merely a load.
Therefore, it is an object of this invention to overcome the general disadvantages set forth hereinbefore.
It is a further object of this invention to provide an improved hybrid electrical-heat engine drive for a mechanical load.
It is an additional object of this invention to provide an electrical drive system which provides, selectively, high torque for a desired period of time.
SUMMARY OF THE INVENTION
By utilizing as an alternator one of the type invented by me and described in my copending application Ser. No. 23,607 filed Mar. 26, 1979 and entitled "Totally Ironless Dynamoelectric Machine," it is possible to put the rectified output of such alternator in series with the battery pack powering the electric drive motor so as to give a surge of mechanical power without the magnetic saturation and loss of output which would be experienced if a conventional alternator were it to be utilized similarly.
Thus, with the invention described here, the ironless alternator may, selectively, be placed in series with, in parallel with, or in lieu of the battery pack providing electrical power to the electrical motor driving the mechanical load, e.g. the wheels of a hybrid vehicle. The ironless windings in disc-armature alternators utilized in this invention are light in weight. These alternators maintain high efficiencies at all speeds. If the electrical drive motor for the vehicle is a series-wound D.C. motor its torque increases as the square of the amperage flowing to it.
Thus, greatly improved acceleration can be realized with the combination acording to this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a hybrid vehicle according to my invention;
FIGS. 2A-2C are schematic diagrams of certain switching patterns for the switching portion of the diagram of FIG. 1.
FIG. 3A is an edge view of a disc armature--field alternator construction usable in this invention; and
FIG. 3B is a side view of a portion of FIG. 3A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, heat engine 10, which may be an internal combustion engine, a solar engine, a nuclear engine, or the like is coupled through clutch 12 (which may be an automatic one-way clutch) to differential 14, which, in turn is coupled to axles 16 and 18 which carry wheels 20 and 22, respectively. Because of the features of this invention, a gear ratio of 1:1 may be maintained from engine 10 to differential 14, which assures maximum efficiency for the power train.
An auxiliary battery 24 may be provided in connection with the ignition system of engine 10.
A drive pulley 26 is provided on engine shaft 28 for power take-off to pulley 30 on shaft 32 of alternator 34. Belt 36 intercouples pulleys 26 and 30 for power transfer between engine 10 and alternator 34. Alternator 34 is of the type described in my copending application Ser. No. 23,607 filed Mar. 26, 1979 and entitled "Totally Ironless Dynamoelectric Machine." Such a machine has no elemental iron in its magnetic circuit. The alternator may be of the disc armature or drum type described in that application. The field is provided by permanent magnets, preferably of the ceramic ferrite type. One example is shown in FIGS. 3A and 3B.
In FIGS. 3A and 3B a die-cast aluminum disc 100 contains pockets 102 for receiving ceramic magnets 104. In this configuration both bi-polar and one homo-polar surface are covered by aluminum. There are no radial conductors separating magnets, one from the other.
Because of the non-magnetic nature of aluminum both coils 106 and 108 intercept lines of flux from magnets 104 and produce AC output voltage at terminals 110, 112 and 114, 116, respectively. This is only one possible configuration for alternator 34. My prior application may be seen for other configurations.
The output of alternator 34 goes through semiconductor rectifier 40 where it is changed to D-C and is applied to terminals 41, 43 of switcher 42. Switcher 42 may be a set of electromechanical relays with appropriate contacts or the proper combination of triacs or other thyristors. Both solid state and electromechanical relays and these circuits are well known and need not be described here.
The control signal for switcher 42 is applied to terminals 44, 46. Of course, manual switching may be utilized.
The switching modes which can be achieved by switcher 42 are shown in FIGS. 2A, 2B and 2C.
In FIG. 2A, rectified output from alternator 34 is connected in parallel with the output of battery pack 50 and is applied, through speed control 52 to electrical drive motor 54. Speed control 52 is a variable electrical resistor which may be mechanically coupled to foot pedal or accelerator 56. The output shaft 58 of motor 54 is coupled through differential 60 to axles 62 and 64 which drive wheels 66, 68, respectively.
In the switching mode shown in FIG. 2A, alternator 34 may be considered merely a charging means for battery 50.
If sudden acceleration is needed the switching mode of FIG. 2B may be desirable. In that mode, battery 50 and alternator 34 are in series with each other, electrically, and are connected across motor 54. If motor 54 is a series-wound motor its output torque will go up as the square of the current flowing through it. Thus, by putting battery 54 and alternator 34 (through rectifier 40) in series, the current thru motor 54 will be significantly increased and its torque increased as the square of the increased current. Impressive acceleration of the vehicle or other load will result. The changes to series feed from parallel feed can be accomplished in response to a depression of foot pedal 56 so as to close contacts 70, 72.
This is a similar phenomenon to the depression of the accelerator in a conventional car when it is desired to put the car in "passing gear." A relay circuit which will accomplish this end is shown in FIG. 4.
In FIG. 4, relay 88 includes fixed contacts 100, 102, 104 and 106, and switch arms 108 and 110. Relay 88 also includes solenoid 112 which is connected in series with switch contacts 70, 72 and auxiliary battery 24. When contacts 70, 72 are not closed the relay contacts are as shown in FIG. 4. Battery 50 and rectifier 40 (which is rectifying the output of alternator 34) are connected in parallel across output terminals 90, 92 of switcher 42. Alternator 34 (with rectifier 40) may be considered as merely charging battery 50. When contacts 70, 72 are closed, as by depressing the accelerator foot pedal, solenoid 112 is energized and switch arms 108 and 110 move into contact with contacts 104, 106, respectively. As a result, battery 50 and rectifier 40 are connected in series across output terminals 90, 92 and motor 54 receives a surge of current. Its torque output (if it is series wound) goes up as the square of such current; and the load (e.g., the vehicle) is accelerated. The relay may be solid state or electromechanical.
FIG. 2C shows the switching mode for running motor 54 solely from alternator 34, with battery 50 eliminated from the circuit. Engine 10 drives alternator 34, the rectified output from which runs motor 54, with speed control being provided by means of variable resistor 52, which may be adjusted by means of foot pedal 56.
Manual means not shown may be provided on the control panel of the vehicle to select the switching mode of FIG. 2, and, hence the source of operating current for electrical drive motor 54.
For maximum fuel economy in highway driving the circuit to electrical motor 54 is broken by a switch 80, for example, and automatic one-way clutch 12 couples heat engine 10 to differential 14 with a 1:1 gear ratio. For maximum efficiency in city driving, automatic one-way clutch 12 de-couples heat engine 10 from differential 14 and switch 80 is closed, permitting electrical drive motor 54, alone, to propel the vehicle. This clutch change can be accomplished automatically by well-known speed sensing devices, such as centrifugal devices.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention in its broader aspects, and, therefore, the aim of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of my invention.
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By utilizing, in a hybrid (electrical-heat engine) vehicle an alternator which is totally free of elemental iron in its magnetic circuit, the alternator (with appropriate rectification means) can be connected, selectively, in series, parallel or in lieu of the storage battery pack for activating the electrical motor which drives the wheels of the vehicle or any other load mechanically coupled to the electrical motor. Quick surges of power can thus be delivered to the load to achieve, for example, rapid acceleration of a vehicle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a non-provisional patent application that hereby claims priority to U.S. Provisional Patent Application No. 61/439,695, titled Positive Drive for Sliding Gate Operation, filed Feb. 4, 2011, and which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates generally to gate control devices, and more particularly, it relates to sliding gate systems and/or gate driving mechanisms for use with linear sliding types of gates (i.e. horizontal and vertical) and associated methods.
BACKGROUND
[0003] The prior art includes numerous types of actuators and linkages for swinging type gates, and numerous devices for actuating pivoting gates as well as security barriers. One type of gate utilized in security perimeter protection is the sliding gate that can be operated open or closed by longitudinal sliding motion. These types of gates have been acted upon for their motive force by several means.
[0004] The most ubiquitous means of driving a sliding gate is with the use of a chain and sprocket arrangement wherein the ends of the chain are attached to the gate ends and wrapped around a sprocket on a gate driving motor. The chain drive has the disadvantage of requiring oiling to extend its service life and the inherent mess this makes when exposed to dirt. Further, the chains are limited in length due to sag, and stretch and wear only compound this drawback.
[0005] Another means of driving a sliding gate is rack and pinion drive, which utilizes an involute gear tooth pinion on the gate driving motor and a corresponding gear rack attached to the gate. These types of drives have the inherent disadvantage of requiring precise alignment between rack and pinion so as to not bind when the distance between rack and pinion vary, or require some means to hold the rack and pinion in intimate contact, which encourages wear in an involute gear. Further, again, these drives require lubrication to maintain their life. U.S. Pat. No. 5,261,187 to Prenger describes a spring loaded rack apparatus to attempt to get around the alignment problem, but does not address the contact issue. U.S. Pat. No. 5,515,650 to Machill describes a means of assembling a plastic rack into a channel and attaching it to the gate but does not address concerns over controlling the mesh between rack and pinion.
[0006] Yet another means of driving a sliding gate includes wheels clamped together onto a flat, relatively thin longitudinal drive member, and the arrangement utilizes frictional force generated by the clamping force and the coefficient of friction between wheel surfaces and the drive member. This means is illustrated in FIG. 2 which shows the wheels clamped upon a drive member. This means of driving a sliding gate works well with the exception of when said wheel and drive member get wet or encrusted in ice, slippage may occur when driving a heavy gate.
SUMMARY
[0007] The present invention provides a gate driving assembly and related methods that overcome drawbacks experienced in the prior art and that provide other benefits. At least one embodiment provides a gate drive mechanism that requires no maintenance or lubrication, can be used on any length of gate, is unaffected by inconsistencies in alignment, and provides a positive drive so as to ensure high forces are transmitted to the gate in any weather conditions. The gate drive mechanism of the embodiment comprises a rolling tooth profile on a linear drive member and a corresponding rolling tooth profile on the drive wheel. In this manner, the concern for wear is gone due to the rolling nature of this tooth engagement, as opposed to the sliding nature of a typical involute gear tooth in a normal rack and pinion drive.
[0008] In an embodiment the gate drive mechanism can have the drive wheel mounted on a motor which is free to translate up and down while still transmitting the linear component of force needed to move the gate. The drive wheel and the linear drive member can be made of materials or a combination of materials that minimize wear and are inherently self lubricating and non-corroding.
[0009] In accordance with one aspect, the linear drive member comprises a molded plastic rolling tooth profile with means to slide this in sections into a correspondingly shaped aluminum extrusion in order to assemble the required length of drive to accommodate a given gate length. The drive wheel can be molded from a plastic such as polyurethane (PUR), thermoplastic vulcanite (TPV), or any other such tough, resilient plastic material. This material may be combined with some other material to form the hub of the drive wheel, such that a high strength hub is provided for structural purposes.
[0010] In at least one embodiment an idler wheel can be placed opposite the drive wheel on the other side of the linear drive member for the purpose of applying a consistent and predetermined normal force to the drive wheel. The idler wheel may be plain, or it may be a second toothed drive wheel.
[0011] One embodiment provides a linear gate drive assembly for use with a gate panel. The assembly can comprise a drive rail connectable to the gate panel, wherein the drive rail has a longitudinal axis and a first drive surface. A linear drive portion has a first plurality of teeth thereon with a first rolling tooth profile, wherein the linear drive portion is coupled to the first drive surface and defines a toothed second drive surface opposite the first drive surface. A support structure is adjacent to the drive rail, and the drive rail is moveable axially relative to the support structure. One or more drive motors is coupled to the support structure. A first drive wheel is attached to the one or more drive motors and is rotatable upon activation of the one or more drive motors. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail axially. A second drive wheel is attached to the one or more drive motors and engages the second drive surface. The second drive wheel has a plurality of second teeth disposed about a circumference, and the second teeth define a second rolling tooth profile that substantially corresponds to the first rolling tooth profile, wherein the second plurality of teeth mate with the first plurality of teeth. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel.
[0012] Another embodiment provides a security gate assembly. The security gate assembly can include a gate panel laterally movable between open and closed positions. A drive rail is fixed to the gate panel and is movable with the gate panel laterally between the open and closed positions. A linear drive portion can be attached to the drive rail and has a first plurality of teeth thereon that define a toothed second drive surface opposite the first drive surface. The first plurality of teeth define a first rolling tooth profile. One or more drive motors is coupled to a support structure, and a first drive wheel is rotatably attached to the one or more drive motors. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail and gate panel laterally. A second drive wheel is attached to the one or more drive motors and engages the second drive surface. The second drive wheel can have a plurality of second teeth disposed about a circumference and that define a second rolling tooth profile substantially corresponding to the first rolling tooth profile, wherein the second plurality of teeth mate with the first plurality of teeth, and wherein rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel between the open and closed positions.
[0013] Another embodiment provides a method of forming a security gate assembly. The method can include attaching a drive rail to a gate panel, wherein the drive rail has a longitudinal axis and a first drive surface. The method can include attaching a linear drive portion to the drive rail, wherein the linear drive portion has a first plurality of teeth thereon with a first rolling tooth profile. The linear drive portion defines a toothed second drive surface opposite the first drive surface. The method can include attaching first and second drive assemblies to a support structure adjacent to the drive rail, wherein the drive rail and gate panel are moveable as a unit laterally relative to the support structure. The first drive assembly can have a first drive motor and first drive wheel pivotally coupled to the support structure. The second drive assembly can have a second drive motor and second drive wheel pivotally coupled to the support structure. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail axially. The second drive wheel engages the second drive surface. The second drive wheel has a plurality of second teeth disposed about a circumference and that have a second rolling tooth profile substantially corresponding to the first rolling tooth profile. The second plurality of teeth mates with the first plurality of teeth. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a view of a sliding gate system in accordance with an embodiment of the present invention.
[0015] FIG. 2 is a view of a prior art drive system.
[0016] FIG. 3 is an isometric view of a drive system of the sliding gate system of FIG. 1 .
[0017] FIG. 4 is an enlarged side elevation view of a portion of the drive system of FIG. 3 .
[0018] FIG. 5 is a sectional view taken substantially along line 5 - 5 of FIG. 3 .
[0019] FIG. 6 is an enlarged schematic side elevation view of a rolling tooth profile drive of an embodiment.
[0020] FIG. 7 is an enlarged schematic side elevation view of a tooth profile arrangement of another embodiment.
[0021] FIG. 8 is a sectional view of an extruded gate drive rail with a linear drive member inserted in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0022] Sliding gate systems, associated drive systems, and related methods are described in detail herein in accordance with embodiments of the present disclosure. The systems and associated assemblies and/or features overcome drawbacks experienced in the prior art and provide other benefits. Certain details are set forth in the following description and in FIGS. 1-8 to provide a thorough and enabling description of various embodiments of the disclosure. Other details describing well-known structures and components often associated with gate assemblies and associated with forming such assemblies, however, are not set forth below to avoid unnecessarily obscuring the description of various embodiments of the disclosure. Many of the details, dimensions, angles, relative sizes of components, and/or other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles, sizes, and/or features without departing from the spirit and scope of the present disclosure. In addition, further embodiments of the disclosure may be practiced without several of the details described below, while still other embodiments of the disclosure may be practiced with additional details and/or features. In the Figures, identical reference numbers identify identical, or at least generally similar, elements. Moreover, one of ordinary skill in the art will appreciate that any relative positional terms such as above, below, over, under, etc. do not necessarily require a specific orientation of the footwear assemblies as described herein. Rather, these or similar terms are intended to describe the relative position of various features of the disclosure described herein.
[0023] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.
[0024] References throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment and included in at least one embodiment of the present invention. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0025] As seen in FIG. 1 , a sliding gate system 10 consists of a gate panel 1 which contains a drive rail 3 securely fastened to the gate, and a gate operating device 2 that may be attached to a concrete pad or to a secondary structure for support.
[0026] Referring to FIG. 3 , FIG. 4 and FIG. 5 , in the illustrated embodiment, a linear drive member 4 having drive teeth 13 thereon is fixed to the drive rail 3 . An upper drive wheel 6 is attached to a drive motor 9 . This combination of wheel and motor is then mounted in upper drive arm 7 . It should be noted here that this method of drive is equally effective where the motor 9 is replaced with any of a variety of geared speed reducers or other power transmission means which support a rotary application of torque to the drive wheel.
[0027] A toothed drive wheel 5 having drive teeth 15 thereon is attached to a second drive motor 9 . This combination of the toothed drive wheel 5 and lower drive motor 9 is mounted in a lower drive arm 8 . The teeth 15 of the toothed drive wheel 5 are engaged with the teeth 13 of the linear drive member 4 .
[0028] The upper drive arm 7 and the lower drive arm 8 are rotatably connected to the gate operating device 2 , such as to a support frame, in a configuration so the upper and lower drive arms 7 and 8 can rotate relative to the support frame, thereby allowing the upper and lower drive wheels 6 and 5 to translate in a roughly vertical curvilinear path. This arrangement allows for any inconsistency in the straightness and level of the horizontal drive rail 3 as the gate panel 1 ( FIG. 1 ) translates horizontally along its path. It should be noted that any number of substantially equivalent means of allowing the combination of drive wheels and motors to translate essentially vertically while still providing reaction to the horizontal force of moving the gate could be used.
[0029] The upper drive arm 7 and the lower drive arm 8 are held together with toggle clamp 17 and spring 18 . This arrangement of the toggle clamp 17 and spring 18 provide a constant and predictable force that squeezes the upper drive wheel 6 and the toothed drive wheel 5 together thus supplying a normal force N between the upper drive wheel 6 and the horizontal drive rail 3 and between the toothed drive wheel 5 and the linear drive member 4 . The toggle claim 17 and the spring 18 are coupled to the upper and lower drive arms 7 and 8 , so as to effectively tie the upper drive wheel 6 to the lower toothed drive wheel 5 . Accordingly, the drive wheels 6 and 5 will translate in unison in the event of vertical motion of the wheels relative to the support frame. This means that the drive wheels 6 and 5 will always remain in firm engagement with the drive rail 3 and linear drive member 4 , respectively, while the toggle clamp is in the engaged position.
[0030] Referring to FIG. 6 is a close up view of the engagement of a section of the linear drive member 4 engaged with the portion of a toothed drive wheel 5 . On the linear drive member 4 , the root of the tooth 13 is formed as a substantially circular shape. The crest of the tooth 15 on the toothed drive wheel 5 is formed as a substantially corresponding circular shape, and engaged such that the crest of the tooth 15 may roll freely on the root of the tooth 13 of the linear drive member 4 . In a linear fashion, at a distance of half the pitch p along the linear drive member 4 , a crest of the tooth 14 is formed in a substantially circular shape. While the example described above refers to a substantially circular shape, other arcuate shapes, such as truly circular, ellipsoid, or any generally curvilinear shape, could be used as long as it facilitates rolling between the crest of the teeth on the drive wheel and the root of the teeth of the linear drive member.
[0031] A pressure angle θ is defined by the angle of the tangent point where the curvilinear portion of the tooth meets the curvilinear portion of the root. Hence there is a portion of torque which is transferred along the direction of the linear drive member and a portion which is imparted normal to the direction of the linear drive member. The horizontal portion is given by Fh=F Sin θ and the normal portion is given by Fn=F Cos θ.
[0032] In addition to the motive force provided by the pressure angle of the tooth, significant force is imparted from the upper drive wheel 6 to the horizontal drive rail 3 through pure friction. In this case, the frictional force is given by F=μN, where μ is the coefficient of friction between the material of the upper drive wheel 6 and the horizontal drive rail 3 .
[0033] A likewise effect is had from the frictional interface between the toothed drive wheel 5 and the linear drive member 4 . For this reason it is desirable to make the mating surface of both the upper drive wheel and the toothed drive wheel from a material that exhibits high friction versus the materials they bear against.
[0034] In operation, the toothed drive wheel 5 rolls on a tooth 15 of the wheel, then transfers to rolling on a tooth 13 of the linear drive member 4 , then back to rolling on the wheel 5 , etc.
[0035] As shown in FIG. 6 , the distance dl from the center of the toothed drive wheel, c to the crest of the tooth 15 is larger than the distance d 2 from the center to the root of the next tooth 16 . This difference in distance causes a variation in the speed that the linear drive member 4 travels given a fixed rotational speed of the toothed drive wheel 5 . Thus the average speed is based on the average radius from the center of the toothed drive wheel c. One way of minimizing this variation is to utilize a lower pressure angle. This approach is shown in FIG. 7 , where the pressure angle θ is relatively small. This leads to a relatively smaller difference between d 1 and d 2 although as noted above, the horizontal component of drive is smaller and the normal component of drive is larger, which may be undesirable.
[0036] The material for the toothed drive wheel 5 as well as the upper drive wheel 6 of an embodiment can have high coefficients of friction, low wear, wide temperature range, compliance to debris, and require no lubrication. These properties are available in a range of polymer compounds, for example polymers that are commonly injection molded such as acrylinitrile butadiene styrene (ABS), polycarbonate (PC), polyester (PES), polyethylene (PE), polystyrene (PS), acetal, polyamides (PA), polypropylene (PP), Polyvinyl chloride (PVC). These properties could also be achieved using molded rubbers, polyurethane (PU), thermoplastic vulcanate (TPV), or thermoplastic urethane (TPU). Other embodiments could use other suitable materials.
[0037] The material for the linear drive member 4 likewise can include the properties of high coefficient of friction, low wear, wide temperature range, compliance to debris, and require no lubrication. These properties are available in a range of polymer compounds, for example polymers that are commonly injection molded such as acrylinitrile butadiene styrene (ABS), polycarbonate (PC), polyester (PES), polyethylene (PE), polystyrene (PS), acetal, polyamides (PA), polypropylene (PP), Polyvinyl chloride (PVC). These properties could also be achieved using molded rubbers, polyurethane (PU), thermoplastic vulcanate (TPV), or thermoplastic urethane (TPU). Other embodiments could use other suitable materials.
[0038] Another embodiment utilizes instead of a motor driving the upper drive roller, one or more unpowered idler rollers on the opposite side of the linear drive member 4 supported by bearing means with the sole purpose to apply a normal clamping force to the toothed drive wheel 5 . In yet another embodiment, the gate drive assembly 10 uses a toothed drive wheel with the rolling tooth profile as described above that engages the teeth on the linear drive, with out using the other drive motor and drive wheel. In this alternate embodiment, the linear drive portion can be attached directly to a rigid portion of the gate panel. The toothed drive wheel can be attached to motor assembly carried by a drive arm spring loaded against the toothed drive surface. Alternatively, the toothed drive wheel can be held rigidly in a relationship to the portion of the gate with the toothed drive surface.
[0039] In another aspect of the invention, as shown in FIG. 8 , the linear drive member 4 and the drive rail 3 can be equipped with an interlocking feature 17 (of which this is just one example of) whose purpose is to hold the linear drive member from moving in all but the drive direction.
[0040] A particular embodiment of the gate assembly comprises a sliding gate, a gate operating device containing a motor, and a gate drive mechanism. The gate drive mechanism of this embodiment comprises a linear drive member with a rolling tooth profile and a drive wheel attached to the output shaft of the motor. Additionally, the drive wheel includes a rolling tooth profile that corresponds to the tooth profile on the linear drive member to which it is rotatably in contact with.
[0041] In one embodiment the motor may be constrained in the longitudinal direction and not in the vertical direction. Additionally, the motor may be mounted on an arm rotatably attached to the gate operating device.
[0042] A second motor and drive wheel may be included to drive the opposite side of the longitudinal drive member. This drive wheel may include a rolling tooth profile corresponding to a rolling tooth profile on the linear drive member with which it is rotatably in contact. Alternatively, the drive wheel on the second motor may be a conventional round drive wheel. Furthermore, one or more unpowered idler rollers may be included on the opposite side of the linear drive member.
[0043] The linear drive member or the drive wheel, or both, may be constructed from a polymeric material, such as polyurethane. Additionally, the linear drive member may be of a certain length such that when placed end to end, the pitch of the rolling tooth profile is maintained. Finally, linear drive members may be of such length that when inserted into a correspondingly shaped gate drive rail extrusion, the lengths are restrained from movement in any but the longitudinal direction.
[0044] Those skilled in the art will recognize that this drive method can apply to other barriers requiring linear motion to open and close them, and the orientation is not important.
[0045] From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Additionally, aspects of the invention described in the context of particular embodiments or examples may be combined or eliminated in other embodiments. Although advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages. Additionally not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention.
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A linear gate drive assembly with a drive rail connectable to a gate panel. A linear drive portion having a toothed drive surface is coupled to a first drive surface of the drive rail and has teeth thereon with a first rolling tooth profile. A drive wheel is attached to one drive motor and engages the first drive surface to impart an axial drive force on the drive rail. Another drive wheel is attached to another drive motor and engages the second drive surface. The second drive wheel has teeth that mate with the first teeth and that define another rolling tooth profile corresponding to the first rolling tooth profile. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface for moving the drive rail and the gate panel.
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BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for mounting and removing a hub from a shaft. More specifically the invention concerns utilization of a cylinder and a piston provided in an arrangement that may be used in one orientation to force a hub on the shaft and in a separate orientation to remove the hub from the shaft.
In the rotary machine art it is common practice to move a hub of a coupling, impeller or the like onto a shaft over which the hub has been preliminarily applied or to displace a hub from such a mounted position. Numerous types of apparatus have been used to accomplish this function.
Typical of the prior art over which this idea is an improvement is U.S. Pat. No. 3,772,759. This prior art patent discloses a device wherein hydraulic fluid is supplied to expand a chamber to force a hub onto a shaft. Some means for securing the device relative to the shaft such that the expansion force may be used to force the hub onto the shaft is provided. However to use the same apparatus to remove the hub from the shaft requires additional structure for securing the expansion apparatus to the hub. As can be seen in this patent the additional structure includes longitudinally extending rods which are secured internally within the hub. These rods are connected to a separate structure against which the expansion portion must be mounted.
The herein device utilizes a cylinder and a piston which may be mounted in a first position with the cylinder secured to the shaft such that upon the application of pressurized fluid the piston is displaced forcing the hub on the shaft similar to the prior art. However to effect removal of the hub from the shaft the assembly is simply reversed and placed in the opposite direction with the cylinder abutting the shaft and with the piston threadably engaged on its exterior surface to an interior surface of the coupling. Pressurized fluid may then be supplied to the cavity to effect displacement of the hub to remove it from the shaft.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for moving the hub of a coupling, wheel, propeller, impeller or the like into and out of a force fit position on a shaft.
It is a further object of the present invention to provide a simple two element apparatus which may be positioned in a first position to effect assembly of a hub to a shaft and a second position to effect removal of the hub from the shaft.
It is another object of the present invention to provide apparatus which may be used at the factory for assembly or in the field for maintenance purposes for easily assembling and disassembling a hub from a shaft.
It is a yet further object of the present invention to provide a combination cylinder and piston for effecting removal and assembly of a hub to a shaft without requiring additional components and without requiring that the hub be drilled and internally tapped to allow removal thereof.
It is a still further object of the present invention to provide a fast, relatively inexpensive and easy to use apparatus and method for effecting assembly and disassembly of a hub from a shaft.
Other objects will be apparent from the description to follow and the appended claims.
The above objects are achieved according to a preferred embodiment of the invention by the provision of an assembly for mounting and removing a hub from a shaft. The assembly serially includes, a tapered portion, a radially extending abutment face and a threaded end portion. A hub including a tapered portion which is complementary to the shaft tapered portion, a radially extending abutment face and an axially extending threaded portion is further included. An annular cylinder having a threaded portion for engaging the threaded end portion of the shaft when positioned for mounting the hub to the shaft, a contact face positioned to engage the shaft abutment face when the cylinder is positioned for removing the hub from the shaft, a first cylinder sliding surface and a second cylinder sliding surface is also disclosed. An annular piston having a first piston sliding surface and a second piston sliding surface each mating with the respective cylinder sliding surfaces to define a cavity therebetween, a piston threaded portion for engaging the coupling threaded portion when the piston is in position for removing the hub from the shaft, a cylinder contact face for engaging the coupling abutment face when the cylinder is in position for mounting the hub on the shaft, and said piston defines a conduit for supplying pressurized fluid to the cavity whereby when a pressurized fluid is supplied to the cavity and when the cylinder and the piston are in position for mounting the hub to the shaft cylinder, the cylinder is threadably secured to the shaft threaded end and the piston engages the hub forcing the hub on the shaft and if in position for removing the hub from the shaft, the cylinder contact face abuts the shaft abutment face and the cylinder is threadably engaged to the coupling such that by supplying pressurized fluid to the cavity, the hub is removed from the shaft.
An assembly for mounting and removing a hub from the shaft is further disclosed including cylinder means for engaging the shaft, and piston means for engaging the hub, said cylinder means and piston means together define a cavity for the receipt of pressurized fluid for forcing the cylinder means and the piston means in opposite directions to effect mounting or removing of the hub from the shaft by appropriate positioning of the cylinder means and the piston means.
DESCRIPTION OF THE DRAWING
The FIGURE is a sectional split view of the assembly shown in the top half with the components positioned to mount the hub to the shaft and in the bottom half with the components positioned to remove the hub from the shaft.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention herein will be described with reference to a cylinder and a piston for mounting a tapered hub to a tapered shaft. It is to be understood, of course, that this apparatus could be used to mount a hub to a shaft of different configuration. It is additionally to be understood that his hub could be the hub of a coupling, a hub of an impeller or any similar structure which needs to be forced onto or off a shaft. Furthermore the hub and shaft could be keyed although not necessary and not shown.
As shown in the FIGURE the top half of the diagram shows the apparatus in position for assembling the hub to the shaft. The bottom half of the drawing shows the apparatus in position for removing the hub from the shaft. All the apparatus is annular in configuration and the sectional view shown in representative of the entire configuration.
Referring to the FIGURE it may be seen that the shaft 10 includes a shaft tapered portion 12, shaft abutment face 14 extending radially outward from the shaft axis and threaded end 16 including threads 18. Coupling hub 20 includes coupling tapered portion 22 which is complementary with the shaft tapered portion 12 such that they may be positioned in a force fit relationship. Coupling hub 20 further includes coupling extension 24 which would be that portion of the coupling which may be secured to an adjacent coupling, coupling abutment face 26 and coupling threaded portion 27 extending in an axial direction including coupling threads 28.
Piston 30 is an annular element having a generally L-shaped cross section and includes piston threads 32 formed on the exterior surface of the piston and extending radially outwardly. Piston 30 further includes a first piston sliding surface 34, a second piston sliding surface 38, piston contact face 36 and piston pressure face 39. Cylinder 40 is annular in configuration and also generally L-shaped in cross section. Cylinder 40 includes cylinder threads 42 extending inwardly through a bore extending the length of the cylinder. Cylinder 40 additionally includes cylinder contact face 44 shown abutting shaft abutment face 14, in the bottom half of the FIGURE. The cylinder also includes first cylinder sliding surface 46, second cylinder sliding surface 48 and pressure face 49. O rings 80 and 82 are shown mounted between the first cylinder sliding surface and the first piston sliding surface and the second piston sliding surface and the second cylinder surface to effect a seal therebetween. Assembly cavity 50 is shown at the top half of the drawing as a cavity defined between the sliding surfaces and the pressure faces of the piston and cylinder respectively. Disassembly cavity 60 is the same cavity shown in the bottom half of the drawing. Additionally as shown only in the bottom half of the drawing is tapped hole 62 extending into the piston and communicating with conduit 64. Conduit 66 may be threadably engaged to the tapped hole 62 for effectively supplying pressurized fluid to the cavity for effecting relative displacement between the cylinder and the piston to either mount or remove a hub from a shaft. Oil supply 70 is shown generically as a means for supplying pressurized fluid to the cavity. Valve 72 is shown for use in draining oil from the cavity.
METHOD OF OPERATION
To effect assembly of the hub to the shaft, the cylinder is mounted with cylinder threads 42 engaging threads 18 of the threaded end of the shaft. The piston 30 is positioned with the piston contact face engaging the coupling abutment face of the coupling. The coupling has, of course, been prepositioned on the shaft. Pressurized fluid is then supplied to the cavity 50 such that the fluid acts on piston pressure face 39, and cylinder pressure face 49 of cavity 50 to effect relative displacement between the two. Since the cylinder is secured to the shaft the piston is displaced as shown in the top half of the FIGURE from right to left forcing the coupling hub onto the shaft.
In order to effect removal of the coupling hub from the shaft the cylinder is threadably disengaged from the threaded end of the shaft. The cylinder is then physically flipped or rotated end-to-end and the opposite end of the cylinder is placed over the threaded end portion of the shaft but not in engagement therewith such that cylinder contact face 44 abuts shaft abutment face 14. Simultaneously, with the cylinder, the piston is rotated and is now also positioned in the opposite direction with the appropriate piston sliding surfaces engaging sliding surfaces of the cylinder. The piston is then threadably engaged to the coupling with piston external threads 32 engaging coupling threads 28 to secure the coupling to the piston. Pressurized fluid is then supplied to cavity 60 forcing the cylinder to the left and the piston to the right. However, since the cylinder abut against the shaft it cannot move to the left, therefore, the piston is displaced to the right. Since the piston is threadably engaged to the coupling the coupling is moved to the right removing the coupling hub from the shaft.
In the manner above described the apparatus as provided is utilized to effectively force the hub onto the shaft and to remove the hub from the shaft depending upon the manner of application of the apparatus. No special pressure plates, extending rods tapped into the hub or other apparatus is required to effect removal of the hub.
The invention has been described with reference to a particular embodiment. It is to be understood by those skilled in the art that variations and modifications can be effected within the spirit and scope of the invention.
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Apparatus for effecting the mounting and removal of a hub from a shaft is disclosed. The combination of a piston and cylinder is designed relative to the hub to be mounted to the shaft such that by securing them in one position the hub may be forced onto the shaft utilizing pressurized fluid and by securing the piston and the cylinder in another position the hub may be forced from the shaft using a pressurized fluid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a flash device operatively associated with a camera.
2. Description of the Prior Art
A flash device of the type in which a starting signal for a DC/DC converter is produced only for a moment in response to manual operation, whereby the DC/DC converter starts operating and charges a main capacitor and when the charging current thereof decreases to a predetermined value, the operation of the DC/DC converter is substantially stopped, is known from Japanese Patent Publication No. 842/1964. However, in order that the flash device of such type may actually be used without inconvenience, there are some problems left to be solved.
In the flash device of such type, there is a disadvantage that when the power supply battery is consumed and the voltage thereof drops, the operation of the DC/DC converter is stopped even if the main capacitor is charged only to a value lower than the charging completion voltage thereof. This is because the charging current of the main capacitor also decreases with a reduction in the power source voltage.
Also, where this flash device is contained in a camera and is designed such that the DC/DC converter is energized and operated only for a moment in response to an operation of preparation for flashlight photography, for example, the operation of retracting a cover member disposed in the front of the lens out of the phototaking light path or the projecting (pop-up) operation of a light emitting portion contained in the camera, whereby the main capacitor is charged, the charging of the main capacitor will not be effected unless these operations are repeated during each cycle of flashlight photography.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide improvements in the flash device of the above-described type.
According to the present invention, there is provided a flash device in which the DC/DC converter can be forcibly operated until the main capacitor completes charging.
Also, according to the present invention, there is provided a flash device in which the operation for starting the DC/DC converter is simplified with a result that the quick photographing characteristic of flashlight photography is improved.
The invention will become more fully apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing an embodiment of the device according to the present invention.
FIG. 2 is a schematic view of a camera containing therein the flash device of FIG. 1.
FIG. 3 is a circuit diagram showing another embodiment of the device according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a main switch 2 connected to a power supply battery 1 may be closed in response to the operation of a phototaking lens cover member uncovering the lens prior to photography. A transistor 3, a booster transformer 4, a capacitor 5, a rectifying diode 6 and a resistor 7 together constitute a DC/DC converter. A main starting switch 8 is a switch for initiating the oscillation of the DC/DC converter and may be momentarily closed during the operation for the preparation for flashlight photography and, in the present embodiment, it is designed to be closed in response to the uncovering operation of the cover member. The secondary winding of the booster transformer 4 is connected to the base (control electrode) of the transistor 3. The secondary output of the booster transformer 4 charges a main capacitor 9 through the diode 6.
An auxiliary starting transistor 10 is parallel-connected to the starting switch 8. The base of the transistor 10 is connected to the power supply battery 1 through a resistor 11, and a normally closed switch 12 controls the ON/OFF of the transistor 10. The switch 12 may be opened in response to the operation for the preparation for the next one frame photography after completion of one frame photography.
A transistor 13 is further parallel-connected to the switch 8. The base of the transistor 13 is connected to the power supply battery 1 through a switch 14 and a resistor 15. The switch 14 may be closed in response to the projection (pop-up) of a flashlight emitting portion from the camera body. A transistor 16 serves to control the ON/OFF of the transistor 13. When a change-over switch 17 selects a terminal 17a, the transistor 16 is normally turned on with the power source voltage divided by a resistor 19 being applied to the base thereof through a resistor 18, and when the change-over switch 17 selects a terminal 17b, the transistor 16 is turned on with a voltage produced in the resistor 19 by the turn-on current of a neon display tube 35 adapted to be turned on upon completion of the charging of the main capacitor 9 being applied to the base thereof through the resistor 18. This change-over switch 17 selects the terminal 17a when the flashlight emitting portion is contained in the camera body, and selects the terminal 17b in response, for example, to the projecting operation when the flashlight emitting portion is projected from the camera body.
If the neon display tube 35 is turned off when the change-over switch 17 selects the terminal 17b, a transistor 21 is turned off with the bias voltage by resistors 19, 20 cut off and produces a high level release lock signal at a terminal 22. When the neon display tube 35 is turned on or when the change-over switch 17 selects the terminal 17a, the transistor 21 is turned on and produces a low level release lock releasing signal at the terminal 22.
A transistor 23, resistors 24-27, a noise absorbing capacitor 28 and a synchro switch 29 operable in synchronism with the shutter release operation of the camera together constitute an auxiliary trigger circuit for a thyristor 30. A charge charged into a trigger capacitor 31 through a resistor 32 and a trigger transformer 33 may be discharged upon turn-on of the thyristor 30 to cause a flashlight discharge tube 36 to emit light.
Referring now to FIG. 2, a cover member 100 is vertically slidable along the front face of a lens 101, and two conductors 102 and 103 are secured to the back side thereof which faces the camera body. When the cover member 100 is downwardly depressed prior to photography, the conductor 102 first connects terminals 104 and 105 to close the main switch 2. The conductor 102 is provided so that the switch 2 maintains its ON position even if the cover member 100 is moved to its lowermost position indicated by dots-and-dash line in which the cover member has been completely retracted from the front of the lens 101. The conductor 103 connects terminals 106 and 107 in the course of depression of the cover member 100 to momentarily close the switch 8.
A flashlight emitting portion 108 is vertically slidable relative to the camera body 109 along pins 110 and 111 fitted in grooves provided in the camera body. In the contained position of the flashlight emitting portion 108 shown in FIG. 2, the switch 14 is open and the change-over switch 17 selects the terminal 17a. When the flashlight emitting portion 108 is caused to project upwardly as indicated by dots-and-dash line, the change-over switch 17 selects the terminal 17b with the aid of the pin 110 and the switch 14 is closed by the pin 111.
A release lever 112 upwardly biased by a spring 113 is depressed against the force of the spring 113 by depression of a release button 114 and actuates a release plate 115. Shutter release is effected by the actuation of the release plate 115. A counter-clockwisely biased release lock member 116 is rotated clockwisely by energization of an electromagnet Mg and becomes be coupled to a projection 112a to restrain the release lever 112. By this, shutter release is hampered. The electromagent Mg is energized when the terminal 22 of FIG. 1 assumes a high level.
In the course of the operation of retracting the cover member 100 from the front of the lens, the switch 8 is momentarily closed to permit a current to flow to the resistor 7 to bias the base of the oscillating transistor 3. Thus, the oscillation by the oscillating transistor 3, the oscillating capacitor 5 and the booster transformer 4 is started. The secondary side voltage boosted by this oscillation charges the main capacitor 9 through the rectifying diode 6. This charging current is fed back to the primary side of the booster transformer 4 as the base current of the oscillating transistor 3, so that the oscillation persists even after the switch 8 has been opened. As the charging of the main capacitor 9 progresses and the charging current decreases, the base current of the oscillating transistor 3 decreases and therefore, the oscillating transistor 3 stops operating.
According to this construction and operation, charging is always started by the photography preparing operation of the camera, namely, the uncovering operation of the lens cover member and therefore, when the camera is changed over from photography not using the flash device to the condition using the flash device, the charging wait time is shortened to thereby provide a quick photographing characteristic. Also, the oscillation stops automatically and this greatly reduces the consumption of the battery caused by the photographer forgetting to open the main switch.
In the above-described construction, once the oscillation stops, it is not restarted except by closing the switch 8 again. Therefore, once flashlight is emitted for flashlight photography, reoscillation would not be started. This problem can be solved by the transistor 10 and the switch 12. That is, the normally closed switch 12 is opened in response to the operation of a shutter release mechanism or a film advance mechanism after flashlight photography has been terminated. The transistor 10 which remains in cut-off condition due to the closing of the switch 12 is biased and conducts by the power source 1 through the resistor 11 when the switch 12 is opened in response to the release of a shutter release button or to the operation at the initial stage of film advance, and starts the oscillation for boosting on behalf of the switch 8.
Also, according to the shown embodiment, even if the flashlight emitting portion 108 is contained and the switch 14 is open, the oscillation for boosting is restarted by shutter release operation of film advance operation, but if the biasing of the transistor 10, namely, the power supply to the resistor 11, is effected through the switch 14 adapted to be closed in response to the pop-up of the flashlight emitting portion, reoscillation of the DC/DC converter will occur only during the condition using the flash device.
In the above-described DC/DC converter whose oscillation is automatically stopped with a decrease in the charging current of the main capacitor 9, there is a possibility that as the power supply battery is consumed with a result that the power source voltage is reduced, the charging voltage which causes the oscillation of the main capacitor 9 to be stopped is reduced and at last, the boosting is stopped before the light emission capable voltage of the flashlight discharge tube 36 is reached. It is therefore necessary to forcibly cause the oscillation to persist until the light emission capable voltage is reached, and thereafter automatically stop the oscillation. The embodiment of FIG. 1 is designed such that such forcible oscillation is effected only during the pop-up of the flashlight emitting portion 108, namely, during the condition using the flash device, but of course, design may also be made such that the forcible oscillation is effected irrespective of the pop-up of the flashlight emitting portion 108.
The transistor 13 is used as the circuit accomplishing such forcible oscillation. When the flashlight emitting portion 108 is in its contained condition, the change-over switch 17 selects the terminal 17a. At this time, the resistor 19 is connected to the power supply battery 1, so that the transistor 16 is turned on with a result that the transistor 13 is turned off. Accordingly, when the flashlight emitting portion 108 is in its contained condition, the DC/DC converter is not forcibly oscillated.
Next, when the flashlight emitting portion 108 is projected, the change-over switch 17 selects the terminal 17b. By this, a charging completion indicating circuit including the resistor 34 and the neon display tube 35 is closed. Also, when the switch 14 is closed by the flashlight emitting portion 108 being projected, the base of the transistor 13 is connected to the power supply battery 1 through the resistor 15. When the charging of the main capacitor 9 has not yet been completed, the neon display tube 35 is not turned on and so, no current flows to the resistor 19. Accordingly, the transistor 16 is turned off with a result that the transistor 13 is turned on. The turn-on of the transistor 13, on behalf of the switch 8, causes the oscillation of the DC/DC converter to start.
When the charging of the main capacitor 9 is completed, the neon display tube 35 is turned on and the turn-on current thereof causes a voltage drop of the resistor 19 which is applied through the resistor 18 to the base of the transistor 16, which is thus turned on. Accordingly, the transistor 13 which has been ON until the neon display tube 35 is turned on is turned off and the DC/DC converter operates in a manner similar to that when the switch 8 has been opened. In this case, if the voltage of the power supply battery 1 is sufficient, the oscillation will persist for a predetermined time even if the neon display tube 35 is turned on and the transistor 13 turned off, whereafter the oscillation will be automatically stopped by a decrease in the feedback current to the transistor 3. Also, when the voltage of the power supply battery 1 has dropped, the oscillation is stopped at the same time that the transistor 13 is turned off or the neon display tube 35 is turned on.
A camera containing a flash device therein must be provided with a mechanism for locking shutter release during the oscillation of the DC/DC converter. The device according to the embodiment shown in FIG. 1 has a means for releasing the release lock by turn-on of the neon display tube 35, which means comprises the change-over switch 17, resistors 19, 20, transistor 21 and signal terminal 22. When the change-over switch 17 selects the terminal 17b, if the display tube 35 is turned on, the transistor 21 is turned on by a voltage produced in the resistor 19, through the resistor 20, and the signal terminal 22 assumes a low level and therefore, the magnet Mg of FIG. 2 is not energized and the releasing of the release lock can take place. Before the display tube 35 is turned on, the transistor 21 is turned off and the terminal 22 assumes a high level, so that the magnet Mg is energized to effect release lock. Also, when the flashlight emitting portion 108 is in its contained condition, the change-over switch 17 is connected to the terminal 17a. Since the voltage from the power source 1 is directly applied to the terminal 17a, the transistor 21 is always in its ON state, that is, the terminal 22 assumes a low level and the release lock is released.
The resistor 32, thyristor 30, trigger coil 33 and capacitor 31 together constitute a main trigger circuit for the flashlight discharge tube 36. By turn-on of the thyristor 30, the secondary side output of the trigger coil 33 is applied to the discharge tube 36 to cause light emission. An auxiliary trigger circuit for triggering the thyristor 30 is supplied with power from the primary side of the booster transformer through the switch 14. Therefore, the auxiliary trigger circuit operates only during pop-up of the flashlight emitting portion 108. When the synchro switch 29 is closed in synchronism with the opening of an aperture for exposure by the shutter, the transistor 23 is turned on through the resistor 25 and the divisional voltage of the resistors 26, 27 is applied to the gate of the thyristor 30, which is thus turned on to cause the flashlight discharge tube 36 to emit light. Resistor 24 is a leak cut resistor.
In the flash device wherein the oscillation of the DC/DC converter is automatically stopped in response to completion of the charging of the main capacitor 9, the charge stored in the main capacitor 9 is only decreased by leak after the oscillation has been stopped and therefore, it is necessary that, as far as possible, no load be connected to the secondary side of the booster transformer 4. For this reason, power is supplied to the auxiliary trigger circuit for the thyristor 30 from the primary side of the booster transformer.
FIG. 3 shows a second embodiment provided by changing the circuit block A of FIG. 1.
In the first embodiment, during pop-up of the flashlight emitting portion 108, the transistor 13 is turned off by turn-on of the display tube 35 to open the base circuit of the transistor 3 and automatically stop the oscillation of the DC/DC converter. In this case, the charge in the main capacitor 9 is consumed by the turn-on current of the display tube 35 and sooner or later, the charging voltage of the main capacitor 9 will become unable to maintain the display tube 35 turned on. Therefore, the display tube 35 will be turned off and the transistor 13 will be again turned on to restart the oscillation of the DC/DC converter. It is apparent that if such condition is repeated, the power source 1 will be consumed. The second embodiment shown in FIG. 3 improves this.
First, the switch 14 is closed by pop-up of the flashlight emitting portion 108. The switch 12 remains closed until the preparation operation for the next flashlight photography is started on the camera side. Transistor 37 is a transistor for forcible oscillation parallel-connected to the switch 8.
Now, when the change-over switch 17 selects the terminal 17b, the charging of the main capacitor 9 progresses and the display tube 35 is turned on, whereupon transistor 16 is turned on. Thereby, transistor 42 is turned on through a resistor 45, transistor 39 is turned on through a resistor 40, and transistor 37 is turned off. Accordingly, the oscillation of DC/DC converter is automatically stopped by completion of the charging. Next, when the display tube 35 is turned off, the transistor 16 maintains its ON state because it is biased through a resistor 46. That is, the present embodiment is one in which by making the transistors 16 and 42 into a bistable circuit, the base circuit of transistor 3 is opened at a stage whereat the display tube 35 has been turned on, and thereafter reoscillation does not occur even if the display tube 35 is turned off. The bistable circuit may also be achieved by the use of thyristors.
Switch 12, which operates in the same manner as that described in connection with FIG. 1, is used for releasing the latch of the bistable circuit. That is, when the switch 12 is opened and transistor 16 turned off in response to the preparation for the next flashlight photography, transistor 39 is turned off and transistor 37 is turned on through resistor 38, whereby oscillation is again started. Thus, the switch 12 also serves to restart the oscillation after flashlight emission, but in FIG. 3, the restarting of the oscillation is designed to take place only during pop-up the flashlight emitting portion.
In the foregoing embodiments, the switch 8 is momentarily closed in response to the retraction of the cover member 100 out of the phototaking light path of the lens, whereas this is not restrictive but the switch 8 may be closed in response to pop-up of the flashlight emitting portion 108.
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A flash device for photography includes a DC/DC converter for boosting a DC power source voltage and applying a voltage to a main capacitor for supplying an energy for driving a flashlight tube. The converter has control means operative in response to the trigger operation by a start operating switch to detect any reduction in the charging current of the main capacitor and stop said operation. The flash device is provided with another switch means for enabling the operation of the converter independently of the start operating switch. Said another switch means is operative to operate the converter until the charging voltage of the main capacitor reaches a sufficient value to drive the flashlight tube.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 10/946,458, filed Sep. 20, 2004 now U.S. Pat. No. 7,241,596, which is a continuation of U.S. patent application Ser. No. 10/293,236, filed Nov. 12, 2002 now abandoned, which is a continuation of U.S. patent application Ser. No. 08/826,538, filed Apr. 3, 1997, now U.S. Pat. No. 6,485,903, which is a continuation of U.S. patent application Ser. No. 08/435,509, filed May 5, 1995, abandoned, all of which are incorporated herein by reference.
BACKGROUND
This invention relates generally to the field of nucleic amplification and probing, and more particularly, to methods and compositions for performing PCR and probe hybridization using a single reagent mixture.
Nucleic acid amplification techniques provide powerful tools for the study of genetic material. The polymerase chain reaction (PCR) in particular has become a tool of major importance finding applications in cloning, analysis of genetic expression, DNA sequencing, genetic mapping, drug discovery, criminal forensics, and the like, e.g., Innis et al. in PCR Protocols A guide to Methods and Applications, Academic Press, San Diego (1990); and U.S. Pat. Nos. 4,683,195, 4,683,202.
For many important applications, in addition to amplifying a target nucleic acid sequence, it is desirable to further characterize such sequence by treatment with a nucleic acid hybridization probe, i.e., a labeled single stranded polynucleotide which is complementary to all or part of the target sequence, e.g., Nucleic Acid Hybridization, Hames et al. Eds., IRL Press, Oxford (1985). Probe hybridization may provide additional sequence selectivity over simple PCR amplification as well as allowing for the characterization of multiple sequence sites within the target nucleic acid sequence in an independent manner.
Traditionally, PCR and probe hybridization processes have been performed as separate operations. However, it is highly desirable to perform both the PCR and the probe hybridization reactions in a combined manner using a single reagent mixture containing both PCR reagents and probing reagents. There are several advantages realized by combining the PCR and the probing process: (i) only a single reagent addition step is required, thereby allowing the combined reactions to proceed without having to open up the reaction tube, thereby reducing the opportunity for sample mix-up and sample contamination; (ii) fewer reagents are needed; (iii) fewer reagent addition steps are required, making automation more straight forward; and, (iv) in the case of in situ methods, there is no requirement to take apart a sample containment assembly used to protect the integrity of the cellular sample during thermocycling.
One existing method which combines PCR with hybridization probing in a single reaction is the technique know as “Taqman”, e.g., Holland et al, Proc. Natl. Acad. Sci. USA 88: 7276-7280 (1991). In the Taqman assay, an oligonucleotide probe, nonextendable at the 3′ end, labeled at the 5′ end, and designed to hybridize within the target sequence, is introduced into the PCR reaction. Hybridization of the probe to a PCR reaction product strand during amplification generates a substrate suitable for the exonuclease activity of the PCR polymerase. Thus, during amplification, the 5′→3′ exonuclease activity of the polymerase enzyme degrades the probe into smaller fragments that can be differentiated from undegraded probe. While a significant improvement over prior methods, the Taqman assay has a number of important drawbacks that limit its utility including (i) the requirement that the polymerase enzyme used for the PCR must include a 5′→3′ exonuclease activity, (ii) the 5′→3′ exonuclease activity must be able to efficiently digest a dye-labeled nucleotide, and (iii) the detectable product of the digestion is a small, rapidly diffusable species which may impact the ability to spatially locate the target sequence when applied to in situ methods.
A second existing method which combines PCR with probing in a single reaction is that disclosed by Higuchi et al. in Biotechnology, 10: 413-417 (1992). In this method, ethidium bromide is added to the PCR reaction and, since the fluorescence of the ethidium bromide increases in the presence of double stranded DNA, an increase in fluorescence can be correlated with the accumulation of double stranded PCR product. However, this method does not provide any sequence specificity beyond the PCR reaction and is limited to the detection of a single sequence site within the target nucleic acid sequence.
A third method which allows for combined amplification and probing steps is that of Bagwell in EP 0601889A2. The probe in Bagwell's method includes a nucleotide sequence which has (i) a segment complementary to the target nucleic acid and (ii) a segment capable of forming one or more hairpins. The probe also includes covalently attached fluorescer and a quencher molecules located such that when a hairpin is formed, the fluorescer and quencher are in close enough proximity to allow resonance energy transfer between them. This method has the significant short coming that it limits the possible probe sequences to those capable of forming a hairpin structure. Moreover, the kinetics and thermodynamics of probe-target binding will be unfavorably affected by the presence of the hairpin structure.
SUMMARY
The present invention relates generally to our discovery of methods and reagents useful for the combined amplification and hybridization probe detection of amplified nucleic acid target sequence in a single reaction vessel using a single reagent.
An object of our invention is to provide methods and reagents for the amplification and probe detection of amplified target sequences wherein the amplification and probing steps are performed in a combined manner such that no reagent additions are required subsequent to the amplification step.
A further object of our invention is to provide methods and reagents for the amplification and probe detection of amplified target sequences located within cells or tissue sections wherein there is no need to disassemble a containment assembly between the amplification and probing steps.
Another object of our invention is to provide methods and reagents for the amplification and probe detection of amplified target sequences wherein a single reagent mixture is used for both the amplification and probing steps.
A further object of our invention is to provide methods and reagents for the amplification and probing of amplified target sequences located within cells or tissue sections wherein no washing step is required between the amplification and probing steps.
Another object of our invention is to provide a probe composition for use in the above methods that has detectabley different fluorescence characteristics depending on whether it is in a double stranded state, e.g., hybridized to a complementary target sequence, or whether it is in a single stranded state.
Yet another object of our invention is to provide oligonucleotide probes which are resistant to the 5′→3′ exonuclease activity of polymerase enzymes.
Another object of our invention is to provide labeled probes in which, at the time of detection, the label is attached to a large, slowly diffusing species, i.e., a species having a size greater than or equal to the size of the probe.
A further object of our invention is to provide probes which do not require hairpin structures in order to provide a differential signal between double stranded and single stranded states.
Another object of our invention is to provide methods and reagents for the amplification and probe detection of amplified target sequences wherein the polymerase is not required to have 5′→3′ exonuclease activity.
Yet another object of our invention is to provide methods and reagents for the amplification and probe detection of amplified target sequences wherein multiple sequence sites can be detected within a single target sequence.
Still another object of our invention is to provide various reagent kits useful for the practice of the aforementioned methods.
The foregoing and other objects of the invention are achieved by, in one aspect, an oligonucleotide probe which is made up of an oligonucleotide capable of hybridizing to a target polynucleotide sequence. The oligonucleotide is modified such that the 5′ end is rendered impervious to digestion by the 5′→3′ exonuclease activity of a polymerase, and the 3′ end is rendered impervious to the 5′→3′ extension activity of a polymerase. Furthermore, the oligonucleotide probe includes a fluorescer molecule attached to a first end of the oligonucleotide, and a quencher molecule attached to a second end of the oligonucleotide such that the quencher molecule substantially quenches the fluorescence of the fluorescer molecule whenever the oligonucleotide probe is in a single-stranded state and such that the fluorescer is substantially unquenched whenever the oligonucleotide probe is in a double-stranded state. Alternatively, the fluorescer and quencher are separated by at least 18 nucleotides.
In a second aspect, the invention provides a first method for performing combined PCR amplification and hybridization probing. In the method, a target nucleic acid sequence is contacted with PCR reagents, including at least two PCR primers, a polymerase enzyme, and an oligonucleotide probe of the invention as described above. This mixture is then subjected to thermal cycling, the thermal cycling being sufficient to amplify the target nucleic acid sequence specified by the PCR reagents.
In a third aspect, the invention provides a second method for performing combined PCR amplification and hybridization probing wherein the target nucleic acid sequence is contacted with PCR reagents, including at least two PCR primers and a polymerase enzyme substantially lacking any 5′→3′ exonuclease activity, and an oligonucleotide probe. The oligonucleotide probe includes a fluorescer molecule attached to a first end of the oligonucleotide and a quencher molecule attached to a second end of the oligonucleotide such that quencher molecule substantially quenches the fluorescence of the fluorescer molecule whenever the oligonucleotide probe is in a single-stranded state and such that the fluorescer is substantially unquenched whenever the oligonucleotide probe is in a double-stranded state. In addition, the 3′ end of the probe is rendered impervious to the 5′→3′ extension activity of a polymerase. The target nucleic acid sequence, the oligonucleotide probe, and the PCR reagents are subjected to thermal cycling sufficient to amplify the target nucleic acid sequence specified by the PCR reagents.
In one preferred embodiment, rather than requiring the polymerase enzyme to be lacking any 5′→3′ exonuclease activity, an exonuclease activity inhibitor is added to the reaction, the inhibitor being sufficient to inhibit the 5′→3′ exonuclease activity of the polymerase at a probe hybridization temperature.
In a second preferred embodiment, rather than requiring the polymerase enzyme to be lacking any 3′→5′ exonuclease activity, or rather than adding an exonuclease activity inhibitor, the 3′→5′ exonuclease activity of the polymerase is deactivated prior to detecting the probe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic diagram of a first preferred combined PCR and probe hybridization method wherein a temperature difference between the melting temperature (T m ) of the probe and the reaction temperature of the PCR polymerization step is used to prevent the probe from interfering with the PCR polymerization step and digestion of the probe.
FIG. 2 shows a schematic diagram of a second preferred combined PCR and probe hybridization method wherein a strand displacer is used to prevent the probe from interfering with the PCR polymerization step and digestion of the probe.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the invention. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications, and equivalents which may be included within the invention as defined by the appended claims.
1. PCR AND IN SITU PCR
As used herein, the term “PCR reagents” refers to the chemicals, apart from the target nucleic acid sequence, needed to perform the PCR process. These chemicals generally consist of five classes of components: (i) an aqueous buffer, (ii) a water soluble magnesium salt, (iii) at least four deoxyribonucleotide triphosphates (dNTPs), (iv) oligonucleotide primers (normally two primers for each target sequence, the sequences defining the 5′ ends of the two complementary strands of the double-stranded target sequence), and (v) a polynucleotide polymerase, preferably a DNA polymerase, more preferably a thermostable DNA polymerase, i.e., a DNA polymerase which can tolerate temperatures between 90° C. and 100° C. for a total time of at least 10 min without losing more than about half its activity
The four conventional dNTPs are thymidine triphosphate (dTTP), deoxyadenosine triphosphate (dATP), deoxycitidine triphosphate (dCTP) and deoxyguanosine triphosphate (dGTP). These conventional triphosphates may be supplemented or replaced by dNTPs containing base analogues which Watson-Crick base pair like the conventional four bases, e.g., deoxyuridine triphosphate (dUTP).
“In situ PCR” refers to PCR amplification performed in fixed cells, such that specific amplified nucleic acid is substantially contained within a cell or subcellular structure which originally contained the target nucleic acid sequence. The cells may be in aqueous suspension or may be part of a tissue sample, e.g., histochemical section, or a cytochemical smear. As used herein, the term “histochemical section” refers to a solid sample of biological tissue which has been frozen or chemically fixed and hardened by embedding in a wax or plastic, sliced into a thin sheet (typically several microns thick), and attached to a solid support, e.g., a microscope slide, and the term “cytochemical smear” refers to a suspension of cells, e.g., blood cells, which has been chemically fixed and attached to a microscope slide. Preferably, the cells will have been rendered permeable to PCR reagents by proteinase digestion, by liquid extraction with a surfactant or organic solvent, or other like permeablization methods.
As used herein, the term “fixed cells” refers to a sample of biological cells which has been chemically treated to strengthen cellular structures, particularly membranes, against disruption by solvent changes, temperature changes, mechanical stress or drying. Cells may be fixed either in suspension our as part of a tissue sample. Cell fixatives generally are chemicals which crosslink the protein constituents of cellular structures, most commonly by reacting with protein amino groups. Preferred fixatives include buffered formalin, 95% ethanol, fomaldehyde, paraformaldehyde, and glutaraldehyde. The permeability of fixed cells can be increased by treatment with proteinases, or with surfactants or organic solvents which dissolve membrane lipids.
2. OLIGONUCLEOTIDE PROBES
The term “oligonucleotide” as used herein includes linear oligomers of natural or modified monomers or linkages, including deoxyribonucleotides, ribonucleotides, and the like, capable of specifically binding to a target polynucleotide by way of a regular pattern of monomer-to-monomer interactions, such as Watson-Crick type of base pairing, or the like. Usually monomers are linked by phosphodiester bonds or analogs thereof to form oligonucleotides ranging in size from a few monomeric units, e.g. 3-4, to several tens of monomeric units. Whenever an oligonucleotide is represented by a sequence of letters, such as “ATGCCTG,” it will be understood that the nucleotides are in 5′→3′ order from left to right and that “A” denotes deoxyadenosine, “C” denotes deoxycytidine, “G” denotes deoxyguanosine, and “T” denotes thymidine, unless otherwise noted. Analogs of phosphodiester linkages include phosphorothioate, phosphoranilidate, phosphoramidate, and the like.
As used herein, “nucleotide” includes the natural nucleotides, including 2′-deoxy and 2′-hydroxyl forms, e.g. as described in Kornberg and Baker, DNA Replication, 2nd Ed. (Freeman, San Francisco, 1992). “Analogs” in reference to nucleotides includes synthetic nucleotides having modified base moieties and/or modified sugar moieties, e.g. described by Scheit, Nucleotide Analogs (John Wiley, New York, 1980); Uhlman and Peyman, Chemical Reviews, 90: 543-584 (1990), or the like, with the only proviso that they are capable of specific hybridization. Such analogs include synthetic nucleotides designed to enhance binding properties, reduce degeneracy, increase specificity, reduce activity as enzyme substrates, and the like.
Oligonucleotides of the invention can be synthesized by a number of approaches, e.g. Ozaki et al, Nucleic Acids Research, 20: 5205-5214 (1992); Agrawal et al, Nucleic Acids Research, 18: 5419-5423 (1990); or the like. The oligonucleotide probes of the invention are conveniently synthesized on an automated DNA synthesizer, e.g. a Perkin-Elmer (Foster City, Calif.) Model 392 or 394 DNA/RNA Synthesizer, using standard chemistries, such as phosphoramidite chemistry, e.g. disclosed in the following references: Beaucage and lyer, Tetrahedron, 48: 2223-2311 (1992); Molko et al, U.S. Pat. No. 4,980,460; Koster et al, U.S. Pat. No. 4,725,677; Caruthers et al, U.S. Pat. Nos. 4,415,732; 4,458,066; and 4,973,679; and the like. Alternative chemistries, e.g. resulting in non-natural backbone groups, such as phosphorothioate, phosphoramidate, and the like, may also be employed provided that the hybridization efficiencies of the resulting oligonucleotides are not adversely affected. Preferably, the oligonucleotide probe is in the range of 15-150 nucleotides in length. More preferably, the oligonucleotide probe is in the range of 18-30 nucleotides in length. The precise sequence and length of an oligonucleotide probe of the invention depends in part on the nature of the target nucleic acid sequence to which it hybridizes. The binding location and length may be varied to achieve appropriate annealing and melting properties for a particular embodiment. Guidance for making such design choices can be found in many of the above-cited references describing the “Taqman” type of assays.
Preferably, the 3′ terminal nucleotide of the oligonucleotide probe is rendered incapable of extension by a nucleic acid polymerase. Such blocking may be carried out by the attachment of a fluorescer or quencher molecule to the terminal 3′ carbon of the oligonucleotide probe by a linking moiety, or by making the 3′-terminal nucleotide a dideoxynucleotide. Alternatively, the 3′ end of the oligonucleotide probe is rendered impervious to the 5′→3′ extension activity of a polymerase by including one or more modified internucleotide linkages into the 3′ end of the oligonucleotide. Minimally, the 3′-terminal internucleotide linkage must be modified, however, up to all the internucleotide linkages may be modified. Such internucleotide modifications may include phosphorothioate linkeages, e.g., Oligonucleotides and Analogs, Chaps. 4 and 5, IRL Press, New York (1991); methylyphosphonate linkages, Oligonucleotides and Analogs, Chap. 6, IRL Press, New York (1991); boranophosphate linkages, e.g., Shaw et al., Methods Mol. Biol. 20: 225-43 (1993); and other like polymerase resistant internucleotide linkages. An alternative method to block 3′ extension of the probe is to form an adduct at the 3′ end of the probe using mitomycin C or other like antitumor antibiotics, e.g., Basu et al., Biochemistry, 32: 4708-4718 (1993).
In an important aspect of one embodiment of the present invention, the oligonucleotide probe is rendered impervious to degradation by the 5′→3′ exonuclease activity of a nucleic acid polymerase. Preferably, the 5′ end of the oligonucleotide probe is rendered impervious to digestion by including one or more modified internucleotide linkages into the 5′ end of the oligonucleotide. Minimally, the 5′-terminal internucleotide linkage must be modified, however, up to all the internucleotide linkages in the oligonucleotide may be modified. Such internucleotide modifications may include modified linkages of the type used in the synthesis of anti-sense oligonucleotides. Examples of such nuclease resistant linkages include phosphorothioate linkages, e.g., Oligonucleotides and Analogs, Chaps. 4 and 5, IRL Press, New York (1991); methylyphosphonate linkages, Oligonucleotides and Analogs, Chap. 6, IRL Press, New York (1991); boranophosphate linkages, e.g., Shaw et al., Methods Mol. Biol. 20: 225-43 (1993); polyamide nucleic acid (PNA) linkages, e.g., Nielsen et al., Science, 254: 1497-1500 (1991), and other like exonuclease resistant linkages. Alternatively, a peptide molecule is be attached to the 5′ end of the probe in an manner anaologus to that of Soukchareun et al. in Bioconjugate Chemistry, 6: 43-53 (1995).
In another important aspect of the oligonucleotide probes of the present invention, the probes include fluorescer and quencher molecules attached to the oligonucleotide. As used herein, the terms “quenching” or “fluorescence energy transfer” refer to the process whereby when a fluorescer molecule and a quencher molecule are in close proximity, whenever the fluorescer molecule is excited, a substantial portion of the energy of the excited state nonradiatively transfers to the quencher where it either dissipates nonradiatively or is emitted at a different emission wavelength than that of the fluorescer.
It is well known that the efficiency of quenching is a strong function of the proximity of the fluorescer and the quencher, i.e., as the two molecules get closer, the quenching efficiency increases. As quenching is strongly dependent on the physical proximity of the reporter molecule and quencher molecule, it has been assumed that the quencher and reporter molecules must be attached to the probe within a few nucleotides of one another, usually with a separation of about 6-16 nucleotides, e.g. Lee et al. Nucleic Acids Research, 21: 3761-3766 (1993); Mergny et al, Nucleic Acids Research, 22: 920-928 (1994); Cardullo et al, Proc. Natl. Acad. Sci., 85: 8790-8794 (1988); Clegg et al, Proc. Natl. Acad. Sci., 90: 2994-2998 (1993); Ozaki et al, Nucleic Acids Research, 20: 5205-5214 (1992); and the like. Typically, this separation is achieved by attaching one member of a reporter-quencher pair to the 5′ end of the probe and the other member to a base 6-16 nucleotides away.
However, it has been recognized as part of the present invention that by placing the fluorescer and quencher molecules at seemingly remote locations on the oligonucleotide, differential quenching can be seen between the single stranded state and the double stranded state, i.e., hybridized state, of the oligonucleotide probe, e.g., Bagwell et al., Nucleic Acids Research, 22(12): 2424-2425 (1994); Bagwell, EP 0 601 889 A2. The fluorescence signals can differ by as much as a factor of 20 between the single stranded and double stranded states when the fluorescer and quencher are separated by 20 bases. This effect is most probably due to the fact that in the single stranded state, the oligonucleotide exists as a flexible random coil structure which allows the ends of the oligonucleotide to be in close proximity, while, in the double stranded state, the oligonucleotide exists as a rigid, extended structure which separates the fluorescer and quencher. Thus, using this arrangement, one sees relatively efficient quenching of the fluorescer when the oligonucleotide probe is in the single stranded or unhybridized state and relatively inefficient quenching of the fluorescer when the oligonucleotide probe is in the double stranded or hybridized state.
Preferably, fluorescer molecules are fluorescent organic dyes derivatized for attachment to the terminal 3′ carbon or terminal 5′ carbon of the probe via a linking moiety. Preferably, quencher molecules are also organic dyes, which may or may not be fluorescent, depending on the embodiment of the invention. For example, in a preferred embodiment of the invention, the quencher molecule is fluorescent. Generally, whether the quencher molecule is fluorescent or simply releases the transferred energy from the fluorescer by non-radiative decay, the absorption band of the quencher should substantially overlap the fluorescent emission band of the fluorescer molecule. Non-fluorescent quencher molecules that absorb energy from excited fluorescer molecules, but which do not release the energy radiatively, are referred to herein as chromogenic molecules.
There is a great deal of practical guidance available in the literature for selecting appropriate fluorescer-quencher pairs for particular probes, as exemplified by the following references: Clegg (cited above); Wu et al., Anal. Biochem., 218: 1-13 (1994). Pesce et al, editors, Fluorescence Spectroscopy (Marcel Dekker, New York, 1971); White et al, Fluorescence Analysis: A Practical Approach (Marcel Dekker, New York, 1970); and the like. The literature also includes references providing exhaustive lists of fluorescent and chromogenic molecules and their relevant optical properties for choosing fluorescer-quencher pairs, e.g. Berlman, Handbook of Fluorescence Sprectra of Aromatic Molecules, 2nd Edition (Academic Press, New York, 1971); Griffiths, Colour and Consitution of Organic Molecules (Academic Press, New York, 1976); Bishop, editor, Indicators (Pergamon Press, Oxford, 1972); Haugland, Handbook of Fluorescent Probes and Research Chemicals (Molecular Probes, Eugene, 1992); Pringsheim, Fluorescence and Phosphorescence (Interscience Publishers, New York, 1949); and the like. Further, there is extensive guidance in the literature for derivatizing fluorescer and quencher molecules for covalent attachment via common reactive groups that can be added to an oligonucleotide, as exemplified by the following references: Haugland (cited above); Ullman et al, U.S. Pat. No. 3,996,345; Khanna et al, U.S. Pat. No. 4,351,760; and the like.
Exemplary fluorescer-quencher pairs may be selected from xanthene dyes, including fluoresceins, and rhodamine dyes. Many suitable forms of these compounds are widely available commercially with substituents on their phenyl moieties which can be used as the site for bonding or as the bonding functionality for attachment to an oligonucleotide. Another group of fluorescent compounds are the naphthylamines, having an amino group in the alpha or beta position. Included among such naphthylamino compounds are 1-dimethylaminonaphthyl-5-sulfonate, 1-anilino-8-naphthalene sulfonate and 2-p-touidinyl-6-naphthalene sulfonate. Other dyes include 3-phenyl-7-isocyanatocoumarin, acridines, such as 9-isothiocyanatoacridine and acridine orange; N-(p-(2-benzoxazolyl)phenyl)maleimide; benzoxadiazoles, stilbenes, pyrenes, and the like.
Preferably, fluorescer and quencher molecules are selected from fluorescein and rhodamine dyes. These dyes and appropriate linking methodologies for attachment to oligonucleotides are described in many references, e.g. Khanna et al (cited above); Marshall, Histochemical J., 7: 299-303 (1975); Mechnen et al, U.S. Pat. No. 5,188,934; Menchen et al, European patent application 87310256.0; and Bergot et al, International application PCT/US90/05565. The latter four documents are hereby incorporated by reference.
There are many linking moieties and methodologies for attaching fluorescer or quencher molecules to the 5′ or 3′ termini of oligonucleotides, as exemplified by the following references: Eckstein, editor, Oligonucleotides and Analogues: A Practical Approach (IRL Press, Oxford, 1991); Zuckerman et al, Nucleic Acids Research, 15: 5305-5321 (1987)(3′ thiol group on oligonucleotide); Sharma et al, Nucleic Acids Research, 19: 3019 (1991)(3′ sulfhydryl); Giusti et al, PCR Methods and Applications, 2: 223-227 (1993) and Fung et al, U.S. Pat. No. 4,757,141 (5′ phosphoamino group via Aminolink™ II available from Applied Biosystems, Foster City, Calif.); Stabinsky, U.S. Pat. No. 4,739,044 (3′ aminoalkylphosphoryl group); Agrawal et al, Tetrahedron Letters, 31: 1543-1546 (1990)(attachment via phosphoramidate linkages); Sproat et al, Nucleic Acids Research, 15: 4837 (1987)(5′ mercapto group); Nelson et al, Nucleic Acids Research, 17: 7187-7194 (1989)(3′ amino group); and the like.
Preferably, commercially available linking moieties are employed that can be attached to an oligonucleotide during synthesis, e.g. available from Clontech Laboratories (Palo Alto, Calif.).
Rhodamine and fluorescein dyes are also conveniently attached to the 5′ hydroxyl of an oligonucleotide at the conclusion of solid phase synthesis by way of dyes derivatized with a phosphoramidite moiety, e.g. Woo et al, U.S. Pat. No. 5,231,191; and Hobbs, Jr. U.S. Pat. No. 4,997,928.
3. COMBINED PCR AMPLIFICATION AND PROBE HYBRIDIZATION
There are three key issues which must be addressed when performing combined PCR and probe hybridization assays: (i) the oligonucleotide probe should not block or otherwise interfere with the PCR polymerization step thereby reducing the stepwise efficiency of the amplification, where as used herein, the term “polymerization step” refers to the step in the PCR process in which the primers are extended from their 3′ ends by incorporation of nucleotide bases by a polymerase-mediated reaction; (ii) the oligonucleotide probe must not be digested by the 5′→3′ exonuclease activity of the polymerase enzyme; and (iii) the probe should be incapable of 5′→3′ extension by the polymerase.
In one preferred embodiment of the present invention, the probe is protected from interfering with the PCR polymerization step by designing the probe such that its melting temperature is above the temperature of the PCR polymerization step. As used herein, the term “melting temperature” is defined as a temperature at which half of the probe is hybridized to a target sequence, i.e., in a double stranded state, and half is in unhybridized, i.e., in a single stranded state. Preferably, the melting temperature of the probe is between 40° C. and 55° C., and the melting temperature of the PCR primers is between 55° C. and 70° C.
Referring to FIG. 1 , during the PCR polymerization step, the probe is unhybridized, i.e., in a single stranded state, and thereby quenched. Moreover, because the probe is not bound to the target sequence, the PCR polymerization can proceed without interference from the probe. Next, during the hybridization step, the temperature is reduced to a hybridization temperature, preferably a temperature at or below the T m of the probe, causing the probe to hybridize to the target. The hybridization of the probe causes a reduction in the amount of quenching, resulting in a measurable signal which is indicative of probe hybridization to the target sequence, such signal also providing quantitative information as to the mount of target sequence present. During the hybridization step, the probe will not be digested by the exonuclease activity of the polymerase because, as discussed above, the probe has been designed to be impervious to the 5′→3′ exonuclease activity of the polymerase.
In a variation on the above described T m mediated combined PCR and probe hybridization method, rather than using a probe which is impervious to the 5′→3′ exonuclease activity of the polymerase, digestion of the probe during the hybridization step is prevented by using a polymerase which lacks a 5′→3′ exonuclease activity. Examples of such 5′→3′ minus polymerases include DNA polymerase I Klenow fragment, T4 DNA polymerase, and T7 DNA polymerase, and other like 5′→3′ exonuclease minus DNA polymerases, e.g., Amershan Life Science, Inc., Arlington Heights, Ill.
In a second variation of the above described T m mediated combined PCR and probe hybridization method, rather than using a probe which is impervious to the 5′→3′ exonuclease activity of the polymerase or using an exonuclease-minus polymerase to protect the probe from exonuclease digestion, the polymerase is rendered inactive with respect to its exonuclease activity during the hybridization step. Such inactivation can be achieved in a number of ways including (i) introducing a temperature sensitive inhibitor into the reaction which will inhibit the 5′→3′ exonuclease activity of the polymerase at the hybridization temperature, e.g., a solid adsorbent, a specific antibody molecule, or other like reversible or irreversible polymerase inhibitors; (ii) using a polymerase whose activity is greatly reduced at the hybridization temperature; or (iii) introducing an enzyme deactivation step prior to the hybridization step which irreversibly kills the polymerase enzyme, i.e., an extended period at high temperature.
In a second preferred embodiment of the present invention, the probe is prevented from interfering with the PCR polymerization step by including a strand displacer into the reaction, where, as used herein, the term “strand displacer” refers to an agent capable of causing the displacement of an oligonucleotide probe from a target to which it is hybridized, e.g., a DNA helicase, e.g., Howard et al., Proc. Natl. Acad. Sci. USA 91: 12031-12035 (1994), or a single-stranded binding protein, E. G. Zijderveld, Journal of Virology 68(2): 1158-1164 (1994). Referring to FIG. 2 , in this embodiment, during the polymerization step, the strand displacer displaces the probe from the template strand thereby allowing the polymerization step to proceed without interference from the probe. Then, in order to allow hybridization of the probe during the hybridization step, the strand displacer is rendered inactive. Such inactivation can be achieved in a number of ways including those described above with reference to inactivation of exonuclease activity. Generally, the strand displacement activity of a strand displacer is higher for longer oligonucleotide duplexes, thus, the PCR primers themselves are not susceptible to strand displacement during the PCR reaction.
4. EXAMPLES
The Invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the invention.
Example 1
Comparison of Fluorescence Emissions of Probes in Single Stranded and Double Stranded States
Linker arm nucleotide (“LAN”) phosphoramidite was obtained from Glen Research. Standard DNA phosphoramidites, 6-carboxyfluorescein (“6-FAM”) phosphoramidite, 6-carboxytetramethylrhodamine succinimidyl ester (“TAMRA NHS ester”), and Phosphalink™ for attaching a 3′ blocking phosphate were obtained from Perkin-Elmer, Applied Biosystems Division. Oligonucleotide synthesis was performed on a model 394 DNA Synthesizer (Applied Biosystems). Oligonucleotides were purified using Oligo Purification Cartridges (Applied Biosystems).
Doubly labeled probes were synthesized with 6-FAM-labeled phosphoramidite at the 5′ end, LAN replacing one of the T's in the oligonucleotide sequence, and Phosphalink™ at the 3′ end. Following deprotection and ethanol precipitation, TAMRA NHS ester was coupled to the LAN-containing oligonucleotide in 250 mM Na-bicarbonate buffer (pH 9.0) at room temperature. Unreacted dye was removed by passage over a PD-10 Sephadex column. Finally, the doubly labeled probe was purified by preparative HPLC using standard protocols.
The oligonucleotide sequences of the probes and their complements are shown in Table 1. As used herein, the term “complement” refers to an oligonucleotide sequence which is capable of hybridizing specifically with a probe sequence.
TABLE 1
Probe/
Complement
Sequence
1
ATGCCCTCCCCCATGCCATCCTGCGT
(SEQ ID NO:1)
1
AGACGCAGGATGGCATGGGGGAGGGCATAC
(Complement)
(SEQ ID NO:2)
2
CGCCCTGGACTTCGAGCAAGAGAT
(SEQ ID NO:3)
2
CCATCTCTTGCTCGAAGTCCAGGGCGAC
(Complement)
(SEQ ID NO:4)
3
TCGCATTACTGATCGTTGCCAACCAGT
(SEQ ID NO:5)
3
GTACTGGTTGGCAACGATCAGTAATGCGATG
(Complement)
(SEQ ID NO:6)
4
CGGATTTGCTGGTATCTATGACAAGGAT
(SEQ ID NO:7)
4
TTCATCCTTGTCATAGATACCAGCAAATCCG
(Complement)
(SEQ ID NO:8)
Four pairs of probes were studied. For each pair, one probe has TAMRA attached to an internal nucleotide, the other has TAMRA attached to the 3′ end nucleotide, and both probes have 6-FAM attached to the 5′ end. To measure the fluorescence of the probes in a single stranded state, fluorescence emissions at 518 nm were measured using solutions containing a final concentration of 50 nM probe, 10 mM Tris-HCl (pH 8.3), 50 mM KCl, and 10 mM MgCl 2 . To measure the fluorescence of the probes in a double stranded state, the solutions additionally contained 100 M complement oligonucleotide. Before addition of the MgCl 2 , 120 □l of each sample was heated at 95° C. for 5 min. Following the addition of 80 □l of 25 mm MgCl 2 , each sample was allowed to cool to room temperature and the fluorescence emissions were measured. Reported values are the average of three measurements. Table 2 gives the results of fluorescence measurements of the indicated probes in single and double stranded states. As can be seen from the data in Table 2, for probes having the fluorescer and quencher at opposite ends of the oligonucleotide, hybridization caused a dramatic increase in the degree of differential quenching over that seen when the fluorescer and quencher were closer together. For longer probes, we would expect that there exists an optimum separation between the fluorescer and the quencher such that rather than placing the fluorescer and quencher at oppisite ends, they are both located internally but separated by some optimum distance.
TABLE 2
TAMRA
Differential
Probe
Location a
Quenching b
1
7
2.5
1
26
11.8
2
6
3.7
2
24
19.2
3
7
2.0
3
27
8.0
4
10
5.3
a The TAMRA location is expressed as the number of nucleotides from the 5′ end of the oligonucleotide in a 5′ to 3′ direction.
b Differential quenching is defined as the fluorescence emission intensity of the probe in the double stranded state divided by the fluorescence emission intensity of the probe in the single stranded state.
Although only a few embodiments have been described in detail above, those having ordinary skill in the molecular biology art will clearly understand that many modifications and variations are possible in the preferred embodiments without departing from the teachings thereof.
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An oligonucleotide probe is disclosed, the probe including an oligonucleotide, a fluorescer molecule attached to a first end of the oligonucleotide and a quencher molecule attached to the opposite end of the oligonucleotide. The probe is rendered impervious to digestion by the 5′→3′ exonuclease activity of a polymerase and the 5′→3′ extension of by a polymerase. The invention also includes methods for performing combined PCR amplification and hybridization probing, one such method including the steps of contacting a target nucleic acid sequence with PCR reagents and an oligonucleotide probe as described above, and subjecting these reagents to thermal cycling. One preferred refinement of the above method further includes the addition of a strand displacer to facilitate amplification. Additional similar combined PCR hybridization methods are disclosed, such methods not requiring probes having their 5′ ends protected, wherein (i) the polymerase lacks 5′→3′ exonuclease activity, (ii) a 5′→3′ exonuclease inhibitor is included, and (iii) an exonuclease deactivation step is performed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims the benefits of priority of commonly assigned Canadian Patent Application no. 2,668,501, entitled “Extracteur d′ancrage à angle variable” and filed at the Canadian Patent Office on June 1 st , 2009.
FIELD OF THE INVENTION
[0002] The present invention is related to device used to remove anchorage or the like from the ground.
BACKGROUND OF THE INVENTION
[0003] The present invention is related to devices used to remove anchorage or post inserted in the ground. Currently, non-motorized or motorized devices are used for this purpose, but users of these devices are rather dissatisfied with the performance or conditions of use.
[0004] Regarding the motorized devices, their advantage is the strength that can be generated but they are often bulky and heavy and consequently difficult to handle. In the specific environment of the assembly and dismantling of marquees or capital, hooks or anchorages used to secure the capital are often placed in confined spaces and a large device is awkward to use. These devices also require fuel to operate. Moreover, it is necessary to provide special equipment, such as a truck or trailer for moving these devices because of their size and weight.
[0005] The non-motorized devices that are currently used provide a limited force and a substantial effort is required from the user to remove the anchorages that are fixed in the ground. Indeed, the anchorages used to fix capitals are often inserted using pneumatic systems and in grounds such as asphalt or pavement composed of different materials pressed mechanically. Thus, these anchorages are firmly anchored in the ground. In addition, multiple anchorages are sometimes used, multiple anchorages are composed of a L-shaped structure which comprises several holes to receive several anchorages. Each of the anchorage is inserted individually in one of the hole of the L-shaped structure and the different anchorages will not have exactly the same orientation relatively to the ground. The different orientation of each of the anchorages creates a very high resistance to remove them all at the same time by exerting a force on the L-shaped structure. Because of this, each anchorage must be removed individually.
[0006] There is thus a need for a non-motorized device that has the advantages of both types of devices currently used, non-motorized and motorized. These advantages are ease of use, lightness of the system and the extraction force of the system independent of the strength of the user.
OBJECTS OF THE INVENTION
[0007] A first object of this invention is to provide a non-motorized extractor for anchorages.
[0008] A second object of this invention is to provide a non-motorized extractor developing a large extraction force.
[0009] Another object of the invention is to provide an extractor that may be positioned at different angles.
[0010] A fourth object of this invention is to provide an extractor having an extraction force that is generally independent of the strength of the user.
[0011] Another object of this invention is to provide an anchorage extractor that is easily transportable.
[0012] Another object of this invention is to provide an anchorage extractor that is foldable or that may be dismantled.
SUMMARY OF THE INVENTION
[0013] The aforesaid and other objectives of the present invention are realized by generally providing an extractor for anchorages or the like, the anchorages being installed in the ground and the anchorages having a longitudinal axis, the extractor comprising: a main body; a rack slidably connected to the main body; a shaft rotatively connected to the main body; a sprocket connected to the shaft, the sprocket cooperating with the rack; a first lever, wherein the actuation of the first lever cause the rotation of the shaft and of the sprocket; a connector adapted to cooperate with the anchorage, the connector being connected to the rack; a base connected to the main body, the base being in contact with the ground; wherein the actuation of the first lever drives the sprocket, and wherein the sprocket drives the rack upwardly and the rack pulls and remove the anchorage from the ground.
[0014] In a preferred embodiment, the extractor further comprises a driving wheel, the driving wheel being connected to the shaft, the driving wheel being rotated by actuating the first lever. The extractor further comprise a first lever-lock cooperating with the driving wheel, wherein the actuation of the first lever cause the first lever-lock to rotate the driving wheel, and wherein the first lever-lock transmit the rotation of the driving wheel to the shaft. The extractor comprises a second lever to release the first lever-lock. The extractor further comprises a second lever-lock cooperating with the driving wheel, the second lever-lock blocking the rotation of the driving wheel. The extractor comprises a release lever, the release lever releasing the second lever-lock from blocking the rotation of the driving wheel.
[0015] In a still further embodiment, aforesaid and other objectives of the present invention are realized by generally providing an extractor for anchorages or the like, the anchorages being installed in the ground and the anchorages having a longitudinal axis, the extractor comprising a main body, the main body having an elongated shape comprising a elongated cavity, wherein the main body may be disposed parallely to the longitudinal axis of the anchorage; a rack slidably connected into the cavity of the main body; a driving mechanism comprising: a shaft rotatively connected to the main body; a driving wheel connected to the shaft; a sprocket connected to the shaft, the sprocket cooperating with the rack; a first lever; a first lever-lock, the first lever-lock cooperating with the driving wheel, wherein the actuation of the first lever causes the first lever-lock to rotate the driving mechanism; a base connected to the main body, the base being in contact with the ground; a guiding member having an elongated shape, the guiding member being connected to the main body; a sliding structure adapted to slide along the guiding member, the sliding structure comprising an opening to receive the guiding member; a plurality of positioning holes, each of the positioning hole corresponding to an angular position of the main body; a locking member having an elongated shape, the locking member being adapted to cooperate with the positioning holes; wherein the actuation of the first lever drives the driving mechanism, and wherein the driving mechanism drives the rack.
[0016] The possibility to position the extractor at an angle substantially parallel to that of the anchorage provides a device that is more efficient. Indeed, when a force perpendicular to the ground is applied to remove an anchorage that is not perpendicular to the ground, only the force component that is in the same axis as the longitudinal axis of the anchorage is involved in the extraction. If the extraction force is applied in the same axis as the longitudinal axis as the anchorage, almost all this force acts as a force for extraction. Consequently, the device works more efficiently. The extractor of the present invention comprises a system to modify the angle of the main body. An example of such a system is illustrated later.
[0017] The support surface of the base of the anchorage extractor must be large enough to provide increased stability during extraction and thus prevent the extractor base to be destabilized during use. A triangular shape for the base of the support surface provides a good lateral stability. In addition, the support surface provided by the base is constant regardless of the angle of the main body. It is however to be understood that the shape of the base is not limited to a triangle and could be rectangular, polygonal, etc. . . . without departing from the scope of the present invention.
[0018] The device described in the present invention includes security mechanisms that are operated by levers or handles by the user. It is important to note that these security mechanisms are an example and they could be embodied by a different mechanism with the same utility, ie that will lock the extractor in a selected position.
[0019] The anchorages in the present invention may be devices inserted into the ground to keep objects in place or to provide an attachment point. These anchorages can be stakes for signs, anchorages for tents. It may also be, for example, stakes for trees, tent pegs, anchorages for tent, etc. . . . It should be noted that the extractor can be used to remove other devices inserted into the ground without limiting to the previous examples.
[0020] It has been experienced that the anchorage extractor as described in the present invention can develop sufficient strength to remove multiple anchorages as the one used for big size capitals. The multiple anchorage is a L-shaped structure having multiple holes, each hole adapted to receive an individual anchorage. A large force is required to remove the multiple anchorages, indeed, when the individual anchorages are positioned in the ground at different angles, the force required to remove them all at the same time is greater. Also, the anchorages for capitals are often inserted in grounds that are very compact, such as rocky grounds, asphalt, etc. . . .
[0021] The anchorage extractor can be made of metal or polymer having sufficient rigidity to withstand the forces transmitted during the extraction of anchorages. Aluminum, for example, is a good choice because it offers strength and lightness.
[0022] The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other objects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:
[0024] FIG. 1 is a perspective view of the anchorage extractor.
[0025] FIG. 2 a is a perspective view of the anchorage extractor.
[0026] FIG. 2 b is an enlarged view of a portion of FIG. 2 a.
[0027] FIG. 3 is a top view of the safety mechanism of the anchorage extractor.
[0028] FIG. 3 b is a perspective view of the safety mechanism of the anchorage extractor.
[0029] FIG. 3 c is a perspective view of the position selector.
[0030] FIG. 4 is a schematic sectional view of the main body.
[0031] FIG. 5 is a perspective view of the lifting mechanism and of the release mechanism of the anchorage extractor.
[0032] FIG. 6 is a sectional view of the anchorage extractor.
[0033] FIG. 7 is an exploded view of a portion of the anchorage extractor.
[0034] FIG. 8 is a perspective close-up view of the angle selector mechanism.
[0035] FIG. 9 a is an exploded view of the angle selector mechanism.
[0036] FIG. 9 b is a cross-section view of the angle selector mechanism of FIG. 9 a.
[0037] FIG. 10 is a schematic cross-section of the main body.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] A novel anchorage extractor will be described hereinafter. Although the invention is described in terms of specific illustrative embodiment(s), it is to be understood that the embodiment(s) described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.
[0039] As shown in FIG. 1 , the anchorage extractor includes a first lever 104 , a main body 102 and a base 188 . The base 188 is formed, in this embodiment, by a first and a second section 190 and 191 which are arranged in a “V” shape or triangular shape one relative to another. These two sections 190 and 191 are connected by a third section 192 on which are fixed wheels 195 . Two pivoting members 193 and 194 are connected to the base and the main body 102 , the first extremity pivotally connected to the sliding structure and the second extremity connected to the base. The connections between members 193 and 194 with the base 188 and the main body 102 are of the pivot type, to change the angular position of the main body 102 relatively to the base 188 . The shape of the base 188 includes an enlarged portion (section 192 ) which provides a stable support surface when the anchorage extractor is in use. It should be noted that the base may have a shape other than triangular, the important aspect being to have a support surface sufficiently large and stable.
[0040] To minimize the space occupied when the anchorage extractor is not used, it can preferably be folded on itself or disassembled. As illustrated in FIG. 1 , the main body 102 , the base 188 and the pivoting members 193 and 194 are fixed to each other by using pivot connections 202 , 204 , 206 and 208 . By dismantling one or more of these connections it is possible to fold or disassemble the anchorage extractor. For example, if the pivot connection 202 or the pivoting members 193 and 194 are dismantled, the main body 102 can be disposed or folded on the base 188 . The pivot connections are typically composed of a rod with a bolt at each end to connect the main body 102 , the base 188 and the pivoting members 193 and 194 .
[0041] The main body 102 of the anchorage extractor 100 can be positioned in the same axis or almost the same as the longitudinal axis of the anchorage or stake to remove. A first embodiment of the mechanism for changing the angle of the main body is illustrated in FIGS. 2 a, 2 b , 3 a , 3 b and 3 c . It includes a sliding structure 122 , an angle selector 120 , a transmission member 121 , a locking rod or member 127 , a guiding member 123 , positioning plates 124 and a security device 126 . The angular position selector 120 is connected to the transmission member 121 which is itself connected to a locking member 127 . The sliding structure includes a hole 125 which is adapted to receive the guiding member 123 . The plates 124 extend on both sides of the main body 102 . The transmission member 121 is partially contained in the sliding structure 122 . The security device 126 , in a locked position, is partially inserted into the transmission member 121 , preventing the angle of the anchorage extractor to change during its use.
[0042] To change the angle of the main body 102 , the security device 119 is held in unlocked position and the angle selector 120 is activated. When the angle selector 120 is activated, it releases the locking member 127 and the sliding structure 122 is displaced along the main body 102 . The positioning plates 124 maintain the lateral position of the sliding structure 122 . When the angular position of the main body 102 is reached, the angle selector 120 is released and the locking member 127 is repositioned to its locked position, i.e. in one of the holes designed to receive the locking member 127 . The surface 128 of main body 102 , adjacent to the locking member 127 , comprises the positioning holes 129 . Each of these positioning holes 129 correspond to an angular position of the main body 102 . The number of positioning holes 129 determines the number of possible angular positions of the main body 102 .
[0043] As shown in FIGS. 4 , 5 and 6 , the main body 102 comprises a longitudinal cavity 118 and an opening 116 where the drive wheel 144 interacts with the rack 140 . A rack 140 and a plate 160 , which are fixed to each other, are located in the cavity 118 . In FIG. 10 , is it shown that the rack 140 is connected to the rack support structure 161 . The rack support structure 161 slide on the low-friction material block 221 .
[0044] FIG. 7 shows the driving mechanism, which includes a first gear or drive wheel 144 , a first lever 104 , the rack 140 , a second gear (or sprocket) 142 , and a shaft 156 . The sprocket 142 and the drive wheel 144 are connected to the shaft 156 . The mounting blocks 180 and 182 are mounted on the shaft 156 . The rotating block 154 comprises a hole 155 that is adapted to receive the shaft 156 . The shaft 156 rotates in the hole 155 . The first lever 104 is connected to the rotating block 154 . A first lever-lock 146 , controlled by the second lever or handle 148 , is connected to the rotating block 154 .
[0045] Attachment means or connector such as a hook 170 and/or a jaw 172 , to which one or more anchorages are attached, is attached to the plate 160 , shown in FIGS. 4 and 6 . When the drive mechanism is actuated, by displacing upwardly and downwardly the first lever 104 , the rack 140 is driven upward and thereby removes the anchorage from the ground.
[0046] To displace the rack 140 , the first lever 104 is moved up and down. By lowering the first lever 104 , the first lever-lock 146 contacts one of the teeth of the drive wheel 144 and the latter rotates along the shaft 156 . The rotation of the drive wheel 144 causes the shaft 156 to rotate and this rotation is transmitted to the sprocket 142 . The sprocket 142 is engaged with the rack 140 and drives the latter upward. The reduction ratio depends on the diameters of the drive wheel 144 and of the sprocket 142 . In a preferred embodiment, the drive wheel 144 comprises less teeth than the sprocket 144 .
[0047] The handle 148 of the first lever-lock 146 is automatically held in a locked position using a spring (not shown in the figures). The second lever-lock 150 is adapted to interact with the teeth of the drive wheel 144 , it locks the drive wheel 144 , and consequently the rack 140 , to its current position and the first lever 104 may be raised again to transmit a further displacement to the rack 140 . When the anchorage is removed from the ground, the release mechanism 151 allows the rack 140 to be repositioned to the starting position. The release mechanism 151 comprises the release lever 152 and the second lever-lock 150 . By actuating the release lever 152 , the second lever-lock 150 is disengaged from the drive wheel 144 and allows the latter to rotate freely and allow the rack 140 to go back to its rest or starting position.
[0048] To reduce the friction occurring between the plate 160 and the main body, strips or block 220 of a material having a very low coefficient of friction are connected to the main body or on the plate. This material may be, for example, UHMWPE.
[0049] To remove an anchorage from the ground, the user positions the extractor near the anchorage to be removed. The user adjusts the angle of the main body 102 to place it substantially parallel to the angle of the anchorage. The anchorage is connected to the extractor through the hook 170 or the jaw 172 , or any other suitable means, depending on the physical configuration of the anchorage. It is possible to use an intermediary such as a chain to attach the anchorage to the hook 170 or the jaw 172 .
[0050] At the starting or rest position, the rack 140 is ideally located at its lowest position relatively to the main body 102 . The user moves the first lever 104 upwardly, this movement does not offer resistance, and then moves the first lever 104 downwardly, this movements driving the drive wheel 144 and moving upwardly the rack 140 within the cavity of the main body. Under the action of the sprocket on the rack, the rack slide upwardly
[0051] To reposition the extractor to the starting position, the user actuates the release lever 152 , allowing the rack 140 to move down freely.
[0052] FIGS. 8 and 9 shows another embodiment of an angle selector for the main body. It comprises a sliding structure 222 , an angle selector 220 , a locking member 227 , positioning plates 224 and a spring 228 . The angle selector 220 is connected to the locking member 227 . The sliding structure 222 comprises a hole 225 which is adapted to receive the guiding member 223 . The plates 224 extend on both sides of the main body 102 . The locking member 227 is partially contained in the sliding structure 222 . The spring 228 is contained in a hole in the sliding structure 222 (shown at the exterior of the sliding structure in FIG. 9 ). The extremity of the locking member 227 is adapted to be received by one of the holes 229 in the guiding member 223 . To change the angle of the main body, a user pulls the position selector 220 , it will compress the spring 228 , and displaces the sliding structure 222 upwardly or downwardly. The user let go the angle selector 220 when the main body is at the appropriate angle and the spring will force the locking member 227 to move towards the guiding member 223 . When the locking member 227 faces one of the positioning holes 229 , the extremity of the locking member 227 engages with the hole and locks the main body at the selected position or angle. It is to be noted that the sliding structure may be made in one block or more, depending of the design.
[0053] While illustrative and presently preferred embodiment(s) of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
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The present invention is directed to an anchorage extractor. The extractor is used to remove post, anchorage or stake from the ground without using a force generated by a motor. The anchorage extractor comprises a base disposed on the ground to provide a stable support. A lever is connected to a driving wheel that is connected to a rack. The anchorage is attached to the rack and when the lever is actuated, the drive wheel drives the rack upward, removing the anchorage from the ground. An advantage of the present invention is that the direction of the extraction force is parallel to the anchorage axis by adjusting the angle of the extractor. The extractor may be folded on itself or dismantled to be transported.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for removing noise in still and moving pictures, and the invention can be used in any still or moving picture compression or coding algorithm where the reconstructed picture suffers from block distortion noise commonly known as blocky noise. This method selectively filters the image such that the picture is restored and the blocky noise as well as ring and mosquito noise are removed.
2. Description of the Related Art
Many algorithms and standards exist for compression of still and moving pictures. These include standards such as the ITU-T H.261 and H.263, and the ISO standards for JPEG, MPEG-1 and MPEG-2. More recently, work has begun on the MPEG-4 video coding standard. All of the algorithms mentioned use the transform coding technique, in particular the Discrete Cosine Transform, DCT. In this technique the picture is first partitioned into small blocks of 8 pixels high and 8 pixels wide. These blocks of pixels are then transformed into the DCT domain where the transform coefficients are subjected to quantization to reduce the amount of information. At high compression ratios, most of these coefficients are quantized to zero. The quantization noise introduced during this process results in visual artifacts when the blocks of coefficients are transformed back into the pixel domain.
This artifact is a result of loss in the high frequency components of the transform coefficients. Since these coefficients are reduced to zero, the inverse quantization process cannot faithfully reproduce the original signal. The result is that the pixels at the edge of two adjacent DCT blocks have very different values. This difference in values makes the picture appear to be made up of blocks. This visual artifact is known as a blocky noise artifact. FIGS. 1A and 1B graphically depict how the blocky noise is created by coarse quantization.
FIG. 1A shows original pixel values in which pixels P 0 , P 1 , P 2 , P 3 , P 4 , P 5 , P 6 and P 7 have gradually increasing values. Note that a line between pixels P 3 and P 4 represent a boundary between the blocks for the DCT processing. Thus, the pixels P 0 , P 1 , P 2 , and P 3 are processed in one DCT block, and pixels P 4 , P 5 , P 6 and P 7 are processed in the next neighboring DCT block. After DCT processing, the DCT coefficients are quantized. During the quantization, some data are lost. Then, after inverse DCT processing, the pixels P 0 , P 1 , P 2 , and P 3 in the one DCT block will take different values from their original values, as shown in FIG. 1 B. Similarly, the pixels P 4 , P 5 , P 6 and P 7 in the neighboring DCT block will take different values from their original values. In FIG. 1B, arrows added to the points representing the pixel values show the changes between before and after the DCT processing, quantization processing, and inverse DCT processing. After the inverse DCT processing, as shown in FIG. 1B, there will be a step between the pixel values P 3 and P 4 , resulting in a loss of a gradual change of the pixel value at the boundary between the blocks for the DCT processing. Thus, the reproduced image will be a mosaic effect added picture.
FIGS. 2A and 2B show how the loss of high frequency coefficients in the DCT domain results in ring and mosquito noise artifacts. Note that in FIG. 2A, a dotted line between pixels P 2 and P 3 represent a discontinuity of the picture, such as an edge line of a door in the picture. After the DCT processing, quantization processing, and inverse DCT processing, the pixel values P 2 and P 3 will be further separated, as shown in FIG. 2B, resulting in a so-called, ring and mosquito noise providing undesirably emphasized edge lines in the picture.
The main problem to be solved is how to devise a general algorithm that can be applied to the picture with the artifact such that the blocky noise as well as ring and mosquito noise are reduced or removed. The goal is to manipulate the picture in such a way that the recovered picture is visually as close to the original picture as possible.
The second problem to be solved is how to prevent the blocky noise as well as ring and mosquito noise from propagating to the next frame in a sequence of moving pictures where motion compensation is used.
SUMMARY OF THE INVENTION
In order to solve the above problem, an integrated filtering technique is used. There are many filtering techniques currently being used for removing noise from pictures. What is novel about this invention is the method of adaptively deciding the pixels that are filtered and those that are not filtered as well as the values that are adaptively reset and used in the non-linear filter depending on the decisions.
To solve the propagation problem, the filter is placed within the motion compensation loop prior to the frame store so that the filtered picture is used in the motion compensation instead of the picture with artifacts. Though it is common to use a filter in the prediction loop to improve the motion compensation performance, the novelty of this invention is the use of this particular deblocking filter in the prediction loop to prevent the propagation of blocky artifacts. In prior art such as the H.261, the loop filter serves no other purpose except for improving the motion compensation prediction. In this invention the filter is not intended for the improvement of the motion compensation performance but rather for the simultaneous task of removing the blocky artifact in the current picture and also for preventing the propagation of blocky artifact into the next picture.
The current invention operates on the reconstructed still picture that is decoded from the compressed bitstream, as shown in FIG. 3 . In the case of moving pictures it can operate outside the prediction loop as a post filter, shown in FIG. 4, or within the prediction loop as a loop filter, shown in FIG. 5 . In all these cases the filter used is the same. It operates on the boundary of the blocks where blocky noise manifests.
The blocky noise removal filter is a separable filter and can be applied in the horizontal and vertical directions in tandem. The filter used is a modified version of the bi-linear interpolation filter. Two values of the end points are determined from the pixels on either side of the block boundary. The filtered values on either side of the filter represent the bi-linearly interpolated values of the two endpoints modified by a scaled value determined from the deviation of the actual pixel from the end points.
The ring and mosquito noise filter can be in one of two forms. The first is a block based filter where a window of pixel is conditionally averaged to remove isolated noise. This two dimensional filter can also be implemented in one dimension along the horizontal or vertical direction where the window is only one dimension along the direction of the filtering. This filter also removes the noise by conditionally averaging the pixel around the center of the window.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a diagram showing pixel values before the blocky noise is created.
FIG. 1B is a diagram showing pixel values after the blocky noise is created.
FIG. 2A is a diagram showing pixel values before the ring and mosquito noise is created.
FIG. 2B is a diagram showing pixel values after the ring and mosquito noise is created.
FIG. 3 is a block diagram of the encoder, decoder and filter according to the present invention.
FIG. 4 is a block diagram showing a detail of the encoder and decoder and the position of the filter as a post filter in a moving picture coding scheme.
FIG. 5 is a block diagram showing a detail of the encoder and decoder and the position of the filter as a loop filter in a moving picture coding scheme.
FIG. 6 is a flow chart showing an operation of the filter for removing the block noise.
FIG. 7 is a diagram showing positions of the pixels to be processed.
FIG. 8 is a diagram showing pixel values after the blocky noise is created.
FIG. 9 is a diagram showing pixel values after the filtering is applied according to the present invention to eliminate the blocky noise.
FIG. 10 is a flow chart showing an operation of the filter for removing the blocky noise and ring and mosquito noise.
FIG. 11 are diagrams showing pixel values after the ring and mosquito noise is created and after the same is removed.
FIGS. 12A, 12 B, 12 C, 12 D, 12 E, 12 F, 12 G, 12 H, 12 I and 12 J are block diagrams showing various possible locations of the filter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 3, a block diagram of an encoder, a decoder and a filter 7 , according to the present invention is shown, for a still picture. The encoder includes a block based discrete cosine transform 1 , a quantizer 2 and a variable length coding unit 3 . The decoder includes a variable length decoder 4 , an inverse quantizer 5 and an inverse discrete transformer 6 .
Referring to FIG. 4, a block diagram of an encoder, a decoder and a filter 23 , according to the present invention is shown, for a moving picture. The encoder includes a block based discrete cosine transform 11 , a quantizer 12 , a variable length coding unit 13 , an inverse quantizer 14 , an inverse discrete transfer 15 , a frame memory 16 for storing previous reconstructed picture, and a motion compensation module 17 . The decoder includes a variable length decoder 18 , an inverse quantizer 19 , an inverse discrete transformer 20 , a frame memory 21 for storing previous reconstructed picture, and a motion compensation module 22 .
Referring to FIG. 5, a block diagram similar to that shown in FIG. 4 is shown. In FIG. 4, filter 23 , according to the present invention, is connected to the output of the decoder, but in FIG. 5, two filters 23 A and 23 B are provided instead. Filter 23 A is provided in the encoder between an adder and the frame memory 16 . Filter 23 B is provided in the decoder between an adder and the frame memory 21 .
The filter 7 , 23 , 23 A or 23 B, according to the first embodiment of the present invention, serves as a blocky noise filter. The function and operation of the block noise filter of the first embodiment is described below in connection with FIGS. 6, 7 , 8 and 9 .
The filter 7 , 23 , 23 A or 23 B, according to the second embodiment of the present invention, serves as a blocky noise and ring and mosquito noise filter. The function and operation of the block noise and ring and mosquito noise filter of the second embodiment is described below in connection with FIGS. 10, 11 and 12 A- 12 J.
Referring to FIG. 6, a flow chart of the block noise filter is shown. In FIG. 6, steps 51 to 61 are for processing pixels in vertical direction and steps 62 to 72 are for processing pixels in horizontal direction. Since the vertical direction processing and the horizontal direction processing are substantially the same, the description below is directed to the steps 62 to 72 for the horizontal direction, and the description for the vertical direction processing through steps 51 to 61 is omitted.
At step 62 , a horizontal line scan starts.
At step 63 , one block boundary is located, such as shown in FIG. 7 . One block includes 64 (=8×8) pixels, and the block boundary between two blocks aligned side-by-side horizontally. As shown in FIG. 7, eight horizontal consecutive pixels P 0 , P 1 , P 2 , P 3 , P 4 , P 5 , P 6 and P 7 are taken into consideration, of which four consecutive pixels P 0 , P 1 , P 2 and P 3 (referred to as group 1 ) extend horizontally from the boundary line into the left side block and four consecutive pixels P 4 , P 5 , P 6 and P 7 (referred to as group 2 ) extend horizontally from the boundary line into the right side block. There will be eight pairs of group 1 and group 2 along one block boundary.
At step 64 , The mean values, m 1 and m 2 , of the pixels in group 1 and group 2 , respectively, are obtained, according to equations (1) and (2), respectively. m 1 = 1 4 ∑ i = 0 3 P i , and ( 1 ) m 2 = 1 4 ∑ i = 4 7 P i . ( 2 )
At step 65 , the amplitude of the difference between these mean values is compared with a predetermined threshold T 1 to decide if the pixels are to be filtered. If the value is greater than or equal to the threshold T 1 , then a natural edge (a picture discontinuity such as a door edge line) has been detected and no filtering is done and the process proceed to step 72 . If the value is less than the threshold T 1 then the process proceeds to step 66 .
At step 66 , two values, c 1 and c 2 , equivalent to the sum of the difference between each pixel in groups 1 and 2 and its corresponding mean value m 1 and m 2 , on either side of the boundary, are calculated. The mathematical equations (3) and (4) are shown below. c 1 = ∑ i = 0 3 P i - m 1 , and ( 3 ) c 2 = ∑ i = 4 7 P i - m 2 . ( 4 )
At step 67 , these values are compared with a second threshold T 2 . If the value c 1 is greater or equal to a second threshold, T 2 , then the corresponding group of pixels are not filtered and the value m 1 is reset to P 3 , the value of the pixel on the corresponding side closest to the boundary. Similarly, if the value c 2 is greater or equal to a second threshold, T 2 , then the corresponding group of pixels are not filtered and the value m 2 is reset to P 4 , the value of the pixel on the corresponding side closest to the boundary.
If (c 1 ≧T 2 ) then m 1 =P 3 , and (5)
If (c 2 ≧T 2 ) then m 2 =P 4 (6)
At step 68 , if c 1 is less than the second threshold T 2 , step 69 is carried out for filtering the pixels in group 1 according to equation (7).
Similarly, at step 68 if c 1 is less than the second threshold T 2 , step 71 is carried out for filtering the pixels in group 2 according to equation (8). P i ′ = ( 15 - 2 i ) P i + ( 2 i + 1 ) P 4 16 , i = 0 , 1 , … , 3 ( 7 ) P i ′ = ( 15 - 2 i ) P 3 + ( 2 i + 1 ) P i 16 , i = 4 , 5 , … , 7 ( 8 )
Before the filtering according to equations (7) and (8), the pixel values may be P 0 , P 1 , P 2 , P 3 , P 4 , P 5 , P 6 and P 7 as shown in FIG. 8 . But after the filtering according to equations (7) and (8), the pixel values may be changed to P′ 0 , P′ 1 , P′ 2 , P′ 3 , P′ 4 , P′ 5 , P′ 6 and P′ 7 as shown in FIG. 9 .
The above is carried out for eight pairs of groups 1 and 2 in one block boundary, and the same is carried out for the next block boundary.
By the blocky noise filtering, the mosaic appearance of the picture at the block boundaries can be eliminated.
Referring to FIG. 10, a flow chart of the block noise and ring and mosquito noise filter is shown. In FIG. 10, steps 151 to 160 are for processing pixels in vertical direction and steps 162 to 71 are for processing pixels in horizontal direction. Since the vertical direction processing and the horizontal direction processing are substantially the same, the description below is directed to the steps 162 to 171 for the horizontal direction, and the description for the vertical direction processing through steps 151 to 160 is omitted.
Steps 162 to 166 are the same as step 62 to 66 described above in connection with FIG. 6, and the description therefor is omitted.
At step 167 , values c 1 and c 2 are compared with a second threshold T 2 . If the value c 1 is greater or equal to a second threshold T 2 , and if the value c 2 is greater or equal to a second threshold, T 2 , the procedure advances to step 169 to carry out equations (9) and (10). In this case, the boundary line matches with the some edge line in the picture. Equations (9) and (10) are modified form of the above described equations (5) and (6).
If (c 1 ≧T 2 or c 1 ≧T 2 ) then P ~ i = P i - 1 + 2 P i + P i + 1 4 , i = 3 , 4 , and ( 9 ) P i =P i , i=0, 1, 2, 5, 6 and 7, (10)
If the value c 1 is less than the second threshold T 2 , and if the value c 2 is less than the second threshold, T 2 , the procedure advances to step 168 to carry out the above described equations (7) and (8). Step 168 for carrying out equations (7) and (8) and step 169 for carrying out equations (9) and (10) are for the blocky noise filtering.
At step 170 , ring and mosquito noise filtering is carried out to obtain filtered pixel values P i ′ using equation (11). In equation (11), δ()=1, if is true, and δ()=0 otherwise. P i ′ = P ~ i , i = 0 and 7 , and P i ′ = ∑ j = i - 1 i + 1 P ~ j · δ ( P ~ i - P ~ j < QP ) ∑ j = i - 1 i + 1 δ ( P ~ i - P ~ j < QP ) , i = 1 , 2 , 3 , … , 6 , ( 11 )
The effect of equation (11) is as follows. The values for the two pixels with index 0 and 7 are copied to P′. For the remaining six pixels, the filtered result, P i ′, are obtained by comparing the value of the neighboring pixel on either side of the current pixel, P i . As show by the example of FIG. 11, if the absolute difference between the current pixel and the neighboring pixel is below the quantization step size QP, then the neighboring pixel is added to the current pixel to give the sum. The average value of the sum is then obtained to give the filtered result. Pixel P 3 is not used for the calculation of pixels P′ 2 and P′ 4 because the absolute differences were larger than QP. Similarly, pixels P 2 and P 4 are not used in the calculation of pixel P′ 3 because the absolute differences were larger than QP.
The process then proceeds to step 171 which checks if all boundaries of the horizontal scan have been completed. If there are more boundaries in the current scan, the process is passed to step 163 , and otherwise the process completes.
FIGS. 12A, 12 B, 12 C and 12 D show block diagrams of various order combinations of horizontal deblocking filter 31 A (corresponding to steps 168 and 169 ), horizontal ring and mosquito noise filter 32 A (corresponding to step 170 ), vertical deblocking filter 31 B (corresponding to step 157 and 158 ), and vertical ring and mosquito noise filter 32 B (corresponding to step 159 ).
FIGS. 12E, 12 F, 12 G, 12 H, 12 I and 12 J show block diagrams of various order combinations of horizontal deblocking filter 31 A (corresponding to steps 168 and 169 ), block ring and mosquito noise filter 33 (corresponding to steps 159 and 170 ) and vertical deblocking filter 31 B (corresponding to step 157 and 158 ).
According to the present invention, the filter removes unwanted blocky noise as well as ring and mosquito noise. When the filter is placed into the loop it further reduces the blocky noise and mosquito noise. This is because the blocky noise is removed from the reference picture and therefore is not propagated into the next picture.
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A method for filtering a blocky noise, as well as ring and mosquito noise, from still and moving pictures is disclosed. The method has the steps for locating a block boundary in the picture and selecting pixels on one side of the block boundary as a first group and pixels on the other side of the block boundary as a second group, calculating mean values (m 1 , m 2 ) and deviation (c 1 , c 2 ) of the pixels in each of the first and second groups, detecting whether or not the deviations (c 1 , c 2 ) are smaller than a predetermined threshold value (T 2 ), applying a first predetermined filtering (equations (5), (6)) when the deviations (c 1 , c 2 ) are not smaller than a predetermined threshold value (T 2 ); and applying a second predetermined filtering (equations (7), (8)) when the deviations (c 1 , c 2 ) are smaller than a predetermined threshold value (T 2 ).
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BACKGROUND
[0001] A public key digital certificate is a token that typically includes at least the following properties: (1) a starting validity date and time; (2) a defined validity period of the token; (3) a unique identifier, typically a serial number and an issuer identifier; and (4) an associated revocation state. In other words, a certificate has information that identifies who issued it, what its serial number is, when it starts, and how long it lasts. These items of data do not change, and thus are static. The revocation state, however, can change from a valid state to a not valid state while the duration information would indicate the certificate is valid. The revocation state usually cannot be derived from the certificate itself. The most widely used certificate is a type defined in RFC-2459, and RFC-3280.
[0002] A typical current certificate management systems, known as a certificate authority (CA), uses database systems to store the information regarding each certificate and the certificate itself separately in a database. Typically, there is one database row per certificate containing the relevant data fields as database columns. Storage with these fields leads to a basic data complexity of N, where N denotes the number of certificates. Usually the CA system also maintains revocation information, often stored as a separate database with a column linked to particular database rows for the certificates.
SUMMARY
[0003] The systems and methods described here can provide a more efficient combination of a certificate authority and a validation service for exploring whether a particular certificate has been issued, a revocation state (RS) associated with a current certificate, and possibly a date associated with a revocation. The system described here provides such a validation service that can provide revocation data, and also provide an affirmative confirmation that a certificate is valid, with reduced data complexity, i.e., a reduced number of data items to be stored for a given number of certificates. The systems and methods described here can have a data complexity based on a number of significant time intervals per a given issuer identifier. This system can be used for very large numbers of certificates, e.g., more than 100,000 or even more than 1,000,000 or 10,000,000 certificates. The system can be used with standard CRL or OCSP protocols.
[0004] Other features and advantages will become apparent from the following detailed description, drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram illustrating a prior art system in which certificate data has been stored.
[0006] FIG. 2 is a block diagram illustrating an embodiment of a system and method of storing certificate information as described in the description.
DETAILED DESCRIPTION
[0007] FIG. 1 represents a known prior art system in which there is a typical known certificate authority (CA) 10 that issues new certificates and modifies a revocation state of those certificates. The certificate data is held in a certificate management system database 11 and includes the following fields: Serial Number (SerNo), Valid Not Before, Valid Not After, and Revocation State (RS). This data needs to be accessed frequently as transactions are taking place over the Internet. To help make this information available, the revocation data is replicated across a number of databases 12 . These databases 12 can be accessed by an online certificate status protocol (OCSP) 14 . An OCSP is an Internet protocol used for obtaining the revocation status of an X.509 digital certificate and is described in RFC 2560.
[0008] OCSP is one method for providing information to allow others to determine the revocation state of the certificate. An example of such a system is described in German application DE 100 61 102, which is incorporated herein by reference. OCSP is an alternative to another approach for identifying revoked certificates, known as a certificate revocation list (CRL). With OCSP, revocation state data can be accessed with less substantial data transfer than is typically required with CRL systems.
[0009] As indicated in FIG. 1 , there is a separate row of data for every certificate as identified by serial number. Such storage can be efficient and effective with thousands or even tens of thousands of certificates. However, certificates could be issued in large quantities for use in consumer devices, such as set top boxes, and in some places to individuals on a large scale. For example, Germany is implementing a health care system in which everyone will receive a health card, and each health card would have a digital certificate. Such systems could result in tens of millions of certificates being issued (60-80 million for health cards in Germany, for example), thereby creating very expensive database costs.
[0010] Referring to FIG. 2 , in this system, the replicated databases, and OSCP can be substantially similar to those in prior art FIG. 1 . A certificate authority 21 issues groups of certificates that share common duration information, e.g., the same start and end date of validity (“Valid Not Before” and “Valid Not After”), instead of setting these values different for each certificate and using consecutive serial or sequential numbers. The certificate management system database 20 also stores certificate information in a different manner from database 11 ( FIG. 1 ). The system includes applicable interfaces and hardware, such as general purpose programmed processors, specific purpose processors, or other logic for storing information, looking up data, retrieving data, and providing interfaces. Aspects of the system can be implemented in software with instructions stored on a computer readable medium, such as a disk, memory stick, or other memory that can store software.
[0011] In this system, there is a reduced complexity certificate management system database in which ranges of serial numbers (from SerNoLow to SerNoHigh) are grouped together based on common valid duration information, shown here as “Valid Not Before” (start) dates, and “Valid Not After” (end) dates that are stored persistently. A separate list sets out the serial numbers that have a revocation state that is something other than valid or “not revoked.”
[0012] For simplicity, it is assumed that the issuer identifier (IID), e.g., the certificate authority, is identical for all certificates in this section. If multiple IIDs are to be supported in the system, the database system (e.g., tables within a database or separate database) can be replicated for each IID. The certificate issuance system usually is assumed to write audit data regarding each issued certificate. Since the validation service does not need to access these data, this audit data is not considered relevant for the data complexity.
[0013] The data could be stored with other parameters or with the same parameters with different names. The duration information could be based on Valid Not Before and Validity Period fields, rather than Valid Not After. The storage does not need to be a database; the information could be stored in any suitable form of memory for storing the information.
[0014] Optionally, the serial number data for certificates can be encoded/encrypted. For example, for millions of health cards, each can have a coded number (which could include numerals or letters). This coded number would typically be provided in a machine readable format only, e.g., on a magnetic stripe, although it could possibly be printed on the card. This coded serial number would have no apparent relation to any other serial number unless it were decoded. For example, one could not tell that two certificates had consecutive serial numbers when the numbers are coded.
[0015] The following example illustrates a validation process, using a card with a certificate as an example, although other types of transactions would work similarly. When the card is presented for a transaction, e.g., a pharmaceutical purchase in case of a health card system, the coded serial number and issuer identifier are read by machine and provided to an issuer's validation system. The validation system receives the coded serial number and converts the coded serial number to an internal serial number, e.g., a sequential serial number. The system uses the serial number to look up in the database an entry matching the given issue identifier and where the requested serial number is contained in a range of serial numbers. For example, a serial number of 6001 might be represented in a row with serial numbers 5000-9999, which all have a common valid duration (e.g., stop and start date). It could be the case that all serial numbers in that range have been revoked. In that case, that answer (revoked) is returned by the system. In other cases, it could be that the serial number range of 5000-9999 is a valid (not revoked) range. In that case, the system checks a separate revocation list to see if the particular serial number (e.g., 6001) is on the revoked list. If yes, the answer returned is that the certificate is revoked, and if not, a valid answer is returned. The acts of checking the revocation list and the general serial number list could be done in either order.
[0016] One characteristic of this system is the ability to affirmatively determine that a certificate with a certain serial number is valid, i.e., if it is identified as being in a valid range and not one of the revoked certificates. The individual information associated with certificates could indicate other forms of “not valid” in addition to revoked, e.g., suspended.
[0017] In case a certificate revocation list (CRL) is to be generated, every certificate with a non-final revocation state different from the default revocation state (e.g., a not revoked default state) is identified by an appropriate entry in a database. This entry is deleted if the state is changed back to the default revocation state or if it is changed to a final revocation state. Every certificate with a final revocation state is identified by an entry in the database until it is included in a CRL the first time. Then it is identified by an entry in the CRL(s) only to keep the database small. The recommendation is to store entries representing a non-final revocation state at the end of the CRL preceded by the new final state entries, i.e., the ones that come from the temporary database entries and appear the first time in a CRL. Doing this, the application maintaining the CRL is not required to read-in the whole current CRL when generating the new one. It could simply start appending entries at the (file) location after the last final state entry remembered from generating the last CRL. CRL processing applications (e.g., validation systems) could also remember the offset of the last entry which has already been added to the internal memory. Only the remaining entries would have to be added. The Delta-CRL can be generated. Only (all) the entries with a non-final revocation state the new entries with non-default revocation state stored in the database have to be taken. In a system compliant to RFC2459 and RFC3280, a state transition from suspended to revoked will not change the RS date. This will most likely be a single entry per certificate as compared to a block. This list of revoked certificates may have different internal representations, e.g. sequential lists, hash-trees, or B-trees, although referred to as a CRL in this document.
[0018] One example that is mentioned here is a health card, but other applications can benefit from such a system, e.g., device certificates. In such an environment, millions of devices, such as set top boxes, can be equipped with certificates for transactions done over networks. The revocation processing time will likely not be critical.
[0019] It should be apparent that modifications can be made without departing from the scope of the invention as defined by appended claims. For example, as indicated previously, while the memory has been described in terms of a database, other forms of memory could be used because of the reduced need for data. While certain examples of certificates have been described, other certificates can be used and the data can be stored with fields that vary somewhat from those described above, although it would typically be required that some field indicate the time during which the certificate is valid and not revoked and some identifier for the certificate. The certificates have been described as being consecutively numbered; such consecutive numbering could be by ones, but could also be by twos or tens or some other regular periodic system. The data is described as being in “rows” but this terminology should be understood to include any method in which data is organized and where data can be associated with other data; whatever the means, what is desired is for a number of certificates to be able to be grouped, e.g., in a consecutive range, and associated with common valid duration information, allowing the memory to group certificates and not require an individual entry for every certificate. All certificates with common duration information can be stored in one row, but significant savings in storage can be obtained even if multiple groups of certificates, each with common valid duration information, are stored in several different rows.
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A system and method for generating and storing a large number of public key certificates that enables a revocation status to be determined while providing a smaller amount of storage than is typically required.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for the compensation of losses of a signal along a transmission path, especially an acoustical transmission path, that is between at least one transmission point and a reception point in a room, particularly within a vehicle's interior.
2. Description of the Related Art
A similar topic is discussed in the simultaneously filed report “Kommunikationsanlage fuer Insassen in einem Fahrzeug” (“Communications' equipment for occupants in a vehicle”), the disclosed matter of this report is included herein by reference. This report has DE file number 19938171.2.
In a vehicle, e.g. in an automobile, the communications between vehicle occupants is degraded because of ambient noise. On the one hand, communications between occupants will be influenced by their seating arrangement. In that case the quality of the communication is especially poor between people sitting in the front and the back of the vehicle due to the speech direction (signal spreading) and the therefrom resulting corresponding signal loss along the transmission path. On the other hand, the communications between the occupants will be affected, for example, by road or wind noise. For improvement of the communications in the interior of the vehicle, anti-noise systems are usually used that reduce all ambient noise, especially motor noise, road noise and fan noise. To this end such anti-noise systems have a microphone, for example near the head of the occupants, that serves to acquire the wide band noise signals. The signal indicating the rotational speed of the engine can serve as an indicator of the engine noise. A loudspeaker will produce a signal that is of opposite phase to the noise signal, a so called anti-noise signal. Such an anti noise system is described, for example, in the article by Garcia-Bonito et al.: “Generation of Zones of Quiet Using a Virtual Microphone Arrangement,” Journal Acoustical Society of America, 1, Jun. 1997, pages 3498 through 3516. A detriment to these systems is that spoken communication among the occupants between acoustically unfavorable positions in the vehicle is further substantially affected.
Additionally, modern vehicles provide a hands-free speaking device for radio telephones, that makes possible communications with a distant participants. With this device the reduction of the ambient noise, such as, for example, audio signals, road noise or fan noise, in the interior of the vehicle is also important for improved communications. Additionally compensated for by such hands-free speaking devices are acoustical and electrical echoes, which likewise substantially affect communications, that occur due to the particularly long signal delays of the telephone network. Echo cancellation is usually used for this. The use by other occupants of the vehicle of the hands-free speech feature is very restricted due to their acoustically disadvantageous position in the vehicle, since the microphone is especially oriented for the driver of the vehicle.
SUMMARY OF THE INVENTION
The invention begins with the problem of specifying a process for the compensation of signal losses over a transmission path, whereby a particularly low loss and echo free communication between participants in a room is made possible. In addition, an apparatus for the compensation of losses of a signal is provided that operates to avoid, as much as possible, a deterioration of the communication due to ambient noise and/or echoes.
The first identified problem is inventively solved by the process for compensation of signal losses over the transmission path between at least one sending and receiving location in a room, in that the transmission path of the signal is determined and at least one parameter of an associated transmission function will be ascertained from the transmission path, whereby the signal level for a given position in the transmission path will be controlled via the ascertained parameters.
The invention begins with the observation that an acoustical signal, especially a wide band speech signal, varies especially widely during its propagation in a room, especially in the interior of a vehicle. In addition, the propagation of the speech signal will be substantially affected by additional disturbance signals, such as road and wind noise, as well as through acoustical and electronic echoes caused by electrical systems. On one hand the different signal level losses over the acoustical path, as they occur in the spoken communications between occupants in the vehicle, should be compensated for. On the other hand, disturbance signals that affect the speech signal should be substantially reduced. Also to be taken into account is the transmission path between the sending and receiving point, particularly in the transmission direction. That means different levels of communication impairments occur depending upon the respective position in the room of the speaking (i.e. sending point) and listening persons (i.e. reception point). In order to avoid this as much as possible, the present process is so laid out that the losses of the signal level will be compensated differently for each arbitrary position or place in a room. Additionally, the disturbance signals operating on the signal will be avoided in the compensation of the level losses. To this end a parameter of the transmission function associated with the transmission path will preferably be ascertained and that parameter will be applied to the control of the signal level. The control of the signal level for a given position in the room, e.g. for the rear seat of the vehicle (i.e. receiving point) when the person in the front position is speaking (i.e. sending point), via the parameters of the transmission function associated with the transmission path, guarantees an especially good communications between all persons in the entire room.
Advantageously the transmission path will be determined as an acoustical path and/or an electrical path of the signals. Thereby the determination of the acoustical path comprises, for example, the determination of the sending point, receiving point, the type of signal transmitted between the sending point and receiving point, e.g. a speech signal or audio signal and/or the operating ambient noise of the operating transmission path, such as, e.g. acoustical echo signals, wind or road noise. Analogous thereto, by the determination of the electrical paths, the sending point and receiving point for example are determined. Additionally the operational disturbance signals of the electrical path, e.g. electrical echo signals generated by feedback, will be determined. Through the determination of the transmission path, it is guaranteed that the characteristic influences of the transmission path will be determined so that the signal level will be correspondingly controlled to compensate for these influences.
Advantageously the attenuation of the signal between the sending point and receiving point will be determined as a parameter. For example the attenuation of the signals over the entire transmission path will be determined, and therewith the difference of the signal levels between the sending point and the receiving point. Consequently, those parameters will determine, for example, that the communications between the front and the rear seats in the vehicle is especially strongly affected.
Purposefully the signal level will be amplified upon exceeding a maximum value of the attenuation of the signal level for a given position. In other words: the value of the attenuation, e.g. from receiving point (i.e. listener in the rear seat or row of the vehicle), exhibits a positive value—it really exists as an attenuation of the signals along the transmission path—then the signal to be transmitted will be amplified by an amount corresponding to the amount that attenuation. This means, for example, in the case of communications between persons in a vehicle, that the speech signal to be transmitted between persons sitting in front of and behind each other will be amplified by a larger amount than for persons sitting next to each other since there would be less attenuation between them. Especially for persons sitting in front and behind each other, the amount of amplification of the speech signals will depend upon the actively speaking person. This means that an especially large amplification of the signal results when the person in front is speaking to the person in back.
In the case of an addition of several sound components of the signal along the transmission path an especially natural and easy communication is made possible by, in the case of not exceeding a minimum value of the attenuation, attenuating the signal level for a given position. For example, in a transmission of the signal of the speaking person there can be an overlay of signals on both the acoustical and the electrical path, whereby feedback occurs, that can be particularly reliably avoided through attenuation of the corresponding signal levels.
The amplification or attenuation of the signal level as a result of a threshold value—a maximum and minimum value of attenuation—makes possible an especially simple and fast adjustment of the signal level. Through such a setting of threshold values for the amplification or attenuation it is made possible to assign different transmission paths and their underlying transmission function and associated attenuation values.
Further, the propagation time of the signals between the sending point and the receiving point will be determined as a parameter. Thereby the determination of the parameters can be carried out through reverting to a singular or periodically determined parameter for the propagation time. Especially the propagation time of the signals along the acoustical path, i.e. the propagation time of the signals along the natural sound path, will be taken into consideration.
Preferably in particular the signal along the electrical path will be temporally delayed depending upon the propagation time of the acoustical signal. This makes possible in a simple manner the transmission of the signal containing the same information at the same speed along the acoustical path as well as along the electrical path.
Preferably additional parameters will be determined that represent the acoustic and/or electrical echoes between the sending point and the receiving point. The corresponding signal level for a given point can be controlled via these parameters in dependence upon the ascertained acoustical and or electrical echoes. Preferably a further parameter will be chosen to represent the disturbance or interference signal between the sending point and the receiving point. For example a noise signal, especially a road noise signal or a wind noise signal will be determined as a disturbance signal. In both cases—echoes and/or disturbance signals—the signal level will be correspondingly controlled according by the above described parameters according to the process in dependence upon the signal type and signal intensity.
According to the size and type of the room, e.g. vehicle interior or conference room, more than one parameter will be ascertained for the control of the signal level at a given place. Purposely the values of one or more parameter for at least one predetermined transmission path are stored and will be utilized for the control of the signal level. Especially for diagnoses or analytical purposes an image of the transmissions path in the room can be constructed from the stored values that describe the signal loss at a given point in the transmissions path. The values of the parameters are preferably stored in an attenuation matrix, wherein the specific parameters are assigned to each transmission path. Consequently the complex correlation between the parameters that represent the transmission function associated with the transmission path is described in an especially simple manner. Additionally, the process is accelerated with respect to the processing of the signal.
The second identified problem is inventively solved by a device for the compensation of signal loss along the transmission path through a controller for the determination of the transmission path as well as for the determination of at least one parameter of an associated transmission function, wherein the controller is combined with at least one level meter which, in combination with at least one echo canceller, is arranged between the sending point and receiving point for the control of the signal level at a given position in the transmission path. Preferably at least one microphone serves as a transmitter at the sending point. Alternatively a microphone array can be used in place of a microphone. At the receiving point at least one loudspeaker serves the purpose of a receiver. According to the type and size of the room, further loudspeakers can also be provided. According to the room size several sending and receiving points can be combined through one or more associated loudspeaker-microphone systems.
In the preferred embodiment at least one loudspeaker-microphone system is provided for every person and position in the vehicle. The level meter serves thereby for the control of the related and/or neighboring loudspeaker-microphone system(s). For example the microphone with the highest level will be identified as the active microphone. The loudspeaker that is near the active microphone will be deactivated or strongly attenuated via the level meter. The loudspeaker of the neighboring loudspeaker-microphone system will, on the other hand, be activated, i.e. the signal originating from the active microphone will be transmitted to the neighboring loudspeaker by means of the electrical path.
A preferably controllable attenuation device is provided between the loudspeaker and the microphone for the amplification or attenuation of the signal level. The signal level for the given position is correspondingly controlled through this in dependence upon the ascertained transmission path. Consequently the transmission path characteristically variable acoustical signal level will be compensated through corresponding amplification and/or attenuation. This makes possible, in a particularly simple manner, essentially improved communication between the persons for also acoustically adverse positions.
Thereby the natural sound (acoustic signal component) will only be reinforced through the amplified sound (electrical signal component) in so far that through the addition of both signal components for the given position an especially natural and carefree communication is made possible.
According to a further advantageous embodiment a preferably adjustable timing element is provided between the sending position and the receiving position. In order to adjust the variable propagation times of the signal over the acoustical and electrical path, the signal over the electrical path will be retarded in time in dependence upon the acoustical transmission time. Consequently it is ensured that both of the signal components for a given position will be overlaid. In particular, the transmission time of the acoustical signal component will be preferably determined on the basis of the previously ascertained values.
In order to avoid acoustical and/or electrical echoes, the echo canceller is preferably realized as a digital filter, especially an FIR-filter. Such a digital frequency filter will thereby be used in combination with the level meter. Through the combination of the echo canceller with the level meter, on the one hand, an echo free communication is possible, and, on the other hand, signal losses are reliably prevented.
The advantages obtained with the invention consist especially in that through the control of the signal level for a preferred position in the transmission path through means of the parameter(s) that describe the transmission function of the signal, an impairment of the communications through ambient noise and/or echoes is reliably prevented. This is made possible in particular through the combination of a level meter and echo canceller.
BRIEF DESCRIPTION OF THE DRAWINGS
Example embodiments of the invention are further explained by means of drawings. The drawings show:
FIG. 1 schematic of a communications installation for a room, in particular for a vehicle interior, with a plurality of sending and receiving positions,
FIG. 2 schematic of the communications installation with acoustical signal paths extending therein,
FIG. 3 schematic of the electrical circuit of the communications installation, and
FIG. 4 a table with values for parameters of different transmission paths.
DETAILED DESCRIPTION OF THE INVENTION
Identical parts are marked in all figures with identical reference numbers.
In FIG. 1 a vehicle interior 1 is illustrated as a room with a communication installation 2 with four positions P 1 through P 4 , wherein each comprise at least one receiving point 4 and at least one sending point 6 . There can also be fewer or more positions P 1 through P 4 according to the size of the vehicle interior 1 . In vehicle interior 1 at least one microphone M 1 through M 4 is provided as a transmitter at each sending point 6 . For example a microphone array that comprises a plurality of microphones can also be used in place of the microphones M 1 though M 4 . Similarly at least one loudspeaker L 1 through L 4 is provided at each receiving point 4 . According to the type of embodiment several loudspeakers L 1 through L 4 can also be provided. Consequently each position P 1 through P 4 is denoted by a so-called loudspeaker-microphone system.
FIG. 2 shows the four positions P 1 through P 4 with each of the associated loudspeaker L 1 through L 4 and with each of the associated microphones M 1 through M 4 . The positions P 1 and P 3 are occupied by persons, wherein the person in position P 3 is actively speaking and the person in position P 1 is listening. In operation of the communications installation 2 a transfer of the transmitted speech signal S occurs over at least one acoustical path A 1 through A 2 . That means that the signal S arrives at the person in position P 1 directly from the person in position P 3 by traveling over the acoustical path A 1 . Simultaneously the signal S from the microphone M 3 associated with position P 3 will be output on loudspeaker L 1 of the position P 1 . The person in position P 1 hears, as a result, the sum of the direct sound from acoustical path A 1 and the indirect sound from acoustical path A 2 of the signal S.
In addition to the direct input of the signal S, microphone M 3 receives the indirect sound from loudspeaker L 1 over a feedback path R 1 . In addition, signal S′ received via microphone M 1 will be output on loudspeaker L 3 , where it arrives at microphones M 1 and M 3 over further feedback paths R 2 and R 3 . Consequently several feedback couplings develop by the operation of the communications installation 2 , that can lead to an instability of the communications installation and that can especially lead to loud feedback whistles.
For the avoidance of such acoustical and/or electrical echoes as well as for the compensation of level losses of the signal S along the acoustical path A 1 , the communications installation comprises two electrical paths E 1 and E 2 for the signal S, as is shown in FIG. 3 . The electrical path E 1 runs between the microphone M 3 and the loudspeaker L 1 and comprise a level meter W 1 and an echo canceller K 1 . That means that the signal S picked up by microphone M 3 will be output on the loudspeaker L 1 over the electrical path E 1 . The echo canceller K 1 serves as the compensation for the acoustical and/or electrical echoes on loudspeaker L 1 . The echo canceller K 1 is thereby connected adaptively to level meter W 1 .
A summing element 8 is subsequently connected to the microphone M 3 which is fed with a signal S K from the echo canceller K 1 with a sign inversion. The signal S K represents thereby the value of signal S that is fed back from loudspeaker L 1 into microphone M 3 .
Additionally the electrical path E 1 comprises an attenuation element 10 and a time delay element 12 . The signal level is controlled via the attenuation element 10 , e.g. amplified, in dependence upon the amount of the attenuation exhibited by signal S along the transmission path, in particular along the acoustical path A 1 according to FIG. 2 . The delay element 12 , that is preferably tunable, serves to delay the signal S along the electrical path E 1 , whereby the delay is adjustable so that the signal S that is transferred along both the electrical path E 1 and the acoustical path A 1 simultaneously arrives at the position P 1 . Directly prior to the loudspeaker of position P 1 , the time delayed and amplified/attenuated signal S will be branched off into the echo canceller K 1 .
Similarly to the electrical path E 1 , the electrical path E 2 likewise comprises an additional level meter W 2 that is connected in combination with another echo canceller K 2 as well as another summing element 8 ′, another, in particular adjustable, attenuation element 10 ′ and another, in particular adjustable, time delay element 12 ′.
In addition the communications installation 2 comprises a controller 14 that, for example, is centrally arranged in the interior of the vehicle. The controller 14 comprises a number of inputs E 1 through En, through which the signal S′ of each microphone M 1 through M 4 is routed. Further a number of outputs O 1 through O n are provided that serve as the control for the level meter W 1 through W 2 .
Similarly to the communications installation 2 in FIG. 2 , the positions P 1 and P 3 are occupied, whereby the person in position P 3 actively speaks and the person in position P 1 listens. By the transmission of signal S along the acoustical path A 1 according to FIG. 2 , the signal S will affected be the loss and/or affect of the signal level through attenuation, disturbance signals, such as road or wind noise and will be leveled out and compensated via the communications installation 2 as described below:
The active microphone M 3 is determined by the controller 14 as being the microphone with the highest signal level. The loudspeaker L 3 arranged near to the active microphone M 3 is deactivated through the associated level meter W 2 via the associated output signal on output O 2 of the controller 14 , so that feedback from the loudspeaker L 3 into the microphone M 3 is certainly avoided. Alternatively the signal level is correspondingly heavily attenuated via the associated attenuation element 10 ′, so that a feedback from loudspeaker L 3 into the microphone M 1 and/or M 3 is likely not to occur.
In order to reinforce the signal S on the acoustical path A 1 on loudspeaker L 1 according to FIG. 2 the signal S on the electrical path E 1 will be directly transferred to the loudspeaker L 1 via the actively switched signal level W 1 . The signal level along the electrical path E 1 will thereby be driven in dependence upon at least one of the parameters of the associated transmission function. For the equalization of the level losses a parameter will be ascertained, that represents the attenuation of the signal S between position P 1 and the position P 3 . Preferably the attenuation of the signal S along the acoustical path A 1 between the position P 3 and the position P 1 will be determined with the aid of a desired level. The signal level will be amplified corresponding to the desired level via the attenuation element 10 . In other words, the loss in signal S along the acoustical path A 1 will be compensated for by the controlled attenuation element 10 in electrical path E 1 . The desired level of attenuation of signal S along the acoustical path A 1 in a standard automobile is, for example, approximately 12 dB. According to the type and design of the communications installation 2 , the signal level can be so controlled by means of a default or a variably adjustable desired level for the affected transmission path via the attenuation element 10 , that the desired level is reached. For example, upon exceeding a maximum value (i.e. maximum available attenuation) or by undershooting a minimum value (i.e. overlaying of several sound components) the signal level will, respectively, be proportionately amplified or attenuated.
Therein the acoustical (i.e. natural sound) and the electrical (i.e. amplified sound) sound components of the signal S arrive simultaneously at loudspeaker L 1 , the amplified signal in the electrical path E 1 is delayed via the delay element 12 . The time delay of the delay element 12 is thereby so chosen as to represent the propagation time of the signal along the acoustical path A 1 . Consequently there comes an addition of the two sound components—electrical and acoustical—at loudspeaker L 1 . The amplified and time delayed signal S will be fed directly from the loudspeaker L 1 to the echo canceller E 1 . The echo canceller E 1 comprises a digital filter, particularly an FIR-filter, for the compensation of the acoustical and/or electrical echoes. The signal Sk of the echo canceller E 1 will be fed into the summing element 8 with a sign inversion for the cancellation of the acoustical and or electrical echoes in the signal S. In addition, the echo canceller can insert another delay element, which is not illustrated, with a propagation time equaling that of the feedback path R 1 or R 2 from loudspeaker L 1 and L 3 to microphone M 3 and M 1 , respectively.
For an especially simple and fast compensation of the losses of signal S, each of the parameters that describe the associated transmission path, for example the attenuation and the propagation time, are inserted into an attenuation matrix according to Table 1 in FIG. 4 . Therein the columns and the rows correspond to each of the positions P 1 through P 4 , wherein the position P 1 through P 4 in the case of the columns are the actively speaking persons and in case of the rows are the actively listening persons. Some of the matrix elements characterize the desired level of the attenuation for the given transmission path. The others represent the propagation time and/or delay time associated with the given transmission path. The stated values are exemplary of the different transmission paths that have been observed in a standard automobile. Thereby the measured values are measured based upon the transmission function of signal S from approximately 300 Hz to approximately 2 kHz. It becomes clear, that near the position P 1 through P 4 the persons and their roll—speaker or listener—determines the derogation of the signal propagation. For example there is a loss of about 16 dB if the person in position P 1 speaks and the person behind him in position P 3 listens. When the positions P 1 and P 3 interchange the roll as speaker and listener, a loss of about 13 dB results. The attenuation element 10 as well as delay element 12 is adjusted depending upon the values stored in the attenuation matrix corresponding to the given transmission path. Consequently the required amplification of the signal level for the acoustical path A 1 or A 2 is determined especially simply and quickly, whereby the need for an especially complex or costly signal processor is avoided.
In the attenuation matrix according to Table 1, the acoustical transmission path between each laterally adjacent positions P 1 –P 2 and P 3 –P 4 , respectively, will not be reinforced. The transmission function will be treated as adequately good for communications. Depending upon the size of the room 1 , the number of positions P 1 through P 4 , the number of microphones M 1 through M 4 as well as the loudspeaker L 1 through L 4 may vary, and accordingly, the number of possible transmission paths and matrix elements of the attenuation matrix may vary. Besides this, further parameters of the transmission function can be included in the attenuation matrix such as, for example, signal type, disturbance signal.
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For an especially low loss and echo free communication between several participants in a room ( 1 ) an inventive process for the compensation of losses of a signal(S) along a transmission path between at least one transmission point ( 6 ) and one receiving point ( 4 ) in a room ( 1 ) determining the transmission path of signal (S) and via the transmission paths at least one parameter of an associated transmission function will be determined, whereby via the determined parameters the signal level for a given position (P 1 through P 4 ) on the transmission path is controlled. Additionally an especially suitable device is provided for the implementation of the process.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/171,815, filed Jun. 5, 2015, the disclosure of which is hereby incorporated herein in its entirety by this reference.
TECHNICAL FIELD
[0002] The application relates to a method for preparing electroprocessed composition functionalized with bioactive materials, the electroprocessed composition itself, and methods of using the electroprocessed composition.
BACKGROUND
[0003] Nanofiber has a huge potential for wide applications in the water, air, medical and commodity industries. Typical examples of medical application include artificial organ components, tissue engineering, implant material, drug delivery, wound dressing, and medical textile materials. For additional applications, protective materials or coating include sound absorption materials, protective clothing against chemical and biological warfare agents, and sensor applications for detecting chemical agents.
[0004] However, improvements and new functionalities are desired in order to enhance the properties of nanofibers and its wide application.
[0005] Several methods have been proposed to improve or add desired functionalities to nanofiber.
Chemical Modification of Nanofiber Surface
[0006] Many attempts have been made for the surface modification of nanofiber or incorporation of functional materials to nanofiber. For example, hydrophilic modification of hydrophobic PVDF nanofiber by grafting a hydrophilic polymer such as epoxide-containing polymer or polyethylene glycol to a PVDF nanofiber in order to improve its mechanical strength and hydrophilicity has been suggested.
[0007] While chemical modification permanently adds hydrophilic groups to the PVDF membrane by covalent bonding, the nanofibers created by such modification have disadvantages. The modification reaction often has a low yield and poor reproducibility. In addition, many times, toxic chemicals are used in the modification reaction. Still further, the process may be lengthy and costly.
[0008] An alternative approach to improving the functionality of a nanofiber, for example, PVDF membranes, is to blend another polymer with hydrophobic PVDF. Components that can be blended with PVDF include cellulose acetate, sulfonated polysulfone, glycerol monoacetate, glycerol diacetate, glycerol triacetate, and sulfonated polyetherketone. (See U.S. Pat. No. 6,024,872 and U.S. Pat. No. 8,931,647, the contents of each of which are incorporated herein by this reference.)
[0009] The polymer blend approach has a lower cost and higher efficiency than chemical modification. However, the polymer blend approach has some drawbacks. Because there is no covalent bonding between the PVDF and the hydrophilic components, it is often found that membrane performance deteriorates with time due to a gradual loss of hydrophilic components from the membrane matrix. (See, U.S. Pat. No. 9,309,367 and U.S. Publication No. 2015/0210816, the contents of each of which are incorporated herein by this reference.)
[0010] Another method that has been suggested is surface coating. For example, a hydrophobic PVDF membrane may be coated with a water-insoluble vinyl alcohol-vinyl acetate copolymer or water soluble polymer such as polyvinylpyrolidone (PVP). (See, U.S. Pat. Nos. 5,151,193, 5,834,107 and 4,399,035, the contents of each of which are incorporated herein by this reference, where PVP is used as an additive to fabricate a PVDF membrane.) The coating layer, however, is more vulnerable to free chlorine attack than PVDF. Therefore, after frequent exposure to a cleaning reagent containing free chlorine, such as bleach, the hydrophilic-coated membrane becomes hydrophobic.
BRIEF SUMMARY
[0011] Disclosed is an electroprocessed functional composition, the functional composition comprising a structural component and a functional component.
[0012] The structural component is an electroprocessable polymer. The polymer may be, synthetic or naturally occurring, a hydrophilic or hydrophobic polymer.
[0013] The functional component is DOPA™-containing material, derived from a naturally occurring polymer or synthetic polymer. DOPA™-containing material can be selected from polydopamine homopolymer or its copolymer as synthetic material, mussel adhesive protein, or mixture of polydopamine and mussel adhesive protein.
BRIEF DESCRIPTION OF DRAWINGS
[0014] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0015] FIG. 1 illustrates the photographs of chemically cross-linked MAPTRIX® ECM hydrogel with 8 ARM-SG-20K.
[0016] FIG. 2 indicates the kinetic of dopamine in a weak acidic condition is very low.
[0017] FIG. 3 shows scanning electron microscope (SEM) images of representative PVDF fibers of the invention electrospun from PVDF/MAPTRIX® and PVDF/polydopamine solution.
[0018] FIG. 4 , Columns A and B, show water droplets formed on the nanofiber membrane of PVDF alone and PVDF functionalized with DOPA™-containing material, respectively.
[0019] FIGS. 5A and 5B show the DSC curves of pure PVDF and functionalized PVDF membrane.
[0020] FIG. 6 , Panels A-D, are petri dishes showing reduction measurements against gram-positive ( Staphylococcus aureus ) bacteria. Panel A is the control; Panel B is 5 mg; Panel C is 10 mg; and Panel D is 20 mg.
DETAILED DESCRIPTION
[0021] Described is an electroprocessable functional composition comprising a structural component and at least one or more functional components, wherein the structural component is electroprocessable, and the functional component is a DOPA™-containing motif
Hydrophilic Polymer as a Structural Component
[0022] Any hydrophilic polymer can be used in the disclosure. For example, an acrylic resin, a methacrylic resin, a polyvinyl acetal resin, a polyurethane resin, a polyurea resin, a polyimide resin, a polyamide resin, an epoxy resin, a polystyrene resin, a novolac type phenolic resin, a polyester resin, a synthesis rubber and a natural rubber can be used for the disclosure. The hydrophilic polymer may be a copolymer and the copolymer may be a random copolymer.
Hydrophilic Polymer as a Structural Component
[0023] Hydrophilic polymers useful for electroprocessing composition in the disclosure include synthetic biocompatible polymers including polyethylene glycol polymers and polyethylene oxide polymers.
[0024] In one embodiment, the polyethylene glycol has a molecular weight of from about 40 kDa to about 300 kDa. In one embodiment, the fiber includes about 35 wt % mussel adhesive protein and about 65 wt % polyethylene oxide.
Hydrophobic Polymer as a Structural Component
[0025] Any hydrophobic polymer can be used herein. A suitable hydrophobic polymer is a polyacrylate, polyolefin, silicone adhesive, natural or synthetically derived rubber base or a polyvinyl ether or a blend thereof Preferably, the hydrophobic polymer is a PVDF, PES,
Functional Component
[0026] Any 3,4-dihydroxy-L-phenylalanine (DOPA) or its derivative such as dopamine-containing material can be used for the disclosure. For example, synthetic polydopamine or mussel adhesive protein, naturally occurring or recombinantly expressed, can be used herein.
[0027] Polydopamine formed by the oxidation of dopamine has several advantages for this disclosure, as seen with mussel adhesive protein. For example, it can adhere to most surfaces of inorganic and organic materials, including superhydrophobic surfaces such as TEFLON® or PVDF (polyvinylidene fluoride). Another feature of polydopamine is in its chemical structure that incorporates functional groups such as catechol, amine, and imine. (See Yanlan Liu, et al., Chem. Rev. 2014, 114:5057-5115, “Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields”; Haeshin Lee, et al., Science 318:426 (2007), “Mussel-Inspired Surface Chemistry for Multifunctional Coatings.”)
[0028] Any suitable mussel adhesive protein as a functional component may be used as the functional component in the disclosure. The mussel adhesive proteins are commercially available materials and are obtained from synthetic or natural sources. Examples of commercially available proteins include MAPTRIC® ECM marketed by Kollodis BioSciences, Inc. (North Augusta, S.C.). Preferably, MAPTRIX® is used in the disclosure.
[0029] As used herein “MAPTRIX®” refers to a recombinant mussel adhesive protein selected from FP-1, FP-2, FP-3, FP-4, FP-5, FP-6 and its fragment or fusion of each mussel adhesive protein. The FP-1 comprises an amino acid sequence of SEQ ID NOS:1-3. The FP-2 comprises SEQ ID NO:4, the FP-3 comprises SEQ ID NOS:5-8, the FP-4 comprises SEQ ID NO:9, the FP-5 comprises SEQ ID NOS:10-13, and the FP-6 comprises SEQ ID NO:14.
[0030] MAPTRIX® is a chimeric polypeptide comprising a mussel adhesive protein and a functional peptide coupled to the mussel adhesive protein. The functional peptide can be synthetic or naturally occurring protein-derived. More preferably, MAPTRIX® ECM is used for the disclosure.
[0031] The MAPTRIX® ECM is a mussel adhesive protein recombinantly functionalized with bioactive peptides, a fusion protein comprising a first peptide of mussel foot protein FP-5 (SEQ ID NO:5) that is selected from the group consisting of SEQ ID NOS:10-13 and a second peptide of at least one selected from the group consisting of mussel FP-1 selected from the group consisting of SEQ ID NOS:1-3, mussel FP-2 (SEQ ID NO:4), mussel FP-3 selected from the group consisting of SEQ ID NOS:6-8, mussel FP-4 (SEQ ID NO:9), mussel FP-6 (SEQ ID NO:14) and fragment thereof, and the second peptide is linked to C-terminus, N-terminus or C- and N-terminus of the FP-5. Preferably, the second peptide is the FP-1 comprising an amino acid sequence of SEQ ID NO:1.
[0032] Mussel adhesive protein useful in electroprocessing the composition in the invention is a chimeric polypeptide comprising a mussel adhesive protein and a biofunctional peptide coupled to the mussel adhesive protein. The biofunctional peptide is linked to C-terminus, N-terminus or C- and N-terminus of the mussel adhesive protein. The biofunctional peptide useful in making the fibers of the invention an ECM mimic is derived from a cell binding domain or heparin binding domain of fibronectin. In one embodiment, the biofunctional peptide is a peptide having an amino acid sequence of SEQ ID NO:4. The examples of cell binding domain of fibronectin are RGD (SEQ ID NO:22) and GRGDSP (SEQ ID NO:23). The biofunctional peptide useful in making the fibers of the invention an ECM mimic is derived from laminin, collagen or vitronectin. The biofunctional peptide is selected from the group consisting of peptides comprising an amino acid sequence of SEQ ID NOS:22-28. The biofunctional peptide is a peptide having an amino acid sequence of RGD (SEQ ID NO:22), a peptide having an amino acid sequence of GRGDSP (SEQ ID NO:23), a peptide having an amino acid sequence of PHSRN-RGDSP (SEQ ID NO:27), a peptide having an amino acid sequence of SPPRRARVT (SEQ ID NO:24), and a peptide having an amino acid sequence of KNNQKSEPLIGRKKT (SEQ ID NO:26).
[0033] In another embodiment, the biofunctional peptide useful in making an antimicrobial nanofiber membrane can be selected from KLWKKWAKKWLKLWKA (SEQ ID NO:27), FALALKALKKL (SEQ ID NO:28), ILRWPWWPWRRK (SEQ ID NO:29), AKRHHGYKRKFH (SEQ ID NO:30), KWKLFKKIGAVLKVL (SEQ ID NO:31), LVKLVAGIKKFLKWK (SEQ ID NO:32), IWSILAPLGTTLVKLVAGIGQQKRK (SEQ ID NO:33), GIGAVLKVLTTGLPALISWI (SEQ ID NO:34), SWLSKTAKKGAVLKVL (SEQ ID NO:35), KKLFKKILKYL (SEQ ID NO:36), GLKKLISWIKRAAQQG (SEQ ID NO:37), GWLKKIGKKIERVGQHTRDATIQGLG IAQQAANVAATAR (SEQ ID NO:38), and RRWWCRC (SEQ ID NO:39).
[0034] The mussel adhesive protein-based fiber of the invention includes a hydrophilic polymer to facilitate production of the fiber by electrospinning. Hydrophilic polymers useful in making the fiber of the invention include synthetic biocompatible polymers including polyethylene glycol polymers and polyethylene oxide polymers. In one embodiment, the polyethylene oxide or polyethylene glycol has a molecular weight of from about 30 kDa to about 300 kDa. In one embodiment, the fiber includes about 30 wt % mussel adhesive protein and about 70 wt % polyethylene oxide. In another embodiment, the fiber includes about 30 wt % mussel adhesive protein and about 70 wt % polyethylene glycol.
[0035] The electroprocessing can be any one selected from among electrospinning, electrospray, electroblown spinning, centrifugal electrospinning, flash-electrospinning, bubble electrospinning, melt electrospinning, and needleless electrospinning.
[0036] Hydrophilic conversion of a superhydrophobic surface was easily achieved by polydopamine, a functional polymeric mimic of the mussel adhesive protein Mytilus edulis foot protein-5 (Mefp-5). This superhydrophobic surface modification is compatible with widely used soft-lithographic techniques such as MIMIC to enable facile functionalization of superhydrophobic surfaces. The modified surface remained superhydrophobic but showed high water adhesion properties. A general approach to determine surface energy of the modified superhydrophobic surface was demonstrated. Finally, the modified superhydrophobic surface can be used as a part of a water-capturing device that mimics the mechanism of collecting water shown in the cuticle of the Namib desert beetle. This new superhydrophobic surface chemistry can be applied to potentially advance superhydrophobic surface engineering for a variety of applications.
[0037] Fouling occurs when certain impurities in water deposit on a membrane's surface or in its internal pore structure. This deposition leads to a dramatic reduction in permeate flux, requiring periodic chemical cleanings resulting in increased operating costs and decreased membrane life. New membrane materials and treatments are researched to help reduce foulant adhesion. Recently, very thin coatings of polydopamine, polydopamine+PEG (Freeman et al. U.S. Pat. No. 8,017,050 issued Sep. 13, 2011) and hydroquinone, catechol, or mixtures of hydroquinone, catechol, and/or polydopamine (Freeman et al., non-provisional patent application Ser. No. 12/939,764) onto the surface of commercial microfiltration, ultrafiltration, nanofiltration, and reverse osmosis membranes have shown significant reduction in membrane fouling. A multi-year research program at the University of Texas resulted in filing of the above patents and patent applications in addition to a graduate thesis for Dr. Bryan McCloskey. Key findings of his research are published in a paper McCloskey et al., “Influence of Polydopamine Deposition Conditions on Pure Water Flux and Foulant Adhesion Resistance of Reverse Osmosis, Ultrafiltration, and Microfiltration Membranes,” Polymer 51:3472-3485 (2010). In addition, more work on the subject matter was pursued by Z. Y. Xi and published as “A facile method of surface modification for hydrophobic polymer membranes based on the adhesive behavior of poly(DOPA) and poly(dopamine),” Journal of Membrane Science (2009). Details for the above works are incorporated herein as reference. It was demonstrated in previous works that in addition to antifouling properties, these thin polymeric coatings are extremely hydrophilic and permeable to water; however, these works either did not develop or disclosed details related to 1) improvements in membrane selectivity for ion rejection and their implications; 2) capability to effectively utilize the active chemistry use during the coating of a polydopamine layer; 3) its storage, repeated and more effective use and safe disposal; and 4) effective maintainability and serviceability of the coated membranes. Advanced Hydro Inc. undertook the commercialization of the technology of the issued patent U.S. Pat. No. 8,017,050, the contents of which is incorporated herein by this reference and, through additional research, developed claims embodied in this patent application. United States Patent Publication No. 2014/0054221, the contents of each of which is incorporated herein by this reference.
Preparation of Electroprocessing Solution Containing a Hydrophobic Polymer
[0038] A hydrophobic polymer (e.g., PVdF) is dissolved in a suitable solvent at a concentration at which it can be spun, thereby preparing a spinning solution. The content of the polymer material (PVdF) in the spinning solution is preferably 5-90 wt %. If the content of the polymer material in the spinning solution is less than 5 wt % when the spinning solution is electrospun, it will form beads rather than forming nanofibers, thus making it difficult to manufacture a membrane. On the other hand, if the content of the polymer material is more than 90%, it will be difficult to form fibers, because the viscosity of the spinning solution is high. Accordingly, although the preparation of the spinning solution is not specifically limited, it is preferable that the concentration of the polymer in the spinning solution be set at a concentration at which a fibrous structure can be easily formed, thereby controlling the morphology of fibers.
Electroprocessing Procedure
[0039] The electroprocessing solution is transferred to a spin pack using a metering pump, and then electrospun by applying high voltage to the spin pack using a high voltage controller. Herein, the voltage used is adjustable within the range of 0.5 to 100 kV, and as a current collector plate, an electrically conductive metal or release paper may be used and it may be grounded or negatively charged before use. The current collector plate is preferably used together with a suction collector attached thereto in order to facilitate bundling of fibers during spinning.
[0040] In the electrospinning, the interval between the spin pack and the current collector plate is preferably controlled to 5-50 cm, and the spinning solution is discharged at a rate of 0.0001-5 cc/hole·per minute using a metering pump. Also, the electrospinning is preferably carried out at a relative humidity of 30-80% in a chamber whose temperature and humidity can be controlled. The nanofiber web spun as described above has an average fiber diameter of 50-1,000 nm.
[0041] The spinning process can be carried out using, in addition to electrospinning, electrospray, electroblown spinning, centrifugal electrospinning, flash-electrospinning, bubble electrospinning, melt electrospinning, or needleless electrospinning.
[0042] E. coli -based protein expression system was commercialized recently to produce a variety of mussel adhesive proteins including FP-151 in an efficient way (see International Publication No. WO 2011/115420), and the mussel adhesive proteins are commercially available under trademark MAPTRIX® marketed by Kollodis BioSciences, Inc. The method for preparation of bioactive mussel adhesive proteins are fully described in International Publication No. WO/2011/115420, which is hereby incorporated by reference for all purposes as if fully set forth herein.
EXAMPLES
Example 1
Polydopamine Precursor Preparation
Characterization of the Dopamine Polymerization by UV-Vis Spectra
[0043] The reactivity of dopamine was measured at room temperature using UV-vis spectroscopy (U-200A, Shanghai Spectrum Instruments Co., Ltd, shanghai, China) at the wavelengths from 250 to 600 nm.
[0044] The DA·HCl concentration was 1 mg/ml in all experiments. For the UV spectroscopy measurements, the samples were prepared by 1:19 (v/v) dilution of the DA solution with distilled water. In the “pH-induced” control experiment, 2 mg/ml DA·HCl was added into the Tris-HCl buffer (pH 8.5).
[0045] To investigate the DA polymerization in weak acidic, neutral and weak alkaline aqueous media, 2 mg/ml DA and 1.2 mg/ml AP (the molar ratio of AP to DA was 1:2) were added into the buffer solutions of pH 5.5 (Disodium hydrogen phosphate-citric acid buffer), pH 7.0 (Disodium hydrogen phosphate-citric acid buffer) and pH 8.5 (Tris-HCl buffer) for a 2-hour polymerization. For the UV spectroscopy measurements, the operation was the same as above. The experiments for sodium periodate and potassium chlorate-induced DA polymerization was the same as for AP.
Example 2
Electroprocessing of Functional Composition
a) Composition: MAPTRIX®/PEO Nanofiber
[0046] Poly(ethylene oxide) (PEO) with an average molecular weight of 600,000 was from Sigma (St. Louis, Mo., USA). 4 wt % mussel adhesive protein (MAPTRIX®, Kollodis BioSciences, Inc. MA) solutions and 4 wt % PEO solutions were prepared separately by dissolving mussel adhesive protein and PEO in distilled water, followed by filtration through a 5 syringe filter to remove remaining insoluble materials. The mussel adhesive protein and PEO solutions of different proportions were then mixed to obtain mixtures with weight ratios of mussel adhesive protein to PEO in the range 40:60-90:10, and the resultant mixtures were stirred for at least 30 minutes. Solutions containing 2 wt % urea were mixed with mussel adhesive protein-PEO blend solutions, and the mixtures were stirred for an additional 30 minutes and filtered to remove remaining insoluble materials before use in electrospinning. Electrospinning was performed with a steel capillary tube with a 1.5 mm inside diameter tip mounted on an adjustable, electrically insulated stand as described in H -J. Jin et al., Biomacromolecules 3 (2002), pp. 1233-1239. Briefly, a DC voltage of 15-22 kV with low current output (High DC power supply, Nano NC Corp., Ansan, Korea) was applied between the syringe tip and a cylindrical collector. The typical distance between the syringe tip and the grounded collector was 15-20 cm. The electrospinning solution inside the syringe was charged with a positive voltage by dipping a platinum wire into the solution from a positive lead; the cylindrical collector was grounded.
b) Composition: MAPTRIX®/HA/PEO
[0047] Mussel adhesive protein, hyaluronic acid (HA), and polyethylene oxide (PEO) powder were dissolved in 0.1 N NaOH at concentrations of 5, 2, and 4 wt %, respectively. Hyaluronic acid solution was then added into the PEO/NaOH solutions at a concentration of 1.0% (w/v) and dissolved using a vortex mixer (Vortex-genie2, Scientific Industries, Inc.) for 20 minutes until the solution became clear. The MAPTRIX®/HA/PEO blend solutions with different weight ratios from 1/1/1 to 1/1/3 were prepared for electrospinning. The same electrospinning conditions were applied.
c) Composition: PVDF/MAPTRIX®
[0048] MAPTRIX® solution was prepared by dissolving mussel adhesive protein (10 mg) in 1 mL distilled water and followed by the addition of dimethyl acetamide (DMAc) to the MAPTRIX® solution.
[0049] PVDF (MW: 400,000 da) was dissolved in DMAc at 80° C. with magnetic stirring for 12 hours to form a 20 wt % (w/v) electrospinning solution. The MAPTRIX® solution (1 mL) was added to the PVDF solution (4 mL) to get 5 mL of electroprocessable functional composition.
[0050] The electroprocessable composition was transferred to a spin pack using a metering pump, and then electrospun by applying high voltage to the spin pack using a high voltage controller. The voltage used here was adjustable within the range of 19 to 20 kV, and as a collector plate, an electrically conductive metal was used.
[0051] FIG. 3 shows scanning electron microscope (SEM) images of representative PVDF fibers of the invention electrospun from PVDF/MAPTRIX® and PVDF/polydopamine solution.
d) Composition: PVDF/Polydopamine Precursor
[0052] 21 mg of dopamine was dissolved in distilled water (1 mL) and very slow oxidation reaction was allowed for 3 to 6 hours to form a precursor. As described in FIG. 2 , the kinetic of dopamine in a weak acidic condition was very low.
[0000]
Code
Precursor
Precursor treatment
E-spin solution
1
M2 mg
MD91-0.5 H
PVDF 4 mL + Precursor 1 mL
2
M2 mg
MD82-0.5 H
PVDF 4 mL + Precursor 1 mL
3
M2 mg
MD91-0.5 H
PVDF 4 mL + Precursor 1 mL
4
D21 mg
DA91-3 H
PVDF 4 mL + Precursor 1 mL
5
D21 mg
DA82-3 H
PVDF 4 mL + Precursor 1 mL
6
D21 mg
DA73-3 H
PVDF 4 mL + Precursor 1 mL
7
D21 mg
DA91-6 H
PVDF 4 mL + Precursor 1 mL
8
D21 mg
DA82-6 H
PVDF 4 mL + Precursor 1 mL
9
D21 mg
DA73-6 H
PVDF 4 mL + Precursor 1 mL
Note:
Precursor: M indicates mussel adhesive protein and D indicates dopamine
Precursor treatment: MD indicates DMAc/water as a solvent and DA indicates acetone/water as a solvent to make a precursor and H means the reaction time.
Example 3
Surface Characterization of Electroprocessed Composition
[0053] PEO/MAPTRIX® composition makes hydrophilic nanofiber membrane and thus its contact angle was measured. The surface contact angles were measured on a Drop Shape Analysis System (DSA100) (KRUSS, Germany). Deionized water was dropped onto the sample from a needle on a microsyringe during the test. A picture of the drop was captured after the drop set onto the sample. The contact angle was calculated by the software through analyzing the shape of the drop. The contact angle was an average of 5 points.
[0054] FIG. 4 , Columns A and B, show water droplets formed on the nanofiber membrane of PVDF alone and PVDF functionalized with DOPA™-containing material, respectively. The surface contact angle of the pure PVDF nanofiber membrane is 120°, in agreement with the strong hydrophobicity of PVDF material to water. A significant decrease in the contact angle on the functionalized PVDF membrane is ascribed to the presence of a hydrophilic group, such as —COOH, —OH, NH2.
Example 4
Thermal Analysis
[0055] The melting temperature and crystallization temperature of the PVDF membranes was characterized by differential scanning calorimeter (Perkin-Elmer DSC-7, Wellesley, Mass., USA). The heating rate was set to 10° C./minute.
[0056] FIG. 5 shows the DSC curves of pure PVDF and functionalized PVDF membrane. Both samples have melting peak at 165° C. Functionalization of PVD did not affect melting temperature but a slight change in crystallization temperature was observed even though the difference was small, indicating the crystallization behavior was not influenced by the presence of precursors such as MAPTRIX® or polydopamine precursor.
Example 5
Preparation of Antimicrobial Nanofiber and Antimicrobial Assay
[0057] A composition comprising PVDF and mussel adhesive protein functionalized with antimicrobial peptide was prepared for electroprocessing. The composition was prepared and electroprocessed as described in EXAMPLE 1. The electrospun composition is an antimicrobial nanofiber membrane.
[0058] One gram of antimicrobial nanofiber membrane (1 mm×1 mm) and 5 mL of a liter of 4.6×105 CFU/ml of Staphylococcus aureus is added to 70 ml test tube containing phosphate buffer and was then placed on a Burrell Wrist Action Shaker for one hour. Reduction measurement indicates that the nanomembrane was effective against the gram-positive ( Staphylococcus aureus ) bacteria even though the reduction percentage was about 50% as seen in FIG. 6 . An electroprocessing of antimicrobial composition with optimal concentration of antimicrobial mussel adhesive protein can make its nanofiber membrane effective against the bacteria.
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Described are methods for preparing an electroprocessed composition functionalized with bioactive materials and the use of the electroprocessed composition, including use as an engineered extracellular microenvironment and its use in forming three-dimensional matrix for biological application. The electroprocessed composition may also be combined with other molecules in order to deliver substances to the site of application or implantation of the electroprocessed composition.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a motorized lock for flaps or doors of motor vehicles, especially a lock for a glove compartment.
2. Description of the Related Art
The motorized lock of the aforementioned kind has a rotary spagnolet in which, during closing of the flap, a locking member is inserted and rotates the rotary spagnolet out of an open pivot position, characterizing the open position of the flaps via a split position of the flap into a closed position determining the locked position of the flap, with a locking pawl having a rotating latch connected rotationally fixedly to the rotary spagnolet when the locking pawl is active and when the rotary unit, comprised of the rotary spagnolet and the rotating latch, has been transferred out of its open pivot position, with the flap in the open position, either into a pre-locking position determining the split position of the flap or into a closed pivot position defining the locked position of the flap.
SUMMARY OF THE INVENTION
Even though for locks of different kinds motor-driven closing and opening aids are known, these are not suitable for a lock of the kind mentioned in the preamble. According to the invention, a motor is used as a closing and, if needed, also an opening aid wherein a special gear mechanism acts via shoulders onto correlated counter shoulders of a catch. The catch is a component of a rotary unit which, in addition to the catch, also comprises a rotating latch cooperating with a locking pawl and a closing member cooperating with a rotary spagnolet. The gear mechanism has a position-changeable gear group which, relative to the rest of the gear mechanism, is adjustable between an engagement position and a separating position. In the closed or open position of the flap the rotary unit is in a final locking position or an initial position but the drive member of the gear mechanism having the shoulders is always transferred into a defined ready position. In it a free space is provided between the shoulders and the counter shoulders so that the flap can be easily opened or closed manually. In this connection, the gear mechanism is in a separating position so that a possible self locking action in the drive chain between the motor and the drive member is canceled. The flap can be manually moved farther in any intermediate position in which an emergency situation occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention result from the claims, the following description, and the drawings. In the drawings, an exemplary embodiment of the invention is illustrated. It is shown in:
FIG. 1 a schematic view of the lock according to the invention;
FIG. 2 in a side view essential components of the lock in a first position;
FIG. 2 a a cross-section of a part of the lock of FIG. 2 along the indicated section line IIa—IIa;
FIG. 2 b an axial section along the section line IIb—IIb, indicated in FIG. 4, of a part of the lock with broken-away portions;
FIG. 3 the side view according to FIG. 2 with the lock parts in a second position;
FIG. 4 a the axial plan view onto the lock and the viewing direction of arrow VIa of FIG. 2 with the lock parts in a ready position for closing a flap;
FIG. 4 b a plan view corresponding to that of FIG. 4 a, wherein the two uppermost components of a rotary unit belonging to the lock, i.e., a rotary spagnolet and a rotating latch, cannot be seen but are illustrated by a dash-dotted line, which view corresponds to a section taken along the section line VIb—VIb of FIG. 2;
FIGS. 5 through 8 a, in a representation corresponding to FIG. 4 b, three further positions of the lock parts which result during closing of the flap provided with a closing member of this lock, wherein FIG. 8 a shows the ready position of the lock parts for opening when the flap is closed;
FIG. 8 b shows the same rotational position of the lock parts as FIG. 8 a but in an emergency situation for a manual opening of the flap or for illustrating an alternative function of this lock;
FIGS. 9 through 12 the lock parts in four further rotary positions which result for a motor-driven opening of the flap; and
FIG. 13 the same illustration of the lock parts as in FIG. 11 but in an alternative application where, instead of the motor, return springs can return the lock parts again into their ready position for closing the flap according to FIG. 4 b.
DESCRIPTION OF PREFERRED EMBODIMENTS
The lock illustrated in the Figures is used preferably for a flap which belongs to a glove compartment. Accordingly, in FIG. 1 the movable flap 11 and the stationary compartment rim 12 are illustrated schematically. In the present case the movable flap 11 supports the frame with a closing member 10 , here in the form of a bolt with a round cross-section while the compartment rim 12 has a lock housing 19 from which the rotary latch 22 projects which cooperates with the closing member 10 . It is understood that the lock parts 10 , 19 can also be arranged mirror-symmetrically relative to the movable and stationary elements 11 , 12 of the glove comfort and.
The most important lock parts provided in the lock housing 19 are illustrated in FIGS. 2 to 4 b. In the lock housing 19 an axle shaft 13 is rotatably supported which forms a component unit 20 of several components 21 to 23 which are fixedly connected to one another. The component 20 is thus a part which is rotatable in its entirety and is therefore in the following referred to as a rotary unit. This rotary unit 20 includes first the fork-shaped rotary spagnolet or latch member 21 whose fork opening during closing of the flap, according to the movement arrow 15 illustrated in FIG. 4 a, is engaged by the closing member 10 . At an axial spacing thereto in the interior of the lock housing 19 a rotating latch 22 is provided which has a pre-locking stage 24 and a final locking stage 25 for a pivotable locking pawl 16 . The locking pawl 16 is spring-loaded in the direction of arrow 17 in the direction toward the rotating latch 22 . Moreover, the entire rotary unit 20 is spring-loaded in the direction of opening of the rotary spagnolet 21 as illustrated in FIG. 4 a via the force arrow 27 . The fully open position of the rotary spagnolet 21 illustrated in FIG. 4 a is limited by a schematically indicated stop 26 in the housing against which the spring load 27 normally forces the rotary spagnolet 21 . This open pivot position is present in the open position of the flap.
In the lock housing 19 a gear mechanism 30 acted on by an electric motor 40 is positioned. The gear mechanism 30 comprises several gear groups of which one special gear group 36 can be position-changed, in particular, in the present case by tilting as can be seen when comparing FIGS. 2 and 3. The input member of the gear mechanism 30 is a worm driven by the motor 40 and engages a worm wheel 31 . The worm wheel 31 is connected fixedly with spur gears 32 and is freely rotatable on the axle shaft 13 . The spur gear 32 meshes with a gear 33 which is seated fixedly on the pinion 34 . The component group 36 of the gear mechanism parts 33 , 34 has a shaft 14 which in a first type of application of the lock, extends normally parallel to the axle shaft 13 . In this case, the pinion 34 meshes with the drive member 35 of the gear mechanism 30 which is also formed as a spur gear. Accordingly, the gear group 36 is in an active engagement position where the rotation exerted by the motor 40 is transmitted onto the drive member 35 .
As illustrated in FIG. 3, the component group 36 can be moved into a tilted position 36 ′ by an actuator 50 comprising several members which tilted position is pivoted by an angle 18 according to FIG. 3 and in which the pinion 34 engages no longer the toothing of drive member 35 . The self locking action of the gear mechanism 30 is canceled. The tilted position 36 ′ of this gear group can be referred to as “separating position”.
The drive member 35 is hollow as can be seen best in FIG. 2 b and serves for receiving the catch 23 of the rotary unit 20 . The drive member 35 is provided with an axial cam 37 whose axial end face is enhanced for illustration purposes in FIGS. 4 a through 13 by dotted shading. This cam 37 defines a radial control surface 47 . Moreover, the drive wheel 35 has two shoulders 38 , 39 which can be seen in FIG. 4 b and which have correlated therewith two counter shoulders 28 , 29 on the rotating latch 22 . The two shoulders 38 , 39 of the drive member 35 as well as the two counter shoulders 28 , 29 are opposite relative to one another, respectively, as can be seen in FIG. 4 b. It is important in this connection that between the shoulder and the counter shoulder 28 , 38 an angle-shaped free space 48 is provided. A corresponding free space 49 is also provided between the other pair 39 , 29 of the two shoulders and counter shoulders.
In FIGS. 4 a, 4 b the drive member 35 is in a ready position for closing the flap which is in its fully open position. In the ready position of FIG. 4 a, the locking pawl 16 is supported as a result of the aforementioned spring loading 17 at the peripheral surface 42 of the rotating latch 22 . The flap is moved first manually in the direction of its closed position wherein the locking bolt 10 provided on it is moved in the direction of the already mentioned arrow 15 and thus impacts on the rotary spagnolet 21 and thus entrains it. First, a manual closing pivot movement of the rotary spagnolet 21 in the direction of arrow 15 of FIG. 4 a takes place wherein the entire rotary unit 20 , i.e., including the catch 23 , is pivoted against the spring load 27 . The counter shoulder 28 thus moves away increasingly from the shoulder 38 belonging to the drive member 35 . The drive member 35 remains in the rest position until the position of the rotary unit 20 illustrated in FIG. 5 has been reached.
In FIG. 5, the rotary unit 20 is in a so-called pre-locking position where the pawl 16 has dropped, as a result of its spring load 17 , into the pre-locking stage 24 of the rotating latch 22 illustrated in a dash-dotted line. In this case, a “split position” of the flap is present. In FIG. 5, as a result of the manual movement 58 the counter shoulder 28 has moved away from the shoulder 38 to a maximum degree. This pre-locking position is detected by sensors which now supply current to the motor 40 . Via the gear mechanism 30 the drive member 35 is now rotated father in the direction of closing 58 of FIG. 5 . Now the shoulder 38 of the drive wheel 35 impacts on the counter shoulder 28 of the catch 23 . Accordingly, the entire rotary unit 20 is pivoted, as illustrated in FIG. 6 . In this connection, the pre-locking stage 24 of the rotating latch 22 moves away from the spring-loaded locking pawl 16 . Since the locking bolt 10 has been moved already sufficiently into the fork opening of the rotary spagnolet 21 , it is now entrained by the closing pivot movement 58 of the rotary spagnolet 21 so that the flap now is closed by motor drive action.
In FIG. 7 the motor-driven closing pivot movement 58 is completed via the drive member 35 . The rotary unit 20 with its rotary spagnolet 21 is now in a final locking position. The locking pawl 16 has dropped into the final locking stage 25 of the rotating latch 22 . This is now detected by sensors which slow down the motor. Moreover, in this type of application the rotary direction of the motor is reversed; a reverse rotation results by which, via the gear mechanism 30 , the drive wheel 35 is first rotated back in the opening pivot direction according to arrow 59 of FIG. 7 . This return rotation however does not include the rotary unit 20 . The rotary spagnolet 21 and the locking bolt 10 engaged by it remain in the completely closed pivot position and secure the locking bolt 10 . Accordingly, the completely closed position of the flap is secured.
The latter remains in place when the drive member 35 finishes its return rotation in the direction 59 of the opening pivot direction according to FIG. 8 a. This can be detected and triggered by sensors. In this position, the shoulder 38 of the drive member 35 has moved away from the counter shoulder 28 of the catch 23 . A large free space defined by the angle 61 in FIG. 8 a is present therebetween. Also, between the shoulders and counter shoulders 39 , 29 , not yet active at this point, a free space defined by the angle 62 is provided. The same rotational position of the drive member 35 as in FIGS. 4 a, 4 b is presented as illustrated with the aid of the position of the cam 37 shown in dotted shading. The position of the rotary unit 20 however is opposite; while in FIGS. 4 a, 4 b the completely open initial position is present, the rotational unit 20 in FIG. 8 a is shown in its completely closed final locking position. In FIG. 8 a the drive member 35 is again in its ready position, as in FIGS. 4 a, 4 b; however, for opening the flap in the direction of the opening arrow 59 illustrated on the rotary spagnolet 21 . The manual opening of the flap, however, is initially not possible because the drive member 35 engages the other members of the gear mechanism 30 , and between these members a self locking action is present. Primarily, the movement in the opening pivot direction 59 is prevented because of the locking pawl 16 securing the rotary unit 20 by means of the rotating latch 22 in the final locking position illustrated in FIG. 8 a. In this type of application of the invention, a motor-driven opening movement is therefore provided, as will be explained in more detail with FIG. 9 .
An emergency situation may now occur where, in the ready position of FIG. 8 or in any of the preceding or following intermediate positions of the drive member, the current supply fails and a motor-driven opening of the flap is impossible. The invention makes possible a manual opening movement by activating the special actuator 50 , already mentioned in connection with FIG. 3, and this will be explained in FIG. 8 b in more detail.
The actuator comprises first a working lever 51 , illustrated in FIGS. 8 a and 8 b, which, as illustrated in dashed lines, supports the tiltable end of the axle 14 of the indicated gear group 36 . In the normal situation according to FIG. 8 a, the working lever 51 is secured by a support lever 52 so that in connection with FIG. 2 the already described engagement position 36 of this component group is present. The actuator 50 is triggered by a manual grip, not shown, which acts on a pull cable 53 , illustrated with its end part in FIGS. 8 a, 8 b, of the Bowden cable 54 . The pull cable 53 engages the support lever 52 which can be transferred from its active position 52 illustrated in FIG. 8 a into its inactive position 52 ′ illustrated in FIG. 8 b. The working lever in this connection is under the action of a lifting spring illustrated by the force arrow 57 which in the case of the working lever illustrated in FIG. 8 b is pivoted into the pivoted-away position 51 ′. By doing so, the gear group reaches the tilted position, shown in FIG. 3 and illustrated by the end of the axle 14 , which tilted position characterizes the separating position of the gear mechanism 30 . The gear mechanism 30 is decoupled so that the self locking action is canceled. The drive member 35 can therefore be moved without motor in the direction of the arrow 59 in the opening pivot direction as illustrated in FIG. 8 b. This is automatically carried out in this situation by means of a return spring 44 , illustrated in FIGS. 2, 2 a, which engages with its two spring legs 43 two pins 45 , 46 and ensures their radial alignment according to FIG. 2 a. One pin 45 is seated on the drive member 35 , while the other pin 46 is fastened to the housing, i.e., is positioned in the interior of the lock housing 19 indicated in FIGS. 2 a and 2 . As indicated in FIG. 8 b, the pivoting-away movement of the working lever into its pivoted-away position 51 ′ is realized by a coupling rod 55 in correlation with the support lever which then acts in its inactive position 52 ′.
A slotted hole guiding action or the like then provides for an adjustment of the pivot movement path resulting therefrom. There is a further coupling rod 56 between the locking pawl 16 and the working lever 51 so that here a suitable longitudinal guiding also provides for an adjustment of the movements. By means of the further coupling rod 56 , according to FIG. 8 b, via the working lever having been moved into the pivoted-away position 51 ′, an adjusted pivoting-away movement of the locking pawl 16 is realized which, from its active engagement position in the rotating latch 22 according to FIG. 8 a, is pivoted into an inactive release position 16 ′ of FIG. 8 b counter to its spring load 17 . Subsequently, the rotating latch 22 is no longer blocked in its final locking stage 25 . The entire rotary unit 20 is free and can thus be moved in the direction of opening arrow 59 . This can be realized by the action of the afore described return spring 44 . Moreover, the rotary spagnolet 22 of the rotary unit 20 is subjected to the action of the spring force 27 , already mentioned in connection with FIG. 4 a, which is active in the same direction 59 . Accordingly, the rotary spagnolet 21 can again be fully open until it reaches the ready position illustrated in FIG. 4 a. This opening movement 59 releases the locking bolt 10 , and the flap is now in its fully open position.
The aforementioned cancellation of the self locking action of the gear mechanism by the separating position 36 of the gear group is important primarily when the emergency situation which caused the triggering of the actuator 50 has happened in the afore described intermediate positions according to FIGS. 6 or 7 . The automatic return of the rotary unit 20 resulting from the spring force is not possible in the direction of opening direction 59 because upon its return rotation the catch 23 impacts with a counter shoulder 28 against the shoulder 38 belonging to the drive member 35 . This is not the case in the situation of FIG. 8 a which, as mentioned above, is identical to FIG. 8 b. As has been mentioned above, the drive member 35 with its shoulders 38 , 39 is already in a position which coincides with the open position of FIGS. 4 a, 4 b. The aforementioned free space 61 is large enough in order to return the rotary unit 20 into its initial position of FIG. 4 a. Normally, this is carried out in this embodiment of the invention by a motor drive with the above-mentioned return rotation of the drive member 35 in the opening pivot direction 59 without the previously described triggering of the actuator 50 having to take place.
For a corresponding switching on of the motor 40 , for example, an electrical key is provided. When moving the drive wheel 35 in the direction of arrow 59 according to FIG. 9, the shoulder 39 of the cam 37 has moved onto the counter shoulder of the catch 23 . At the same time, the cam 37 with its control surface 47 , as illustrated in FIG. 9, has been moved against the locking pawl and has pivoted it into the aforementioned inactive position 16 ′ against the spring load. This pivoting action is without any feedback action on the aforementioned actuator 50 because the slotted hole guide is provided in the mentioned coupling rod 56 . This slotted hole guide makes the adjusting movement at the locking pawl by the control surface 47 possible, without action on the actuator 50 . The rotary unit 20 is no longer blocked by the locking pawl.
According to FIG. 10, the rotary unit 20 is further moved by the shoulder 39 of the drive motor 35 . by means of the counter shoulder 29 of the catch 23 . In this connection, the control surface 47 provided on the cam 37 maintains the locking pawl still in its inactive position 16 ′ so that an undesirable dropping into the subsequent pre-locking stage 24 of the rotating latch 22 is prevented upon further rotation 59 initiated by the motor.
Finally, the rotary unit 20 reaches the initial position shown in FIG. 11 by a motor-driven rotation 59 of the drive member 35 . The rotary spagnolet 21 is again moved into its fully open position and releases the locking bolt, as illustrated in FIG. 11 by dash-dotted lines. As illustrated by the movement arrow 60 the locking bolt 10 seated on the flap is moved away so that the flap can again reach its fully open position. On the path into the open pivoted position of FIG. 11 the pre-locking stage 24 of the rotating latch 22 is passed which is however inactive because the locking pawl is still secured by the control surface 47 at the gear mechanism side. Passing across the pre-locking stage 24 is again detected by sensors which in this embodiment of the invention slow the motor 40 and drive it again in the counter direction, i.e., in the closing direction 58 . The thus resulting conditions are illustrated in FIG. 12 in an intermediate rotational position of the drive member 35 . While the rotary unit 20 is secured by contacting of its rotary spagnolet 21 on the stop 26 as a result of spring action 27 , the shoulder 39 of the drive member 35 , which was still active previously, is moved away from the counter shoulder 29 of the catch 23 . When the drive wheel 35 is driven further in the opening direction 59 by a motor, the still active control surface 47 of FIG. 12 now passes underneath the locking pawl which is still maintained in its inactive position 16 ′. Finally, the ready position of the drive member 35 , as illustrated in FIGS. 4 a, 4 b, is reached where the control surface 47 has moved away from the locking pawl 16 and is thus supported on the circumferential surface 42 of the rotating latch 22 . The rotating latch is activated and is under pre-stress of the spring load 17 . However, in this ready position it cannot yet drop into the locking stages 24 or 25 as long as the pivot position of the rotary unit 20 is present.
FIG. 13 shows first an emergency actuation which is analog to the conditions described in connection with FIG. 8 b. While the drive wheel is still in the rotary position illustrated in FIG. 11, it is assumed that the electric power supply or the like fails and an opening or closing 58 , 59 without motor driving action is to be performed. The opening is not required in the situation of FIG. 11, but the emergency situation could also result in a preceding rotational position, for example, FIG. 10 . In this case, the locking pawl is in its inactive position 16 ′ as a result of the control surface 47 , but the already aforementioned self locking action in the gear mechanism 30 would be present, had not the gear group been transferred into the separating position 36 ′ by triggering the actuator 15 in FIG. 13 . Since this however can be triggered according to FIG. 13, the pressure contact between the shoulder 39 and the counter shoulder 29 is canceled and the return effect of the above described return spring 54 can become effective. The drive member 35 is transferred by this spring 44 automatically into its ready position according to FIGS. 4 a, 4 b. Accordingly, the rotary unit 20 reaches again its open pivot position, if it is not already present, as is the case in FIG. 13 .
The triggering of the actuator 50 according to FIG. 13 is also useful when, based on the FIGS. 4 a, 4 b, an exclusively manual closing movement 58 is to take place. The rotary unit 20 can be pivoted ( 58 ) into the closed position manually by the angular amount 63 indicated in FIG. 4 b, even though the shoulder 38 at the gear mechanism side impacts on the shoulder 28 of the catch. The free space 48 described in connection with FIG. 4 b is indeed smaller than the angular amount 63 for the rotational movement of the construction unit 20 out of the open pivot position of FIG. 4 b into the closed pivot position illustrated by a dotted line and corresponding to FIG. 7 . Also, a different operation of the invention is possible. This may reside in that the aforementioned gear group 36 is positioned normally always in the separating position 36 ′ described in connection with FIGS. 3, 8 b and 13 . This initially does not impair the two ready positions for opening according to FIG. 8 a and for closing according to FIGS. 4 a, 4 b, as has been explained before. Only when, based on the ready position for closing according to FIGS. 4 a, 4 b, a closing assistance by the motor 40 is desired, this gear group will reach its engagement position 36 so that the operation according to FIGS. 5, 6 , 7 is carried out in the already described manner. However, a simplified control then occurs. Once FIG. 7 has been reached, the motor 40 thus stops the closing movement 58 of the drive member 35 . Now the gear group 36 is transferred by a suitable control member again into its separating position 36 ′ according to FIG. 3, 8 b, or 13 where the self locking action in the gear mechanism 30 is canceled. The explained spring forces 27 or the return spring 44 then guides the drive member 35 automatically again into the ready position of FIGS. 8 a, 8 b without a current supply of the motor 40 in the opening pivot direction 59 being required. The ready position according to FIG. 8 a of the drive member 35 is realized by a spring force. Then the locking pawl 16 drops into the final locking position illustrated in FIG. 8 a and secures the rotary unit 20 .
Now the position-changeable gear group 36 can again be transferred automatically into its separating position 36 ′ of FIG. 3, wherein however first the locking pawl remains in its engagement position 16 of FIG. 8 a. In this connection, a variant relative to the conditions explained in FIG. 8 b occurs. When now the rotary unit 20 is to be transferred again into the open position according to FIG. 11 of the preceding embodiment, a motor-driven opening movement in the direction of arrow 59 is not required. It is sufficient to transfer the locking pawl 16 by a suitable control member into its inactive position 16 ′ illustrated in FIG. 8 b where the rotating latch 22 is released. The spring force 27 acting on the rotary unit 20 provides the spring-caused return movement of the rotary unit 20 . The described return spring 44 secures the drive member 35 in the ready position already illustrated in FIG. 8, which ready position is identical to FIG. 4 a and again characterizes the desired ready state for closing. This alternative operation simplifies thus the control of the motor 40 .
List of Reference Numerals
10
closing member, closing bolt
11
movable flap
12
stationary compartment rim
13
axle shaft of 20
14
tiltable axle of 36
15
movement part of 10 locked position
16
locking pawl (in engaged position)
16′
inactive position of 16, release position
17
spring loading arrow of 16
18
tilting angle between 36, 36′ (FIG. 3)
19
lock housing
20
rotary unit
21
rotary spagnolet of 20
22
rotating latch of 20
23
catch of 20
24
pre-locking stage of 16
25
final locking stage of 16
26
stop for 21
27
spring loading arrow of 21 in the opening pivot direction
28
first counter shoulder on 22
29
second counter shoulder on 22
30
gear mechanism
31
worm gear of 30
32
spur gear of 30
33
gear of 36
34
pinion of 36
35
toothed drive member of 30
36
position-changeable gear group of 33, 34 (engagement
position)
36′
separating position of 36
37
cam on 35
38
first shoulder on 35
39
second shoulder on 35
40
motor
41
worm gear on 40
42
peripheral surface of 22
43
spring leg of 44
44
return spring
45
pin on 35 (FIG. 2)
46
pin on 19 (FIG. 2)
47
radial control surface on 37
48
free space between 28, 38 (FIG. 4a)
49
free space between 29, 39 (FIG. 4b)
50
actuator
51
working lever (in the pivoted position)
51′
pivoted-away position of 51
52
support lever (in active position)
52′
inactive position of 52
53
pull cable of 54, core of 54
54
Bowden cable
55
coupling rod between 51, 52 (FIG. 8a)
56
coupling rod between 16, 51 (FIG. 8a)
57
force arrow of the lifting spring for 51 (FIG. 8a)
58
movement arrow in the closing pivot direction of 20 or 35
59
movement arrow in the opening direction of 20 or 35
60
movement arrow of 10 in the open position (FIG. 11)
61
free space between 28, 38 (FIG. 8a)
62
free space, angle between 29, 39 (FIG. 8)
63
angular amount for rotational movement of 20 (FIG. 4)
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The invention relates to a lock that can be used with a flap, comprising a rotary unit that is made up of a rotary spagnolet that interacts with a closing element ( 10 ) and a rotating latch ( 22 ). In order to improve operational performance, the rotary unit is provided with a rigid catch ( 23 ) that preferably has two counter shoulders running in opposite directions. The output member ( 35 ) of a motor ( 40 )—driven gear mechanism is also provided with two corresponding counter shoulders. This enables the motor to provide assistance with closing and, optionally, opening, whereby the rotary unit can be guided in a closing, tilting direction or an opening, tilting direction until the flap is fully closed or opened. The motor ( 40 ) comprises a gear mechanism with a group of gears that can be displaced between an engaged position and a separated position. The detent pawl ( 16 ) which interacts with the rotating latch ( 22 ) is disabled in the separated position, should an emergency arise. When the flap is in a closed or open position, a free area exists between the shoulders and counter shoulders, enabling the flap to be moved manually.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to surgical fastening apparatus, and specifically to an improved surgical fastening apparatus containing a locking means.
2. Background of the Prior Art
Surgical fastening apparatus for placing gastro intestinal anastomoses are known in the art. Such apparatus are used for suturing gastric and intestinal walls with spaced parallel rows of longitudinally aligned staples or surgical fasteners. For example, Bobrov et al. (U.S. Pat. No. 3,079,606) discloses an instrument for suturing gastric and intestinal walls with metal staples by inserting the tips of the instrument into the lumens of the organs to be sutured through apertures in the walls of the organs. The apparatus comprises a two part frame, each part having finger like projections or forks which are inserted respectively into the apertures in the walls of the organs to be sutured. The frame parts are hinged together with the body tissue held between the forks. When the instrument is actuated, longitudinally moving cam bars contact staple drive members in one of the forks, thereby pushing the surgical staples through the body tissue and into an anvil in the opposite fork. A knife blade between the cam bars creates an incision between the parallel rows of staples. It should be noted, however, that the knife blade is an optional feature. The instrument may be used to fasten body tissue without creating an incision between the rows of staples.
Green et al. (U.S. Pat. No. 3,490,675) discloses an improved instrument of type discussed above, the improved instrument laying down double rows of staples on each side of the incision.
A further improvement in this type of instrument is disclosed in Green (U.S. Pat. No. 3,499,591). The further improved apparatus incorporates an improved structure for the staple-containing cartridge, the pusher assembly which includes the cam bars and knife, and the staple driving members. The contents of the above mentioned patents are incorporated by reference herein in their entirety.
Generally, the instruments discussed above are successfully used in abdominal, gynecological, pediatric and thoracic surgery for resection, transection and creation of anastomoses. However, there is a danger during an operation that the surgeon may inadvertently insert the forks of the instrument into body organs when the instrument is empty of staples. This can occur when the instrument has already been fired but not reloaded or discarded. Under such circumstances, the cam bar and knife blade can be moved, thereby creating an unsealed incision, and causing blood loss and trauma to the patient undergoing the surgery. Non-cutting fasteners, i.e., those without the optional knife mechanism, are also commonly used to seal incisions, for example, in transactions in which the surgeon uses a scalpel to manually create an incision on the outside of the rows of staples Consequently, the danger of using an empty fastener applies equally to both cutting and non-cutting fasteners. The surgical fastening apparatus mentioned above do not possess means for preventing the problem of reactuation of an apparatus which is empty of staples.
To eliminate these dangers it is beneficial to have a locking mechanism which will allow a single use, but which will prevent the surgical stapler from being inadvertently fired more than once.
SUMMARY OF THE INVENTION
Accordingly, it is one object of the present invention to provide a surgical fastening apparatus.
It is another object of the present invention to provide an improved surgical fastening apparatus having a locking mechanism for preventing reactuation of the apparatus.
These and further objects are achieved herein by providing a surgical fastening apparatus including a single use locking mechanism to prevent reactuation of the surgical fastening apparatus, said surgical fastening apparatus comprising:
(a) a frame;
(b) a stationary carrier receivable into said frame;
(c) a pusher assembly slidably mounted within said stationary carrier, said pusher assembly comprising at least one cam bar, a cam bar retainer for mounting the cam bar, said cam bar retainer having a locking notch, a thrust knob attached to the cam bar retainer and optionally a knife mounted to the cam bar retainer;
(d) a resilient locking clip fixed to the stationary carrier and having a hook, said locking clip being adapted to be resiliently urged from a first position wherein said hook is non-engagable with said locking notch, to a second position wherein said hook is engagable with said locking notch; and,
(e) a blocking means, adapted to be movable from a location wherein said blocking means holds said locking clip in said non-engagable first position to a location wherein said blocking means does not hold said locking clip in the non-engagable first position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exploded side view of the surgical fastener;
FIG. 2 illustrates the placement of the removable carrier within the surgical fastener;
FIG. 3 illustrates the manual operation of the surgical fastener;
FIG. 4 illustrates a cut-away perspective view of the locking mechanism in the locked position;
FIG. 5 illustrates a side view of the lock mechanism in the unlocked position. The arm and thrust knob are not shown; and,
FIG. 6 illustrates a cut-away perspective view of the locking mechanism. The cam bars, knife, and sliding chock are not shown.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1, 2 and 3 illustrate a surgical fastening apparatus for placing gastrointestinal anastomoses. Surgical fastening apparatus 100 is composed of a cartridge half of a frame 101 having a cartridge fork 102, an anvil half of a frame 103 having an anvil fork 104 and a pivotable large handle 107, and a disposable loading unit 105 comprising a cartridge assembly 106 (which carries the surgical staples), a stationary carrier 120, and a slidable pusher assembly 108 which includes cam bars 150a, 150b, cam bar retainer 110, optional knife 160, chock 130 and thrust knob 140. The disposable loading unit 105 is loaded into the cartridge half of the frame 101 as shown in FIG. 2, the instrument is assembled, and actuated as shown in FIG. 3 (body tissue to be fastened is not illustrated).
FIGS. 4, 5 and 6 illustrate a single use locking mechanism to prevent reactuation of the surgical stapling apparatus. Stationary carrier 120 is an elongated metal piece having a substantially U-shaped cross section with a base 122 and sidewalls 121a and 121b. Stationary carrier 120 is adapted to fit into a surgical stapler as shown in FIGS. 1, 2 and 3. At its proximal end, stationary carrier 120 has a backflap 123 to prevent the sliding pusher assembly from exiting the instrument. Base 122 has an opening 124 of generally U-shape. Tongue shaped resilient spring clip 128 is attached at its proximal end to base 122 and defines the inner perimeter of the opening 124. Clip 128 is optimally an integral part of the carrier 120. Hook 129 at the distal end of resilient clip 128 curves back in the proximal direction. Optimally, clip 128 is a planar strip which is resiliently bendable in a direction transverse to its plane. Stationary carrier 120 also has a catch plate 125 with guide slope 127 and, as shown in FIG. 5, an aperture 126 for engaging circular detent 116 as explained below.
The surgical fastening apparatus of the present invention also comprises a slidable pusher assembly located within the stationary carrier. The slidable pusher assembly is composed of one or more cam bars 150a, 150b, optionally a knife 160, a cam bar (and knife) retainer 110, and a thrust knob 140. When the instrument is actuated the cam bars will be longitudinally moved through a cartridge assembly, thereby firing the staples.
Cam bar retainer 110 is a solid member, preferably constructed of a strong polymeric resin, which serves as a mounting for the cam bars 150a and 150b and knife 160. Slot 112a in the cam bar retainer receives cam bar 150a, slot 112b receives cam bar 150b, and slot 113 receives knife 160. Cam bar retainer 110 has a horizontal locking notch 111 at its distal end for engaging hook 129. Large and small shoulders, 118 and 117 ride longitudinally within stationary carrier 120. Front face 135 of large shoulder 118 acts as a stop when cam bar retainer 110 reaches the proximal end of cartridge 106. Cam bar retainer 110 has a shelf 114 for engaging the overhang 131 of the chock 130. Backslope 115 enables the cam bar retainer to be easily retracted to the original position in the proximal end of stationary carrier 120. Cam bar retainer 110 also has a circular detent 116 which is received into aperture 126 of catch plate 125. The detent keeps the cam bar retainer 110 secured from accidental firing during shipping and handling. However, the operating surgeon can easily override it manually when pushing on the thrust knob. Arm 119 extends outward from the cam bar retainer 110 and is optimally an integral piece thereof. Thrust knob 140 is attached to arm 119 and provides a means for manually actuating the slidable cam assembly.
Chock 130 provides a blocking means to block or bar the locking clip 128 from resiliently bending into a position wherein hook 129 can engage locking notch 111 of the cam bar retainer 110. Chock 130 is slidably mounted on cam bar 150b, and has two depending legs 132a and 132b, which define a slot 133 for riding on the cam bar 150b. Chock 130 also has an overhang 131 adapted to engage shelf 114 of the cam bar retainer 110. The outward facing surface of chock 130 contacts the inner surface of sidewall 121b, particularly along the outwardly facing surface of depending leg 132b.
The single use locking mechanism is initially in the position as shown in FIG. 5. (The arm and thrust knob are not shown.) The freely slidable chock 130 rests on cam member 150b and is located under the hook 129 of resilient clip 128. In this position hook 129 cannot engage notch 111 of the cam bar retainer 110 because the chock holds the locking clip 128 in a position where said hook 129 is not longitudinally aligned with the notch 111. To actuate the instrument, the surgeon presses on the thrust knob 40 with sufficient force to override the cooperation between detent 116 and catch plate 125, e.g., by shearing off detent 116 or deflecting catch plate 125 away from detent 116. The pusher assembly 108 slides distally in carrier 120 whereupon cam bar retainer 110 engages chock 130 and pushes it to the distal end of the carrier 120. A viscous lubricant on the inside surface of sidewalls 121a and 121b facilitates the sliding movement. The chock scrapes most of the lubricant off the inner surface of side wall 121b as it passes, thereby increasing the frictional resistance to returning to its original position. When the staples are fired the thrust knob 140 is pulled proximally and the cam bar retainer is drawn back into the initial position. Rear sloping surface 115 enables it to pass the resilient clip. The chock 130 is not drawn all the way back, however, in part because of the increased friction with side wall 121b, and chock 130 remains in a subsequent location where it no longer abuts locking clip 128. After cam bar retainer 110 moves proximally past clip 128, clip 128 resiliently springs into a position in which hook 129 is engagable with notch 111. If the surgeon inadvertently attempts to reactuate the instrument, the hook 129 and notch 111 will engage and the cam bar retainer 110 will lock, as shown in FIG. 4.
The loading unit 105 containing the stationary carrier 20, cartridge assembly 106, and pusher assembly 108, is optimally disposable. After using one loading unit, the surgeon may replace it with a new loading unit. The two part frame may be reused. However, it is also within the scope of this invention to have an entirely disposable apparatus in which the frame is not meant to be reused.
Generally the stationary carrier is made of metal such as stainless steel. The cam bars and knife are also preferably of stainless steel construction. The cam bar retainer, chock, arm and thrust knob may be made of any suitable high strength polymeric resin such as polycarbonate.
While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto.
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An improved surgical stapling apparatus containing a locking mechanism to prevent reactuation of the apparatus, the locking mechanism comprising a resilient clip having a hook which is engagable with a locking notch on the cam bar retainer. The resilient clip is initially held in a non-engagable position by means of a movable chock. When the stapler is actuated for the first time, the cam bar retainer pushes the chock into a subsequent position where the chock no longer blocks the resilient clip. The resilient clip then moves to a position where the hook is engagable with the locking notch. Once the cam bar retainer is retracted it can no longer be reactuated.
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Safety syringes for minimizing accidental contact with users are generally discussed herein with particular discussions extended to safety syringes having manual and automatic retractable carriages.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to German Utility Model DE 20 303 231 U1, filed on Feb. 27, 2003, the contents of which are expressly incorporated herein by reference.
BACKGROUND
Syringes are used for injecting fluids and for withdrawing fluids from fluid carrying sources. In an effort to reduce the transfer of communicable diseases, safety features were added to commercially available syringes to minimize accidental contact or sticking with used needle tips.
Principally among these safety features are tip protectors and syringes with retractable carriages. Broadly speaking, in the tip protector technology, a protective element is mounted over a needle and configured to cover the needle tip of the needle subsequent to an injection to block the needle tip. The protective element may be activated manually to cover the needle tip or automatically by way of releasing a spring to then push the protective element over the needle tip.
In the retractable carriage technology, the syringe is fitted with a movable carriage at a distal end of the syringe barrel. The carriage may incorporate a fixed needle or a Luer tip for mounting a needle hub with a needle. After an injection, the carriage can be retracted into the interior cavity of the syringe barrel along with the needle to prevent needle stick. More particularly, following an injection, the carriage is typically engaged by a plunger and retracted into the interior cavity of the barrel by pulling onto the plunger in the opposite or proximal direction. Alternatively, the carriage is disengaged from the barrel by the plunger and a spring automatically retracts the carriage into the interior cavity of the barrel.
Although the prior art safety features for syringes are useful, the safety syringes described elsewhere herein are better alternatives. Among other things, the prior art safety devices have shortcomings in that the air cannot be completely expelled from the syringe barrel prior to aspirating fluid without triggering the safety mechanism by the plunger. This premature triggering, when attempting to fill the device, makes the prior art syringe ineffective and frustrates the health care worker trying to use it.
SUMMARY
The present invention may be implemented by providing a syringe comprising a barrel comprising a gripping flange at a proximal end, an opening at a distal end for receiving a needle hub, a wall structure comprising an exterior surface and an interior surface defining an interior cavity, and a pair of female detents on the interior surface positioned closer to the distal end than the proximal end with a plunger disposed in the interior cavity of the barrel, the plunger comprising a push flange at a proximal end, and a tip holder comprising a plunger tip mounted thereon proximate a distal end; wherein said plunger tip comprises a plunger tip distal end surface spaced apart from the push flange by a first distance. A carriage is incorporated comprising a Luer tip, a passage, a pair of legs extending away from the Luer tip with each leg comprising a male detent wherein the carriage is removably secured to the barrel by engaging the male detents on the carriage with the female detents on the barrel. Finally, the plunger may comprise three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the carriage; a second plunger position in which the plunger tip or tip holder holding the plunger tip contacts the carriage; and a third plunger position in which the push flange on the plunger moves a distal direction relative to the plunger tip distal end surface such that the push flange is now spaced apart from the plunger tip distal end surface by a second distance, which is less than the first distance.
In another aspect of the present invention, a syringe comprising a barrel comprising a gripping flange at a proximal end, an opening at a distal end for receiving a needle hub, a wall structure comprising an exterior surface and an interior surface defining an interior cavity, and a pair of hinged hooks proximate the opening may be used with a plunger disposed in the interior cavity of the barrel, the plunger comprising a push flange at a proximal end, and a tip holder comprising a plunger tip mounted thereon proximate a distal end; wherein said plunger tip comprises a plunger tip distal end surface spaced apart from the push flange by a first distance. A carriage may be incorporated comprising a Luer tip, a passage, two wells, and two projections located inside the passage with at least one of the projections being positioned subjacent the wells wherein the carriage is removably secured to the barrel by engaging the hinged hooks on the barrel with the wells. Finally, the plunger may comprise three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the carriage; a second plunger position in which the plunger tip or tip holder holding the plunger tip contacts the carriage; and a third plunger position in which the push flange on the plunger moves a distal direction relative to the plunger tip distal end surface such that the push flange is now spaced apart from the plunger tip distal end surface by a second distance, which is less than the first distance.
In still yet another aspect of the present invention, there is provided a syringe comprising a barrel comprising a gripping flange at a proximal end, an inward projection at a distal end comprising an opening and defining a first internal shoulder, a wall structure comprising an exterior surface and an interior surface defining an interior cavity, and a second internal shoulder positioned closer to the opening at the distal end than the gripping flange at the proximal end for use with a plunger comprising a tubular body having an interior cavity disposed in the interior cavity of the barrel, a push flange at a proximal end, and a tip holder comprising a push end having a plunger tip mounted thereon abutting a shoulder on the tubular body. A carriage may be incorporated comprising an elongated body having a spring located thereon, a base extending from the elongated body, a shoulder positioned between the elongated body and the base, and a passage comprising a needle attached thereto wherein the spring is compressed by the first internal shoulder of the barrel and the shoulder on the carriage and the carriage is removably secured to the barrel by wedging a resilient holding tire in between the base of the carriage and the interior surface of the barrel. Finally, the plunger may comprise three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the carriage; a second plunger position in which the plunger tip simultaneously contacts the shoulder on the plunger and the second internal shoulder on the barrel before the holding tire is substantially pushed off of the base of the carriage; and a third plunger position in which the push end on the plunger pushes the holding tire distally off of the base of the carriage.
In yet another aspect of the present invention, there is provided a syringe comprising a barrel comprising a gripping flange at a proximal end, an inward projection at a distal end comprising an opening and defining a first internal shoulder, a wall structure comprising an exterior surface and an interior surface defining an interior cavity, and a second internal shoulder positioned closer to the opening at the distal end than the gripping flange at the proximal end for use with a plunger comprising a tubular body having an interior cavity disposed in the interior cavity of the barrel, a push flange at a proximal end, a tip holder comprising a push end having a plunger tip mounted thereon abutting a shoulder on the tubular body, and a radially outwardly projection located distal of the shoulder and positioned inside and abutting a surface of an interior bore of the plunger tip. A carriage may be incorporated comprising an elongated body having a spring located thereon, a base extending from the elongated body, a shoulder positioned between the elongated body and the base, and a passage comprising a needle attached thereto wherein the spring is compressed by the first internal shoulder of the barrel and the shoulder on the carriage and the carriage is removably secured to the barrel by wedging a resilient holding tire in between the base of the carriage and the interior surface of the barrel. Finally, the plunger may comprise three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the carriage; a second plunger position in which the plunger tip contacts the second internal shoulder of the barrel and the radially outwardly projection on the plunger contacts a proximal surface on the plunger tip; and a third plunger position in which the push end on the plunger pushes the holding tire distally off of the base of the carriage.
In still yet another aspect of the present invention, there is provided a syringe comprising a barrel comprising a gripping flange at a proximal end, a Luer tip at a distal end, and an end surface defining a shoulder having an opening in communication with the Luer tip, and a wall structure comprising an exterior surface and an interior surface defining an interior cavity for use with a plunger disposed in the interior cavity of the barrel, the plunger comprising a push flange at a proximal end, a tip holder comprising a plunger tip mounted thereon proximate a distal end, and a central tubular body comprising a bore; wherein said plunger tip comprises a plunger tip distal end surface spaced apart from the push flange by a first distance and a needle hub comprising a passage defining a lumen mounted to the Luer tip, a well section having a thin-walled surface forming part of the passage, a needle removably attached to the passage via a detent engagement, and a spring compressed inside the passage. Finally, the plunger may comprise three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the shoulder on the barrel; a second plunger position in which the plunger tip contacts the shoulder; and a third plunger position in which the push flange on the plunger moves a distal direction relative to the plunger tip distal end surface such that the push flange is now spaced apart from the plunger tip distal end surface by a second distance, which is less than the first distance.
Yet in another aspect of the present invention, there is provided a syringe comprising a barrel comprising a gripping flange at a proximal end, a Luer tip at a distal end, an end surface defining a shoulder, and a wall structure comprising an exterior surface and an interior surface defining an interior cavity capable of receiving a retracted needle; and a plunger disposed in the interior cavity of the barrel, the plunger comprising a push flange at a proximal end and a tip holder comprising a tip flange and a plunger tip mounted thereon proximate a distal end; said plunger tip comprising a plunger tip distal end surface spaced apart from the push flange by a first distance and a bore having an annular ring comprising a distal end surface and a proximal end surface; the tip flange being disposed in an interior cavity of the bore of the plunger tip. The plunger in accordance with this aspect may comprise four plunger positions including a first plunger position in which the plunger retracts proximally to aspirate a fluid and in which the tip flange on the plunger contacts the distal end surface of the annular ring as the plunger is retracted proximally; a second plunger position in which the plunger moves distally and the plunger tip positioned on the plunger is spaced apart from the shoulder on the barrel; a third plunger position in which the plunger tip contacts the shoulder; and a fourth plunger position in which the push flange on the plunger moves a distal direction relative to the plunger tip distal end surface such that the push flange is now spaced apart from the plunger tip distal end surface by a second distance, which is less than the first distance, and in which the tip flange located in the bore of the plunger tip no longer contacts the distal end surface of the annular ring.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become appreciated as the same become better understood with reference to the specification, claims and appended drawings wherein:
FIG. 1 is a semi-schematic cross-sectional view of a syringe with a manual retractable carriage provided in accordance with aspects of the present invention;
FIG. 2 is a semi-schematic cross-sectional view of the syringe of FIG. 1 with the carriage engaged by a plunger for retracting into the barrel of the syringe;
FIG. 2 a is a semi-schematic cross-sectional view of an alternative plunger tip provided in accordance with aspects of the present invention;
FIG. 2 b is a semi-schematic exemplary plan view of two alignment plates incorporated by the syringe of FIG. 1 ;
FIG. 3 is a semi-schematic cross-sectional view of an alternative syringe with a manual retractable carriage provided in accordance with aspects of the present invention;
FIG. 4 is a semi-schematic cross-sectional view of the syringe of FIG. 3 with the carriage engaged by a plunger for retracting into the barrel of the syringe;
FIG. 5 is a semi-schematic cross-sectional view of another alternative syringe with a manual retractable carriage provided in accordance with aspects of the present invention;
FIG. 6 is a semi-schematic cross-sectional view of the syringe of FIG. 5 with the carriage engaged by a plunger for retracting into the barrel of the syringe;
FIG. 7 is a semi-schematic cross-sectional view of yet another alternative syringe with a manual retractable carriage provided in accordance with aspects of the present invention;
FIG. 8 is a semi-schematic cross-sectional view of the syringe of FIG. 7 with the carriage engaged by a plunger for retracting into the barrel of the syringe;
FIG. 9 is a semi-schematic cross-sectional view of yet another alternative syringe with a manual retractable carriage provided in accordance with aspects of the present invention;
FIG. 10 is a semi-schematic cross-sectional view of the syringe of FIG. 9 with the carriage engaged by a plunger for retracting into the barrel of the syringe;
FIG. 11 is a semi-schematic cross-sectional view of a syringe with a spring loaded carriage provided in accordance with aspects of the present invention;
FIG. 12 is a semi-schematic cross-sectional view of the syringe of FIG. 11 with the carriage disengaged and ready for retraction;
FIG. 13 is a semi-schematic cross-sectional view of the syringe of FIG. 11 with the carriage retracted inside the barrel;
FIG. 14 is a semi-schematic cross-sectional view of an alternative syringe with a spring loaded carriage provided in accordance with aspects of the present invention;
FIG. 14A is a semi-schematic cross-sectional view of the syringe of FiG. 14 in a plunger first position.
FIG. 15 is a semi-schematic cross-section view of the syringe of FIG. 14 with the carriage disengaged and ready for retraction;
FIG. 16 is a semi-schematic cross-sectional view of another alternative syringe with a spring loaded carriage provided in accordance with aspects of the present invention;
FIG. 17 is a semi-schematic cross-sectional view of the syringe of FIG. 16 with the carriage disengaged and ready for retraction;
FIG. 18 is a semi-schematic partial cross-sectional view of a syringe with a needle hub having a spring loaded retractable needle provided in accordance with aspects of the present invention;
FIG. 19 is a semi-schematic partial enlarged view of the needle hub of FIG. 18 ;
FIG. 20 is a semi-schematic partial cross-sectional view of the syringe of FIG. 18 with the needle retracted partially into the barrel;
FIG. 21 is a semi-schematic partial cross-sectional view of an alternative syringe with a needle hub having a spring loaded retractable needle provided in accordance with aspects of the present invention;
FIG. 22 is a semi-schematic partial cross-sectional view of another alternative syringe with a needle hub having a spring loaded retractable needle provided in accordance with aspects of the present invention; and
FIG. 23 is a semi-schematic partial enlarged view of an alternative needle hub having a spring loaded retractable needle provided in accordance with aspects of the present invention.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of safety syringes provided in accordance with practice of the present invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the features and the steps for constructing and using the safety syringes of the present invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. Also, as denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features.
Referring now to FIG. 1 , an exemplary syringe 10 with a retractable carriage 12 provided in accordance with aspects of the present invention is shown. In one exemplary embodiment, the syringe 10 , which may be of any standard sizes such as 5 ml or 10 ml, comprises a barrel 14 , a proximal end 16 with a grip flange 18 , and a distal end 20 with an opening 22 for receiving a standard needle hub having a needle attached thereto (not shown).
The barrel 14 defines a wall surface which has an exterior surface 24 and an interior surface 26 , which defines an interior cavity 28 . Positioned in the interior cavity 28 are the plunger 30 , which has a push flange 32 on one end and a plunger tip or seal 34 on another end, and the carriage 12 . In one exemplary embodiment, the carriage 12 comprises a male Luer tip 36 , a sealing ring 38 , and a pair of proximally extending arms 40 a , 40 b . The sealing ring 38 is configured to seal against the interior surface 26 of the barrel 14 and in combination with a portion of the interior surface 26 of the barrel 14 defines a volume enclosure, which is variable depending on the position of the plunger 30 and plunger tip 34 relative to the barrel. A lumen 42 is defined through the axial center of the carriage 12 for fluid communication between the interior cavity 28 of the syringe and exteriorly of the barrel 14 variable volume enclosure. The plunger tip 34 is dynamically sealed against the interior surface 26 of the barrier by well known methods.
The proximally extending arms 40 a , 40 b are cantilevered to the base of the sealing ring 38 by a pair of integrally molded bridges 42 a , 42 b ( FIG. 2 ). The cantilevered configuration permit the arms 40 a , 40 b to flex radially inwardly in the direction of the longitudinal axis defined by the lengthwise central axis of the barrel for reasons discussed further below. Just proximal of the bridges 42 a , 42 b are the raised ridges 44 a , 44 b and the male detents 46 a , 46 b , which matingly engage with the female detents 48 a , 48 b formed in the interior surface 26 of the barrel 14 when the carriage 12 is in the ready to use position. Two actuated ramps 50 a , 50 b are positioned further proximal of the male detents 46 a , 46 b . In one exemplary embodiment, the actuated ramps 50 a , 50 b incorporate diagonal faces for imparting a pair of component forces to the arms 40 a , 40 b when pushed by the plunger 30 to flex the arms 40 a , 40 b radially inwardly, as further discussed below. The actuated ramps 50 a , 50 b terminate in a hook-like configuration for engaging with the shroud 62 ( FIG. 1 ). The barrel 14 , plunger 30 , carriage 12 , and plunger tip 34 may be made from known materials currently used in the art.
In one exemplary embodiment, the barrel 14 comprises two tapered sections. A first tapered section 52 is formed in the interior cavity 28 of the barrel and acts as a shoulder to stop the distal or forward advancement of the plunger tip 34 . The second tapered section 54 is formed on the exterior surface 24 of the barrel 14 for aesthetic appeal that may otherwise be eliminated. Alternatively, the tapered sections 52 , 54 may be squared, or may incorporate a combination of a squared finish and a tapered finish. The barrel is preferably transparent or semi-transparent and may include indicia such as labeling, markings, or other features for references.
In one exemplary embodiment, the plunger 30 incorporates a pair of elongated plates 55 a , 55 b having a plus (“+”)-shaped cross-section. One or more push plates 56 may be formed on plunger 30 for reinforcement. A distally projecting post or tip holder 58 is positioned distal of the one or more push plates 56 for positioning the plunger tip 34 thereon. A plunger disc 60 is formed on the distally projecting post 58 and is preferably spaced from the most distal push plate 56 by a gap, which should be of sufficient width for accommodating a portion of the plunger tip 34 , as further discussed below. A generally cylindrical shroud 62 is positioned distal of the plunger disc 60 having a pusher end 64 ( FIG. 2 ) and a pair of receiving slots 66 . In one exemplary embodiment, the pusher end 64 and the plunger disc 60 each comprises a tapered surface for reasons further discussed below. The receiving slots 66 should have a dimension sufficient to receive the hook-like ends of the actuated ramps 50 a , 50 b.
The shroud 62 comprises a distal end surface 67 having a pair of openings 69 for receiving the proximally extending arms 40 a , 40 b of the carriage 12 . The plunger tip 34 comprises a bore 68 for receiving the shroud 62 . In one exemplary embodiment, the bore 68 of the plunger tip comprises a first diameter section 70 , a second diameter section 72 , and a third diameter section 74 ( FIG. 2 ). However, the internal bore 68 can have a same diameter by modifying the dimensions of the post 58 , shroud 62 , and/or carriage 12 . An inwardly extending ring 76 is formed on the proximal end of the plunger tip 34 and sized to form a size-on-size friction fit with the distally projecting post 58 of the plunger 30 . A second inwardly extending ring 78 spaced from the first inwardly extending ring 76 is positioned at the transition between the second diameter section 72 and the third diameter section 74 of the plunger tip. The space or gap 80 between the first 76 and second 78 inwardly extending rings functions as an activation gap and is configured to receive the plunger disc 60 when the plunger 30 is advanced distally to activate or retract the carriage 12 , as further discussed below.
In an alternative plunger tip 34 ′ embodiment ( FIG. 2 b ), the second inwardly extending ring 78 may be omitted and the proximal end 61 of shroud 62 ′ extended or moved further proximal to be adjacent the distal side of extending ring 76 ′. This eliminates the need for a gap 80 and simplifies the form of plunger tip 34 ′. The alternative plunger tip 34 ′ otherwise functions the same as the plunger tip 34 of FIGS. 1 and 2 .
To use the syringe 10 , a commercially available needle attached to a needle hub (not shown) is first mounted onto the Luer tip 36 . Because the syringe 10 has a Luer tip 36 and not a permanently attached needle on the carriage 12 , different needle sizes may be mounted onto the Luer tip for aspirating, withdrawing a sample, or performing an injection. Preferably, if the syringe is used to withdraw a sample, the needle with the needle hub should include a tip protector or clip for covering the needle tip.
With the barrel 14 filled with a medicinal fluid, which can be any number of fluids, to a desired volume and the needle injected into a subject, the plunger 30 is advanced distally with a distally directed force F D in the direction of the needle to discharge the fluid. The injection is completed when the plunger tip 34 contacts the shoulder or first tapered section 52 of the barrel 14 . At this point, preferably the needle is withdrawn from the subject by pulling on the plunger 30 via the push flange 32 while pushing the barrel 14 distally against the patient's skin. The needle and carriage 12 retraction into the barrel are simultaneously accomplished as described in detail below. Alternatively, the needle can be withdrawn from the patient prior to retracting the needle into the barrel 14 .
To retract the carriage 12 with the needle still mounted thereto, the plunger 30 is further advanced distally with an activated force F A sufficient to bend the proximally extending arms 40 a , 40 b inwardly at the bridges 42 a , 42 b , which act as fulcrum points. In one exemplary embodiment, the activated force F A is greater than the distally advancing force F D so that a user in using the syringe 10 can feel a clear delineation between injecting a fluid and withdrawing the carriage 12 .
The bending of the arms 40 a , 40 b occur when the pusher end 64 of the shroud 62 , which preferably comprises a tapered face, contacts the actuated ramps 50 a , 50 b of the arms 40 a , 40 b and impart a pair of component forces. The arms 40 a , 40 b bend radially inwardly and the male detents 46 a , 46 b separate from the female detents 48 a , 48 b as the plunger 30 advances distally under an actuated force F A . The arms continue to bend as until the hook-like ends of the actuated ramps 50 a , 50 b latch with the receiving slots 66 a , 66 b located in of the shroud 62 . When the activated force F A is no longer applied, the arms 40 a , 40 b , due to their resiliency, snap radially outwardly a small radial distance to securely engage with the slots 66 a , 66 b ( FIG. 2 ).
During the activation step, the plunger disc 60 pushes against the inwardly extending ring 76 of the plunger tip 34 until the ring 76 , due to its resiliency, pops over the disc 60 so that the disc can then move into the activated space 80 . As readily apparent, subsequent to the plunger tip 34 abutting the shoulder 52 of the barrel and stop moving, the plunger 30 may still move distally relative to the plunger tip to disengage the carriage 12 from the barrel 14 . Unrestrained, the carriage 12 and needle (not shown) can then be retracted into the interior cavity 28 of the barrel 14 by grasping and pulling on the push flange 32 proximally to retract the needle into the barrel 14 .
To prevent retracting the carriage 12 too far into the barrel 14 and possibly dislodge the carriage 12 from the barrel 14 and to also prevent the needle from protruding back out the distal end 20 of the barrel, in one exemplary embodiment, a stop ring 82 ( FIG. 2 ), which may comprise an annular projection on the interior surface 26 of the barrel near the grip flange 18 , may be incorporated to hold the plunger 30 in the completely retracted position. The plunger 30 may include a notch 84 along each edge of the elongated plates 55 a , 55 b to provide a breaking point for breaking off the plunger and avoiding accidentally pushing the needle distally into an unprotected position. Once the carriage 12 is retracted into the barrel and the plunger 30 broken off, the syringe may be safely disposed of per standard protocols.
For aligning the hooks on the actuated ramps 50 a , 50 b of the carriage 12 with the receiving slots 66 a , 66 b located on the shroud 62 of the plunger 30 , alignment plates 86 a , 86 b may be incorporated at the proximal end 16 of the barrel 14 . The alignment plates 86 a , 86 b may be integrally molded with the push flange 18 via living hinges 88 and then glued, welded, or engaged to the push flange 18 by detents. Alternatively, the alignment plates 86 a , 86 b may be separately attached to the push flange 18 via adhesive, welding, or detents without the living hinges 88 .
Referring to FIG. 2 a , which is an exemplary plan view of the alignment plates 86 a , 86 b , each alignment plate 86 a or 86 b comprises a gripping portion 90 and a semi-circular portion 92 comprising a slot 94 and a part of a slot 96 . The two alignment plates 86 a , 86 b come together at a parting line and the two part slots 96 on each alignment plate makes a whole slot. The two whole slots 94 are sized to receive one rectangular plate 55 a of the plunger 30 while the partial slots 96 together receive the other rectangular plate 55 b of the plunger 30 . Cooperation between the alignment plates 86 a , 86 b and the rectangular plates 55 a , 55 b prevents the plunger 30 from angularly rotating and misaligning the hooks on the actuated ramps 50 a , 50 b with the receiving slots 66 a , 66 b located on the shroud 62 .
Turning now to FIG. 3 , an alternative manual retractable syringe 98 provided in accordance with aspects of the present invention is shown. The syringe 98 has features that are similar with features described above for the syringe 10 shown with reference to FIGS. 1-2A with the exception of the plunger tip 100 and the manner in which the plunger tip engages and interacts with the plunger 30 . In the present syringe 98 embodiment, the shroud 62 incorporates two openings 102 a , 102 b at the distal end surface 67 for receiving the proximally extending arms 40 a , 40 b . The plunger tip 100 comprises a bore 101 having a substantially uniform inside diameter for receiving the shroud 62 . An inwardly extending ring 104 is incorporated at the proximal end of the plunger tip 100 and sized to form a size-on-size friction fit with the distally projecting post 58 of the plunger 30 . In the ready to use configuration of FIG. 3 , the inwardly extending ring 104 abuts the plunger disc 106 located on the post 58 of the plunger 30 , which in the present embodiment does not incorporate a tapered face. A shroud 62 comprising a pair of receiving slots 66 and pusher end 64 is disposed inside the bore 101 of the plunger tip 100 for engaging with the hooks on the carriage 12 and retracting the same into the barrel 14 .
The syringe 98 may be used and the carriage 12 may be retracted into the barrel 14 in the same manner as described above with reference to the syringe 10 of FIGS. 1 and 2 . More particularly, following an injection, the distal end of the plunger tip 100 abuts the barrel shoulder 52 and the proximally extending arms 40 a , 40 b of the carriage 12 project into the openings 69 of the distal end surface 67 of the shroud 62 . To retract the carriage 12 , an activated force F A is then applied on the plunger 30 to further advance the plunger distally relative to the distal end of the plunger tip 100 . This activated force F A causes the pusher end 64 of the shroud 62 to exert a pair of component forces to the actuated ramps 50 a , 50 b , which then bends the proximally extending arms 40 a , 40 b radially inwardly. At the same time, the plunger disc 106 pushes against the inwardly extending ring 104 and compresses the plunger tip 100 ( FIG. 4 ).
The carriage 12 may be withdrawn proximally into the barrel 14 when the male detents 46 a , 46 b disengage from the female detents 48 a , 48 b and the hooks on the end of the arms 40 a , 40 b engage the receiving slots 66 located on the shroud 62 . During the retraction procedure, the plunger tip 100 will expand in the distal direction until it touches or reaches near the proximal edge 108 of the side ridges 44 a , 44 b of the carriage 12 .
FIG. 5 shows another alternative retractable syringe 110 provided in accordance with aspects of the present invention. The syringe 110 is similar to the syringes of FIGS. 1-4 with the exception the carriage 112 and the manner in which it engages the barrel 114 and is retracted by the plunger 116 . In one exemplary embodiment, the carriage 112 incorporates a pair of actuated pistons 118 a , 118 b formed in two wells 120 located on the carriage. The carriage 112 further comprises a female lock 122 around a Luer tip 36 , and a hub. 124 proximal of the actuated pistons 11 a , 118 b . The hub 124 incorporates a flange 126 for abutting against the shoulder 128 located on the barrel 114 to axially align the carriage 112 relative to the barrel 114 during engagement of the carriage 112 to the barrel 114 . The hub 124 includes a proximal surface 127 having a configuration to accommodate the contour of the distal end surface 130 of the plunger tip 132 .
The carriage 112 comprises a bore 133 which defines a lumen 134 for fluid communication between the variable interior cavity 28 of the barrel 114 and the needle (not shown) which may be mounted to the syringe by the way of mounting a needle hub to the Luer tip 36 . In one exemplary embodiment, the bore 133 incorporates two inward projections for interacting with the plunger 116 . The first projection 136 is located near the opening of the Luer tip 36 and has a tapered or sloped surface on a proximal side. On the edge opposite the sloped surface, the first projection 136 preferably comprises a square finish, for reasons further discussed below. The second projection 138 is formed subjacent the two actuated pistons 118 a , 118 b . To fixedly secure the carriage 112 to the barrel 114 , the barrel incorporates a pair of hinged hooks 140 at the distal end of the barrel. The hinge hooks 140 engage an edge of the wells 120 located on the carriage 112 to lock the carriage to the barrel. The hinge hooks 140 can be integrally molded on the carriage 112 .
In one exemplary embodiment, the plunger tip 132 incorporates a bore for receiving the extension pin or distally projected post 142 of the plunger 116 , an internal space or cavity 145 , and a pair of extension legs 144 a , 144 b for setting a gap between certain parts of the plunger 116 and of the plunger tip 132 . A gap or a space 146 located in between the extension legs 144 a , 144 b are configured to receive a drum 148 located at the base of the extension pin 142 . The gap or space 146 should have sufficient depth to receive the drum 148 and not delimit or restrict the hooks on the plunger 116 from grabbing the first projection 136 located in the Luer tip 36 , as further discussed below. The plunger 116 also comprises a flange 147 set in the internal space 145 of plunger tip 132 , and in one exemplary embodiment, comprises a tapered face on its distal side to facilitate assembly over the tip holder. Flange 147 secures plunger tip 132 to the plunger 116 during aspiration of a fluid. The internal space 145 should be sufficiently long to allow the flange 147 to move from a proximal end within the internal space 145 to a distal end during activation so as not to delimit or hinder the hooks 152 from grabbing first projection 136 .
A hooking rod 150 comprising a pair of hooks 152 ( FIG. 6 ) extends from the distal end of the extension pin 142 for hooking engagement with the first projection 136 located in the bore of the Luer tip 36 . The hooks 152 are configured to deflect when moved distally past a reduced diameter created in the bore of the Luer tip by the first projection 136 to grab the square face of the first projection 136 in a detent configuration.
To retract the carriage 112 into the interior cavity 28 of the barrel 114 , the plunger 116 is first advanced distally with a distally directed force F D until the distal end surface 130 of the plunger tip 132 contacts the proximate surface 127 of the hub 124 of the carriage 112 . In this position, the distal end of the extension pin 142 should reside just proximal of the second projection 138 located subjacent the actuated pistons 118 a , 118 b ( FIG. 5 ). As a distally actuated force F A force is then applied to the plunger 116 , the force causes the extension legs 144 a , 144 b to bend outwardly, which then moves the extension pin 142 past the second projection 138 to push the actuated pistons 118 a , 118 b radially outwardly. Concurrently therewith, the actuated pistons 118 a , 118 b push the hinged hooks 140 on the barrel to unlock the hinged hooks 140 from the wells 120 . Also at the same time, the hooks 152 on the hooking rod 150 moves distal of the first projection 136 to then grab the projection. When the plunger is moved in the opposite proximal direction, the interaction between the hooks 152 and the first projection retracts the carriage 112 into the barrel 114 .
Although alignment plates 86 a , 86 b are not required to align parts of the plunger 116 to parts of the carriage 112 , the plates 86 a , 86 b may be included to prevent retracting the plunger 116 completely outside of the barrel 114 . Alternatively or in addition thereto, a stop ring 82 may be incorporated near the proximal end of the barrel to engage with the proximal most push plate 56 on the plunger 116 to prevent proximal movement of the plunger. The plunger can then be broken off at the notches 84 , as previously described.
In another alternative embodiment (not shown), the hooking rod 150 and hooks 152 are eliminated from the end of the extension pin 142 of the syringe of FIG. 5 . A second set of actuated pins proximal of the existing actuated pins 118 a , 118 b on the carriage 112 are added, which are to be actuated and engaged by a pair of projections or ramps located on the extension pin 142 . In this alternative embodiment, the extension pin 142 would actuate the first set of actuated pins 118 a , 118 b to disengage the carriage 112 from the barrel 114 and the two projections or ramps on the extension pin 142 would latch or engage with the second set of actuated pins to grab the carriage 112 . Once the plunger is retracted, the cooperation between the ramps and the second set of activated pins retract the carriage proximally into the barrel. In this embodiment, the diameter of the extension pin proximal of the two projections or ramps (i.e., the base of the extension pin) should have the same diameter as the largest cross-sectional dimension of the projections or ramps measured at their widest peaks.
FIG. 7 is another alternative retractable syringe 154 provided in accordance with aspects of the present invention. The syringe 154 is substantially similar to the syringe 110 described above with reference to FIGS. 5 and 6 with the exception of the plunger tip 156 and extension pin 158 of the plunger 160 , which are different. In the present embodiment, the extension legs 144 a , 144 b of the plunger tip are eliminated and a bore 162 incorporated with an annular ring 164 . A proximal end annular ring 166 spaced apart from the interior annular ring 164 is also incorporated. The two rings define an activation space or gap 168 for accommodating a part of the extension pin 158 , as further discussed below.
A pair of plunger discs 172 , 174 are incorporated with the base 170 of the extension pin 158 for cooperating with the plunger tip 156 . The distal most plunger disc 174 preferably comprises a tapered surface for facilitating advancing the disc past the interior annular ring 164 . In one exemplary embodiment, the proximal most plunger disc 172 incorporates a square finish for pushing the proximal annular ring 166 of the plunger tip 156 distally when a distally directed force F D is applied. However, a slight taper, of less angular offset than the distal most disc 174 , may be incorporated by the proximal most disc 172 to facilitate moving the disc 172 past the end annular ring 166 when an activated force F A is applied ( FIG. 8 ).
To retract the carriage 112 into the interior cavity 28 of the barrel 114 , the plunger 160 is first advanced distally with a distally directed force F D until the distal end surface 130 of the plunger tip 156 contacts the proximal surface 127 of the carriage 112 . In this position, the distal end of the extension pin 158 should reside just proximal of the second projection 138 located subjacent the actuated pistons 118 a , 118 b . As a distally actuated force F A force is then applied on the plunger 160 , the force causes the two plunger discs 172 , 174 to move past the two annular rings 166 , 164 positioned inside the bore 162 of the plunger tip 156 , which concurrently moves the extension pin 158 past the second projection 138 to push the actuated pistons 118 a , 118 b radially outwardly. Also concurrently therewith, the actuated pistons 118 a , 118 b push the hinged hooks 140 on the barrel 114 to unlock the hinged hooks 140 from the wells 120 . Also at the same time, the hooks 152 on the hooking rod 150 moves distal of the first projection 136 to, then grab the projection. The carriage 112 can now be retracted by pulling on the plunger 160 in the proximal direction. The plunger 160 can then be broken off as previously described.
FIG. 9 shows yet another alternative manual retract syringe 176 provided in accordance with aspects of the present invention. The syringe 176 is substantially similar to the syringes 110 , 154 described above with reference to FIGS. 5-8 with the exception of the plunger tip 178 and extension pin 183 of the plunger 180 , which are different. More particularly, the extension pin 183 in the present embodiment extends directly from the distal most push plate 56 on the plunger 180 without a base or a drum. In addition, the plunger tip 178 has a single annular end ring 182 without internal annular rings. The extension pin 183 comprises a flange 185 located just distal of the annular end ring 182 . The flange 185 is preferably tapered on its distal side to facilitate assembly through the annular end ring 182 , but flat on its proximal side to secure the plunger tip 178 on plunger 180 during aspiration of a fluid. The bore or cavity 184 inside the plunger tip 178 should be sufficiently dimension to permit flexing of the plunger tip when compressed by the plunger 180 ( FIG. 10 ).
To retract the carriage 112 into the interior cavity 28 of the barrel 114 , the plunger 180 is first advanced distally with a distally directed force F D until the distal end surface 130 of the plunger tip 178 contacts the proximal surface 127 of the carriage 112 . In this position, the distal end of the extension pin 183 should reside just proximal of the second projection 138 located subjacent the actuated pistons 118 a , 118 b . As a distally actuated force F A force is then applied on the plunger 180 , the force causes the push plate 56 to push against the annular ring 182 of the plunger tip 178 and compresses the plunger tip ( FIG. 10 ). At the same time, the extension pin 183 travels past the second projection 138 to push the actuated pistons 118 a , 118 b radially outwardly. Also, concurrently therewith, the actuated pistons 118 a , 118 b push the hinged hooks 140 on the barrel 114 to unlock the hinged hooks 140 from the wells 120 on the carriage 112 . Also at the same time, the hooks 152 on the hooking rod 150 moves distal of the first projection 136 to then grab the projection. The carriage 112 can now be retracted by pulling on the plunger in the proximal direction. The plunger can then be broken off at the notches 84 , as previously described.
Referring now to FIG. 11 , an automatic needle retract syringe 186 provided in accordance with aspects of the present invention is shown. The syringe 186 comprises a syringe barrel 188 , a plunger 190 with a plunger tip 192 , and a carriage 194 that is spring loaded with a spring 196 . The barrel 188 in the present embodiment comprises a gripping section 198 having a grip flange 18 and an enlarged barrel section 200 sized to receive a part of the push flange 202 on the plunger 190 . In one exemplary embodiment, the proximal end 204 of the enlarged barrel section 200 comprises a projection or ring for engaging with the perimeter of the push flange 202 when the push flange is pushed up against the barrel 188 to retract the needle ( FIGS. 12 and 13 ), as further discussed below. Alternatively, the diameter of the enlarged barrel section 200 could be sized to form an interference fit with the push flange 202 when the same is moved into the barrel to retract the needle.
Distally of the gripping section 198 is the variable chamber section 206 , which stores fluid to be infused or injected and varies in volume depending on the position of the plunger tip 192 relative to the barrel 188 . Distal of the variable chamber section 206 is the engagement chamber 208 . The engagement chamber 208 comprises a first engagement section 210 comprising an annular interior surface 212 that cooperates with the carriage 194 to compress a holding tire 214 , which may be made from any number of elastomeric rubber or of the same elastomer as the plunger tip 192 . Distal thereof is the second engagement section 211 . The compressed holding tire 214 acts as an anchor to hold the carriage 194 in place or position, which then allows the spring 196 to be compressed between the end wall 216 at the distal end 218 of the barrel 188 and the shoulder 220 located near the base 222 of the carriage 194 . As readily apparent, the holding tire 214 should have a compression force exerted on it by the carriage 194 and the barrel 188 sufficient to resists the spring force generated by the compressed spring 196 . Additional hold on the holding tire 214 can come from the projection 244 located at the shoulder 241 of the barrel 188 .
A passage or lumen 224 is formed at the axial center of the carriage 194 to permit fluid communication between the interior cavity of the barrel 188 and outside the barrel. In one exemplary embodiment, a needle 226 comprising a needle tip is permanently secured to the carriage 194 via gluing the same to the carriage at the glue well 228 .
In one exemplary embodiment, the plunger 190 comprises a first tubular section 230 and a second tubular section 232 , which defines an exterior shoulder 234 therebetween. The plunger tip 192 is positioned on the exterior surface of the first tubular section 230 and abuts the exterior shoulder 234 . Interiorly, a plug 236 , which can be made from an elastomer material, is compressed against the interior surface of the second tubular section 232 by its base section 238 , which is relatively larger than its frontal projection 240 . Prior to activating the spring ( FIG. 11 ), the distal end of the plug 236 , the cylindrical end of the first tubular section 230 , and the plunger tip 192 are substantially aligned so that they occupy substantially all of the head space of the variable chamber section 206 to substantially discharge all of the fluid within the barrel. To facilitate this goal, the shoulder 241 between the variable chamber section 206 and the engagement chamber 208 can be square to minimize head space. Alternatively, the plunger 192 can be shaped to occupy substantially all of the head space.
To retract the carriage 194 , the plunger 190 is first moved distally with a distally directed force F D until the distal end surface of the plunger tip 192 contacts the shoulder 241 located at the interface between the first engaging section 210 and the variable chamber 206 . At this point, the end tip or distal tip 229 of the first tubular section 230 of the plunger 190 contacts the holding tire 214 and the proximal end 231 of the carriage 194 contacts the tip of the plug 236 . When an actuated force F A is then applied on the plunger 190 , the first tubular section 230 of the plunger 190 moves over the proximal end of the carriage 194 in a telescoping fashion. At the same time, the plunger tip 212 is compressed by the exterior shoulder 234 on the plunger 190 and the shoulder 241 on the barrel 188 .
Further plunger 190 distal movement causes the tip 229 of the tubular portion 230 to move the holding tire 214 distally off the base section 222 of the carriage 194 and the base 238 of the plug 236 away from the interior surface of the first tubular section 230 . In one exemplary embodiment, the holding tire 214 and the base 238 of the plug are released simultaneously from their respective seats when the plunger 190 moves distally to retract the carriage 194 . In an alternative embodiment, the holding tire 214 moves off of its seat prior to the base 238 of the plug 236 moves off of its seat. Still alternatively, the base 238 of the plug 236 moves off of its seat prior to the holding tire 214 moves off of its seat.
Once both the holding tire 214 and the plug 236 move off of their respective seats, the spring 196 is released and launches proximally in the direction of the push flange 202 . Because they are either directly or indirectly in contact with the spring 196 , the carriage 194 , the needle 226 , and the plug 236 are also simultaneously launched distally by the spring. The spring action thus retracts the needle 226 into the interior cavity of the plunger 190 to thereby prevent accidental contact with the needle tip ( FIG. 13 ).
To further assist in securing the holding tire 214 against its seat, which is the mating surface area provided by the interior surface of the barrel and the base 222 of the carriage 194 , in one exemplary embodiment, a projection 244 is incorporated at the shoulder 241 inside surface of the barrel 188 . The raised area 244 aids in snapping the holding tire 214 in place against the spring force when the plunger is in a withdrawn position.
In one exemplary embodiment, the plunger push flange 202 is seated inside a recessed section 242 ( FIGS. 12 and 13 ) of the enlarged barrel section 200 of the barrel 188 following the retraction of the carriage. Because the push flange 202 incorporates a smooth contour, the plunger 190 is made difficult to be grasped and moved proximally. In an alternative embodiment, a detent engagement between the barrel and the push flange may be incorporated to further deter access to the used needle.
An alternative automatic needle retract syringe 246 provided in accordance with aspects of the invention is shown in FIGS. 14-15 . The syringe 246 is substantially similar to the syringe 186 described above with reference to FIGS. 11-13 with the exception of the plunger tip 248 and plunger first tubular section 230 , which are different. In the present embodiment, the plunger tip 248 incorporates a pair of extension legs 250 a , 250 b and the first tubular section 230 of the plunger 190 incorporates a flange 227 . The extension legs 250 a , 250 b establish a gap or space between the exterior shoulder 234 on the plunger 190 and the plunger tip 248 when the syringe is in a ready to use position and during an injection when a distally directed force FD is applied ( FIG. 14A ). The flange 227 of plunger 190 first tubular section 230 is positioned at the proximal end of space 251 inside the plunger tip 248 . The flange 227 secures the plunger tip 248 onto plunger 190 during aspiration of a fluid, and in one exemplary embodiment comprises a tapered face on its distal side. However, when an actuated force FA is applied on the plunger 190 , the shoulder 234 bends the extension legs 250 a , 250 b outwardly to permit further distal movement of the plunger 190 relative to the plunger tip to retract the carriage 194 ( FIG. 15 ). During activation, the flange 227 moves from a proximal position to a distal position within the space 251 ( FIG. 15 ).
In the ready to retract position ( FIG. 14 ), the plunger tip 248 , plug 236 , and first tubular section 230 of the plunger 190 should occupy substantially all of the head space of the variable volume chamber to minimize fluid waste. In this configuration, the plunger tip 248 should be in contact with the shoulder 252 on the barrel 188 , the end tip 229 of the plunger 190 should be in contact with the holding tire 214 , and the proximal end 231 of the carriage 194 should be in contact with the plug 236 . Thus, as the plunger 190 is then moved distally to retract the carriage 194 , the extension legs 250 a , 250 b are bent outwardly by the shoulder 234 , the holding tire 214 and the plug 236 are moved off of their respective seats, and the spring 196 is released to expand and retract the carriage 194 ( FIG. 15 ) into the interior cavity of the barrel 188 .
FIGS. 16 and 17 show yet another alternative automatic needle retract syringe 254 provided in accordance with aspects of the present invention. The syringe 254 is substantially similar to the syringes 186 , 246 described above with reference to FIGS. 11-15 with the exception of the plunger tip 256 , which is different. In addition, the first tubular section 230 of the plunger 190 has been slightly modified to cooperate with the plunger tip 256 , as further discussed below.
The plunger tip 256 in the present embodiment comprises a distal annular ring 258 and a proximal annular ring 260 , which define a space 262 therein between. The distal and proximal annular rings 258 , 260 form a size-on-size friction fit with the exterior surface of the first tubular section 230 of the plunger. Internally, a projection 264 on the first tubular portion 230 contacts the interior surface of the space 262 of the plunger tip 256 . The contact between the interior surface of the space 262 and the projection 264 provide added resistance against movement of the plunger tip 256 relative to the plunger 190 during proximal movement of the plunger, i.e., during aspiration of a fluid. In addition, the projection 264 establishes a gap between the proximal annular ring 260 and the exterior shoulder 234 formed at the intersection of the first tubular portion 230 and the second tubular portion 232 . Still further, the projection 264 facilitates aspirating fluid into the syringe by securing the plunger tip 256 from falling off of the first tubular portion 230 when the plunger moves proximal. Alternatively, a second projection or flange 172 (as shown in FIGS. 7 and 8 ) can be incorporated just proximal of the plunger tip 256 , just proximal of the annular ring 260 , to further secure the plunger tip 256 on the plunger 190 . If incorporated, the proximal annular ring 260 of the plunger tip 256 would be secured in the gap between both projections 264 and 172 .
When the plunger 190 is in position to retract the carriage 194 ( FIG. 16 ), the plunger tip 256 , plug 236 , and first tubular section 230 of the plunger 190 should occupy substantially all of the head space of the variable volume chamber to minimize fluid waste. In this configuration, the plunger tip 256 should be in contact with the shoulder 252 on the barrel 188 , the end tip 229 of the plunger 190 should be in contact with the holding tire 214 , and the proximal end 231 of the carriage 194 should be in contact with the plug 236 . Thus, as the plunger 190 is then moved distally to retract the carriage 194 , the actuated force F A overcomes the friction between the plunger tip 256 and the first tubular portion 230 and allows the plunger 190 to move relative to the plunger tip 256 . Concurrently therewith, the holding tire 214 and the plug 236 are moved off of their respective seats and the spring 196 is released to expand and retract the carriage 194 ( FIG. 17 ) into the interior cavity of the barrel. In the alternative embodiment (not shown), the most proximal projection 172 (as shown in FIGS. 7 and 8 ) would be forced under the proximal annular ring 260 when an actuated force F A is applied.
Turning now to FIG. 18 , a syringe 266 for use with a needle hub 268 having a spring loaded retractable needle 270 provided in accordance with aspects of the present invention is shown. The barrel 272 in the present embodiment comprises an integrally molded Luer tip 274 and a female lock 276 at the distal end 278 and a grip flange 280 at the proximal end 282 . A plunger 284 is positioned internally of the barrel. The plunger 284 comprises an elongated tube 286 defining a bore 288 , and four rectangular plates or fins 290 attached to the tube 286 with both the fins and tube attached to the push flange 292 , which has an opening 294 for molding the tube 286 and a frangible seal 296 for holding an end cap 297 at the distal end of the tube ( FIGS. 18 and 19 ). Preferably, the bore 288 has a greater inside diameter than the end cap 297 , for reasons explained below. The opening 294 is then sealed with a plug 298 . The plunger 284 also includes a push plate 300 and a distally projecting tip holder 302 , which is located proximal of an extension pin 304 , and which makes up part of the tube 286 . The extension pin 304 is sized to fit within the Luer tip 274 , which is sized to receive the needle hub 268 , as further discussed below. In one exemplary embodiment, the elongated tube 286 is cylindrical in shape. However, other elongated shaped bodies may be incorporated without deviating from the scope of the present invention.
The plunger tip 308 comprises an opening 310 for accommodating the extension pin 304 , a proximal annular ring 312 forming a size-on-size friction fit with the tip holder 302 , and a pair of proximally extending extension legs 314 a , 314 b . In one exemplary embodiment, the extension legs 314 a , 314 b and the annular ring 312 contact both the push plate 300 and the tip holder plate 316 . However, a small gap between the annular ring 312 and the tip holder plate 316 is acceptable.
In one exemplary embodiment, the needle hub 268 useable with the syringe 266 of the present embodiment comprises a housing 318 , which comprises a distal housing structure 320 having a needle 270 protruding therefrom, a proximal housing structure 322 having male threads 320 thereon for threaded engagement with the female lock 276 , a central activation compartment 324 disposed therebetween, and a bore 326 defined therethrough. A generally cylindrical tube 323 with optional support fins 325 are located at the distal end of the needle hub 268 . The bore 326 extends through the cylindrical tube 323 and has a size sufficient to accommodate the needle 270 and a spring 327 , as further discussed below. At the distal end of the cylindrical tube 323 is an annular cap 329 having a close tolerance fit with the outside diameter of the needle 270 . The annular cap 329 provides an anchor and supports one end of the spring 327 , as further discussed below.
Exteriorly, the housing 318 is tapered inwardly in the direction from the proximal housing structure 322 towards the distal housing structure 320 , although a straight cylinder or wall may be acceptable. At the central activation compartment 324 , the housing incorporates two wells 328 a , 328 b ( FIG. 19 ), which form two thin-walled sections 330 with the bore 326 of the hub 268 . The thin-walled sections 330 each include a bulge section 332 that forms a receiving space inside the bore 326 for mating engagement with the needle sleeve 334 , as further discussed below. Referring to FIG. 19 in addition to FIG. 18 , the thin-walled sections 330 of the wells 328 a , 328 b each includes a base section 336 , a transition section 338 , which is tapered or angled from the base section, and a gripping section 340 , where the bulge 332 is located. Alternatively, a single well with a single thin-walled section may be incorporated in the needle hub.
The needle sleeve 334 ( FIG. 19 ) comprises a generally elongated tube that includes a bulge section 342 and a bore. In one exemplary embodiment, the exterior surface 344 of the sleeve 334 comprises an undulating surface for increased gripping engagement with the gripping sections 340 of the wells 328 a , 328 b . To secure the needle 270 to the sleeve 334 , the sleeve bore comprises a glue well 346 for gluing the needle to the sleeve ( FIG. 19 ).
To assemble the needle hub 268 , the spring 327 is first mounted over the combination needle 270 and needle sleeve 334 . The needle 270 and spring 327 are then inserted into the bore 326 of the needle hub 268 from the proximal end opening of the hub. The needle 270 is pushed distally through the bore 326 until the needle sleeve 334 engages the gripping section 340 of the needle hub, at the two wells 328 a , 328 b . In one exemplary embodiment, the engagement is achieved when the bulge 342 on the sleeve 334 fits into the space provided by the bulge 332 of the gripping section 240 .
To retract the needle 270 , the plunger 284 is first moved distally with a distally directed force F D until the distal end surface of the plunger tip 308 contacts the shoulder or end 348 of the barrel 272 . At this point, the extension pin 304 is positioned inside the Luer tip 274 with the end cap 297 on the extension pin 304 slightly spaced apart from the proximal end 350 of the needle 270 ( FIG. 19 ). As an actuated force F A is then applied to the plunger 284 , the push plate 300 moves distally to bend the extension legs 314 a , 314 b inwardly (or outwardly if the extensions legs 314 a , 314 b were positioned closer to the tip holder 302 ). Concurrently therewith, the extension pin 304 moves forward and causes the transition section 338 of the wells 328 a , 328 b to deform outwardly to separate from the bulge 342 on the needle sleeve 334 . The forward motion also pushes the end cap 297 of the extension pin 304 against the proximal end 350 of the needle 270 . Because the needle 270 is anchored by the needle sleeve 334 abutting against the hub 268 , the needle 270 pushes back against the end cap 297 with an equal but opposite force and causes the frangible seal 296 to tear or separate. The proximal end 350 of the needle 270 eventually completely tears the end cap 297 from the extension pin 304 , which then provides a passage for the spring 327 to expand. The expanding spring 327 then pushes the needle sleeve 336 proximally, which is attached to the needle 270 and pushes the needle proximally into the bore 288 located in the plunger 284 to thereby prevent accidental contact with the needle tip. Once the needle is retracted, the syringe may be safely disposed of per normal protocols.
As best shown in FIGS. 18 and 20 , when the actuated force F D is applied to the plunger 284 to retract the needle 270 , the plunger moves distally relative to the plunger tip 308 . As discussed above, this relative movement is provided by a gap between the tip holder plate 316 of the syringe tip holder 302 and the end surface 313 of the plunger tip 308 . Said gap should be of sufficient dimension so as to not delimit the proximal end 350 of the needle 270 from puncturing the frangible seal 296 .
Referring now to FIG. 21 , an alternative syringe 352 for use with a needle hub 268 having a spring loaded retractable needle 270 provided in accordance with aspects of the present invention is shown. The syringe 352 is substantially similar to the syringe 266 described above with reference to FIGS. 18-20 with the exception of the plunger tip 354 , which is different. In addition, the tip holder 356 of the plunger 284 has been slightly modified to cooperate with the plunger tip 354 , as further discussed below.
The plunger tip 354 in the present embodiment comprises an internal bore 358 comprising an internal diameter sized to frictionally engage the exterior surface of the tip holder 356 . As before, a gap for relative movement between the plunger tip 354 and the plunger 284 are provided inside the plunger tip bore, between the distal end of the tip holder 356 and the end surface 360 of the plunger tip 354 . The proximal end of the plunger tip 354 abuts the push plate 300 on the plunger 284 . This contact enables the push plate 300 to move the plunger tip 354 distally when a distally directed force F D is applied, and to compress the plunger tip to retract the needle 270 when an actuated force F A is applied. The mechanism for retracting the needle 270 for the needle hub 268 is the same as that discussed above with reference to the needle hub of FIGS. 18-20 .
Turning now to FIG. 22 , an alternative syringe 362 for use with a needle hub 268 having a spring loaded retractable needle 270 provided in accordance with aspects of the present invention is shown. The syringe 362 is substantially similar to the syringes 266 , 352 described above with reference to FIGS. 18-21 with the exception of the plunger tip 364 , which is different. In addition, the tip holder 366 of the plunger 284 has been slightly modified to cooperate with the plunger tip 364 , as further discussed below.
In the present embodiment, the plunger tip 364 incorporates a groove 368 in the interior bore 358 of the plunger tip. The groove 368 is sized to receive a plunger disc 370 on the plunger 284 and allows it to move distally upon application of an actuated force F A as described below. In one exemplary embodiment, the pusher plate 300 is located apart from the proximal annular ring 372 of the plunger tip 364 when in the ready to use position.
To retract the needle 270 , the plunger is first advanced from a proximal to a distal position shown in FIG. 22 . At this position, the end surface 360 of the plunger tip 364 contacts the end shoulder 348 of the barrel 272 . When an actuated force F A is then applied to the plunger 284 , the plunger disc 370 moves distally within groove 368 of the plunger tip 364 and the plunger 284 moves distally relative to the end surface 360 of the plunger tip. The pusher plate 300 moves to meet the proximal annular ring 372 of the plunger tip 364 . Concurrently therewith, the extension pin 304 contacts the needle 270 to retract the needle as discussed above with reference to FIGS. 18-20 .
Turning now to FIG. 23 , a partial cross-sectional view of an alternative needle hub 374 provided in accordance with aspects of the present invention is shown. The needle hub 374 is substantially similar to the needle hub 268 described above with reference to FIGS. 18-20 with the exception of the way in which the gripping section 340 of the wells 328 a , 328 b of the needle hub grips the needle 376 . The needle hub 374 may be used with any of the syringes 266 , 352 , 362 described above with reference to FIGS. 18 , 21 , and 22 and may be actuated to retract the needle 376 the same way as described with those syringes 266 , 352 , 362 . However, instead of utilizing a needle sleeve 334 ( FIG. 19 ), in the present embodiment, the proximal end of the needle 376 incorporates a crimp or a bulge 378 . The bulge or crimp 378 may be made by pinching the needle to create a crimp or by a controlled compression process to create a bulge.
The needle hub 374 may be assembled by first positioning a spring 327 over the needle 376 , which then rests on an end against the bulge or crimp 378 . The combination needle 376 and spring 327 is then inserted into the bore 326 of the needle hub and pushed distally until the bulge or crimp 378 engages with the space provided by the bulge 332 formed in the thin-walled sections 330 of the wells 328 a , 328 b . Once engaged, the crimp or bulge 378 and the annular ring or cap 329 on the tube section 323 of the needle hub (See, e.g., FIG. 18 ) compresses the spring and loads the needle 376 for retraction.
Although limited embodiments of the syringe assemblies and their components have been specifically described and illustrated herein, many modifications and variations will be apparent to those skilled in the art. Accordingly, it is to be understood that the syringe assemblies and their components constructed according to principles of this invention may be embodied other than as specifically described herein. The invention is defined in the following claims.
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Syringes are disclosed herein incorporating a variety of safety mechanisms for protecting the users from accidental needle stick. In certain embodiments, the syringes incorporate retractable carriages that can be retracted into the syringe barrels by engaging with the plungers. The carriages are configured to receive different needle hubs having any number of needle sizes. In certain other embodiments, the carriages are spring loaded so that as the plungers disengage the carriages from the syringe barrels, the springs automatically retract the needles into the barrels. Still in certain other embodiments, needle hubs with spring loaded needles are used with the syringes. The needles are retracted into the barrels when the plungers activate certain mechanisms incorporated into the hubs to thereby release the needles.
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FIELD OF INVENTION
The present invention relates to a field of microbially produced carotenoid compounds and it relates particularly to the method of extraction of carotenoid compounds such as beta carotene and Lycopene of high purity from fungal biomass and an optimised process of isolating carotenoid compounds of high purity.
BACKGROUND OF THE INVENTION
Carotenoids are the most widespread class of naturally occurring pigments in nature, present without exception in photosynthetic tissue and occurring with no definite pattern in non-photosynthetic tissues such as roots, flower petals, seeds and fruits. They are also found in algae, fungi, yeasts, molds, mushrooms and bacteria. They represent the most extended group of natural pigments that exists in nature. They are used in the industry as food supplements and colorants. They are known for their excellent anti-oxidant properties and as precursors of vitamin A.
Beta-carotene and Lycopene are important carotenoids used widely in Nutraceutical, Pharma, food and animal feed industries as natural antioxidants, functional colour and for food and feed fortification. High purity Carotenoid crystals plays a major role in the various formulations like encapsulation, water soluble powder or emulsion, high concentrate oil dispersion etc.
These high purity carotenoid crystals not only facilitate easier product formulation but also help to deliver high concentrated end products to meet the growing market demands of anti-oxidants and ‘natural, colorants—a number of methods have been proposed and tried—to isolate and purify carotenoids and specifically Beta carotene.
Carotenoids and Beta carotene, in particular can be obtained from natural sources whether vegetal products such as tomato and carrot in which they are very small percentages or starting from cultures of selected algae, fungi etc. in which proportion of these components may increase.
Beta carotene obtained from fermentation broths of certain mucor fungi such as Phycomyces; Blakeslea etc. have certain advantages over the aforementioned natural sources. ie. 1. Elevated concentration of this compound with respect to the quantity of dry biomasses 2. Possible increase in production using ‘enhanced carotenoid producing strains’ obtained by classical mutagenesis/molecular biology techniques; optimisation of fermentation processes, use of “inducers,/‘Inhibitors’.
For example: U.S. Pat. No. 2,959,521 describes enhanced production of beta carotene from fungi Blakeslea trispora in a culture medium containing Lecithin.
U.S. Pat. No. 7,799,540 Describes a process of producing lycopene through the fermentation of selected strains of Blakeslea trispora and extracting lycopene by a process of treating the fermented culture with alcohol and drying the biomass followed by a mechanical milling process to break the cell wall and the disrupted biomass is extracted by an organic solvent and the crystals are recovered by precipitation crystallization by addition of alcohol. The main disadvantage of this process is the mechanical milling method for cell disruption which might cause the loss of Lycopene;
U.S. Pat. No. 7,252,965 Discloses a method of production of Beta-carotene by fermentation of (+) and (−) strains of Blakeslea trispora followed by separation of the wet biomass and treatment with alcohol to dry the biomass for cell rupturing; then the ruptured cell biomass is subjected to solid-liquid extraction with an organic solvent and it is concentrated. Precipitation/crystallization—by adding alcohol thus a pure crystal of purity >95% is obtained. (Similar process is also explained in US application U.S. Pat. Application No. 20040067550) the disadvantage of this process is the mechanical disruption & drying of the biomass which might cause loss of beta-carotene and complexity of using multiple solvents for extraction and precipitation steps.
U.S. Pat. No. 7,015,014 (equivalent to WO 01/55100) teaches a method for the Isolation of Carotenoid crystals by microbial cell disruption to get an oily medium; this oily suspension is treated with water and the PH adjusted by adding alkali and further treated with alcohol or salt to get a filtrate containing beta-carotene crystals. This filtrate is subjected to several washing steps with multiple solvents followed by a separation and dryings step to get purified crystals. This process involves use of larger number of solvents and water media for the purification
International patent application WO 03/038064 A2 describes method of producing lycopene by fermentation of mutated Blakeslea trispora . Lycopene crystals are extracted from the culture broth by means of cell disruption subsequent purification steps using organic solvents such as ethyl acetate, hexane and 1-butanol by adjusting the PH using alkali with optional addition of alcohol or acid to adjust the pH; this is further purified with organic solvent and washed with fresh solvent to give lycopene crystals. This process is highly complex, larger amount of solvents and reagents are used for the purification steps.
U.S. Pat. No. 6,812,001 (equitant to EP 0979302 & WO 01/83437 A1) Describes a method to obtain carotenoid crystals from microbial biomass, the method involves cell wall disruption by homogenization and followed by lipid removal by alcohol treatment. The crystals from the cellular debris is collected by floating in water. According to this method ether salt or oil can be used in the place of water to float crystals, the yield thus obtained is 35% only.
WO 98/50574 Teaches a method of isolating carotenoid crystals from microbial biomass which involves disrupting the microbial cell walls, removing the cellular debris from the resulting carotenoid crystal containing residue. Further solvent added to remove lipid. Then Carotenoids are extracted using ethyl acetate, hexane or oil followed by several purification & washing steps which requires more solvent & water in the process, thus the crystals purity of 93.3% is achieved with an yield of 35% only.
U.S. Pat. No. 5,858,700 Teaches a process for the purification of lycopene crystals by saponifying lycopene containing oleoresin using propylene glycol, alkali and water to recover the crystals
U.S. Pat. No. 5,714,658, Describes a process for the extraction of carotenes from natural sources using a mixture of an acetic acid ester (ethyl acetate or butyl acetate or in combination), and with an edible oil.
U.S. Pat. No. 3,268,606 Describes a process of extracting beta-carotene from fungal biomass by treating the fermented mycelium with alcohol to remove the moisture and extracting the dried mycelium with ethylene chloride or Benzene in several steps to yield a filtrate rich in beta-carotene. This filtrate is further concentrated and subjected to crystallization with acetone and absolute alcohol to recover the high purity beta-carotene crystals. The disadvantage of this process is the complexity in industrial application, usage of toxic solvents like benzene.
U.S. Pat. Application No. 20020025548 (equivalent to WO/1998/003480) discloses a method to extract beta carotene from natural sources by direct extraction with organic solvents, vegetable oils or supercritical fluids, followed by crystallization or precipitation and washing of the crystals with an anti-solvent.
U.S. Pat. Application No. 20060105443 explains a method to isolate lycopene from transformed or naturally derived bacterial cells; the steps in the process comprises: isolating a biomass from a fermented broth; treating the isolated biomass with alcohol; extracting the lycopene from the alcohol treated biomass with methylene chloride; solid mixture is removed and the filtrate is vacuum contracted; the concentrates suspension is washed with acetone to recover lycopene crystals.
U.S. Pat. Application No. 20060234333 (equivalent to WO/2004/063359) discloses a method for producing carotenoids or their precursors using genetically modified organisms of the blakeslea genus. The process involves recovery of biomass from the medium and washing the same with water. Biomass is sterilized and cell disruptions are carried out using steam or microwave radiation followed by extraction using solvents such as dichloromethane or supercritical carbon dioxide or tetrahydrofuran. The filtrate obtained after the extraction is subjected to crystallization step using a carotenoid non soluble solvent.
CN101870668 Discloses a method for preparing beta-carotene from Blakeslea trispora through fermentation & drying the biomass and milling and pulverizing the dry mycelia, followed by solvent extraction using dichloromethane. The major disadvantage of this process is mechanical cell disruption using milling and pulverizing which will lead to loss of beta-carotene.
U.S. Pat. Application No. 20100145116 (equivalent to WO/2008/108674) Describes a process for the production and extraction of Carotenoids without cell disruption by direct solid liquid extraction using a ketone and alcohol (acetone and ethanol or acetone and methanol) followed by a second extraction using a mixture of hydrophobic solvents (hexane and tert-butylmethyl ethe) and finally crystallization. The major disadvantage of the process is using more number of solvents, multiple extraction steps and complicated process.
It is clearly evident that the prior art that the disclosed processes involve: different types & large amount of Organic solvents for the extraction of substantially pure crystals of beta-carotene or lycopene, and the methods are complicated. In most of the cases the purity of the final product is below expectation. The processes for obtaining Beta carotene from fermentation broths described until present generally imply an extraction stage and successive crystallizations and re-crystallizations and even stages of Chromatographic purifications requiring high consumption of solvents. Hence there is a need for a simple, cost effective and industrially viable method for extraction.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the invention is to provide a simple and cost effective method for extracting Carotenoids such a beta-carotene and lycopene from fungal biomass
Another object of the invention is to provide a simple mono-solvent extraction process of recovering substantially pure Carotenoids crystals, where purity is almost 99% without use of further process of purifying with water or adding any other solvents.
Yet another object of this invention is to provide a process with value addition—ie. a process which yields important and commercially useful by-products.
The present invention disclosed a process for production of beta-carotene and lycopene crystals with a purity of minimum 99% from natural sources, especially from fungal biomass produced by the fermentation of Blakeslea trispora to give ready biomass containing carotenoids such as beta-carotene and lycopene. The process comprises of the following steps.
a) Pretreatment of the biomass with acidified alcohol to remove free oils, sugars and other soluble impurities in the biomass and also to increase the cellular porosity for better extraction of carotenoids. b) Two stage extraction of the treated biomass with a mono solvent like ethyl acetate. The initial extraction is with a solvent ratio of 20 times and the second extraction with 10 times ratio of solvent. c) Further concentration of the said extract to 60% of the volume under vacuum condition. d) Crystallization of beta-carotene or lycopene from the said concentrated extract by chilling at low temperature. e) Crystal recovery is done by vacuum filtration. f) Vacuum evaporation of the filtrate from the above step to recover the residue solvent. The concentrations of the mother extract yields a carotenoid rich oleoresin containing Beta-carotene or lycopene respectively. The overall yield of the process is ≧87%. In a preferred embodiment, the method provides beta-carotene or lycopene crystals from a natural source with a purity of ≧99% and byproduct of low purity oleoresin-which is further treated with the spent biomass & the residue of the pretreatment step, to give an animal feed mixture
DETAILED DESCRIPTION OF THE INVENTION
The present invention discloses a process for the production of crystalline Carotenoid with a purity of at least 99%, most preferably 99.9% by a mono-solvent, simple, efficient and highly Cost effective & economically viable industrial extraction process. The extraction efficiency and the purity of the crystals are improved by a pretreatment process acidified ethanol under homogenization at a low temperature.
The acidified ethanol is made out of treating acetic acid or any other acids to the said alcohol at the ratio lower than 4.5% (w/w), preferably lower than 3.5% (w/w), more preferably lower than 2.5% (w/w), most preferably lower than 2.2% (w/w).
The Process of the Invention Comprises the Following Steps:
Carotenoids containing biomass preferably from Fungi Blakeslea trispora is subjected to pretreatment & cellular disruption by mild acidified alcohol treatment, whereas the acid is mild acetic acid and alcohol is ethanol, under homogenization to remove the anti-purity compounds such as free oils, proteins, mineral, carbohydrates, and to increase the cellular porosity to an extend to increasing the efficiency of the extraction process.
Then the pretreated biomass is subjected to mechanical separation to recover the solid biomass for further processing. The filtrate is collected and stored for further processing.
Next step involves a solid liquid extraction using an organic solvent, preferably ethyl acetate at a ratio of 15-40 times, preferably 15-30 times, more preferably 18-25 times, and most preferably 19-22 times. Extraction was carried out at a temperature of about 40° C. to 80° C., more preferably 45° C. to 75° C. and most preferably 48° C. to 60° C.
The extracted mixture is filtered mechanically to separate the mother liquor containing the carotenoid crystals and the spent biomass. The spent biomass is further subjected to a secondary extraction (repeat extraction) with the same organic solvent, ethyl acetate at a ratio of 5-20 times, preferably 7-18 times, more preferably 8-15 times, and most preferably 8.5-12.5 times. Where the extraction was carried out at a temperature of about 40° C. to 80° C., more preferably 45° C. to 75° C. and most preferably 48° C. to 60° C.
The second extracted mixture is filtered mechanically to recover the Mother liquor and the spent biomass, thus the mother liquor collected from the two extraction steps are pooled together to get a homogenous mixture of extracted carotenoids containing suspension.
This is followed by a chilling crystallization method to recover the crystals the chilling temperature is from −5° C. to 10° C., preferably −3° C. to 8° C., more preferably −2.5° C. to 6.5° C., and most preferably −1° C. to 5° C.
The chilled suspension is filtered using high efficient mechanical filter under vacuum to get high purity Beta-carotene or Lycopene crystals.
Finally the recovered crystals are subjected to vacuum drying to remove the remaining solvent traces from the wet crystals, resulting in solvent free high purity Beta-carotene or Lycopene crystals.
The spent mother liquor with traces of carotenoid are concentrated further to produce oleoresin with 1-5% Beta-carotene or Lycopene, preferably 1.5-4.5%, more preferable 1.6 to 4.0% and most preferably 1.7 to 3.9%,
The oleoresin, spent biomass and residue from the first step pretreatment are blended along with ingredients like filler, binders and further extruded to produce value added pellets for animal feed application and other application. The fillers like cellulose, dextrin, gums etc are used and the binder such as cellulose based, starch based, etc are used.
EXAMPLES 1
50 gms of Blakeslea trispora biomass containing 62.20 gms/kg of beta-carotene is loaded into 0.5 liter capacity round bottomed flask with an agitator, To this 150 ml of acidified ethanol with 2% acetic acid in ethanol is added at room temperature of 35 deg C., then this mixture is stirred for 30 min. Once the treatment is completed, the treated mixture is vacuum filtered to yield 53.4 Gms of biomass. Then the treated biomass is transferred into 5 liter capacity round bottomed flask, to which 1000 ml of ethyl acetate is added. This mixture is homogenized for an hour under stirring at a temperature of about 50 deg C. in hot water bath system. After one hour, the mixture is vacuum filtered to give 47.3 gms of extracted biomass and 980 ml of Mother liquor. The Mother liquor is kept stored for further beta-carotene recovery. Then the extracted biomass is taken for second extraction with 500 ml of ethyl acetate at the same conditions like the first extraction. After second extraction, 426 ml of Mother liquor and 47.2 gms of spent biomass were recovered. The spent biomass is further treated and used for feed application. The Mother liquor from both the first and second extraction were pooled in 2000 ml round bottomed flask and concentrated till 60% of the volume and then chilled at 5 deg C. in cold water bath for an hour's time for the crystallization of betacarotene. After chilling, the mother liquor is vacuum filtration to recover crystals and then dried under vacuum, obtaining 2.16 gms of betacarotene crystals with a spectrophotometric purity of 99.30%. The filtered mother liquor is completely distilled under vacuum to recover 15.23 gms of betacarotene oleoresin with a spectrophotometric purity of 1.16%. In this process the total yield is about 89.96%.
EXAMPLES 2
50 gms of Blakeslea trispora biomass containing 62.20 gms/kg of beta-carotene is loaded into 0.5 liter capacity round bottomed flask with an agitator, To this 150 ml of acidified ethanol with 2% acetic acid in ethanol is added at room temperature of 35 deg C., then this mixture is stirred for 30 min. Once the reaction is completed, the reaction mixture is vacuum filtered to yield 51.2 Gms of treated biomass. Then the treated biomass is then transferred into 5 liter capacity round bottomed flask, to which 1000 ml of ethyl acetate is added. This mixture is homogenized for an hour under stirring at a temperature of about 50 deg C. in hot water bath system. After one hour, the mixture is vacuum filtered to give 49.1 gms of extracted biomass and 988 ml of Mother liquor. The Mother liquor is stored for further beta-carotene recovery. Then the extracted biomass is taken for second extraction with 500 ml of ethyl acetate at the same conditions like the first extraction. After second extraction, 442 ml of Mother Liquor and 49.1 gms of spent biomass were recovered. The spent biomass is further treated and used for feed application. The Mother liquor from both the first and second extraction were pooled in 2000 ml round bottomed flask, without concentration the mixture is chilled at 5 deg C. in cold water bath for an hour's time for the crystallization of beta-carotene. After chilling, the mother liquor is vacuum filtration to recover crystals and then dried under vacuum, obtaining 2.53 gms of beta-carotene crystals with a spectrophotometric purity of 99.01%. The filtered mother liquor is completely distilled under vacuum to recover 10.23 gms of beta-carotene oleoresin with a spectrophotometric purity of 2.16%. In this process the total yield is about 79.68%.
EXAMPLES 3
500 gms of Blakeslea trispora biomass containing 62.20 gms/kg of beta-carotene is loaded into 5.0 liter capacity round bottomed flask with an agitator, To this 1500 ml of acidified ethanol with 2% acetic acid in ethanol is added at room temperature of 35 deg C., then this mixture is stirred for 30 min. Once the reaction is completed, the reaction mixture is vacuum filtered to yield 518.0 Gms of treated biomass. Then the treated biomass is then loaded into 15 liter capacity round bottomed flask, to which 10000 ml of ethyl acetate is added. This mixture is homogenized for an hour under stirring at a temperature of about 50 deg C. in hot water bath system. After one hour, the mixture is vacuum filtered to give 494.0 gms of extracted biomass and 9100 ml of Mother liquor. The Mother liquor is stored for further beta-carotene recovery. Then the extracted biomass is taken for second extraction with 5000 ml of ethyl acetate at the same conditions like the first extraction. After second extraction, 4400 ml of Mother Liquor and 494 gms of spent biomass were recovered. The spent biomass is further treated and used for feed application. The Mother liquor from both the first and second extraction were pooled in 20 liter round bottomed flask and concentrated till 60% of the volume and then chilled at 5 deg C. in cold water bath for an hour's time for the crystallization of beta-carotene. After chilling, the mother liquor is vacuum filtration to recover crystals and then dried under vacuum, obtaining 25.731 gms of beta-carotene crystals with a spectrophotometric purity of 99.07%. The filtered mother liquor is completely distilled under vacuum to recover 173.24 gms of beta-carotene oleoresin with a spectrophotometric purity of 1.46%. In this process the total yield is about 90.10%.
EXAMPLES 4
5.0 kg of Blakeslea trispora biomass containing 62.20 gms/kg of beta-carotene is loaded into 150 liter capacity pilot plant with an agitator, To this 15 liter of acidified ethanol with 2% acetic acid in ethanol is added at room temperature of 35 deg C., then this mixture is stirred for 30 min. Once the reaction is completed, the reaction mixture is centrifuged to yield 5.24 kg of treated biomass. Then the treated biomass is then loaded into 150 liter capacity pilot plant, to which 100 liter of ethyl acetate is added. This mixture is homogenized for an hour under stirring at a temperature of about 50 deg C. in hot water bath system. After one hour, the mixture is vacuum filtered to give 4.84 kg of extracted biomass and 91 liter of Mother Liquor. The Mother liquor is stored for further beta-carotene recovery. Then the extracted biomass is taken for second extraction with 50 liter of ethyl acetate at the same conditions like the first extraction. After second extraction, 42 liter of Mother liquor and 5.12 kg of spent biomass were recovered. The spent biomass is further treated and used for feed application. The Mother liquor from both the first and second extraction were pooled in 200 liter round bottomed flask and concentrated till 60% of the volume and then chilled at 5 deg C. in cold water bath for an hour's time for the crystallization of beta-carotene. After chilling, the mother liquor is vacuum filtration to recover crystals and then dried under vacuum, obtaining 245.8 gms of beta-carotene crystals with a spectrophotometric purity of 99.34%. The filtered mother liquor is completely distilled under vacuum to recover 1473.32 gms of beta-carotene oleoresin with a spectrophotometric purity of 2.09%. In this process the total yield is about 88.41%.
EXAMPLE 5
500 gms of Blakeslea trispora biomass containing 37.20 gms/kg of Lycopene is loaded into 5.0 liter capacity round bottomed flask with an agitator, To this 1500 ml of acidified ethanol with 2% acetic acid in ethanol is added at room temperature of 35 deg C., then this mixture is stirred for 30 min. Once the reaction is completed, the reaction mixture is vacuum filtered to yield 481.0 Gms of treated biomass. Then the treated biomass is then loaded into 15 liter capacity round bottomed flask, to which 10000 ml of ethyl acetate is added. This mixture is homogenized for an hour under stirring at a temperature of about 50 deg C. in hot water bath system. After one hour, the mixture is vacuum filtered to give 442.0 gms of extracted biomass and 9100 ml of Mother liquor. The Mother liquor is stored for further beta-carotene recovery. Then the extracted biomass is taken for second extraction with 5000 ml of ethyl acetate at the same conditions like the first extraction. After second extraction, 4600 ml of Mother Liquor and 464 gms of spent biomass were recovered. The spent biomass is further treated and used for feed application. The Mother liquor from both the first and second extraction were pooled in 20 liter round bottomed flask and concentrated till 60% of the volume and then chilled at 5 deg C. in cold water bath for an hour's time for the crystallization of Lycopene. After chilling, the mother liquor is vacuum filtration to recover crystals and then dried under vacuum, obtaining 15.55 gms of lycopene crystals with a spectrophotometric purity of 99.85%. The filtered mother liquor is completely distilled under vacuum to recover 30.5 gms of beta-carotene oleoresin with a spectrophotometric purity of 2.90%. In this process the total yield is about 88.23%.
The present invention discloses a production of crystalline Carotenoid with very high purity; purity of almost 99% or more, most preferably 99.9% by a mono-solvent simple, efficient and economical extraction process. The extraction efficiency and the purity of the crystals are improved by a pretreatment process of acetic acid acidified ethanol under homogenization at a low temperature.
The acidified ethanol, is meant an amount of acetic acid or other acids in the solvent of lower than 4.5% (w/w), preferably lower than 3.5% (w/w), more preferably lower than 2.5% (w/w), most preferably lower than 2.2% (w/w).
The process of the invention: Example: (a) Disintegration of carotenoid-containing biomass, preferably from Fungi spp. Including Blakeslea by mild acidified alcohol treatment, whereas the acid is mild acetic acid and alcohol is ethanol, under homogenization to remove the anti-purity compounds such as free oils, proteins, mineral, carbohydrates, etc., to an extend to increasing the efficiency of the process.
(b) Mechanical separation of the treated biomass to recover the solid biomass for further processing.
(c) The treated biomass is then extraction with an organic solvent, preferably ethyl acetate at a ratio of 15-40 times, preferably 15-30 times, more preferably 18-25 times, and most preferably 19-22 times.
(d) The extracted mixture is filtered mechanically to recover the Mother liquor and the spent biomass.
(e) The spent biomass is extracted for the second time with the same organic solvent, ethyl acetate at a ratio of 5-20 times, preferably 7-18 times, more preferably 8-15 times, and most preferably 8.5-12.5 times.
(f) The second extracted mixture is filtered mechanically to recover the Mother liquor and the spent biomass
(g) The high pure crystals are recovered from the pooled mother liquor of both the extraction under chilling condition, the chilling temperature is from −5° C. to 10° C., preferably −3° C. to 8° C., more preferably −2.5° C. to 6.5° C., and most preferably −1° C. to 5° C.
(h) The high pure crystals of carotenoid are recovered by the mechanical separator.
(i) The solvent traces are removed from the isolated crystal by vacuum drying to give solvent free high purity crystals.
(j) The spent mother liquor with traces of carotenoid are concentrated further to produce oleoresin with 1-5% Carotenoid, preferably 1.5-4.5%, more preferable 1.6 to 4.0% and most preferably 1.7 to 3.9%,
(k) The oleoresin, spent biomass and residue from the pretreatment are blended along with ingredients like filler, binders and further extruded to produce value added pellets for animal feed application and other application. The fillers like cellulose, dextrin, gums etc are used and the binder such as cellulose based, starch based, etc are used. The foregoing description is to be considered as illustrative only and not meant to limit the scope of the invention.
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The present invention relates to a simple and economic method of extracting a crystalline Carotenoid compound, such as Beta-carotene, Lycopene, with a purity of at least 99%. The present invention further describes a process to prepare such a highly pure crystalline Carotenoid compound from microbial biomass, using an Anti-purity compound removal process followed by a mono-solvent extraction method. Further the process describes value addition of the co-products recovered during the extraction process thus resulting in a highly economical industrial method for the production of such high purity crystalline Carotenoids compound.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of the earlier filing date of U.S. Provisional Application No. 60/913,486, filed Apr. 23, 2007.
The present application is related to U.S. patent application Ser. No. 11/729,662, entitled “System for Capturing and Presenting Text Using Video Image Capture for Optical Character Recognition,” filed Mar. 28, 2007, now pending, U.S. patent application Ser. No. 11/729,664, entitled “Method for Capturing and Presenting Text Using Video Image Capture for Optical Character Recognition,” filed Mar. 28, 2007, now pending, U.S. patent application Ser. No. 11/729,665, entitled “Method for Capturing and Presenting Text While Maintaining Material Context During Optical Character Recognition,” filed Mar. 28, 2007, now pending, an application (Application No. unknown) entitled “System for Capturing and Presenting Text While Maintaining Material Context During Optical Character Recognition,” filed Mar. 28, 2007, now pending, and PCT application No. PCT/US07/65528, entitled “Capturing and Presenting Text Using Auditory Signals,” filed Mar. 28, 2007, which claim the benefit of provisional application Nos. 60/811,316, filed Jun. 5, 2006 and 60/788,365, Filed Mar. 30, 2006, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The embodiments of the present invention relate generally to the area of adaptive devices designed to aid individuals having one or more impairments, such as, for example dyslexia or low vision. More specifically, embodiments of the invention relate to systems and devices that are capable of transforming printed text obtained from a variety of sources or media formats into more user-accessible forms.
2. Background Information
The conveyance of information through text-based media is a ubiquitous phenomena in society. For some, however, the ability to acquire information contained in text-based media can be a daunting if not impossible task. Such individuals include, for example, those having learning difficulties, blindness, and visual impairments such as those arising from diabetic retinopathy, cataracts, age-related macular degeneration (AMD), and glaucoma.
Recent studies indicate that at least one in twenty individuals has dyslexia, a reading disability and the most common type of recognized learning disability (LD), and at least one in ten is affected with other forms of LD that limit the ability to read or write symbols. Reading-related LDs are genetic neurophysiological differences that affect a person's ability to perform linguistic tasks such as reading and spelling. A disability can vary across a population, exhibiting varying degrees of severity and amenability to remediation. The precise cause or pathophysiology of LDs such as dyslexia remains a matter of contention. Current efforts to remediate reading difficulties, such as dyslexia, fall short of remedying the difficulty in a large proportion of affected individuals. Further, the lack of systematic testing for the disability leaves the condition undetected in many adults and children.
In addition to the LD population, there is a large and growing population of people with poor or no vision. As the populations in many countries age, the low/no vision population is increasing. Difficulties in reading can interfere with performance of simple tasks and activities, and deprive affected individuals of access to important text-based information. Thus a need exists to provide individuals who are unable to read well or at all with the ability to garner information from text-based sources.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 provides a basic drawing of a device capable of capturing and transforming text images according to embodiments of the invention.
FIG. 2 provides an example of a user employing a device to capture and transform text from a printed medium, such as a magazine or a book.
FIG. 3 provides a basic drawing of a second device capable of capturing and transforming text images.
FIGS. 4A and 4B provide a picture of an additional exemplary device capable of capturing and transforming text images.
FIG. 5 diagrams optional exemplary functionality that can be provided with a text capture and transformation device.
FIG. 6 provides a diagram showing several exemplary peripheral devices that may optionally be used in conjunction with a text capture and transformation device.
FIG. 7 provides a drawing of an exemplary stand and holder apparatus adapted to hold and position the text capture and transformation device above a text source that may optionally be used in conjunction with a text capture and transformation device.
FIGS. 8A and 8B show an exemplary text capture and transformation device having two lenses through which a camera internal to the device can capture images.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention provide methods, systems, and apparatuses, including graphical user interfaces and output capabilities, for capturing and presenting text to a user. Embodiments of the invention facilitate the capture of text from a source, such as for example, a magazine, a book, a restaurant menu, a train schedule, a posted sign or advertisement, an invoice or bill, a package of food or clothing, or a textbook and the presentation of the textual content in a user-accessible format, such as for example, an auditory format, a Braille format, or a magnified textual format, in the original language or a different language. As described more fully herein, embodiments of the invention may also optionally provide additional features, such as for example, those found in a personal assistant, such as calendaring, email, and note recording functionalities, connectivity to the internet or a cellular network, library and archiving functionalities, direct connectivity with a computer, speaker system, Braille output or input system, or external camera.
FIG. 1 provides a drawing of a device according to embodiments of the invention that is capable of capturing an image and providing an output related to the captured image to a user, such as, for example, deciphering the text contained in the image and reading the text aloud to a user. The device of FIG. 1 is a mobile computing device. The device of FIG. 1 has a body 10 , user interface or display screen 20 , a camera 30 , input devices 40 , and output devices and or input/output ports 50 . Optionally, the user interface screen may be located in a different position and/or be a different relative size to the size of the device. Similarly, the configuration, location, and or number of input devices 40 and output devices or input/output ports 50 located in the body of the device is not fixed at the exemplary arrangement shown and may be varied depending on the use(s) to which the device may be put. An important aspect of this exemplary design, however, is the location of the camera 30 relative to the user interface screen 20 . As can be seen from FIG. 1 , the camera, and more specifically the camera lens is located in a face that is adjacent to the face of the body in which the interface screen. In the pictured embodiment, the line of sight of the camera lens combination is 90 degrees from the line of sight of the user interface, allowing a user to look at the device screen and image material on a surface below the device simultaneously. In alternate embodiments, the angle formed by the line of site for the camera and the line of site for the user interface screen may be an angle that is less than 170 degrees. The formation of an angle between the lines of site for the user interface screen and the camera that is less than 170 degrees may be accomplished by having a user interface screen that is capable of popping out or being pushed inward from the face of the device in which it is housed to create a comfortable viewing angle. This adjacent-face location enables a user to comfortably and accurately operate the device in a manner, for example, as shown in FIG. 2 . In general, the user interface screen or display allows a user to interact with the device. It can be a touch screen, in which the user is able to input information and or a screen that provides information to the user about the device, such as, for example, the operations that the device is currently and or is capable of performing, the information that is stored on the device, and or information that can be obtained from other sources, such as the internet or an external library.
In FIG. 2 , a user of a text capture and transformation device 100 having a camera lens 110 (not shown) located in a face adjacent to the face of the device having a user interface screen 120 is capturing text from a book or magazine 130 that has been placed on a table top. As further shown in FIG. 2 , a text transformation device 100 may optionally be equipped with a light source (not shown) that is capable of illuminating an area 140 (shown as a dotted line in FIG. 2 ) from which the camera (not shown) captures an image of an object 130 , such as the pages of a book or a magazine. The text transformation device 100 may further optionally contain a mechanism for indicating to a user the metes and bounds of the area from which the device's camera is able to capture an image to aid the user in aligning the device relative to text to be captured. For example, the mechanism may be a light that highlights using continuous or blinking light some or all of the outline of the image capture area.
FIG. 3 provides a drawing of a further device according to embodiments of the invention that is capable of capturing an image and providing an output related to the captured image to a user. The device of FIG. 3 has a body 100 , user interface screen 120 , a camera (not shown), input devices 140 , and output devices and or input/output ports 150 . Optionally, the user interface screen may be located in a different position and/or be a different relative size to the size of the device. Similarly, the configuration, location, and or number of input 40 and output devices or input/output ports 50 located in the body of the device is not fixed at the exemplary number shown and may be varied depending on the use(s) to which the device may be put. The device shown in FIG. 3 additionally comprises a missing corner, or a cut-out corner, so that the resulting body has seven rather than six sides. To describe the cut-out corner feature further, the body of the text transformation device comprises two parallel faces that are five-sided, and four faces that are four-sided. Importantly, the corner cut-out feature allows a user to quickly orient the text transformation device using the sense of touch and also optionally provides a comfortable location for a manual input device, such as, for example a button that instructs the camera to capture an image when the button is depressed by a user.
FIGS. 4A and 4B provide pictures of an exemplary device. FIG. 4A provides a view facing the device's user interface screen. In this example, the face of the device containing a user interface screen additionally has input buttons, including navigation buttons that allow a user to navigate through, for example, an operating or a file system or a text that has been captured. FIG. 4B provides a side view of the same exemplary device in which a camera lens is visible. In the device of FIGS. 4A and 4B the line of site for the user interface screen is 90 degrees from the line of site for the camera. Additionally, the device of FIGS. 4A and 4B contains a cut-out corner having a button that operates the device's camera for image capture, as described above in conjunction with FIG. 3 . The cut-out corner allows a user, among other things, to quickly orient the device using a sense of touch and capture an image of an object.
FIG. 5 diagrams an optional configuration and diagram of capabilities for an exemplary text capture device according to the present invention. For example, a user interface screen may display a home screen from which a library function housing lists that allow dynamic, custom access to files and file management and bookmarks, a notes function that allows access to and management of notes, such as audio notes, a status function that provides information about memory and battery status and performs basic diagnostics, a settings function, and applications folder that provide functions such as GPS, calendaring, and email, can be navigated to. Additionally, from a home screen, functions for allowing text capture (camera aiming and object framing) can be navigated to, allowing a user quick access to text content. Functions may be controlled by input devices, such as navigation buttons, and play and volume buttons. Additional input buttons or devices may be provided that allow a user to access help functions, navigate and skim text, change volume associated with output, such as through headphones or speakers, or increase the size of text displayed.
A display or a user interface screen may comprise any suitable display unit for displaying information appropriate for a mobile computing device. A display may be used by the invention to display, for example, file trees and text, and to assist with input into the text capture device. Input devices include, for example, typical device controls, such as volume controls, recording and playback controls, and navigation buttons. Examples for input/output (I/O) device(s) include an alphanumeric keyboard, a numeric keypad, a touch pad, input keys, buttons, switches, rocker switches, microphones, a speaker, Braille input pads or boards, cameras, and voice recognition device and software. Information entered by way of a microphone may be digitized by a voice recognition device. Navigation buttons can comprise an upward navigation button, a downward navigation button, a leftward navigation button, and a rightward navigation button. Navigation buttons also may comprise a select button to execute a particular function.
Embodiments of the invention provide mobile or portable computing devices. A mobile computing device may refer to any device having a processing system, a memory, and a mobile power source or supply, such as one or more batteries or solar cells, for example. Although a number of functionalities are discussed herein, embodiments of the present invention are not so limited and additional functionalities are possible, such as those commonly available with a laptop computer, ultra-laptop computer, portable computer, handheld computer, palmtop computer, personal digital assistant (PDA), cellular telephone, combination cellular telephone/PDA, smart phone, pager, one-way pager, two-way pager, messaging device, data communication device, and or a music player (such as a mp3 player). Such functionalities include, for example, an ability to store, catalogue, and play music, to send and or receive text messages, to send and receive email, to store and access lists of contacts and important personal information, and an ability to calendar important dates and appointments. Additional functionalities include, the ability to connect to the internet with either a hard connection or a wireless connection. Access to the internet allows the device, for example, to search the internet to determine if the text being translated has already been decoded into an audio format.
In general, transformation, deciphering, and decoding mean capturing text, language, and or forms of communication in one format or medium and storing or outputting it in a different medium or format. For example, a device according to the present invention may capture text from a printed source, such as for example, a book, a magazine, a food package, a letter, a bill, a form of monetary currency, a class syllabus, a sign, a notice, a durable good package, an instruction sheet or pamphlet, and translate it into digital a file stored in memory, an auditory signal such as, a voice that reads the text contained in the printed source to a user, an output on a computer screen, or a Braille output device. Additional output devices include for example, an internal speaker, an amplifier, jack, or connection for headphones or for external speakers. Optionally, the decoding and transformation function may be further augmented by software that, for example, is capable of recognizing a particular type of document that is frequently referred to, such as for example, a bus schedule, a restaurant menu, a check or bank draft, or monetary forms (currency). In the case of currency, the ability to recognize the object as currency enables the device to quickly inform the user about the most relevant information, the currency's denomination (e.g., a one dollar bill or a twenty dollar bill) or the value on a bank draft. The object recognition may occur as a result of a user input or as a result of a software-driven object recognition process. In general, the ability to recognize an object allows the text transformation device to tailor its output to immediately include the information that is most relevant to the user. For example, in the case of currency, the user may desire to know quickly know the denomination rather than waiting for the device to capture all the text and output the text found on the currency (object) in a linear fashion. Image recognition capabilities are available through commercial software solutions, for example. Further, the device may be equipped with capabilities that allow the user to scan larger print or bold type in a text to search for articles or information that they are interested in, or that allows a user to quickly scan a label to look for certain nutritional information. For example, scanning for larger, differentially colored, italicized, or bold-faced type allows the user to quickly jump to sections of a menu, newspaper, or magazine that the user might be interested in, rather than having the device output text content in a linear fashion.
Embodiments of the invention comprise an imaging system that is configured to capture an image digitally for subsequent OCR processing of text contained within the image. As used herein, the term capture or capturing refers to capturing a video stream or photographing an image and is to be distinguished from scanning across the surface of an object to capture an image of the object. For example, scanning can involve placing the printed material to be recorded flat against a glass surface an having a scanner behind the glass scan the object or drawing a scanning device across the surface of a page. Advantages associated with capturing a text-based image via digital photography, as opposed to scanning, include greater ease of use and adaptability. Unlike with a scanner, the imaging device need not be placed flush against the surface to be imaged, thereby allowing the user the freedom and mobility to hold the imaging device at a distance from the surface, e.g., at a distance that is greater than a foot from the page of a book. Thus, such an imaging device is adaptable enough for imaging uneven surfaces such as a pill bottle or an unfolded restaurant menu, as well as substantially planar surfaces such as a street sign. Accordingly, some embodiments of the invention can capture images from both planar and non-planar objects. Capturing the image in such a manner allows for rapid acquisition of the digital images and allows for automated or semi-automated page turning.
Optionally, the imaging system includes a power source (such as, for example, one or more batteries, alternating or direct current acceptance capability, and solar cells), a plurality of lenses, a level detection mechanism, a zoom mechanism, a mechanism for varying focal length, an auto focus mechanism, a mechanism for varying aperture, a video capture unit, such as those employed in closed-circuit television cameras, and a shutter. An optional color sensor within the text capture device allows for the sensing of color present in an image that is captured. The sensing of color allows additional information to be obtained, such as for example, if the title and headings or certain features of a textual display are present in different colors, the text can be more rapidly sorted and desired information presented to the user. Further possible components include for example, a LED strobe, to facilitate image capture at distances less than 12 inches from the device, a xenon lamp, to facilitate image capture at distances greater than 12 inches from the device, headphone jacks and headphones, stereo speakers, connectivity options, such as USB OTG (universal serial bus on the go), and docking, remote control connections, targeting and aiming lights (that, for example, indicate with light the image capture area so that the user can align the device to capture the desired text), microphones, and power cables.
To optimize the quality of the captured image, embodiments optionally include a level detection mechanism that determines whether the imaging device is level to the surface being imaged. Any level detection mechanisms known in the art may be used for this purpose. The level detection mechanism communicates with an indicator that signals to the user when the device is placed at the appropriate angle (or conversely, at an inappropriate angle) relative to the surface being imaged. The signals employed by the indicator may be visual, audio, or tactile. Some embodiments include at least one automatically adjustable lens and or mirror that can tilt at different angles within the device so as to be level with the surface being imaged and compensate for user error.
To avoid image distortion at close range, embodiments may optionally include a plurality of lenses, one of which is a MACRO lens, as well as a zoom mechanism, such as digital and/or optical zoom. In certain embodiments, the device includes a lens operating in Bragg geometry, such as a Bragg lens. Embodiments can include a mechanism for varying the focal length and a mechanism for varying the aperture within predetermined ranges to create various depths of field. The image system is designed to achieve broad focal depth for capturing text-based images at varying distances from the imaging device. Thus, the device is adaptable for capturing objects ranging from a street sign to a page in a book. The minimum focal depth of the imaging device corresponds to an f-stop 5.6, according to certain embodiments. In some embodiments, the imaging device has a focal depth of f-stop 10 or greater.
In certain embodiments, the imaging device provides a shutter that is either electrical or mechanical, and further provides a mechanism for adjusting the shutter speed within a predetermined range. In some embodiments, the imaging device has a minimum shutter speed of 1/60ths. In other embodiments, the imaging device has a minimum shutter speed of 1/125ths. Certain embodiments include a mechanism for varying the ISO speed of the imaging device for capturing text-based images under various lighting conditions. In some embodiments, the imaging device includes an image stabilization mechanism to compensate for a user's unsteady positioning of the imaging device.
In addition to the one-time photographic capture model, some embodiments further include a video unit for continuous video capture. For example, a short clip of the image can be recorded using the video capture unit and processed to generate one master image from the composite of the video stream. Thus, an uneven surface, e.g., an unfolded newspaper which is not lying flat, can be recorded in multiple digital video images and accurately captured by slowly moving the device over the surface to be imaged. A software component of the imaging system can then build a final integrated composite image from the video stream for subsequent OCR processing to achieve enhanced accuracy. Similarly, a streaming video input to the imaging system can be processed for subsequent OCR processing. Software that performs the above described function is known in the art. Accordingly, both planar and non-planar objects can be imaged with a video unit employing continuous video capture.
Additionally, some embodiments include one or more light sources for enhancing the quality of the image captured by the device. Light sources known in the art can be employed for such a purpose. For example, the light source may be a FLASH unit, an incandescent light, or an LED light. In some embodiments, the light source employed optimizes contrast and reduces the level of glare. In one embodiment, the light source is specially designed to direct light at an angle that is not perpendicular to the surface being imaged for reducing glare.
In some embodiments, the image capturing system further includes a processor and software-implemented image detectors and filters that function to optimize certain visual parameters of the image for subsequent OCR processing. To optimize the image, especially images that include colored text, for subsequent OCR processing, some embodiments further include a color differential detection mechanism as well as a mechanism for adjusting the color differential of the captured image.
In some embodiments, the imaging system further includes CMOS image sensor cells. To facilitate users with unsteady hands and avoid image distortion, handheld embodiments further include an image stabilization mechanism, known by those of ordinary skill in the art.
The system can include a user interface comprising a number of components such as volume control, speakers, headphone/headset jack, microphone, and display. The display may be a monochromatic or color display. In some embodiments, an LCD display having a minimum of 640×480 resolution is employed. The LCD display may also be a touch screen display. According to certain embodiments, the user interface includes a voice command interface by which the user can input simple system commands to the system. In alternative embodiments, the system includes a Braille display to accommodate visually impaired users. In still other embodiments, the Braille display is a peripheral device in the system.
OCR systems and text reader systems are well-known and available in the art. Examples of OCR systems include, without limitation, FineReader (ABBYY), OmniPage (Scansoft), Envision (Adlibsoftware), Cuneiform, PageGenie, Recognita, Presto, TextBridge, amongst many others. Examples of text reader systems include, without limitation, Kurzwell 1000 and 3000, Microsoft Word, JAWS, eReader, WriteOutloud, ZoomText, Proloquo, WYNN, Window-Eyes, and Hal. In some embodiments, the text reader system employed conforms with the DAISY (Digital Accessible Information System) standard.
In some embodiments, the handheld device includes at least one gigabyte of FLASH memory storage and an embedded computing power of 650 mega Hertz or more to accommodate storage of various software components described herein, e.g., plane detection mechanism, image conditioners or filters to improve image quality, contrast, and color, etc. The device may further include in its memory a dictionary of words, one or more translation programs and their associated databases of words and commands, a spellchecker, and thesaurus. Similarly, the handheld device may employ expanded vocabulary lists to increase the accuracy of OCR with technical language from a specific field, e.g., Latin phrases for the practice of law or medicine or technical vocabularies for engineering or scientific work. The augmentation of the OCR function in such a manner to recognize esoteric or industry-specific words and phases and to account for the context of specialized documents increases the accuracy of the OCR operation.
In still other embodiments, the handheld device includes a software component that displays the digital text on an LCD display and highlights the words in the text as they are read aloud. For example, U.S. Pat. No. 6,324,511, the disclosure of which is incorporated by reference herein, describes the rendering of synthesized speech signals audible with the synchronous display of the highlighted text.
The handheld device may further comprise a software component that signals to the user when the end of a page is near or signals the approximate location on the page as the text is being read. Such signals may be visual, audio, or tactile. For example, audio cues can be provided to the user in the form of a series of beeps or the sounding of different notes on a scale. Signaling to the user that the end of the page provides a prompt for the user to turn the page, if manual page-turning is employed.
The handheld device may further include a digital/video magnifier. Examples of digital magnifiers available in the art include Opal, Adobe, Quicklook, and Amigo. In certain embodiments, the digital/video magnifier transfers the enlarged image of the text as supplementary inputs to the OCR system along with the image(s) obtained from the image capturing system. In other embodiments, the magnifier functions as a separate unit from the rest of the device and serves only to display the enlarged text to the user.
In various embodiments, the devices of the present invention may be implemented as wireless systems, wired systems, or a combination of both. When implemented as a wireless system, transformation devices may include components and interfaces suitable for communicating over a wireless shared media, such as one or more antennas, transmitters, receivers, transceivers, amplifiers, filters, control logic, and so forth. An example of wireless shared data may include portions of a wireless spectrum, such as the RF spectrum and so forth. Examples of wireless communication methods include, Bluetooth, ZigBee, wireless local area networks (WLAN), Wi-Fi (WLAN based on IEEE 802.11 specifications), Wi-Pro, WiMax, and GPS (global positioning systems). When implemented as a wired system, a transformation device may include components and interfaces suitable for communicating over wired communications media, such as input/output (I/O) adapters, physical connectors to connect the I/O adapter with a corresponding wired communications medium, a network interface card (NIC), disc controller, video controller, audio controller, and so forth. Examples of wired communications media may include a wire, cable, metal leads, printed circuit board (PCB), backplane, switch fabric, semiconductor material, twisted-pair wire, co-axial cable, fiber optics, and so forth.
Certain embodiments further include a data port for data transfer, such as transfer of images, from the system to a computing station. For example, the data port can be a USB 2.0 slot for wired communication with devices, and or communication may be wirelessly-enabled with 802.11a/b/g/n (Wi-Fi) standards, and or using a infrared (IR) port for transferring image data to a computing station. Still another embodiment includes a separate USB cradle that functions as a battery charging mechanism and/or a data transfer mechanism. Still other embodiments employ Bluetooth radio frequency or a derivative of Ultra Wide Band for data transfer.
FIG. 6 provides some exemplary peripherals and modes of operation that are useful with devices of the present invention. For example, the present invention may be connected to a personal computer (a PC) to allow software updates, new software to be added, and or data and files to be stored on or transferred to the computer. The device may also be connected to external devices having memory capability in order to store and or archive the contents of the text transformation device. The text transformation device might be connected to head phones, speakers, or other types of sound-output devices that allow text to be read to the user or auditory prompts to be amplified or heard privately. A remote may also be used to control the functionality of the device. A stand may be used to position the device above a text to be captured. An exemplary stand is shown in FIG. 7 . A stand is useful, for example, for capturing multiple pages of a book in succession.
FIG. 7 provides an exemplary apparatus for holding and or positioning text capture device 100 . The stand of FIG. 7 has collapsible arm 200 , a mechanism for holding the text capture device 100 , and is attached to a foldable book plate 220 . A portable imaging device 100 can be docked using docking mechanism of the holding device 210 . The collapsible arm 200 and book frame 220 allows for the imaging device to be placed at an optimal distance from a book or other object for image capture by the device. The stand may also include a holding strip 230 for holding down the pages of a book or magazine. The system includes modules for OCR processing and for converting the digital text to speech. In certain embodiments, the system includes a mechanism for determining whether a page has been turned by comparing the text from the two pages or by responding to a manual input from the user engaging the digital shutter. Some embodiments include a display screen for displaying the digital text. In yet other embodiments, a Braille machine is included for outputting the digital text. The text capture device may also include an output to alert the user that the image capture is complete for the object and the page should be turned.
An optional automatic page turner and page holder are respectively coupled to the housing and the image capturing system positioned opposite the slot where the book is to be placed. Automatic page turners are well known and available in the art. See U.S. 20050145097, U.S. 20050120601, SureTurn™ Advanced Page Turning Technology (Kirtas Technologies), the disclosures of which are incorporated herein by reference in their entirety. Pages may be turned in response to an automated signal from the transformation device or from a signal from a user. In addition, the device can be employed without an automated page turner, instead, relying on the user to turn pages of a book.
FIGS. 8A and 8B provide a further alternate configuration for the text capture device 100 of the present invention. The device of FIGS. 8A and 8B has two lenses 300 and 305 through which a camera 310 housed within the body 320 of the device may capture an image. In FIG. 8A , light 340 entering lens 300 is focused on the camera 310 aperture by mirror 330 . When the device captures an image through lens 305 , the mirror 330 is rotated out of the way (as indicated by dashed lines) and the light entering lens 305 (not shown) reaches the camera 310 aperture. The rotation may be simply accomplished by weighting the mirror and allowing gravity to rotate the mirror out of the way, and or a mechanical computer or user-controlled (override) mechanism for mirror movement may be employed. FIG. 8B shows an exemplary housing 320 for the text capture device of FIG. 8A . The housing of FIG. 8B has a raised region associated with the positioning of lenses 300 and 305 . The raised regions aid the user in quickly manually orienting the device to perform text capture operations through tactile cues.
Some of the figures accompanying the description of the present invention may include a logic flow. Although such figures presented herein may include a particular logic flow, it can be appreciated that the logic flow merely provides an example of how the general functionality as described herein can be implemented. Further, the given logic flow does not necessarily have to be executed in the order presented unless otherwise indicated. In addition, the given logic flow may be implemented by a hardware element, a software element executed by a processor, or any combination thereof.
Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. Examples of software may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. Determining whether an embodiment is implemented using hardware elements and/or software elements may vary in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints.
Some embodiments or aspects of embodiments may be implemented, for example, using a machine-readable or computer-readable medium or article which may store an instruction or a set of instructions that, if executed by a machine, may cause the machine to perform a method and/or operations in accordance with the embodiments. Such a machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware and/or software. The machine-readable medium or article may include, for example, any suitable type of memory unit, memory device, memory article, memory medium, storage device, storage article, storage medium and/or storage unit, for example, memory, removable or non-removable media, erasable or non-erasable media, writeable or re-writeable media, digital or analog media, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or disks, various types of Digital Versatile Disk (DVD), a tape, a cassette, or the like. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, encrypted code, and the like, implemented using any suitable high-level, low-level, object-oriented, visual, compiled and/or interpreted programming language.
Unless specifically stated otherwise, it may be appreciated that terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulates and/or transforms data represented as physical quantities (e.g., electronic) within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. The embodiments are not limited in this context.
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Embodiments of the invention provide devices and methods for capturing text found in a variety of sources and transforming it into a different user-accessible formats or medium. For example, the device can capture text from a magazine and provide it to the user as spoken words through headphones or speakers. Such devices are useful for individuals such as those having reading difficulties (such as dyslexia), blindness, and other visual impairments arising from diabetic retinopathy, cataracts, age-related macular degeneration (AMD), and glaucoma.
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TECHNICAL FIELD
The present invention relates generally to electric motor driver equipment and is particularly directed to an electrical circuit of the type which drives a DC servo motor. The invention is specifically disclosed as an interface circuit mated with a conventional stepper motor driver integrated circuit which allows this stepper motor driver IC to satisfactorily drive a DC servo motor at a significant cost reduction as compared to conventional DC servo motor driver IC's.
BACKGROUND OF THE INVENTION
Many ink jet printers use DC servo motors to drive the movable carriage that contains the ink jet printhead. DC servo motors have been used for many years for driving variable-speed devices, or for driving low power constant-speed devices that run from direct current, rather than from alternating current. However, stepper motors have become much more prevalent in many low-power applications for not only variable positioning devices, but also for variable-speed or constant-speed devices. Consequently, the integrated circuits that control stepper motors have become much less expensive, due to their much greater quantity of production, than integrated circuits that control DC servo motors.
While stepper motor driver circuits are less expensive than DC servo motor driver circuits, these devices are certainly not interchangeable with one another, and also their actual motor constructions are not interchangeable with one another. Stepper motors require control of two separate windings, and the current through each of these windings must be controllable in both directions by the driver circuitry. Moreover, stepper motors have been very useful for exact positioning applications, and have not completely replaced DC servo motors for certain applications, such as constant-speed drives using a low power DC power supply.
DC servo motors are typically driven with an electronic circuit that includes an "H-bridge" output driver stage, which is illustrated in FIG. 1 in some detail, and will be described in greater detail hereinbelow in the "Detailed Description." The branches of the circuit that make up the "H-bridge" comprise the four output transistors and the DC servo motor, which comprises the cross-bar of the "H." The method in which the four transistors are controlled determines whether or not the DC servo motor turns in its forward direction or in its reverse direction.
It would be commercially advantageous to be able to drive a DC servo motor while using a lower cost integrated circuit than the commonly-used L6202 integrated circuit, which is manufactured by SGS-Thomson Microelectronics.
SUMMARY OF THE INVENTION
Accordingly, it is a primary advantage of the present invention to provide a low-cost DC servo motor driver circuit that uses a readily available stepper motor driver integrated circuit chip.
It is another advantage of the present invention to provide a DC servo motor driver circuit that is substantially less expensive than those commonly available as standard conventional driver circuits.
It is a further advantage of the present invention to provide an interface circuit that operates with a stepper motor integrated circuit that is capable of driving a DC servo motor.
Additional advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention.
To achieve the foregoing and other advantages, and in accordance with one aspect of the present invention, an improved DC servo motor driver circuit is provided that is based upon a conventional integrated circuit that is readily available, but which is designed specifically for use with stepper motors. The current "Sense" line that is usually connected to a low value resistor is instead tied to DC common, or to ground. In addition, the "Comparator" input, which is usually connected to the current Sense line, is connected to a pulsing input signal that provides the comparators with an appropriate voltage to make the comparators believe that more current is required at the very times the remaining portions of the circuit are attempting to provide current to the DC servo motor. An RC circuit is provided at the "Pulse Time" input so that the monostable timer is properly triggered, which will in turn send an appropriate signal to the logic drivers that turn on the power transistors at the appropriate moments.
This DC servo motor driver, in an exemplary circuit, is used in a printer that uses a microprocessor to control an Application Specific Integrated Circuit (ASIC) which provides the proper logic signals to not only control the direction of the DC servo motor, but also to provide pulses of an appropriate frequency and duty cycle to emulate a pulse-width modulator, which acts as the main input control signal. The direction signal is connected to the "Phase" input, and the pulse-width modulated signal is provided to interface circuitry that drives the Comparator and Pulse Time inputs.
By appropriate use of signals generated by the ASIC, the output transistors in the H-bridge driver stage within the stepper motor driver integrated circuit are controlled so as to provide pulse-width modulated voltage pulses across the motor winding of the DC servo motor, such that this DC servo motor can operate exactly as if it were being driven by a dedicated DC servo motor driver circuit. The average current supplied over time to the DC servo motor is directly related to the duty cycle of the pulse-width modulated voltage pulses across its winding, which in turn is directly related to the duty cycle of the main input control signal. The ASIC is also interfaced to a optical encoder strip which provides closed-loop feedback control of the actual position of the printer's carriage.
Still other advantages of the present invention will become apparent to those skilled in this art from the following description and drawings wherein there is described and shown a preferred embodiment of this invention in one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description and claims serve to explain the principles of the invention. In the drawings:
FIG. 1 is a block diagram in partial schematic of a prior art DC servo motor driver circuit, as used with conventional printers.
FIG. 2 is a graph of some of the important physical parameters versus time of the prior art DC servo motor driver of FIG. 1.
FIG. 3 is another graph of other physical parameters versus time of the DC servo motor driver of FIG. 1.
FIG. 4 is a simplified schematic diagram of the electrical interface circuit used in creating the DC servo motor driver circuit of the present invention, which includes an integrated circuit designed to drive a stepper motor.
FIG. 5 is a block diagram in partial schematic of the DC servo motor driver of FIG. 4.
FIG. 6 is a diagram of some of the physical parameters versus time for the DC servo motor driver of FIG. 4.
FIG. 7 is another set of diagrams for other physical parameters versus time for the servo motor driver of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings, wherein like numerals indicate the same elements throughout the views.
Referring now to the drawings, FIG. 1 is a block diagram in partial schematic showing a prior art DC servo motor driver circuit 10, which includes an "H-bridge" output stage. This H-bridge comprises four field-effect transistors designated Q1, Q2, Q3, and Q4, as well as the field winding of the DC servo motor M1, designated by the reference numeral 12. Depending upon the combination of these field effect transistors (FET's), the servo motor 12 will either be at rest, or will turn in its forward or reverse direction.
The energization of DC servo motor 12 is controlled by pulses that actuate one pair or the other of the four transistors Q1-Q4. In the forward direction, a logic element and high voltage interface driver 14 is used to appropriately turn on transistors Q2 and Q3. In the reverse direction, a similar logic element and high-voltage interface driver 16 is used to turn on transistors Q1 and Q4. These forward and reverse drivers 14 and 16, respectively, are in turn controlled by an Application Specific Integrated Circuit (ASIC) 20, which in turn is controlled by a microprocessor 22.
This conventional DC servo motor driver 10 has been used in many ink jet printer circuits, and in such applications, a linear encoder 24 is used to provide a position feedback signal to ASIC 20. As is well known in the art, an exemplary linear encoder strip is placed along the path of the printer's ink jet cartridge carriage, and the encoder strip 24 preferably comprises a plastic strip with linearly spaced-apart dark lines that are optically read by a sensor that is mounted to the carriage. Such strips are typically used in classic DC servo motor drives, and it is preferred that there are two channels of pulses generated by the optical sensor, in which these pulses are in quadrature relationship to one another.
Each of the FET's Q1-Q4 includes a protective diode D1-D4, and the output terminals of an exemplary integrated circuit are depicted by the nodes 11 and 13 on FIG. 1. Such an exemplary integrated circuit for driving DC servo motors is a part number L6202, manufactured by SGS-Thomson Microelectronics. In the L6202 chip, the H-bridge transistors and diodes Q1-Q4 and D1-D4 are included, as well as the forward and reverse logic drivers 14 and 16.
The ASIC 20 and microprocessor 22 are typically provided as part of the printer control mechanism, and the linear encoder 24 provides a signal referred to as "X" to ASIC 20. In one exemplary ink jet printer manufactured by Lexmark International, Inc., the drive voltage Vcc is set at +30 volts DC, and the logic voltage used by the ASIC and microprocessor are at +5 volts DC.
FIG. 2 is a graph 30 showing the rotational velocity of the motor 12 versus time, and the instantaneous current through the motor winding versus time at the reference numeral 40. On the velocity graph 30, it can be seen that the initial velocity is zero, and that the velocity ramps up very quickly at a line 32. Once the velocity has reached its desired "constant" velocity, the DC servo motor driver 10 maintains that velocity, as can be seen at a line 34. After the ink jet carriage has traveled completely through its normal displacement, the velocity then decreases rather rapidly, as seen at a line 36.
On the current graph 40, the "time" axis directly corresponds along the horizontal to the time axis of the velocity graph 30. The motor current rises to an acceleration level due to inertial load, as indicated by a curve 42, until the motor reaches its desired constant velocity. The motor current settles down to a relatively straight line with a small amount of ripple, as seen at 44. A detail of this constant velocity stage of the motor current is depicted on FIG. 3, which corresponds to the small area of the chart 40 designated by the circle 48. Once the ink jet carriage has traveled through its complete displacement, the motor current quickly ramps down, as seen at a jagged line 46, after which the current stays at zero until the next movement of the carriage is desired.
The reason that the motor current appears to have a jagged or rippling effect is that the motor 12 is not provided with a pure DC signal, but instead is provided with pulses of current at a fairly high frequency of 20 kHz. The enlarged portion of the current curve from the circle 48 is illustrated in FIG. 3, which shows these 20 kHz pulses in greater detail.
FIG. 3 illustrates two graphs, one of the motor voltage in its forward direction versus time at the reference numeral 50, and the other of the motor current versus time at the reference numeral 70. In the graph 50, the motor pulses are seen at the reference numerals 52, 56, and 60. These are also called the "ON-time" pulses for the forward motor voltage. The corresponding "OFF-time" are designated by the reference numerals 54, 58, and 62. These pulses are directly across the motor's windings, i.e., across the outputs of the H-bridge circuit at nodes 11 and 13. On FIG. 3, the duty cycle is illustrated as being approximately 20%, which means that the ON-time pulses have a duration of approximately 10 μsec, and the OFF-time duration will be approximately 40 μsec, leading to a total duty cycle period of 50 μsec, for a corresponding frequency of 20 kHz.
The motor current values depicted on the graph 70 show that the current has already ramped up to its "maximum" value, which is not a true maximum possible current available from the DC power supply, but instead represents the maximum current required by the motor 12 to move the carriage at its desired constant velocity (as seen at 34 on FIG. 2). The horizontal time axis on the graph 70 directly corresponds to the horizontal time axis on the graph 50, and it thus can be seen that the ON-time current ramps at a linear rate, as seen at the reference numerals 72, 76, and 80. The corresponding OFF-time current decays at an exponential rate (which cannot really be seen at this scale), as depicted by the reference numerals 74, 78, and 82.
ASIC 20 generates the appropriate frequency pulses and provides the pulses directly to either the "Forward" driver 14 or the "Reverse" driver 16, as appropriate. These pulse-width modulated signals are then provided to the appropriate transistors Q1-Q4. In the forward direction, Q2 is turned on continuously, while Q3 is only turned on during the ON-time periods of the signal being transmitted by ASIC 20. Motor current is provided from the power supply when transistors Q2 and Q3 are both simultaneously turned ON by a positive pulse supplied by ASIC 20 to the input of Forward driver 14, and a low logic level supplied by ASIC 20 at the input of Reverse driver 16. It is preferred that the input to the Reverse driver 16 be kept at a low logic level while in the forward direction, thereby keeping Q2 continuously turned ON through its inverting buffer and keeping Q4 continuously turned OFF. Motor current "free wheels" through transistors Q1 and Q2 when the pulse at the input of Forward driver 14 is brought to a low logic state (i.e., between positive-going pulses).
To rotate the motor 12 in the reverse direction, the Reverse driver 16 provides positive pulses to the transistor Q4 having virtually the same duty cycle as positive pulses that are transmitted by ASIC 20 to the Reverse driver 16, which turns ON Q4 during those pulses. At the same time, transistor Q1 is continuously turned on through its inverting buffer when a low logic level is supplied by ASIC 20 at the input of Forward driver 14, for the same reasons as related above with respect to transistor Q2.
As in all typical DC servo motor drives, to achieve the constant velocity desired by the carriage of the ink jet printer, the duty cycle is varied depending upon the physical load of the carriage and its corresponding mechanical components, and also depending upon the voltage level of Vcc, which itself has an appreciable ripple, since in many systems that voltage supply is not regulated.
The interface circuitry of the present invention is illustrated in FIG. 4 as that interface circuitry is connected to an integrated circuit U1. U1 preferably is a part number TEA3718, manufactured by SGS-Thomson Microelectronics. This device is typically used as a stepper motor driver, however, in the present invention it is configured with appropriate interface circuitry for use in driving a DC servo motor "M2," designated by the reference numeral 114 on FIG. 4.
On FIG. 4, the block diagram for U1 shows the pin-outs and their designations, as according to the SGS-Thomson handbook. The logic level voltage for U1 is set at +5 volts DC, and this preferably is a regulated voltage. The motor drive voltage for U1 is preferably at +30 volts DC, which may not be very well regulated. The output pins on U1 are designated as "Out A" and "Out B", which also are the connections to the motor 114 via the electrical lines 110 and 112 on FIG. 4. Some of the other lines are attached either to +5 volts DC, or to DC common or ground. In particular, the "Sense" input at 116 is connected to DC common. If this integrated circuit were to be used with a stepper motor, the Sense line 116 would be connected to a low value resistor through which the motor current would flow, and the voltage across this resistor would be a direct indication of the current flow through the motor winding. In the present invention, however, it is preferred to directly tie this Sense line to ground or DC common.
The "Phase" input at 108 is provided with a "direction" input voltage signal, designated as V D , which is provided by an ASIC 152 (see FIG. 5). A pulse-width modulated signal V T is provided at 106 also from the same ASIC, and this signal is provided to an RC circuit (i.e., C1 and R4), and the resulting signal, designated as T in , is connected to the "Pulse Time" input at 104.
The same signal V T at 106 is also provided to a transistor circuit 100 which acts as a voltage inverter. This transistor circuit comprises resistors R1, R2, and R3 and a bipolar transistor Q5. The output of this transistor circuit is designated as V C , which is connected to the "Comparator" input at 102.
The pulse signal V T at 106 preferably is a pulse-width modulated signal running at 20 kHz, as indicated by the waveform graph 120. The output signal across the motor windings at 110 and 112 will also be a pulse-width modulated signal running at a higher voltage magnitude, as indicated by the waveform graph 122. While the input pulse voltage 120 runs at logic levels between zero volts and +5 volts DC, the output voltage across the motor 114 has a magnitude of either zero to +30 volts DC (in the forward direction) or zero to -30 volts DC (in the reverse direction).
FIG. 5 depicts a more complete circuit used in the present invention, which not only shows the ASIC and microprocessor, but also illustrates some of the internal components of U1. A microprocessor 150 is provided to control an ASIC 152, which in turn receives position information (as a signal "X") from a linear encoder 154. ASIC 152 also provides certain signals to U1 and to the interface circuitry. A signal V D is provided at 108 as a direction input signal, also referred to as the "Phase" in terminology used with the SGS-Thomson TEA3718 chip. A signal V T is provided at 106 to the RC network C1 and R4, and also as provided to the inverter circuit 100.
The signal V T is a pulse-width modulated signal, as indicated by the waveform pulses on FIG. 5. After this pulsed signal passes through the RC network, its waveform changes and is applied at 104 as a signal T in to a monostable timer 140, which is part of U1. The waveform of T in is depicted in greater detail on FIG. 7 at a graph 280. The pulsed signal V T , after inversion, is supplied as a signal V C at 102 to the voltage comparators 142, which are part of U1.
The other ASIC output signal is V D which is applied at 108 to U1. This signal is input to a non-inverting driver 130, which in turn supplies the signal to a bipolar transistor Q11. The same signal V D is applied to an inverting driver 132, which in turn provides a signal to another bipolar transistor Q12. Signal V D is also applied to a pair of logic circuits that also act as driver circuits, designated by the reference numerals 134 and 136. These two logic/drivers provide signals to control two more bipolar transistors Q13 and Q14. It will be understood that any type of solid-state switching device could be used in lieu of physical transistors without departing from the principles of the present invention, so long as the other type of switching device provided a sufficient current rating and could withstand the necessary voltage levels involved (e.g., +30 VDC).
The output of monostable timer 140 is also applied at 144 to both of the logic/driver circuits 134 and 136. In a similar manner, the output of the comparators 142 is also applied at 146 to the same two drivers 134 and 136.
It can be seen on FIG. 5 that, internal to U1, there is another H-bridge output drive circuit, which generally comprises the four transistors Q11-Q14, as well as the motor winding of motor 114, which is connected at the outputs 110 and 112. Whereas U1, as a chip type, typically drives one of the two motor coils of a stepper motor, in the present invention of FIG. 5, the motor 114 is a DC servo motor. To accomplish this feat, the H-bridge transistors Q11-Q14 must be able to provide the same type of signals as provided by the conventional H-bridge transistors Q1-Q4 depicted in the prior art circuit of FIG. 1. This is accomplished by the interface circuitry depicted on FIGS. 4 and 5.
When it is desired to drive the DC servo motor 114 in the forward direction, ASIC 152 will cause its output signal V D to change logic states to a Logic 1, which will turn on transistor Q11, and will turn off transistor Q12, by way of their respective logic circuits 130 and 132. For current to flow through the winding of motor 114, not only must Q11 be turned on, but also Q14 must be turned on. This is accomplished by driving the comparators with a signal V C at a Logic 0, which will fool the comparators into thinking that the "Sense" voltage has fallen below the desired level, which means that the motor requires more current. Therefore, the comparators 142 will output a signal at 146 to drive the two logic/drivers 134 and 136 into their ON-state. Simultaneously, the signal T in provides a +5 volt spike to the monostable timer 140, which then causes its "one-shot" circuit to output a pulse at 144, which then drives a signal to the two logic/driver circuits 134 and 136. The detail of the waveform at T in are provided on FIG. 7 at the graph 280.
Since V D is at Logic 1, the logic/driver 136 will turn its output on, whereas the logic/driver 134 does not turn its output on. Therefore, the output transistor Q14 is turned on, which allows current to flow in the forward direction through the motor 114. Transistor Q14 is held on for the entire duration of the ON-time of pulse signal V T , in the preferred embodiment illustrated on FIG. 5.
To rotate motor 114 in its reverse direction, the voltage must be reversed across the windings at 110 and 112. This is accomplished by the direction signal V D being held to its Logic 0 state, while at the same time causing the pulse-width modulated signal V T to be output to the monostable timer 140 and the comparator 142. With V D held at Logic 0, the transistors Q11 and Q14 will be held in their OFF states. Simultaneously, the opposite transistors Q12 and Q13 will be turned on at the appropriate times, since the direction signal is inverted by the logic gate 132 which drives transistor Q12, and the logic inside the logic/driver circuit 134 is opposite that of the logic/driver 136.
When the pulse-width modulated signal V T is now applied to the RC circuit and to the inverter 100, the comparators 142 will again be fooled into thinking that the "Sense" signal is calling for more current to flow through the motor winding. At the same time, the monostable timer 140 is caused to trigger a signal through its output at 144. When all of this occurs, the logic/driver circuit 134 turns on Q13. By this method, transistor Q 13 is turned on and off at the same duty cycle as the pulse signal V T .
FIGS. 6 and 7 show some details of the waveforms of certain signals that are generated by the preferred embodiment of the present invention illustrated on FIGS. 4 and 5. On FIG. 6, the motor velocity, motor current, and direction voltage are illustrated along a relatively long time base, which shows one entire carriage travel of the ink jet cartridge carriage. As seen along the bottom edge of FIG. 6, the ramp up time is approximately 40 milliseconds (msec), the constant velocity portion of the sweep is about 480 msec in duration, and the ramp down time is another 40 msec. The direction signal V D rises from zero volts to +5 volts DC during the entire forward movement of the carriage, as depicted by a curve 250. During this forward sweep, the motor velocity ramps up at 232, maintains a relatively constant velocity at the line 234, and ramps down at 236, on a graph 230. On a graph 240, the motor current is seen to rise to an inertial load peak at a curve 242, then remains at a relatively constant "maximum" constant speed current value that exhibits some ripple at 244, and then ramps down at 246 along a somewhat jagged line. Details of this rippled constant current are depicted on FIG. 7, which is a magnification of a portion of the line 244, as depicted by the circle 248.
On FIG. 7, the time scale has been greatly expanded so as to show some details of the pulses that operate at a much higher frequency of approximately 20 kHz. A graph 260 shows the pulse-width modulated output voltage V T from ASIC 152. As can be seen in this graph, the pulses are ON at a +5 volt DC level at the intervals 262, 266, and 270. The signal then shows OFF-times at the portions of the waveform at 264, 268, and 272. Each of the pulses on graph 260 exhibits a leading edge 274 and a trailing edge 276, and in the case of the voltage V T , the leading edge 274 is a rising edge and the trailing edge 276 is a falling edge, since the pulses being described at 262, 266, and 270 are positive-going pulses.
The comparator signal V C shows exactly the opposite logic on a graph 300. On this curve, during the ON-times for the transistors Q11-Q14, the voltage of V C is at Logic 0 during the time periods at 302, 306, and 310. During the OFF-times, the V C signal is at Logic 1 at 304, 308, and 312. Each of the pulses on graph 300 exhibits a leading edge 314 and a trailing edge 316, and in the case of the voltage V C , the leading edge 314 is a falling edge and the trailing edge 316 is a rising edge, since the pulses being described at 302, 306, and 310 are negative-going pulses.
It will be understood that, in the illustrated embodiment of FIGS. 4-7, the leading edge 274 of V T occurs in time substantially simultaneously with the leading edge 314 of V C , and therefore, is substantially synchronized with the comparator signal V C . Moreover, it will also be understood that, in the illustrated embodiment of FIGS. 4-7, the trailing edge 276 of V T occurs in time substantially simultaneously with the trailing edge 316 of V C . Of course, the initiating or driving signal in this circuit is the voltage signal V T .
A graph 280 on FIG. 7 depicts the waveform of the voltage signal T in . This is the signal that is shaped by the RC circuit which comprises C1 and R4, and which signal is used to trigger the monostable timer 140. It is preferred that this type of waveform signal be used to drive into the monostable timer input of the U1 integrated circuit, because without such a waveform, the triggering of the monostable timer could likely become unreliable. For example, if the "Pulse Time" input at 104 is held to ground, or is set to a +5 logic state continuously, then the monostable timer will not always successfully trigger every time the comparators receive a new pulse signal. Therefore, the RC circuit is used to provide a positive voltage spike at the beginning of the ON-times for each period of the duty cycle of the pulse-width modulated signal V T .
It additionally is preferable that the time constant of this RC network is very short, so that the voltage level exponentially decays to zero (or near-zero) well in advance of the falling edge of the signal V T . This can be easily seen on the graphs 260 and 280, such that the trailing edge 296 of the waveform of the voltage signal 282 falls to zero well in advance of the falling edge of the pulse signal 262. This type of waveform will occur for each of the periods of the pulse-width modulated signal, as illustrated at 286 and 290. Each of the above-described pulses on graph 280 exhibits a leading edge 294 and a trailing edge 296, and in the case of the voltage T in , the leading edge 294 is a rising edge and the trailing edge 296 is a falling edge, since the pulses being described at 282, 286, and 290 are positive-going pulses.
It will be understood that, in the illustrated embodiment of FIGS. 4-7, the leading edge 274 of V T occurs in time substantially simultaneously with the leading edge 294 of T in . Moreover, it will also be understood that, in the illustrated embodiment of FIGS. 4-7, the trailing edge 276 of V T preferably occurs in time well after (within the respective time frame of the graphs of FIG. 7) the trailing edge 296 of T in falls below a Logic 0 level for whatever type of logic gates are used at the Pulse Time input signal 104 of U1. If the frequency of T in is 20 kHz, and if the illustrated duty cycle on FIG. 7 is approximately 20%, the ON-time pulses (e.g., pulses 262 and 302) will have a duration of approximately 10 μasec, and the OFF-time duration (e.g., at 264 and 304) will be approximately 40 μsec, leading to a total duty cycle period of 50 μsec.
With the circuitry depicted on FIGS. 4 and 5, the signal T in will also exhibit a small negative-going spike at the end of the ON time for each pulse. This is depicted at the negative spikes and exponential decays at 284, 288, and 292.
The resultant motor current is depicted on a graph 320. Since this graph is taken from the circle 248 which occurs during the constant velocity travel of the carriage, the motor current has already reached its preferred value to maintain this motor speed. This current is designated as "I MAX ," which is not truly the maximum current that can be supplied through this driver circuit, but is merely being designated as such to illustrate this being the normal maximum current during the constant velocity phase of the movement of the carriage. On graph 320, the instantaneous current increases linearly during each ON-pulse of the signal V T , which is illustrated at the lines 322, 326, and 330. During the corresponding OFF-times of V T , the current will exponentially decay, as illustrated at 324, 328, and 332. It should be noted, however, that the exponential decay cannot be readily discerned at this high frequency because of the relatively long time constant involved with the motor inductance.
By use of the interface circuitry depicted on FIGS. 4 and 5, an integrated circuit normally used to drive a stepper motor can be "fooled" into driving a DC servo motor with complete satisfaction. The comparator signal V C at 102 is actually the signal that causes the output drive transistors to appropriately turn on and off. Since the output of the comparators 142 depends upon whether nor not the comparators believe that a sufficient amount of current is being supplied to the motor, then causing the output of the comparators to be clamped to a Logic 0 will cause the output transistors to turn on, by causing the comparators to believe that more current is needed for the motor 114. Alternatively, causing the comparators output at 146 to jump to a Logic 1 state will turn off the output transistors, because the comparators now believe that a sufficient amount of current has been supplied to the motor 114.
For an exemplary ink jet printer manufactured by Lexmark International, Inc., a 10% duty cycle or less is all that is required during the constant velocity phase of the carriage movement, given that the drive voltage is at +30 volts DC. In such an exemplary printer, the wattage consumed by the motor during the constant velocity phase is in the range of three (3) to five (5) Watts. During the acceleration phase of the carriage, the power consumed by the motor is in the range of twelve (12) to twenty (20) Watts. The duty cycle during this acceleration phase typically is a maximum of about 67%.
It will be understood that various minor changes to the interface circuitry could be made without departing from the principles of the present invention. Furthermore, other types of motor driver circuitry could be used to drive a DC servo motor which also may require a similar interface circuit for proper operation with a DC servo motor, without departing from the principles of the present invention.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and 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.
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An improved DC servo motor driver circuit is provided that is based upon a readily available conventional stepper motor driver integrated circuit (IC). The IC's current "Sense" line that is usually connected to a low value resistor is instead tied to DC common or to ground. The IC's "Comparator" input, which is usually connected to the current Sense line, is connected to a pulsing input signal that provides the comparators with an appropriate voltage to make the comparators believe that more current is required at the very times the remaining portions of the circuit are attempting to provide current to the DC servo motor. An RC circuit is provided at the IC's "Pulse Time" input so that the monostable timer is properly triggered. An ASIC provides the proper logic signals to not only control the direction of the DC servo motor, but also to provide pulses of an appropriate frequency and duty cycle to emulate a pulse-width modulator. The direction signal is connected to the "Phase" input, and the pulse-width modulated signal is provided to interface circuitry that drives the Comparator and Pulse Time inputs. The output transistors in an H-bridge driver stage within the stepper motor driver IC are controlled so as to provide pulse-width modulated voltage pulses across the motor winding of the DC servo motor, such that this DC servo motor can operate exactly as if it were being driven by an integrated circuit that was specifically designed to act as a DC servo motor driver circuit. The average current supplied over time to the DC servo motor is directly related to the duty cycle of the pulse-width modulated voltage pulses across its winding, which in turn is directly related to the duty cycle of the main input control signal.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application No. 11/589,648, filed Oct. 30, 2006, and claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/732,265, filed Oct. 31, 2005, the disclosures of which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to orthopedic medicine, and more particularly to systems and methods for restricting relative motion between vertebrae.
[0003] Unfortunately millions of people experience back pain, and such is not only uncomfortable, but can be particularly debilitating. For example, many people who wish to participate in sports, manual labor, or even sedentary employment are unable to do so because of pains that arise from motion of or pressure on the spinal column. These pains are often caused by traumatic, inflammatory, metabolic, synovial, neoplastic and degenerative disorders of the spine.
[0004] In a normal spinal column, intervertebral discs that separate adjacent vertebrae from each other serve to provide stiffness that helps to restrain relative motion of the individual vertebrae in flexion, extension, axial rotation, and lateral bending. However, a damaged disc may provide inadequate stiffness along one or more modes of spinal motion. This inadequate stiffness may result in excessive relative vertebral motion when the spine is under a given load, as when the patient uses the muscles of the back. Such excessive relative motion may cause further damage to the disc, thereby causing back pain and ultimately, requiring replacement of the disc and/or other operations to decompress nerves affected by central, lateral or foraminal stenosis.
[0005] Heretofore, some stabilization devices have been proposed to restrict, but not entirely prevent, relative motion between adjacent vertebrae. These devices often contain linear springs that are too long to be easily positioned between adjacent vertebrae. Thus, they are often impossible to implant on motion segments where there is a short pedicle-to-pedicle displacement. Furthermore, known spinal implants typically have components that are either flexible, allowing limited relative motion between adjacent vertebrae, or rigid, providing fusion between vertebrae. Thus, they do not provide for interchangeability between flexible and rigid components. Accordingly, symptoms that would normally indicate stabilization and fusion of adjacent motion segments cannot be adequately treated, and vice versa. In other words, revision of an implant to provide fusion in place of stabilization is typically not feasible. Finally, many devices, when implanted in multiple levels along the spine, do not flexibly follow the natural curvature of the spine. Such devices may therefore cause discomfort, or restrict spinal motion in an unpredictable and unnatural manner.
[0006] Therefore, there exists a need for a system and method which corrects the above-noted shortcomings and allows for dynamic vertebral stabilization to restore normal movement and comfort to a patient.
SUMMARY OF THE INVENTION
[0007] A first aspect of the present invention is a stabilization system for controlling relative motion between a first vertebra and a second vertebra. In accordance with this first aspect, on embodiment stabilization system may include a first stabilizer having a first coupling adapted to be attached to a first anchoring member, a second coupling adapted to be attached to a second anchoring member and a resilient member configured to be coupled to the first and second couplings to transmit resilient force between the first and second couplings, the resilient member including a planar spring, wherein at least a portion of the planar spring flexes out-of-plane in response to relative motion between the vertebrae.
[0008] In other embodiments of the first aspect, the first stabilizer may further include a casing including a hollow first member and a hollow second member, wherein the resilient member is positioned within a cavity defined by engagement of the first and second hollow members. The resilient member is may also be positioned inside the casing such that the casing limits relative motion of the vertebrae by limiting deflection of the planar spring. The system may also include the first anchoring member and the second anchoring member, where the first and second anchoring members include a yoke polyaxially coupled to a fixation member implantable in a portion of either the first or second vertebra. The system may also include a first rigid connector including first and second couplings adapted to be attached to one of the first and second anchoring members, wherein the couplings are substantially rigidly connected together. In other embodiments, the path followed by the planar spring may be generally spiral-shaped, wherein the planar spring includes a central portion attached to the first coupling and a peripheral portion attached to the second coupling. The first stabilizer may further include a first articulation component configured to articulate to permit polyaxial relative rotation between one of the first or second couplings. The first articulation component may include a semispherical surface and a socket within which the semispherical surface is rotatable to permit polyaxial motion between the resilient member and the first anchoring member. The resilient member may be coupled to the first and second couplings such that the resilient member is able to urge the first and second couplings to move closer together and is also able to urge the couplings to move further apart.
[0009] The stabilization system may include a second component comprising a third coupling and a fourth coupling, wherein the third coupling is adapted to be attached to the first anchoring member such that the first anchoring member is capable of simultaneously retaining the first and third couplings. The second component may be a rigid connector, wherein the third and fourth couplings are substantially rigidly connected together, or the second component may be a second stabilizer comprising a second resilient member configured to exert resilient force between the third and fourth couplings.
[0010] Another aspect of the present invention is another stabilization system for controlling relative motion between a first vertebra and a second vertebra. In accordance with this second aspect, the stabilization system may include a first stabilizer having a first coupling adapted to rest within a yoke of a first anchoring member, a second coupling adapted to rest within a yoke of a second anchoring member, a resilient member coupled to the first and second couplings to transmit resilient force between the first and second couplings, the resilient member including a planar spring, wherein at least a portion of the planar spring flexes out-of-plane in response to relative motion between the vertebrae and a first articulation component configured to articulate to permit relative rotation between the first stabilizer and one of the first or second couplings.
[0011] Still another aspect of the present invention is a stabilization system for controlling relative motion between a first vertebra and a second vertebra. The stabilization system according to this aspect may include a first stabilizer having a first coupling adapted to be attached to a first anchoring member, a second coupling adapted to be attached to a second anchoring member, a resilient member configured to be coupled to the first and second couplings to transmit resilient force between the first and second couplings, the resilient member including a planar spring, wherein at least a portion of the planar spring flexes out-of-plane in response to relative motion between the vertebrae, a first articulation component configured to articulate to permit relative rotation between the first and second couplings and a first rigid connector including third and fourth couplings adapted to be attached to the first and second anchoring members, wherein the third and fourth couplings are substantially rigidly connected together.
[0012] Yet another aspect of the present invention is a method for controlling relative motion between a first vertebra and a second vertebra. In accordance with this aspect, the method may include the steps of positioning a planar spring of a first stabilizer attaching a first coupling of the first stabilizer to the first vertebra and attaching a second coupling of the first stabilizer to the second vertebra, wherein, after attachment of the couplings to the vertebrae, the planar spring is positioned to transmit resilient force between the vertebrae via flexure of at least a portion of the planar spring out-of-plane.
[0013] Yet another aspect of the present invention is another method for controlling relative motion between a first vertebra and a second vertebra. In accordance with this aspect, the method may include selecting a component selected from the group consisting of a first stabilizer and a first rigid connector, wherein the first stabilizer comprises a first coupling, a second coupling adapted to be attached to a second anchoring member secured to the second vertebra, a resilient member configured to transmit resilient force between the first and second couplings, and a first articulation component configured to articulate to permit relative rotation between the first and second couplings, wherein the first rigid connector comprises a first coupling and a second coupling substantially rigidly connected to the first coupling, attaching a first coupling of the selected component to a first anchoring member secured to the first vertebra and attaching a second coupling of the selected component to a second anchoring member secured to the second vertebra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A more complete appreciation of the subject matter of the present invention and the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which:
[0015] FIG. 1 is a perspective view of a dynamic stabilization assembly according to one embodiment of the invention.
[0016] FIG. 2 is an enlarged perspective view a stabilizer of the dynamic stabilization assembly of FIG. 1 .
[0017] FIG. 3 is an exploded perspective view of the stabilizer of FIG. 2 .
[0018] FIG. 4 is a further exploded perspective view of the stabilizer of FIG. 2 .
[0019] FIG. 5 is a partially exploded perspective view of the stabilizer of FIG. 2 having two end caps.
[0020] FIG. 6 is a perspective view of the stabilizer of FIG. 2 , illustrating attachment of one end cap to an end coupling.
[0021] FIG. 7 is a perspective view of the stabilizer of FIG. 2 with attached end caps.
[0022] FIG. 8 is a partially exploded perspective view of the dynamic stabilization assembly of FIG. 1 .
[0023] FIG. 9 is a perspective view of two of the stabilizers of FIG. 2 , placed end to end, with two end caps being detached therefrom.
[0024] FIG. 10 is a perspective view of two of the stabilizers of FIG. 2 , placed end to end, with two end caps being attached thereto.
[0025] FIG. 11 is a perspective view of two stabilizers of FIG. 2 , placed end to end, illustrating the coupling of the ends of the stabilizers to each other.
[0026] FIG. 12 is a perspective view of the stabilizer of FIG. 2 , coupled end-to-end with a second stabilizer for multi-level vertebral stabilization.
[0027] FIG. 13 is a perspective view of the two stabilizers of FIG. 12 , illustrating how the articulation components may be used to provide an overall curvature to the assembled modules.
[0028] FIG. 14 is a perspective view of the stabilizer of FIG. 2 , coupled end-to-end with a rigid connector and an end cap for single level vertebral joint stabilization with joint immobilization at an adjacent level.
[0029] FIG. 15 is an exploded perspective view of the stabilizer and rigid connector of FIG. 14 , illustrating the coupling of the stabilizer and the rigid connector to each other.
[0030] FIG. 16 is a perspective view of the stabilizer and rigid connector of FIG. 14 , illustrating how the articulation components may be used to provide an overall curvature to the assembled modules.
[0031] FIG. 17 is a perspective view of another dynamic stabilization assembly according to an alternative embodiment of the invention.
[0032] FIG. 18 is an enlarged perspective view of a stabilizer and end couplings of the dynamic stabilization assembly of FIG. 17 .
[0033] FIG. 19 is an exploded perspective view of the stabilizer of FIG. 18 .
[0034] FIG. 20 is an exploded perspective view of the stabilizer and end couplings of FIG. 18 .
[0035] FIG. 21 is a partially exploded perspective view of the dynamic stabilization assembly of FIG. 17 .
[0036] FIG. 22 is a perspective view of an overhung stabilizer and articulating component of an overhung dynamic stabilization assembly designed for shorter pedicle-to-pedicle displacements.
[0037] FIG. 23 is an exploded perspective view of the overhung stabilizer of FIG. 22 .
[0038] FIG. 24 is a partially exploded perspective view of an overhung dynamic stabilization assembly including the components of FIG. 22 .
[0039] FIG. 25 is another partially exploded perspective view of the overhung dynamic stabilization assembly of FIG. 24 .
[0040] FIG. 26 is a perspective view of a fully assembled overhung dynamic stabilization assembly of FIG. 24 .
[0041] FIG. 27 is a perspective view of the dynamic stabilization assembly including the stabilizer of FIG. 22 , along with the overhung stabilization assembly of FIG. 24 .
[0042] FIG. 28 is an exploded perspective view of the dynamic stabilization assembly of FIG. 27 .
[0043] FIG. 29 is a further exploded perspective view of the dynamic stabilization assembly of FIG. 27 .
DETAILED DESCRIPTION
[0044] The present invention relates to systems and methods for stabilizing the relative motion of spinal vertebrae. Those of ordinary skill in the art will recognize that the following description is merely illustrative of the principles of the invention, which may be applied in various ways to provide many different alternative embodiments. This description is understandably set forth for the purpose of illustrating the general principles of this invention and is not meant to limit the inventive concepts in the appended claims.
[0045] Referring to FIG. 1 , one embodiment of a single level dynamic stabilization system 10 is shown. The dynamic stabilization system 10 preferably includes a stabilizer 12 , a pair of fixation members 14 , a pair of yokes 16 securable to the fixation members 14 , and a pair of set screws 18 . The fixation members 14 , yokes 16 , and set screws 18 may be any of a variety of types known and available in the art, or may optionally be specially designed for operation with the stabilizer 12 . Each fixation member 14 with its corresponding yoke 16 and set screw 18 provides an anchoring member 19 designed to anchor the stabilizer 12 to a pedicle or other portion of a vertebra (not shown). In the embodiments described and illustrated herein, the fixation members 14 are represented as pedicle screws. However, they could also be other types of screws fixed to other parts of the vertebrae, pins, clips, clamps, adhesive members, or any other device capable of anchoring the stabilizer to the vertebrae. Additionally, each yoke 16 may be unitarily formed with a fixation member 14 as illustrated herein, or each yoke 16 may be a separate entity and be polyaxially securable to a fixation member 14 .
[0046] The stabilizer 12 is illustrated alone in FIG. 2 . As shown in that figure, stabilizer 12 includes a central spring casing 22 , and a short arm 26 extending from the spring casing 22 on one side to an articulation component 24 . On the opposite side, a longer arm 27 extends from the spring casing 22 to another articulation component 25 . An end coupling 28 is also preferably located on the outside of each articulation component 24 , 25 . It is noted that the particular construction of stabilizer 12 depicted in FIG. 2 may vary. For example, the short arm 26 and longer arm 27 may be flipped to opposite sides.
[0047] Referring to FIG. 3 , an exploded view of the stabilizer 12 is shown, thereby illustrating the inner components of the stabilizer. For example, a planar spring 20 is shown encased within the spring casing 22 . The planar spring 20 is preferably coiled in a planar spiral-like shape and has a threaded inner ring surface 30 and an outer ring surface 32 . In addition, the spring casing 22 is made up of two concentric hollow members, an inner hollow member 40 and an outer hollow member 42 , with the planar spring 20 being disposed within the inner hollow member 40 . A circular bore 44 occupies the center of the inner hollow member 40 , creating a round opening from an inside surface 46 to an outside surface 48 . A protruding circular lip 49 may also surround the bore 44 where it exits the outside surface 48 . An inner wall of the lip 49 is preferably threaded. Similarly, a circular bore 54 occupies the center of the outer hollow member 42 , creating a round opening from an inside surface 56 to an outside surface 58 . A protruding circular lip 59 may also surround the bore 54 where it exits the outside surface 58 .
[0048] Shown adjacent to the inner hollow member 40 is the short arm 26 , which has a threaded outer surface 76 on the end closest to the inner hollow member 40 . This end terminates at a flat end 36 . Both surface 76 and flat end 36 are best shown in FIG. 4 . On the opposite end of the short arm 26 is the articulation component 24 , which terminates at the end coupling 28 . Adjacent to the outer hollow member 42 is the long arm 27 , which has a threaded terminal segment 78 on the end closest to the outer hollow member 42 . The terminal segment terminates at a flat end 37 (best shown in FIG. 4 ). On the opposite end of the long arm 27 is the articulation component 25 , which terminates at the end coupling 28 .
[0049] When assembled, the short arm 26 fits inside the bore 44 of the inner hollow member 40 . The threads on the outer surface 76 engage with the threads on the inner wall 52 , thereby securing the pieces together. As mentioned above, the planar spring 20 fits inside the inner hollow member 40 . In addition, the long arm 27 fits through the bore 54 of the outer hollow member 42 , with the threaded terminal segment 78 engaging the threaded inner ring surface 30 of the planar spring 20 . The inner hollow member 40 fits concentrically within the outer hollow member 42 , with the planar spring 20 also being disposed inside. Inside of the hollow members 40 , 42 , the flat ends 36 , 37 of the arms 26 , 27 are preferably adjacent to one another but not touching.
[0050] When assembled with the hollow members 40 , 42 and the arms 26 , 27 , the planar spring 20 can, if acted upon, flex out of the plane within which it is coiled. When the longer arm 27 , to which the planar spring 20 is engaged, moves toward or away from the short arm 26 , the spiral-like shape of the planar spring 20 preferably extends out of its plane. When the longer arm 27 returns to its original position, the planar spring 20 also preferably recoils back to its plane. During this extension and recoil, the inside surface 46 of the inner hollow member 40 , and the inside surface 56 of the outer hollow member 42 act as barriers to limit the movement of the planar spring 20 .
[0051] Use of the planar spring 20 , as opposed to a longer helical spring, keeps the overall length of the stabilizer 12 relatively short. In alternative embodiments, a planar spring according to the invention need not have a spiral-like shape, but can rather be a cantilevered leaf spring, a flexible disc, or the like. Further, in other alternative embodiments, a planar spring need not be used; rather, a different type of spring or a conventional helical spring may be used.
[0052] FIG. 4 illustrates the articulation components 24 , in an exploded view. As is mentioned above, the articulation component 24 is located adjacent to and couples with the inner hollow member 40 , and the articulation component 25 is located adjacent to and couples with the outer hollow member 42 . Each articulation component 24 , 25 preferably comprises a semispherical surface 60 , a cup 62 , which are both enclosed by the end coupling 28 . The cup 62 is preferably dish shaped, with a cylindrical support wall 64 and two ends. On one end of the cup 62 is a depression 66 , and on the opposite side of the cup 62 is a flat end 68 . The semispherical surface 60 preferably has a round side 70 which rotatably fits inside the depression 66 , so that each of the articulation components 24 , 25 thus takes the form of a ball-and-socket joint. The opposite side of each semispherical surface 60 is a connecting side 72 which narrows into a neck 74 . The neck 74 preferably widens into either the short arm or the long arm 27 , which extends away from the semispherical surface 60 on the opposite side from the round side 70 . As is discussed above, the outer wall 76 of the short arm 26 is threaded, as is the terminal segment 78 of the long arm 27 . In alternative embodiments, articulation components may be omitted, or may be formed by any other type of mechanical joints known in the art.
[0053] The end coupling 28 has a support wall 102 which forms the outer sides of the cup, and a base 104 . A circular hole 106 occupies the center of the base 104 , and where the edge of the hole 106 meets the base 104 , a circular rim 108 preferably surrounds the hole 106 . The inside diameter of the rim 108 is preferably less than the diameter of the semispherical surface 60 of the articulation components 24 and 25 , so that when assembled the semispherical surface 60 will fit into the end coupling 28 but not be capable of passing through the hole 106 . At the opposite end from the base 104 , the support wall 102 terminates in a flat edge 110 . Protruding from the edge 110 in the same plane as the support wall 102 , such that they form continuations of the support wall 102 , is a plurality of irregularly shaped teeth 112 . Between each tooth 112 and the adjacent tooth is a notch 114 .
[0054] When assembled, the round side 70 of each semispherical surface 60 rotatably rests in the depression 66 of the cup 62 , and the arm 26 or 27 extends away from the joining side 72 of the semispherical surface 60 . The generally cup-shaped end coupling 28 fits over each semispherical surface, arm and cup assembly. Each arm 26 , 27 extends from its semispherical surface 60 through its respective hole 106 . As described above, the arms then extend into the spring casing 22 , the long arm 27 connecting to the planar spring 20 and the short arm 26 connecting to the inner hollow member 40 . Rotation of either semispherical surface 60 results in movement of its arm 26 , 27 . When the short arm 26 moves, the flat end 37 of the opposite arm 27 may optionally contact the flat end 36 of the short arm 26 to acts as a stop to limit excessive movement. Similarly, when the long arm 27 moves, the flat end 36 of the opposite short arm 26 may stop excessive movement via contact with the flat end 37 of the long arm 27 . Thus the articulation components 24 , 25 secure the arms 26 , 27 in a rotatable manner to the spring casing 22 to permit the stabilizer 12 to obtain a variable curvature.
[0055] The assembled stabilizer 12 can be rotated into locking engagement with end caps or end couplings of other stabilizers for multi-level application. In fact, FIG. 5 illustrates one coupled stabilizer 12 , having a coupled end cap 120 and an uncoupled end cap 120 . Each end cap 120 preferably has a general cup-shape, much like each end coupling 28 . Each end cap 120 preferably includes a support wall 122 which forms the outer sides of the cup, and a solid base 124 which forms the bottom of the cup. The inside diameter of the end cap 120 is sized to fit around either arm 26 , 27 . At an opposite end from the base 124 , the support wall 122 terminates in a flat edge 130 . Protruding from the edge 130 in the same plane as the support wall 122 , such that they form continuations of the support wall 122 , are a plurality of irregularly shaped teeth 132 . Between each tooth 132 and the adjacent tooth is a notch 134 .
[0056] Referring to FIG. 6 , an end cap 120 is illustrated in partial engagement to a stabilizer 12 . When an end cap 120 is to be attached to an end coupling 28 , the end cap 120 is preferably lined up with the end coupling 28 so that the teeth 112 , 132 are pointed toward one another. The end cap 120 is then rotated and moved toward the end coupling 28 so that the teeth 132 fit into the notches 114 , while the teeth 112 fit into the notches 134 . When the teeth 112 , 132 are fully seated in the notches 114 , 134 such that the teeth 132 touch the edge 110 and the teeth 112 touch the edge 130 , the end cap 120 is further rotated until the teeth 112 , 132 interlock with each other and the end cap 120 is locked in place. A stabilizer 12 with two end caps 120 each fully engaged on opposite ends of the stabilizer 12 is depicted in FIG. 7 . In this depiction, the end caps 120 have been fully rotated so that the teeth 132 of the end caps 120 are interlocked with the teeth 112 of both end couplings 28 .
[0057] FIG. 8 shows an exploded view of the dynamic stabilization system 10 with a fully assembled stabilizer 12 , two anchoring members 19 with yokes 16 and fixation members 14 , and two set screws 18 . In this design, each fixation member 14 preferably has a pointed end 140 which aids in screwing the member into a corresponding vertebra when implanted. The opposite end of the fixation member 14 is preferably unitarily formed with a U-shaped yoke 16 , so that the bottom of the U is a head 142 of the fixation member 14 . Each yoke 16 has two curved opposing support walls 144 . Alternating between the support walls 144 are two opposing gaps 146 , which form a cavity 148 therebetween that occupies the interior of the yoke 16 . The inner surfaces 150 of the support walls 144 are also preferably threaded to engage a set screw 18 .
[0058] According to the embodiment depicted, in use, the stabilizer 12 is inserted into the yokes 16 of two anchoring members 19 whose fixation members 14 have previously been anchored in the pedicles, or other portion, of the corresponding vertebrae. The stabilizer 12 is laid lengthwise into the yokes 16 such that the long axis of the stabilizer 12 is perpendicular to the long axes of the fixation members 14 , and so that the spring casing 22 lies between the anchoring members 19 . Each end coupling 28 /end cap 120 pair preferably rests on the head 142 within the cavity 148 . Each end cap preferably occupies the gaps 146 , and the two articulation components 24 , 25 lie adjacent to, but outside of, the two interior gaps 146 .
[0059] The end couplings 28 and attached end caps 120 are preferably secured within the yokes 16 of the anchoring members 19 through the use of the set screws 18 . One set screw 18 is screwed into the top of each yoke 16 so that its threads engage with the threaded inner surfaces 150 of the support walls 144 . The set screws 18 are then tightened to hold the stabilizer 12 in place. As described above, an alternative embodiment of the invention includes yokes 16 which are separate entities from the fixation members 14 , and are polyaxially securable to the fixation members 14 . If such separate polyaxially securable yokes 16 are included, tightening of the set screws 18 may also press the end couplings 28 and end caps 120 against the heads 142 of the fixation members 14 , thereby restricting further rotation of the polyaxially securable yokes 16 with respect to the fixation members 14 to secure the entire assembly. Those of ordinary skill in the art would readily recognize this operation.
[0060] Referring to FIG. 9 , two assembled stabilizers 12 are illustrated positioned end-to end with two end caps 120 positioned at the outer ends of the stabilizers 12 . Two stabilizers 12 may be interlocked with each other end-to-end and implanted when it is desirable to stabilize the relative motion of three adjacent vertebrae. FIG. 10 depicts a similar assembly, with two stabilizers 12 being illustrated end-to-end, and one end cap 120 being secured to each outer end coupling 28 in a similar fashion to that previously depicted in FIG. 7 . On the inner ends of each stabilizer 12 , the teeth 112 of each end coupling 28 are aligned to fit into the notches 114 of the facing end coupling 28 . FIG. 11 depicts the two stabilizers 12 in an end-to-end fashion and partially interlocked together. The teeth 112 of each facing end coupling 28 are in the notches 114 of the opposite end coupling 28 , and the stabilizers 12 have been partially turned so that the teeth 112 are partially interlocked. In FIG. 12 , the two stabilizers 12 are shown completely interlocked end-to-end. The end couplings 28 of the two stabilizers 12 are rotated into locking engagement with each other and an end cap 120 is locked onto each unoccupied external end coupling 28 . The entire dynamic stabilization assembly has four articulation components 24 , 25 , which will permit considerable differentiation in orientation between the three fixation members 14 that would be used to attach the stabilizers 12 to three adjacent vertebrae (not shown). In fact, in FIG. 13 , two interlocked stabilizers 12 are illustrated with the articulation components 24 , 25 in an articulated position so that the stabilizers 12 no longer lie in a straight line, but instead the multi-level dynamic stabilization assembly approximates a curve. This enables the assembly to conform to the desired lordotic curve of the lower spine or to other spinal curvatures, such as those caused by or used to correct scoliosis. Additional levels can be added if desired.
[0061] Referring to FIG. 14 , a stabilizer 12 is depicted secured end-to-end to a rigid connector 160 to provide dynamic stabilization across one level, and posterior immobilization and/or fusion across the adjacent level. The rigid connector 160 has a rod 162 and an end coupling 164 . The end coupling 164 is toothed and notched so that it may engage the end coupling 28 on the stabilizer 12 . This is not unlike the other couplings discussed above. In addition, and like that discussed above, the rod 162 may be secured in the yoke 16 of a fixation member 14 with a set screw 18 . Similarly, the interlocked end coupling 164 /end coupling 28 combination may be secured in the yoke 16 of an anchoring member 19 in a manner similar to the previously described securing of the end couplings and end caps. Additional rigid connectors 160 or stabilizers 12 with associated anchoring members 19 can be added if additional levels are desired.
[0062] FIG. 15 depicts an exploded view of the system depicted in FIG. 14 , having one stabilizer 12 , an end cap 120 , and one rigid connector 160 . The end coupling 164 has teeth 166 protruding from one end, and notches 167 between the teeth. When the rigid connector 160 is attached to the stabilizer 12 , the teeth 166 of the end coupling 164 fit into the notches 114 of the end coupling 28 . Simultaneously, the teeth 112 of the end coupling 28 fit into the notches 167 of the end coupling 164 . The stabilizer 12 and the rigid connector 160 are rotated in opposite directions so that the teeth 112 , 166 interlock and the stabilizer 112 and the rigid connector 160 are locked together. The end cap 120 is interlocked onto the remaining open coupling 28 of the stabilizer 12 as previously described. FIG. 16 depicts one stabilizer 12 interlocked with a rigid connector 160 and an end cap 120 , and in a position with components 24 , 25 being articulated to allow the assembly to approximate a curve.
[0063] Thus, like the above described systems, dynamic stabilization across one level and posterior immobilization and/or fusion across the adjacent level may be accomplished while simultaneously following the desired curvature of the spine. In some cases, it may be desirable to allow immobilization and/or fusion across one level, and dynamic stabilization across the adjacent level on each end. In such a case, a rigid connector 160 with an end coupling 164 at each end could be used, allowing a stabilization module 12 to couple to each end of the rigid connector 160 .
[0064] Referring to FIG. 17 , an alternative embodiment of a stabilization system 168 is depicted. In this system, a stabilizer 170 is secured to two anchoring members 19 . As in the previous embodiment, the anchoring members 19 each preferably include two yokes 16 connected with two fixation members 14 , and two set screws 18 are preferably used to hold the stabilizer 170 in place.
[0065] As seen in FIG. 18 , the stabilizer 170 has a spring casing 172 and two articulation components 174 , 175 . A two-piece end housing 178 also preferably extends from either articulation component 174 , 175 . As shown in FIG. 19 , the spring casing 172 preferably houses a planar spring 180 . The planar spring 180 has a first side 182 and a second side 183 . Extending from the first side 182 is an arm 184 which narrows into a neck 186 and terminates in a semispherical surface 188 . The spring casing 172 has an outer hollow member 190 and an inner hollow member 192 . The inner hollow member 192 is of a shallow dish shape, and has a circular plate 194 which forms the base of the hollow member, with a threaded outer rim 196 which encircles the outside of the plate 194 . An inner rim 198 encircles a round hole 200 in the center of the plate 194 .
[0066] Similarly, the outer hollow member 190 is of a deep dish shape with an interior cavity 202 . It has a circular plate 204 which forms the base of the hollow member, and a support member 206 which forms the side wall of the hollow member. An inner surface 208 of the support member 206 is threaded, but a neck 210 extends from the outside of the plate 204 and terminates in a semispherical surface 212 . This latter element is different from both inner hollow member 192 and that which is included in the above described embodiments of the present invention.
[0067] When assembled, the planar spring 180 preferably fits into the cavity 202 of the outer hollow member 190 , with the second side 183 adjacent to the plate 204 of the hollow member 190 . The inner hollow member 192 fits over the planar spring 180 , so that the arm 184 and the semispherical surface 188 extend through the hole 200 in the inner hollow member 192 . Thereafter, the threads on the outer rim 196 engage with the threads on the inner surface 208 of the outer hollow member 190 , joining the hollow members 190 , 192 to form the casing 172 . The spring 180 is thusly captured inside the casing 172 , which prevents it from moving axially. When the arm 184 moves toward or away from the outer hollow member 190 , the planar spring 180 extends out of its plane. When the arm 184 returns to its original position, the planar spring 180 recoils back towards its plane. During this extension and recoiling, the plate 194 of the inner hollow member 192 and the plate 204 of the outer hollow member 190 act as barriers to limit the movement of the planar spring 180 . The arm 184 is encircled by the inner rim 198 , which acts as a bearing surface to prevent radial movement of the arm relative to the inferior hollow member 192 .
[0068] As seen in FIG. 20 , a coupling in the form of a two-part end housing 178 fits over each semispherical surface 188 , 212 . Each end housing 178 has a first wall 220 and a second wall 222 . The first wall 220 is shaped like a segment of a cylindrical body that is split lengthwise, and has an inner surface 224 and rounded outer surface 226 . At each lengthwise end of the first wall 220 , a rounded first hollow 228 is indented into the inner surface 224 . Indented into the inner surface 224 , between the hollows 228 , are two receiving holes 230 . The second wall 222 is also shaped like a segment of a cylindrical body and has an inner surface 234 and an outer surface 236 . Unlike the first wall 220 , the outer surface 236 is not rounded but is squared off so it is flat. The inner surface 234 has a rounded second hollow 238 indented into each lengthwise end. Each pair of rounded hollows 228 , 238 cooperates to define a socket sized to receive the corresponding ball 188 or 212 . Two pin holes 240 extend from the outer surface 236 through the wall 222 to the inner surface 234 , such that two pins 242 can fit through the pin holes 240 and into the receiving holes 230 in the first wall 220 . The pins 242 and receiving holes 230 releasably hold the walls 220 , 222 together around the semispherical surfaces 188 , 212 , and prevent shearing of the walls. In other embodiments of the invention, the pins 242 and receiving holes 230 could be replaced by posts and brackets, or a snap mechanism or other mechanisms capable of releasably joining the walls 220 , 222 .
[0069] The assembled stabilizer 170 fits into the yokes 16 of two anchoring members 19 , as is best shown in FIG. 17 (shown disassembled in FIG. 21 ). In the fully assembled state, the end housings 178 are preferably situated perpendicular to the fixation members 14 , so that the end housings 178 fit between support walls 144 of anchoring member 19 , and the rounded outer surface 226 is cradled on a curved floor 142 between walls 144 . Two set screws 18 are thereafter engaged in the threads 150 and tightened. The tightening of the set screws 18 creates pressure on the end housings 178 , holding the housings closed around the semispherical surfaces 188 , 212 . As described in the previous embodiment, each anchoring member 19 may comprise a unitary piece which includes both the fixation member 14 and the yoke 16 , or the fixation member 14 and the yoke 16 may be separate pieces. In such an embodiment where the fixation member 14 and yokes 16 are separate pieces, tightening of the set screws 18 may also press the end housings 178 against the heads 142 of the fixation members 14 , thereby restricting further rotation of the yokes 16 with respect to the fixation members 14 to secure the entire assembly.
[0070] Like the above embodiment, two stabilizers 170 can be secured end-to-end in accordance with this latter embodiment. When two stabilizers 170 are to be used together, the stabilizers are partially assembled as shown in FIG. 19 and described previously. The semispherical surface 212 or 188 from one stabilizer 170 is preferably placed in the empty hollow 228 of the first wall 220 of the second stabilizer 170 before the second wall 222 is joined to the first wall 220 . When the second wall 222 is joined to the first wall 220 , the semispherical surfaces 212 , 188 are captured in the socket sections 228 , 238 and the modules are joined. A stabilizer 170 can also be employed in combination with a rigid connector to provide dynamic stabilization across one level and posterior fusion across the adjacent level. Additional levels may be added as desired. Multiple stabilization/fusion levels can include two or more sequential rigid connectors, or rigid connecters sequentially interspersed with stabilizers.
[0071] Referring to FIG. 22 , a portion of an “overhung” dynamic stabilization system is shown. This system can be used when an offset between adjacent fixation members is desired and/or when a short pedicle-to-pedicle displacement must be accommodated. In this embodiment, a stabilizer 250 includes a housing 252 , an articulation component 254 and an arm 256 which extends from the joint. A tunnel 258 provides an opening for placement of the stabilizer 250 over an anchoring member (best shown in FIG. 26 ), and two set screws 259 are used to press a flexible stop 260 against the anchoring member, securing the stabilizer 250 in place.
[0072] FIG. 23 depicts an exploded view of the stabilizer 250 in more detail. As shown in that figure, the housing 252 has a chamber 262 which holds the articulation component 254 . A threaded cap 264 is screwed into the housing 252 closing off one end of the chamber 262 . A planar spring 266 with a threaded inner ring 268 is positioned within the cap 264 . Releasably screwed to the inner ring 268 is a socket 270 with a threaded end stud 272 . A cup 274 terminates the socket 270 at the end opposite the threaded end stud 272 . A semispherical surface 276 is connected to the arm 256 , and the semispherical surface 276 rotatably rests in the cup 274 . A tubular sleeve 278 surrounds the socket 270 , semispherical surface 276 and arm 256 . The sleeve 278 has a central bore 280 through which the arm 256 protrudes. The sleeve 278 also has two grooves 282 which run lengthwise down opposite outer sides of the sleeve. When the sleeve 278 , along with the enclosed socket 270 , semispherical surface 276 and arm 256 are in the chamber 262 , the sleeve is held in place by two pins 284 . The pins 284 are inserted through two pin holes 286 which perforate the outer wall of the housing 252 . The inserted pins 284 fit into the grooves 282 , and prevent the sleeve 278 and its enclosed contents from moving axially.
[0073] An unassembled stabilization system 248 is shown in FIG. 24 . The system 248 includes the overhung stabilizer 250 , an anchoring member 19 , an anchoring member 288 , an articulation component 24 , an end coupling 28 and an end cap 120 . As described in previous embodiments, the anchoring member 19 has a fixation member 14 , a yoke 16 and a set screw 18 . The anchoring member 288 comprises a fixation member 14 and an extension post 290 . Once again, the fixation members 14 may comprise pedicle screws, screws fixed to other parts of the vertebrae, pins, clips, clamps, adhesive members, or any other device capable of anchoring the stabilizer to the vertebrae. Additionally, each yoke 16 may be unitarily formed with a fixation member 14 as illustrated herein, or each yoke 16 may be a separate entity and be polyaxially securable to a fixation member 14 . The articulation component 24 has a tubular joining arm 292 extending from an end coupling 28 . The joining arm 292 is shaped to fit over the end of the arm 256 which protrudes from the articulation component 254 .
[0074] FIG. 25 illustrates the stabilization system 248 in a partially assembled state. The stabilizer 250 is joined to the articulation component 24 and end coupling 28 , with the joining arm 292 fitting over the end of the arm 256 which protrudes from the articulation component 254 through the use of a press fit or other attachment mechanism. The end cap 120 fits on the opposite end of the end coupling 28 , in the manner previously described. The fully assembled stabilization system 248 is shown in FIG. 26 . In this assembly, the end coupling 28 and end cap 120 fit in the yoke 16 of the anchoring member 19 , and are held in place by tightening the set screw 18 , in the same manner set forth previously. The assembled stabilizer 250 is placed over the anchoring member 288 , with the extension post 290 on the anchoring member 288 extending posteriorly through the tunnel 258 . The set screws 259 are engaged in the outer wall of the housing 252 adjacent to the extension post 290 . When the set screws 259 are tightened, they push against the flexible stop 260 , which in turn pushes against the post 290 , holding the stabilizer 250 in place on the extension post 290 . Finally, the joining arm 292 connects the articulation component 24 to the articulation component 254 , thus pivotably connecting the stabilizer 250 , secured to the anchoring member 288 , to the anchoring member 19 .
[0075] When the system 248 is fully assembled and anchored to two adjacent vertebrae, motion between the two vertebrae can cause the planar spring 266 to flex out of its plane. Referring back to FIG. 23 , when the two adjacent vertebrae move closer together and the distance between them shortens, the planar spring 266 returns to its plane. When the two adjacent vertebrae move apart and the distance between them lengthens, the planar spring 266 flexes in the opposite direction along the spiral path, toward the sleeve 278 . As the planar spring 266 flexes, the sleeve 278 which holds the articulation component 254 slides along the chamber 262 . The grooves 282 allow the sleeve 278 to slide back and forth past the pins 284 , but the pins 284 restrict axial movement of the sleeve 278 and serve as stops to prevent the sleeve 278 from moving completely out of the chamber 262 .
[0076] Referring to FIG. 27 , a multi-level dynamic stabilization system is shown which includes a stabilizer 12 as per FIGS. 1-8 , and an overhung stabilizer 250 as per FIGS. 22-26 . The stabilizer 12 is mounted on two anchoring members 19 and connected via the joining arm 292 to the overhung stabilizer 250 which is mounted an anchoring member 288 . The resulting dynamic stabilization system provides stabilization across two adjacent vertebral levels. The overhung stabilizer 250 allows one of the levels to have a relatively short pedicle-to-pedicle displacement. FIG. 28 illustrates the stabilizers 12 , 250 , two anchoring members 19 and one anchoring member 288 in an exploded view. Each anchoring members 19 includes a fixation member 14 , a yoke 16 and a set screw 18 , as set forth previously. The anchoring member 288 includes a fixation member 14 with an extension post 290 , as set forth previously.
[0077] Referring to FIG. 29 , the stabilizers 12 , 250 and the anchoring members 19 , 288 are shown in a further exploded view. The stabilizer 12 has two end couplings 28 , one end coupling 28 connecting with one end cap 120 thereby forming a coupling mountable in a yoke 16 . The second end coupling 28 of the stabilizer 12 preferably couples with the end coupling 28 that connects to the joining arm 292 , forming a coupling mountable in another yoke 16 . The joining arm 292 fits over the arm 256 of the stabilizer 250 , thus connecting the stabilizer 250 to the stabilizer 12 . The stabilizer 250 is mountable on the anchoring member 288 , in the manner set forth previously. When assembled, this two level system has two articulation components 24 , one articulation component 25 , and one articulation component 254 , providing pivotability between the stabilized vertebrae. Additionally, an overhung stabilizer 250 , a stabilizer 12 , and/or a stabilizer 170 such as that depicted in FIGS. 17-21 can be implanted in combination with a rigid connector 160 such as that depicted in FIGS. 14-16 .
[0078] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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An intervertebral stabilization device and method is disclosed. The device preferably includes a planar spring enclosed within a housing. The housing is joined to an articulation component at either end, and the articulation components have couplings connectable to anchoring components which are securable to adjacent vertebrae. The planar spring can flex and retract providing relative motion between the adjacent vertebrae. The articulation components are ball and socket joints which allow the entire assembly to flexibly follow the curvature of the spine. A fusion rod with articulation components and couplings at either end may be substituted for the spring device. The couplings enable interchangeability between a fusion rod assembly and spring assembly, so that dynamic stabilization can occur at one vertebral level and fusion at the adjacent vertebral level. An overhung spring assembly with a sideways displaced housing which allows for a shorter pedicle to pedicle displacement is also disclosed.
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[0001] The invention relates to a method for managing the braking of an aircraft comprising measurement of an inertial characteristic (acceleration, speed) directly close to the brakes.
BACKGROUND OF THE INVENTION
[0002] Aircraft fitted with undercarriages bearing braked wheels are known. The braking is managed by a braking computer which delivers braking commands to power distribution devices (servo-valves for the hydraulic brakes, controlled inverters or EMACs for the electromechanical brakes) which distribute braking power (regulated pressure or current) to the brakes. The braking commands are generally generated for each of the braked wheels taking account of a command slip rate to be applied to the wheel, which is calculated by comparing the longitudinal speed of the aircraft with the estimated peripheral speed of the wheel. If a difference appears, this is the sign that the wheel is starting to lock and it is appropriate to reduce the braking command until the wheel starts to rotate again sufficiently such that the peripheral speed is equal to the longitudinal speed reduced by the slip speed calculated using the command slip rate.
[0003] The longitudinal speed of the aircraft is generally provided by the inertial system of the aircraft.
PURPOSE OF THE INVENTION
[0004] The purpose of the invention is notably to improve the management of the braking of an aircraft, and to be able to propose new functionalities.
SUMMARY OF THE INVENTION
[0005] In order to achieve this objective, there is proposed a method for managing the braking of an aircraft fitted with undercarriages bearing braked wheels, the method comprising the step of generating braking commands by means of a braking computer for each of the braked wheels as a function of a difference between a peripheral speed of the wheel estimated using a tachometer generating a signal representative of the speed of rotation of the wheel, and a longitudinal speed representative of a longitudinal movement of the wheels in question. According to the invention, the longitudinal speed information used for the generation of the braking commands is generated with the help of a signal from a sensor separate from the tachometer disposed at the bottom of the undercarriage close to the braked wheels, making it possible to estimate the longitudinal speed at the level of the wheel which can transiently differ from the longitudinal speed of the aircraft.
[0006] Thus, rather than using longitudinal speed information generated by the inertial system of the aircraft, a signal is used which is measured as close as possible to the wheels by means of a dedicated sensor separate from the tachometer and which makes it possible to estimate the longitudinal speed at the level of the wheel accurately, which can differ transiently from the longitudinal speed of the aircraft because of the flexibility of the undercarriage and of the structure of the aircraft. Taking account of the refresh time of the braking commands (of the order of one tenth of a second), the method of the invention makes it possible to have the availability of relevant information of the instantaneous longitudinal speed of the wheel in question, thus preventing what is only an effect of the flexibility of the undercarriage and of the structure of the aircraft from being taken as a locking. The method of the invention thus makes it possible to improve the efficiency of the braking.
[0007] In practice, and according to a preferred implementation, the sensor comprises at least one accelerometer disposed close to the wheels, for example in an electronic housing fixed to the bottom of the undercarriage and adapted to measure the longitudinal acceleration undergone by the bottom of the undercarriage. The acceleration signal is then filtered and then processed in order to derive from it an item of longitudinal speed information which is representative of the true longitudinal speed of the braked wheels borne by that undercarriage.
[0008] The disposition of such a sensor close to the wheels allows new functionalities. For example, the signal from the sensor can be used for estimating the braking force developed by the brakes of the braked wheels borne by the undercarriage in question. Thereafter it is possible to set up a control of the rise in braking force in order to improve the comfort of the passengers, and to guarantee a maximum force level which makes it possible to size the structural parts subjected to the effects of the braking (undercarriages, undercarriage attachment members, structure of the aircraft etc.) more accurately.
[0009] Moreover, if the sensor comprises an accelerometer adapted to measure vertical accelerations, the corresponding signal can be used for estimating the vertical force undergone by the bottom part of the undercarriage, which is also called the suspended part as it is connected to the rest of the undercarriage by means of a shock absorber. Such estimation makes it possible to spot the cases of hard landing that can necessitate a maintenance operation on the undercarriage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will be better understood in the light of the following description of particular non-limitative implementations of the invention, given with reference to the appended figures among which:
[0011] FIG. 1 is a diagrammatic view of an aircraft fitted with an undercarriage bearing braked wheels and provided with an electronic housing equipped with accelerometers;
[0012] FIG. 2 is a diagrammatic view of the housing equipped with an accelerometer and mounted on the bus of the undercarriage;
[0013] FIG. 3 is a diagram showing the speed estimated by means of the signal from the accelerometer, and the speed of the centre of gravity of the aircraft as provided by the inertial system of the aircraft;
[0014] FIG. 4 is a view of a wheel whose axle is equipped with a housing containing an accelerometer.
DETAILED DESCRIPTION OF THE INVENTION
[0015] With reference to FIG. 1 , the invention applies to an aircraft equipped with undercarriages 1 which bear wheels 2 fitted with brakes. The aircraft comprises power distribution devices 3 (for example servo valves in the case of hydraulic brakes) which are controlled electrically in order to supply the brakes with power (for example a fluid having regulated pressure) in response to a braking command generated by a braking computer 4 disposed in the avionics bay of the aircraft. In order to generate the braking command of a given wheel, the computer receives the signal from a tachometer 5 representative of the speed of rotation of the wheel. Using this, the computer estimates the peripheral speed of the wheel by the formula v=R×w, where w is the speed of rotation estimated from the signal from the tachometer 5 , and R is the rolling radius of the wheel.
[0016] This speed must be compared with a longitudinal speed representative of a speed of longitudinal displacement of the wheel. In order to do this, and according to the invention, the undercarriage is equipped with an electronic housing 10 containing an accelerometer 11 adapted for measuring a longitudinal acceleration of the bottom of the undercarriage. In this case, the housing 10 is fixed on the beam 6 which bears the axles 7 receiving the wheels of the undercarriage. The housing can also be fixed on the sliding rod of the undercarriage at the end of which the beam is articulated. For undercarriages having only two wheels, the housing can be fixed on the sliding rod. It is essential that the housing should be placed close to the wheels, on a non-suspended part of the undercarriage.
[0017] The signal from the accelerometer 11 is processed by a processing unit 12 (filtering, conditioning etc.) in order to generate longitudinal speed V of the bottom of the undercarriage information, which is illustrated in the diagram shown in FIG. 3 . This figure shows the longitudinal speed of the bottom of the undercarriage information thus determined in dashed line, the speed of the aircraft as provided by the inertial system in solid line and the peripheral speed of the wheel in dotted and dashed line. In the figure there can be observed the differences of longitudinal speed which can be attributed to the flexibility of the undercarriage and of the structure of the aircraft, and which show that what could be detected as a start of locking is not in fact one. For example, in the detail A, a significant difference Ä between the peripheral speed of the wheel and the longitudinal speed provided by the inertial system can be seen, whereas the difference δ between the peripheral speed of the wheel and the locally measured longitudinal speed is not significant. Whereas the difference Δ would have given rise to the detection of a start of locking, the taking into account of the real difference δ makes it possible to avoid such false detections which result in releasing the braking force. This arrangement of the invention makes it possible to improve the control of the braking.
[0018] According to another aspect of the invention, the signal from the accelerometer 11 is used by the braking computer 4 for estimating a longitudinal force undergone by the bottom of the undercarriage. This force is representative, apart from the inertia of the masses borne by the bottom of the undercarriage, of the braking forces generated by the brakes of the wheels borne by the undercarriage. The estimation of the braking force by the means of the invention makes it possible to use strategies for limiting the rate of increase of braking force that are more efficient than the strategies currently used, such as limiting the increase of pressure which is generally carried out in a very conservative manner taking account of dispersion of the gains of the brakes. These strategies are used for avoiding any overload of the structure of the aircraft during the increase in braking force. It particularly relates to those aircraft having a long and relatively flexible fuselage, such as for example the Airbus A340-600. The direct estimation of the braking force developed by the wheels borne by an undercarriage makes it possible to implement a fine control, adapting to all possible dispersions of the gains of the brakes in question.
[0019] According to yet another aspect of the invention, the electronic housing 10 is equipped with a second accelerometer 13 adapted for measuring the vertical acceleration undergone by the bottom of the undercarriage. In the same way, the signal from the accelerometer 13 is filtered and processed in order to estimate a vertical force undergone by the bottom of the undercarriage, which is the suspended part of the latter. The vertical force information can be used for triggering warnings in the case of a hard landing or in the case of running off the runway generating large jolts capable of giving rise to a maintenance operation on the undercarriage and the associated wheels.
[0020] The invention lends itself to numerous variants. Provision can be made for measuring other accelerations, like a lateral acceleration making it possible to estimate the lateral forces undergone by the undercarriage during a turn, or for measuring angular accelerations of the bottom part of the undercarriage (by means of gyrometers for example, or of an accelerometer disposed at the end of a beam of a bogie undercarriages) making it possible to estimate instantaneous speed of rotation rates undergone by the bottom part of the undercarriage, or a torsion undergone by this same bottom part. The signals could also be dedicated by providing as many sensors as there are wheels. For example, as shown in FIG. 3 , for each wheel an accelerometer 14 is placed directly in a housing 15 attached to the end of the axle bearing the said wheel and which also encloses the tachometer. The longitudinal acceleration undergone by the wheel is then measured as close to the wheel as possible so that the longitudinal speed estimated from the said acceleration is very close to the true longitudinal speed of the wheel.
[0021] According to a particular aspect of the invention, advantage is taken of the presence of the sensor at the bottom of the undercarriage in order to generate maintenance warnings or for monitoring the state of health of the undercarriage.
[0022] In particular, if the sensor comprises an accelerometer capable of detecting hard landings (for example when the vertical force estimated using the second accelerometer exceeds a specified threshold) the information from the accelerometer is used for generating a warning which will be sent to the pilot and/or stored in a log. More generally, any type of monitoring of the state of health of the undercarriage can be implemented with the signals coming from the sensor of the invention.
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The invention relates to a method for managing the braking of an aircraft fitted with undercarriages ( 1 ) bearing braked wheels ( 2 ), the method comprising the step of generating braking commands by means of a braking computer ( 4 ) for each of the braked wheels as a function of longitudinal speed information representative of a longitudinal movement of the wheels in question, characterized in that there is placed at the bottom of the undercarriage, close to the braked wheels, a sensor adapted for generating a signal that can be used for generating the longitudinal speed information used for generating the braking commands.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an antibacterial calcium tertiary phosphate. More particularly, the invention relates to calcium tertiary phosphate made to carry silver and zinc and/or ions thereof, wherein calcium tertiary phosphate is safe, exhibits a high degree of whiteness and resist discoloration to the maximum extent.
Description of the Prior Art
It is known that metals such as silver and zinc as well as ions and salts of these metals exhibit a strong antibacterial property, and various processes have been proposed for utilizing these. However, when these metals are used as is in mixture with a substrate such as resin, fibers or paint, problems arise involving dispersibility with respect to the substrate, the eluting property of the metal ions, tinting and discoloration. For this reason, use in wide fields of application has not been possible.
Substances in which antibacterial metals, metal salts or metal ions are carried on highly safe ceramics have recently been proposed as substances which utilize the antibacterial property of the abovementioned metals. For example, antibacterial ceramics, in which the antibacterial metal ions are carried on zeolite, is disclosed in Japanese Patent Laid Open Publication Sho 60-181002 and antibacterial ceramics, in which the antibacterial metal ions are carried on hydroxyapatite, is disclosed in Japanese Patent Laid Open Publication Hei 2-180270. Since these substances exhibit reduced elution of the carried antibacterial metal ions into water and have improved dispersibility with respect to the substrate, they can be utilized comparatively safely and in many fields of application. However, depending upon the medium used, even these substances undergo elution of their metal ions into the medium, and therefore they cannot always be used with complete safety in all types of media.
Generally, silver is used as the antibacterial metal, because silver has strong antibacterial property. However, it is known that silver generally is sensitive to light and will break down and change color to gray or black when exposed to light. Accordingly, silver salts undergo discoloration when used as is. Antibacterial agents in which this metal salt is carried on ceramics or the like can lead to problems not only in terms of discoloration but also in terms of safety since the elution of silver from the silver salt and the release of silver salt from the ceramics cannot be reasonably prevented.
Though zeolite made to carry silver by means of ion exchange exhibits less discoloration in comparison to those cases where the silver salt is used as is, discoloration with the passage of time is unavoidable. In comparison with zeolite carrying silver, hydroxyapatite made to carry silver by ion exchange is much improved in terms of discoloration attributable to the silver, but complete suppression of discoloration has still not been realized.
Studies have been conducted with a view to improving upon the foregoing, and processes for carrying zinc along with silver on hydroxyapatite and further heat-firing has been considered. However, in cases where zinc is carried together with silver, the antibacterial hydroxyapatite tends to become light gray in color as the amount of silver carried is increased, and even though the color is close to white, the degree of whiteness is low. In addition, discoloration cannot be completely suppressed over an extended period of time. In cases where heat-firing is carried out, discoloration can be suppressed. Nevertheless, the antibacterial agent itself still becomes light brown in color and the degree of whiteness diminishes as the amount of silver carried increases. These problems arise when silver is used as the antibacterial metal, and though improvements have been made by carrying zinc and silver on hydroxyapatite and heat firing thereof, these still have not been resolved the problem totally.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide antibacterial calcium tertiary phosphate, which exhibits a high degree of whiteness, will not undergo discoloration even when stored for very long periods of time, and in which safe calcium tertiary phosphate is used as the carrier.
As mentioned above, an antibacterial agent obtained by having hydroxyapatite carry silver and zinc and/or ions thereof or subsequently being heat-fired is an easy-to-use antibacterial material which also exhibits excellent dispersibility in substrates, discoloration has been seen with the passage of time, and the antibacterial agent becomes light brown in color as a result. As a consequence, problems arise in terms of storage of the antibacterial agent and the color of manufactured articles produced with use of the agent, and therefore the fields of application are limited. Also, when the antibacterial agent, in which silver and zinc are carried on a carrier selected from calcium primary phosphate, calcium secondary phosphate and calcium pyro phosphate, and then heat-fired the problems in terms of discoloration, tinting, using and storing are overcome in comparision to using hydroxyapatite as the carrier.
Accordingly, the inventors have devoted research to silver-containing inorganic antibacterial agents which exhibit an ultra high degree of whiteness and will not undergo discoloration. As a result of this research, the inventors have been able to obtain an antibacterial agent which attains the foregoing objects. Specifically, by using calcium tertiary phosphate as the carrier and causing this carrier to carry silver and zinc, an antibacterial agent exhibiting an ultra high degree of whiteness and substantially suppressed discoloration has been obtained. By heat-firing calcium phosphate, which has been made to carry silver and zinc, at a temperature above 960° C., an antibacterial agent which exhibits a superior degree of whiteness higher than that of the heat-fired antibacterial hydroxyapatite, and which will not undergo discoloration, has been obtained.
More specifically, a prescribed amount of calcium tertiary phosphate is added to an aqueous solution, in which the prescribed amounts of silver and zinc salts are dissolved. The mixture is stirred. After sufficient stirring, precipitates are filtered out and the product is washed thoroughly with distilled water and then dried, whereby there is obtained an antibacterial calcium tertiary phosphate.
The degree of whiteness of the obtained antibacterial calcium tertiary phosphate ceramics naturally is influenced by the amount of silver carried, just as it is influenced by the adsorption retention ratio of the silver and zinc. That is, in order to obtain an antibacterial calcium tertiary phosphate exhibiting a superior high degree of whiteness and no change in color with the passage of time, the amount of silver adsorbed and retained should be no more than 10% by weight, and preferably no more than 5% by weight, with respect to the calcium tertiary phosphate. On the other hand, in consideration of antibacterial capability, the amount of silver retained preferably is no less than 0.0001%. When the amounts of silver carried on hydroxyapatite are over 0.1% in the antibacterial hydroxyapatite, even if zinc coexists, the color becomes bad, and discoloration occurs with the passage of time.
However, when calcium tertiary phosphate is used as the carrier, change in color is less. A change in color with the passage of time can be suppressed even further by heat-firing the product at a temperature above 961° C., which is the melting point of silver. The amount of zinc retained in coexistence with silver is required to be at least 5% by weight with respect to the amount of silver retained. The amount of zinc retained can be selected at will.
DETAILED DESCRIPTION OF THE INVENTION
An example of the present invention will now be described in detail.
EXAMPLE 1
1.0 kg of calcium tertiary phosphate, 0.002 of silver nitrate and 47 g of zinc nitrate were added to 10 l of distilled water and stirred. The product was filtered out, washed throughly with distilled water and dried and a portion of the resulting product was powdered to obtain an antibacterial calcium tertiary phosphate carrying silver, about 0.0001% and zinc, about 1% (1-1). The remainder of this product was heat-fired at 960° C., and powdered to obtain an antibacterial calcium tertiary phosphate carrying silver, about 0.0001% and zinc, about 1% (1-2).
EXAMPLE 2
1.0 kg of calcium tertiary phosphate, 2 g of silver nitrate and 0.24 g of zinc nitrate were added to 10 l of distilled water and stirred. The product was filtered out, washed throughly with distilled water, and dried, and a portion of the resulting product was powdered to obtain an antibacterial calcium tertiary phosphate carrying silver, about 0.1% and zinc, about 0.005% (2-1). The remainder of this product was heat-fired at 1,000° C. and powdered to obtain an antibacterial calcium tertiary phosphate carrying silver, about 0.1% and zinc, about 0.005% (2-2).
EXAMPLE 3
1.0 kg of calcium tertiary phosphate, 34 g of silver nitrate and 93 g of zinc nitrate were added to of distilled water and stirred. The product was filtered out, washed throughly with distilled water, and dried. A portion of the resulting product was powdered and an antibacterial calcium tertiary phosphate carrying silver, about 2% and zinc, about 2% was obtained (3-1). Also the remainder of this product was heat-fired at 1,200° C. and powdered. An antibacterial calcium tertiary phosphate carrying silver, about 2% and zinc, about 2% was obtained (3-2).
EXAMPLE 4
1.0 kg of calcium tertiary phosphate, 82 g of silver nitrate and 140 g of zinc nitrate were added to 10 l of distilled water and stirred. The product was filtered out, washed throughly with distilled water, dried. A portion of the resulting product was powdered and an antibacterial calcium tertiary phosphate carrying silver, about 5% and zinc, about 3% was obtained (4-1). Also the remainder was heat-fired at 1,200° C. and powdered. An antibacterial calcium tertiary phosphate carrying silver, about 5% and zinc, about 3% was obtained (4-2).
EXAMPLE 5
1.0 kg of calcium tertiary phosphate, 165 g of silver nitrate and 233 g of zinc nitrate were added to 10 l of distilled water and stirred. The product was filtered out, washed thoughly with distilled water and dried. A portion of the resulting product was powdered and an antibacterial calcium tertiary phosphate carrying silver, about 10% and zinc, about 5% was obtained (5-1). The remainder of this product was heat fired at 1,200° C. and powdered. An antibacterial calcium tertiary phosphate carrying silver, about 10% and zinc, about 5% was obtained (5-2).
EXAMPLE 6
Antibacterial Test
A solution containing 4.7×10 5 colon bacilli was added to a phosphate buffer solution, in which 1 weight % of each of the samples obtained in examples 1 to 5 was added, and the antibacterial property against the colon bacilli was measured for each sample. The result of measurement was that absolutely no bacteria was detected in 24 hours.
EXAMPLE 7
Degree of Whiteness Test
A spectrophotometer was used to measure the degree of whiteness degree of the antibacterial calcium tertiary phosphate powders produced in examples 1 to 5. Barium sulfate was used as the standard substance. As the control, hydroxyapatites carrying silver and zinc were prepared by the same way as shown in each example in which hydroxyapatite is used in place of calcium tertiary phosphate. ((Nonheat fired (control 1-1 to control 5-1), heat-fired (control 2-1 to control 2-5)) and the degree of whiteness was measured. Further, the degree of whiteness of these samples was measured after letting them stand in a bright room for 6 months. Similarly, nonheat fired and heat fired calcium tertiary phosphates carrying only silver (Nonheat fired (T1-1 to T5-1) and heat fired (T1-2 to T5-2)) and nonheat fired and heat fired hydroxyapatites carrying only silver (Nonheat fired (H1-1 to H5-1) and heat fired (H1-2 to H5-2)) were prepared, and the degree of whiteness was measured.
The results obtained are shown in Table 1.
The effects for the degree of whiteness and discoloration are clear when calcium tertiary phosphate is used as the carrier.
Comparison Example
Calcium secondary phosphate carrying silver 2%, calcium pyro phosphate carrying silver 2%, the heat fired bodies thereof which were heat fired at 1,200° C., calcium secondary phosphate carrying silver, 2% and zinc, 2%, calcium pyro phosphate carrying silver, 2% and zinc, 2%, and heat fired bodies thereof which were heat-fired at 1,200° C. were prepared and the whiteness degree was measured. The results are shown in Table 2.
TABLE 1__________________________________________________________________________measured value measured valueDegree of whiteness Degree of whiteness original after standing original after standingsample powder for 6 months sample powder for 6 months__________________________________________________________________________example 1-1 93.84 91.25 example 1-2 91.69 90.01control 1-1 93.32 89.98 control 1-2 88.13 86.22T 1-1 87.63 82.07 T 1-2 85.18 82.68H 1-1 87.84 81.73 H 1-2 83.23 80.21example 2-1 87.21 82.14 example 2-2 82.70 79.15control 2-1 87.49 77.40 control 2-2 79.25 75.10T 2-1 75.86 62.01 T 2-2 71.16 64.30H 2-1 74.64 60.03 H 2-2 69.45 63.21example 3-1 68.65 58.81 example 3-2 79.26 77.24control 3-1 62.55 41.05 control 3-2 73.61 70.33T 3-1 54.47 30.57 T 3-2 58.71 48.49H 3-1 53.25 28.91 H 3-2 55.55 50.84example 4-1 65.27 49.66 example 4-2 72.43 69.25control 4-1 61.20 33.20 control 4-2 67.11 61.87T 4-1 50.64 22.73 T 4-2 55.22 48.23H 4-1 50.44 <20 H 4-2 53.22 39.55example 5-1 61.82 40.31 example 5-2 64.90 60.55control 5-1 58.45 21.62 control 5-2 62.07 55.26T 5-1 47.47 <20 T 5-2 51.52 35.67H 5-1 46.17 <20 H 5-2 48.01 36.86__________________________________________________________________________
TABLE 2__________________________________________________________________________metal Degree of whitenessand not heat fired 1200° C. heat firedamount original after standing original after standingcarried carrier powder for 6 months powder for 6 months__________________________________________________________________________silver calcium secondary phosphate 57.49 25.32 58.16 45.922% calcium pyro phosphate 52.93 27.40 51.36 44.00silver calcium secondary phosphate 64.32 37.36 76.01 67.332%zinc calcium pyro phosphate 60.06 36.87 69.66 66.182%__________________________________________________________________________
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A calcium tertiary phosphate is used as a carrier, and the carrier is caused to carry silver and zinc. The result is an antibacterial ceramic exhibiting an ultra high degree of whiteness and suppressed discoloration. This material may be heat fired at a temperature above 960° C. to obtain a further improvement.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to an improved means of joining, or stacking, a plurality of structural, fluid, and/or electrical components. The invention can be used, in one example, to assemble components of a hydraulic control system.
[0002] Hydraulic control systems typically include a combination of fluid components, such as valves, actuators, pumps, and the like. The function of a particular hydraulic system is determined not only by the operation of the individual components, but also by their sequence or arrangement with respect to the flow path of fluid.
[0003] A control system is typically positioned between the source of the pressurized fluid (such as a pump), and the actuator that does the work (such as a linear cylinder or rotary motor). The control system dictates how the pressurized fluid will behave at the actuator, i.e. when the actuator will see pressurized fluid, at what pressure, how fast this pressure will ramp up or ramp down, at what flow rate, whether the flow will be constant or variable, in what direction the fluid will flow, etc.
[0004] Valve stacks have been a popular means of organizing the valves in a control system. Valve functions are separated and placed in their own body or envelope. These envelopes have opposing surfaces machined in a manner that allows fluid communication between them. Traditionally, these envelopes are stacked on a particular station of a manifold, with each station dedicated to a particular actuator. Thus, a four-station manifold would divide and control the fluid flow to four separate actuators.
[0005] The flow of fluid may be a round trip from the manifold, through the lowest valve element in the stack to the highest, and back again to the manifold, with each valve in the stack performing a particular function along the way. Separate channels would be provided in each valve element.
[0006] In practice, the last valve in a stack has often been a solenoid operated directional control valve. The other valves in the stack would be sandwiched between the directional control valve and the manifold.
[0007] The above-described stack configuration has significant problems. Long bolts or tie rods have been used to hold the components of a stack together, keeping them firmly abutted against their corresponding position on the manifold. For stacks containing many valve elements, this arrangement is problematic, as stretching of the bolt or tie-rod could cause the mating surfaces of adjacent valve envelopes to separate and leak. Also, the labor required in sizing and cutting thread stock for tie rods is considerable.
[0008] Stacking bolts have been used in the past to address the above problems. In a typical arrangement, a stacking bolt includes a head which has been hollowed and threaded, so that a fastening bolt, connected to a component above the first, could be screwed into the threaded portion of the stacking bolt. In principle, the system could include a series of bolts, each bolt being screwed into the head of an adjacent bolt. In effect, one replaces a long bolt or tie rod with a sequence of shorter bolts, each one being screwed to an adjacent bolt.
[0009] Stacking bolts have their own disadvantages, however, especially when a stack needs to be taken apart for servicing. The need for such servicing is common. For example, the electrical solenoid of a solenoid-operated directional control valve is prone to failure due to misapplication, and the solenoid often must be replaced. As this valve element is often the last in a stack, theoretically replacing the solenoid operated directional control valve should not be difficult. However, with the use of multiple stacking bolts in series, one is never certain which threaded connection in the series will loosen. When one unscrews the top bolt in the stack, it may not necessarily be the last set of stacking bolts associated with the directional control valve that loosens, but rather a bolt or bolts further down in the stack. This effect can cause leakage after the stack has been reassembled.
[0010] In recent years, larger manifolds that contain all the valve elements as cartridges have replaced stacks. Such a manifold comprises one monolithic piece of aluminum, steel, or cast iron. Each valve element is represented by a cartridge that is threaded into this manifold, and any cartridge may be removed for servicing, individually, without disturbing any other valve element. Although this type of monolithic manifold does solve the problems of stacked valve elements as described above, it can be quite expensive to design, and is not practical in short production runs where the engineering and machine set-up time can only be amortized over a few items. Thus it is not practical for prototype machines, or specialized or short production run machinery.
[0011] Furthermore, the design and machining of the above-described manifolds can be quite challenging. The design of complex manifolds often requires solid modeling software and experienced solid modeling engineers. The machining must be accomplished on very expensive numerically controlled four and five axis machining centers. Moreover, a machining error on the very last hole or cavity of the manifold can render the entire manifold scrap.
[0012] The flow paths within the above-described manifolds can be quite convoluted, with narrow bores having compound angles often necessary to connect the appropriate portions of the cartridge type valve elements. The pressure drops through these flow paths can be high, and often a large amount of potential work within the hydraulic fluid is wasted as heat.
[0013] Thus, in many circumstances, a valve stack arrangement is preferable to a monolithic manifold assembly.
[0014] A solution to some of the above-described problems with valve stack arrangements is provided by U.S. Pat. Nos. 4,848,405 and 4,934,411, the disclosures of which are incorporated by reference herein. Briefly, U.S. Pat. No. 4,848,405 describes an adapter plate within which a fastening bolt screws into the head of a stacking bolt below it. A resilient insert is located within the bore in the adapter plate, at the location where the bolts are screwed together. The insert causes the stacking bolt to be tightly held in a given position, such that when the fastening bolt is unscrewed, the torque exerted in unscrewing the fastening bolt does not cause rotation of the stacking bolt below. In effect, the insert stabilizes each joint, preventing unintended turning of bolts in the stack.
[0015] But the above-described solution has disadvantages. First, it is generally not compatible with mounting patterns made according to industry standards for directional control valves. The stacking arrangements of the prior art were conceived to be used with SAE, square, or other standard flange, tube, pipe, or hose mounting patterns, but not with industry standard directional control valve patterns where the distance between the bolt holes and the fluid channels are lessened. Generally, solenoid operated directional control valves used in valve stacks as described above are provided with industry standard fluid channel patterns (for example, D03, D05, etc.). These standards are delineated in ANSI/B93.7M-1986, entitled Hydraulic Fluid Power-Valves-Mounting interfaces. Each standard interface is defined by a group of fluid channel diameters and locations (i.e. pressure, tank, the work ports A and B, and pilot channels x and y), as well as mounting hole and locating pin locations and thread specifications.
[0016] The method of stacking described in the above-cited patents is not compatible with the above-mentioned industry standard valve-mounting interfaces. The enlarged bore portion of either the main body or the adapter portion that accommodates both the wrenching portion (i.e. the head) of the stacking bolt and the rotation resisting insert is of such a size that it interferes with either the locating pin, or comes unacceptably close to an O-ring cavity of a fluid port. There are literally millions of valves with these mounting interfaces in use today that are not compatible for use with the stacking systems of the above-cited patents.
[0017] Achieving such compatibility is not simply a matter of decreasing the outside diameter of the rotation-resisting insert. Doing so results in an insert that is too thin for the amount of deformation required to hold the stacking bolt firmly against rotation. Furthermore, the amount of deformation required in a thinner insert may result in permanent deformation of the insert and impair the ability to re-use the insert.
[0018] The solution proposed in U.S. Pat. No. 4,848,405 presents additional difficulties. The interior surface of the insert described above is keyed to the outside of the stacking bolt, and the polar orientation of the stacking bolts are unknown prior to installation. For this reason, the insert is provided as a separate piece from the adapter, with no reliable means for keeping it together with the adapter during shipping. Thus, an insert of this kind is frequently lost during transportation or handling.
[0019] Still another problem with the above solution is the difficulty of pressing the adapter plate onto the insert, while the insert is installed around the head of the stacking bolt. The insert is intentionally designed such that its outer diameter exceeds the inner diameter of the bore within which it is intended to sit, to insure a tight fit. But this tightness makes it very difficult to install the plate over the insert. An ideal solution to this problem is to use the fastening bolts, associated with the fluid component immediately above the adapter, as a jack. That is, one tightens the adapter plate by screwing the fastening bolt into the stacking bolt, and this tightening action forces the adapter plate into abutment with the fluid component below. However, this approach is generally not effective, because the fastening bolt is almost never long enough to serve adequately as a jack.
[0020] Still another problem with the use of the resilient insert described above is its tendency to become extruded when wedged between the head of the stacking bolt and the bore of the adapter plate. In particular, the material defining the insert sometimes becomes extruded upward, interfering with the seal between the adapter plate and the directional control valve (or other fluid component) located above the adapter plate. This effect ultimately leads to leakage of hydraulic fluid.
[0021] The present invention comprises an improvement to the stacking arrangement described above, and solves the above-mentioned problems. The invention may be used with standard hydraulic fluid power valve mounting interfaces. In addition, it may be used with SAE, square or other standard mounting patterns, and due to its advantages, it may be preferable for use with these patterns as well. More generally, the invention can be used in assembling many combinations of mechanical, hydraulic, and electrical components.
SUMMARY OF THE INVENTION
[0022] The present invention comprises an assembly of structural, fluid, and/or electrical components.
[0023] In one preferred embodiment, the invention comprises a stack of fluid components, wherein the stack includes a component having a stacking bolt, and a component having a fastening bolt, the fastening bolt being capable of being screwed into a hollowed head of the stacking bolt. The connection of the bolts is accomplished within the bore of an adapter plate. A resilient, annular insert is attached to the head of the stacking bolt, and therefore occupies the space between the head and the bore, thus preventing rotation of the stacking bolt when the fastening bolt is turned. At least a portion of the bore of the adapter plate is tapered, such that the diameter of the bore at or near the superior surface of the adapter plate is less than the diameter of the bore at or near the inferior surface. The insert has corners having a chamfer, the chamfer defining an incline having an angle which is is the same as, or approximately the same as, the angle made by the taper of the bore, in the vicinity of the superior surface, the angle being relative to the axis of the bore.
[0024] The above-described arrangement tends to prevent the insert from becoming lost during transportation or storage, because the insert can be wedged into the reduced diameter region of the bore produced by the taper, and tends to remain in this position due to friction. Also, as this reduced diameter region is located near the superior surface of the adapter plate, this construction tends to prevent upward extrusion of the material of the insert during assembly of the stack.
[0025] As noted above, due to the reduction in diameter effected by the taper, the hole in the superior surface of the adapter plate has a smaller diameter than the corresponding hole on the inferior surface. In particular, the hole on the superior surface is smaller than that provided in the industry standard patterns used in the prior art. Therefore, this arrangement prevents interference between fluid components, while still allowing the adapter plate to be used with fluid components having industry standard directional control valve mounting patterns.
[0026] The invention also includes a stacking kit, which can be used to form stacks of fluid components made according to the prior art. The kit includes the adapter plate as described above, one or more resilient inserts, and one or more stacking bolts.
[0027] The present invention therefore has the primary object of providing an assembly of structural, fluid, and/or electrical components, wherein components of the assembly can be easily removed for maintenance or replacement, without compromising the integrity of the other components of the assembly.
[0028] The invention has the further object of providing a stack of components, as described above.
[0029] The invention has the further object of providing an adapter plate for use in constructing a stack or assembly of components, the adapter plate having structure for assuring the integrity of seals in the assembly when the assembly is disassembled.
[0030] The invention has the further object of providing an improved stack or assembly having a resilient insert for locking the position of a stacking bolt, wherein the insert is unlikely to be lost, dislodged, or misplaced during transportation or storage.
[0031] The invention has the further object of providing a stacking kit for the stacking of conventional fluid components.
[0032] The invention has the further object of improving the efficiency and reliability of stacks or assemblies comprising structural, fluid, and/or electrical components.
[0033] The invention has the further object of enhancing the integrity of stacks of structural, fluid, and/or electrical components.
[0034] The invention has the further object of preventing leakage in stacks of fluid components, due to disassembly of such stacks for maintenance or for other purposes.
[0035] The invention has the further object of reducing or eliminating the labor required in sizing and cutting tie rods or thread stock.
[0036] The reader skilled in the art will recognize other objects and advantages of the present invention, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 provides a diagram representing a pattern of fluid ports and mounting holes, according to an industry standard, when used in connection with a stacking arrangement of the prior art.
[0038] FIG. 2 provides another diagram, similar to that of FIG. 1 , representing another pattern of fluid ports and mounting holes, according to another industry standard, as used with a stacking arrangement of the prior art.
[0039] FIG. 3 provides a side elevational view of a stack of fluid components, constructed according to the present invention.
[0040] FIG. 4A provides a more detailed, cross-sectional view of the adapter plate shown in FIG. 3 , the figure showing a stacking bolt and a rotation-resisting resilient insert affixed to the bolt.
[0041] FIG. 4B provides a view similar to that of FIG. 4A , but wherein the stacking bolt is not yet engaged with the resilient insert.
[0042] FIG. 4C provides a view similar to those of FIGS. 4A and 4B , but wherein the components are shown in an exploded configuration.
[0043] FIG. 5 provides a diagram analogous to that of FIG. 1 , but wherein the diameters of the mounting holes on the superior surface of an adapter plate have been reduced, in accordance with the present invention.
[0044] FIG. 6 provides a diagram analogous to that of FIG. 2 , but wherein the diameters of the mounting holes on the superior surface of an adapter plate have been reduced, in accordance with the present invention.
[0045] FIGS. 7A , 7 B, and 7 C show a top view, and cross-sectional views taken from the side and the end, of the adapter plate of the present invention.
[0046] FIG. 8 provides an exploded view of a stack of fluid components, according to the present invention.
[0047] FIGS. 9-12A provide diagrams showing the sequence of an assembly process of the stack of the present invention. FIG. 9 shows a manifold used with a directional control valve. FIG. 10 shows a valve attached to the manifold. FIG. 11 shows an adapter plate being inserted atop the valve. FIG. 12 shows a directional control valve installed over the adapter plate, but wherein the adapter plate has not yet been brought into abutment with the valve below. FIG. 12A illustrates the condition wherein the components have all been brought into full abutment.
[0048] FIG. 13 provides a cross-sectional view showing the relationship between the rotation resisting insert and the bore in the adapter plate into which the insert is to be pressed.
[0049] FIG. 13A provides a cross-sectional view, and a detailed cross-sectional view, of the adapter plate of the present invention, showing a tapered bore.
[0050] FIG. 13B provides a cross-sectional and detailed cross-sectional view similar to FIG. 13A , but showing a stepped bore.
[0051] FIG. 14 provides a cross-sectional view, and a detail, showing the adapter plate of the present invention, in which the outside diameter of the insert is essentially the same as the diameter of the bore in the adapter plate.
[0052] FIG. 15 provides a diagram, analogous to FIG. 6 , showing the present invention as used with an assembly including hydraulic and electrical components.
[0053] FIG. 16 provides a diagram showing the components of a stacking kit, made according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0054] The present invention provides means for mechanical fastening and locking of assemblies comprising structural, fluid, and/or electrical components. One such assembly comprises a stack of components. In the following description, the embodiment described in the most detail will be a stack of fluid components. However, it should be understood that the invention is not limited to use exclusively with stacks of fluid components or other components, and that the concept of the invention can be broadly applied to assemblies having components which are mechanical, electrical, and/or hydraulic in nature.
[0055] A stack of fluid components, according to a representative embodiment of the present invention, is shown in FIG. 3 , and in the corresponding exploded view shown in FIG. 8 . At the bottom of the stack is a manifold plate 21 , which is shown with ports 22 (labeled “T” for “tank”) and 23 (labeled “P” for “pressure”). In the example shown, ports 22 and 23 provide fluid connections to a fluid tank and a pump. A valve module 24 is positioned above the manifold and in contact therewith. An adapter plate 25 is positioned above the valve module. A directional control valve 26 is located above the adapter plate.
[0056] A directional control valve is typically used to control the direction of movement of various components, and may be used, for example, in controlling the operation of a bulldozer or backhoe, or in controlling the operation of a flight control surface of an aircraft, or for other purposes. In general, a directional control valve directs pressurized hydraulic fluid through a selected path so that the fluid causes a specific component to move in a certain direction. In the present application, the directional control valve is used as an example of a device which can comprise a major element of a stack of fluid components. However, the invention is not limited to use with directional control valves. Such valve could be replaced by another fluid component, or by a plurality of such components. In this specification, it is understood that the term “directional control valve” is used only as an example of a fluid component which could be present in a stack.
[0057] It should also be understood that FIG. 3 shows one of many possible stacks of fluid components. Thus, valve module 24 could be replaced by a larger number of such valves. The stack could have a plurality of adapter plates, positioned at various locations in the stack. The present invention is intended for use in any of a large number of configurations of stacks of fluid components.
[0058] The adapter plate 25 , which will be shown and described in more detail later, includes a plurality of bores which accommodate stacking bolts 27 . The stacking bolts extend from within the adapter plate, passing through the valve module 24 , and enter the manifold 21 . The stacking bolt has a head, the exterior portion of which is typically polygonal (such as hexagonal) in shape. The head of the stacking bolt has a hollowed area which is provided with threads, so as to accommodate a fastening bolt 28 which is screwed into the head of the stacking bolt. Typically, the fastening bolt is supplied with the component being assembled into the stack, such as the directional control valve. A resilient annular insert 29 is installed around the exterior of the head of the stacking bolt, and is therefore located between the head of the stacking bolt and the bore of the adapter plate. The insert is used to resist rotation of the stacking bolt, when the fastening bolt above it is turned. The insert is preferably made of a deformable material such as nylon or polyethylene. The adapter plate has a superior surface 46 and an inferior surface 47 , these surfaces being generally parallel to each other. The superior and inferior surfaces of the adapter plate are preferably made to be compatible with a standard hydraulic valve-mounting interface, so that the directional control valve, or other component, which has a standard configuration of ports, will fit with this interface.
[0059] FIGS. 4A-4C provide detailed, cross-sectional views of the adapter plate, stacking bolt, and resilient insert. FIG. 4A shows an assembly of the stacking bolt 27 , the adapter plate 25 , and the rotation resisting insert 29 . FIG. 4B shows the stacking bolt 27 separate from the assembly comprising the adapter plate 25 and the rotation resisting insert 29 . This is the preferred way that these components are delivered to an end user, with the insert pre-assembled into the adapter plate. FIG. 4C provides an exploded view of all three components.
[0060] An important feature of the present invention is that the bore of the adapter plate has a taper. The taper is continuous, and is plainly visible in FIG. 4C , which shows tapered wall 31 , but is also shown in FIGS. 4A and 4B . As shown most clearly in FIG. 4C , the taper may be provided only in the vicinity of the superior surface of the adapter plate, with the majority of the bore being of generally constant diameter. More details about the function and advantages of the tapered construction will be provided later.
[0061] The natural (i.e. undeformed) outside diameter of the insert 29 is slightly larger than the inside diameter of the bore of the adapter plate 25 . The insert 29 is pressed into the bore until it is stopped by the taper in the bore. The interference between the insert and the bore holds the insert, by friction, within the bore both axially and radially.
[0062] The outside diameter of the head of the stacking bolt is larger than the inside diameter of the insert. Therefore, when the stacking bolt is driven into the rotation-resisting insert, the insert material is deformed around the vertices of the polygonal head, and resists rotation of the stacking bolt. Engaging the bolts of the component above provides the force required to drive the polygonal head of the stacking bolt into the rotation resisting insert.
[0063] FIGS. 7A-7C show an adapter plate 41 with its associated rotation resisting inserts 42 assembled within as the end user receives it. The adapter plate includes a bolt hole configuration which corresponds to an appropriate industry standard. In particular, holes 43 are used for mounting the adapter plate to adjacent components, and holes 44 comprise fluid port holes for providing fluid connections between components.
[0064] FIGS. 7B and 7C show the taper at the ends of the bores, formed in the adapter plate, which bores receive the wrenching portion (i.e. the polygonal head) of a stacking bolt. The taper decreases the diameter of the hole at the superior surface of the adapter plate, so that the hole does not interfere with sealing O-rings on the adjacent component. The taper also serves a secondary purpose in that it limits axial displacement of the insert. That is, the taper prevents extrusion of the insert material above the plane defined by the superior surface of the adapter plate. Such extrusion may interfere with the seals at the component interface. This taper, and limiting of axial displacement, is also useful during assembly, as it lends itself to mechanical automation of the assembly process in the factory. The inserts may be pressed into their respective bores until they come in contact with the taper.
[0065] FIGS. 7A and 7C also show slots 45 formed near the inferior surface of the adapter plate. When the adapter plate has been jacked down to abut an opposing surface, these slots 45 define recesses into which a screwdriver, or the like, can be inserted to pry the adapter plate loose, when it is necessary to disassemble the stack. This arrangement essentially provides the leverage necessary to disengage the resilient insert from the heads of the stacking bolt heads.
[0066] The same effect could be accomplished by other means. For example, one could provide an additional threaded hole in the adapter plate, the hole being perpendicular to the superior and inferior surfaces of the plate, and one can put a small setscrew within this hole. The setscrew could then be used as a jack to pry the adapter plate away from the component beneath. Such screws are commercially available with brass or nylon tips so as not to mar the finish of the superior surface of the component(s) underneath.
[0067] FIGS. 9-12A show the sequence of steps in the assembly of the stack of the present invention. The process begins with manifold plate 51 , shown in FIG. 9 , the manifold being typical for use with stacks containing a directional control valve. FIG. 10 shows the same manifold 51 with a valve element 52 held in place by means of stacking bolts 53 . More than one valve element may be provided in series here. For example, two or three valve elements could be stacked on top of the appropriate station on the manifold and held in place by a set of stacking bolts.
[0068] FIG. 11 shows an assembly comprising an adapter plate 54 and rotation-resisting inserts 55 , placed atop the stacking bolts 53 . Absent any significant axial force, the inferior surface 56 of this adapter plate will rest above the superior surface 57 of the valve element due to the interference between the inside diameter of the inserts and the outside diameter of the stacking bolts.
[0069] FIG. 12 shows the addition of a directional control valve 58 and engagement of its associated bolts, including fastening bolts 59 . Full engagement of the bolts will result in the axial force necessary to deform the insert material around the head of the stacking bolt 53 , and to bring the adapter plate 54 and valve element 52 into direct contact. In FIG. 12A , the bolts have been fully engaged, and the components are in complete sealing abutment.
[0070] The cross-sectional view of FIG. 13 shows the relative diameters of the rotation resisting insert 61 and the bore 63 of the adapter plate 62 . The insert is to be pressed into bore 63 . The figure shows the desirability of a chamfer 64 at the leading edge of the insert, to facilitate introduction into the bore. The chamfer is provided on all corners of the insert, as shown, so that the insert can be installed in the bore of the adapter plate, without taking its orientation into account.
[0071] FIG. 13A shows a cross-sectional view similar to that of FIG. 13 , but showing the insert fully installed within the bore. FIG. 13A also contains a detail, illustrating more clearly the taper of the bore. Specifically, the detail shows tapered surface 70 of the bore of the adapter plate, the tapered surface generally mating with the chamfered portion of the insert 71 . That is, the tapered surface makes an angle, relative to the longitudinal axis of the bore, which is the same, or approximately the same, as the angle made by the chamfered surface relative to the longitudinal axis of the insert.
[0072] Note also that, in the preferred embodiment shown in FIGS. 13 and 13A , most of the bore has a constant diameter, and the taper is present only in a small portion of the bore, near the superior surface of the adapter plate. The invention is not limited to this structure; the taper could occupy a greater proportion of the bore than what is shown in the figures, if desired.
[0073] FIG. 13B shows an alternative embodiment, in which the bore of the adapter plate is stepped and not tapered. FIG. 13B shows step 82 which contacts insert 81 . This embodiment has some advantages over the prior art, but is far less advantageous than the tapered embodiment, as will be discussed later.
[0074] One advantage of the tapered construction of the bore of the adapter plate is that it effectively reduces the diameter of the hole associated with the bore, on the superior (upper) surface of the adapter plate. This reduction in diameter enables the present invention to be used with standard port configurations, but without interference between components. This feature is illustrated by FIGS. 1 , 2 , 5 , and 6 .
[0075] FIG. 1 shows a standard valve-mounting interface 1 , known in the industry by the designation “D03”, representing an ANSI standard. This figure does not represent one component, per se, but comprises a pattern of bolt and port holes which would be present at an interface in a stack of fluid components. Holes 2 , 3 , 4 , and 5 comprise bolt holes, i.e. holes used for mounting a fluid component to an adjacent component. These holes therefore correspond to the stacking bolts used in a fluid component stack, and to the bores of the adapter plate. Holes 7 , 8 , 9 , and 10 are fluid port holes, i.e. holes which allow fluids to flow from one component to the next. Hole 6 represents the position of a locating pin, which may be provided with one of the fluid components. For example, many fluid components with symmetrical or mirror-image fluid bore patterns (such as the pattern labeled D03) have a locating pin to prevent them from being installed incorrectly. A directional control valve, with a D03 pattern in particular, normally has a locating pin extending from its inferior surface. FIG. 1 , in the latter example, represents fluid ports at the interface between the inferior surface of the directional control valve, and the superior surface of the adapter plate.
[0076] FIG. 1 illustrates the fact that, in the prior art, the locating pin, represented by hole 6 , is tangent to, and may interfere with, one of the stacking bolts, represented by hole 4 .
[0077] FIG. 5 illustrates the corresponding pattern achieved as a result of using the present invention. The only difference between FIG. 1 and FIG. 5 is that the mounting holes, such as hole 90 , have a smaller diameter than the corresponding holes of FIG. 1 . This smaller diameter is a consequence of the tapered bore in the adapter plate. Because the mounting holes are smaller, there is space between hole 90 and hole 91 , pertaining to a locating pin, and the components mounted in these holes are unlikely to interfere with each other.
[0078] FIGS. 2 and 6 illustrate a similar principle for another standard bolt and port pattern, namely the ANSI standard known as “D05”. In this example, the standard bolt pattern includes mounting holes 12 , 13 , 14 , and 15 , corresponding to stacking bolts, and fluid port holes 16 , 17 , 18 , 19 , and 20 . FIG. 2 shows that bolt hole 15 may interfere with fluid port hole 19 , and bolt hole 14 may interfere with fluid port hole 20 .
[0079] But in FIG. 6 , which shows the result of the present invention, the bolt holes are smaller, due to the reduction in diameter achieved by the tapered adapter plate, and there is no longer interference between components mounted in these holes. Specifically, there is no interference between bolt hole 92 and fluid port hole 93 .
[0080] Thus, in FIGS. 1 and 2 , there is an unacceptably small clearance between the stacking bolt bore on the superior surface of the adapter plate, and structures associated with the adjacent component. In FIGS. 5 and 6 , the clearance is larger, and sufficiently large to avoid interference. In the case of FIG. 2 , the interference may occur between the stacking bolt and the O-ring cavity on the inferior surface of the directional control valve. There is a risk of overlap, leakage, and seal extrusion in light of manufacturing tolerances.
[0081] The above discussion addresses only the interface between the superior surface of the adapter plate and the inferior surface of the directional control valve, or other fluid component, above it. However, the bore of the adapter plate is not tapered towards its inferior surface. It turns out that any problem of interference at the inferior surface can be addressed conveniently in a different way. Specifically, any O-ring seals, with their respective cavities on the inferior surface of the adapter plate, can be made smaller than those present on the control valve adjacent to the superior surface, so that they do not interfere with the bore for the rotational insert. The superior surface of the adapter plate must be made to be compatible with the large quantity of directional control valves manufactured today. But the inferior surface, being a part of the adapter plate, need not have a pattern which is identical to the standard configuration.
[0082] Thus, for example, to avoid interference at the inferior surface of the adapter plate, one could simply make the diameter of an O-ring slightly smaller. Or one could move the position of the hole, in the adapter plate very slightly, to avoid interference while still maintaining the desired fluid communication. Such modifications could not conveniently be used at the superior surface because of the need to accommodate fluid components manufactured by others according to an industry standard.
[0083] The assembly of the fluid component stack of the present invention may be summarized as follows.
[0084] The stacking bolts are engaged and wrenched to fix the fluid component(s) beneath them. The adapter plate, containing the resilient inserts, is placed over the bolt heads. Due to the interference between the inside diameter of the inserts, and the normally polygonal heads of the stacking bolts, the adapter plate will be held offset from the component below, absent any axial force from above that would deform the insert around the head of the stacking bolt.
[0085] The component above is then placed onto the superior surface of the adapter plate, and its bolts are entered into threaded engagement with the stacking bolts below. This operation drives the adapter plate downward as the rotation resisting inserts are deformed about the heads of the stacking bolts. While the fastening bolts are being tightened into the heads of the stacking bolts, the taper of the bores in the adapter plate prevents upward displacement of the insert with respect to the adapter plate. The bolts of the final component are wrenched until the inferior surface of the adapter plate is in contact with the corresponding surface of the component beneath it, and an appropriate torque is applied to the bolts.
[0086] In the above-described assembly, the superior component may be disassembled without concern that the stacking bolt beneath it may become loosened. The adapter plate and inserts are engaged with their corresponding stacking bolts. These bolts are then provided with resistance to loosening, whereas the bolts above are not. This would be true if multiple stacking bolts/adapter plate combinations were used in series. In order for a wrench to engage the head of the stacking bolt, the adapter plate/inserts must be removed, thereby exposing the head of the bolt. (This may be accomplished by providing a pair of slots at the periphery of the inferior surface of the adapter plate into which a screwdriver or the like may be inserted to pry the adapter and insert assembly off of the stacking bolts). Any stacking bolts beneath these in series will still be engaged with their respective stacking bolt and inserts. Therefore, it will be the last set of stacking bolts in a series that will loosen.
[0087] It is strongly preferred that the bore of the adapter plate be tapered, rather than stepped. The rotation-resisting insert, in its preferred embodiment, is provided with a chamfer to allow it to more easily be introduced into the bore in the adapter plate. As the outside diameter of the insert is greater than the inside diameter of the bore, it is necessary to use a press to assemble the insert into the bore. The insert is pressed into the bore until it reaches the taper or step. In the case of the stepped bore, the insert comes in contact with the step only along a small portion at the periphery of its inside diameter (see FIG. 13B ). This results in almost point loading of the cantilevered section at the maximum distance away from the wall of the bore, and results in maximum bending stress at the root of the cantilevered section. Also, the force is distributed across a small area of the insert, and may result in yielding, or coining of the material, with the possibility of extrusion above the plane of the superior surface of the adapter plate, or extrusion into the ID. Extrusion above the plane of the superior surface can interfere with apposition of the superior surface of the adapter plate and the inferior surface of the directional control valve, and result in leakage. Extrusion into the ID can result in interference with the female threaded portion of the stacking bolt, and prevent engagement of the bolts of the directional control valve.
[0088] If a step were used, as illustrated in FIG. 13B and its detailed view, it would be desirable to make the step thick enough that it does not shear off during tightening of the bolts, but thin enough so as to minimize the distance between the top of the stacking bolt and the component above. With the tapered construction, as shown in FIG. 13A , the insert can be wedged almost all the way to the superior surface of the adapter plate.
[0089] In short, when the insert reaches the tapered section of the bore, the insert is in contact with the taper along the entire tapered section (see FIG. 13A ). This even distribution of the load results in a lower bending moment at the root of the cantilevered section. Also, the insert is in contact with the tapered section of the bore over a larger area, reducing the possibility of insert yielding or coining.
[0090] Finally, the incline of the taper provides increased radial force on the stacking bolt during assembly. As the stacking bolt is driven into the insert, any slight upward axial movement of the insert results in a slight decrease in the ID of the insert at its superior aspect, with a resultant increase in radial force at the interface of the stacking bolt and insert. This of course results in higher resistance to rotation of the stacking bolt within the insert/adapter plate assembly.
[0091] Also, as the thickness of the taper at the outside diameter of the stacking bolt is less than that of the stepped bore (for similarly stressed sections), the superior surface of the bolt is closer to the superior surface of the adapter plate in the tapered configuration. Thus, it is possible to use the standard length directional control valve bolts as jacking screws in this type of assembly.
[0092] The adapter plate and the inserts are shipped complete as one unit. This overcomes objection to shipping the inserts separately where they are at risk for loss due to misplacement. Also, assembly of the insert into the adapter plate can be done more economically at the factory, using an automated process.
[0093] The rotation-resisting insert is made with a bevel or chamfer that matches the taper of the bore. This allows the insert to be more easily started into the bore during assembly, and also allows the stacking bolt to be more closely positioned to the superior surface of the adapter plate prior to engagement of the bolt from the next component.
[0094] The insert may be cemented into the bore during assembly at the factory. Alternatively, the bore may be provided with longitudinal grooves into which the insert deforms as it is inserted into the bore. Either of these means serve to prevent the insert from rotating with respect to the bore. The inside diameter of the insert is made smaller than the outside diameter of the head of the stacking bolt. Therefore, during assembly, the head displaces the insert material and therefore the head is held in place and prevented from rotating.
[0095] The material for the insert is chosen to provide a sufficiently high modulus of elasticity to prevent the stacking bolt from rotating, while at the same time providing a material that allows a significant amount of deformation without permanent yield, so that the adapter plate and its associated inserts may be used over and over. Several materials fulfill these criteria, including certain types of nylon and polyethylene. Unfortunately, these materials also have a relatively low coefficient of friction against steel. However, it was determined experimentally that the outside diameter of the insert could be made larger than the bore so that the insert was radially compressed to a sufficient degree to provide a force between the insert and the bore adequate to overcome this low coefficient of friction.
[0096] For example, the recommended torque to tighten an oiled 10-24 socket head cap screw is 3.5 foot-pounds. This 10-24 thread is used on the D03 valve interface. The torque required to turn a stacking bolt with this thread, coupled only with a nylon insert dimensioned in the manner above, was as high as 12 foot pounds, far higher than the recommended torque for a socket head cap screw of this size. Therefore, the additional torque that will resist rotation provided by an insert held against the bore by friction alone is more than sufficient to guarantee that a stacking bolt held in this manner will not loosen before a bolt that is not so engaged.
[0097] The insert is designed so that when it is in place within the bore, the resulting inside diameter of the insert is about equal to the pitch diameter of the polygonal head of the stacking bolt that it will interface with. Therefore, the volume of material displaced by the head has an equal volume of space to flow to in the valleys between the points.
[0098] FIG. 14 shows an alternative embodiment of the invention, in which the outside diameter of the insert is essentially equal to the diameter of the bore of the adapter plate. In this embodiment, the insert is cemented or glued into the bore. FIG. 14 shows insert 73 , and adapter plate 72 having a tapered bore, with the insert being affixed within the bore by adhesive bond 74 .
[0099] FIG. 15 provides a diagram, analogous to FIG. 6 , showing the invention as used in a system comprising hydraulic and electrical components. FIG. 15 shows mounting holes 102 , 103 , 104 , and 105 , and fluid port holes 106 , 107 , 108 , and 109 . The figure also includes electrical receptacle 110 . As in FIG. 6 , the mounting holes have a diameter which is smaller than comparable mounting holes of the prior art (as exemplified by FIG. 2 ), so that such holes do not interfere with the components. FIG. 15 could be generalized further to include other combinations of structural, fluid, and/or electrical components.
[0100] FIG. 16 illustrates a stacking kit made according to the present invention. The kit comprises an adapter plate 113 , a plurality of resilient inserts 111 located within the bores of the adapter plate, and a plurality of stacking bolts 112 . The adapter plate may also be provided with slots, similar to those shown in FIGS. 7A and 7C , to facilitate removal of the adapter plate from the stack. The insert, the stacking bolt, and the adapter plate have the structures discussed with respect to the other figures. As illustrated in FIG. 16 , the thickness of the adapter plate is preferably slightly greater than the height of the head of the stacking bolt. In the example shown, the adapter plate has two bores. In practice, the number of bores can be varied, it being understood that, for each bore, there is included a resilient insert and a stacking bolt.
[0101] In some applications, the adapter plate may need to be very large. In such circumstances, it may be necessary to provide a larger number of stacking bolts than what is shown in the drawings. For example, in addition to the four stacking bolts located at or near the corners of the adapter plate, it may be appropriate to place additional stacking bolts midway along each side of the plate, or in other configurations. The present invention is intended to include these alternatives.
[0102] The invention can be modified in many other ways. As stated above, the stack of fluid components shown in the drawings is only one of a very large number of possible arrangements. The present invention is not limited to one particular stack. Also, more than one adapter plate can be used, according to the needs of a particular system. These and other modifications, which will be apparent to the reader skilled in the art, should be considered within the spirit and scope of the following claims.
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A stack or assembly of fluid, mechanical, and/or electrical components permits removal of some components for maintenance, without compromising the fluid integrity of the remainder of the assembly. A fastening bolt, attached to at least one fluid component, is screwed into a stacking bolt, attached to another fluid component, the bolts being screwed together inside the bore of an adapter plate. A resilient insert sits between the head of the stacking bolt and the bore. At least a portion of the bore has a continuous taper, such that the diameter of the bore decreases in the vicinity of the insert. The taper creates a reduced diameter hole on one surface of the adapter plate, thus preventing interference between fluid ports on an adjacent fluid component. The taper also prevents loss of the insert during transportation and storage, and prevents undesired extrusion of material of the insert when the components are fastened together.
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BACKGROUND OF THE INVENTION
[0001] The present invention provides for a method and apparatus to pre-condense components including water from a process gas stream. Liquid nitrogen is employed combined with cold process gas from a downstream processing unit to minimize the formation of ice. The method also provides for means to defrost excess ice accumulation while continuing at least partial pre-condensation.
[0002] Vent streams from many process plants often contain volatile organic compounds (VOCs) or similar compounds and frequently water. These VOCs must typically be removed from the vent stream to an acceptable degree by such abatement technologies as thermal destruction, adsorption or cryogenic condensation The cryogenic condensation approach for removing VOCs from vent stream is a well established technology that relies on reducing the temperature of the process gas stream and causing the VOCs to condense as a liquid. This condensed liquid may be collected and re-used or otherwise disposed of in an environmentally acceptable manner. Typical process gas outlet temperatures are in the range of −60° C. to −100° C.
[0003] There are limitations that reduce the efficiency and practicality of cryogenic systems. Among these limitations are the potential for freezing some VOCs or other components and the inefficiency of venting a very cold purified process gas which is typically air or nitrogen. The most notable component that can cause a freezing concern is water. A know method for reducing the amount of freezing, especially of water, that can occur in the main cryogenic condenser is to use a pre-condenser. This pre-condenser may employ a chilled water or brine refrigerant, but that adds complexity and cost to the overall system. Alternatively, the cold process gas has refrigeration value but there may be insufficient refrigeration value to accomplish the desired amount of pre-condensing. Liquid nitrogen may be injected and mixed with the cold process gas to increase its cooling potential however, that can cause unacceptable dilution of the vent gas and there is still a limit to the amount of additional cooling that may be achieved. Alternatively, liquid nitrogen may be used to indirectly cool the cold process gas prior to the pre-condenser, which avoids the unacceptable dilution but there remains a limit to the amount of additional cooling that can be achieved. For example, if the cold process gas is at a temperature of −90° C., then it can only be cooled further to about −180° C. while still remaining a cold gas coolant. Even as a cold gas coolant there can be problems with freezing in the pre-condenser at very low coolant temperature.
SUMMARY OF THE INVENTION
[0004] The present invention is able to minimize these limitations by employing a novel heat exchanger arrangement. The present invention enables pre-condensing with full recovery of the cooling potential of the cold process gas from a main condenser. Further the present invention provides the capability of adding essentially unlimited additional cryogenic cooling capability, limited only by surface area, necessary to achieve the desired amount of pre-condensing through the use of a co-current “tube in tube” approach.
[0005] The present invention also provides means to advantageously use the formation of ice within the pre-condenser to perform the pre-condensing Ice formation can also be minimized. The warm process gas can be used periodically to melt excessive ice formation while simultaneously continuing to provide at least partial pre-condensing.
[0006] The present invention will accomplish pre-condensing with a full recovery of the cooling potential of the cold process gas from a main condenser. The use of a co-current “tube in tube” pre-condensation unit will allow for adding essentially unlimited additional cryogenic cooling capability to the desired amount of pre-condensing. The present invention further uses the formation of ice within the pre-condenser advantageously to perform the pre-condensing. Further, the present invention provides a means to minimize excessive ice formation as well as allowing the warm process gas to periodically melt the excessive ice formation while simultaneously continuing to provide at least partial pre-condensing.
[0007] In a first embodiment of the present invention there is disclosed a method for pre-condensing components from a gas stream comprising the steps;
directing the gas stream into a pre-condensation unit wherein it is cooled to a pre-determined intermediate temperature; directing the gas stream at an intermediate temperature to a cryogenic condensation unit wherein the gas stream at an intermediate temperature is cooled to a final predetermined temperature; and directing the gas stream at a final predetermined temperature to the pre-condensation unit.
[0011] The process gas stream can be from an industrial process that contains components that need be removed the from the process gas stream. The components that are condensed out of the system include volatile organic compounds and water and are removed as condensate from both the pre-condensation unit and the cryogenic condensation unit.
[0012] Liquid nitrogen is employed to provide cooling to both the pre-condensation unit and the cryogenic condensation unit.
[0013] The pre-condensation unit is preferably a tube in tube heat exchanger, although other heat exchanger designs can be employed. The pre-condensation unit needs means for inputting a process gas stream to be cooled and an output means where the gas will be at a lower intermediate temperature when it leaves the pre-condensation unit. The lower intermediate temperature is considered versus the temperature of the process gas stream when it enters the pre-condensation unit and when it exits the primary cryogenic condensing unit.
[0000] The invention further comprises an apparatus for pre-condensing components from a gas stream comprising a pre-condensation unit; a cryogenic condensation unit; and at least one means for fluidly connecting the pre-condensation unit and the cryogenic condensation unit.
[0014] Preferably the pre-condensation unit is a tube in tube heat exchanger which has means for inputting a process gas a means for outputting a gas stream at intermediate temperature. The tube in tube heat exchanger will also have means for inputting liquid nitrogen and means for outputting exhaust nitrogen gas. The tube in tube heat exchanger will also have means for venting warm gas.
[0015] The tube in tube heat exchanger will also have means for inputting the gas stream at a predetermined final temperature. The tube in tube heat exchanger contains refrigeration tubes comprising outer and inner cooling tubes which are in thermal contact. Liquid nitrogen flows through the inner cooling tubes. Additionally a thermal shield may be disposed on at least a portion of the inner cooling tubes. The gas stream at final predetermined temperature flows through an annular space in the tube in tube heat exchanger.
[0016] Preferably the flows of the liquid nitrogen and the gas stream at a predetermined final temperature will be co-current and their flows being counter-current against the process gas stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic of the pre-condensing process of the present invention.
[0018] FIG. 2 is a schematic of the pre-condenser unit, tube in tube heat exchanger.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 is a schematic illustration of the process gas and liquid nitrogen flows associated with a pre-condenser and primary cryogenic condenser operating in accordance with the present invention. The incoming process gas stream 1 is shown entering the pre-condenser unit A where it is cooled to a predetermined intermediate temperature T 1 using a combination of economized cold process gas 3 from the primary cryogenic condenser unit B and additional liquid nitrogen 8 . The liquid condensed is separated and removed from the pre-condenser unit through line 10 , and the intermediate process gas 2 at temperature T 1 is fed to the primary cryogenic condenser unit B. The primary cryogenic condenser unit B introduces further cryogenic cooling using liquid nitrogen through line 5 to cool the process gas stream to a final predetermined temperature T 2 . T 2 is at a temperature less than T 1 which is less than the temperature of the process gas stream when it is inputted into the pre-condenser unit. T 2 is preferably about −40° C. to about −150° C. The liquid nitrogen 5 is preferably converted into a cold nitrogen gas stream prior to cooling the intermediate process gas from line 2 through indirect heat exchange. Further condensate is removed via line 4 from the primary cryogenic condenser, and the purified cold process gas at temperature T 2 is fed back through line 3 into the pre-condenser unit A as shown. After the cold process gas stream has provided cooling to the pre-condenser, it is vented as a warmed process gas 7 to the atmosphere.
[0020] There may be any number of additional process operations that occur upstream, downstream or between the two condensers shown in FIG. 1 . This may include additional upstream pre-condensers or heat exchangers, and further downstream process conditioning units such as adsorption beds. There may be intervening cryogenic operations including between the pre-condenser and primary condenser, or the primary condenser may include multiple heat exchangers. There may be multiple primary condensers, and multiple pre-condensers configured for example to alternate in operation to enable the defrosting operations.
[0021] Additional active defrosting mechanisms, including electric heaters or warm gas flows may be implemented in both the pre-condenser and primary condenser.
[0022] FIG. 2 is a more detailed representation of the pre-condenser of the present invention illustrating the features described with respect to FIG. 1 . The overall arrangement is a traditional shell and tube heat exchanger C where the process gas inlet 12 is cooled on the shell side by outer refrigeration tubes C 1 . The outer refrigeration tubes C 1 will generally operate below the freezing point of some of the components, which in the present process is expected to be water which freezes at about 0° C. Therefore, it is expected ice will build on the outer surface of the refrigeration tubes until a thermal equilibrium is achieved. When thermal equilibrium is reached, the outer surface of the refrigeration tubes will mostly be coated with ice and be at temperatures close to 0° C., and further condensation of water will continue based on the temperature difference between the process gas and the ice surface temperature. It is expected that the predetermined intermediate process gas temperature will be selected to be somewhat above the expected ice surface temperature. For the situation of water, an expected value for T 1 is about −10° C. to about 10° C. with a temperature of about 1° C. to about 5° C. preferred.
[0023] The process gas stream 1 from FIG. 1 enters the pre-condensing unit C through inlet 12 and as shown in FIG. 2 follows an “S” shaped path through the heat exchanger to exit at temperature T 1 through outlet 13 . The condensate indicated as line 10 in FIG. 1 will exit the heat exchanger through condensate drain 17 .
[0024] The refrigeration tubes employ a “tube in tube” arrangement which has co-current flow of liquid nitrogen in the inner cooling tube C 2 and cold process gas in the annular space. The co-current arrangement of the two coolants, counter-current to the shell side process gas, helps to ensure the optimum thermal utilization of the coolants by venting these at as warm a temperature as possible.
[0025] There are two advantages to the “tube in tube” arrangement. First, the amount of additional cryogenic cooling which may be provided is limited only by the surface area of the refrigeration tubes, allowing the ice layer that is expected to form on the outer surface. Second, the annular space containing the cold process gas separates the extreme low temperature of liquid nitrogen from being directly exposed to the process gas on the shell side. This serves to reduce the rate and thickness of the ice growth on the outer surface. In general, the ice will tend to accumulate more at the cold end of the heat exchanger C. While optional, the thickness of the ice layer in the cold region of the heat exchanger can be minimized by introducing a suitable thermal shield of insulation C 3 on the inner cooling tube in the cold region of the heat exchanger. This optional thermal shield has the added advantage of allowing the cold process gas to provide refrigeration before being introduced to the additional refrigeration effect of the liquid nitrogen. This reduces both the outer ice layer growth in the cold region, as well as potential freezing of remaining uncondensed VOCs contained in the cold process gas.
[0026] The pre-determined temperature T 1 of the intermediate process gas exiting the pre-condenser is maintained by adjusting the flow rate of liquid nitrogen 14 through to nitrogen exhaust 15 using valve V 1 . This assumes the normal circumstance where the amount of cooling required is greater than is available from the cold process gas alone entering the heat exchanger through line 16 .
[0027] It is expected that during the usual operation the expected growth of ice on the outer cooling tubes will achieve an equilibrium that can be accommodated by the design of the heat exchanger. The rate of condensation becomes equal to the rate of heat transfer through an ice layer having an outer surface at a temperature of about 0° C. However, during prolonged operation or certain operating conditions the ice layer may grow beyond what can be accommodated. In that case, a variety of passive defrost techniques are envisioned by the present invention. Once an ice layer has formed on the outer tubes it is possible to turn off either or both the liquid nitrogen 14 and cold process gas 16 without having a significant impact on the pre-condensing of the inlet process gas 12 . However, with either or both of these cooling sources turned off, the rate of ice formation will generally reverse and begin to melt. The mechanism for turning off or reducing the liquid nitrogen flow 14 is by using valve V 1 , while the mechanism for turning off the cold process gas coolant 16 is by closing outlet valve V 3 and opening bypass valve V 2 . By turning off the cold process gas 16 , thermal separation will continue to be proved between the inner and outer coolant tubes. It is anticipated that turning off or reducing the flow of liquid nitrogen 14 will generally be adequate to cause passive defrost. It is further anticipated that the normal operation of the overall cryogenic condensation system will not generally be adversely impacted by a modest rise of temperature T 1 during the period of passive defrost.
[0028] The heat exchanger arrangement may be of a variety of designs, including alternatives to the traditional shell and tube arrangement. The tube in tube arrangement may be effected by a variety of arrangements that could include non-circular geometries or multiple inner tubes.
[0029] A variety of process gas compositions either with or without water are possible. Freezing in the pre-condenser may not always occur and may occur at a variety of characteristic temperatures.
[0030] The operating pressures may be other than atmospheric and the process gas vent 18 may or may not be to the atmosphere. For example, the overall system may be part of an internal recycle system.
[0031] The flows of the two coolants, cold process gas and liquid nitrogen may be co-current ( 12 to 13 ) as shown in FIG. 2 or counter current. The coolant flows may be either counter-current with the shell side process gas ( 14 to 15 ) as shown in FIG. 2 or co-current.
[0032] While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of the invention will be obvious to those skilled in the art. The appended claims in this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the invention.
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A method and apparatus for removing components from a gas stream by feeding the gas stream into a pre-condensation unit to produce a gas stream at a lower intermediate temperature and feeding this intermediate temperature gas stream into a cryogenic condensation unit where a lower predetermined final temperature is achieved. This final temperature gas stream is directed back to the pre-condensation unit to assist in cooling the gas stream entering this unit.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This utility patent application is based on U.S. provisional patent application No. 60/216,752, filed Jul. 7, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is a latch for actuation with both an electric motor and manually.
[0004] 2. Description of the Related Art
[0005] Latch assemblies are relied on in many applications for securing items, such as panels, together. For example, containers, cabinets, closets, compartments and the like may be secured with a latch. An important use for latches is in the automotive field, where there is a desire and need to access automotive compartments, such as, for example, the trunk or passenger compartments of vehicles, as well as interior compartments such as a glove box.
[0006] Various latches for panel closures have been employed where one of the panels such as a swinging door or the like is to be fastened or secured to a stationary panel or compartment body. The prior art devices generally utilize a locking member which is spring-loaded externally by one or more separately provided torsion springs. For example, some prior art devices rely upon a lock which comprises rigid metal parts and requires additional biasing members for operation of the assembly. It has been increasingly more important and desirable to provide remote features for operation of latch mechanisms which permits a user to operate the latch from a location remote of that at which the latch is installed. For example, automobile latches often rely on the use of remote devices to open and close door locks, for example, using infrared, radio, or other wireless transmission modes. In addition, vehicle trunks often are provided so that they can be unlocked by remote means to permit the raising or opening of a panel.
[0007] In furnishing remote latching mechanisms, it must be taken into account that in some instances remote means may have failures, such as, for example, due to a loss of power supply (especially where electronic circuitry is employed). It is therefore also desirable to provide additional or secondary latching capabilities in order that the latch can be locked or opened manually, should the remote mechanism fail. In some instances, capped openings are provided in the vicinity of the latch which can permit a user to access the latch to open it should the remote mechanism not be operable. However, where security is concerned, it is not practical to provide an easy means for gaining an ability to open a latch. In these instances, complex mechanisms have been employed.
[0008] It is desirable to provide a latch which can be utilized both, by a remote locking mechanism and a key operated mechanism, and furthermore, where both the remote and the key operation can be used alternately as desired by the user. That is, it is desirable to have a latch with a locking capability where either a remote locking mechanism or a manual (key type) mechanism can be used to lock or unlock the latch, regardless of which one had previously been used.
[0009] The present invention provides a novel ratcheting pawl latch with the ability to lock and unlock the latch with remote and key operated mechanisms.
SUMMARY OF THE INVENTION
[0010] The present invention is a latch that may be operated either by an electric motor, possibly remotely, or manually. The latch includes a lockplug housing, a motor housing, a lockplug, a lockplug driver, a locking disk, a pawl, and a pair of roller switches.
[0011] The pawl includes a pair of arms and a locking disk engagement tooth. The pawl pivots between a latched and unlatched position, and is spring-biased towards its unlatched position. The pawl is dimensioned and configured to secure a wire keeper between its two arms.
[0012] The locking disk is pivotally secured between the lockplug housing and the motor housing. The locking disk defines a bearing surface around its circumference, which further defines a window dimensioned and configured to permit passage of the pawl, and a pair of cutouts. The locking disk pivots between a locked position and an open position, defining an unlocked range of positions therebetween. The locking disk is spring-biased away from the open position, but is not spring-biased in either the locked position or the unlocked range of positions. In the locked and unlocked positions, the edge of the locking disk abuts the locking disk engagement tooth of the pawl, thereby securing the pawl in its latched position. When the locking disk is rotated to the unlocked position, the window is aligned with the pawl, allowing the pawl to rotate to its unlatched position. The locking disk will then abut the pawl's locking disk engagement tooth, preventing the locking disk from rotating out of the locked position.
[0013] One side of the locking disk engages a gearbox, which in turn engages a motor. The motor is preferably a 12-volt DC motor, but is not limited to this type. The DC motor may be controlled by any of several means, including a programmable logic controller, a dashboard mounted switch, and/or a remote switch. The opposite side of the locking disk engages the lockplug driver.
[0014] The lockplug and lockplug driver turn as a single unit within the lockplug housing. The lockplug is spring-biased towards a central position. The lockplug driver engages the locking disk by means of a pin projecting from the locking disk into a slot in the lockplug driver. The slot extends for 90° around the lockplug driver. Therefore, the lockplug must be rotated 45° in either direction before engaging the locking disk. Likewise, when the motor rotates the locking disk, the locking disk is free to rotate 45° before engaging the lockplug driver. This is necessary because a force applied to rotate the lockplug will rotate the DC motor as well, but a force applied through the DC motor will have no way to rotate the lockplug.
[0015] The latch includes a pair of roller switches between the motor housing and lockplug housing. Each roller switch includes a cantilever with a roller end abutting the bearing surface of the locking disk. Depressing the cantilever closes an electrical circuit. When the roller abuts a cutout in the locking disk, the cantilever is extended, opening the circuit. Likewise, when the roller abuts the other portions of the disk's bearing surface, the cantilever is depressed. One cutout corresponds to the latch's locked position, and the other corresponds to the latch's open position. Therefore, the first of the two roller switches will be open when the latch is locked, and the second of the two roller switches will be open when the latch is open. The combined state of the two latches therefore indicates whether the latch is locked, unlocked, or open. This signal can be directed to a programmable logic controller (PLC), which, given the current state of the latch, and the desired state of the latch from a remote controller, will turn the motor the proper amount to bring the latch into the desired state. For example, if the latch is unlocked (both roller switches closed) and the user switches the latch to open, the PLC will rotate the motor until the second roller switch engages the corresponding cutout in the locking disk and opens. The PLC will then receive a signal that the latch is open, and stop rotating the motor.
[0016] It is a principal object of the present invention to provide a novel latch assembly which is selectively engagable with a keeper member, and includes a spring locking member which is spring-loaded with its own spring force for engaging and releasing a pawl from a keeper member when a handle is actuated.
[0017] It is another object of the present invention to provide a locking member which is comprised of spring steel or plastic.
[0018] It is another object of the present invention to provide a latch assembly with a locking component which can be operated with a key or other operator, such as radio, infrared, electronic or other means, which selectively engages the locking member against movement.
[0019] It is another object of the present invention to provide a latch assembly with a locking mechanism which can be operated with a key or other operator, such as, a solenoid controller, where the key and solenoid control the same locking element but provide independent ways to lock and unlock the latch.
[0020] These and other objects of the invention will become apparent through the following description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention.
[0022] [0022]FIG. 2 is a rear view of an electrically operated ratcheting pawl latch according to the present invention.
[0023] [0023]FIG. 3 is a side view of an electrically operated ratcheting pawl latch according to the present invention.
[0024] [0024]FIG. 4 is an exploded perspective view of an electrically operated ratcheting pawl latch according to the present invention.
[0025] [0025]FIG. 5 is an exploded side view of an electrically operated ratcheting pawl latch according to the present invention.
[0026] [0026]FIG. 6 is a perspective view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.
[0027] [0027]FIG. 7 is a bottom view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.
[0028] [0028]FIG. 8 is a rear view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.
[0029] [0029]FIG. 9 is a perspective view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.
[0030] [0030]FIG. 10 is a side view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.
[0031] [0031]FIG. 11 is a rear view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.
[0032] [0032]FIG. 12 is a perspective view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.
[0033] [0033]FIG. 13 is a front view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.
[0034] [0034]FIG. 14 is a side view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.
[0035] [0035]FIG. 15 is a perspective view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.
[0036] [0036]FIG. 16 is a front view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.
[0037] [0037]FIG. 17 is a rear view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.
[0038] [0038]FIG. 18 is a perspective view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.
[0039] [0039]FIG. 19 is a side view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.
[0040] [0040]FIG. 20 is a rear view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.
[0041] [0041]FIG. 21 is a perspective view of a pawl for an electrically operated ratcheting pawl latch according to the present invention.
[0042] [0042]FIG. 22 is a perspective view of a pawl spring for an electrically operated ratcheting pawl latch according to the present invention.
[0043] [0043]FIG. 23 is a perspective view of a roller switch for an electrically operated ratcheting pawl latch according to the present invention.
[0044] [0044]FIG. 24 is a perspective view of a sungear for an electrically operated ratcheting paw latch according to the present invention.
[0045] [0045]FIG. 25 is a perspective view of a torsion spring for an electrically operated ratcheting pawl latch according to the present invention.
[0046] [0046]FIG. 26 is a perspective view of a gearbox for an electrically operated ratcheting paw latch according to the present invention.
[0047] [0047]FIG. 27 is a perspective view of a motor for an electrically operated ratcheting pawl latch according to the present invention.
[0048] [0048]FIG. 28 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch locked.
[0049] [0049]FIG. 29 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch unlocked.
[0050] [0050]FIG. 30 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch open.
[0051] Like reference numbers denote like elements throughout the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] The invention is an electrically operated ratcheting pawl latch. Referring to FIGS. 1 - 5 , the latch 10 includes a lockplug housing 50 , a motor housing 100 , a lockplug 150 , a lockplug driver 200 , a locking disk 250 , a pawl 300 , a pair of roller switches 350 , at least one gearbox 400 , and a motor 450 .
[0053] Referring to FIGS. 6 - 8 , the lockplug housing 50 is illustrated. The lockplug housing 50 includes a front 52 , a bottom 54 , a pair of sides 56 , 57 , and a top 58 . The front 52 defines a channel 60 dimensioned and configured to receive a lockplug driver 200 (described below) and a cylinder 62 dimensioned and configured to receive a lockplug 150 . The cylinder 62 defines a recess 64 for receiving a plurality of locking wafers of the lockplug 150 (described below). A pawl nest 66 protrudes from the bottom 54 , and a window 68 , dimensioned and configured to receive a pawl 300 (described below), is defined in that portion of the bottom 54 within the pawl nest 66 . The pawl nest 66 preferably includes a pair of coaxial apertures 67 . Referring specifically to FIG. 8, illustrating the rear or inside portion of the lockplug housing 50 , a locking disk wall 70 is illustrated surrounding the channel 60 . A lockplug torsion spring driving tooth 72 is defined within the channel 60 , adjacent to the cylinder 62 . A locking disk torsion spring tooth 74 is defined opposite the tooth 72 , adjacent to the cylinder 62 but outside the channel 60 . Adjacent to one side 56 , a plurality of risers 76 is positioned for retaining a pair of roller switches 350 (described below). The side 56 defines a pair of windows 78 for permitting access to the contacts on the roller switches 350 , best seen in FIG. 7. The lockplug housing 50 preferably includes a plurality of mounting holes 80 for securing the lockplug housing 50 to the motor housing 100 .
[0054] The motor housing 100 is best illustrated in FIGS. 9 - 11 . The motor housing 100 includes a panel 102 , from which a rearward portion 104 extends. The rearward portion 104 defines a motor-containing portion 106 and a gearbox-containing portion 108 . The motor-containing portion 106 preferably includes a window 110 for passage of the electrical contacts to the motor 450 . The opposite side of the panel 102 includes a perimeter wall 112 , dimensioned and configured to contain the locking disk 250 . The motor housing 100 includes risers 114 , dimensioned and configured to secure the roller switches 350 in place. A guide slot 118 is defined around a 90° section of the perimeter wall 112 . The panel 102 preferably includes mounting holes 116 for securing the motor housing 100 to the lockplug housing 50 .
[0055] A lockplug 150 is illustrated in FIGS. 12 - 14 . The lockplug 150 includes a key slot 152 within its front end 154 . The rear of lockplug 150 may include a peg 156 . A plurality of wafers 158 extends from slots 160 within the side wall 162 of lockplug 150 . When a key is inserted and engages tumblers 164 , the wafers 158 are retracted. Likewise, removing the key extends the wafers 158 . A retention wafer 166 is spring-biased outward from a slot 168 within the side wall 162 .
[0056] A lockplug driver 200 is illustrated in FIGS. 15 - 17 . The lockplug driver 200 includes a cylinder 202 , dimensioned and configured to receive the lockplug 150 . The cylinder 202 includes a slot 204 , dimensioned and configured to receive the retention wafer 166 . The rear portion 206 includes an aperture 208 , dimensioned and configured to receive the lockplug's peg 156 . Opposite the cylinder 202 , the rear portion 206 also defines a central aperture 212 , and a channel 214 , extending for 90° around the aperture 212 . The aperture 212 is dimensioned and configured to engage a center post of the locking disk 250 (described below). The channel 214 is dimensioned and configured to engage a driver post on the locking disk 250 . A spring retaining tab 210 protrudes outward to one side of the cylinder 202 .
[0057] The lockplug 150 is inserted into the lockplug driver 200 so that the retention wafer 166 engages the slot 204 , and the peg 156 engages the aperture 208 . In use, the lockplug 150 and lockplug driver 200 will rotate as a single unit, and will be biased towards the position wherein the wafers 158 will engage the recess 64 . The means for biasing the lockplug 150 and lockplug driver 200 is preferably a spring such as the spring 550 illustrated in FIG. 25.
[0058] The locking disk 250 is best illustrated in FIGS. 18 - 20 . The locking disk 250 includes a central post 252 and a driver post 254 on its front face 256 . The front face 256 also defines a cavity 258 , dimensioned and configured to receive a spring and the locking disk torsion spring tooth 74 of the lockplug housing 50 . A spring retention feature 272 is also defined within the cavity 258 . The rear face 260 includes an aperture 262 , dimensioned and configured to receive a sungear 500 (illustrated without teeth in FIG. 24), and a deadstop lug 264 , dimensioned and configured to engage the slot 118 within the motor housing 100 . The locking disk's circumference 266 defines a bearing surface having a pair of cutouts 268 , and a window 270 , dimensioned and configured to receive the pawl 300 .
[0059] The locking disk 250 is positioned immediately behind the lockplug driver 200 , with the central post 252 engaging the aperture 212 , and the driver post 254 engaging the slot 214 . In use, the locking disk 250 will pivot between an open position and a locked position, with an unlocked range of positions defined therebetween, and will be biased away from the open position. Preferred and suggested means for biasing the locking disk 250 away from the open position is the spring 550 .
[0060] The pawl 300 is illustrated in FIG. 21. The pawl 300 includes a locking disk engaging tooth 302 , a first arm 304 , and a second arm 306 . The arms 304 , 306 are substantially parallel and opposite the locking disk engaging tooth 302 . A slot 310 is defined between arms 304 , 306 , and is dimensioned and configured to receive a wire keeper (not shown, and well-known). The pawl 300 also includes means for pivotally securing it within the latch 10 , with preferred and suggested means being pegs 308 , dimensioned and configured to mate within the apertures 67 within the pawl nest 66 . With the pawl 300 secured within the apertures 67 , the pawl 300 will pivot between a latched position and an unlatched position, and will be biased towards its unlatched position. Preferred and suggested means for biasing the pawl 300 towards its unlatched position are the spring 552 , illustrated in FIG. 22. The locking disk 250 will abut locking disk engaging tooth 302 of the pawl 300 when the locking disk 250 is in the locked or unlocked positions. In the open position of the locking disk 250 , the pawl 300 will be aligned with the window 270 .
[0061] Located rearward of the locking disk 250 is at least one gearbox 400 , illustrated in FIG. 26, and a motor 450 , illustrated in FIG. 27. The gearbox 400 is preferably a planetary gearbox. The motor 450 is preferably a 12 volt DC motor. The motor 450 is located within the motor containing portion 106 of the motor housing 100 , and is powered through electrical contacts passing through the window 110 . The motor 450 is connected through a sungear 500 to the gearbox 400 , located within the gearbox containing portion 108 of the motor housing 100 . The gearbox 400 is connected to the locking disk 250 by a second sungear 500 , fitting within the aperture 262 .
[0062] Referring to FIG. 23, a roller switch 350 is illustrated. Roller switch 350 includes a cantilever 352 , terminating in a roller 354 . A contact 356 is located beneath the cantilever 352 , so that depressing cantilever 352 closes an electrical circuit, and releasing cantilever 352 opens the circuit. Electrical contacts 358 allow connection of the roller switch 350 to an electrical circuit. Each of the two roller switches 350 is located adjacent to the locking disk 250 , so that the roller 354 abuts the locking disk's bearing surface 266 . The contacts 358 are adjacent to the windows 78 . Cantilever 352 is depressed unless the roller 354 has engaged one of the cutouts 268 . Therefore, the cantilever 352 of the roller switch 350 a is released when the locking disk 250 is in the locked position, and the cantilever 352 of the roller switch 350 b is released when the locking disk 250 is in the open position. Both cantilevers 352 are depressed when the locking disk 250 is in the unlocked position. Therefore, a distinct signal is generated designating the locking disk's locked, unlocked, and open positions.
[0063] Operation of the latch 10 is best illustrated in FIGS. 28 - 30 . The latch 10 may be operated either manually or by the motor 450 . In the locked position, illustrated in FIG. 28, the locking disk 250 is rotated so that the window 270 is 90° to the pawl 300 , the roller switch 350 engages one cutout 268 so that it is open, and the deadstop lug 264 is at one end of the slot 118 . The keeper is secured between the pawl's arm 304 and the pawl nest 66 . The pawl's locking disk engaging tooth 302 abuts the locking disk 250 , thereby securing the pawl 300 in the latched position.
[0064] To operate the latch 10 manually, a key is first inserted into the key slot 152 of the lockplug 150 . The wafers 158 retract as the key is inserted, allowing the lockplug 150 to rotate. The key is rotated clockwise. The lockplug driver 200 will engage the driver post 254 , rotating the locking disk 250 . If merely unlocking the latch 10 is desired, the rotation may stop anywhere in the unlocked range, such as illustrated in FIG. 29. As the locking disk 250 is rotated from the locked to the unlocked positions, the cantilever 352 of roller switch 350 a is depressed, so that both roller switches 350 are closed. The pawl 300 remains secured in the latched position.
[0065] Once the locking disk 250 is rotated to the unlocked position illustrated in FIG. 30, the window 270 is adjacent to pawl 300 , thereby permitting the pawl 300 to rotate from the latched to the unlatched position, releasing the keeper. The deadstop lug 264 reaches the opposite end of slot 118 , preventing further rotation of the locking disk 250 . The cantilever 352 of roller switch 350 b is released, opening the roller switch 350 b . As force is released from the key, the lockplug 150 and lockplug driver 200 rotate under spring pressure to their central position wherein the wafers 158 engage the recess 64 , allowing removal of the key. The locking disk 250 will be spring-biased away from the open position, but will be secured in the open position by abutting pawl 300 .
[0066] The latch may be closed by merely slamming it shut. The keeper will push against the arm 306 of the pawl 300 , thereby rotating the pawl 300 into the latched position. Once the pawl 300 is in the latched position, the keeper will be secured between the pawl nest 66 and pawl's arm 304 . The locking disk 250 is now free to rotate to the unlocked position of FIG. 29 under spring pressure. Both roller switches 350 are depressed, signaling the latch's unlocked position.
[0067] To manually move the locking disk 250 from the unlocked position to the locked position, a key is first inserted into the key slot 152 of the lockplug 150 . The wafers 158 retract as the key is inserted, allowing the lockplug 150 to rotate. The key is rotated counterclockwise. For the first 45° of rotation, the lockplug driver 200 will rotate without engaging the driver post 254 . For the second 45° of rotation, the end of slot 214 will abut the driver post 254 , so that the lockplug driver 200 will rotate the locking disk 250 . Once the locked position is reached, the deadstop lug 264 reaches the end of slot 118 , preventing further rotation of the locking disk 250 . The cantilever 352 of roller switch 350 a is released, opening the roller switch 350 a . As force is released from the key, the lockplug 150 and lockplug driver 200 rotate under spring pressure to their central position wherein the wafers 158 engage the recess 64 , allowing removal of the key.
[0068] Operation of the latch using the motor 450 is accomplished through a combination of switches indicating the desired action of the user, and the signals from the roller switches 350 a , 350 b indicating the present state of the latch 10 . These inputs can, for example, be directed to a programmable logic controller (PLC) which then controls the flow of electricity to the motor 450 . The following illustration assumes a dashboard mounted switch for moving the locking disk 250 between the unlocked and open positions only, and a remote key switch for moving the locking disk 250 between the locked and unlocked positions.
[0069] When the latch 10 is unlocked, both roller switches 350 a , 350 b will be closed. When the PLC receives a signal from either switch instructing it to open the latch 10 , it will activate the motor 450 until the roller switch 350 b is open, signaling that the latch 10 is now open. When the PLC receives a signal from the key switch instructing it to lock the latch 10 , it will activate the motor 450 , supplying power to rotate the motor 450 in the opposite direction, until the roller switch 350 a is open, signaling that the latch 10 is locked.
[0070] When the latch 10 is locked, and the PLC receives a signal from the dashboard switch instructing it to open the latch 10 , the PLC will not open the latch 10 , because the roller switches 350 a , 350 b will signal that the latch 10 is locked.
[0071] When the latch 10 is locked, and the PLC receives a signal from the key switch instructing it to unlock the latch 10 , the PLC will activate the motor 450 until the roller switch 350 a is closed. Similarly, when the latch 10 is locked, and the PLC receives a signal from the key switch instructing it to open the latch 10 , it will actuate the motor 450 until the roller switch 350 b is open.
[0072] Any time the latch 10 is manually operated, the motor 450 will simply rotate with the locking disk 250 as the force is transmitted through the gearbox 400 . However, throughout electronic operation of the latch 10 , the driver post 254 will move within the slot 214 without ever rotating the lockplug driver 200 or lockplug 150 .
[0073] It is to be understood that the invention is not limited to the preferred embodiments described herein, but encompasses all embodiments within the scope of the following claims.
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The present invention is directed to a latch that includes a housing, a pawl pivotally supported by the housing and movable between a latched position and an unlatched position, a spring biasing the pawl toward the unlatched position, and a locking member being rotationally movable about an axis of rotation between an open position and a locked position. The locking member interferes with the movement of the pawl such that the pawl is maintained in the latched position when the pawl is in the latched position and the locking member is in the locked position. The locking member allows the pawl to move to the unlatched position when the locking member is in the open position. The latch may further include a motor housing, a lockplug, a lockplug member, at least one roller switch, at least one gearbox, and a motor.
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This is a divisional of Ser. No. 07/363,006, filed June 8, 1989, Now U.S. Pat. No. 4,934,774.
FIELD OF THE INVENTION
This invention relates to optical waveguides and methods for their manufacture.
BACKGROUND OF THE INVENTION
Planar optical waveguides are required for optical interconnection in integrated optical and optoelectronic devices. The methods used to manufacture such waveguides must be compatible with semiconductor processing methods used to manufacture other parts of the integrated devices.
Planar optical waveguides have been made by depositing a photosensitive monomer on a substrate and selectively exposing the deposited monomer to ultraviolet (UV) radiation. The UV radiation polymerizes the exposed monomer to provide polymer regions having a relatively high refractive index bounded by monomer regions having a relatively low refractive index. A further monomer layer is generally deposited over the partially polymerized layer for protection against surface flaws and contaminants which could couple light out of the polymerized regions. Unfortunately, the waveguides made by this method are unstable at the high temperatures which are used in some semiconductor processing methods. Consequently, all high temperature processing steps must be completed before the waveguides are defined. Moreover, this method generally requires two or more deposition steps.
Planar optical waveguides have also been made by depositing or growing a first layer of Si0 2 on a substrate, depositing a layer of Si 3 N 4 on the first layer of Si0 2 , depositing a second layer of Si0 2 on the Si 3 N 4 layer, and selectively removing a partial thickness of the second Si0 2 layer in selected regions to lower the effective refractive index of the underlying Si 3 N 4 layer in those regions. This method requires three deposition or growth steps and one etch back step, all of which must be carefully controlled for satisfactory results.
Silicon-based planar optical waveguides have also been made by depositing or growing a first layer of undoped Si0 2 on a substrate, depositing P-doped Si0 2 on the layer of undoped Si0 2 , selectively removing regions of the P-doped Si0 2 layer to expose regions of the first layer of undoped Si0 2 , and depositing a second layer of undoped Si0 2 on the exposed regions of the first layer of undoped Si0 2 and on the remaining regions of P-doped Si0 2 . The regions of P-doped Si0 2 have a higher refractive index than the surrounding regions of undoped Si0 2 . This method also requires three deposition or growth steps and one etch back step, all of which must be carefully controlled for satisfactory results.
In U.S. Pat. No. 4,585,299, Robert J. Strain discloses a method for making silica-based planar optical waveguides in which boron, phosphorus, arsenic or germanium is implanted into a silicon substrate through a first mask and the substrate is oxidized through a second mask to provide a patterned Si0 2 layer which incorporates the implanted dopant. The implanted dopant raises the refractive index of a central region of the Si0 2 layer to provide a waveguide. This patent suggests that migration of the dopant during the oxide growth may be a problem.
Silicon-based planar optical waveguides have also been made by depositing or growing a layer of Si0 2 on a substrate and selectively bombarding the Si0 2 with H or B ions to define regions having a relatively high refractive index bounded by regions having a relatively low refractive index. The implantation process causes localized compaction of the Si0 2 which locally increases the refractive index of the Si0 2 . The presence of the implanted H or B ions may also modify the refractive index of the implanted Si0 2 . Unfortunately, the Si0 2 is decompacted and the implanted H or B ions are redistributed by diffusion in the Si0 2 layer if the waveguides are subjected to subsequent high temperature processing steps. The decompaction of the Si0 2 and the migration of the implanted H or B ions degrades the refractive index profile defined by the implantation process. Consequently, all high temperature processing steps must be completed before the waveguides are defined.
SUMMARY OF THE INVENTION
This invention seeks to obviate or mitigate problems with known planar optical waveguides and methods for their manufacture as described above.
One aspect of the invention provides an optical waveguide comprising a substrate and a layer of Si0 2 on the substrate. The layer of Si0 2 comprises a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index.
Another aspect of the invention provides a method for making an optical waveguide. The method comprises the steps of forming a layer of Si0 2 on the substrate and implanting a region of the Si0 2 layer with Si ions to define a region having an elevated refractive index surrounded by a region having a lower refractive index.
The optical waveguide according to the invention is stable at the high temperatures required for many semiconductor processing methods. Sample waveguides were annealed at 1100 degress Celsius in a non-oxidizing ambient for 12 hours without loss of definition of the refractive index profile. However, high temperature processing in an oxidizing ambient does cause loss of definition of the refractive index profile.
The method according to the invention requires only a single deposition or growth step, and no etch back step. Consequently this method is relatively simple and easy to control. Moreover, the method is compatible with standard semiconductor processing methods, and can be performed using readily available semiconductor processing equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described below by way of example only. The description refers to the attached drawings, in which:
FIGS. 1a, 1b and 1c are cross-sectional views of an optical waveguide according to an embodiment of the invention at successive stages of its manufacture by a method according to a first embodiment of the invention;
FIG. 2 is a plot of refractive index versus depth for the optical waveguide of FIG. 1; and
FIGS. 3a, 3b, and 3c are cross-sectional views of an optical waveguide according to an embodiment of the invention at successive stages of its manufacture by a method according to a second embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
In a method according to a first embodiment of the invention for making an optical waveguide, a layer 10 of Si0 2 is grown by steam oxidation of a <100> Si substrate 12 to form the structure shown in FIG. 1a. The steam oxidation is performed at 950 degrees Celsius and at atmospheric pressure to provide an Si0 2 layer approximately 710 nm thick.
A layer 14 of Si 3 N 4 approximately 2 microns thick is deposited on the Si0 2 layer, and defined using conventional photolithographic techniques to provide an opening 16 through the Si 3 N 4 layer 14 where a waveguide channel is desired. The resulting structure, shown in FIG. 1b, is inserted into conventional ion implantation equipment, where it is subjected to a dose of Si ions 18 at an implant dose of 4×10 16 cm -2 and an implantation energy of 40 keV. The Si 3 N 4 layer 14 acts as an ion implantation mask to provide selective implantation of the Si ions 18 into the Si0 2 layer 14 only through the opening 16.
The Si 3 N 4 layer 14 is removed using conventional techniques for the selective removal of Si 3 N 4 to leave the layer 10 of Si0 2 which now comprises an implanted region 20 containing a stoichiometric excess of Si as shown in FIG. 1c. The stoichiometric excess of Si as a function of depth approximates a Gaussian distribution function. The refractive index of the implanted region 20 is elevated by the presence of the excess Si in proportion to the local concentration of the excess Si. Thus, the excess Si defines a graded refractive index profile which defines a region having an elevated refractive index surrounded by a region having a lower refractive index.
FIG. 2 illustrates the refractive index profile of the implanted optical waveguide which may be measured using conventional etch back techniques combined with conventional ellipsometric refractive index measurements.
Waveguides made by methods similar to the method described above have been annealed in an inert ambient at 1100 degrees Celsius for 12 hours without detectable changes in the refractive index profile. These results indicate that although a minor proportion of the refractive index increase may be due to compaction of the Si0 2 , a mechanism which is reversed at high temperatures, most of the refractive index increase must be due to a different mechanism which is stable at high temperatures. It is believed that the increased refractive index of the Si-implanted Si0 2 is primarily due to the formation of Si--Si bonds which are stable at high temperatures. Thus, high temperature semiconductor processing steps which are conducted in an inert ambient may follow the formation of waveguides by the above method without degradation of the waveguide structure.
However, exposure of the implanted layers to high temperature processing in an oxidizing ambient reverses the refractive index increase due to implantation, probably because the presence of excess oxygen at elevated temperatures disrupts Si--Si bonds formed during implantation to form further Si0 2 . This effect can be used in an alternative method for making an optical waveguide as described below.
In a method according to a second embodiment, an Si0 2 layer 10 is grown as in the first embodiment. The implantation masking Si 3 N 4 layer 14 of the first embodiment is omitted, and the entire Si0 2 layer 10 is implanted with Si ions to form a refractive index profile, as shown in FIG. 3a. A layer 14 of Si 3 N 4 is then deposited on the Si0 2 layer 10 and defined using conventional photolithographic techniques so that the Si 3 N 4 layer 14 remains only over regions of the Si0 2 layer 10 where a waveguide is desired, as shown in FIG. 3b. The resulting structure is then heated in an oxidizing ambient to oxidize the implanted Si in regions of the Si0 2 layer 10 which are not covered by the remaining Si 3 N 4 layer 14 to erase the refractive index profile in those regions, as shown in FIG. 3c. The Si 3 N 4 layer 14 acts as an oxidation-resistant mask to prevent oxidation of the implanted Si and erasure of the refractive index profile in the regions where a waveguide is desired.
The methods described above may be modified by growing the Si0 2 layer 10 on Si substrates of different orientations and at different temperatures of pressures. Pressures exceeding atmospheric pressure may be required where a thick Si0 2 layer is desired. The SiO 2 layer may be formed on Si substrates or on substrates of materials such as III-V semiconductors by processes other than thermal growth such as chemical vapour deposition.
The Si0 2 thickness, the implantation energy and implantation dose may be modified to change the depth and refractive index profile of the resulting waveguide. For example, the implantation energy may range from 3 keV to 400 keV, and the implantation dose may range from 1×10 14 cm -2 to 2×10 17 cm -2 .
Non-Gaussian refractive index profiles can be obtained by performing a series of implantations at different implantation energies and optionally at different implantation doses. Successive implantations can be performed through different implantation masks to provide different refractive index profiles in different regions of the Si0 2 layer 10. A series of implantations through a common implantation mask can be used to provide a high refractive index well which extends to the surface of the Si0 2 layer 10 for surface coupling of a waveguide to an optical fiber or an optical device.
Other masking materials, such as polysilicon or Al may be used during implantation, and the thickness of the masking material should be selected to be at least three to five times the projected range of Si ions in the selected masking material at the selected implantation energy. These and other modifications are within the scope of the invention as claimed below.
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An optical waveguide is made by forming a layer of SiO 2 on a substrate and implanting a region of the SiO 2 layer with Si ions to define a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index. The resulting optical waveguide is stable at the high temperatures required for many semiconductor processing methods, and is useful for optical interconnection in integrated optical and optoelectronic devices.
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[0001] The present invention relates to the phytocannabinoid tetrahydrocannabivarin (THCV) for use in the protection of pancreatic islet cells. Preferably the pancreatic islet cells to be protected are beta cells. More preferably the protection of the pancreatic islet cells maintains insulin production at levels which are able to substantially control or improve control of blood glucose levels in a patient.
DEFINITIONS
[0002] In this specification the following terms are used and are intended to have the following meanings/definitions:
[0003] “Cannabinoids” are a group of compounds including the endocannabinoids, the phytocannabinoids and those which are neither endocannabinoids or phytocannabinoids, hereafter “syntho-cannabinoids”.
[0004] “Endocannabinoids” are endogenous cannabinoids, which are high affinity ligands of CB1 and CB2 receptors.
[0005] “Phytocannabinoids” are cannabinoids that originate in nature and can be found in the cannabis plant. The phytocannabinoids can be present in an extract including a botanical drug substance, isolated, or reproduced synthetically.
[0006] “Syntho-cannabinoids” are those compounds capable of interacting with the cannabinoid receptors (CB1 and/or CB2) but are not found endogenously or in the cannabis plant. Examples include WIN 55212 and rimonabant.
[0007] An “isolated phytocannabinoid” is one which has been extracted from the cannabis plant and purified to such an extent that all the additional components such as secondary and minor cannabinoids and the non-cannabinoid fraction have been removed.
[0008] A “synthetic cannabinoid” is one which has been produced by chemical synthesis this term includes modifying an isolated phytocannabinoid, by for example forming a pharmaceutically acceptable salt thereof.
[0009] A “botanical drug substance” or “BDS” is defined in the Guidance for Industry Botanical Drug Products Draft Guidance, August 2000, US Department of Health and Human Services, Food and Drug Administration Centre for Drug Evaluation and Research as: “A drug derived from one or more plants, algae, or microscopic fungi. It is prepared from botanical raw materials by one or more of the following processes: pulverisation, decoction, expression, aqueous extraction, ethanolic extraction or other similar processes.” A botanical drug substance does not include a highly purified or chemically modified substance derived from natural sources. Thus, in the case of cannabis, BDS derived from cannabis plants do not include highly purified Pharmacopoeial grade cannabinoids.
[0010] In the present invention a BDS is considered to have two components: the phytocannabinoid-containing component and the non-phytocannabinoid containing component. Preferably the phytocannabinoid-containing component is the larger component comprising greater than 50% (w/w) of the total BDS and the non-phytocannabinoid containing component is the smaller component comprising less than 50% (w/w) of the total BDS.
[0011] The amount of phytocannabinoid-containing component in the BDS may be greater than 55%, through 60%, 65%, 70%, 75%, 80% to 85% or more of the total extract. The actual amount is likely to depend on the starting material used and the method of extraction used.
[0012] The “principle phytocannabinoid” in a BDS is the phytocannabinoid that is present in an amount that is higher than that of the other phytocannabinoids. Preferably the principle phytocannabinoid is present in an amount greater than 40% (w/w) of the total extract. More preferably the principle phytocannabinoid is present in an amount greater than 50% (w/w) of the total extract. More preferably still the principle phytocannabinoid is present in an amount greater than 60% (w/w) of the total extract.
[0013] The amount of the principle phytocannabinoid in the BDS is preferably greater than 50% of the phytocannabinoid-containing fraction, more preferably still greater than 55% of the phytocannabinoid-containing fraction, and more preferably still greater than 60% through 65%, 70%, 75%, 80%, 85%, 90% and 95% of the phytocannabinoid-containing fraction.
[0014] The “secondary phytocannabinoid/s” in a BDS is the phytocannabinoid/s that is/are present in significant proportions. Preferably the secondary phytocannabinoid is present in an amount greater than 5% (w/w) of the total extract, more preferably greater than 10% (w/w) of the total extract, more preferably still greater than 15% (w/w) of the total extract. Some BDS's will have two or more secondary phytocannabinoids that are present in significant amounts. However not all BDS's will have a secondary phytocannabinoid.
[0015] The “minor phytocannabinoid/s” in a BDS can be described as the remainder of all the phytocannabinoid components once the principle and secondary phytocannabinoids are accounted for. Preferably the minor phytocannabinoids are present in total in an amount of less than 5% (w/w) of the total extract, and most preferably the minor phytocannabinoid is present in an amount less than 2% (w/w) of the total extract.
[0016] The term “consisting essentially of” is limited to the phytocannabinoids which are specified, it does not exclude non-cannabinoid components that may also be present.
[0017] Typically the non-phytocannabinoid containing component of the BDS comprises terpenes, sterols, triglycerides, alkanes, squalenes, tocopherols and carotenoids.
[0018] These compounds may play an important role in the pharmacology of the BDS either alone or in combination with the phytocannabinoid.
[0019] The “terpene fraction” may be of significance and can be broken down by the type of terpene: monoterpene or sesquiterpene. These terpene components can be further defined in a similar manner to the cannabinoids.
[0020] The amount of non-phytocannabinoid containing component in the BDS may be less than 45%, through 40%, 35%, 30%, 25%, 20% to 15% or less of the total extract. The actual amount is likely to depend on the starting material used and the method of extraction used.
[0021] The “principle monoterpene/s” in a BDS is the monoterpene that is present in an amount that is higher than that of the other monoterpenes. Preferably the principle monoterpene/s is present in an amount greater than 20% (w/w) of the total terpene content. More preferably the principle monoterpene is present in an amount greater than 30% (w/w) of the total terpene content, more preferably still greater than 40% (w/w) of the total terpene content, and more preferably still greater than 50% (w/w) of the total terpene content. The principle monoterpene is preferably a myrcene or pinene. In some cases there may be two principle monoterpenes. Where this is the case the principle monoterpenes are preferably a pinene and/or a myrcene.
[0022] The “principle sesquiterpene” in a BDS is the sesquiterpene that is present in an amount that is higher than all the other sesquiterpenes. Preferably the principle sesquiterpene is present in an amount greater than 20% (w/w) of the total terpene content, more preferably still greater than 30% (w/w) of the total terpene content. The principle sesquiterpene is preferably a caryophyllene and/or a humulene.
[0023] The sesquiterpene components may have a “secondary sesquiterpene”. The secondary sesquiterpene is preferably a caryophyllene, which is preferably present at an amount greater than 5% (w/w) of the total terpene content, more preferably the secondary sesquiterpene is present at an amount greater than 10% (w/w) of the total terpene content.
[0024] The secondary sesquiterpene is preferably a humulene which is preferably present at an amount greater than 5% (w/w) of the total terpene content, more preferably the secondary sesquiterpene is present at an amount greater than 10% (w/w) of the total terpene content.
[0025] Alternatively botanical extracts may be prepared by introducing isolated phytocannabinoids or their synthetic equivalent into a non-cannabinoid plant fraction as can be obtained from a zero cannabinoid plant or one or more non-cannabinoid components found in the cannabis plant such as terpenes.
[0026] The structure of the phytocannabinoid THCV is shown below:
[0000]
[0027] Phytocannabinoids can be found as either the neutral (decarboxylated form) or the carboxylic acid form depending on the method used to extract the cannabinoids. For example it is known that heating the carboxylic acid form will cause most of the carboxylic acid form to decarboxylate into the neutral form.
[0028] Where a synthetic phytocannabinoid is used the term is intended to include compounds, metabolites or derivatives thereof, and pharmaceutically acceptable salts of such compounds.
[0029] The term “pharmaceutically acceptable salts” refers to salts or esters prepared from pharmaceutically acceptable non-toxic bases or acids, including inorganic bases or acids and organic bases or acids, as would be well known to persons skilled in the art. Many suitable inorganic and organic bases are known in the art.
[0030] For the purpose of this invention the term “treatment” is intended to encompass protection of the pancreatic islet cells and a therapeutically effective amount of THCV is an amount that provides a degree of protection.
BACKGROUND TO THE INVENTION
[0031] The pancreas is a gland in the digestive system of vertebrates and produces important hormones including insulin, glucagon and somatostatin as well as being a digestive organ secreting digestive enzymes to assist in the absorption of nutrients.
[0032] The pancreas comprises two different types of tissue; the islets of Langerhans which produce and secrete hormones including insulin and the pancreatic acini which produce and secrete digestive enzymes.
[0033] Four main cell types exist in the islets: alpha cells secrete glucagon, which increases glucose concentration in the blood; beta cells secrete insulin, which decrease glucose in the blood; delta cells secrete somatostatin, which regulates alpha and beta cells; and PP cells which secrete pancreatic polypeptide.
[0034] The islets of Langerhans play an imperative role in glucose metabolism and regulation of blood glucose concentration.
[0035] Diabetes mellitus is a disease that is caused by either or both deficiency or diminished effectiveness of the insulin which is produced by the pancreatic islets. It is characterised by hyperglycemia, unbalanced metabolism and other conditions predominantly affecting the vascular structures.
[0036] The main types of diabetes mellitus are: Type 1 diabetes mellitus, which results from the body's failure to produce sufficient insulin and Type 2 diabetes mellitus which results from resistance to insulin, often initially with normal or increased levels of circulating insulin, though ultimately a failure to produce sufficient insulin.
[0037] Type 1 diabetes mellitus is a form of diabetes that results from autoimmune destruction of insulin-producing beta cells of the pancreas. The subsequent lack of insulin leads to increased blood glucose and urinary excretion of glucose.
[0038] Other types of diabetes mellitus include: Gestational diabetes where pregnant women who have never had diabetes before but who have high blood sugar (glucose) levels during pregnancy develop diabetes. This type of diabetes affects about 4% of all pregnant women. It may precede development of type 2 diabetes mellitus.
[0039] Secondary diabetes: accounts for approximately 1-2% of patients with diabetes mellitus. Causes include: Pancreatic diseases such as cystic fibrosis, chronic pancreatitis, pancreatectomy, carcinoma of the pancreas; Endocrine diseases such as Cushing's syndrome, acromegaly, thyrotoxicosis, phaeochromocytoma, glucagonoma; Drug-induced diabetes such as thiazide diuretics, corticosteroids, atypical antipsychotics, antiretroviral protease inhibitors; congenital lipodystrophy; Acanthosis nigricans; and genetic causes such as Wolfram syndrome, Friedreich's ataxia, dystrophia myotonica, haemochromatosis, and glycogen storage diseases.
[0040] Some patients with type 2 diabetes require insulin so the old terms of insulin-dependent diabetes mellitus for type 1 diabetes and non-insulin dependent diabetes mellitus for type 2 diabetes are inappropriate.
[0041] Type 1 diabetes mellitus accounts for less than 15% of diabetics. It is usually a juvenile onset disease but may occur at any age. It may be associated with other autoimmune diseases and is characterised by insulin deficiency.
[0042] The cause of type 1 diabetes mellitus is unknown however it has been discovered that a gene determines islet sensitivity to damage from viruses.
[0043] Patients with type 1 diabetes mellitus always need insulin treatment and are prone to ketoacidosis. Diabetic ketoacidosis occurs when the body cannot use glucose as a fuel source because there is no insulin or not enough insulin. Fat is used for fuel instead and the by-products of fat breakdown, called ketones, build up in the body.
[0044] Symptoms of ketoacidosis include: deep, rapid breathing; dry skin and mouth; flushed face; fruity smelling breath; nausea, vomiting and stomach pain. If the ketoacidosis is not treated decreased consciousness may occur which may worsen to a coma or even death.
[0045] Patients with type 2 diabetes mellitus account for more than 85% of all cases of diabetes mellitus. Type 2 diabetics are usually older at presentation (>30 years of age) but this disease is increasingly being diagnosed in children and adolescents.
[0046] Type 2 diabetes is often associated with excess body weight and physical inactivity and is caused by impaired insulin secretion and insulin resistance. These two defects interact. Thus to combat insulin resistance, the islet cells produce more insulin but over time this overproduction results in further compromising islet cell integrity. At the time of diagnosis of diabetes, pancreatic islet cell mass will have been reduced by at least 50%. Type 2 diabetes mellitus has a gradual onset and may eventually require insulin treatment.
[0047] Metabolic syndrome is thought of as a precursor to type 2 diabetes. This syndrome is poorly defined and represents a heterogeneous collection of various propensities to diabetes. It has been suggested that lifestyle-intervention and treating metabolic manifestations of this pre-diabetic state can reduce the chance of progression to frank diabetes and the risk of complications.
[0048] The aims of current treatment are the avoidance of complications. Strict plasma glucose control reduces renal, neurological and retinal damage. A balance is required for each patient between low blood glucose readings and the risk of hypoglycemia.
[0049] The prognosis has improved considerably with the development of insulin therapies although many diabetics develop blindness, end-stage renal disease and, in some cases, early death. Controlling blood glucose, lipids, blood pressure and weight are important factors and predict the development of long-term macrovascular and microvascular complications.
[0050] Mortality is two to three times higher among people with type 2 diabetes than in the general population. Indeed 75% of people with type 2 diabetes die of heart disease and 15% of stroke. The mortality rate from cardiovascular disease is up to five times higher in people with diabetes than in people without diabetes.
[0051] Treatment goals for type 1 diabetes mellitus is to minimize any elevation of blood sugar (glucose) without causing abnormally low levels of blood sugar. Type 1 diabetes mellitus is therefore treated with insulin, exercise, and dietary modification.
[0052] Type 2 diabetes mellitus is treated first with weight reduction, dietary modification, and exercise. When these measures fail to control the elevated blood sugars, oral medications are used. If oral medications are still insufficient, treatment with insulin or other medications are considered.
[0053] Several different types of medicine can be used to treat type 2 diabetes; a combination of two or more medicines may be required to control the blood glucose level. Many provide merely symptomatic relief such as weight reduction, others provide disease modifying effects.
[0054] Typical anti-diabetic drugs include: Metformin; Sulphonylureas; Glitazones; Gliptins; GLP-1 agonists; Acarbose; Nateglinide and repaglinide. SGLT-2 inhibitors are also being developed.
[0055] Metformin is often the first medicine that is recommended to treat type 2 diabetes. It works by reducing the amount of glucose that the liver releases into the bloodstream. It also makes the body's cells more responsive to insulin. Side effects of metformin include nausea, vomiting and diarrhea.
[0056] Sulphonylureas increase the amount of insulin that is produced by the pancreas. Examples of sulphonylureas include: glibenclamide; gliclazide; glimerpirizide; glipizide; and gliquidone. Sulphonylureas can increase the risk of hypoglycaemia (low blood glucose) because they increase the amount of circulating insulin. Sulphonylureas may cause other side effects including weight gain, nausea and diarrhea.
[0057] Glitazones such as thiazolidinedione medicines (pioglitazone) make cells more sensitive to insulin so that more glucose is taken from the blood. They are not often used alone, but are usually used in addition to metformin or sulphonylureas, or both. They may cause weight gain and water retention. Another thiazolidinedione, rosiglitazone, has been withdrawn from use because of the increased risk of cardiovascular disorders, including heart attack and heart failure.
[0058] Gliptins are DPP-4 inhibitors which work by inhibiting the breakdown of a naturally occurring hormone called GLP-1. GLP-1 helps the body produce insulin in response to high blood glucose levels, but is rapidly broken down. By preventing this breakdown, the gliptins (such as sitagliptin and vildagliptin) act to prevent high blood glucose levels, but do not result in episodes of hypoglycaemia.
[0059] GLP-1 agonists such as Exenatide are an injectable treatment that acts in a similar way to the natural hormone GLP-1 but have longer plasma half-lives. They are injected twice a day and boosts insulin production when there are high blood glucose levels, reducing blood glucose without the risk of hypoglycaemic episodes. They also lead to modest weight loss in many people who take them. They are mainly used in people on metformin and/or sulphonylurea who are obese (with a BMI of 35 or above).
[0060] Acarbose helps prevent blood glucose level from increasing too much after a meal. It slows down the rate at which the digestive system breaks down carbohydrates into glucose. Acarbose is not often used to treat type 2 diabetes because it usually causes side effects, such as bloating, diarrhoea and meteorism.
[0061] Nateglinide and repaglinide stimulate the release of insulin by the pancreas. They are not commonly used but may be an option if meals are eaten at irregular times. This is because their effects do not last very long, but they are effective when taken just before a meal. Nateglinide and repaglinide can cause side effects, such as weight gain and hypoglycaemia (low blood glucose).
[0062] The patent GB 2434097 discusses the properties of THCV. The patent describes receptor binding studies which show that THCV is a CB-1 receptor neutral antagonist, as such the patent claims using THCV to treat conditions benefitting from neutral antagonism of the CB-1 receptor. Such conditions include obesity, schizophrenia, epilepsy and obesity associated with type 2 diabetes (a symptomatic effect of type 2 diabetes).
[0063] The application US 2007/0099987 discusses the use of the cannabinoid cannabidiol (CBD) in the prevention or treatment of type 1 diabetes and / or insulitis.
[0064] The application WO 2009/007697 describes a pharmaceutical formulation which comprises a ratioed mix of the cannabinoids THCV and CBD based on the pharmacology of the respective compounds.
[0065] The application WO 2009/093018 discusses the use of a combination of CBD and THCV to manage or treat metabolic syndrome or a cluster of disorders which commonly occur together including: type I or type II diabetes, obesity, dyslipidemia, or cardiovascular disease. It is described that these conditions are managed or treated by controlling cholesterol levels (a CBD effect) and increasing energy expenditure in a subject (a THCV effect).
[0066] The application WO 2007/032962 describes an intranasal formulation comprising tricyclic cannabinoids. Whilst a THCV formulation is envisaged there is no specific disclosure of the use of this compound for treatment of a particular disorder. All exemplification relates specifically to the use of THC.
[0067] Indeed none of the above documents teach or suggest that THCV can be used alone or in combination to protect the pancreatic islet cells and thereby maintain insulin function. This protective effect enables a formulation comprising or consisting of THCV to be used to treat in a disease modifying manner (as opposed to providing symptomatic relief such as weight reduction or blood glucose control), diseases such as diabetes. Thus in addition to treating type 1 diabetes it is also possible to more effectively manage type 2 diabetes and treat pre-diabetic patients to prevent the onset of diabetes and other metabolic related conditions.
[0068] A critical issue when treating human subjects is the evaluation of islet β-cell mass and function in response to treatment. A significant limitation of interventional trials in humans is that there are no “gold standard” methods to directly measure β-cell mass in vivo. Newer imaging techniques like positron emission tomography, magnetic resonance imaging, scintigraphy, or neurofunctional imaging approach are undergoing development as non-invasive methods of islet β-cell mass measurement.
[0069] Metabolic tests have been routinely used as surrogate markers, and studies have shown that acute insulin response to arginine, glucose and glucose-potentiated and arginine-induced insulin secretion can be used as tests for estimation of islet β-cell mass. A well-validated and practical means of quantifying insulin secretion in vivo is measurement of C-peptide levels under standardized conditions, which has low variability and high reproducibility, making it a good and reliable marker. In fact, the recommendation of an expert panel convened by the American Diabetes Association was that C-peptide response (CPR) is the most appropriate measure of function and clinical end point of intervention in human clinical trials.
[0070] Type 2 diabetes is associated with insulin resistance and reduced insulin secretion, which results in hyperglycaemia. This can then lead to diabetic complications such as retinopathy, neuropathy, nephropathy and cardiovascular disease. Although insulin resistance may be present earlier in the progression of the disease, it is now generally accepted that it is the deterioration in insulin-secretory function that leads to hyperglycaemia.
[0071] This reduction in insulin secretion in type 2 diabetes is due to both islet β-cell dysfunction and death.
[0072] Interventions that maintain the normal function and protect the pancreatic islet β-cells from death are crucial in the treatment of type 2 diabetes so that fasting plasma glucose levels may be maintained within or approaching the normal range (between about 3.6 and 5.8 mM, or 64.8 and 104.4 mg/dL). Compounds which are found to protect islet β-cells from failure and increase or prevent the decrease of islet β-cell mass are crucial in the treatment of type 2 diabetes.
[0073] A fasting serum insulin level of greater than approximately 60 pmol/L is considered evidence of insulin resistance. Therefore maintaining fasting insulin levels at or near to this level is desirable.
[0074] A glucose tolerance test (GTT) is often used to diagnose diabetes. A fasting patient takes a 75 gram oral dose of glucose. Blood glucose levels are then measured over the following 2 hours. After 2 hours a glycaemia less than 7.8 mmol/L is considered normal, a glycaemia of between 7.8 to 11.0 mmol/dl is considered as impaired glucose tolerance and a glycaemia of greater than or equal to 11.1 mmol/dl (200 mg/dl) is considered to be diabetes mellitus
[0075] Insulin resistance is often measured using the hyperinsulinemic euglycaemic clamp. This is the gold standard for investigating and quantifying insulin resistance. It measures the amount of glucose necessary to compensate for an increased insulin level without causing hypoglycemia.
[0076] Insulin is infused at 10-120 mU per m 2 per minute. Glucose 20% is infused to maintain blood sugar levels between 5 and 5.5 mmol/l. The rate of glucose infusion is determined by checking the blood sugar levels every 5 to 10 minutes. Low-dose insulin infusions are more useful for assessing the response of the liver, whereas high-dose insulin infusions are useful for assessing peripheral (i.e., muscle and fat) insulin action.
[0077] The rate of glucose infusion during the last 30 minutes of the test determines insulin sensitivity. If high levels (7.5 mg/min or higher) are required, the patient is insulin-sensitive.
[0078] Very low levels (4.0 mg/min or lower) indicate that the body is resistant to insulin action. Levels between 4.0 and 7.5 mg/min are not definitive and suggest “impaired glucose tolerance,” an early sign of insulin resistance.
[0079] It is an object of the present invention to provide a means of protecting the pancreatic islet cells. In providing such protection of the islets conditions which are caused by damage or dysfunction of the islets such as diabetes mellitus can be treated at an earlier stage or a different treatment strategy can be employed.
[0080] However, surprisingly it has been observed in a rodent model of diabetes, that THCV (CB1 neutral antagonist) is able to protect the insulin-producing cells of the pancreatic islets and give rise to a reduction in fasting insulin indicative of improved insulin resistance. Islet cell preservation is seen as a highly desirable feature of a new anti-diabetic medicine.
BRIEF SUMMARY OF THE DISCLOSURE
[0081] In accordance with a first aspect of the present invention there is provided the phytocannabinoid tetrahydrocannabivarin (THCV) for use in the protection of pancreatic islet cells.
[0082] Preferably the pancreatic islet cells to be protected are beta cells and the protection of the pancreatic islet cells maintains insulin production at levels which are able to substantially control or improve control of blood glucose levels in a patient.
[0083] Preferably the protection of the pancreatic islet cells supports the treatment of diabetic or pre-diabetic patients. More preferably the patient has or is pre-disposed to type 1 diabetes. Alternatively the patient has or is pre-disposed to type 2 diabetes. Furthermore the patient which has or is pre-disposed to type 2 diabetes may have gestational diabetes.
[0084] Patients with suffer with type 2 diabetes during pregnancy or their offspring may be pre-disposed to developing this type of diabetes, therefore treatment of gestational diabetes may be a valid treatment option.
[0085] When the patient has or is pre-disposed to type 2 diabetes the THCV acts as a disease modifying treatment as opposed to merely a symptomatic treatment. In particular the symptomatic treatment is to reduce obesity.
[0086] In one embodiment the THCV is used in combination with one or more additional anti-diabetic medicines and/or one or more anti-obesity medicines. Preferably the additional anti-diabetic medicine is metformin or is from the sulphonylurea class of anti-diabetic drugs.
[0087] Other anti-diabetic medications which could be used include: glitazones; gliptins; GLP-1 agonists; acarbose; nateglinide, and SGLT-2 inhibitors. Other anti-diabetic medications are being developed.
[0088] In a further embodiment the THCV is a synthetic cannabinoid or an isolated phytocannabinoid.
[0089] In a separate embodiment the THCV is present as an extract from a cannabis plant. Preferably the extract from a cannabis plant is a botanical drug substance. More preferably the extract is substantially free of the phytocannabinoids tetrahydrocannabinol (THC) and/or cannabidiol (CBD).
[0090] A typical THCV BDS is as described in Tables 1.1 and 1.2 below:
[0000]
TABLE 1.1
Tetrahydrocannabivarin BDS amount in total and range
Amount
Range
Range
Range
THCV BDS
(% w/w)
(± 10%)
(± 25%)
(± 50%)
CBGV
0.15
0.14-0.17
0.11-0.19
0.07-0.23
CBNV
1.30
1.20-1.40
1.00-1.60
0.65-1.95
THCV
64.49
58.04-70.94
48.37-80.61
32.25-96.74
CBCV
0.65
0.59-0.72
0.49-0.81
0.33-0.98
THC-C4
0.82
0.74-0.90
0.62-1.03
0.41-1.23
CBN
0.15
0.14-0.17
0.11-0.19
0.07-0.23
THCVA
0.36
0.32-0.40
0.27-0.45
0.18-0.54
THC
13.43
12.09-14.77
10.07-16.79
7.72-20.15
Unknowns
0.58
0.52-0.64
0.44-0.73
0.29-0.87
Total
81.93
Cannabinoids
Total Non-
18.07
cannabinoids
[0091] The total phytocannabinoid containing fraction of THCV BDS comprises approximately 74-90% (w/w) of the total BDS.
[0000]
TABLE 1.2
Tetrahydrocannabivarin BDS by percentage cannabinoid
Amount
THCV BDS
(% of total cannabinoid)
CBGV
0.18
CBNV
1.59
THCV
78.71
CBCV
0.79
THC-C4
1.00
CBN
0.18
THCVA
0.44
THC
16.39
Unknowns
0.71
[0092] The amount of the principle phytocannabinoid in the THCV BDS as a percentage of the phytocannabinoid containing fraction is approximately 71-87% (w/w). The THCV BDS also has a secondary cannabinoid THC which is present at approximately 14.8-18% (w/w) of the phytocannabinoid containing fraction.
[0093] The THCV is present in a therapeutically acceptable amount, which may, for example, be between 1 mg and 2000 mg.
[0094] The human dose equivalent (HED) can be estimated using the following formula:
[0000]
HED
=
Animal
dose
(
mg
/
kg
)
multiplied
by
Animal
K
m
Human
K
m
[0000] The K m for a mouse is 3 and the K m for a human is 37.
[0095] In accordance with a second aspect of the present invention there is provided the phytocannabinoid tetrahydrocannabivarin (THCV) for use in the treatment of type 1 diabetes.
[0096] In accordance with a third aspect of the present invention there is provided the phytocannabinoid tetrahydrocannabivarin (THCV) for use as an oral anti-diabetic medication.
[0097] In accordance with a fourth aspect of the present invention there is provided the phytocannabinoid tetrahydrocannabivarin (THCV) for use as a GLP-1 agonist.
[0098] In accordance with a fifth aspect of the present invention there is provided the use of the phytocannabinoid tetrahydrocannabivarin (THCV) in the manufacture of a medicament for use in the protection of pancreatic islet cells.
[0099] In accordance with a sixth aspect of the present invention there is provided a method of treating a patient requiring protection of pancreatic islet cells comprising administering a therapeutically effective amount of phytocannabinoid tetrahydrocannabivarin (THCV) to the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0100] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
[0101] FIG. 1 shows a photograph of stained pancreatic islet cell prior to treatment;
[0102] FIG. 2 shows a photograph of stained pancreatic islet cell in vehicle treated diabetic mouse;
[0103] FIG. 3 shows a photograph of stained pancreatic islet cell in AM251treated diabetic mouse;
[0104] FIG. 4 shows a photograph of stained pancreatic islet cell in CBD treated diabetic mouse;
[0105] FIG. 5 shows a photograph of stained pancreatic islet cell in THCV treated diabetic mouse;
[0106] FIG. 6 shows the bodyweight change of the animals over the study period;
[0107] FIG. 7 shows the blood glucose concentration of the animals over a 24 hour period;
[0108] FIG. 8 shows the pancreatic islet beta cell mass in animals at the end of the study period.
[0109] FIG. 9 shows the concentration of blood glucose of animals at day 0;
[0110] FIG. 10 shows the concentration of blood glucose of animals at day 7;
[0111] FIG. 11 shows the concentration of blood glucose of animals at day 14;
[0112] FIG. 12 shows the concentration of blood glucose of animals at day 23;
[0113] FIG. 13 shows the area under the curve after animals were given an oral glucose tolerance test at day 31;
[0114] FIG. 14 shows the mean change from baseline of the concentration of insulin during an oral glucose tolerance test in the THCV treated group at Visit 5;
[0115] FIG. 15 shows the mean change from baseline of the concentration of blood glucose during an oral glucose tolerance test in the THCV treated group at Visit 5;
[0116] FIG. 16 shows the change from baseline in HOMA2 insulin sensitivity;
[0117] FIG. 17 shows the change from baseline in HOMA2 beta cell function; and
[0118] FIG. 18 shows the change from baseline in mean serum glucagon-like peptide 1 (GLP-1) levels.
DETAILED DESCRIPTION
[0119] The invention is illustrated by way of the following Examples.
[0120] Example 1 was designed to examine whether cannabidiol (CBD) and/or tetrahydrocannabivarin (THCV) are able to affect pancreatic islet cell morphology.
[0121] Example 2 looked at the effect of THCV in combination with an anti-diabetic medicament, exemplified by rosiglitazone.
[0122] Example 3 demonstrates the use of THCV in a clinical study whereby the effect of this phytocannabinoid in man is demonstrated for the first time.
EXAMPLE 1
Effect of Tetrahydrocannabivarin (THCV) and Cannabidiol (CBD) on Islet Cell Morphology and Function in Diabetic Mice
Materials and Methods
[0123] The animals used in this study were male db/db mice which were aged 7 to 8 weeks on commencement of the study. The db/db mouse is a model of obesity, diabetes, and dyslipidemia. The mice were obtained from Charles River (Italy) and fed on the Beekay Rat and Mouse Diet Number 1 throughout the study.
[0124] The animals were weighed and grouped into 8 animals per group, 4 animals per cage and dosed as described in Table 1.3 below:
[0000]
TABLE 1.3
Dosing Groups
GROUP
Dose
A
10 ml/kg Vehicle
B
10 mg/kg THCV
C
10 mg/kg AM 251
D
10 mg/kg CBD
E
Baseline measurements
[0125] The phytocannabinoids CBD (10 mg/kg) and THCV (10mg/kg) were tested along with AM 251 (10 mg/kg) which was used as a positive control.
[0126] At the start of the study the Group E animals were sacrificed and a terminal blood sample was taken. In addition four of the animals pancreases were sampled for determination of β-cell area, islet size and β-cell mass by immunoblotting.
[0127] On day 1 dosing commenced for groups A to D as outlined in Table 1.1 above. Animals were dosed daily at 17:00.
[0128] Throughout the 28 day study the animals in each group were weighed and blood samples were taken for glucose, insulin, triglycerides, HDL and total cholesterol.
[0129] On day 25 of the study the body composition of the animals was measured using DEXA scanning.
[0130] At the end of the study the animals were sacrificed and a terminal blood sample was taken. In addition four of the animals pancreases were sampled for determination of islet β-cell area, islet size and islet β-cell mass by immunoblotting.
[0131] The pancreases were stained for insulin and the pancreatic islet cells were examined under a microscope to determine the amount of insulin in the cells.
Results
[0132] The histology findings indicated that THCV caused a greater retention of insulin in the pancreatic islet than both AM251 and CBD. This finding suggests that the phytocannabinoid is islet cell protective.
[0133] FIG. 1 illustrates the pancreatic islets in the untreated group and FIGS. 2 to 5 illustrate photographs of the stained pancreatic islet cells from the different treatment groups. As can be observed in FIG. 5 the islets in the animals treated with the THCV are far darker than those in the CBD, AM251 and vehicle groups indicating that there is statistically more insulin present in the pancreatic islets.
[0134] FIG. 6 shows that the animals treated with the CBD had an increased weight gain, however the weight gain of the animals treated with the THCV and AM 251 was similar to controls and indeed food intake was slightly lower.
[0135] FIG. 7 demonstrates that the blood glucose concentration of the animals treated with THCV was more controlled during a 24 hour period. In effect there were no period of hyperglycaemia or hypoglycaemia which is indicative of stable blood glucose control.
[0136] FIG. 8 illustrates from morphological analysis that the pancreatic beta cell mass was higher in the THCV treated animals than in the vehicle and CBD and AM251 treated groups.
Conclusion
[0137] The data above demonstrate that THCV is able to induce islet cell protection in diabetic mice without having a profound reduction in blood glucose.
[0138] This finding is of real significance and leads to the conclusion that the phytocannabinoid THCV is islet cell protective and as such a significant treatment option for diabetes.
EXAMPLE 2
Effect of Tetrahudrocannabivarin (THCV) and Rosiglitazone on Plasma Glucose Levels in Diabetic Mice
Materials and Methods
[0139] The animals used in this study were male db/db mice which were aged 7 to 8 weeks on commencement of the study. The db/db mouse is a model of obesity, diabetes, and dyslipidemia. The mice were obtained from Charles River (Italy) and fed on the Beekay Rat and Mouse Diet Number 1 throughout the study.
[0140] The animals were weighed and grouped into 8 animals per group, 4 animals per cage and dosed as described in Table 1.4 below:
[0000]
TABLE 1.4
Dosing Groups
GROUP
Dose
A
10 ml/kg Vehicle
B
10 mg/kg THCV
C
10 mg/kg Rosiglitazone
D
10 mg/kg Sitagliptin
E
10 mg/kg THCV + 10 mg/kg Rosiglitazone
[0141] Sitagliptin is an anti-diabetic drug and was used as a positive control.
[0142] On day 1 dosing commenced for groups A to E as outlined in Table 1.4 above. Animals were dosed daily at 17:00.
[0143] At set time periods: day 0, day 7, day 14, and day 23, throughout the study the animals in each group were weighed and blood samples were taken for analysis.
Results
[0144] FIGS. 9 to 12 illustrate the blood glucose level of the animals in each group at the different time periods. As can be seen the blood glucose level decreases over the study period in the group treated with the combination on THCV and rosiglitazone and statistically significant data is obtained for this group at all time points.
[0145] FIG. 13 demonstrates the area under the curve during an oral glucose tolerance test on day 31. These data show that using Bonferroni's Multiple Comparison Test the vehicle versus the combination of THCV and Rosiglitazone was shown to be significant.
Conclusion
[0146] The combination of THCV with anti-diabetic medications produces a significant reduction in blood glucose. This ability of THCV to reduce the blood glucose level in diabetic animals provides further evidence for its use either alone or in combination with other anti-diabetic drugs in the treatment of diabetes.
EXAMPLE 3
A Randomised, Double Blind, Placebo Controlled, Parallel Group, Pilot Study of 1:1 and 20:1 Ratio of Formulated CBD:THCV Plus CBD and THCV Alone in the Treatment of Dyslipdaemia in Subjects with Type 2 Diabetes
[0147] The aim of the pilot study was to evaluate the treatment of dyslipidaemia in subjects with Type 2 diabetes who have failed to achieve satisfactory lipid control with existing treatments.
Materials and Methods
[0148] There were four arms in this study plus a placebo comparator. These were a 1:1 and 20:1 ratio of CBD:THCV, CBD alone and THCV alone. Assessment of the impact of each treatment on different parameters was made. Measurements were taken of high density lipoprotein (HDL) cholesterol, total cholesterol, low density lipoprotein (LDL) cholesterol, HDL/LDL ratio, serum triglycerides, apolipoprotein markers (Apo A & Apo B) and determination of ApoA/Apo B ratio.
[0149] Other measurements including: lipid parameters; glucose control (fasting plasma glucose, glucose tolerance, serum fructosamine, glycosylated haemoglobin A1c (HbA1c) (whole blood)); Insulin sensitivity (insulin resistance); body weight & body mass index (BMI); adipose tissue distribution (total % body fat content, waist circumference, neck circumference, waist-to-hip ratio, visceral adiposity, liver triglyceride content); and appetite 11 point numerical rating scale (0-10 NRS).
[0150] The safety and tolerability of the test compounds compared with placebo were also assessed measurements were recorded for: adverse events (AE); vital signs; Beck Depression Inventory (BDI); Electrocardiogram (ECG).
[0151] Laboratory assessments included; physical examination; markers of vascular function; markers of adipocyte function including leptin and adiponectin; markers of inflammation including cytokines; retinol binding protein (RBP4) concentration; orexin type A (Orexin A) concentration; gut signalling hormone (Gastric Inhibitory Peptide (GIP), Glucagon-like peptide-1 (GLP-1), ghrelin) concentrations; ketone bodies; and endocannabinoid plasma levels.
[0152] The body of data collected for the study was considerably large and as such only representative data are presented within this example.
[0153] The study took place over 15-19 weeks (1-5 week baseline and 13 week treatment period and 1 week follow-up), and was a multicentre, randomised, double blind, placebo controlled, parallel group pilot study which evaluated the test compounds on lipid parameters in subjects with Type 2 diabetes.
[0154] All subjects were receiving either metformin or a sulphonylurea medication yet they had failed to achieve satisfactory lipid and/or glucose control with their existing medication.
[0155] Eligible subjects entered the study at a Screening Visit (Visit 1, Day -35 to -7) and commenced a seven to thirty-five (7-35) day baseline period, before returning for a randomisation visit (Visit 2, Day 1).
[0156] At the discretion of the investigator (based on individual subjects), the Screening Visit (Visit 1) may have been split into two separate visits (Visits 1A and Visit 1B), to allow a 21-day washout period of prohibited medications prior to blood sampling for eligibility.
[0157] Subjects returned for a baseline visit (Visit 2, Day 1, Baseline Visit) where eligible subjects were randomised to treatment groups.
[0158] Further study visits took place at the end of Week 4 of treatment (Visit 3, Day 29), and again at the end of treatment at Week 13 (Visit 5, Day 92). Subjects were asked to fast overnight before Visits 1 (or 1 B), 2 and 5 (minimum 8 hours). A telephone assessment was also performed at Day 57 (Visit 4) and at Week 14 (Visit 6, Day 99) for safety follow-up.
[0159] Diabetic and dyslipidaemic medication usage (where applicable), and NRS appetite visit data will be collected daily during the treatment period using the study diary.
[0160] As this was a pilot study, a formal sample size calculation was not required. Each treatment group consisted of 10 subjects. There was five treatment groups 1:1 and 20:1 ratio of CBD:THCV plus CBD alone, THCV alone and placebo.
[0161] There were five arms to the study which were as follows:
[0000]
Treatment group
Test article
1
5 mg CBD/5 mg THCV twice daily (1:1)
2
100 mg CBD/5 mg THCV twice daily (20:1)
3
100 mg CBD twice daily
4
5 mg THCV twice daily
5
Placebo twice daily
Results
[0162] FIGS. 14 and 15 demonstrate the mean concentration of insulin and glucose in the test subjects treated with THCV blood during an oral glucose tolerance test compared to placebo at the end of the treatment period (Visit 5).
[0163] As can be seen in FIG. 14 , the concentration of insulin in the THCV treated group increases over the first hour and then reduces down to the same level as the placebo after 2 hours.
[0164] FIG. 15 demonstrates that this increase of insulin has the effect of quickly reducing the blood glucose level compared to placebo.
[0165] FIGS. 16 and 17 demonstrate data for all treatment groups using HOMA2 data calculations. This is a computer generated algorithm which provides data for homeostasis model assessments via a calculation of the concentrations of insulin and glucose.
[0166] FIG. 16 shows the mean change from baseline at the end of the study period of the subject's insulin sensitivity. As can be seen the group treated with the THCV had an increased sensitivity to insulin. As type 2 diabetes is associated with reduced insulin secretion, which results in hyperglycaemia these data support the finding in Example 1 that THCV is protective for beta cells.
[0167] FIG. 17 shows the mean change from baseline at the end of the study period of the subjects beta cell function. As can be seen the group treated with THCV had a much increased beta cell function compared to all the other groups. This result was statistically significant and also supports the conclusions from Example 1 that THCV is beta cell protective.
[0168] FIG. 18 demonstrates the change from baseline in mean serum Glucagon-Like Peptide 1 (GLP-1) levels. GLP-1 is a potent anti-hyperglycemic hormone, inducing glucose-dependent stimulation of insulin secretion while suppressing glucagon secretion.
[0169] Such glucose-dependent action is particularly attractive because, when the plasma glucose concentration is in the normal fasting range, GLP-1 no longer stimulates insulin to cause hypoglycemia.
[0170] GLP-1 appears to restore the glucose sensitivity of pancreatic β-cells, it is also known to inhibit pancreatic β-cell apoptosis and stimulate the proliferation and differentiation of insulin-secreting β-cells. In addition, GLP-1 inhibits gastric secretion and motility. This delays and protracts carbohydrate absorption and contributes to a satiating effect.
[0171] GLP-1 agonists are a class of anti-diabetic medications, most of which are in the form of injectable formulations.
[0172] The data shown in FIG. 18 surprisingly demonstrates that an oral dose of THCV is able to act as a GLP-1 agonist. The group treated with THCV showed the highest increase in GLP-1 suggesting that this compound is acting as a GLP-1 agonist.
Conclusion
[0173] The data presented in this Example demonstrates that THCV is a highly useful medicament in for use in the protection of pancreatic islet cells. It also demonstrates that the compound is able to be used effectively as an oral preparation; this alone is of most importance due to many anti-diabetic medications being in the injectable form.
[0174] Furthermore THCV in this study was used in patients who were taking their existing medication of either metformin or sulphonylurea which also supports the conclusion of Example 2 that THCV is effective when used in combination with other anti-diabetic medication.
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The present invention relates to the phytocannabinoid tetrahydrocannabivarin (THCV) for use in the protection of pancreatic islet cells. Preferably the pancreatic islet cells to be protected are beta cells. More preferably the protection of the pancreatic islet cells maintains insulin production at levels which are able to substantially control or improve control of blood glucose levels in a patient.
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BACKGROUND OF THE INVENTION
This invention generally relates to an automatic detergent dispenser apparatus and, more particularly, to an automatic detergent dispenser apparatus for a washing machine and the like, for automatically dispensing a detergent to a washing tub.
A conventional automatic detergent dispenser apparatus for a washing machine and the like is disclosed in Japanese Patent Disclosure No. 54-43827. In this apparatus, cleanser is fed from a hopper into a washing tub through a valve which is manually operated. However, since a feeding amount of a cleanser is determined in accordance with a user's experience, the cleanser cannot always fed in an amount appropriate for the amount of water in the tub.
Therefore, in order to feed a proper amount of cleanser an induction motor may be used as a power source of a cleanser feeding mechanism, and a driving time of the motor is controlled. However, if the driving time of the motor is conditionally set by a timer, the speed at which the motor rotates for the driving time when driven by an AC source voltage of 60 Hz differs from the speed at which the motor rotates when driven by an AC source voltage of 50 Hz. As a result, when the cleanser feeding mechanism having the induction motor is used, a cleanser feeding amount largely varies due to a difference in the source voltage frequencies. To eliminate this problem, the induction motor may be replaced with a DC motor. However, since the speed of rotation of the DC motor largely varies due to a voltage variation, it is difficult to eliminate a variation in the cleanser feeding amount.
As described above, when an induction motor or a DC motor is used as a power source, and the cleanser feeding amount is controlled by changing the driving time of the motor, the amount of the cleanser fed largely varies due to a difference in frequencies of the AC source voltages or due to the voltage variation.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a new and improved automatic detergent dispenser having a synchronous motor, in which the synchronous motor is used as a power source to automatically feed cleanser and a large variation does not occur in the amount of the cleanser fed in spite of a difference in frequencies of AC source voltages.
According to the present invention, there is provided an automatic detergent dispenser apparatus comprising:
cleanser feeding means, having a cleanser housing portion, a cleanser feeding member for feeding a cleanser housed in the cleanser housing portion, and a synchronous motor for driving the cleanser feeding member, thereby to feed an amount of cleanser corresponding to the number of revolutions of the synchronous motor;
cleanser feeding amount-setting means for setting an amount of cleanser to be fed from the cleanser feeding means;
driving means for applying an AC source voltage of an AC power source to the synchronous motor;
counting means for counting the cycles of the AC source voltage from a timing at which the AC source voltage is applied to the synchronous motor;
reference cycle number-setting means for setting a total cycle number of the AC source voltage which corresponds to an amount of cleanser set by the cleanser feeding amount set means; and
motor control means for comparing a count output from the counting means with the total cycle number output from the reference cycle number-setting means and stopping application of the AC source voltage to the synchronous motor when the count and the total cycle number coincide with each other.
In summary, an automatic detergent dispenser apparatus of the present invention is characterized in that a synchronous motor driven by an AC source voltage is used as a power source, a cleanser feeding mechanism feeds an amount of cleanser corresponding to the number of revolutions of the synchronous motor, counting means is provided to count the cycles of the AC source voltage from a timing at which the synchronous motor is driven, and motor control means stops driving of the synchronous motor when the counting means counts the set number of cycles.
In this case, the total number of revolutions of the synchronous motor within the driving time is unconditionally determined in accordance with the total number of the cycles of the AC source voltage within the driving time.
The counting means counts the number of the cycles of the AC source voltage from a timing at which the synchronous motor is driven. When the count reaches a set value, the motor control means stops the driving of the synchronous motor.
Therefore, even if the frequency of the AC source voltage is changed, the total number of revolutions of the synchronous motor remains substantially constant, so that a large variation does not occur in the amount of the cleanser fed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention can be understood from the following description, by reference to the accompanying drawings, in which:
FIGS. 1 to 8 show an embodiment of the present invention in which,
FIG. 1 is an enlarged longitudinal sectional front view of a cleanser feeding mechanism,
FIG. 2 is an enlarged longitudinal sectional side view thereof,
FIG. 3 is a perspective view of an upper portion of a washing machine,
FIG. 4 is a block diagram concerning control of the washing machine,
FIGS. 5A to 5C are views of waveforms of respective portions,
FIGS. 6 and 7 are tables of driving times of a synchronous motor obtained by frequencies of AC source voltages of 60 Hz and 50 Hz, respectively, and
FIG. 8 is a flow chart; and
FIGS. 9 and 10 are a table and a flow chart, respectively, of the total number of cycles supplied to a synchronous motor according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention, or an automatic detergent dispenser apparatus for a washing machine, will be described with reference to FIGS. 1 to 8.
In FIG. 3, reference numeral 1 denotes a casing of a washing machine which can wash clothes and spin-dry them. A known rotary tub (not shown) which is used for both washing and spin-drying clothes is provided in casing 1. Cover 3 for opening/closing a washing port (not shown) is provided on upper cover 2 mounted on an upper surface of casing 1. Reference numeral 4 denotes an operation panel provided on a front portion of upper cover 2. Panel 4 includes a start switch for starting a washing operation, a water level-setting switch for setting a level of water in the rotary tub to "high", "medium", "low", or "lower" level, a cleanser concentration-setting switch for selectively setting a cleanser feeding amount so as to change a cleanser concentration during a wash cycle in accordance with, for example, a degree of dirt of washings, "much", "standard", or "rare". Reference numeral 5 denotes a rear panel provided on a rear portion of upper cover 2. Cleanser feeding mechanism 6 is provided on panel 5.
As is shown in FIGS. 1 and 2, recess 7 is formed in rear panel 5, and mechanism 6 is disposed on recess 7. Mechanism 6 comprises outer case 8 and hopper 9, both made of a transparent plastic material. Hopper 9 is provided with case 8. Transverse cylindrical cleanser feeding portion 10 is formed in the lowermost portion of hopper 9. Transmission shaft 11 is rotatably supported at a left end (in FIG. 1) of portion 10. One end of cleanser feeding member 12 consisting of, e.g., a coil and located in portion 10 is connected to shaft 11. Reference numeral 13 denotes an agitator which is driven upon rotation of member 12 to agitate cleanser 14, and numeral 15 designates a small cover for normally closing outlet 10a of portion 10 and opening outlet 10a when cleanser 14 is to be fed. Synchronous motor 16 for driving member 12 is mounted, at its left end (in FIG. 1), outside recess 7 of rear panel 5. Rotating shaft 16a of motor 16 is projecting into recess 7. Driving gear 17 mounted on shaft 16a meshes with driven gear 18 mounted on transmission shaft 11. Therefore, when an AC source voltage is applied to motor 16, member 12 is rotated by gears 17 and 18, and cleanser 14 is fed from hopper 9 through outlet 10a. In this case, a cleanser feeding amount is determined to correspond to the number of revolutions of member 12 and hence that of motor 16. Water supply unit 20, and water supply port 21 for supplying water from unit 20 to the rotary tub (not shown) are provided in recess 7. Water supply valve 19 is connected to unit 20. A water path extends from unit 20 to port 21 and serves as cleanser receiving portion 22 for receiving a cleanser fed from outlet 10a of cleanser feeding portion 10.
In FIG. 4, reference numeral 23 denotes an operation controller comprising microcomputer 24. Microcomputer 24 receives signals from switches 25 including the water level set switch, the cleanser concentration set switch, the start switch, and the like, water level detector 26 for detecting a water level in the rotary tub (not shown), safety switch 27 for detecting abnormal vibrations of the rotary tub during a spin-drying cycle, and waveform shaping circuit 28. As shown in FIGS. 5A and 5B, circuit 28 supplies a pulse to microcomputer 24 in each cycle of AC source voltage AC. This pulse has a pulse width corresponding to a half cycle from a zero-crossing point of the above cycle. As will be apparent from the following description, microcomputer 24 counts the number of pulses (the cycle number of the AC source voltage) output from circuit 28 from a timing at which motor 16 is driven when a cleanser is to be fed. When the count number reaches a set value, microcomputer 24 stops driving of motor 16. Therefore, microcomputer 24 serves as counting means and motor controlling means. In FIG. 4, reference numeral 29 denotes a clock generator for generating a clock signal for operating microcomputer 24; 30 and 31, drivers, controlled by microcomputer 24, for driving motor 16 and valve 19; 32, a washing machine motor for driving the rotary tub (not shown) and the agitator therein; 33, a water drainage valve; 34, a display for displaying information set by switches 25; and 35, 36, and 37, drivers, controlled by microcomputer 24, for driving motor 32, valve 33, and display 34, respectively. Note that voltage AC is selectively applied to motors 16 and 32 and valves 19 and 33.
Microcomputer 24 has a program for controlling a washing operation and a spin-drying operation, and a program for controlling the feeding of cleanser, performed prior to the washing operation. In order to feed a cleanser in an amount corresponding to a water level and a cleanser concentration set by the switches, microcomputer 24 stores the driving time of motor 16 in units of frequencies of the AC source voltage in a form of a table. FIGS. 6 and 7 show the driving time of motor 16 for the respective frequencies.
The cleanser feeding-operation performed prior to start of the washing operation in the above arrangement will be described below with reference to the flow chart shown in FIG. 8.
First, a desired water level corresponding to a weight of the items to be washed is set by operating the water levelsetting switch. Then, a desired cleanser concentration is set by operating the cleanser concentration-setting switch. Further, the start switch is operated. Then, the driving time of motor 16 is automatically set as follows.
That is, microcomputer 24 counts the number of pulses of the clock signal supplied from generator 29 within a time interval corresponding to one pulse supplied from circuit 28 as shown in FIG. 5C, i.e., a time interval corresponding to a half cycle of the AC source voltage, and determines a frequency of the AC source voltage in accordance with the count number. Then, in accordance with the frequency of the AC source voltage thus determined and the water level and the cleanser concentration set as described above, microcomputer 24 reads out a predetermined time from data stored in a form of a table as shown in FIGS. 6 and 7, and sets the readout time as the driving time of motor 16. Assume that the frequency of the AC source voltage is 60 Hz, the set water level is "medium", and the set cleanser concentration is "standard". In this case, the driving time of motor 16 is set to 54 seconds in accordance with time data shown in FIG. 6.
When the driving time of motor 16 is set as described above, water supply valve 19 is driven to start water supplying, and motor 16 is driven to start cleanser feeding. At the same time, microcomputer 24 starts counting of the pulses input thereto from circuit 28, thereby calculating a time elapsed from the start of driving of motor 16 in accordance with the counted number of the pulses. That is, in this embodiment, the number of pulses has a one-to-one correspondence with the cycle number of the AC source voltage. Therefore, when the frequency of the AC source voltage is 60 Hz and the pulse count number is 120, the elapsed time is calculated to be 2 seconds. Motor 16 is continuously driven until the elapsed driving time of motor 16, thus calculated, coincides with the set driving time. When the elapsed driving time coincides with the set driving time, or the count number of pulses from circuit 28 reaches 3,240 when the set time is 54 seconds, motor 16 is stopped.
When cleanser feeding and water supplying are started, cleanser feeding member 12 of FIG. 1 is rotated by motor 16 so that a cleanser stored in hopper 9 falls down from outlet 10a of cleanser feed portion 10 to cleanser receiving portion 22. At the same time, water is supplied to the rotary tub (not shown) from unit 20 through valve 19, port 21 and portion 22. Therefore, the cleanser fed in portion 22 is carried down by water into the rotary tub.
After water supplying is started, water level detection signals are normally supplied from detector 26 to microcomputer 24. In step S1 of the flow chart shown in FIG. 8, microcomputer 24 determines whether the water level in the rotary tub, detected by the water level detection signal, has reached a water level (to be referred to as a first target level hereinafter) lower than the set water level by a predetermined water level. When the water level in the rotary tub has reached the first target water level upon continuous supply of water, microcomputer 24 determines "YES" in step S1, and the flow advances to step S2. In step S2, microcomputer 24 determines whether cleanser feeding is finished, i.e., the set driving time of motor 16 has elapsed. In this case, microcomputer 24 determines whether the set driving time has elapsed by determining whether the count value of the cycle number of the AC source voltage from start of driving reaches "3,240" if the set driving time of motor 16 is 54 seconds. If cleanser feeding is finished when the flow advances to step S2, microcomputer 24 determines "YES" in step S2, and the flow directly advances to step S3. In step S3, microcomputer 24 determines whether the water level in the rotary tub reaches a final target water level. If the water level has not reached the final target water level, microcomputer 24 determines "NO" in step S3, and water is continuously supplied until the final target water level is reached. When the water level in the rotary tub has reached the final target water level, microcomputer 24 determines "YES" in step S3 and stops driving of valve 19. As a result, water supplying is stopped, and the wash operation is started.
Water remaining in a bath tub is sometimes supplied into the rotary tub prior to washing. If water supplying is started by operating the start switch while water is stored beforehand in the rotary tub as described above, the water level in the rotary tub sometimes reaches the first target water level before cleanser feeding is finished, i.e., the set driving time of motor 16 has elapsed. In this case, microcomputer 24 determines "NO" in step S2. Then, microcomputer 24 controls driving of valve 19, e.g., drives valve 19 for 2 seconds and stops driving thereof for 10 seconds. Such intermittent water supplying is continuously performed until the cleanser feeding is finished. The cleanser fed to cleanser receiving portion 22 during this intermittent supply of water is supplied along with the water into the rotary tub. Hence, the cleanser does not remain in portion 22. When cleanser feeding is finished, microcomputer 24 determines "YES" in step S2 and finishes intermittent water supplying. Then, the flow advances to step S3. In step S3, valve 19 is continuously driven until the final target water level is reached. When the final target water level is reached, valve 19 is stopped, and the washing operation is started.
As described above, according to the above embodiment, in the cleanser feeding mechanism wherein the cleanser feeding amount is determined in accordance with the number of revolutions of cleanser feeding member 12, the total number of revolutions of synchronous motor 16 as a drive source of the mechanism within a driving time is unconditionally determined in accordance with the total cycle number of the AC source voltage counted within the driving time. In this embodiment, the driving time of motor 16 is controlled by counting the number of cycles of the AC source voltage from start of driving. That is, according to FIGS. 6 and 7, if the set water level is "medium" and the set amount of cleanser is "standard", the driving time is 54 seconds for 60 Hz and is 65 seconds for 50 Hz. In this case, the cycle count number of the AC source voltage for controlling the driving time is "3,240" for 60 Hz and is "3,250" for 50 Hz. Thus, a difference between the cycle numbers is only "10". That is, the total number of revolutions of motor 16 rarely varies regardless of whether the frequency of the AC source voltage is 60 Hz or 50 Hz. Therefore, the cleanser feeding amount does not largely vary, despite a difference in the frequencies of the AC source voltages, and substantially the same amount of cleanser can be fed under the same conditions regardless of the frequency.
Note that in the above embodiment, microcomputer 24 stores the driving time of motor 16 in units of frequencies of the AC source voltage in the form of a table. However, as shown in FIG. 9, microcomputer 24 may store the total cycle number of the AC source voltage applied to motor 16 in the form of a table regardless of its frequency. In this case, as shown in the flow chart of FIG. 10, motor 16 is stopped when the number of pulses output from waveform shaping circuit 28 which is counted from the starting of driving of motor 16 has reached the set cycle number. According to this embodiment, since the number of cycles applied to the synchronous motor remains the same regardless of the frequency of the AC source voltage, i.e., whether the frequency is 60 Hz or 50 Hz, the cleanser feeding amount remains the same.
The present invention is not limited to the embodiment described above with reference to the accompanying drawings. For example, the cleanser feeding member may be a screw or the like as long as a cleanser feeding amount is determined by the number of revolutions of the synchronous motor. Moreover, the present invention can be applied to not only a washing machine but also to any system using a cleanser such as a dish washer. Thus, the present invention can be variously modified and carried out without departing from the spirit and scope of the invention.
As is apparent from the above description, according to the automatic detergent dispenser apparatus for a washing machine and the like, a synchronous motor driven by an AC source voltage is used as a power source, a cleanser feeding mechanism is provided to feed a cleanser in an amount corresponding to the number of revolutions of the synchronous motor, counting means is provided to count the number of cycles of the AC source voltage from a timing at which the synchronous motor is driven, a motor control means is provided to stop driving of the synchronous motor when the counting means counts a set cycle number. Therefore, even if the frequency of the AC source voltage is changed, the number of cycles of the AC source voltage applied to the synchronous motor is controlled to be substantially or completely the same. As a result, a total number of revolutions of the synchronous motor becomes substantially or completely the same regardless of the frequency of the AC source voltage, so that a large variation in a cleanser feeding amount can be effectively prevented.
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A cleanser feeding mechanism has a cleanser housing portion, a cleanser feeding member for feeding a cleanser housed in the cleanser housing portion, and a synchronous motor for applying a drive force to the cleanser feeding member, and feeds and amount of cleanser corresponding to the number of revolutions of the synchronous motor. A cleanser feeding amount-setting unit sets an amount of cleanser to be fed from the cleanser feeding mechanism. A driving unit applies an AC source voltage of an AC power source to the synchronous motor. A counter counts the number of cycles of the AC source voltage from a timing at which the AC source voltage is applied to the synchronous motor. A reference cycle number-setting unit sets a total cycle number of the AC source voltage which corresponds to a cleanser amount set by the cleanser feeding amount-setting unit. A motor controller compares a count output from the counter with a total cycle number from the reference cycle number-setting unit and stops application of the AC source voltage to the synchronous motor when the count output and the total cycle number coincide with each other.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 09/975,743, filed Oct. 11, 2001, now U.S. Pat. No. 6,623,519, which is a division of application Ser. No. 09/321,496, filed May 27, 1999, now U.S. Pat. No. 6,358,276, which claims the benefit of U.S. Provisional Application No. 60/105,768, filed Sep. 30, 1998. This application expressly incorporates by reference the entirety of each of the above-mentioned applications as if fully set forth herein.
BACKGROUND OF THE INVENTION
The present invention relates generally to endoluminal devices, and more particularly to stents.
Stents and similar endoluminal devices have been used to expand a constricted vessel to maintain an open passageway through the vessel in many medical situations, for example, following angioplasty of a coronary artery. In these situations, stents are useful to prevent restenosis of the dilated vessel through proliferation of vascular tissues. Stents can also be used to reinforce collapsing structures in the respiratory system, the reproductive system, biliary ducts or any tubular body lumens. Whereas in vascular applications fatty deposits or “plaque” frequently cause the stenosis, in many other body lumens the narrowing or closing may be caused by malignant tissue.
Fluids have traditionally been used to pressurize the angioplasty balloons used to open restricted vessels. The balloons may have a variety of shapes including a coiled form. In such a device fluid is injected into the balloon to inflate the device and maintain turgidity. Shturman (U.S. Pat. No. 5,181,911) discloses a perfusion balloon catheter wound into a helically coiled shape with one end attached to a fitting and the other to a syringe for inflating the balloon with fluid. When the balloon is inflated, its coiled form allows blood flow thorough the open center of the structure. At the same time it is possible to actually have fluid flow within the balloon structure so that the syringe can deliver fluid into the balloon, fluid can flow through the balloon, and fluid can then exit through a second lumen in a catheter attached to the syringe.
Coiled stents that are connected to a catheter apparatus, as in Wang et al. (U.S. Pat. No. 5,795,318), are used for temporary insertion into a patient. Wang et al. discloses a coiled stent of shape-memory thermoplastic tube that can be converted from a relatively narrow diameter to a larger coiled form by heating. The narrow diameter coil is mounted at the end of a catheter over a balloon and in a preferred embodiment a resistive heating element runs down the length of the thermoplastic element. An electric current is applied to heat the element thereby softening it while the balloon is expanded to enlarge the diameter of the coil. Upon cooling the enlarged coil hardens and the balloon is withdrawn. After the temporary stent has performed its duty, it is again heated and removed while in the softened state. In one embodiment the thermoplastic tube is supplied with an additional lumen so that liquid drugs can flow into the stent and delivered through apertures or semi-permeable regions.
The attempt to kill or prevent proliferation cells is a common theme in clinical practice. This is generally true in vascular and non-vascular lumens. It is known that ionizing radiation can prevent restenosis and malignant growth. Although the effect of temperature extremes, e.g., cryogenic (cold) or hot temperatures, on cellular activity is not as well researched, it may provide a safer approach to control of tissue proliferation. Among the drawbacks of the prior art coiled balloons is that the balloon material is relatively weak so that expansion and contraction cause the balloon to fail. Failure of a balloon containing radioactive or cryogenic fluids could be catastrophic. It would be desirable to provide a catheter based, minimally invasive device for stenting support that could deliver hot or cryogenic or radioactive fluids or drugs and that would be sturdy and could remain in the body for extended periods of time, detached from the insertion device.
BRIEF SUMMARY OF THE INVENTION
In its simplest embodiment the present invention is an endoluminal coil stent comprising a hollow tube formed into a series of loops or other known stent shapes which initially has a low profile and diameter. This structure can be delivered into a patient's vascular system and expanded to full size. The present invention to provides a stent that is hollow allowing the passage of fluid. The stent has either one or a plurality of passageways for fluid flow. The stent is attached to a catheter via a special fitting so that when engaged with the catheter, fluid flows freely from the catheter to the stent with a possible return circuit through the catheter. When disengaged, the fitting prevents leakage from the stent permitting the stent to remain in place in a patient's vasculature.
This invention provides a way of treating vascular areas affected with malignant growths or experiencing restenosis from smooth muscle cell proliferation, etc. The stent is inserted in a small diameter configuration and after being enlarged to a larger diameter, acts as a support device for the areas of restenosis or malignant growth. In addition, the stent can treat these affected areas in a unique way by flowing radioactive, heated or cryogenic fluids through the stent.
The present invention also provides a way of delivering drugs to an affected site. A stent to accomplish this purpose can be composed of several different materials. For example, the stent can formed from a metal or other material with small pores machined or otherwise formed (e.g., with a laser). When such a stent is filed with a drug, that drug slowly disperses through the pores. Alternatively, an entire metal tube or portions of the tube could be formed e.g., from sintered metal powder thereby forming a porous structure for drug delivery. Another embodiment would alternate a metal tube (for structural stability) with dispensing segments inserted at various intervals. The segments would be perforated to allow seepage of the drug or would be otherwise formed from a porous material. Another embodiment employs an expanded polytetrafluoroethylene (PTFE) tube around a support wire or metal tube in the form of a coiled stent so that a hollow passageway is created between the metal and the PTFE. A drug is flowed into this space and slowly dispensed through the porous PTFE.
One embodiment of the hollow stent of the present invention comprises a shape memory metal such as nitinol. Shape memory metals are a group of metallic compositions that that have the ability to return to a defined shape or size when subjected to certain thermal or stress conditions. Shape memory metals are generally capable of being deformed at a relatively low temperature and, upon exposure to a relatively higher temperature, return to the defined shape or size they held prior to the deformation. This enables the stent to be inserted into the body in a deformed, smaller state so that it assumes its “remembered” larger shape once it is exposed to a higher temperature (i.e. body temperature or heated fluid) in vivo.
Special fittings are incorporated at the ends of the hollow stent. These fittings facilitate the injection and removal of fluid and also allow the stent to be detached from the insertion device to be left in place in a patient. The hollow stent has an inlet and an outlet so that a complete fluid path can be created, and fluid can be continually circulated through the stent. In the simplest configuration the inlet and outlet are at opposite ends of the stent. However, if the stent is equipped with a plurality of lumens, two lumens can be connected at a distal end of the structure so that the outlet and inlet are both together at one end. Other arrangements can be readily envisioned by one of ordinary skill in the art.
The stent is inserted into the body while connected to a catheter in a small, deformed state. Once inside the patient's body the stent is advanced to a desired position and expanded to its larger full size. If the stent is composed of shape memory metal, for example, the stent expands from its small-deformed state to its remembered larger state due to the higher body temperature or due to the passage of “hot” fluid through the stent. Subsequently “treatment” fluid (e.g., heated, cryogenic or radioactive) is pumped through the catheter to the stent where it is circulated throughout the stent, treating the adjacent vascular walls. The catheter can either be left in place for a certain period of time or removed, leaving the fluid inside the stent. This would particularly be the case with radioactive fluid or with a porous drug delivery stent.
The stent can be removed by reattaching the catheter allowing one to chill and shrink the stent (in the case of a memory alloy). Alternatively, the device can readily be used in its tethered form to remove memory alloy stents of the present invention or of prior art design. For this purpose a device of the present invention is inserted into the vasculature to rest within the stent to be removed. Warm fluid is then circulated causing the stent to expand into contact with the memory alloy stent that is already in position. At this point cryogenic (e.g., low temperature) fluid is circulated causing the attached stent and the contacted stent to shrink so that the combination can be readily withdrawn.
These and other embodiments, features and advantages of the present invention will become more apparent to those skilled in the art when taken with reference to the following more detailed description of the invention in conjunction with the accompanying drawings that are first briefly described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a hollow coiled stent.
FIG. 2 is a perspective view of a valve assembly to be used with FIG. 1 .
FIG. 3 is a sectional view of the hollow stent tube of FIG. 2 .
FIG. 4 is a representation of the stent of FIG. 1 in the position for treatment.
FIG. 5 is a sectional view of a second embodiment of a hollow coiled stent.
FIG. 6 is a perspective view of a second embodiment of a hollow coiled stent.
FIG. 7 is a perspective view of a third embodiment of a hollow coiled stent.
FIG. 8 is a perspective view of a valve assembly to be used with FIG. 6 .
FIG. 9 is a perspective view of a fourth embodiment of a hollow coiled stent.
FIG. 10 is a sectional view of the hollow stent tube of FIG. 8 .
FIGS. 11 ( 11 a , 11 b , and 11 c ) is an illustration of the method detailed in FIG. 12 .
FIG. 12 is a flow diagram explaining use a stent of the present invention to retrieve a shape memory stent already in place.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict selected preferred embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
Referring now to the drawings, in which like reference numbers represent similar or identical structures throughout the drawings, FIG. 1 depicts a preferred embodiment of this invention. Pictured in FIG. 1 is a medical apparatus 10 comprising an endoluminal stent 20 attached to a delivery catheter 30 by means of a valve assembly 40 . In this representation endoluminal stent 20 is generally coiled in shape leaving a tubular space down the center of its length. Obviously, the principle of a hollow stent can be applied to stents of a zigzag or other construction other than simply coiled. The tubing 22 of the stent 20 is preferably composed of a metal material that can be crimped onto a balloon catheter (not shown) for insertion into a body. Once positioned inside of the body at the desired location, the balloon can be inflated, bringing the stent from a compact small size to its enlarged full size thus opening a pathway for blood flow.
Inside the tubing 22 of stent 20 , two fluid pathways exist. These pathways can be seen in the cross sectional view of FIG. 3 . Pathways 26 and 28 have opposite flowing fluid streams and connect at the distal end 24 of stent 20 . By allowing for opposite streams, radioactive, heated or cryogenic liquids can continuously flow through stent 20 for the purpose of killing or preventing proliferation of cells. By “heated” or “hot” is meant temperatures above body temperature. By “cryogenic” or “cold” is meant temperatures below body temperature. The stent 20 can either remain connected to a delivery catheter 30 for temporary insertion, or be detached for a more permanent insertion. In either case, fluid flow can be circulated throughout stent 20 prior to disconnection. In the simplest design, fluid passageways connected to the stent 20 are lumens of the delivery catheter so that when the catheter is withdrawn, fluid flow must cease.
It is also possible to provide separate flexible tubes that are threaded through the catheter so that the delivery catheter can be withdrawn leaving the relatively smaller fluid delivery tubes (not shown) behind. Preventing leakage of the fluid from the stent 20 after the catheter 30 is disconnected is accomplished through a valve mechanism contained in the catheter 30 , or the stent 20 and/or both. In the example illustrated in FIG. 2 rubber or elastomer diaphragms 25 are penetrated by small hollow needles 48 in the valve assembly 40 . In addition, the valve 40 may comprise a simple back flow preventer. Thus, when pressure is applied from incoming fluid to the valve assembly 40 , a ball 45 which sits in a ball seat 44 is forced back against a spring 46 and the valve 40 opens for the incoming fluid pathway 28 . A similar arrangement allows pressure to open the outgoing fluid pathway 26 . A check ball valve is shown only as an example. Flap valves or any of a number of other back flow valve designs well known in the art can be employed. Complex systems in which a bayonet-type attachment automatically opens a valve are also possible.
The catheter 30 comprises a catheter shaft 32 , which further contains two fluid pathways 34 and 36 as seen in FIG. 2 . At the distal end of catheter 30 , the valve assembly 40 has small hollow needles 48 that are designed to puncture elastomer diaphragms 25 . The catheter 30 is slightly larger in diameter than the stent member 20 so that the catheter tubing wall 32 forms a friction fit over the stent wall 22 . This creates a seal between the catheter 30 , and the stent 20 for fluid delivery and removal. Upon detaching the catheter 30 leakage from the stent 20 is prevented due to the self-healing properties of the diaphragms 25 . Obviously, the back flow preventer 40 could be on the stent 20 and the diaphragms could be on the catheter 30 .
As discussed above, stent 20 is inserted into the body to the desired site through the use of a catheter insertion device well known in the art. FIG. 4 depicts stent 20 in its enlarged form after it has been inserted into the body at the affected location and expanded. Other means of stent expansion other than a balloon catheter are possible. If the stent 20 is formed from shape memory metal, such as Nitinol, the heat of the body can cause the stent 20 to assume a larger, remembered form. Alternatively, heated fluid can be circulated through the stent to cause it to recover its remembered form. A self-expanding stent made of a spring-type alloy can also be employed. In that case the delivery catheter would be equipped with means (e.g., an outer sheath) to keep the stent compressed until it was at the desired location.
By increasing the diameter of stent 20 at an affected location, the passageway is enlarged to permit increased blood flow. At the same time, fluids can pass through the interior of tubes 22 of the hollow stent 20 to treat the vascular wall. The walls of the vasculature can be treated by running either a radioactive, cryogenic or heated fluid through the stent 20 or by delivering a drug through a stent equipped for drug diffusion (e.g., through holes or a porous region).
FIG. 5 depicts a second embodiment of the invention. In this embodiment, the hollow stent 60 has only one fluid pathway 66 , an inlet without an outlet, and is used to deliver drugs to affected areas. Once the stent 60 is inserted into place and is in its enlarged configuration, drugs are delivered through the catheter to the stent 60 . Stent 60 can be constructed in various ways to facilitate the delivery of drugs. In one case, as shown in FIG. 6 , the stent 60 is constructed with regions or segments that have pores 64 to allow drug seepage from the tubing 62 . Alternatively, continuously porous metal, porous plastic, or a combination of metal and plastic can be used. The perforations 64 or slits in the stent to facilitate drug delivery must be of sufficiently small size to allow the passage of the drug through the entire length of the stent so that all areas can be treated. It will be apparent that pore size can control the rate at which the drug is dispensed. It is possible to cover the pores 64 with semi-permeable membrane to further control and restrict drug outflow. A semi-permeable membrane with inclusion of an osmotic agent with the drug will result in water uptake and more rapid and controlled pressurized delivery of the drug.
A third embodiment of the invention, FIG. 7 , has a hollow stent 70 containing a single fluid pathway. The tubing 72 can be made of any of the materials discussed above, but in this embodiment, the stent 70 has an inlet path 78 that carries the fluid to the distal end 74 of stent 70 where it then runs through the coils. In this embodiment, a valve 80 connects the stent 70 to catheter 30 . FIG. 8 a cross-sectional view of valve 80 . The pressure from the liquid sent through the catheter causes the gate 82 of valve 80 to open to allow the fluid into the inlet path 78 . The pressure that forces the opening of gate 82 causes the simultaneous opening of gate 84 , allowing the fluid that is circulated through the stent 70 to exit through pathway 36 of catheter 30 . The fluid entering and exiting through catheter 30 must also go through a check ball valve assembly similar to the one shown in FIG. 2 . Again, flaps or other “one way” valve mechanisms can be applied. After all incoming fluid has been delivered to the stent 70 , the absence of pressure causes gate 82 and gate 84 to close, thereby closing valve 80 . This design can be used with any of the fluids mentioned above. The stent 70 can be used to circulate radioactive or cryogenic fluids for treatment of the vascular walls and can also be perforated for the delivery of drugs.
In a fourth embodiment, a hollow coiled stent 90 is formed from polytetrafluoroethylene (PTFE) 92 . In FIG. 9 , a perspective view of this embodiment can be seen. The stent 90 consists of a support wire 94 over which PTFE 92 is fitted. The pliable structure resulting is then formed into a coiled stent. The PTFE 92 is fitted around the wire 94 so that there is sufficient room to allow the passage of fluid. FIG. 10 shows a cross-sectional view of stent 90 , illustrating the pathway 96 created around the support wire 94 to allow the passage of fluid. In this embodiment, stretched expanded PTFE can be used to create a porous stent to facilitate the delivery of drugs. The wire 94 can also be hollow (passageway 95 ) so that the stent 90 can simultaneously deliver drugs and radioactive fluid or temperature regulating fluid.
A fifth embodiment of the invention is illustrated in FIG. 11 and described in a flow diagram shown in FIG. 12 . This embodiment is a method for recapturing an existing shape memory metal stent already in the body. With reference to both FIGS. 11 and 12 , a shape memory metal stent A is inserted into the body in its small, deformed state through the use of an insertion device well known in the art in step 112 . The inserted stent A in its deformed state is placed into the center of a memory alloy stent B that is already in an enlarged support position in the body in step 114 . The deformed stent A is then enlarged so that it comes in contact with stent B. This can be accomplished in one of two ways. Either the stent A may enlarge due to the higher in vivo body temperature in step 115 , or a hot liquid may be pumped through stent A to cause it to expand in step 116 . Once expanded and in contact with stent B, cryogenic liquid may be pumped through stent A so that both stent A and stent B are chilled and either shrink down to their deformed states or become sufficiently relaxed to allow ready removal in step 118 . Once in a small, deformed or relaxed state, stents A and B are easily removed from the body in step 119 by withdrawing the catheter attached to stent A. FIG. 11 a illustrates stent A in its reduced state being inserted into stent A. FIG. 11 b shows an enlarged version of stent A contacting stent B. Thereafter, a temperature change caused, for example, by fluid circulating through stent A will shrink both stents and enable their removal ( FIG. 11 c ).
Having thus described a preferred embodiment of a hollow endoluminal stent, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, a hollow stent with a coiled, tubular shape has been illustrated, however, many other possibilities exist for the shape and size of the hollow stent. In addition, the passageways are illustrated as round but could take on a variety of other shapes. The described embodiments are to be considered illustrative rather than restrictive. The invention is further defined by the following claims.
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An endoluminal stent contains a hollow passageway for the circulation of heated and/or cryogenic fluids to recapture a previously implanted shape memory stent. The hollow passageway stent can have one or a plurality of passageways and is configured in a tubular shape with numerous coils, providing an empty tubular lumen through the center of the stent to allow blood flow. The stent is connected to a removable catheter that conducts fluid to the stent. Fluid flow may be regulated by valves incorporated in either the stent and/or the catheter.
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BACKGROUND OF THE INVENTION
This invention relates to toys and, more particularly, to a toy which produces and shapes masses of small bubbles to simulate objects.
There have been many toys suggested by the prior art which contain mechanisms for producing bubbles. For example, U.S. Pat. No. 2,675,644, H. Senior et al, issued Apr. 20, 1954; U.S. Pat. No. 2,839,868, R. A. Lathrop, issued June 24, 1958; U.S. Pat. No. 2,842,894, H. W. Walden, issued July 15, 1958; and U.S. Pat. No. 2,853,829, N. A. Greene, issued Sept. 30, 1958 all disclose various toys which contain a mechanism for blowing bubbles. In each of these toys, however, the object of the toy is to blow one or more bubbles as an end in and of itself. These toys take different forms, however; and often represent a figure (such as a person) which appears to be blowing the bubbles. Another toy which produces bubbles is that disclosed in U.S. Pat. No. 3,590,515, issued July 6, 1971, to the assignee of the present application; this toy is a doll which produces a shampoolike foam in its hair when its sides are squeezed so that the doll appears to be shampooing its hair.
None of the prior art discloses, however, a toy which has a mechanism for producing masses of small bubbles and utilizing those bubbles to produce a recognizable shape.
It is an object of the present invention to provide a new and unique toy which produces masses of small bubbles and to shape those bubbles to provide a recognizable form.
It is another object of this invention to provide an improved mechanism for generating bubbles.
It is another object of this invention to provide a new and improved toy capable of generating and shaping bubbles in a number of recognizable forms.
SUMMARY OF THE INVENTION
The foregoing and other objects of the invention are accomplished by a toy which utilizes a unique mechanism for producing bubbles at an outlet. The toy has a number of different interchangeable shaping devices each of which may be placed over the outlet of the bubble producing mechanism. Each of the shaping devices is molded in a particular form so that it provides an incomplete shape of an object such as a lion or a clown which is recognizable to a child. The bubbles are directed by the shaping devices to complete the form of the recongizable shape.
Other objects, features, and advantages of the invention will become apparent from a reading of the specification when taken in conjunction with the drawings in which like reference numerals refer to like elements in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a toy constructed in accordance with the invention and showing in FIGS. 1A and 1B various embodiments of shapers to be used with the toy of the invention;
FIG. 2 is a front view in cross-section of the internal mechanism of the toy shown in FIG. 1;
FIG. 3 is a side view, partially in cross-section, of the toy shown in FIG. 1; and
FIG. 4 is an exploded perspective view of the toy shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, more particularly, to FIG. 1, there is shown a toy 10 constructed in accordance with the invention. The toy 10 comprises a bubble generating mechanism 12 of generally cylindrical form mounted upon a pedestal 14 supported by a base 16. The bubble generating mechanism 12 supports a shaper 18 which in a preferred embodiment is molded with an essentially hollow interior and has an exterior form depicting a particular, well recognizable object. In FIG. 1, the object is a lion. The form is incomplete, however; and the shaper 18 has a number of conduits from its interior to its exterior to provide exits for bubbles generated by the mechanism 12. The conduits are arranged in a pattern so that the bubbles escaping the shaper 18 will take a shape to complete the form of the object incompletely depicted by the shaper 18. In the particular embodiment shown in FIG. 1, the form of a lion is completed by bubbles 20 exiting from conduits (not shown in FIG. 1) to form a mane.
The bubble generating mechanism 12 rotatably mounts a handle 22 on its side which is cranked to activate the mechanism 12 to produce the bubbles which form the particular shape desired. The shaper 18 may be removed from the mechanism 12, as will be described hereinafter, and may be replaced by a shaper having a different recognizable but incomplete form and which provides conduits to shape bubbles to complete its particular form.
As shown in FIGS. 1A and 1B, various embodiments of the invention utilize shapers 21 and 23 constructed in the form of a clown which has conduits 19 formed to shape bubbles to complete its hairdo, and in the form of an elephant with conduits 17 formed to shape bubbles to define ears and a trunk. The form of the soap bubble masses for shapers 21 and 23 are shown in dotted lines in FIGS. 1A and 1B. Obviously other forms of shapers might be provided by those skilled in the art without departing from the teaching of the invention.
Referring now to FIGS. 2, 3, and 4, there are shown the details of the toy 10 shown in FIG. 1. As shown in FIG. 1, the toy 10 includes the bubble generating mechanism 12 which is supported upon pedestal 14 and base 16. In the preferred embodiment shown in FIGS. 2-5, the bubble generating mechanism 12, the pedestal 14, and the base 16 are molded from a plastic material such as styrene so that they have a unitary outer housing. For example, as shown in FIG. 2, an outer housing 24 of the mechanism 12 and the outer housings of the base 16 and the pedestal 14 are all molded together in front and rear sections which may be fastened together in a well known manner such as by adhesive bonding. The outer housing 24 of the mechanism 12 has an aperture 26 which rotatably mounts an inner end 28 of the handle 22. The end 28 of the handle 22 terminates in an elliptically shaped cam 30. When the handle 22 is rotated within the aperture 26, the cam 30 provides a reciprocating motion to an end 32 of a shaft 34 against which it bears. The shaft 34 is rotatably mounted to the housing 24 upon an axle 36. The reciprocation of the end 32 of the shaft 34 forces a second end 38 of the shaft 34 to reciprocate against the lower surface of an outer cup 40 mounted within the housing 24. The cup 40 may be constructed of a moldable plastic material such as ethylene vinyl acetate. The upper walls of the cup 40 thin and flare outwardly, then turn upward and outward again, at the upper edge where they are supported by the housing 24. This shape provides a spring which flexes so that the cup 40 may be pushed upward along its axis by the end 38; and when pressure is removed as the end 38 withdraws during reciprocation, the cup 40 springs downwardly along its axis.
The cup 40 has a check valve 42 mounted in its lower surface (which may be any of a number of well known types) positioned to allow the equalization of pressure between the interior of the cup 40 and the exterior thereof when the cup 40 travels in the downward direction as shown in FIG. 2.
Also supported within the housing 24 is an inner cup 44 which may be constructed of a material such as styrene. The cup 44 lacks the flexing properties of the cup 40 and, consequently, remains in position supported by the housing 24 as the cup 40 is moved up and down. The cup 44 has a flange 46 extending outwardly from its upper body which is hermetically fastened, by means well known in the art such as an adhesive bond, to an upper ridge 48 projecting from the cup 40. The lower surface of the ridge 48 is hermetically fixed to an inwardly extending flange 49 projecting from the housing 24. Consequently, there is formed an air pocket within the space between the exterior of the cup 44 and the interior of the cup 40. The flange 46 of cup 44 has positioned on its upper surface a check valve 50 of a type well known in the art arranged to allow the relief of pressure built up between the cups 40 and 44.
Positioned over and sealed to the housing 24 is an upper housing 52 of the mechanism 12 having a downwardly extending cylindrical flange 54. The upper housing 52 is hermetically sealed to the housing 24 and to the flange 46 to provide a chamber 56 into which the check valve 50 exhausts. The chamber 56 exhausts through an aperture 58 in the flange 54 so that an increase in pressure in the chamber 56 will cause an increase in pressure in the interior of the cup 44.
The upper housing 52 has a circular aperture therein through which extends a stopper 60 of a soft rubber-like material. The stopper 60 is removable, forms a seal with the housing 52, and supports a tube 62 which is coaxially aligned with it and depends therefrom. The tube 62 has an upper flange 64 which provides a seal with the stopper 60. The upper flange 64 supports a retainer 66 which is affixed to the flange 64 by means such as sonic welding. Between the flange 64 and the retainer 66 is positioned a screen 68 of a material such as stainless steel having a mesh of from one hundred to one hundred fifty. Alternately, the screen 68 may comprise a cloth material having like characteristics.
The tube 62 has a conduit running axially therethrough which opens at an aperture 70 into the cup 44. The tube 60 also has an aperture 72 which is so configured as to provide an exit for gases both through the flange 64 and into the interior of the tube 62. In use, a liquid soap 67 is placed within the cup 44 by removing the stopper 58. The sizes of the openings of the apertures 70 and 72 are so adjusted that, with a material having a viscosity such as that of the usual liquid soap commercially available, an increase in pressure within the chamber 56 increases the pressure on the upper surface 74 of the liquid soap 67 within the cup 44, forcing the soap 67 through the aperture 70 and up the tube 62. As the soap 67 continues up the tube 62, it receives air through the aperture 72 causing the generation of bubbles within the retainer 66 as the soap 67 passes out of the tube 62 and through the screen 68. This generation of bubbles is enhanced by the air forced through the flange 64.
The increase in pressure on the surface 74 is caused as follows. The handle 22 is rotated causing the cam 30 to bear against the end 32 of shaft 34 rocking shaft 34 back and forth upon its axle 36. The rocking of shaft 34 causes the end 38 to move up and down along the axis of cup 40 forcing the cup 40 to approach and then withdraw from the cup 44. As the cup 40 approaches the cup 44, the check valve 42 is closed by the increase in pressure. This action further increases the pressure between the cups 40 and 44 and ultimately opens the check valve 50 causing an increase in pressure within the chamber 56. This pressure increase is transferred via the aperture 58 into the interior of the cup 44 thereby increasing the pressure on the upper surface 74 of the soap 67. This increase in pressure, as noted above, forces the fluid through the aperture 70 and upward through the tube 62 and forces air through the apertures 72 and 63 to generate bubbles in the fluid as it passes up the tube 62 and through the screen 68 which assists in breaking the fluid into bubbles. As may be seen, the retainer 66 has apertures therein so that the bubbles are forced into the interior of the shaper 18 and ultimately out of the apertures 76 therein. As may be seen in FIG. 2, the apertures 76 are placed so that the bubbles which issue therefrom form in the shape of a mane for the lion shaper 18 shown in the FIG. 2. Consequently, the bubbles exiting from the apertures 76 complete the form of the shaper 18 as the handle 22 is cranked.
As may be seen in FIG. 2, the shaper 18 is positioned over the upper end of the stopper 60 and may be easily removed therefrom simply by an upward pull on the shaper 18. This allows different shapers to be positioned upon the stopper 60 thereby enhancing the use of the toy 10.
In contrast to the shaper 18 shown in FIG. 1, the shaper 21 and 23 shown in FIGS. 1A and 1B have apertures 19 and 17 positioned in such a manner as to produce, respectively, a hairdo for a clown and large ears and a spout for an elephant when the handle 22 is rotated.
In order to produce the arrangement by which the liquid soap moves from the interior of the cup 44 through the apertures 70 and 72 of the tube 62, the aperture 70 is formed with a diameter of approximately 0.040 inches, and the aperture 72 has a rectangular cross section opening into the cup 44 of approximately 0.030 inches by 0.030 inches. This embodiment of the mechanism works well with a solution of "Miracle Bubbles Number 8111", sold by Imperial Toy Corporation.
While there has been shown and described a preferred embodiment of the invention, it is to be understood that various other adaptations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.
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A toy which generates bubbles and shapes those bubbles into a recognizable form. The toy has a unique pump mechanism which injects air under pressure into a stream of liquid soap then forces the aerated stream through a screen to break up the stream into a multiplicity of bubbles. A removable shaper is arranged at the exit for bubbles from the pump mechanism. The shaper has an exterior which is the incomplete shape of an object recognizable to a child and a series of conduits which conduct the bubbles into porisions in which they complete the recognizable form.
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BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to an athletic ear guard assembly such as that worn by a wrestler and in particular to an ear guard assembly having removable ear pads to facilitate a thorough cleaning of the ear guard assembly.
During a wresting match, the opposing wrestlers are in close bodily contact with one another as well as in contact with the wrestling mat. As a result, it is possible that bacteria and or viruses carried on the skin or clothing of one wrestler can be transferred either directly to an opposing wrestler or can be transferred to the mat where it can be picked up by a subsequent wrestler. Such a transfer of bacteria or viruses is most likely with respect to diseases involving open wounds or sores such as cold sores. Of recent concern is the transmission of herpes simplex I between wrestling opponents. To help prevent the transmission of contagious diseases, increasing attention has been given to hygiene of wrestlers. It is recommended that wrestlers shower both before and after practice and that clean clothing be issued before each practice.
Wrestlers at virtually all levels of competition are required to wear protective head gear that covers the wrester's ears to prevent abrasion injuries to the ears. During use, the head gear collects perspiration and, by virtue of contact with the opponent and the wrestling mat, the head gear can collect bacteria and viruses. The perspiration provides an environment conducive for the growth of the bacteria or virus. Typical wrestling head gear has been constructed in a manner that creates numerous crevices for harboring perspiration and bacteria or viruses, making thorough cleaning and drying of the head gear relatively difficult.
Accordingly, it is an object of the present invention to improve the hygiene of wrestlers by providing head gear that can be easily cleaned to thoroughly remove all perspiration, bacteria, viruses etc., that are collected during a wrestling match.
It is a feature of the present invention to construct the head gear with a pair of concave cup sections for placement over the wearer's ears. Each cup section has a removable inner ear pad for direct contact with the wearer's ear. The inner ear pad is removable from the cup section by hand, enabling both the ear pads and the cup sections to be thoroughly washed, cleaned and dried.
It is a further feature of the present invention that both the inner ear pads and the concave cup sections are manufactured as flat molded parts that are later contoured into a concave shape. The flat molding simplifies the manufacturing process and facilitates printing of graphics to the outer side of the cup sections for team logos, etc.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the assembled head gear of the present invention;
FIG. 2 is an elevational view of one side panel of the head gear of the present invention shown as a flat molding;
FIG. 3 is an elevational view of the side panel shown in FIG. 2 after contouring to form a cup section;
FIG. 4 is a perspective view of an inner ear pad of the present invention shown as a flat molding;
FIG. 5 is a perspective view showing the inner ear pad being removed by hand from the cup section; and
FIG. 6 is a sectional view of the cup section and inner ear pad as seen from substantially the line 6--6 of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
The athletic ear guard of the present invention is shown in FIG. 1 and designated generally at lo. Ear Guard 10 is assembled from a pair of side panels 12 and 14 with side panel 12 being the right side panel and side panel 14 being the left side panel. The side panels are plastic injection molded in a substantially flat sheet form as shown in FIG. 2 with the right side panel 12. The left and right side panels are molded with integral upper straps 16 and 18 respectively and rear straps 20 and 22 respectively. The straps 16 and 20 of the right side panel are formed with a plurality of regularly spaced holes 24 and with an elongated through slot 26 at the ends of the straps. The slots 26 extend transversely to the length of the straps in the enlarged end portions 28. The end portions are enlarged in width so that the slots 26 are longer than the width of the main portion 30 of the straps 16 and 20.
The two side panels are assembled together by feeding the straps 18 and 22 of the left side panel through the slots 26 in the straps of the right side panel. The straps 18 and 22 of the left side panel are each equipped with four raised mounting studs 32 that are spaced to snap into the holes 24 of straps 16 and 20. The straps 18 and 22 are fed through the slots 26 in an outside to inside manner such that the surface 31 of the straps 18 and 22, with the raised studs 32, faces the straps 16 and 20. This enables the studs to be snap-fit into the corresponding holes 24. The size of the ear guard assembly is adjusted by appropriate selection of the holes into which the mounting studs are inserted.
A cup section 34 is formed by each of the side panels to cover the wearer's ears. The cup portion is formed by a main panel 36 and three legs 38, 40 and 42 extending from the main panel. The legs are spaced from one another and extend in the same direction from the main panel. To form the cup section, the legs are deflected so the distal end 39 of outer leg 38 and the distal end 43 of outer leg 42 overlay the distal end of the center leg 40 as shown in FIG. 3. The holes 44 at the distal end of each leg are aligned with one another forming a passage through the three legs once overlaid. The ends of the legs overlay one another by bending of the outer legs which causes the center leg as well as the main panel 36 to bend, forming the triangularly shaped cup section 34, shown in FIG. 3.
To aid in assembly, the distal end 41 of the center leg 40 is formed with two smaller holes 46 while the outer surface of the distal ends 39 and 43 of the other legs are each formed with a mounting stud 32 (not shown) for insertion into the holes 46. This holds the legs in position while a rivet 48 (shown in FIG. 5) is inserted through the now aligned holes 44. The cup section 34 has a concave inner surface 50 shown in FIG. 3 forming a concave cavity and a generally convex outer surface 52 shown in FIG. 1. The spaces between the legs 40 and 42 form vent slots 54 in the cup sections 34. At the periphery of the cup sections 34, along the three sides of the triangularly shaped cupped sections, a flange 56 is formed on the interior or concave side forming a generally U-shaped channel 58 best shown in FIG. 6.
An inner ear pad 60 is mounted in the cup on the concave side of the cup section 34 for contact with the wearer's ear. The inner ear pad 60 is molded flat of a soft, resilient, vinyl/rubber compound. The ear pad is in a flat triangulated shape with two sides 62 and 64 in an open appendage form and separated from the center portion 66 by spaces 68. Inner ear pad 60 is easily deformable or contoured into a concave shape to be mounted into the cup section 34 as shown in FIG. 1. The sides of the inner ear pads are formed with mounting flanges 70 for insertion into the U-shaped channels 58 at the periphery of the cup sections. The flanges thus retain the inner ear pads within the cup sections without the use of additional fasteners and in a manner that enables the inner ear pads to be removed and installed by hand as shown in FIG. 5. When installed, the spaces 68 between the legs of the inner ear pads align with the vent slots 54 in the cup sections to provide ventilation and to aid in hearing by the wearer.
The sides 62 and 64 of the inner ear pads and the center portion 66 are formed so as to create hollow chambers 72 between the inner ear pad and the cup section as shown in FIG. 6. During an impact, the inner ear pad will flex to absorb a portion of the impact energy, thus protecting the wearer's ears. The inner surface 74 of the inner ear pads is textured to lessen the total surface contact area with the wearer's ears and to also increase friction between the wearer's ears and the inner ear pad to reduce relative motion. Channels 76 are formed between the center section and sides of the inner ear pad at the upper end to aid in ventilation and drainage of perspiration.
The rivet 48, shown in FIG. 5, forms half of a snap fastener on the exterior surface of the cup section to enable a chin strap 76, having the complementary halves 78 of the snap fasteners mounted thereto, to be snapped to the ear guard assembly 10. The chin strap retains the ear guard assembly on the wearer's head. Slot 80 in the center leg 40 of the side panel enables the excess length 82 of the chin strap 76 to be hidden in the ear guard assembly to keep the excess strap away from the opponent's eyes.
After use, the inner ear pads can be removed by hand as shown in FIG. 5 for a thorough cleaning of the ear pads and the side panels 12 and 14. As a result, any accumulation of perspiration as well as bacteria or viruses that have been collected on the ear guard assembly from either the mat or the opponent, can be removed. The ear guard assembly of the present invention thus meets the objective of the present invention to aid in improving hygiene to stop the spread of illnesses among wrestlers.
The side panels, by being molded flat provide a convenient surface for the addition of a team logo or identification as indicated on the right side panel 12 shown in FIG. 1. Since the side panel is initially flat, graphics can be easily printed thereon. This provides an additional advantage of the ear guard assembly of the present invention as compared to ear guards molded with a convex outer surface.
It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
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Athletic ear guard assembly is disclosed having a removable inner ear pad that enables the ear pad to be removed by hand for a thorough cleaning of both the ear pad and the concave cup section into which the ear pad is mounted. The cup section is part of a side panel molded with a plurality of extending legs that are deflected to form the concave cup section. Likewise, the inner ear pad is also molded flat to provide ease in molding the components of the ear guard assembly. Thorough cleaning of the ear guard assembly is facilitated by easy hand removal of the ear pad to prevent the spread of bacteria and viruses among wrestling opponents.
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BACKGROUND
The present invention relates generally to computerized relational database systems and methods, and more particularly, to a method of evaluating relational database qualifications.
A relational database allows a user to modify and access a database by specifying the relationship of two or more relations (analogous to files) by writing an expression (also called a "qualification"). The flexibility of a relational database is what gives it its great user appeal. However there is a serious drawback to the flexibility of a relational database: processing the qualification is relatively slow, compared to conventional hierarchical databases.
Prior approaches to the processing of relational database qualifications used a combination of index and subsequent expression processing to complete the processing. Specifically the portion of the qualification that is not processed in the index is evaluated in the subsequent expression processing step. Since the expression processing step is many orders of magnitude slower than the index processing step, the choice of which portions of the qualification to treat as an index and which portions of the qualification to evaluate as expressions is critical to the product's processing speed.
Prior approaches protect themselves from this thorny problem by employing two tactics. First, the burden of specifying which index to create is shifted to the relational database user, and second, the user can specify which index to use manually. Hence the final responsibility for processing efficiency is placed upon the user. From the user standpoint this often makes achieving and maintaining good performance either costly or impossible. As a consequence the potential market advantage derived from a good database, or database based process, is lost.
Accordingly, it is an objective of the present invention to provide a method of speeding up relational database qualification processing. It is also an objective of the present invention to provide a method of speeding up relational database qualification processing that eliminates the need for a user defined index.
SUMMARY OF THE INVENTION
The present invention provides for a computer-implemented method that greatly speeds up relational database qualification processing, by emulating the function of a multiple dimension index, including constant expressions and joins involving complex functions. A unique feature of the present processing method is that it eliminates the need for a user defined index. The present invention performs relational database qualification processing in a much faster manner than conventional methods and requires no maintenance effort to maintain relational database performance. The advantages realized by the present invention are: more timely database response, reduced physical resource requirements, reduced manpower dedicated to maintaining relational database performance, and reduced collateral and dependent process impact.
In order to achieve the above and other objectives, the present invention provides for a computer-implemented processing method for performing relational database qualifications. The method comprises the following steps. First, establishing a command comprising a plurality of range variables related by join operators. Next, breaking up the qualification portion of the command into sub-expressions of the general type f(a) (join) f(b), or f(a) join "constant expression", where "a" and "b" are generic range variables. The sub-expressions are then mapped onto component joins that may be used repeatedly for numerous commands. The sub-expressions are a superset of the component joins. The component joins may contain boolean operators. Next, establishing a range variable processing order. Establishing the range variable processing order resolves processing ambiguities, both in ordering of the range variables and in specialized join types such as outer-joins, and eliminates false roots. Next, evaluating the component joins to make a partial index for each join, wherein the partial index comprises a pointer table such that it may be used simultaneously with other partial index. The result of conceptually combining the component joins and the processing order information are referred to as join vectors. Join vectors are a superset of partial index. Finally, looping over range variables using boolean processing to combine the join vectors, as needed, to complete the qualification. This process virtually eliminates the need for a subsequent processing step.
Breaking up the qualify portion of the command into sub-expressions involves manipulating the qualify portion of the command in accordance with the algebraic associative and commutative properties so that each part involves a join of either one range variable to a constant or two range variables to each other. Establishing a range variable processing order includes constructing a graph with range variables at the nodes and with generic joins between them, and wherein the generic joins are an indication of a functional relationship between two range variables. Each generic join is then assigned a directional component such that the range variable pointing to another range variable are referred to as parent and child respectively. The graph is then manipulated so that there are no ambiguous parent-child processing relationships between the ranges, such as circles, and there are no root range variables which may be eliminated by changing them into children. The parent-child relationship of one range variable to another through the generic joins is referred to as a "thread". Two parent range variables may have the same child range variable. Evaluating the component joins to make a partial index for each join involves evaluating the functional relationship of each tuple of the parent relation with each tuple of the child relation for the corresponding range variables and storing this result in tabular form. The use of space or processing saving techniques is not ruled out. Looping over range variables joining the established indices comprises looping over the range variables, starting at a root and then to each range that is a child with no unresolved parents. The join vectors are evaluated as required for the particular parent range variable to emulate a complex multiple dimension index as part of the looping over the range variables processing. If the product of evaluating the join vector is "null" looping over the range variables proceeds from child to parent, rather than from parent to child.
The present processing method has been tested in a production environment for use with relational databases for report generation applications. The measured performance gain for qualification processing is over two orders of magnitude. The overall performance gain was measured at over an order of magnitude. The baseline for these measurements consisted of several hundred commands from a production environment where continuous database performance tuning was in process. The reported gain is achieved without an abnormal amount of dedicated index storage. The present processing method is intended to operate upon an existing database developed and maintained using an established database product but adding functionality and/or processing capability, as well as serve as the basis for new relational database products.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 shows a flow diagram of a method of performing relational database qualification processing in accordance with the principles of the present invention;
FIGS. 2a through 2f show a more detailed flow diagram of the method of FIG. 1;
FIGS. 3a and 3b illustrate building a directed graph and assigning a range variable processing order;
FIG. 4 illustrates resolving processing ambiguities; and
FIG. 5 illustrates eliminating false roots.
DETAILED DESCRIPTION
By way of introduction, and for the purposes of comparison, the following data illustrates a relational database retrieval command processed by means of a conventional relational database qualification process. The joins that are processed by means of an index using conventional processing methods are identified by a numbered footnote.
__________________________________________________________________________ range of A is RELATION.sub.-- 1 range of B is RELATION.sub.-- 2 range of C is RELATION.sub.-- 3 retrieve (A.key,B.key,C.key) <targetlist>where A.comndid = C.comndid.sup.1 <qualify operations>and (B.setnum > 0 or B.fldnum > 2)and A.object = B.object.sup.2and A.setnum = B.setnum.sup.3and (B.setnum*128 + B.fldnum) = C.record.sub.-- idand B.set.sub.-- id = C.set.sub.-- id The joins which are processed using join vectors using the presentmethod aredesignated on the same command are identified by numbered footnotebelow. range of A is RELATION.sub.-- 1 range of B is RELATION.sub.-- 2 range of C is RELATION.sub.-- 3 retrieve (A.key,B.key,C.key) <target list>where A.comndid = C.comndid.sup.11 <qualify operations>and (B.setnum > 0 or B.fldnum >2).sup.12and A.object = B.object.sup.13and A.setnum = B.setnum.sup.14and (B.setnum*128 + B.fldnum) = C.record.sub. -- d.sup.15and B.set.sub.-- id = C.set.sub.-- id.sup.16__________________________________________________________________________
The method of the present invention is employed with a relational database that comprises at least one relation corresponding to a table (file), a plurality of attributes corresponding to columns (fields) of the relation, and a plurality of tuples corresponding to rows (records) of the relation. A qualify operation restricts the cross-product of two relations. The cross-product is formed by placing a tuple from one relation followed by every tuple from another relation. The qualify operation is comprised of joins that selectively control the commands operation, restricting the cross-product of the referenced relations. The qualify operation thus controls the target tuples retrieved by the operation. A target list controls the columns listed in the target tuple and hence projects the cross-product.
Referring now to the drawing figures, FIG. 1 shows a flow diagram of a computer-implemented method 10 of performing relational database qualification processing in accordance with the principles of the present invention. The method 10 comprises the following steps. The first step comprises establishing a query (command) 11 comprising a plurality of range variables related by join operators. The next step comprises breaking up the command (query) 12 into component joins of the type f(a) (join) f(b). The next step comprises establishing a range variable processing order 13. The next step comprises evaluating the sub-expressions 14 to establish partial index for each sub-expression, wherein the partial index comprises a pointer table. The final step comprises looping over range variables 15 evaluating the established join vectors as required.
The present method 10 processes all joins by means of join vectors, using boolean processes operating upon partial index, having a form such as f(a)=f(c) and f(b)=f(c), for example. In contrast, prior art processes use a cross-product of relations (as referenced through the range variables) for that portion of the relation that is not excluded by index processing, and then eliminates invalid target tuples which result from the cross-product by evaluating the cross-product results against the qualification statements.
The method of qualify expression evaluation of present method 10 may be illustrated as follows, with reference to ranges "B" and "C".
A No join vector is used for this range variable, the range variable is simply stepped once over its allowed range of values.
B index by join vector which results from boolean combination of partial index of constant expression upon "B" and sub-expressions of "A" and"B" for the current value of "A" explicitly the partial index for the sub-expressions:
A.setnum=B.setnum
A.objectid=B.objectid
(B.setnum>0 or B.fldnum>2)
C index by join vector which results from boolean combination of partial index of sub-expressions of "A" and "C" for the current value of "A", and of partial index for sub-expressions of "B" and "C" for the current value of "B" explicitly the partial index for the sub-expressions:
A.comndid=C.comndid
B.set -- id=C.set -- id
(B.setnum* 128+B.fldnum)=C.record -- id
The inclusion of the joins for A, B, to C is unique to the present processing method 10, and represents the central aspect thereof. However the ability to determine where to optimally resume the stepping process is also unique to the present processing method 10 and is an important optimization. An optimization of aggregate processing is also provided by the present method 10 wherein the dimensions of the aggregates are reduced through analysis of the aggregate expression and, if the join to the aggregate result fails, then a default result is joined.
Given the above, FIGS. 2a-2f show a more detailed flow diagram of the method 10 of FIG. 1. The method 10 breaks qualify expressions into component parts 12 so that each part involves a join of either one range variable to a constant or two range variables to each other. These component parts may contain OR operators. The inclusion of AND operators in a sub-expression is a performance decision. Examples of typical component parts of the qualify portion of a relational database command are:
A.setnum=B.setnum
(B.setnum*128+B.fldnum)=C.record -- id.
Component parts of the qualify expression in which the range variables are not segregated across the relational operators and that cannot be reprocessed to conform to this role, are often resource-expensive to produce and are excluded from join vector processing as a practical matter. The technique of assigning an alternative function into the partial index function, as an optimization to restrict cross-product evaluation of this class of joins, is useful. An example of such a join is
A.setnum+B.setnum=C.setnum.
The present method 10 as shown in FIGS. 2a-2f comprises building a directed graph 22 (examples are shown in FIGS. 3a, 3b, 4 and 5 with range variables at nodes and with all join relationships represented between them. The join relationships are an abstraction of the functional relationship between two range variables as expressed in the subexpressions. Before the directed graph 22 may be used to facilitate processing of the qualify expression, the method 10 resolves processing ambiguities 23, eliminates false roots 24, and finally assigns a range variable processing order 13.
Steps 22, 23, 24, and 13 are graphically illustrated 3a, 3b, 4 and 5, respectively. More specifically, FIG. 3a illustrates building a directed graph 22 and also illustrates assigning a range variable processing order 13. This is a directed graph with join directions randomly assigned. The join directions go in a circle making the parent-child relationship ambiguous. This directed graph also has only one possible processing order wherein each range variable appears before it's parent. The processing order is "A", "C", "B". FIG. 3b shows a directed graph with join directions rearranged so that the parent-child relationships are defined. Range "A" is now a root (having no parents). FIG. 4 illustrates resolving processing ambiguities 23. A range variable "D" has been added to illustrate a graph with two root ranges. Both "A" and "D" do not have parents. FIG. 5 illustrates eliminating false roots 24. A range variable "D" has been added to illustrate a graph with two root ranges. Both "A" and "D" do not have parents. The direction of the relationship of "C" and "D" in FIG. 5 has been reversed so that "D" is now a grandchild of "A". This eliminates "D" as a root.
Each of the sub-expressions assigned a directional component may then be combined with other similarly processed sub-expressions for a given range so that collectively the sub-expressions form a join vector. Join vectors of this type replace corresponding qualify expressions. In this way join vectors are combined to emulate a complex multiple-dimension index. Additional join vectors may be derived from components of the qualify expression that irreducibly represent a join between more than two range variables. In this case the join vector does not replace the portion of the qualify it is derived from, since it represents a superset of the original expression.
The first step in the processing of the join vectors in the method 10 initializes the join vectors 26. Then starting at a first range variable 27, which is always a root, the method 10 loops over all range variables 28, in accordance with the range variable processing order (step 13), and as a function of the join vector processing. The method 10 checks the range variable if it is subject to outer-join processing (looping step 28) which is a special value which the range variable may assume in addition to the tuple values it may assume for the particular relation which it represents. This value allows the method to bypass the range variable increment until the outer-join has been evaluated. The range variables become subject to outer-join processing when the method 10 requires that the range variables be transitioned up the range variable processing list and the parent of an outer join is transitioned and no target list tuple has been produced for that range variable value. Ranges that have been designated as outer-joined are ignored by range process step 29 until the parent range that is outer-joined is re-encountered, when the range variables record numbers are set for initialization, and step range function continues as before.
Then the method 10 determines the next or first value for the range variable for the tuples for the relation which it represents in range process step 29. If the range variable is subject to join vector processing then the join vectors are combined in a boolean process which takes intersections or unions, as appropriate, and determines the next or first range variable value. If no value results from the join vector processing then the range variable value is set to undefined so that re-evaluation of the parent range values may proceed directly. This is a unique feature of this process. If however the range variable is not subject to join vector processing then it is incremented through the tuple values for the relation which it represents, until it has assumed all allowed values and then it is set to undefined.
Next the range variable is tested 30 to determine if it has assumed a defined tuple value. If it has, the range variable is tested 31 if it is the last range variable in the processing order (step 13). If it is, then a test 32 is made to see if the qualify is completed in the join vector processing. If the qualify is completely processed in the join vector processing then the target list is processed 35 to produce the target list tuple result. If the qualify was not completely represented then the remainder of the qualify is completed 33, and if the remainder of the qualify evaluates as true, determined in qualify processing step 34 then the target list is processed 35 to produce the target list tuple result. Then the method 10 sets the range variables to indicate that a tuple was produced for all current range variable values and the backs up in the range variable processing list to the deepest range variable in the list that is not subject to outer join processing 36. If however, at looping step 28, the range variable was subject to outer join processing then the current position in the range variable processing order 13 is incremented 44 and looping step 28 is repeated.
In the method 10 if the range variable is undefined when tested in step 30, then if the range variable is the first range variable in the processing order then the evaluation of the command is complete 39. If the range variable is not the first range variable in the processing order then if the range variable is immediately subject to an outer-join parent 38 then a test is performed to check if a tuple was produced for the range variables parents current value 40. If no value has yet been performed for the parent then the outer join is propagated to all subject outer-join children 41, and the processing continues down the range variable processing list. Otherwise all child combinations have been eliminated or evaluated and processing proceeds up the range variable processing order 42. The ability of the method 10 to decrement its processing of the range variable processing order to the deepest failing parent join is a unique feature of the method 10 and is critical to the processing speed of the method. Other processing methods are not able to reverse the processing order until joins involving multiple parents are detected in the qualify processing step 34. If the qualify processing step 34 fails then the method 10 sets the current range variable to the deepest failing range variable in the processing order 45 and proceeds with the range variable processing loop in step 28.
Complete details of an implementation of the method 10 including a procedural description language (PDL) are provided in the PDL DESCRIPTION. Those skilled in the programing art may use this PDL to generate code to implement the method 10 of the present invention. The technique of processing the join vectors at the parent ranges, rather at the child ranges is also provided by the present invention, but is not described in detail since it is a simple extension of the method 10.
The processing method 10 has been implemented and tested in conjunction with relational database report generation. The processing method 10 achieved a reduction of over an order of magnitude in the processing time required to process the reports. An overall performance gain of a factor of 20 was initially realized. Additional relational database processing brought this gain down to a factor of 14, unadjusted for additional processing load, but this is in itself is very good, since the above-described processing method 10 automatically determines optimal processing for the database manipulations and relations and required no database analysis or optimization. The qualify processing time improvement realized with the method 10, without the inclusion of input and output processing, was 2-3 orders of magnitude for historically troublesome commands. This was achieved with no reduction in processing speed for commands involving simple joins. The baseline relational database that was used as a benchmark for relative performance evaluation was a Britton-Lee based setup conversion process that has been in use for over five years, and which was heavily optimized.
Thus there has been described new and improved method of evaluating relational database qualifications. It is to be understood that the above-described embodiment is merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.
PDL DESCRIPTION
A procedural description language (PDL) for the present method 10 described above is provided below. Those skilled in the programming art may use this PDL to generate code to implement method of the present invention.
__________________________________________________________________________Data StructuresPer Range Processing Order Outer-join flag PARENT- "Outer-join to child relations" CHILD - "Child (grandchild...) of outer-join" BLANK - "not a parent or a child"Outer-join status PASS - "Some Tuple produced for range current record" OUTERJOIN - "No record yet produced for range current recordMax records max value for record countCurrent record internal record countCurrent range range variable in processing list being looped onDirection 1 - go downward in range variable processing list -1 - go upward in range variable processing listSTEP RANGESInitialize "current-range" toInitialize "direction" to "1"Initialize all "outer-join-status" to "PASS"Initialize all "current-record" to "0"For "current-range", while > "0".sup. if "record-number" for "current-range" >= 0.sup. then if direction < 0 for each join if any "outer-join-status" is set to "OUTERJOIN" in list of joins then set "outer-join-status" to "PASS" perform propagate outer join set "direction" to "1" elseif ("outer-join-flag" is "PARENT" clear all subordinate range record numbers endif enddo if "range-type" is "SCAN" perform step scan type range else perform step join vector type range endif else if "range-type" is "SCAN" perform step scan type range else perform step join vector type range endif endifendif current-range" = "current-range" + "direction" if "current-range" is greater than "last-range" then perform Qualify processing and Target List processing <<< note: if the expression evaluates as true >>> <<< then all outer-join-status are set to "pass" set "direction" to "-1" decrement "current-range" endifendforINITIALIZE INDEX clear current-record for each parent/index set pointer-to-partial-index-list to first element in set-of-records set end-of-list to last element in set-of-records endforSTEP INDEX if current record = 0 set current pt to 0 for each index endif set "new-record" to "current-record + 1" set "index-point" to "first-index in partial index list ofcurrent-range" do while index point >o if new-record > "current-record of pointer-to-partial-index-list ofindex-point" then increment "pointer-to-partial-index-list of index-point" if "pointer-to-partial-index-list" > "end-of-list" then clear "record-number" for "current-range" set "direction" to "-1" set current range to deepest range where null result occured goto ::return:: endif elseif "new-record" < "current-record of pointer-to-partial-index-listof index-point" set "new-record" to "current-record of pointer-to-partial-index-list ofindex-point" reset "index-point" to "first-index" else set "index-point" to "next-index in partial index list" endif enddo set "current-record" to "new-record"for each join if "outer-join-flag" is "PARENT" set "outer-join-status" to "OUTERJOIN" endifendifset "direction" to "1"::return::STEP SCANincrement "current-record"if "current record" > "max record" then clear "record-number" of "current-range" set "direction" to "-1"else for each join if "outer-join-flag" is "PARENT" set "outer-join-status" to "OUTERJOIN" endif enddo set "direction" to "1"endif__________________________________________________________________________
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A computer-implemented method that speeds up relational database qualification processing by emulating the function of a multiple dimension index, including constant expressions and joins involving complex functions. The method comprises the following steps. Establishing a command comprising a plurality of range variables related by join operators. Breaking up the qualification portion of the command into sub-expressions of the general type f(a) (join) f(b), or f(a) join "constant expression", where "a" and "b" are genetic range variables. The sub-expressions are then mapped onto component joins that may be used repeatedly for numerous commands. The component joins may contain boolean operators. Establishing a range variable processing order to resolve processing ambiguities, both in ordering of the range variables and in specialized join types such as outer-joins, and eliminate false roots. Evaluating the component joins to make a partial index for each join, wherein the partial index comprises a pointer table such that it may be used simultaneously with other partial index. Finally, looping over range variables using boolean processing to combine the join vectors, as needed, to complete the qualification. The present method eliminates the need for a user defined index. A processing gain is achieved without the associated increase in storage requirements normally encountered with a multiple dimension index. The measured performance gain for join processing is about two orders of magnitude, while the overall performance gain was measured at about an order of magnitude.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 12/970,604, filed Dec. 16, 2010, which claims priority from U.S. Provisional Patent Application No. 61/287,077, filed Dec. 16, 2009. The contents of these applications are incorporated by reference in their entirety herein.
FIELD OF THE DISCLOSURE
[0002] Exemplary embodiments of the present disclosure relate to arrangements and methods for effecting an endoluminal anatomical structure, and more particularly to arrangements and methods for treatment of gastrointestinal lesions that currently require open abdominal surgery. The exemplary embodiment of at least one of the arrangements can provide an endoluminal colon chamber and a variety of maneuverable operating tools inside that chamber. For example, the exemplary embodiment of such arrangement can function as a miniature operating room inside the colon.
BACKGROUND INFORMATION
[0003] Current endoscopic technologies may not facilitate treating colon perforations, large polyps and tumors, and a significant colon bleeding effectively and safely. A gastrointestinal bleeding is a common and potentially life-threatening medical condition, which can complicate any polypectomy (polyp removal), and excision of colonic tumors. A colon perforation can occur when excessive mechanical force or excessive energy is inadvertently applied to a colonic wall. A colon perforation is a life-threatening condition and currently requires major emergency surgery to close the colon perforation and preclude fecal contamination of an abdominal cavity and resulting sepsis.
[0004] Consequently, many patients who develop large polyps, colon perforation, colon bleeding and other significant colon pathology currently have to undergo a major surgery and endure a significant operative trauma and, typically, painful and prolong recovery. Currently there are no effective and safe devices and methods for replacing major abdominal surgery in case of colon perforation or when large wide-based polyps need to be removed.
[0005] Thus, there may be a need to address at least some of the deficiencies described herein above.
[0006] U.S. Provisional Patent Application Ser. No. 61/247,605 filed on Oct. 1, 2009 and entitled “Detachable Balloon Catheter” describes exemplary embodiments of device and method for treatment of a gastrointestinal perforation and/or a gastrointestinal bleeding. The exemplary device can include a balloon catheter that can control bleeding by pressing on a bleeding area or/and prevents the gastrointestinal contents trespassing outside a gastrointestinal lumen into a body cavity by blocking an opening in the luminal wall or blocking the colon distal to the perforation. Such exemplary device can be inserted using an endoscope, and can allow a partial or complete withdrawal of an endoscope, while leaving the balloon at the target area. More specifically, the exemplary device and method can facilitate ceasing a colonic bleeding and blocking a colon perforation.
[0007] The Minos Megachannel is a large bore flexible reinforced tube, which is designed to be inserted over the standard colonoscope. After the colonoscope is removed, the tube can be used as a passage for insertion of different instruments into the colon.
[0008] Further, conventional endoscopes generally have one to two working channels, which likely do not have independent movements from the main body of the endoscope. As a result, when conventional flexible endoscopic instruments are inserted via such channels into the intestinal lumen, an operator can only manipulate these instruments axially (e.g., forward and backward movements), and possibly somewhat rotationally. In addition, since the conventional instruments can only be advanced from the tip of the endoscope towards the target lesion axially and in front of the endoscopic image, the conventional instruments have only limited functionality.
[0009] Accordingly, there may be a need to address at least some of the deficiencies described herein above.
SUMMARY OF EXEMPLARY EMBODIMENTS OF THE PRESENT DISCLOSURE
[0010] Exemplary embodiments of the present disclosure can address most if not all of the above-described needs by providing device and method for a treatment of, e.g., a gastrointestinal perforation, bleeding, removal of large polyps, and/or other significant endoluminal pathology, for example, colonic pathology.
[0011] According to one exemplary embodiment of the present disclosure, the device can function as a miniature operating room inside the lumen, for example, colon, and providing an operator with advanced endoluminal functionalities replicating capabilities of a surgical suite. The exemplary device of the present disclosure can provide such miniature endoluminal operating room, chamber or at least partial enclosure, and the ability to utilize a variety of articulating surgical instruments, which can operate within, at or around the chamber.
[0012] According to one exemplary embodiment of the present disclosure, the exemplary arrangement/device can be introduced after a standard diagnostic colonoscopy is performed. An exemplary balloon guide catheter, as described in U.S. Provisional Patent Application Ser. No. 61/247,605, or a large endoluminal channel such as a Minos Megachannel manufactured by, e.g., Minos Inc., can be used to facilitate the insertion of the exemplary device according to the present disclosure.
[0013] In another exemplary embodiment of the present disclosure, the arrangement/device can contain a plurality (e.g., three) primary sections, e.g., a handle, a multi-lumenal tube, and an expandable chamber.
[0014] It is possible to utilize endoluminal channels and associated articulating endoluminal instruments with the exemplary embodiments of the arrangement/device. To that end, the exemplary arrangement/device can include a multi-lumen tube. The multi-lumen tube can include lumens for at least two special tools or tool-channels, or three or more special tools and/or tools-channels. In addition, the multi-lumen tube can include other channels, which can be used for, as an example, air, water, vacuum delivery, etc. The exemplary arrangement/device can also include channel for scope and illumination; and lumens for a chamber activation and lumen for a balloon guide catheter as indicated herein.
[0015] According to still another exemplary embodiment of the present disclosure, the arrangement/device may also contain a chamber located distally, which can be expanded to different sizes within the colon, thus producing a relatively large working space near the targeted luminal lesion. The exemplary arrangement/device can be structured to manipulate the tools and/or tool-channels in such a way that distal ends of one or more of such tools and/or channels can operate within or at the chamber, and approach the lesion from multiple or even all directions, and using numerous angles. In addition, at least one tool-channel can accommodate a large diameter tool, for example, a special endoscopic stapler.
[0016] In a further exemplary embodiment of the present disclosure, the arrangement/device can further contain a control handle, e.g., at or about its proximal end. The handle can be provided in a similar way and/or shape as handles of other endoscopes', while including further more ports, such as, e.g., tool-channels ports, a balloon guide catheter port, a special lever to control the opening and closing of the device chamber, etc.
[0017] According to a still further exemplary embodiment of the present disclosure, the arrangement/device can include and/or utilize particular tools or tool-channels. For example, the distal ends of the particular tools and/or tool-channels can be operated in all directions and within all degrees of freedom using the actuating mechanisms, which can be controlled at or about the proximal ends of the device. The exemplary instruments/tools (e.g., grasper(s), scissor(s), dissector(s), others), which can be inserted in the special tools or tool-channels, may be manipulated (e.g., rotated, moved axially forward and backward, bent at the distal end at any desired angles) by manipulating the tool-channels.
[0018] In a further exemplary embodiment of the present disclosure, the arrangement/device can facilitate a lateral and/or multi-directional movements of the instruments/tools, in addition to the axial and rotational movements thereof. Since the exemplary tool-channels can be manipulated independently from the main endoscope and other tool-channels, the instruments/tools can approach the lesion from the different and possibly limitless directions. For example, when the endoscopic instruments/tools approach the lesion from the sides in relation to the main longitudinal axis and, hence, without blocking the endoscopic image, a so-called and well-known in laparoscopy “tri-angulation” can be achieved. The tri-angulation can be a preferable technique for achieving the endoscopic arrangement's/device's improved functionality and safety. Such exemplary methodology can mimic the functionality of well-established surgical operating room environments. The exemplary tool-channels can be advanced in the lumen from the working ports of the multi-lumen tube and/or be at least partially pre-fixed to the element(s) of the associated expandable chamber. The exemplary tool-channels can also be advanced directly into the body lumen (e.g., an intestinal lumen), into the chamber space, and/or initially advanced along the element(s) of the chamber and then further into the body lumen or into the chamber space.
[0019] As an alternative according to yet another exemplary embodiment of the present disclosure, the arrangement/device, alternatively to the tool-channels or in combination with the tool-channels, can use conventional and/or articulating instruments/tools with at least two degree of freedom.
[0020] In addition, according to a further exemplary embodiment of the present disclosure, a method can be provided for using the exemplary arrangement/device in the body lumen (e.g., colon). For example, using such exemplary method, it is possible to perform a standard colonoscopy and identify a lesion that may not be treated using standard endoscopy and techniques. A balloon guide catheter can be inserted, the balloon inflated and the standard colonoscope (the balloon catheter and inflated balloon are left in place) removed. The balloon guide catheter can be used as a guide-wire to facilitate the insertion of the exemplary arrangement/device. The exemplary arrangement/device can be inserted over the balloon guide catheter, e.g., until the chamber is in the proximity to the lesion. The chamber can be deployed and adjusted to certain dimensions. It is possible to readjust the chamber during the procedure, as needed. Further, an operative area can be cleaned with a provided suction catheter. Further, a proximal balloon, a distal balloon or both proximal and distal balloons can be inflated for the treatment area isolation. Tool-channels can be inserted, followed by or in conjunction with an insertion of the instruments/tools into the tool-channels. It is also possible to manipulate the tool-channels to optimize and facilitate the instruments'/tools' approach to the lesion. Further, a procedure can be performed, for example, closing a colonic perforation, removing a large colon polyp or tumor, stopping a bleeding, closing diverticuli, removing an appendix, treating other body luminal lesions.
[0021] Further, exemplary embodiments of devices and method for affecting at least one anatomical tissue can be provided. A configuration can be provided that includes a structure which is expandable (i) having and/or (ii) forming at least one opening or a working space through which the anatomical tissue(s) is placed in the structure. For example, the structure, prior to being expanding, can have at least one partially rigid portion. In addition, or as an alternative, upon a partial or complete expansion thereof, the structure can be controllable to have a plurality of shapes. Further, the structure can be controllable to provide the working space with multiple shapes and/or multiple sizes.
[0022] According to yet another exemplary embodiment of the present disclosure. prior to the structure being expanded, the structure can have at least one partially rigid portion that is expandable to form a non-cylindrically-shaped working area which can be asymmetrical. Further, an endoscopic arrangement can be included that is structured to be provided in the working area, and that can include a further configuration that facilitates an articulation of a tip portion of the endoscopic arrangement within the working area. The further configuration can include a mechanical bending arm which can facilitate the tip portion to be moved within the working area so as to facilitate a visualization of at least one object in the working area. An arrangement can also be provided which is coupled to the structure, and which can provide (i) at least one lumen and/or (ii) at least one instrument there through to reach the working area. For example, a distance between a tip of the arrangement and a distal portion of the structure that is farthest away from the arrangement can be controllable to adjust a shape and/or a size of the working area.
[0023] In still another exemplary embodiment of the present disclosure, upon a complete or partial expansion of the structure, the structure can be controllable to have a plurality of shapes. In addition, the structure can be controllable to provide the working space with multiple shapes and/or multiple sizes. The structure can have an expanded portion and an unexpanded portion, and form an axes of extension of the device, a first distance to a highest point of the expanded portion can be different than a distance to an non-expanded portion. For example, the first distance can be greater than the second distance. The structure can be controllable to adjust the first distance, while maintaining the second distance approximately the same. Further, in an non-expanded state, the configuration can be controllable to provide an articulation thereof in a plurality of directions.
[0024] According to a further exemplary embodiment of the present disclosure, a first arrangement can be provided at a distance from the configuration and the anatomical structure(s). In addition, a second arrangement can be provided between the first arrangement and the configuration, and can have at least one lumen that is connected to the first arrangement. Further, a third arrangement can be provided which may be structured to move through the lumen at or near the anatomical structure(s), and which can be configured to be provided in the structure. The lumen(s) can comprise a multi-channel tube, and the structure can be structured to be movable through the multi-channel tube and rigidly connected thereto so as to limit or reduce a movement of the structure with respect to the multi-channel tube. At least one movable camera and an illumination arrangement can be provided within or near the configuration, and movable through the multi-channel tube. At least one movable vacuum catheter and/or irrigation catheter can be provided within or near the structure, and movable through the multi-channel tube.
[0025] In one exemplary embodiment, the lumen(s) can comprise a tube channel and/or a tool channel, which is/are movable therein. The tool channel can be axially movable, rotatable, and/or bendable, and can include at least one wire which is configured to bend the tool channel. A distal end of the tool channel can be configured to reach any point inside or near the structure. The tool channel can include at least one wire which can be usable to bend the tube or the tool channel at least in one direction and in at least at one angle which is between 0 and 180 degrees. For example, a distance between the working channel and the structure can be controllable by moving at least one wire in the working channel toward and/or away from the structure. An endoscope can be provided within or near the configuration, and movable through the multi-channel tube to reach the working space. The endoscope can include an image sensor provided on a flexible shaft to visualize at least one portion of the tissue(s).
[0026] According to yet a further exemplary embodiment of the present disclosure, the structure can have at least one flexible strip or at least one wire and/or two or more flexible strips or wires. At least one of the strips or wires can have a pre-formed shape to provide the desired geometry of the working space. In addition, at least one balloon can be provided or two or more balloons. At least one of the balloons can be an asymmetric shape and/or a symmetric shape. The balloon(s) can be positioned proximal to the structure. According to one exemplary variant, a first balloon and a second balloon can be provided, where the first balloon is provided distally in relation to the structure, and the second balloon is provided proximally in relation to the structure. The structure can be composed of wires and/or a mesh. Such wires/mesh, prior to being expanded, can have (i) at least one partially rigid portion, (ii) upon a partial or complete expansion thereof, can be controllable to have a plurality of shapes, and/or (iii) can be controllable to provide the working space multiple shapes and/or multiple sizes.
[0027] These and other objects, features and advantages of the exemplary embodiment of the present disclosure will become apparent upon reading the following detailed description of the exemplary embodiments of the present disclosure, when taken in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Further objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments of the present disclosure, in which:
[0029] FIGS. 1 and 1A , are schematic cross-sectional illustrations of an exemplary embodiment of an arrangement/device comprising a multi-lumen extrusion tube, and multiple tubes inside one large tube in accordance with the present disclosure;
[0030] FIG. 2 is a perspective view of an exemplary embodiment of the arrangement/device according to the present disclosure comprising which includes a nitinol strips chamber in an closed position;
[0031] FIG. 2A is a perspective illustration of the arrangement/device of FIG. 2 with the chamber formed by flexible strips in an open position;
[0032] FIG. 2B is a side view of the arrangement/device of FIG. 2 with the chamber formed by flexible strips in another position;
[0033] FIG. 2C is a side view of the arrangement/device of FIG. 2 with an overtube covering the chamber that is in the closed position according to an exemplary embodiment of the present disclosure;
[0034] FIG. 2D is a side view illustration of the arrangement/device of FIG. 2 with a scope that is provided in one of the working channels and facilitating a field of view therefor according to another exemplary embodiment of the present disclosure;
[0035] FIG. 3 is a perspective view of another exemplary embodiment of the arrangement/device according to the present disclosure which includes the chamber made from two metal strips;
[0036] FIG. 4 is a side cross-sectional view of an exemplary embodiment of the arrangement/device according to the present disclosure which includes the chamber made from two asymmetric balloons;
[0037] FIG. 5 is a perspective view of another exemplary of another exemplary embodiment of the arrangement/device according to the present disclosure which includes the chamber made from one asymmetric balloon together with the balloon guide catheter;
[0038] FIG. 6 is a perspective view of another exemplary of still another exemplary embodiment of the arrangement/device according to the present disclosure which includes the chamber made from metal wires braid;
[0039] FIG. 7 is a perspective view of a further exemplary of yet another exemplary embodiment of the arrangement/device according to the present disclosure which includes the nitinol strips chamber with two blocking balloons at both sides;
[0040] FIG. 8 is a side view of another exemplary of yet a further exemplary embodiment of the arrangement/device according to the present disclosure which includes the chamber with cameras;
[0041] FIG. 9 is a right side perspective view of a further exemplary embodiment of the arrangement/device according to the present disclosure which includes a particular handle;
[0042] FIG. 9A is a left side perspective view the exemplary arrangement/device of FIG. 9 ;
[0043] FIG. 10 is a perspective view of yet another exemplary of yet another exemplary embodiment of the arrangement/device according to the present disclosure which includes a vacuum catheter;
[0044] FIG. 11 is a perspective view of yet another exemplary of another exemplary embodiment of the arrangement/device according to the present disclosure which includes a tool-channel;
[0045] FIGS. 12, 12A and 12B are different illustrations of a preferred embodiment of still another exemplary embodiment of the arrangement/device according to the present disclosure which includes a tool-channel elevator with FIG. 12 showing the device in a first bent position, FIG. 12A showing the device in a second bent position, and FIG. 12B showing the device in a non-bent position; and
[0046] FIG. 13 a perspective view of yet another exemplary of another exemplary embodiment of the arrangement/device according to the present disclosure which includes the tool-channels inside the chamber thereof.
[0047] Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure as defined by the appended claims.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0048] According to one exemplary embodiment of the present disclosure, a device, an arrangement and a method can be provided for treatment of, e.g., conditions associated with body lumen(s) or/and cavities, for example, gastro-intestinal conditions, including but not limited to a gastrointestinal perforation, bleeding, large polyps or/and tumors, diverticuli, appendix, and others.
[0049] The exemplary embodiments of the arrangement/device according to the present disclosure can provide various functions, which may be the same and/or similar to the surgical functions provided in the surgical operating room, therefore, thus representing a miniature operating room within a lumen (e.g., of a body), such as, e.g., colon and allowing to replace a major surgery, e.g., an open abdominal surgery.
[0050] For example, as shown in FIGS. 2 and 2A , the exemplary embodiment of the arrangement/device 1 according to the present disclosure can provide an endoluminal chamber which can also be at least partial enclosure, such as, e.g., an endoluminal colon or an intra-colon chamber/enclosure, and include various maneuverable operating instruments and/or tools 11 within the chamber 10 . The exemplary arrangement/device 1 can be inserted after one or more relevant lesions is/are identified, e.g., during standard colonoscopy. A particular balloon guide catheter 4 , e.g., such as described in U.S. Provisional Patent Application Ser. No. 61/247,605 filed on Oct. 1, 2009, or Mega-channel such as Minos Inc. Mega-channel, can be used to facilitate an insertion of the exemplary arrangement/device 1 .
[0051] According to certain exemplary embodiments of the present disclosure, the arrangement/device 1 can be a particularly-designed endoscope, such as, e.g., a colonoscope. As shown in FIGS. 9 and 9A , according to certain exemplary embodiments, the arrangement/device I can include, e.g., an exemplary handle 20 (see FIGS. 9 and 9A ), an exemplary multi-lumen tube 30 (see FIGS. 1, 1A, 3, 7, 8 and 13 ), and an exemplary expandable chamber 10 (see FIGS. 5, 7, 10 and 13 ). In addition, the arrangement/device 1 can include standard and particular exemplary instruments/tools 11 (see FIGS. 8, 12 and 13 ) and/or exemplary tool channels (see FIG. 13 ).
[0052] As indicated herein above, the exemplary arrangement/device 1 can include the multi-lumen tube 30 . Such exemplary multi-lumen tube 30 can be made from a single extrusion polymer tube 31 having multiple lumens {see FIG. 1 }, and/or made in a standard endoscopic equipment configuration using a collection of single or multi-lumen tubes 32 of different sizes that are enclosed by a single, large, flexible tube 33 (see FIG. 1A ). External and internal tubes can be simple polymer tubes and/or reinforced tubes or braided tubes, as known in the art. The external tube 33 can have a diameter that is large enough to contain all inner tubes 32 provided for the exemplary arrangement/device 1 . The exemplary multi-lumen tube 30 can include at least one lumen, and, e.g., possibly 2 to 4 or more lumens for 2 to 4 or more exemplary instruments/tools 11 and/or tool-channels 40 , and possibly additional lumens, for example, for a air insufflation 34 , water irrigation 35 , vacuum 36 , lumen for wiring and/or fibers for cameras and illumination 37 , lumen for a balloon guide catheter 4 , lumen for chamber expansion control 38 , and/or lumen for proximal balloon inflation 39 , as shown in the exemplary embodiment of FIG. 1A .
[0053] For example, according to particular exemplary embodiments of the present disclosure, the arrangement/device 1 can contain a distal chamber 10 that can be expanded to different sizes inside the colon, thus likely creating relatively large or sufficient working space near the lesion to be treated. The exemplary chamber 10 can provide a space for manipulations of multiple tools and/or tool-channels in such a way that several tools can approach the lesion from all sides and directions, as shown in, e.g., FIGS. 3, 7, 8 and 13 . The exemplary multi-lumen tube 30 , e.g., having a diameter between 10 mm to 40 mm, can accommodate at least one tool-channel, which can in turn accommodate, e.g., a non-standard instrument, for example, an endoscopic stapler, both having a sufficient size for a particular purposes thereof.
[0054] According to one exemplary embodiment of the present disclosure, the exemplary chamber 10 can be constructed from at least one, and possibly two or more flexible metal strips, fibers or wires 12 , which can be made from a flexible material, such as, e.g., Nitinol, as shown in FIGS. 2, 2D and 3 . These exemplary strips, fibers or wires can be composed of other materials as well, including but not limited to surgical plastic or other materials. The exemplary strips, fibers or wires 12 can be substantially straightened (or slightly-to-moderately bent as needed during steering the device through the lumen) when the chamber 10 (providing a working space) is in non-deployed position (see FIGS. 2 and 2C ), and are substantially bent when actuated by a control lever 23 in the handle 20 , hence, enlarging the chamber 10 and creating a larger working space inside the colon, as shown in FIGS. 2A, 2B, 2D and 3 . For example, pushing or pulling the exemplary strips, fibers or strips 12 can be performed with a tube 19 that can slide in the lumen 38 by pulling and/or pushing the tube 19 proximal end lever 23 in the handle 20 , as shown in FIGS. 2, 2D, 3, 9 and 9A . Further, the guide catheter 4 can be inserted inside the tube 19 . The exemplary strips 12 can be covered by a soft polymer cover to avoid possible inner colon tissue damage.
[0055] According to an exemplary embodiment of the present disclosure, as shown in FIGS. 2-2D , the chamber 10 it can be deflected by pulling on the exemplary strips, fibers or wires 12 , or the chamber 10 can be opened when the exemplary strips, fibers or wires 12 are pushed forward from the handle 30 . In thus manner, the exemplary strips, fibers or wires 12 increase working space with in the chamber 30 to facilitate the anatomical structure to be pulled into the chamber 10 by other instruments/tools 11 being manipulated from the handle 30 , as described in further details herein, and shown in, e.g., in FIG. 8 .
[0056] Further, as shown in FIGS. 2B and 2D , the exemplary strips, fibers or wires 12 can be covered with a protective cover portions 70 so as to reduce damage being caused by the exemplary strips, fibers or wires 12 when they are actuated to expand the chamber 10 (i.e., which causes the exemplary strips, fibers or wires 12 to push on the surrounding tissue). As shown in FIG. 2C , the arrangement/device 1 can also include an overtube 65 which can be pushed forward toward the front of the arrangement/device 1 so as to cover the collapsed chamber 10 (e.g., to facilitate insertion and removal and containing the specimen), and pulled back to prepare for the chamber 10 for its expansion. FIG. 2D shows an illustration of the arrangement/device 1 of FIG. 2 with a scope 60 (including a camera and at least one light illuminating source) that is provided in one of the working channels 40 and facilitating a field of view 54 for positioning and propelling the exemplary arrangement/device 1 .
[0057] When the instrument 1 reaches the desired position within the body, the scope 60 can be retracted inside the chamber 10 , e.g., via the working channel 40 to facilitate visualization inside and/or near the chamber 10 . According to another exemplary embodiment of the present disclosure, an articulating scope (which can perform similar functions as that of the scope 60 ) can be provided through one or more of the working channels 40 into the chamber 10 . Such articulating scope can be configured to illuminate and/or provide images of the anatomical structure and tools inside and/or near the chamber 10 . The articulating scope can have a distal portion that can rotate in 360 degrees and bend to provide an end part thereof so as to illuminate and visualize any portion of the anatomical structure and the tools inside and/or near the chamber 10 at any angle.
[0058] In another exemplary embodiment of the present disclosure, as shown in FIG. 7 , the strips 12 can be proximally connected to a first cap 14 , which can be made from a solid material. The first cap 14 can have multiple holes for most or all lumens 32 . The strips 12 can also be distally connected to a second cap 15 which can be smaller in diameter than the first cap 14 , to facilitate a passage of large specimens, for example, polyps into the area of the chamber 10 . The distal second cap 15 can include a hole for insertion of the balloon guide catheter 4 . Alternatively or in addition, the exemplary chamber 10 can be made from two asymmetrical balloons 5 , 16 , as shown in the exemplary embodiment of FIG. 4 . For example, the balloons 5 , 16 can create space for the chamber 10 and the exemplary instruments/tools 11 when inflated. Alternatively or in addition, the exemplary chamber 10 can be provided using the proximal balloon 16 and the distal balloon 5 , being connected to one another via their attachment to the balloon guide catheter 4 , as shown in FIG. 5 . Further alternatively or in addition, the exemplary chamber 10 can be provided by a braided metal wire net 17 having an opening 18 at desired location, as shown in FIG. 6 .
[0059] In another exemplary embodiment of the present disclosure, at least one, and possibly two or more balloons can be used with the chamber 10 that is made from strips 12 made from a bendable material (e.g., metal). The exemplary balloon(s) 5 , 16 can assist in blocking and/or isolating the chamber 10 from the rest of the colon, hence, minimizing and/or preventing the inflow and outflow of liquids and solids from and/or to the chamber 10 , while the exemplary strips 12 can provide a substantially rigid and stable working space and facilitate treatment of the lesion. For example, as shown in FIG. 7 , the first symmetric or asymmetric balloon 16 can be provided in proximal to the chamber 10 or the position of the strips 12 . The second balloon 5 can be provided at the position that is distal to the strips 12 . Alternatively, the second balloon 5 that can be connected to the guide catheter 4 .
[0060] According to still another exemplary embodiment of the present disclosure, the arrangement/device 1 can include at least one camera and an illumination apparatus to provide sufficient light to the area of interest. For example, camera or cameras and illuminating component can be movable or fixed in the arrangement/device 1 , for example, to the chamber 10 . In one exemplary embodiment shown in FIG. 2D , the scope/front camera 50 can be used to facilitate the insertion of the arrangement/device 1 into the colon. Referring to FIG. 8 , e.g., at least one, two or more additional and possibly fixed cameras 51 can be positioned so to facilitate image capture at a location of the lesion. Exemplary field views 54 of the cameras 51 can overlap, and such overlap may facilitate visualization if one or more instruments/tools blocks or adversely affects view of one of the cameras. For example, illumination can be provided by a variety of ways, e.g., by LEDs 52 , 53 . Exemplary front LEDs 52 can be used for the front camera 50 , and in-chamber LEDs 53 can be used for the illumination in or at the chamber 10 . Alternatively or in addition, a conventional flexible endoscope, having distal bendable section, can be used instead of or together with the fixed camera(s) 51 and illumination via the LEDs 52 , 53 .
[0061] As shown in FIGS. 9 and 9A , the exemplary arrangement/device 1 according to a further exemplary embodiment of the present disclosure can include a control handle 20 at or about its proximal end. The exemplary handle 20 can have similar shape and configuration with respect to other conventional endoscope's handles, while likely having additional channel ports and actuators than standard endoscope. For example, the ports in the handle 20 can include at least one, and possibly 2-4 or even more ports for the tool-channels 21 , balloon guide catheter port 22 and particular lever 23 to control the opening and closing of the chamber 10 . Additional ports can include, but not limited to, a luer port 24 for a proximal balloon inflation, and a port 26 of a vacuum catheter 25 or an irrigation catheter. The handle 20 can include switches 27 , 28 for air insufflations, water irrigation and vacuum activation, as well as switch (not shown) for switching camera(s) between frontal and inner locations.
[0062] As illustrated in FIG. 10 , the exemplary arrangement/device 1 according to a still further exemplary embodiment of the present disclosure can include a vacuum catheter with a bent tip 25 , inserted in a vacuum lumen 36 through a vacuum port 26 . The vacuum catheter can operate as a standalone (as describe herein), and/or may be inserted into tool channel 40 and deflect. Further, the vacuum catheter can be manipulated to reach all or most areas inside and around the chamber 10 , hence, providing an access for elimination of liquids and solids from and around the chamber 10 . In another exemplary embodiment of the present disclosure, the chamber 10 can include bendable and steerable section, which can be actuated at the lever 23 , which when pulled, the instrument 1 is articulated, and when pushed, the chamber 10 is opened (or increased in size). Thus, movements of the exemplary arrangement/device 1 in the colon can be facilitated. According to a further exemplary embodiment, a locking mechanism can be provided which can, e.g., rotate one or more times (e.g., counterclockwise or counter-clockwise) to lock the lever 23 .
[0063] According to still another exemplary embodiment of the present disclosure, the exemplary arrangement/device 1 can include the instruments/tools 11 and/or tool-channels 40 , as shown in FIG. 11 . When the exemplary instruments/tools 11 are inserted in the tool channels 40 , distal ends 41 thereof change the position(s) and/or shapes of the instruments/tools 11 , for example, rotated, axially moved, bent at desired angles, whenever the position and shape of the associated tools channels 40 are changed, as shown in FIGS. 12 and 12A (compare to FIG. 12B ). The tool channels 40 can be actuated and manipulated at or about proximal end of the exemplary arrangement/device of the present disclosure. The described maneuverability of the tool-channels 40 , for example, their distal ends 41 provide and/or facilitate multidirectional and multiangular approach to the target lesion.
[0064] For example, the tool-channels 40 can include at least one, and preferably two, three or more lumen tubes 42 , which can be made of polymer, possibly having high torque-ability, low friction, connected at or about their distal ends to an additional section 41 , which can have “elevators” 43 . The exemplary polymer tube(s) 42 can be reinforced with other materials to change its/their structural or/and functional properties. The elevator 43 can be a flexible bendable section, made, e.g., from a laser cut nitinol tube 44 , and/or actuated, e.g., bent, using one or two metal wires 45 . The instruments/tools 11 can be inserted in the first (e.g., relatively large) lumen of the tube 42 , and the wire 45 can be inserted in the second (e.g., relatively small) lumen of the tube 42 .
[0065] As shown in FIG. 13 , the ability of the tool-channel tubes 42 to move, independently or simultaneously, axially (e.g., pushing, pulling directions), rotate and bend using the elevator 43 , facilitates the instruments/tools 11 or/and the tool-channels 40 in reaching any point within and around the chamber 10 , and can provide possibly an unlimited range of instrumental freedom within the working space. For example, as shown in FIG. 11 , the tool channel 40 can include one or more handles 46 connected to the tube 42 at or about a proximal side of the tube 42 , and can be used for a manipulation of the elevator 43 , and utilize a port 47 for an insertion of the exemplary instrument/tool. 11 . The exemplary tool-channel handle 46 can include a slider or knob 48 which can be used to actuate, e.g., pull and release a wire 45 , as shown in FIG. 12 . Any standard tool(s) can be used with the exemplary tool-channel(s) 40 . Alternatively or in addition, articulating tools having maneuverable distal ends, e.g., with at least two degrees of freedom, can be used.
[0066] According to yet a further exemplary embodiment of the present disclosure, a method for implementing the exemplary arrangement/device 1 according to the present disclosure can be provided. Such exemplary method can be utilized as follows:
[0067] i. Perform a standard colonoscopy and identifying a lesion that may not be treated using standard endoscopy and techniques.
[0068] ii. Insert a balloon guide catheter, inflating the balloon and removing the standard colonoscope (the balloon catheter and inflated balloon are left in place). The balloon guide catheter can be used as a guide-wire to facilitate the insertion of the exemplary arrangement/device 1 .
[0069] iii. Insert the exemplary arrangement/device lover the balloon guide catheter, until the chamber is in the proximity to the lesion.
[0070] iv. Deploy and adjust the chamber 10 of the exemplary arrangement/device 1 to preferred dimensions. Readjust the chamber 10 during the procedure as needed.
[0071] v. Clean an operative area with a provided suction catheter. If desired, inflate a proximal balloon, a distal balloon or both proximal and distal balloons for the treatment area isolation.
[0072] vi. Insert the tool-channels.
[0073] vii. Insert the instruments/tools into the tool-channels. Manipulate the tool-channels to optimize and facilitate the instruments/tools approach to the lesion.
[0074] viii. Perform a procedure, e.g., closing a colonic perforation, removing a large colon polyp or tumor, stopping a bleeding, closing diverticuli, removing an appendix, treating other body luminal lesions.
[0075] The foregoing merely illustrates the principles of the present disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. For example, more than one of the described exemplary arrangements, radiations and/or systems can be implemented to implement the exemplary embodiments of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the present disclosure and are thus within the spirit and scope of the present disclosure. In addition, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it is explicitly being incorporated herein in its entirety. All publications referenced herein above are incorporated herein by reference in their entireties.
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Exemplary embodiments of devices and method for affecting at least one anatomical tissue can be provided. A configuration can be provided that includes a structure which is expandable (i) having and/or (ii) forming at least one opening or a working space through which the anatomical tissue(s) is placed in the structure. For example, the structure, prior to being expanding, can have at least one partially rigid portion. In addition, or as an alternative, upon a partial or complete expansion thereof, the structure can be controllable to have a plurality of shapes. Further, the structure can be controllable to provide the working space with multiple shapes and/or multiple sizes.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/508,160 filed Oct. 2, 2003 entitled “COMPACT JACQUARD SELECTING CARD USING PIEZOELECTRIC ELEMENTS”, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to selecting cards for Jacquard-type equipment. More specifically, the present invention relates to a piezoelectric actuated selecting card for use in a Jacquard loom.
[0004] 2. Description of the Prior Art
[0005] The use of Jacquard selection devices in weaving looms to produce intricate patterns by controlling the lifting of selected warp yarns is well known in the art. The separation formed between the lifted warp yarns and the non-lifted warp yarns is referred to as the shed. The Jacquard mechanism allows for independent movement of each warp yarn by controlling hooks (latches, catches) which engage matching hooks on rods (healds) connected to each warp yarn in a harness. A lifting device (or board) is used to raise or lower those warps in the harness whose corresponding hooks have been engaged. By coordinating the movement of the hooks, sequences of warp yarns can be selected and lifted while filling yarns are passed through the shed. In this manner, the Jacquard selection device is used to create the woven pattern.
[0006] Jacquard selection devices can be used in looms in either a closed shed or an open shed arrangement. In the closed shed arrangement, a single lifting device having an engaging hook for each warp in the harness is used. Whereas, the open shed configuration uses a double hook system of two lifting devices which provide pairs of engaging hooks which connect with pairs of (ascending and descending) rods that lift a single warp. The open shed configuration has two lifting devices and requires only a single move of each lifting device to create the shed, while the closed shed configuration has one lifting device but requires two moves.
[0007] Historically, the Jacquard mechanism involved a paper selection card having a pattern of punched holes. The selection card would allow those rods (or hooks) located at a hole to pass through and lift the corresponding warps, whereas the rods would be blocked at the locations without holes. By changing or shifting the selection card after each pass, the weave pattern could be formed.
[0008] This process was mechanically complex and often led to breakdowns and fabric quality problems. The mechanical complexity has been a major obstacle to increasing the efficiency of Jacquard machines. In response, several electrically selected loom latches have been proposed. For example, U.S. Pat. No. 6,073,662 to Herbepin, which is incorporated herein by reference, teaches the use of an electromagnetic device having a coil to control the position of each catch relative to a corresponding hook in a Jacquard selection device. When an electromagnet device is powered, the attached catch is positioned to engage the corresponding hook. The shed is opened by operation of a lifting board. Despite such proposed solutions, electrical and electromagnetic selection devices remain relatively large in comparison to the scale of the weave pattern.
[0009] A refinement of this electrical approach has been the application of piezoelectric elements to Jacquard selection devices. Piezoelectric actuator elements are devices that produce a lateral or longitudinal displacement with a high force capability when an operating voltage is applied. There are many applications where a piezoelectric actuator may be used, such as ultra-precise positioning and the generation/handling of high forces or pressures in static or dynamic situations.
[0010] Actuator configuration can vary greatly depending on application. For example, a flexure strip of piezoelectric material can be used to produce a transverse displacement. Piezoelectrics can also be stacked together to increase the displacement.
[0011] These devices are especially useful for controlling vibration, positioning applications and quick switching. For example, piezoelectric actuators can be designed to produce strokes of several micrometers at ultrasonic (>20 kHz) frequencies.
[0012] The critical specifications for piezoelectric actuators are the displacement, force and operating voltage of the actuator. Other factors to consider are stifffiess, resonant frequency and capacitance. Stiffness is a term used to describe the force needed to achieve a certain deformation of a structure. For piezoelectric actuators, it is the force needed to elongate the device by a certain amount.
[0013] Numerous approaches have been proposed to improve the operation of Jacquard-type weaving machines by incorporating piezoelectric elements. For example, U.S. Pat. No. 5,392,818 to Seiler discloses a needle selector for a Jacquard weaving machine similar to prior art mechanical devices only using piezoelectric transducers to adjust each blocking element. U.S. Pat. No. 6,470,919 to Wardle discloses an individual warp selector wherein a piezoelectric element drives a motor which mechanically moves a rigid heald. U.S. Pat. No. 5,464,046 to McIntyre discloses another individual warp selector wherein a piezoelectric element mechanically slides a warp selector in the longitudinal direction. U.S. Pat. No. 5,647,403 to Willbanks discloses using a piezoelectric element as a mechanical brake on the movement of a Jacquard warp selector. U.K. Patent No. GB 2 276 637 to Seiler and U.S. Pat. No. 5,666,999 to Dewispelaere disclose using piezoelectric elements as controls (locks) on the movement of catches for engaging lifting hooks in an open shed loom arrangement. However, each of these approaches simply uses the piezoelectric element to activate the mechanical elements which select the warp yarns. Because these approaches retain many of the complex mechanical features of the prior art, they exhibit many of the same limitations. For example, the size of these devices is not amenable to weaving high density patterns.
[0014] Therefore, a need exists for a Jacquard selection device which is mechanically reliable, operates at high-speed, has low power consumption, and is small enough to provide for high density warp selection.
[0015] The present invention provides a solution to the problem of providing a high density Jacquard selection device which is high-speed, reliable, and low power.
SUMMARY OF THE INVENTION
[0016] Accordingly, the present invention is an electronic selection card for a Jacquard machine which is high density, compact, and reliable.
[0017] The present invention is a selection device for a Jacquard machine. The device has a parallel array of evenly spaced piezoelectric actuated flexure elements which lie in a plane. Each flexure element in the array has a corresponding hook element connected to one end. A holding bar connects a second end of each flexure element in the array and lies in the plane. An axial rod parallel to the holding bar passes through an axis hole in each hook element, thereby providing a common axis for each hook element to pivot. Each hook element is independently positioned by actuating the piezoelectric in the corresponding flexure element, thereby causing the flexure element to bend out of the plane and forcing the connected hook element to pivot about the common axis.
[0018] Other aspects of the present invention include that the selection device may be an electronic selection card for a Jacquard loom used to weave fabric patterns. The hook elements may be used to select warp yarns from a harness for lifting to form a shed during weaving.
[0019] In a preferred embodiment, the array comprises twenty-four (24) piezoelectric actuated flexure elements and corresponding hook elements spaced within a length of less than 90 mm.
[0020] In another embodiment, each hook element comprises two opposing hooks.
[0021] The present invention will now be described in more complete detail with frequent reference being made to the drawing figures, which are identified below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a more complete understanding of the invention, reference is made to the following description and accompanying drawings, in which:
[0023] FIG. 1 is a front and side view of an exemplary compact selection card in accordance with the teachings of the present invention;
[0024] FIG. 2 is a side view of an exemplary double hook compact selection card in accordance with the teachings of the present invention; and
[0025] FIG. 3 shows comparison views of the closed shed operating cycle for a prior art electric selection device and a piezoelectric selection device in accordance with the teachings of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The present invention is a compact selecting card for use in a Jacquard device; e.g. a loom. The selecting card comprises an array of selecting hooks which are individually positioned by piezoelectric actuators. Such a card provides many advantages over prior art electronic selection cards. For example, the present card exhibits improved operating speed and positional control, lower power consumption, and increased lifetime.
[0027] FIG. 1 is a front and side view of an exemplary compact selection card in accordance with the teachings of the present invention. The selection card has a parallel array of evenly spaced piezoelectric actuated flexure elements 20 which lie in a plane. Each flexure element in the array has a corresponding hook element 40 connected to one end. A holding bar 10 connects the other end of each flexure element 20 in the array and lies in the plane. An axial rod 30 parallel to the holding bar passes through an axis hole in each hook element 40 , thereby providing a common axis for each hook element to pivot. The holding bar 10 and axial rod 30 combine to create a no-play assembly for the flexure elements 20 . This allows the piezoelectric elements to supply all their force and control to the attached hooks 40 . Each hook element 40 is independently positioned by actuating the piezoelectric in the corresponding flexure element 20 , thereby causing the flexure element to bend out of the plane and forcing the connected hook element to pivot about the common axis.
[0028] The present selection device is suitable for use in a Jacquard loom used to weave fabric patterns. The hook elements may be used to select warp yarns from a harness for lifting to form a shed during weaving. This arrangement of flexure elements allows for a selection hook density such that each harness in a loom can be driven independent from one another.
[0029] In a preferred embodiment, the array comprises twenty-four (24) piezoelectric actuated flexure elements and corresponding hook elements spaced within a length of less than 90 mm. These hooks correspond to the yarns in a 24 warp yarn harness. This hook density is sufficient for each harness on a loom to be driven independently. For control of fewer than 24 yarns, the harness is simply not threaded for those yarns. Conversely, to control more than 24 yarns, multiple selection cards and harnesses can be used.
[0030] FIG. 2 is a side view of another embodiment of the invention in which each hook element comprises two opposing hooks. As in the single hook embodiment, this double hook selection card has a parallel array of evenly spaced piezoelectric actuated flexure elements 20 which lie in a plane. A holding bar 10 connects one end of each flexure element 20 in the array and lies in the plane. Attached to the other end of each flexure element are a pair of hook elements 40 . Axial rods 30 parallel to the holding bar pass through an axis hole in each hook of the double hook elements 40 , thereby providing common axes for the hook elements to pivot. The holding bar 10 and axial rods 30 combine to create a no-play assembly for the flexure elements 20 . This allows the piezoelectric elements to supply all their force and control to the attached hooks 40 . Each pair of hooks are independently positioned by actuating the piezoelectric in the corresponding flexure element 20 , thereby causing the flexure element to bend out of the plane and forcing the connected hook elements to pivot about the common axis. Because of the double hook configuration, a preloaded mechanism 50 such as a spring is needed to bias the hooks back into their neutral in plane position.
[0031] Both the single hook and double hook embodiments of the present selection card can be used in conjunction with various lifting devices in both closed shed and open shed configurations.
[0032] FIG. 3 shows comparison views of the operating cycle of a closed shed configuration for: 3 A) a prior art electric selection device and 3 B) a piezoelectric selection device in accordance with the teachings of the present invention.
[0033] The prior art electric devices in the closed shed configuration commonly use two plates moving in a 4 step cycle. Typically, the upper plate 80 acts as the lifting device and contains the selection device, while the lower plate positions the rods of the harness. In step S 1 , the upper plate 80 (or top lifting board) is in a raised position and the lower plate 70 is in a lowered position, thereby forming a wide separation between the plates. The upper plate hook element is not engaged with the hooked rod (or heald) 60 . Note the shown upper plate hook corresponds to one of the hooks in a selection device while the hooked rod corresponds to one of the warps in the harness. The hooked rod passes through the lower plate and connects, typically through an eyelet, to a warp yarn 90 . The hooked rod 60 is biased by a spring or weight 100 such that the rod and the connected warp yarn are pulled down as shown when the lower plate is in the lowered position and the hook is not engaged. This results in the connected yarn being in a lowered position. As shown in step S 2 , the plates are then moved towards each other. In this configuration, the upper plate is in a lowered position and the lower plate is in a raised position, thereby forming a narrow separation between the plates. By moving the lower plate from the lowered position to the raised position the hooked rod is also raised such that the connected yarn is in a flat or neutral position. In step S 3 , the upper plate hook is positioned by the electric mechanism to engage the hooked rod. Typically, the electrical mechanism is an electromagnetic coil which is activated to switch the hook between positions. The upper plate and lower plate are then moved apart in step S 4 (to their respective positions in step S 1 ). Because the upper plate hook is engaged with the hooked rod, when the upper plate moves to the raised position the hooked rod and connected yarn are pulled up as well. As shown, the connected yarn is pulled into a raised position above the neutral position. In this manner, each warp yarn in the harness can be controlled by engaging or not engaging its connected rod with the corresponding hook element in the selection device.
[0034] For the piezoelectric device shown in 3 B, the electrical mechanism is replaced by the holding bar 10 , flexure elements 20 , and hooking elements 40 of the present selection card. This piezoelectric device similarly uses two plates moving in the same 4 step cycle as the prior art electric devices. For this type of design, the present selection cards are attached in position to the upper plate (top lifting board). The harness is positioned by the lower plate such that the rods in the harness can be engaged by the selection card hooks.
[0035] Another aspect of the invention is a feedback mechanism which can be integrated into the electrical control circuitry for the piezoelectric elements to determine the current position of the hook. In this manner, the proper functioning of each of the hook elements in the selection card can be actively monitored.
[0036] The present invention is applicable for use in many types of Jacquard equipment or any unit where binary positioning by mechanical components is required. As discussed herein, the present device may be used, in a Jacquard machine, to activate the position of each harness. In other applications, the device could be used to activate intermediary components linking each hook to parts that require setting in a binary position.
[0037] Modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the present invention. The claims to follow should be construed to cover such situations.
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A compact electronic selection card applicable for use in Jacquard equipment, having a high-density array of selecting hooks which are individually positioned by piezoelectric actuator elements. Each piezoelectric element directly controls a selecting hook for engaging a corresponding hooked rod connected to a warp yarn. The engaged rods are then lifted to form the shed. Because each element directly positions the hook rather than indirectly controlling a positioning mechanism, the selection card is mechanically simple and compact.
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BACKGROUND OF THE INVENTION
The field of the present invention is brake devices and, more particularly, brake devices for motorcycles employing cooling mechanisms.
In rear suspension systems for motorcycles, rear swing arms are commonly employed which are forked to either side of a rear wheel to provide support at either end of a rear axle. In such circumstances, a rear brake is easily mounted to one side of the rear wheel where it may get adequate cooling from airflow passing thereby. However, in cantilever type rear swing arms where the rear axle is cantilevered from a single rearwardly extending arm, the geometry is such that the rear brake is generally located between the rear swing arm and the wheel hub with the wheel hub being concaved. Consequently, inadequate air flow may be experienced for cooling of the brake. Under such circumstances, and particularly when the motorcycle is being ridden very hard such as in competition, overheating can be experienced.
SUMMARY OF THE INVENTION
The present invention is directed to a braking system associated with a cantilever type rear swing arm which provides adequate cooling to the rear brake. To accomplish the foregoing, a passage is provided through the rear swing arm from the outer wall thereof to a location adjacent the brake.
One means by which the foregoing may be accomplished is to provide an inlet on one outer sidewall of the rear swing arm and an outlet on an inner sidewall of the swing arm adjacent the brake. In addition, the rear swing arm may be hollow and a distinct passage between the inlet and the outlet need not be defined. For strength and support purposes, such an arrangement may include a thick inner sidewall of the rear swing arm and a thinner outer sidewall, the rear swing arm being defined as a box section.
Accordingly, it is an object of the present invention to provide an improved braking system for motorcycles. Other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a motorcycle employing the present invention.
FIG. 2 is a cross-sectional plan view of the rear swing arm and axle assembly of the motorcycle in FIG. 1.
FIG. 3 is a cross-sectional side view taken through the rear swing arm of the motorcycle of FIG. 1.
FIG. 4 is an oblique view of a rear swing arm of the present invention.
FIG. 5 is a cross-sectional view taken perpendicular to the fore and aft orientation of the vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning in detail to the drawings, a motorcycle 1 is illustrated as including a frame 2, a head pipe 3, a front wheel 4 supported on a front fork 5 and controlled by handlebars 6. Mounted on the frame 2 is an engine 7 having a drive sprocket 7a. On top of the frame 2 is a fuel tank 8 and seat 9. A cantilever type rear swing arm 10 supports a rear wheel 11 and is suspended by means of a cushion 12. A front fairing 13 is also illustrated on the motorcycle. An exhaust pipe 14 extends rearwardly from the engine 7.
Rear swing arm 10 is pivotally mounted at the end of frame members 2a. A front portion 10a of the rear fork 10 extends to two pivot hubs 10b spaced apart to adjacent the frame members 2a. A transverse portion 10c of the rear fork extends from one of the two front end portions to join with the main body of the swing arm to one side of the rear wheel 11. The main body 10d of the rear fork 10 then extends rearwardly to the rear portion 10e thereof. At the end of the rear portion 10e is a circular mounting portion 10f defining a support 10g for the axle assembly. In extending rearwardly, the rear fork 10 includes a concave portion 10h designed to avoid the rear wheel. This concave portion 10h defines an inner wall sidewall of the swing arm 10. An outer vertical sidewall 10i is spaced from and runs generally parallel to the inner wall 10h from the concavity rearward. As can be seen in FIG. 5, the thickness of the wall 10h is greater than that of the wall 10i for structural considerations. An opening 10j to the hollow interior S of the rear swing arm 10 is located through the outer wall 10i.
Positioned within the support portion 10g of the rear swing arm 10 is a cylindrical holder 15. The holder 15 is held securely by means of bolts 16 closing a split case portion of the support 10g. Centrically extending through the holder 15 is an axle 17. The axle 17 is rotatably mounted in bearings 18 and 19.
Positioned about an extended portion 17a of the axle shaft 17 is a drive mechanism 20 fixed to the shaft 17 at the extension 17a. An outer member 21 is rotatably mounted relative to the holder 15 about a bearing 22. The outer member 21 includes a sprocket 21a which is the driven sprocket of the chain transmission. It is coupled with the drive sprocket 7a by means of a chain 23.
A hub 24 is located at the other end of the shaft 17 and held in place by a nut 25. The hub 24 mounts the rear wheel 11 by means of nuts 26. The rear wheel 11 includes a concave dish portion 11b extending outwardly to a wheel rim 11d to support a tire 11a. Mounting bases 11c receive the nuts 26. Also mounted to the hub 24 is a brake disc 27. Thus, the disc 27 is caused to rotate with the wheel 11.
Fixed relative to the rear swing arm 10 is a brake caliper 28 having brake pads 28a. The brake caliper 28 is mounted by means of an attaching plate 29 having a base portion 29b extending about the rear end portion 10f of the swing arm 10. A connecting portion 29a of the attaching plate 29 is interlocked with the rear swing arm 10, as can best be seen in FIGS. 2 and 3, to prevent rotation thereof.
Looking specifically to the air passage, located through the hole 10j is an air inlet 30 defined by a forwardly facing scoop 31. The air inlet 30 leads to the interior s of the rear swing arm 10. Air outlet 32 is located adjacent the brake to transmit the cooling flow from the inlet 30 to the brake area. Also extending through the hollow interior S of the rear swing arm 10 is the brake hydraulic line 33 to the caliper 28. The brake line 33 passes through a hole 34 in the upper surface of the rear swing arm 10.
Thus, an improved brake system is disclosed having particular applicability to cantilever type rear swing arm systems. While an embodiment of this application is shown and described, many modifications are possible without departing from the inventive concepts herein. Consequently, the invention is not to be limited except by the scope of the appended claims.
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A motorcycle having a cantilevered type rear swing arm including a rear brake between the swing arm and the rear wheel. An air inlet is provided on one side of the other rear swing arm in a thin sidewall. An air outlet through a thick sidewall adjacent the brake allows air passage through the swing arm for cooling of the brake.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine with a built-in driving motor, and more particularly to a sewing machine having an arm in which the driving motor is located.
2. Description of Related Art
Conventionally, a frame of a sewing machine includes a horizontally extending bed, a pedestal standing on the bed at one end portion thereof, and a cantilever arm having one end supported by the pedestal and having the other end extending parallel to the bed. A motor for driving the sewing machine is an AC servo motor or the like, and it is normally mounted under a table on which the sewing machine is mounted.
A driving force of the motor is transmitted through a belt and a pulley provided outside the arm to a main shaft provided in the arm. A needle bar and a thread take-up lever are driven by the rotation of the main shaft. Further, the driving force of the motor transmitted to the main shaft is transmitted through a cam, a vertical shaft, etc. to a bottom shaft provided in the bed. A feed dog and a loop taker are driven by the rotation of the bottom shaft.
U.S. Pat. No. 4,807,548 discloses a sewing machine having a driving motor located in a central portion of an arm. This sewing machine is very compact since the motor is located in the arm.
However, as the central portion of the arm is protruded in the air and is not supported at a lower portion thereof, the location of the motor, which is relatively heavy in the central portion of the arm, causes weight unbalance of the sewing machine. Accordingly, vibration is increased when the sewing machine is driven. Furthermore, the strength of the arm and the pedestal must be made large in order to support the motor, thus causing an increase in weight of the sewing machine. Further, the arm is formed from a cylindrical casting. Therefore, when mounting the motor in the central portion of the arm, it is necessary to deeply insert the motor into the arm and fix the motor to the arm using a long screw. Accordingly, the assembly and disassembly operation of the motor with respect to the arm when maintenance or the like is required becomes very troublesome.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a sewing machine with a built-in driving motor which can maintain weight balance and reduce the vibration of the sewing machine when the sewing machine is driven.
Another object of the present invention is to provide a sewing machine with a built-in driving motor which eliminates the necessity of increasing the strength of the arm and the pedestal, thereby reducing the weight of the sewing machine.
To achieve the above objects, a sewing machine according to the present invention comprises: a bed, a pedestal supported by the bed, an arm having one end supported by the pedestal and having an opposite end extending in a horizontal direction, and a motor for driving the sewing machine, the motor being mounted in the one end portion of the arm.
As mentioned above, the end portion of the arm in which the motor is located is supported by the pedestal. Therefore, the location of the relatively heavy motor in the arm does not cause weight unbalance of the sewing machine. Accordingly, the vibration generated in driving the sewing machine is reduced. Furthermore, as the strength of the arm and the pedestal need not be increased, the weight of the sewing machine is reduced. Additionally, as it is unnecessary to deeply insert the motor into the arm, the assembly and disassembly operation of the motor with respect to the arm can be carried out very easily.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will be described in detail with reference to the following figures, wherein:
FIG. 1 is an exploded perspective view of the sewing machine according to a preferred embodiment of the present invention;
FIG. 2A is a schematic elevational view showing an internal structure of the sewing machine;
FIG. 2B is a schematic side view showing the internal structure of the sewing machine; and
FIG. 3 is a vertical sectional view of an end portion of an arm on the side of a pedestal of the sewing machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment will be described in which the present invention is employed in an industrial sewing machine.
Referring to FIGS. 1, 2A and 2B, a frame 2 formed of die-cast aluminum of a sewing machine 3 according to the preferred embodiment is comprised of a bed 70, a pedestal 7 standing on the bed 70 at one end portion thereof, and an arm 4 extending from the pedestal 7 in parallel to the bed 70. Pedestal 7 comprises a left side wall 7a and a right side wall 7b defining an internal hollow 7c. A cover 5 is detachably mounted on an upper open portion of the arm 4. A cylindrical portion 10 is formed at an end portion of the arm 4 supported by the pedestal 7. An AC servo motor is located in the cylindrical portion 10. A plurality of grooves 11 are formed on an outer circumferential surface of the cylindrical portion 10 so as to extend in a longitudinal direction thereof. A cover 6 is detachably mounted outside the cylindrical portion 10. A plurality of grooves 14 are formed on an outer surface of the cover 6.
A rear wall portion 15 of the arm 4 opposed to the cylindrical portion 10 is slightly expanded rearwardly to define a small space 16 between the rear wall portion 15 and the cylindrical portion 10. A front wall portion 17 of the arm 4 is formed with two supporting walls 20 and 21 extending toward another rear wall portion 18 of the arm 4. There are defined two recesses 22 and 23 between a rear end of the supporting wall 20 and the rear wall portion 18 and between a rear end of the supporting wall 21 and the rear wall portion 18, respectively. A needle bar 30 having a needle 71 is vertically movably supported in a head 8 formed at the other end of the arm 4. A thread sweeping solenoid 9 is mounted on the outside of the head 8.
A main shaft 12 rotatably supported by the supporting wall 21 is provided between the AC servo motor 1 and the needle bar 30. The main shaft 12 and an output shaft 25 of the AC servo motor 1 are coaxially connected with each other by a coupling 29 rotatably supported by the supporting wall 20. A timing pulley 26 is fixed to an outer circumference of the coupling 29. A fan 27 for introducing cooling air into the AC servo motor is mounted on the timing pulley 26. A driving force of the AC servo motor 1 is transmitted through the main shaft -2 to a known mechanism for vertically moving the needle bar 30. As a result, the needle bar 30 is vertically moved.
A bottom shaft 31 is rotatably supported in the bed 70 of the frame 2. A timing pulley 32 is fixed on the bottom shaft 31 at an end portion thereof supported by pedestal 7. A timing belt 33 is wound around both the timing pulley 26 fixed to the coupling 2 and the timing pulley 32 fixed to the bottom shaft 31. The driving force of the AC servo motor 1 is also transmitted through the timing pulley 26, the timing belt 33 and the timing pulley 32 to the bottom shaft 31. The rotation of the bottom shaft 31 is transmitted to a feed rock shaft 35 and a loop taker shaft 36 provided in the bed 70. As a result, a feed dog 49 and a loop taker (not shown) are driven.
A mounting structure of the AC servo motor 1 will now be described in detail with reference to FIG. 3. The AC servo motor 1 is inserted into an internal accommodating space 57 of the cylindrical portion 10 from a right end thereof, cylindrical portion 10 and its internal space 57 comprising means for accommodating the motor, and is fixed to the cylindrical portion 10 by a screw 49. Accommodating space 57 is defined across an extension line D of right pedestal side wall 7b. The means for accommodating the motor further includes a frame E extending in a horizontal direction from a top portion of right pedestal side wall 7b, frame E supporting the motor. The output shaft 25 of the AC servo motor projects in opposite directions from the right and left ends of the cylindrical portion 10. The coupling 29 is a cylindrical member composed of a thick-walled portion 29a and a thin-walled portion 29b. The thick-walled portion 29a is formed with two tapped holes 40 and 41. The main shaft 12 and the output shaft 25 both inserted into the coupling 29 are coaxially connected and fixed together by two screws 42 and 43 threadedly engaged with the tapped holes 40 and 41, respectively. The thin-walled portion 29b is rotatably supported through a bearing 45 to the supporting wall 20, and extends rightwardly through the supporting wall 20 between the outer circumferential surface of the output shaft 25 and the inner circumferential surface of the timing pulley 26. The timing pulley 26 is composed of a body portion around which the timing belt 33 is wound and a fixing portion extending from the body portion toward the supporting wall 20. The fixing portion is provided with a tapped hole 46. The timing pulley 26 is fixedly connected to the coupling 29 by a screw 47 threadedly engaged with the tapped hole 46. That is, although the timing pulley 26 is fixed to the coupling 29, the former is not directly connected to the output shaft 25.
In the case of removing the AC servo motor 1 from the sewing machine 3 for the purpose of maintenance or the like, the screw 43 fixing the output shaft 25 to the coupling 29 is loosened to draw the output shaft 25 rightwardly in FIG. 3. As a result, the output shaft 25 of the AC servo motor 1 is separated from the coupling 29. However, the timing pulley 26 remains fixed to the coupling 29. When mounting the AC servo motor 1 to the sewing machine 3, the same operation is carried out in the reverse order.
A housing 58 of the AC servo motor 1 is comprised of a cylindrical body 59 and a pair of right and left brackets 51 mounted on opposite ends of the cylindrical body 59 by means of screws 50. A pair of ball bearings 52 are provided in the brackets 51, respectively. The output shaft 25 is rotatably supported through the ball bearings 52 to the housing 58. A stator 53 is mounted on the inner circumferential surface of the cylindrical body 59, and a rotor 54 is mounted on the output shaft 25 at a portion thereof opposed to the stator 53.
Two elastic members 55 and 66 having a large-diameter cylindrical shape are interposed between the brackets 51 of the housing 58 and the cylindrical portion 10 of the frame 2. Another elastic member 67 having a small-diameter cylindrical shape is interposed between the right bracket 51 of the housing 58 and a screw 49 threadedly engaged with the cylindrical portion 10 through the right bracket 51. An assembly error between the main shaft 12 and the output shaft 25 in connecting the main shaft 12 through the coupling 29 to the output shaft 25 is absorbed by the operation of the elastic members 55, 66 and 67. Accordingly, the concentricity and the straightness between the main shaft 12 and the output shaft 25 are ensured.
A magnetic drum 68 is fixedly engaged with the right end of the output shaft 25 of the AC servo motor 1. A rotation sensor 69 and a pole sensor 60 are provided on an outer surface of the right bracket 51 of the AC servo motor 1 at a portion thereof opposed to the magnetic drum 68. A rotating member 61 is further mounted on the right end of the output shaft 25. A permanent magnet 62 is mounted on an inner surface of the rotating member 61. A needle position sensor 63 is provided on the right bracket 51 so as to be opposed to the permanent magnet 62.
In the sewing machine 3 having the above construction according to the preferred embodiment, when the AC servo motor 1 is energized, the output shaft 25 is rotated. As the output shaft 25 and the main shaft 12 are fixedly connected together by the coupling 29, and the timing pulley 26 is fixedly connected to the coupling 29, all of the main shaft 12, the coupling 29 and the timing pulley 26 are integrally rotated with the output shaft 25. Accordingly, a driving force of the AC servo motor 1 is transmitted to the main shaft 12, and is also transmitted through the timing belt 33 to the bottom shaft 31.
The sewing machine 3 of the preferred embodiment has the following advantages.
As the AC servo motor 1 is located in the end portion of the arm 4 which is supported by the pedestal 7, the upper structure of the sewing machine 3 is well balanced to thereby suppress the generation of vibration in the sewing operation.
As the AC servo motor 1 is located not in the central portion of the arm 4 distant from the pedestal 7 but in the end portion of the arm 4 supported by the pedestal 7, it is unnecessary to excessively increase a strength of the arm 4 and the pedestal 7. Thus, the weight of the arm 4 and the pedestal 7 can be reduced.
As the output shaft 25 of the AC servo motor 1 is coaxially connected to the main shaft 12 by the coupling 29, a loss of transmission of the driving force of the AC servo motor 1 can be reduced.
If the AC servo motor 1 is located in the central portion of the arm 4, the outer wall of the arm 4 becomes hot as a result of heat generation from the AC servo motor 1, thus causing a burn on an operator. In contrast, according to the preferred embodiment, as the AC servo motor 1 is located at a position distant from a sewing position of the operator, there is no possibility of such a burn.
As the AC servo motor 1 is located not in the central portion of the ar 4 but in the end portion of the arm 4, the operation of assembly and disassembly can be easily carried out to thereby make the maintenance speedy.
The timing pulley 26 is not directly connected to the output shaft 25 of the AC servo motor 1, but is fixed to the coupling 29. Accordingly, when separating the output shaft 25 of the AC servo motor 1 from the coupling 29 for the purpose of maintenance or the like, it is unnecessary to remove the timing pulley 26 and the timing belt 33. Accordingly, in mounting the AC servo motor 1 into the sewing machine 3, readjustment of the timing between the main shaft 12 and the bottom shaft 31 is not necessary. That is, readjustment of the operation timing between the needle bar 30 and the feed dog 49 is not necessary, thereby greatly improving an operation efficiency of assembly and disassembly.
As the assembly error between the main shaft 12 and the output shaft 25 is absorbed by the operation of the elastic members 55, 66 and 67, the concentricity and the straightness between the main shaft 12 and the output shaft 25 can be easily ensured without the necessity of advanced manufacturing techniques. Accordingly, it is possible to prevent the generation of stress, seizure, vibration and abnormal load during the operation of the sewing machine 3.
Although the main shaft 12 and the bottom shaft 31 are connected to one another by the timing belt 33 in the above preferred embodiment, a vertical shaft or the like may be used for the connection. Further, although the fan 27 is employed for cooling the AC servo motor 1 in the above preferred embodiment, a lubricating oil may be used for cooling the AC servo motor 1. Further, the AC servo motor 1 for driving the sewing machine 3 may be replaced by any other different type motor such as a DC servo motor.
While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A sewing machine includes a bed, a pedestal supported by the bed and an arm extending generally parallel to the bed. One end of the arm is supported by the pedestal, this end having a driving motor located therein. The location of the driving motor suppresses vibration created when the sewing machine is operated and facilitates access thereto.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/821,867 filed on Mar. 30, 2001. The disclosure of the above application is incorporated herein by reference.
STATEMENT OF GOVERNMENTAL SUPPORT
[0002] This invention was made with Government support under Award No. DE-FG04-86NE3796 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.
FIELD OF THE INVENTION
[0003] The present invention generally relates to an apparatus for traversing obstacles and, more particularly, to an apparatus for traversing obstacles having an elongated, flexible body, and a drive track propulsion system.
BACKGROUND OF THE INVENTION
[0004] Robotic vehicles are often used to navigate or traverse varying terrain. As is well known, wheeled robotic vehicles, both large and small, are particularly well adapted for travel over relatively smooth terrain, such as roads and smooth floors. However, it is often necessary for robots to traverse terrain that is not smooth, such as stairs or curbs. Moreover, it is often necessary for robots to traverse terrain that may pose a danger to humans, such as those situations presenting an environmental risk, military risk, or the like. Often robotic devices are useless in these dangerous situations because of their inability to successfully and reliably traverse any severely broken and/or fractured ground that they may encounter. Attempts have been made to overcome the numerous disadvantages of wheeled robotic vehicles in these situations by simply increasing the diameter of the wheels or adding tank crawler tracks to increase the ability of the robotic device to traverse large objects or spans. However, these solutions include additional disadvantages, such as increasing the overall size of the vehicle, which may inhibit the robot's ability to pass through small openings.
[0005] Furthermore, many robots suffer from being rendered immobile as a result of a rollover or other situation that prevents contact of their propulsion member(s) on the ground surface. That is, should a wheeled robot encounter a grade sufficient to roll it on its side, the wheels are no longer capable of propelling the robot. In terrains that pose a risk to humans, such rollovers may render the robot unrecoverable.
[0006] Accordingly, there exists a need in the relevant art to provide an apparatus capable of traversing severely broken and/or fractured ground. Further, there exists a need in the relevant art to provide an apparatus capable of traversing severely broken and/or fractured ground without unduly limiting the ability to pass through small openings. Still further, there exists a need in the relevant art to provide an apparatus capable of engaging its environment at any point about its periphery to minimize the possibility of the apparatus becoming immobile. Furthermore, there exists a need in the relevant art to provide an apparatus for traversing obstacles that overcomes the disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0007] According to the principles of the present invention, an apparatus for traversing obstacles having an advantageous design is provided. The apparatus includes an elongated, round, flexible body that includes a plurality of drive track assemblies. The plurality of drive track assemblies cooperate to provide forward propulsion wherever a propulsion member is in contact with any feature of the environment, regardless of how many or which ones of the plurality of drive track assemblies make contact with such environmental feature.
[0008] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0010] [0010]FIG. 1 is a perspective view illustrating an apparatus for traversing obstacles according to a first embodiment of the present invention;
[0011] [0011]FIG. 2 is a side view illustrating the apparatus;
[0012] [0012]FIG. 3 is a front view illustrating the apparatus;
[0013] [0013]FIG. 4 is an enlarged perspective view illustrating the actuation of a joint between two segments of the apparatus;
[0014] [0014]FIG. 5 is a perspective view illustrating an articulating leg mechanism according to the principles of the present invention;
[0015] [0015]FIG. 6 is a perspective view of a universal coupling interconnecting drive shafts of adjacent segments of the apparatus;
[0016] [0016]FIG. 7 is a perspective view of a transmission for transmitting power from the drive shaft to the drive leg mechanism;
[0017] [0017]FIG. 8 is a perspective view of the transmission of FIG. 7 having portions removed for clarity;
[0018] [0018]FIG. 9 is a schematic view illustrating the motion trajectory of the articulating leg mechanism according to the principles of the present invention;
[0019] [0019]FIG. 10 is a perspective view of an articulating joint according to the principles of the present invention; and
[0020] [0020]FIG. 11 is a perspective view illustrating an apparatus for traversing obstacles according to a second embodiment of the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0022] Referring to the drawings, an apparatus 10 for traversing obstacles according to a first embodiment of the present invention is illustrated having a plurality of identical segments 12 . Each of the plurality of segments 12 includes a plurality of articulating leg mechanisms 14 disposed about the periphery of each segment 12 . According to the present embodiment, each of the plurality of segments 12 includes four articulating leg mechanisms 14 evenly spaced at 90° intervals about the periphery of each segment 12 to provide a generally continuous series of propulsion members. However, it is anticipated that any number of articulating leg mechanisms may be used so long as they generally extend around the outer diameter or periphery of each segment 12 . By positioning articulating leg mechanisms 14 continuously about the periphery of segment 12 , apparatus 10 is more likely to engage a feature within the environment to provide reliable locomotion. This ability to engage an environmental feature, whether it be the ground surface, wall protrusion, ceiling cavity, or the like, irrespective of its physical orientation provides apparatus 10 with a reliable means of continued propulsion. Adjacent segments 12 are joined together via an articulating joint 16 and a drive shaft 18 .
[0023] Apparatus 10 may include any number of identical segments 12 connected to each other in a serial fashion. The number of segments 12 required depends on the terrain that must be covered. Moreover, as a result of their identical construction, segments 12 may be easily added, removed, or exchanged with other robots. For illustration and discussion purposes, the figures contained herein comprise nine individual segments 12 .
[0024] Referring in particular to FIGS. 4 and 5, each of the plurality of articulating leg mechanisms 14 includes a leg 20 , a foot 22 , a driven gear 24 , and a drive gear 26 . As can be seen in FIG. 4, articulating leg mechanism 14 includes only one degree of freedom, providing a simplified propulsion system. That is, by having only one degree of freedom per leg, instead of the multiple degrees of freedom like many other legged vehicles, the number of required actuators is reduced, thereby reducing the weight, complexity, and cost of apparatus 10 .
[0025] As best seen in FIG. 3, foot 22 is generally arcuate in shape so as to be generally complimentary to an overall outer shape of apparatus 10 . However, the radius of curvature of each foot 22 is preferably less than the radius of curvature of a circle C (FIG. 3) swept around apparatus 10 and intersects the outermost point of each foot 22 . This arrangement minimizes the potential for sideways rolling of apparatus 10 . However, as described above, should apparatus 10 nonetheless rollover, at least some of articulating leg mechanisms 14 disposed about the periphery of each segment 12 will engage a feature of the environment for continued locomotion.
[0026] The trajectory of foot 22 is determined by the mechanism illustrated in FIG. 5. Specifically, driven gear 24 enmeshingly engages drive gear 26 . Driven gear 24 includes a pivot pin 28 that is operably received within an aperture 30 of leg 20 . Similarly, drive gear 26 includes a cam pin 32 that is operably received within a cam slot 34 of leg 20 . As driven gear 24 rotates in a first direction and thereby drives drive gear 26 in an opposite direction, pivot pin 28 acts within aperture 30 to drive leg 20 in an extending and retracting motion. Simultaneously, cam pin 32 cammingly engages cam slot 34 and drives leg 20 in a sweeping, shoveling, or rotating motion, as illustrated in FIG. 9. Thus, the trajectory of foot 22 generally includes a lowered portion that is in contact with the ground surface for applying a propelling force to move apparatus 10 and a raised portion that is not in contact with the ground surface to allow for forward placement of foot 22 without interfering with the propelling force applied by other feet 22 .
[0027] Apparatus 10 further includes a “head” segment 36 . Head segment 36 is identical to segment 12 ; however, head segment 36 further includes a plurality of sensors 38 (only one shown) and an onboard computer/controller 40 . The plurality of sensors 38 may be used to gather environmental data, surveillance data, or any number of other uses. Onboard computer 40 is used to control the movement of apparatus 10 and to provide a means of controlling and/or communicating with the various systems of apparatus 10 . To this end, onboard computer 40 preferably includes a controller area network (CAN) interface. In operation, onboard computer 40 receives environmental data, surveillance data, or any number of other data from other onboard sensors located throughout apparatus 10 . The data is then carried to onboard computer 40 via a serial CAN bus. The CAN may then be used to provide a control signal to the plurality of articulating leg mechanisms 14 of apparatus 10 . This arrangement reduces the number of electrical wires needed throughout apparatus 10 . The mechanical operation of head segment 36 is identical to that of segments 12 . Therefore, in the interest of brevity, only a single segment 12 will be discussed in detail, except as otherwise noted.
[0028] Apparatus 10 further includes drive shaft 18 . Drive shaft 18 provides input power to each of the plurality of articulating leg mechanisms 14 via a transmission 42 disposed in each segment 12 . Drive shaft 18 is a single drive shaft that kinematically links each segment 12 and, more particularly, each articulating leg mechanism 14 . To this end, drive shaft 18 includes a universal joint 44 (FIG. 6) that allows power transfer independent of the relative orientation of segments 12 . This arrangement enables all articulating leg mechanisms 14 to be driven by a single actuator, generally indicated at 45 , which supplies torque to drive shaft 18 . It should be appreciated that since all articulating leg mechanisms 14 are kinematically linked by single drive shaft 18 , the phase differences between each articulating leg mechanism 14 are fixed. That is, the phase relationship of articulating leg mechanisms 14 , which defines the gait of apparatus 10 , will remain whatever it was when the robot was assembled.
[0029] The use of single actuator 45 for supplying power to all articulating leg mechanisms 14 has numerous advantages. Firstly, actuator 45 can be placed on a specially designed segment (not shown) at the tail end of apparatus 10 in such a way as to minimize the load on articulating leg mechanisms 14 , thus reducing the required size of the actuator. Secondly, multiple actuators weigh more than a single actuator that produce the same amount of power, thus the overall weight of apparatus 10 is reduced by using a single actuator for all articulating leg mechanisms 14 . Thirdly, the use of high energy density power sources, such as a small gasoline engine, might be feasible. The energy density of a small gasoline engine with tank is about one order of magnitude greater than that of a comparable electric motor with lithium-ion battery.
[0030] Referring now to FIGS. 7 and 8, transmission 42 interconnects drive shaft 18 with an input shaft 62 of each articulating leg mechanism 14 of each segment 12 . Transmission 42 includes an inner spur gear 50 that is fixedly coupled to drive shaft 18 for rotation therewith. Inner spur gear 50 meshes with two idler spur gears 52 (only one shown), which each mesh with an outer spur gear 54 (only one shown). Outer spur gear 54 is fixedly coupled to a shaft 56 . Also fixedly coupled to shaft 56 is a worm gear 58 . Worm gear 58 meshes with two worm gears 60 . Each of these four worm gears 60 is fixedly coupled to input shaft 62 of articulating leg mechanism 14 . Input shaft 62 is fixed for rotation with drive gear 26 , which thus drives driven gear 24 and rotates leg 20 and foot 22 through a five-bar geared mechanism as described above to produce the trajectory illustrated in FIG. 9. Alternatively, inner spur gear 50 and outer spur gear 54 may each be replaced with a pulley and belt system for power transfer.
[0031] Adjacent segments 12 of apparatus 10 are connected using articulating joints 16 (FIGS. 4 and 10). Specifically, for discussion purposes, adjacent segments 12 will be referred to as segment 12 a and segment 12 b in FIG. 10 only. Although, it should be appreciated that segments 12 a and 12 b are identical in construction. Each articulating joint 16 comprises two revolute joints, generally indicated as axis A and axis B, whose axes intersect at an intersection point of articulating joint 16 . These two revolute joints are separated by 90° to provide the two degrees of freedom. As best seen in FIG. 10, these two degrees of freedom are each independently controlled with an actuator or pneumatic piston 64 a and 64 b (generally indicated as 64 elsewhere). Each segment 12 a and 12 b include a pair of arm supports 66 extending from end surfaces 68 thereof (FIGS. 7 and 10). The pair of arm supports 66 are pivotally journalled to a floater bracket 70 via a pair of pivot pins 72 . Articulation of joint 16 about axis A is caused when actuator 64 a , which is mounted on segment 12 a , pushes or pulls a bracket 74 a by means of a rotating crank 76 a . Accordingly, this actuation rotates segment 12 a relative to floater bracket 70 about axis A.
[0032] Similarly, articulation of joint 16 about axis B is caused when actuator 64 b , which is mounted on segment 12 b , pushes or pulls a bracket 74 b (located on a backside in FIG. 10) by means of a rotating crank 76 b (located on a backside in FIG. 10). Accordingly, this actuation rotates segment 12 b relative to floater bracket 70 about axis B. Actuators 64 a and 64 b enable apparatus 10 to lift its front end on top of obstacles. This allows apparatus 10 to adjust to the contour of the terrain and overcome obstacles that are orders of magnitude larger than its step height.
[0033] A skin (not shown) may be applied around apparatus 10 to protect all internal parts from moisture or sand. However, in some applications, a skin may not be necessary.
[0034] As best seen in FIGS. 2 and 3, apparatus 10 is illustrated as walking on a flat surface, for a simplified discussion model. However, it should be understood that apparatus 10 is capable of traversing rough terrain. As seen in FIG. 3, the front view of apparatus 10 shows that feet 22 of segment 12 touch the ground at two contact points A and B. This is due to the fact that the radius of curvature of feet 22 is smaller than the overall radius of curvature of apparatus 10 , thereby producing generally flat surfaces extending between the ends of adjacent feet 22 on a single segment 12 (see FIG. 3). This arrangement reduces the tendency of the otherwise cylindrical robot (when all segments are aligned) to roll. However, it should be understood that these contact points may be at any point about the periphery of apparatus 10 . For instance, should apparatus 10 span a fractured ground or fractured pipe, feet 22 of articulating leg mechanism 14 may engage a feature along the ceiling thereof to provide locomotion. Moreover, should apparatus 10 traverse a continuous pipe that is only slightly larger in diameter than apparatus 10 , then all feet 22 disposed about each segment 12 would engage the walls thereof. Thus, each segment 12 may have multiple simultaneous contact points.
[0035] The particular gaits of apparatus 10 will now be described with general reference to FIG. 2, which illustrates a worm-like gait. For purposes of discussion, head segment 36 will be referred to as segment one while the last segment will be referred to as segment nine and the remaining segments numbered consecutively therebetween. Furthermore, the two feet 22 that are contacting the ground at each segment will be referred to as the right and left feet as apparatus 10 faces forward.
[0036] [0036]FIG. 2 illustrates a worm-like gait in that the plurality of articulating leg mechanisms 14 disposed on each segment 12 are synchronized to provide a simultaneous driving motion. That is, accordingly to the worm-like gate, all leg mechanisms 14 on a given segment 12 are in phase with the other leg mechanisms 14 on that given segment 12 . However, adjacent segments 12 are out of phase with each other. For example, to achieve a worm-like gait, the left and right feet of segment one would be in a pre-driving position, the left and right feet of segment two would be in a driving position in contact with the ground surface, and the left and right feet of segment three would be in a post-driving position (see FIG. 2). Such a worm-like gait is particularly useful for burrowing and/or tunneling into soil.
[0037] Alternatively, an alternating tripod gait may be used and is particularly useful for traversing an above-ground surface. According to this alternating tripod gait, the right foot of segments one and seven, and the left foot of segment four all touch the ground simultaneously in generally a triangular pattern. The left foot of segments two and eight, and the right foot of segment five will be the next to touch the ground, and so forth. Accordingly, it should be appreciated that unlike the aforementioned worm-like gait, each articulating leg mechanism 14 is 180° out of phase with the adjacent leg mechanism of the same segment. This arrangement provides a very stable tripod support structure.
[0038] It should be appreciated that the particular gait employed depends, in part, on the terrain encountered. It is anticipated that onboard computer 40 and articulating leg mechanism 14 of apparatus 10 could be adapted to change the gait of apparatus 10 in accordance with the environmental conditions experienced.
[0039] Turning now to FIG. 11, an apparatus 110 for traversing obstacles according to a second embodiment of the present invention is illustrated having a plurality of identical segments 112 . It should be appreciated that apparatus 110 is similar in construction to apparatus 10 . Therefore, in the interest of brevity, only those areas that differ will be discussed in detail herein.
[0040] Each of the plurality of segments 112 includes a plurality of drive track assemblies 114 disposed about the periphery of each segment 112 . Preferably, drive track assemblies 114 are arranged in pairs on each of the four sides of apparatus 110 . However, it should be understood that a single drive track assembly may be used on each of the sides of apparatus 110 . Specifically, according to the present embodiment, each of the plurality of segments 112 includes four pairs of drive track assemblies 114 evenly spaced at 90° intervals about the periphery of each segment 112 to provide a generally continuous series of propulsion members. By positioning drive track assemblies 114 continuously about the periphery of segment 112 , apparatus 110 is more likely to engage a feature within the environment to provide reliable locomotion. This ability to engage an environmental feature, whether it is the ground surface, wall protrusion, ceiling cavity, or the like, irrespective of its physical orientation provides apparatus 110 with a reliable means of continued propulsion. Adjacent segments 112 are joined together via articulating joint 16 and drive shaft 18 .
[0041] Apparatus 110 may include any number of identical segments 112 connected to each other in a serial fashion. The number of segments 112 required depends on the terrain that must be covered. Moreover, as a result of their identical construction, segments 112 may be easily added, removed, or exchanged with other robots. For illustration and discussion purposes, the figures contained herein comprise nine individual segments 112 .
[0042] Still referring to FIG. 11, a transmission 142 interconnects drive shaft 18 with each drive track assembly 114 of each segment 12 . Transmission 142 is similar to transmission 42 and includes a worm gear 158 driven in response to drive shaft 18 . Worm gear 158 meshes with each drive track assembly 114 in an identical arrangement. Therefore, only one complete transmission system will be described. Worm gear 158 meshes with a first spur gear 170 , which in turn meshes with a second spur gear 172 . Second spur gear 172 meshes with a third spur gear 174 . Third spur gear 174 is fixed to a track drive shaft 176 to drive track drive shaft 176 in response to rotation of third spur gear 174 . Track drive shaft 176 preferably extends to both sides of third spur gear 174 and is fixed to a pair of driven gears 178 for rotation with track drive shaft 176 . Each of the pair of driven gears 178 engages a corresponding rack 180 disposed along an inner surface of a flexible track member 182 . Flexible track member 182 includes engaging treads 184 disposed along an outer surface thereof for engaging an environmental feature. Flexible track members 182 are driven around driven gear 178 and an alignment gear 184 disposed at an opposing end of track member 182 . It should be understood that alignment gear 184 is not separately driven, but instead rotates in response to the driving of track member 182 . Accordingly, each of the pair of track members 182 , which are disposed on each side of apparatus 110 , are driven by drive shaft 18 to ensure proper and reliable locomotion.
[0043] Preferably, the four pairs of drive track assemblies 114 disposed on each segment 112 are driven continuously such that if apparatus 110 rolls over, it can continue to be driven. However, it is anticipated that each pair of drive track assemblies 114 may be independently actuated to enable only a selective pair of drive track assemblies 114 to be used at any one time. This would enable power consumption to be reduced in applications requiring onboard power storage and prolonged operation. To this end, computer/controller 40 and at least one of the plurality of sensors 38 may be used to determine orientation of apparatus 110 and output a control signal. In response to this control signal, an engagement mechanism can be actuated to disengage first spur gear 170 from worm gear 158 or second spur gear 172 from first spur gear 170 . The engagement mechanism may be a solenoid operated actuator capable of pivoting first spur gear 170 or second spur gear 172 out of engagement to enable track members 182 to rotate freely so as not to inhibit locomotion. It should be understood that other engagement and/or clutching devices may be used.
[0044] Accordingly, the apparatus of the present invention may find utility in a wide variety of applications. By way of non-limiting example, apparatus 10 , 110 may be used for fully autonomous search for survivors of earthquakes underneath the rubble of collapsed buildings; military applications in very rugged terrain; mining and autonomous search for other natural resources in terrain that is not accessible to humans (i.e., jungles, mountains, etc.); autonomous burrowing in soft soil; monitoring potential underground radiation leakage of buried radioactive waste; nuclear disaster cleanup (e.g., Chernobyl) and sample retrieval; or research platform for studying many-legged locomotion. An additional benefit of using a plurality of pairs of drive track assemblies is the speed at which apparatus 110 can be propelled and the simple and reliable construction thereof.
[0045] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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An apparatus for traversing obstacles having an elongated, round, flexible body that includes a plurality of drive track assemblies. The plurality of drive track assemblies cooperate to provide forward propulsion wherever a propulsion member is in contact with any feature of the environment, regardless of how many or which ones of the plurality of drive track assemblies make contact with such environmental feature.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to, and claims the benefit of the filing date of, co-pending U.S. Provisional Patent Application Ser. No. 60/785,195 entitled “FLEXIBLE CAGE SPINAL IMPLANT,” filed Mar. 23, 2006, the entire contents of which are incorporated herein by reference for all purposes. This application also relates to co-pending U.S. Provisional Application 60/825,089, entitled “OFFSET RADIUS LORDOSIS,” filed Sep. 8, 2006, and to U.S. patent application Ser. No. ______, entitled “INSTRUMENTS FOR DELIVERING SPINAL IMPLANTS” filed concurrently herewith, and to U.S. application Ser. No. 11/303,138, entitled “THREE COLUMN SUPPORT DYNAMIC STABILIZATION SYSTEM AND METHOD OF USE,” filed Dec. 16, 2005, the contents of which are incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This disclosure relates to systems and methods for treating diseases of human spines, and more particularly, to interbody implant devices.
[0003] The human spine is a complex structure designed to achieve a myriad of tasks, many of them of a complex kinematic nature. The spinal vertebrae allow the spine to flex in three axes of movement relative to the portion of the spine in motion. These axes include the horizontal (e.g., bending either forward/anterior or aft/posterior), roll (e.g., lateral bending to either left or right side) and rotation (e.g., twisting of the shoulders relative to the pelvis).
[0004] The inter-vertebral spacing (between neighboring vertebrae) in a healthy spine is maintained by a compressible and somewhat elastic disc. The disc serves to allow the spine to move about the various axes of rotation and through the various arcs and movements required for normal mobility. The elasticity of the disc maintains spacing between the vertebrae during flexion and lateral bending of the spine, allowing room or clearance during the compressive movement of neighboring vertebrae. In addition, the disc enables relative rotation about the vertical axis of the neighboring vertebrae, allowing for the twisting of the shoulders relative to the hips and pelvis. Clearance between neighboring vertebrae maintained by a healthy disc is also important to enable the nerves from the spinal cord to extend out of the spine, between neighboring vertebrae, without being squeezed or impinged by the vertebrae.
[0005] In situations (e.g., based upon injury or otherwise) where a disc is not functioning properly, the inter-vertebral disc tends to over compress. With the over compression, pressure may be exerted on nerves extending from the spinal cord due to this reduced inter-vertebral spacing. Various other types of nerve problems may also be experienced in the spine, such as exiting nerve root compression in neural foramen, passing nerve root compression, and enervated annulus (i.e., where nerves grow into a cracked/compromised annulus, causing pain every time the disc/annulus is compressed), as examples. Many medical procedures have been devised to alleviate such nerve compression and the pain that results from the nerve pressure. Many of these procedures revolve around attempts to prevent the vertebrae from moving too close to each other by surgically removing an improperly functioning disc and replacing the disc with a lumbar interbody fusion (“LIF”) device. Although prior interbody devices, including LIF cage devices, may be effective at improving patient condition, these LIF cage devices may not provide the range of flexibility and support of a properly functioning disc.
[0006] It would be desirable to improve the flexibility of the LIF cage devices, while maintaining the high strength, durability and reliability, of the LIF cage device. A flexible LIF cage device may better enable a patient move about the various axes of rotation and through the various arcs and movements required for a normal range of mobility.
SUMMARY
[0007] An embodiment of the present invention may comprise a flexibility enabling member on a section of an implant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a more complete understanding of this disclosure reference is now made to the following Detailed Description taken in conjunction with the accompanying drawings, in which:
[0009] FIG. 1 illustrates an oblique view of an embodiment of a flexible spinal implant designed to be inserted into an intervertebral space;
[0010] FIG. 2 illustrates a top view of the flexible spinal implant;
[0011] FIG. 3 illustrates an anterior view of the flexible spinal implant;
[0012] FIG. 4 illustrates a midline cross-sectional view of the flexible spinal implant;
[0013] FIG. 5 illustrates an anterior view of the flexible spinal implant, wherein a force is applied to the top portion of the implant;
[0014] FIG. 6A illustrates a side view of the flexible spinal implant, wherein a force is applied to the anterior portion of the implant;
[0015] FIG. 6B illustrates an alternative side view of the flexible spinal implant, wherein a force is applied to the posterior portion of the implant;
[0016] FIG. 7 illustrates an oblique view of the flexible spinal implant, wherein openings of the implant may be pushed out;
[0017] FIGS. 8A-D illustrate anterior views of some of the various embodiments of the flexible spinal implant;
[0018] FIG. 9 illustrates a sagittal view of the flexible spinal implant, wherein the implant is located between two adjacent vertebrae;
[0019] FIG. 10 illustrates an oblique view of a flexible spinal implant, wherein the implant is being injected with a material;
[0020] FIG. 11A illustrates a sagittal view of the flexible spinal implant, wherein the implant comprises a port for injecting a material; and
[0021] FIG. 11B illustrates a midline section view of the flexible spinal implant, wherein the implant comprises a port for injecting a material.
DETAILED DESCRIPTION
[0022] In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the embodiments described in this disclosure may be practiced without such specific details. In other instances, well-known elements may have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail. Additionally, for the most part, details concerning well known features and elements may have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the understanding of persons of ordinary skill in the relevant art.
An Illustrative Embodiment
[0023] Turning now to the drawings, FIG. 1 shows an oblique view of an illustrative embodiment of a flexible spinal implant 100 configured according to at least a portion of the subject matter of the present invention and designed to be inserted into an intervertebral space. The flexible spinal implant 100 may have multiple flexural components 102 provided in an anterior surface of the implant 100 . The flexible spinal implant 100 may also have multiple flexural components 104 provided in a posterior surface of the implant 100 . These flexural components 102 and 104 may comprise empty space (e.g., voids, apertures, cavities, or no material) or they may be filled with a material having a lower modulus of elasticity than a surrounding portion of the implant 100 . The flexural components 104 may be of a similar configuration to the flexural components 102 , or they may be different. Additionally, all of the flexural components 102 , 104 of an anterior or a posterior surface may comprise the same or different configurations. Although, multiple flexural components 102 , 104 are shown in this illustrative embodiment of the present invention, a single flexural component 102 , 104 may exist on an anterior and/or a posterior surface.
[0024] Multiple protrusions 106 may be located on the top surface and/or the bottom surface of the implant 100 . In certain embodiments, these protrusions 106 may help to prevent the implant 100 from substantially moving within the intervertebral space. Although the protrusions 106 may be shown in FIG. 1 as being rectangular shaped, the protrusions 106 may not be limited to this configuration. Any geometric configuration may be used. In addition, an undulating surface may also provide the benefit of fixing the implant 100 in place without necessarily being a distinct protrusion. A single protrusion 106 on the top surface and/or the bottom surface of the implant 100 may also be used. The protrusions 106 may restrain the implant in a relatively fixed location by engaging the opposing surfaces of the endplates of adjacent vertebrae.
[0025] As shown in FIG. 1 , in some embodiments the endpoints 108 of the anterior flexural components 102 may extend to the side surfaces of the implant 100 . The endpoints 110 of the posterior flexural components 104 may be limited to the posterior surface of the implant 100 . Accordingly, in multiple embodiments the anterior flexural components 102 and the posterior flexural components 104 may have a wide range of lengths, widths, and positions. These flexural components 102 and 104 may be configured to alter, reposition, or increase the flexibility of the spinal implant 100 .
[0026] With multiple flexural components 102 on the anterior surface of the implant 100 , the anterior surface of the implant 100 may exhibit an increased ability to resiliently deform when a force is applied to the anterior portion of the implant 100 . Similarly, with multiple flexural components on the posterior surface of the implant 100 , the posterior surface of the implant 100 may also exhibit an increased ability to resiliently deform when a force is applied to the posterior portion of the implant 100 . Accordingly, the implant 100 may be able to provide support within the intervertebral space and also provide a range of flexibility when adjacent vertebrae exert a force on the implant 100 . In certain embodiments, these flexural components 102 and 104 may provide flexibility through less material (e.g., through the use of a cavity, orifice, or a variable thickness of material), which may produce a lower modulus of elasticity, or through a lower modulus material (e.g., through the use of different heat treatments or material processing, or the substitution or addition of a separate material).
[0027] The implant 100 may be manufactured from a variety of biocompatible materials. For example, the implant 100 may be made from biocompatible plastics or metals such as PEEK(poly-ether-ether-ketone), carbon filled PEEK, titanium, or stainless steel, among others. The implant 100 may preferably comprise a sufficient level of strength to at least partially replace a supporting function of an intervertebral disc such that adjacent vertebrae may maintain a desired minimum amount of spacing between opposing surfaces. In some embodiments, the implant 100 may be made of metal, such as cobalt chrome, or titanium. In other embodiments, the implant 100 may be made of ceramic materials or a combination of both metal and ceramic materials, such as oxidized zirconium.
[0028] Turning now to FIG. 2 , this figure illustrates a top view of the flexible spinal implant 100 . Multiple protrusions 106 may be located on the top portion of the implant 100 . As more easily seen in FIG. 2 , in some embodiments the length of the anterior flexural components, which may be defined by the endpoints 108 , may be longer than the length of the posterior flexural components, which may be defined by the endpoints 110 . In this view, the endpoints 108 may be seen as extending to the sides of the implant 100 while the endpoints 110 may be confined to the posterior side surface of the implant 100 . However, the locations and separations of the various endpoints 108 , and 110 may not be limited to this illustrative embodiment.
[0029] The implant 100 may be a substantially oval-shape with a relatively empty center. This oval-shape of the implant 100 may correspond to the shape of the intervertebral disc. This empty center of the implant 100 may be filled with cadaveric bone, autologous bone, bone slurry, bone morphogenic protein (“BMP”) or a similar material. These types of materials may help with tissue growth within the intervertebral space. In some embodiments, openings created by the openings 102 and 104 may further help with tissue growth by allowing the material to seep into the intervertebral space. The illustrative embodiment is shown with a relatively consistent wall thickness. However, depending upon the flexibility configuration, the wall thickness may vary around the perimeter of the implant 100 .
[0030] Referring now to FIG. 3 , this figure illustrates an anterior view of the flexible spinal implant 100 . As stated previously, in certain embodiments the anterior openings 102 may extend further in length than the posterior openings 104 (the posterior openings 104 are seen through the anterior openings 102 in this figure). Accordingly, from an anterior view the endpoints 110 of the posterior openings 104 may be visible because the endpoints 108 of the anterior openings 102 may extend to the side portions of the implant 100 . The anterior openings 102 are shown as being approximately the same number and overall design as the posterior openings 104 as an example of one amongst many embodiments. The protrusions 106 are shown as existing on both the top surface and the bottom surface of the implant 100 in this representation of an exemplary embodiment.
[0031] Turning now to FIG. 4 , this figure shows a midline cross-sectional sagittal view of the flexible spinal implant 100 . As seen in this drawing, in certain embodiments the anterior openings 102 may extend to the side portions of the implant 100 , while the posterior openings 104 may not extend to the side portions of the implant 100 . In addition, the top and bottom surfaces may be substantially parallel in the absence of an applied force to the implant 100 .
[0032] However, some embodiments of the implant (not shown) may be configured such that the top or bottom surfaces may be at an angle to each other in an unloaded condition. These implants may help to restore or recreate a lordosis angle (or other angle) of a human spine. In addition, both of the top and bottom surfaces of the implant may be at an angle relative to a horizontal midline of the implant in an unloaded condition. Alternatively, in certain embodiments (not shown), the top and/or bottom surfaces may be formed from a curved or compound curved surface, instead of the relatively straight line configurations shown in the figure. These implants may also help to restore or recreate a lordosis angle (or other angle) of a human spine. In addition, the contoured top and bottom surfaces (i.e., superior and inferior surfaces) may conform more closely to the concave end plates of the adjacent vertebra. More particularly, the compound curved surfaces may be created by offsetting the radii used to machine the top and bottom (i.e., bearing) surfaces of the implant.
[0033] Further, the cross-sections are shown in FIG. 4 with relatively straight line configurations to aid in simplifying the figures. Although an embodiment of the current invention may be formed as shown, the implant may not be limited to such a configuration. The cross-sections may comprise curved, angular, arcuate, and other configurations able to alter the flexibility of the implant 100 . Additionally, all of the anterior openings 102 and the posterior openings 104 are shown as establishing communication between the interior and the exterior of the implant 100 . As stated previously, in some embodiments, the anterior openings 102 and/or the posterior openings 104 may extend only partially through the walls of the implant 100 .
[0034] Referring now to FIG. 5 , this figure illustrates an anterior view of the flexible spinal implant 100 (shown in broken lines), wherein a force 602 is applied to the top portion of the implant 100 . The force 602 applied to the top portion of the implant 100 may cause the implant 100 to deform or compress into a form of an implant 600 (actual deformation may be exaggerated in this figure for the purposes of illustration). As shown in FIG. 5 , the anterior openings 102 may also compress, enabling the top surface of the implant 600 to move closer to the bottom surface of the implant 600 . The deformation of the implant 600 may enable a larger range of motion for a spinal column in which the implant 600 has been inserted. The deformation is shown as being larger in the central section than at the sides of the implant 600 . This may be due in part to the increased stiffness of the sides of the implant 600 due to a relatively smaller quantity of openings. Although the posterior openings 104 ( FIG. 3 ) may not be visible in FIG. 5 , these openings 104 may exhibit a similar type of compression in response to a force applied to the implant 100 .
[0035] Turning now to FIG. 6A , this figure shows a side view of a spinal implant 700 in which a force 706 has been applied to an anterior portion of the implant 700 . When a force 706 is applied to an implant (e.g., such as illustrated in FIG. 4 ), the anterior openings 102 may compress as described with reference to FIG. 5 . In addition, since the force 706 may be applied primarily to the anterior portion of the implant 700 , the posterior openings 104 may expand. This corresponding behavior between the openings 102 and the openings 104 may be attributed at least in part to the additional flexibility provided by the openings 102 and the openings 104 (the deformation may be exaggerated for the purposes of illustration).
[0036] Accordingly, an area comprising the anterior openings 102 may be defined as a first flex-zone 708 of the implant 700 , while an area comprising the posterior openings 104 may be defined as a second flex-zone 712 of the implant 700 . The first flex-zone 708 may flexibly contract while the second flex-zone 712 may flexibly expand. However, in the event of a relatively uniform force applied to the top surface of the implant 700 , both the first flex-zone 708 and the second flex-zone 712 may be flexibly contracted or expanded, to either the same or differing degrees, depending upon the quantities and configurations of the anterior openings 102 and the posterior openings 104 .
[0037] The middle portion of the implant 700 , which may comprise the side walls, may be defined as a low-flex-zone 710 of the implant 700 . The low-flex-zone 710 may provide a more consistent level of support for two adjacent vertebrae, while the flex-zones 708 and 712 may provide additional flexibility. This additional flexibility may provide an additional range of motion with respect to the two adjacent vertebrae. The low-flex-zone 710 may help to prevent excessive vertical compression and consequential damage to nerve endings passing between the two adjacent vertebrae. The relatively stronger low-flex-zone 710 may also provide a more stable platform for the flex-zones 708 and 712 .
[0038] Referring now to FIG. 6B , this figure illustrates an alternative side view of a flexible spinal implant 750 in which a force 714 has been applied to a posterior portion of the implant 750 . When a force 714 is applied to an implant (e.g., such as illustrated in FIG. 4 ), the posterior openings 104 may contract and the anterior openings 102 may expand. As stated previously, the area comprising the anterior openings 102 and the area comprising the posterior openings 104 may be described as the flex-zones 708 and 712 , respectively. The middle portion of the implant 750 , which may comprise the side walls, may be described as the low-flex-zone 710 of the implant 750 .
[0039] As shown in FIGS. 6A and 6B , there may be at least two degrees of motion for an implant 700 , 750 depending upon the direction and location of the applied force. The motion illustrated in an embodiment of the present invention may allow for more natural movement of a spinal column and may begin to replace at least a portion of the functionality of a collapsed intervertebral disc. Additionally, the openings 102 and 104 may function to control motion during both expansion and contraction of an implant 700 , 750 .
[0040] Turning now to FIG. 7 , this figure shows an oblique view of an embodiment of a flexible spinal implant 800 in which the openings 102 of the implant 800 may be pushed out or removed. In certain embodiments, the implant 800 may have one or more removable members 105 retained within the implant 800 through the use of perforated dividers, interlocking features, friction forces, threaded fasteners, and adhesive forces, among others. The removable members 105 may be detached in response to a force 802 applied to the anterior or posterior portion of the implant 800 . Accordingly, a tool 804 may be utilized to apply a force 802 to the implant 800 and produce an opening 102 , by detaching the removable members.
[0041] This feature may enable a physician to adjust the flexibility of the anterior or posterior portion of a standard or common implant 800 to be adapted to the specific needs of a patient or a specific requirements of a portion of a patient's spine. The removable portions 105 may be removed prior to insertion of the implant 800 within a patient's body. However, there may be situations in which a range of motion of a patient may be adjusted via the removable members 105 after insertion. Additionally, the implant 800 is shown as configured with removable members 105 . However, the flexibility of the implant 800 may be also be adjusted through the insertion of members with appropriate degrees of flexibility into openings 102 . In some embodiments, the distraction height that the implant 800 provides may be increased by placing appropriate inserts into the openings 102 . Consequently, the flexibility of a portion of a standard or common implant 800 may be increased or decreased (i.e., modified) through the removal of removable members 105 and/or insertion of other inserts into the openings 102 .
[0042] Referring now to FIG. 8A , this figure illustrates an anterior view of an embodiment of the flexible spinal implant 902 . In one example amongst many of an embodiment, the implant 902 may comprise a single opening 904 . The opening 904 for example, may be irregularly shaped, symmetrical, or asymmetrical, in order to provide additional flexibility to the anterior portion (for example) of the implant 902 . The overall design configuration for the opening 904 may be determined based upon results from finite element analysis for example.
[0043] Turning now to FIG. 8B , this figure shows an anterior view of another alternative embodiment of the flexible spinal implant 912 . In one example of an embodiment of the present invention, the implant 912 may comprise two corresponding openings 914 . These corresponding openings 914 may provide additional flexibility to the anterior portion (for example) of the implant 912 . As seen in FIG. 8B , the two corresponding openings 914 may be configured to create an interconnecting member 915 located there between. The interconnecting member 915 may provide an additional degree of resiliency for the anterior portion of the implant 912 . While the interconnecting member 915 may be shown as being integral to the anterior portion of the implant 912 , other resilient members such as springs, compressible material, and others may be used to provide the additional degree of resiliency.
[0044] Referring now to FIG. 8C , this figure illustrates an anterior view of another alternative embodiment of the flexible spinal implant 922 . In one illustrative embodiment, the implant 922 may comprise multiple circular or other configurations of openings 924 . As shown in this example, these cylindrical openings 924 may provide additional flexibility to the anterior portion (for example) of the implant 922 . Cylindrical openings 924 may be easily created in the anterior portion of the implant 922 through the use of drills or cores during molding for example. As with the illustrative embodiment discussed along with FIG. 7 , the numbers, sizes, and placements, of the openings 924 may be made in a more common, generic implant according to the requirements of the patient.
[0045] Turning now to FIG. 8D , this figure shows an anterior view of an alternative embodiment of the flexible spinal implant 932 . In one example of an embodiment, the implant 932 may comprise a single oval-shaped opening 934 . The oval-shaped opening 934 may provide additional flexibility to the anterior portion (for example) of the implant 932 . A large relatively smooth opening such as the opening 934 may reduce local areas of stress concentration within the implant 932 .
[0046] Additional embodiments of the anterior portion of an implant 100 are within the scope of this disclosure. This disclosure should not be limited to the embodiments shown in FIGS. 8A-8D . In addition, the embodiments shown in FIGS. 8A-D and other additional alternative embodiments of openings may be applied to the posterior portion or side portions of an implant 100 . The other embodiments may be applied singly, in multiple numbers, or in combinations without limit as long as the flexibility and strength of an implant 100 are maintained at desired levels.
[0047] Referring now to FIG. 9 , this figure illustrates a sagittal view of the flexible spinal implant 100 in which the implant 100 is located between two adjacent vertebrae 1002 and 1004 . As shown in FIG. 9 , the implant 100 may be placed in an intervertebral space. In this position, the flexible spinal implant 100 may function similarly to an intervertebral disc by providing both support and flexibility. Accordingly, anterior openings 102 and posterior openings 104 may provide an appropriate amount of flexibility to the implant 100 .
[0048] Protrusions 106 may help to prevent the implant 100 from significantly moving within the intervertebral space relative to the two adjacent vertebrae 1002 and 1004 . The protrusions 106 may be located on the top and bottom surface of the implant 100 and engaged with the opposing surfaces of the two adjacent vertebrae 1002 and 1004 .
[0049] In certain embodiments the implant 100 may be configured as a dynamic device, such as a partial disc replacement (PDR). The implant 100 may be used to stabilize adjacent vertebrae as the spine moves in various directions. A dynamic stabilization device may be used in conjunction with the implant 100 as part of a three column support dynamic stabilization system as is described in more detail in co-pending U.S. application Ser. No. 11/303,138, entitled “THREE COLUMN SUPPORT DYNAMIC STABILIZATION SYSTEM AND METHOD OF USE,” filed Dec. 16, 2005, and incorporated herein by reference for all purposes.
[0050] Turning now to FIG. 10 , this figure shows an oblique view of a flexible spinal implant 1110 in which the implant 1110 is being injected with a material 1106 . This material 1106 may be injected in situ. In one embodiment, the implant 1110 may have a port 1102 . An insertion tube 1104 may couple to the port 1102 such that a material 1106 may be injected into the interior of the implant 1110 . This material 1106 may be utilized to provide additional support or flexibility, or to enhance tissue growth within the intervertebral space. Accordingly, materials such as cadaveric bone, autologous bone, bone slurry, BMP, or other similar material, may enhance tissue growth within the intervertebral space. In some embodiments, a separate container or walls may be provided to contain the material within the interior of the implant 1110 .
[0051] Referring now to FIG. 11A , this figure illustrates a sagittal view of the flexible spinal implant 1110 in which the implant 1110 comprises the port 1102 for injecting the material 1106 . The port 1102 may be located in any of the anterior openings 102 and the posterior openings 104 , or the port 1102 may be located in an opening configured specifically for the port 1102 . The material 1106 may be injected into the implant 1110 via this port 1102 . The material 1106 may fill the center portion of the implant 1110 as shown in FIG. 11A . In addition, only two ports are shown in FIG. 10 and only one port 1102 is visible in FIG. 11A , however, a single port or a plurality of ports 1102 may be provided in the implant 1110 . Further, although a separate port 1102 may be described for inserting the material 1106 , the material 1106 may be inserted through an existing anterior and/or posterior opening 102 and 104 .
[0052] Turning now to FIG. 11B , this figure shows a midline cross-sectional view of the flexible spinal implant 1110 , in which the implant 1110 comprises a port 1102 for injecting the material 1106 . The material 1106 may be injected into the implant 1110 via this port 1102 . The material 1106 may fill the center portion of the implant 1110 as shown in FIG. 11B . As previously stated with regard to FIG. 4 , in certain embodiments the anterior openings 102 may extend to the side portions of the implant 1110 , while the posterior openings 104 may not extend to the side portions of the implant 1110 . In addition, the top and bottom surfaces may be substantially parallel in the absence of an applied force to the implant 1110 .
[0053] The cross-sections are shown with relatively straight line configurations for the purposes of illustration. The cross-sections may comprise curved, angular, arcuate, and other configurations able to alter the flexibility of the implant 1110 . Additionally, all of the anterior openings 102 and the posterior openings 104 are shown as establishing communication between the interior and the exterior of the implant 1110 . In some embodiments, the anterior openings 102 and/or the posterior openings 104 may extend only partially through the walls of the implant 1110 . The insertion port 1102 may establish communication between the interior and the exterior of the implant 1110 . The insertion port 1102 may further comprise corresponding engagement surfaces for locating an insertion tube 1104 ( FIG. 10 ) in addition to one way valves or devices necessary to facilitate the insertion of material 1106 into the interior of the implant 1110 .
[0054] It is understood that multiple embodiments can take many forms and designs. Accordingly, several variations of these embodiments may be made without departing from the scope of this disclosure. Having thus described specific embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature. A wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure. In some instances, some features may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of embodiments.
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A implant is provided for placement in a space between boney structures. The implant may comprise a flexible section. The flexible section may be either the anterior side or the posterior side of the implant or both, among other sides. The flexible section or sections may comprise one or more orifices, cavities, or low modulus of elasticity materials among others. The flexible section or sections may facilitate a wider range of motion than otherwise possible for a spinal column comprising a Lumbar Interbody Fusion (LIF) device. Additionally, the anterior side comprising a flexible section may have a different modulus of elasticity than the posterior side comprising a flexible section. The difference may facilitate a wider range of responses from the implant to movement generated forces in at least two directions.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to instant messaging. More particularly, the invention relates to a proxy system for instant messages that allows control over session mobility, content, message aggregation, redistribution and filtering, and personal information profiles.
[0002] Instant messaging has gained wide popularity today. Part of the allure is the convenience of being able to communicate with others where communication by telephone would be inappropriate or inconvenient and where communication by e-mail is too slow. Many cellular telephones are equipped with instant messaging capabilities and these telephones are rapidly creating a new form of human interaction.
SUMMARY OF THE INVENTION
[0003] While instant messaging has many advantages, there is still considerable room for improvement. The present invention provides a personal messaging proxy system or proxy component that may be added to a messaging or instant message system. The personal messaging proxy provides a variety of services not found in conventional messaging or instant messaging and presence (IMP) systems. Among these services are session mobility, parental control, message aggregation/redistribution/filtering and personal information profiles for different kinds of devices based on presence and messaging services. The a personal messaging proxy improves upon existing instant messaging systems. The proxy provides a first information port adapted to receive information from at least one information source, and a second information port adapted to supply information to the instant messaging appliance of a user. The proxy is configured to manipulate the information received from said at least one information source in a variety of ways, and to provide the manipulated information to the user in the form of an instant message.
[0004] As will be more fully explained herein, the present invention makes it possible to support a variety of additional features in an instant messaging system. These features include:
Virtual IMP clients; Bidirectional filtering of messages, subscriptions, groups and presence information; Group chaining; IMP session mobility; Parental control; A personal messaging proxy that can be configured for rules which implement user-configurable automatic behavior; A personal messaging proxy that can be controlled by user actions through an interface or through an instant message.
[0012] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. For a more complete understanding of the invention, its objects and advantages, refer to the following specification and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will become more full understood from the detailed description and the accompanying drawings, wherein:
[0014] FIG. 1 is a block diagram illustrating an enterprise proxy for instant messaging and presence with group chaining;
[0015] FIG. 2 is a similar block diagram illustrating a home proxy for instant messaging and presence with group chaining;
[0016] FIG. 3 is a block diagram illustrating how parental control may be implemented using the proxy according to one aspect of the invention;
[0017] FIG. 4 is an object diagram illustrating a presently preferred personal proxy implementation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0019] The personal messaging proxy allows a user to manage and configure instant messaging and presence services and to implement virtual instant messaging and presence devices in a unified way. As illustrated in FIG. 1 , the proxy, shown generally at 10 , is logically positioned as an intermediary between user client software and devices 12 and service provider relays and servers 14 . The proxy may be implemented as a single software entity or a distributed software entity. It can be installed, for example, on a user's home computer, on a gateway, on an active server page (ASP), or in the service provider's network. Thus a collection of personal proxies for an arbitrary number of users could be implemented in one system.
[0020] In general, a person may have a number of devices and each of these devices may have different capabilities and resource constraints. The personal messaging proxy serves as a central resource to manage presence and instant messaging-related information. Examples of such information include, local contact list information, group information, message history for different kinds of devices, and the like. The personal messaging proxy can implement rules to match the incoming information with the capabilities of each of the user's devices. Thus, a user operating a very low end device may only receive basic presence and messaging information, formatted to fit the profiles for this particular low end device. Thus, for example, a contact list containing only the first ten entries might be displayed. In addition, further rules may be implemented to serve as information filters, effectively channeling selected information to predefine instant messaging and presence devices. The filtering operation can be performed in tiers to effect different information message chains, as illustrated in FIG. 1 .
[0021] Referring to FIG. 1 , the proxy 10 may be configured into one or more tiers (two tiers are illustrated here but a greater number is also possible). The upper level tier 18 operates as a subscription account manager with filtering. Information feeds from a plurality of different information sources (source 1 , source 2 , source N) are fed to the subscription account manager. The account manager then utilizes a stored subscription log 20 to filter the information and passes on to the intermediate tier 22 . In the embodiment of FIG. 1 , these intermediate tiers are configured to represent different groups within an enterprise. Each of the intermediate tiers has its own data store 24 where subscription logs are maintained for each of the intermediate tier groups. The intermediate tiers, in turn, filter the incoming information and pass it to the ultimate instant messaging and presence users operating their respective devices 12 .
[0022] Note that the information flow among tiers and the instant messaging and presence users is bidirectional. Thus an instant messaging user can post a message to the intermediate tier group to which the user subscribes. The message posted is then filtered by the middle tier proxy and distributed accordingly, just as it would distribute any other received information. The middle tier proxy can, if required, route information to the upper tier 10 , as illustrated. When the upper tier receives the information routed to it by the middle tier, it parses, filters and distributes that information using the same rules as it would apply to incoming information from the other information sources.
[0023] In a presently preferred embodiment, the intermediate tiers are designed to package information for delivery to the end users according to an instant messaging and presence protocol. Thus in this preferred embodiment, the information flow to the users and the information flow from the users to the higher level tiers is based on an instant messaging and presence protocol. It is possible, however, to configure the communication between upper tier and intermediate tiers to handle other protocols, such as e-mail and multimedia protocols. The proxy 10 is provided with parsing and semantic analysis capability whereby e-mail messages and multimedia messages are parsed and converted into instant messages for consumption by the user's devices 12 . In the embodiment illustrated in FIG. 1 , the upper level tier 10 is also able to parse and extract semantic content from webpages downloaded using the http protocol. It will be appreciated that the proxy 10 can be configured to receive information from essentially any information source, including but not limited to, instant messages, multimedia messages, e-mail, http information, FTP information, and the like.
[0024] Before discussing further implementation details of the proxy, an additional example of the proxy will be discussed in connection with a home network application. In this embodiment the first tier 18 may be configured as a subscription manager with filtering that is deployed on a residential gateway computer. The intermediate tiers 22 may then be configured to represent different aspects of one's personal life (e.g., work, personal, family, school). The middle tier layer may also be implemented on the gateway system, or, if desired, one or more of the middle tier layers can be implemented on other personal computers or laptop computers. Thus, for example, a parent might elect to have his or her work or personal information stored on a personal laptop, while family information and school information might be stored on a networked computer that is accessible family wide. Message flow within the embodiment of FIG. 2 is essentially the same as that of the embodiment of FIG. 1 .
[0025] The personal messaging proxy 10 can give a user a high degree of control over information flow. This is in contrast to current instant messaging systems, which essentially act as simple message delivery conduits. To illustrate some of the power of the proxy concept, FIG. 3 shows how the personal messaging proxy can be implemented to effect parental control over instant messages. Instant messages have become quite popular among young people, and many parents are concerned that their children may be devoting too much time to instant message communication, or may be participating in inappropriate instant messaging.
[0026] To address this, the proxy 10 may be configured to contain a set of parent-controlled subscription filter rules 40 and also parental controlled content filter rules 42 . Proxy 10 would then apply these filter rules when the child user 12 c either wishes to subscribe to an information source or thereafter when the child participates in instant messaging sessions with other users. The instant messaging proxy 10 can be configured to forward all messages or selected messages to a monitoring parent's device 12 p . In this way, a parent can periodically monitor the instant messaging behavior of the child. The parent could configure the system, for example, to forward selected instant messages to the parent's cell phone, or the system could be configured to generate a synthesized message based on messages between the child and other users or other information sources, with the synthesized message being forwarded to the parent. In addition, proxy 10 may have an associated data store or cache 44 that would store a dialogue history of the child's instant messages. The cache might be resident, for example, on a home computer or residential gateway, and could be accessed by the parent periodically to check for inappropriate instant messaging behavior.
Additional Implementation Details of the Proxy
[0027] As illustrated in FIG. 4 , the personal messaging proxy 10 may be viewed as a proxy object that mediates a predefined set of rules 50 and that is configured to perform a predefined set of actions 52 . Examples of these rules and actions have been illustrated in FIG. 4 . The proxy 10 may be configured to handle various different network media, thus allowing messages to be passed to and from a variety of different instant messaging and presence devices. Several examples of such devices have been Illustrated at 12 in FIG. 4 .
Service Rule Management
[0028] The user's preferences regarding messaging behavior across his or her set of communication and information devices can be viewed as rules which prescribe behavior given a set of conditions. The following table illustrates some rule categories as examples.
TABLE I Rule Category Proxy uses rule(s) to . . . Mapping of device Translate user's device usage to status/usage to presence information (i.e., the presence state status of appliances/devices such as on, off, operational, etc.) of devices/appliances. The innovation will describe different presence attributes an appliance can have and also the retrieval procedure of this information. For example, the body of the SIP NOTIFY message can carry application specific presence attributes (i.e., device specific presence attributes such as: VCR: ON, OFF PLAYING, RECORDING, FAST_FORWARD, REWIND, etc. Global IM client Configure IMP client software on each configuration device and manage user attributes in and acct mgmt IMP service provider domains IM session transfer To enable/disable and control properties for IMP session transfer when user is in session on one device and switches to another device. Subscription filter Set filters on IMP group and user subscriptions which will cause un- permitted subscriptions to be blocked. Message filters Set content filters on IMP/SMS/MMS messages, which will cause unwanted content to be blocked. Set source filters on IMP/SMS/MMS message, which will cause messages from unwanted sources to be blocked Auto-prioritization Automatically determine SMS/MMS of messages message priority based on subject, recipient, or other attribute. Auto-message Determine scheduling and frequency control of messages that are automatically generated by devices for other devices or users.
Proxy Actions (Functions)
[0029] In general, the personal messaging proxy can be configured to provide a wide range of different information processing functions, ranging from simple information routing functions to more complex parsing and semantic processing functions. In the case of multimedia, the proxy might also include speech recognition capabilities, to allow human speech to be converted into text for subsequent information processing.
[0030] The following table lists some example functions that the personal messaging proxy can perform.
TABLE II Function Notes push settings to clients on each device used pull content from devices to generate MMS, Virtual client send on demand or scheduled (one time or periodic) IM to virtual device (e.g., send photo to TV Virtual client receive when visual device/camera is attached to TV) single point management of IM settings
[0031] In the past, when a person is participating in an instant messaging session, the person has been essentially locked into one device for that session. It is not heretofore been practical to switch from one device to another while continuing to participate in the session. The personal messaging proxy removes this limitation.
[0032] By referring to FIGS. 1 and 2 , it will be seen that an instant messaging session flows to the end user device 12 through the proxy 10 . by utilizing suitable routing rules, the information messaging session can be transferred from one device to another while the session is in progress. In addition to transferring the session from one device to another, the proxy 10 may also store the session history within a suitable data store or cache so that the session history can be transferred to the new device.
[0033] Proxy 10 can either replay the instant message from a stored log or it may simultaneously fork from the beginning of the session to each active device. The latter option would allow an instant message to be viewed on multiple devices concurrently. The proxy will keep history information of a messaging session and when the user is logged in with a different device, the history information at the proxy will be transferred to the new device, thereby providing a seamless messaging session. Also, based on the capabilities of the device, contact list, group information and other information may also be transferred to the new device.
[0034] In one presently preferred implementation, the transference of an instant messaging session from one device to another can be effected using the SIP/SIMPLE protocol, where a SIP REGISTER method is used to log in, with the proxy with a new device. The SIP PUBLISH method or MESSAGE method would then be used to transfer history or contact list and group information. A user defined header would be used to identify the kind of information contained in the body.
Virtual IMP Clients and Virtual Devices
[0035] The personal messaging proxy may also be used to implement virtual instant messaging clients or virtual devices. In this regard, other devices could be remotely controlled to obtain information from which a message is generated or received on the device's behalf by the proxy. Referring to FIG. 4 , a digital camera, for example, could have a locally stored photo, a battery level indicator, or its location in the home as stored state information. The personal messaging proxy could provide a virtual messaging client for the digital camera. This virtual client could receive messages from the user, such as “send me images 1 and 2,” “send me a list of images,” “send me your location in the house.” The messages are parsed and processed by the virtual client (using rules and actions of the proxy 10 ). The messages are then communicated to the device to perform the request. Note that the messages sent to a particular device would be translated into the operation semantics of the device.
[0036] In addition to allowing a user to send operating commands to a device, the personal messaging proxy can also be used to allow a device to send messages back to the user. As an example, the virtual client for the digital camera could be enabled to automatically send messages when a low battery indication or an image storage full indication are generated. The operating status of a device may be represented as device presence status information.
[0037] In a presently preferred embodiment, the presence status of a device can be configured using the SIP/SIMPLE protocol. The presence status would then be communicated between a user and the proxy using the SIP SUBSCRIPTION/NOTIFY method. When predefined states are detected on the device, the virtual client will automatically generate the associated message and send it to the user.
Security Considerations
[0038] The personal messaging proxy can be used to authenticate a user accessing a device, such as accessing the digital camera in the example above. It is possible to directly authenticate a user with each device, however, the approach requires a potentially large number of secret keys and may be difficult to implement with devices that do not have sophisticated input terminals with which to enter the secret key. As an alternative, the authentication function may be relegated to a secure network with which the users authenticate. Upon authentication, the proxy would be invoked. Thus, in effect, users would authenticate themselves with the proxy and thereafter, the communication session would be assumed secure.
Bidirectional Filtering and Group Chaining
[0039] As discussed in connection with FIGS. 1 and 2 the personal messaging proxy makes it possible to distribute messages according to tiers of message aggregation. Each tier has subscribers and filters. A collection of information sources sends messages to the first tier of groups. The messages are filtered and forwarded to the subscribers, which may represent a second tier of groups. The second tier collects and filters information from the first tier in order to satisfy requirements of the actual subscribers. These requirements might be based on priority, subject of message, message content, date, source, the active device the user is currently working with, or other attributes.
[0040] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. Accordingly, while the present invention has been described in its presently preferred embodiments, it will be understood that the invention is capable of modification without departing from the spirit of the invention as set forth in the appended claims.
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The personal messaging proxy is deployed as a component in a messaging or instant messaging system. The proxy provides information processing and routing services not found in conventional messaging or instant messaging and presence systems. The proxy provides session mobility, parental control, message aggregation, redistribution and filtering. The proxy also maintains personal information profiles for different kinds of devices based on presence and messaging services.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our previously-filed application, Ser. No. 505,619, filed Sept. 13, 1974, now abandoned, and of our previously-filed application, Ser. No. 648,166, filed Jan. 12, 1976 as a continuation in part of said earlier application and entitled, "PROCESS FOR MAKING DRAPERIES" now U.S. Pat. No. 3,996,083.
BACKGROUND OF THE INVENTION
This invention relates to a process of making draperies. More specifically, the present invention relates to the process of making a reinforced heading for draperies in which the steps of premarking, measuring, and some steps of stitching may be eliminated. Still more specifically, this invention relates to a tape applicator whereby a tape of reinforcing material, such as buckrum or Pellon, may be adhesively applied along a perfectly straight line to the lower end of a panel.
BACKGROUND OF THE PRIOR ART
The conventional procedure in manufacturing draperies is to attach, side-by-side, by means of stitching, a sufficent number of vertical widths of material to provide the desired overall widths of the main drapery panel and to finish the bottom edge of the vertical side edges in the form of a hem. Consequently, in common practice, considerable amount of time has been required to lay the widths of drapery material flat on large tables in a process called "tabling" and to make spaced measurements from the top edge of the panel to pin the hem in as the operator works from the side edge of the drapery to the other marginal side edge. A major improvement in these operations has been made by Michael Tuskos in his U.S. Pat. No. 3,438,438, in an operation referred to as "vertical tabling." As described and claimed in this patent, the panels of drapery material were positioned so that the steps of marking, hemming and pressing could be done by the use of a pivotable ironing board at the bottom. Various catch shelves were provided to mark the panels at various levels so as to provide means for the seamstresses to know where the hem should be placed. The improvement disclosed in the Tuskos U.S. Pat. No. 3,738,007, provided for the vertical suspension of the drapery panels so that the materials could be simultaneously marked and trimmed at the bottom by means of a horizontally-moving carriage, containing a scissors and marker device which would simultaneously mark and trim at a selected height therefrom to allow the seamstresses to later make the stitching for the proper hem. Tuskos, however, never realized or taught the use of his tabler for the production of reinforced headings. He was always concerned only with the hem at the bottom of the tabler. Further, other inventors did not appreciate the vertical suspension of the panel from the hem to put in the reinforcing tape for the pleatable heading. Thus, for example, John Benedetto, in U.S. Pat. No. 3,802,609, still disclosed a horizontal tabling method for adhesively securing a reinforcing tape into a drapery panel, pulled over the large horizontal table 10. Our copending application Ser. No. 648,166, filed Jan. 12, 1976, first disclosed the vertical suspension of the drapery panel from the hem end on a vertical tabler and the adhesive application of a strip of reinforcing tape to the bottom portion of said panel. This invention also taught that the portion of the panel to which the tape is applied, may be supported in a horizontal plane on a pivotable ironing board.
SUMMARY OF THE INVENTION
According to this invention, there is provided a means for automatically applying a reinforcing strip of tape to the suspended drapery panel which can be later formed into a reinforced heading. This is accomplished by means of mounting a tape applicator on a carriage mounted means near the bottom of the frame of the tabler. The carriage is mounted so as to move in a perfectly straight line across said frame so as to adhesively apply the strip of reinforcing tape to the drapery panel at the proper position for folding the remaining portion of the panel over itself so as to sandwich the tape therebetween and to form a reinforced heading. By this method, since the tabler contains retractable measuring tapes on the frame members and the suspended panel is therefore the proper length for ultimate use, it is not necessary to premeasure, to mark, or to do all of the steps that prior art workers have found necessary in order to make a reinforced drapery heading. For purposes of simplicity, this invention has been described as applied to vertical tablers. However, the tape applicator can be applied equally well to horizontal tablers. The essence of the invention is the transverse movement of the carriage across the frame of the tabler and the automatic feeding of one face of said tape from a spool journaled upon said carriage onto a panel on said tabler, the face of said tape lying in a plane parallel to the plane of the portion of the panel to which the tape is being applied. Further, the word "adhesively" has been used throughout to apply to pressure-sensitive adhesives, thermally-activated adhesives and to chemically-catalyzed adhesives and other bonding agents all well known to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the accompanying drawings wherein:
FIG. 1 is a somewhat schematic front elevational view of a tabler provided with the tape applicator means of the present invention.
FIG. 2 is a right end, elevational view of the device shown in FIG. 1.
FIG. 3 is an enlarged, fragmentary, perspective view of a form of drive means for moving the trolley means of the device. with respect to its frame.
FIG. 4 is an enlarged, partially broken fragmentary sectional view, taken along lines 4--4 of FIG. 2
FIG. 5 is an enlarged, partially broken, fragmentary sectional view taken along lines 5--5 of FIG. 1.
FIG. 6 is an enlarged, partially broken, fragmentary front elevational perspective view of carriage means provided in accordance with the present invention at the lower end of the frame for horizontal movement relative thereto and for tape applicator means and cutting means carried thereby.
FIG. 7 is a schematic diagram of a form of drive means that can be employed to move the carriage means.
FIG. 8 is a schematic diagram of a form of electric circuit that can be utilized to control the carriage drive means.
FIG. 9 is an enlarged fragmentary plan view, with parts in section, illustrating in detail the tape applicator of this invention is use in applying a tape of buckram to the drapery panel
FIG. 10 is a fragmentary, enlarged, partially diagrammatic plan view illustrating in detail another modification for applying adhesive to one side of the tape as it is being applied to the drapery panel.
DETAILED DESCRIPTION
Referring now to the drawings and more particularly to FIGS. 1 and 2, thereof, there is illustrated a vertical tabler 10, that is provided in accordance with the present invention for manufacturing draperies and the like. While it should be understood that the vertical tabler 10 could be used for other purposes, such as curtain manufacturing, etc., the description will be confined to drapes for the sake of clarity and brevity. The vertical tabler 10 is an improved form of one such as that described in detail in the Tuskos U.S. Pat. No. 3,439,438, and in U.S. Pat. No. 3,738,007. As is common to all vertical tablers on the market, the vertical tabler 10 includes an upstanding frame 11 having first and second spaced vertical plane-defining, parallel guide track mounting means 12 and 13 and a trolley 14 which transversely spans the space between the vertical members 12 and 13 and is movably connected thereto for vertical movement with respect to frame 11 by electrical motor 15. The trolley 14 is rectangular in shape and is comprised of at least one transverse member 16 which is provided with gripper means, such as a series of spring clamps 17 to grasp a panel 18 to be formed into a drapery and to vertically position the upper end of the panel 18 with respect to reference means 19 in the form of a board 157 having a rubber backing 158 spanning the lower end of the frame. A drop box 21 is also provided which spans the lower end of the frame 11 to receive the lower end of the panel 18 and to prevent it from coming into contact with the shop floor.
Vertical tracks are provided for the trolley 14 by respectively fixing a pair of channel members 23 and 24 to the vertical frame members 12 and 13 as by welding or other suitable fastening means to extend downwardly from the tops thereof. The generally rectangular shaped trolley 14 is vertically arranged on the front of the frame 11 and preferably includes a second transverse member 25 which is spaced apart from and parallel to its other transverse members 16 and thus forms its lower edge. The two transverse members, 16 and 25 of the trolley are interconnected by a pair of side members 27 and 28 and that respectively form its right and left edges. Each of these side members 27 and 28 of the trolley 10 is provided with rollers 29 that are engaged in the vertical tracks respectively, provided by the members 27 and 28.
In accordance with the present invention, the frame 11 is provided with an additional pair of vertical members, only one of which 30 is visible in the drawings, that are respectively spaced behind and in alignment with the two trolley track bearing vertical frame members 12 and 13. Each of these two rear vertical frame members, such as frame member 30, has its lower end supported by the frame base member 22 and has its upper end connected to the vertical member 12 or 13 or immediately in front of it by horizontal frame member 31 that extends fore and aft of the device 10. The fore and aft top members 31 are interconnected by another horizontal top member 32 which extends transversely between them. Yet, another vertical frame member 33 is provided that is centrally located between the two rear vertical frame members, such as the member 30 and has its lower end supported by the frame base member 22 and its upper end connected to the transverse top frame member 32.
As shown in FIGS. 1-3 and 5, drive means 15 of the of the trolley 14 comprises a reversible rotary electric motor 33 that has its housing 34 fixed to a bracket member 35 which extends horizontally and rearwardly from the right rear, vertical frame member 30 at a higher elevation of the reference means 19. Motor 33 has its rotary operated shaft 36 provided with sheave 37 which is interconnected by a belt 38 to another sheave 39 that is mounted on the right end of the trolley drive shaft 40. The trolley drive shaft 40 extends horizontally between the right and left vertical frame members 12 and 13 and is rotatably journaled in and connected thereto by bearing blocks 41 that are mounted on another pair of horizontal frame members, only one of which 42 is visible in the drawings and extend between the two pairs of front and rear vertical frame members. The trolley drive shaft 40 is provided with sprockets 43L and 43R adjacent its opposite left and right ends, and these sprockets 43L and 43R respectively connected by left and right trolley drive chains 44L and 44R to other sprockets 45L and 45R that are provided on the opposite left and right ends of the driven shaft 46. The driven trolley shaft 46 extends across the top of the frame 11 and is rotatably journaled in additional bearing blocks 47 that are fastened to the top frame member 32. One end of each of the two trolley drive chains 44L and 44R is respectively connected to the left or right bottom corner of the trolley 14, while the opposite end of each chain 44L and 44R is respectively connected to the left or right top corner of the trolley 14.
With this arrangement, rotation of the motor output shaft 36 in the first direction (clockwise as shown in FIGS. 2 and 5) will cause upward movement of the trolley 14 relative to the frame 11, whereas rotation of the motor output shaft 36 in the opposite direction (counterclockwise as shown in FIGS. 2 and 5) will cause downward movement of the trolley 14. Upward movement of the trolley 14 is assisted by a counterweight 48 (shown in shadow in FIG. 1) which is connected to cable 49 which is draped over pulley 50 and is centrally connected on the driven shaft 46.
In accordance with the present invention, the vertical tabler 10 is provided with control means for de-energizing the trolley drive 15 following movement of the trolley 14 to a predetermined distance by the reference means 16. As mentioned in FIGS. 1-5, these trolley drive control means including electric toggle switch 51 for energizing the trolley drive motor 33 to rotate its output shaft 36 in either of the two opposite directions and a pair of electric limit switches 52 and 53 for controlling de-energization of that same motor 33.
The toggle switch 51 is presently physicially mounted within a housing that is fixed to the right front, vertical frame member 13 at the hand level of a typical operator, while the housing of one of the two microswitches 52 is fixed at a similar elevation on the front face of the right, rear vertical frame member 30. The first microswitch 52 has its actuator 52A arranged to extend forwardly for temporary engagement with the cam surface 54 that is fixed on the rear of the right member 28 of the trolley 14 so as to limit downward movement of the trolley 14.
The other of these two microswitches 53 serves to limit upward movement of the trolley 14 by the trolley drive means 15 and is itself mounted for vertical movement relative to the frame 11 by manually operated upper limit switch drive means 55.
The upper limit switch drive means 55 includes a horizontal drive shaft 56 that extends transversely to and is journaled for rotation in the right rear vertical frame 30 at an elevation similar to that of the toggle switch 54. This upper limit switch drive shaft 56 has a hand wheel 57 connected to its right end and carries a sprocket 58. This sprocket 58 is connected by an endless chain 59 to another sprocket 60, carried by driven shaft 61 and is rotatably journaled in the rear end of the right end of the extending top frame members 11.
As is best shown in FIG. 3, the upper limit switch 53 has its housing fixed to a front facing surface of the endless chain 59 with its actuator 53A arranged to extend forwardly for temporary engagment with the cam surface 54 that is fixed on the right rear side of member 28 and the trolley 14 so as to limit upward movement of the trolley 14. The elevation of the upper limit switch 53 can be readily varied through manual operation of the drive means 55 by hand rotation of its hand wheel 57. Manual rotation of the hand wheel 57 in the first direction (clockwise as shown in FIGS. 2 and 3) will cause upward movement of the limit switch 53 with respect to the frame 11 and trolley 14, whereas the rotation of the hand wheel in the second direction, opposite to the first direction (counterclockwise, as shown in FIGS. 2 and 3) will cause the upper limit switch 53 to be moved downwardly with respect to the frame 11 and trolley 14.
As shown in detail in FIG. 4, inadvertent movement of the upper limit switch drive means 55 is prevented by the provision of a spring 62 which axially surrounds its drive shaft 56 and biases the drive sprocket 58 into engagement with a stop 63 fixed on the vertical frame member 30. The sprocket 58 can of course be readily disengaged from the stop 63 by pushing the hand wheel against the force of the spring 62.
In order to facilitate accurate length measurement of the drapery panel 18 and the location of a heading at its lower end, the present invention provides the tabler 10 with measuring means comprising a pair of retractable measuring tapes 64A and 64B. Each of these measuring tapes 64A and 64B is housed in a casing, with the two casings 65A and 65B being fixed side by side on the front surface of the right front vertical frame member 13 at an identical elevation above the reference means 19. Both of these tapes 64A and 64B extend upwardly from their respective housings, with the distal end of one 64A being connected to the housing of the upper limit switch 53 by a first bracket 66A, while the distal end of the other tape 64B is connected to the upper right corner of the trolley 14 by another bracket 66B. The casings 65A and 65B for the two tapes 64A, and 64B are respectively provided with windows 67A and 67B, each having a horizontal indicator line provided thereon.
In operation, the hand wheel 57 is pushed against the spring 62 and rotated to cause the upper limit switch 53 and the distal end of the measuring tape 64A that is connected to it to be moved to a predetermined desired elevation above the reference means which will be indicated by the particular meter mark on that tape 64A which is matched up with the indicator line on the window 67A of its casing 65A. Then, subsequent operation of the toggle switch 51 will energize the trolley drive motor 33 and cause upward movement of the trolley 14 by the trolley drive means 15 until the cam surface 54 carried by the trolley 14 engages the upper limit switch actuator 53A. This upward movement of the trolley 14 will cause simultaneous upward extension of the other measuring tape 64B that is attached to it by the bracket 66B. The two tapes 64A and 64B are so interrelated to one another, the reference means 19, the trolley 14 and the upper limit switch drive chain 59 that, when upward movement of the trolley 14 is stopped by engagement to its can surface 54 with the upper limit switch actuator 53A, the meter mark on the trolley-attached tape 64B that is aligned with the indicator line on the window 67B of its casing 65B will be identical to the meter mark of the other tape 64A which was previously aligned with the indicator line on its casing window 67A through rotation of the hand wheel 57. Thus, any metered tape length that is preset at the indicator line on the window 67A of the casing 65A of the upper-limit switch-attached tape 64A through operation of the hand wheel 57 will be matched by the trolley drive means 15 and automatically stopped there by the trolley drive control means, with the equal actual matched length being indicated by the mark on the tape 64B that is then aligned with the indicator line on the window 67B of its casing 65B.
In order to avoid overriding of either of the two limit switches 52 or 53 by the trolley drive means 15, the present invention further provides disc-type brake means 68 which are best shown in FIG. 5. As illustrated, these brake means 68 include a disc 69 which surrounds and is fixed on the trolley drive shaft 40 between its belt driven sheave 39 and right drive sprocket 43R. This disc 69 is normally engaged (and rotation of the trolley drive shaft 40 prevented) by brake shoe means (not shown in detail) held in contact therewith by one end of a lever 70 which is yieldably urged into its braking position by resilient means such as a tension spring 71 that connects the opposite end of the brake lever 70 to the right front vertical frame member 13. The force of the tension spring 71 can, however, be overcome and the lever 70 operated to release the brake shoe means from the drive shaft brake disc 69 through operation of a linkage 72 by solenoid 73 that is electrically connected in the control circuit (not shown) for the trolley drive 15.
Therefore, as soon as either of the two limit switches 52 or 53 has its actuator 52A or 53A engaged by the trolley cam surface 54, both the trolley drive motors 33 and the brake releasing solenoid 73 will be simultaneously de-energized and there will be simultaneous re-engagement of the brake shoe means with the brake disc 69 with the de-energization in the trolley drive means motor 33.
In accordance with the improvement presented in the present invention, as is best shown in FIGS. 1, 2 and 6-9, the reference means 19 is in the form of a board 157 adjacent the lower end of the frame 11 of the vertical tabler 10 with respect to which the upper end of the inverted drapery panel 18 is vertically positioned by attaching the panel's lower end to the top of the trolley 14 by gripper means such as the spring clamp 17. The tape applicator means 134 and cutting means 82 are combined with the vertical tabler for respective movement relative to the horizontal reference plane defined by the rubber-backed board 157 so as to simultaneously apply a strip of buckram or Pellon from a roll 137 on the panel 18 and to simultaneously trim the lower edge of the panel along a cut 84 that is aligned with the bottom of the board 157. This improved arrangement is particularly advantageous over that described in the afore-mentioned Tuskos U.S. Pat. Nos. 3,439,438 and 3,738,007, in that it eliminates the need for the marking means, the ironing board and the creasing means and permits the panel 18 to be immediately folded upon itself so as to sandwich the buckram tape between the two layers of drapery panel to be secured into a reinforced heading by adhesives, by stitching or by stapling. If a thermally-active or pressure-sensitive adhesive is utilized on the other face of the tape, the ironing board can be utilized to support the heading of the drapery panel for ironing the heading and to adhesively secure the face 138 of the tape to the trimmed end of the drapery panel 18 as disclosed in our co-pending application Ser. No. 505,619.
As illustrated in FIGS. 1 and 2 and 6-9, the applicator means 134 and the cutting means 82 are both mounted on a single carriage 85 which is driven by an electrically-powered drive means 86 for horizontal movement relative to the reference means 19 at the lower end of its frame 11 across the space defined by the vertical trolley guide tracks 23 and 24 for simultaneously trimming the panel's lower edge with an electric cutting means 82 along the cut 84 while the buckram tape is being applied to the drapery panel 18 by the tape applicator means 134. Furthermore, the vertical tabler 10 is also preferably provided with control means, including another toggle switch 87, another pair of normally closed microswitches 88 and 89 for automatically de-energizing the carriage drive means 86 upon completion of each traverse of the space between the vertical trolley guide rods 23 and 24 by means of the carriage 85.
Preferably, the horizontal reference plane defined by the rubber-back board 157, acts as a pressure backing for the idler roller which presses the face 138 of the tape onto the panel 18. Further, in a preferred embodiment, the bottom of the board 157 acts as a guide for the cutting means 82 so that the panel is automatically trimmed at the proper point.
As is shown in detail in FIG. 6, the carriage 85 comprises a plate having one of its ends, 85V hooked upwardly and provided with rollers 91, horizontally journaled thereon. The rollers 91, are, in turn, mounted for rolling movement relative to a carriage track means 92 that are formed on the lower interior of the hollow frame member 93 which is connected to and extends transversely between a pair of downwardly arched frame members 94 that are respectively connected to the bottoms of the left and right vertical frame members 12 and 13 and extend forwardly and upwardly therefrom to an elevation spaced above the horizontal reference plane 19. As shown in FIGS. 6-9, the carriage drive means 86 includes a reversible rotary electric motor 95 that has its housing 96 fixed to a bracket member 97 which is in turn connected to the left end of the carriage track forming frame member 93. The carriage drive motor 95 has its rotary output shaft 98 provided with a sheave 99 which is interconnected by a belt 100 to another sheave 101 that is mounted on one end of a carriage drive shaft 102, that is, in turn, horizontally journaled for rotation at the left end of the carriage track forming frame member 93. The carriage drive shaft 102 extends in a fore and aft direction with respect to the tabler 10, and also mounts a drive pulley 103. The carriage drive pulley 103, is, in turn, connected by a cable 104 to another pulley, 105 which is mounted on a driven shaft 106, that is journaled similarly to the carriage drive shaft 102 and located at the opposite or right end of the frame member 93. The carriage drive cable 104 has one of its ends draped around the carriage drive pulley 103 and connected to the left end of the upwardly hooked end 85V of the carriage plate 85 and has its opposite end draped around the driven pulley 105 of the carriage drive means 86 and connected to the right end of the upwardly hooked and 85V of the carriage plate
With this arrangement, rotation of the carriage drive motor output shaft 98 in a first direction (counterclockwise as shown in FIGS. 1 and 6-9) will cause the carriage 85, to be moved in a first direction, from right to left (as shown in FIGS. 1 and 6-9) whereas rotation of the carriage drive motor output shaft 98 in a second direction opposite to the first (clockwise as shown in FIGS. 1 and 7-9) will cause the carriage 85 to be moved in an opposite direction with reference to the frame 11 and with reference means 19 (from left to right as shown in FIGS. 1 and 6-9).
As further shown in FIGS. 1 and 2 and 6-9, the carriage plate has a tape applicator means 134 mounted thereon in the form of a spindle 135 onto which is journaled a spool 136 containing a buckram roll 137. As is shown, the face 138 of the buckram tape is applied to the drapery panel 18 by pressure idler or applicator roll 156 against the rubber backing 158 of pressure board 157. As the face 138 of the buckram approaches the panel 18, adhesive 139 from the adhesive applicator 160, is applied thereto. As is best shown in FIGS. 6 and 9, in one embodiment this is in the form of a spray nozzle, 165 mounted on upright post 166. An air hose, 169, supplies compressed air from a source (not shown), said air hose being connected to the spray nozzle by means of a normally closed valve 110 operated by an electric solenoid 111.
As is further shown in detail in FIGS. 1 and 2 and 6-9, the cutting means 82 comprises an electrically powered scissors which includes an electric motor, having a winding 112 that is contained within a housing 113 mounted on the bottom of the rearwardly-extending 85h of carriage 85. The scissors further include blades 114 that are aligned with the lower horizontal reference plane comprising the bottom of the pressure board 157.
As shown in FIGS. 1, 2 and 6-9, the carriage drive toggle switch 87 is preferably mounted on the front side of the front, right vertical frame member 13, just below the trolley drive means toggle switch 51 and the two carriage drive microswitches 88 and 89 are respectively mounted adjacent the left and right ends of the carriage drive forming member 93 to form left and right limit switches. As is illustrated in detail in the circuit diagram of FIG. 8, the reversible carriage drive motor 95 includes a pair of windings 95L and 95R, one of which, 95L, is operable when energized to drive its rotary output shaft 98 in a first direction, causing leftward movement of the carriage 85 with respect to the frame 11 and reference means 19 and the other of which, 95, is operable when energized to cause its rotary operated shaft 98 to rotate in the opposite direction and cause the carriage to be moved rightwardly with respect to frame 11 and reference means 19. As shown, the power source for the carriage drive control means comprises another pair of electric power lines L3 and L4. The motor right winding 95R is connected in electrical series with the right limit switch 89 by conductor 115 while the left winding 95L is connected in electrical series with the left limit switch 88 by another conductor 116. The series connected right winding 95R and right limit switch 89 are connected in electrical parallel with the series connected left winding 95L and left limit switch 88 by another conductor 117 to the power line L3. These two electrical paralleled circuits are respectfully connected by conductor 118 and 119 to the fixed poles 87L and 87R of the carriage toggle switch 87 which also has its movable actuator 87A connected in electrical series with a cutting means motor coil 112 on the operating solenoid 11 for the compressed air inlet valve 110 of the spray nozzle, 165 and the other power line L4 by conductors 120, 121 and 122.
Thus, assuming that trolley 14 is in its desired upwardmost position, as shown in FIG. 1, and the carriage 85 is in its left position, with the left end of its upturned front end 85V engaged in and opening the actuator 88A of the left limit switch 88, the carriage drive means 86 can only be energized and the solenoid tape applicator means 134 and the cutter drive means energized simultaneously therewith, by moving the carriage toggle switch actuator 87A from its first left position shown in shadow lines in FIG. 9 where it engages one of the fixed poles 87L of the toggle switch 87 to its first right position shown in full lines in FIG. 9 where it is engaged with the other fixed pole 87R and consequently disengaged from the first fixed pole 87L of the carriage toggle switch 87. This movement of the toggle switch will continue to cause energization of the carriage drive means motor winding 95R and the spray nozzle 165 and the cutter means 82 and rightward movement of the carriage 85 until the carriage 85 completes its traverse of the space between the vertical guide tracks 23 and 24. Then, the actuator 89A of the right limit switch 89 will be engaged and opened by the right end of the roller provided end 85V of the carriage 85, to thus simultaneously de-energize the carriage drive motor 95, the cutting means winding 112 and the solenoid 111 for the compressed air supply 110 for the spray nozzle 165. At this point, the buckram tape is cut and the carriage returned to the first position for the next panel.
Referring now to FIG. 10, another modification of the adhesive applicator 160 is shown. In this case, the roll of buckram 137 on spool 136 is again suspended on the spindle 135 of carriage 85. The face of the tape, 138, is rolled between an adhesive applicator roll 172 which is held in position against the pressure roller 174 again journaled on bracket 175 and biased into position by spring 176. The roll for the adhesive roller is fed from a standard adhesive reservoir 170 by means of feed tube 171 and the buckram tape with the glue supplied is fed between the idler roller 156 and the rubber backing 158 of pressure board 157 to be applied to the drapery panel 18.
Further, it is within the scope of this invention to utilize pressure-sensitive tape disclosed in our co-pending application Ser. No. 648,146. In this case, all that is necessary is mount the buckram roll onto the spindle 135, to pull loose the release member from the pressure-sensitive area and apply the release member to a hook or other device on the frame and thereafter energize the carriage for transverse movement by means of a toggle switch, previously indicated. In this manner, the release member is stripped from the tape as the carriage moves transversely across the frame. At the end of the traverse, the tape is again cut and the carriage is moved back to its first position for application of tape to the next panel to be mounted on the device.
Further, it is within the scope of this invention, to support the panel or a portion thereof in a horizontal plane and to position the carriage with the spool of tape journaled thereof for transverse movement across the panel in a perfectly straight line so as to feed one face of the tape in a plane parallel to the plane of the portion of the panel to which the tape is being applied onto said panel so as to bond the tape thereto. The essence of the invention, then, is the transverse movement in a perfectly straight line of the carriage and of the spool of tape mounted on said carriage across the panel suspended on a tabler, and the automatic feeding of one face of said tape onto said panel in a plane parallel to the plane of the portion of the panel to which the tape is being applied.
As previously mentioned, it is within the province of this invention to utilize a tape containing pressure-sensitive tape on both sides, so that the trimmed end of the drapery panel 18 can be folded up onto the other face of the pressure-sensitive tape for sandwiching the tape between the two layers of drapery. With the tape temporarily or permanently bonded to both layers of the panel, it is not necessary to stich the tape into the panel. Since some panels are as much as 20 feet in width, the elimination of this horizontal stitching operation is a major labor-saving advantage. The panel, therefore, can be taken directly to the pleating operation where the vertical stitches, forming the pleats, are placed into the reinforced heading. These pleats are sufficient to permanently secure the tape into the reinforced heading.
Many modifications will occur to those skilled in the art from the detailed description hereinabove given and such is meant to be illustrative in nature and non-limiting so as to be commensurate in scope with the appended claims.
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This invention describes a process for applying a reinforcing or stiffening tape such as buckram or Pellon (registered trademark of the Pellon Corporation, New York, N.Y.) to a panel of drapery or other material directly, without the necessity of pre-marking, measuring or stitching. This is accomplished by the step of adhesively bonding the strip of reinforcing tape near the bottom edge of a panel suspended from the opposite end. Thereafter, the panel and the reinforcing strip adhesively secured thereto, is folded over itself and the reinforcing tape sandwiched between the two layers of panel and secured thereto in the form of a reinforcing heading. The reinforcing tape is mounted in the form of a spool onto a carriage mounted near the bottom of the frame of the tabler. The carriage is mounted for transverse movement across the frame in a straight line so as to adhesively supply one face of the reinforcing tape onto the edge of the panel suspended from the tabler. Since the carriage moves in a perfectly straight line, and since the panel is suspended on the tabler, the strip of adhesively applied tape marks the proper point at which the panel should be folded over onto itself to form the reinforced heading for a panel of the proper length.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to an arrangement for recording data on a magnetic recording medium by use of an amplifier at whose inputs data signals allocated to the data to be recorded, and magnetic bias signals, are present. Outputs of the amplifier are connected to a magnetic head to record the data on the recording medium.
2. Description of the Prior Art
An arrangement comprising an amplifier is usually employed for recording data on a magnetic recording medium, for example a magnetic tape or a magnetic disc. Data signals are allocated to the data to be recorded and magnetic bias signals are supplied to the input of this amplifier. Its outputs are connected to a write head in a magnetic head which records the data on the recording medium. Such an arrangement is disclosed, for example, by German published application No. 32 33 489. In this known arrangement, the data signals and the magnetic bias signals are supplied to an amplifier stage of the amplifier. The outputs of the amplifier stages are connected in parallel and are connected to the terminals of the two series-connected windings of the magnetic head at whose center tap an operating voltage is present. The amplifier stages are fashioned as switching elements so that the current flowing through a respective winding of the magnetic head exhibits extremely steep signal edges.
A further arrangement for recording data on a magnetic recording medium is disclosed by U.S. Pat. No. 4,383,281, incorporated herein by reference. In this known arrangement, two amplifier stages connected in parallel at their output sides are also provided, these being supplied with the magnetic bias signals or the data signals. Every amplifier stage is designed as a differential amplifier, whose common branch is designed as a current source, and whose inputs are supplied with the respective signals either not inverted or inverted. In this known arrangement, the current flowing through the magnetic head exhibits very steep edges since the two differential amplifiers are driven by the magnetic bias signals or the data signals whose signal edges are steep.
Since the edges of the write current flowing through the magnetic head are extremely steep, the time-wise change of the write current in the magnetic head is extremely large and the voltage at the magnetic head would move towards infinity if the magnetic head were loss-free and did not exhibit any stray capacitances. This can result in the fact that, due to a voltage limitation, flux changes allocated to the data signals and to the magnetic bias signals are modified, this potentially deteriorating the reliability against malfunction and the reliability against errors in the recording of the data.
SUMMARY OF THE INVENTION
It is an object of the invention to specify an arrangement for recording data on a magnetic recording medium by means of which reliability against malfunction and reliability against errors can be increased.
According to the invention, inputs of the amplifier allocated to the magnetic bias signals and/or to the data signals are preceded by filters designed as low-pass filters which delay the magnetic bias signals or the data signals respectively, and thus limit their steepness to a desired value.
The arrangement of the invention has the advantage that the data can be recorded with great precision on the magnetic recording medium, and thus can be played back with high reliability by means of a read head. The employment of the filter preceding the amplifier requires little expense since the filters can be constructed with passive components.
It is possible to supply only the magnetic bias signals or the data signals to the amplifier via a respective filter; however, it proves expedient to supply both the magnetic bias signals as well as the data signals to the amplifier via respective filters.
In case the amplifier has a respectively separate amplifier stage both for the magnetic bias signals as well as for the data signals to which the magnetic bias signals or the data signals are supplied in non-inverted and inverted fashion, it is expedient to precede the inputs of every amplifier stage by a filter at which the respective signals are present in non-inverted and inverted fashion and whose outputs are connected to the inputs of the respective amplifier stage. The filter is preferably fashioned as a RC low-pass filter. Given a design of the filter for the feed of inverting and non-inverting signals, it is advantageous when every filter contains two series connected resistors at which the non-inverted or inverted signals are present, and which contains a following, parallel capacitor whose terminals are connected to the inputs of the respective amplifier stage.
In case the amplifier stages are designed as differential amplifiers, the corresponding signals are present at the inputs of every differential amplifier in non-inverted and inverted fashion via a respective filter.
Given employment of differential amplifiers as amplifier stages, it is beneficial when the write current supplied to the magnetic head is adjustable in the common branch of every differential amplifier, and is adjustable on the basis of digital data words which are converted into control signals for the respective differential amplifier by means of a respective digital-to-analog converter.
In case a plurality of write heads are provided in the magnetic head, it is advantageous when a switch unit is arranged between the amplifier and the magnetic head, this switch unit connecting the amplifier to one of the write heads upon employment of a channel selection stage.
A further improvement of the recording can be achieved in that the corresponding write current is briefly boosted before and/or after every signal edge of the data signals. For this purpose, a pulse generator is provided which emits a corresponding control signal to the amplifier at every signal edge of the data signals.
In order to also avoid steep signal edges of the write current here, it is advantageous when the pulse generator contains an integrating element.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block circuit diagram of the arrangement of the invention;
FIG. 2 is a time diagram of signals at various points of the arrangement shown in FIG. 1; and
FIG. 3 is a circuit diagram of the arrangement of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The arrangement shown in FIG. 1 contains an amplifier A whose outputs are connected to a respective write head in a magnetic head H via switch units SW1 and SW2. It is assumed in the illustration of FIG. 1 that the write head formed of two windings W1 and W2 is selected, and switches within the switch unit SW1 are closed by a channel selection circuit CH1. The switches in the switch unit SW2 are opened by a channel selection circuit CH2.
The amplifier A contains switch-over units CS1 and CS2 which supply a write current IW respectively generated in current sources CG1 or CG2 either to a terminal of the winding W1 or to a terminal of the winding W2. An operating voltage U is present at the respective other terminal at a common tap.
A clock generator BG generates high-frequency magnetic bias signals B which are supplied to the switch-over unit CS1 via a filter F1 as filtered magnetic bias signals FB. Dependent on the momentary value of the magnetic bias signals FB, a write current IB allocated to the magnetic bias signals B is supplied to the various terminals of the write head. The size of the write current IB is determined in the current source CG1 by a control signal S1 which is output by a control unit BA. The control unit BA, for example, can contain a digital-to-analog converter which generates the control signal S1 from a corresponding digital data word.
A data source DS generates data signals D which are allocated to the digital data to be recorded. These data signals D proceed via a filter F2 to the switch-over unit CS2 as filtered data signals FD, and the unit CS2 conducts a write current ID allocated to the data signals D to the various terminals of the write head likewise dependent on the momentary value of the data signals FD. The write current ID is set in the current source CG2 by control signals S2 which are generated in a control unit DA in a way similar to the control signals S1. In addition, a pulse generator PG can be provided, this being driven by the data signals and outputting control signals S3 to the current source CG2. These control signals S3 briefly boost the write current ID at every signal edge of the data signals D.
Since the outputs of the switch-over units CS1 and CS2 are connected in parallel, a summation of the write current IB and ID occurs in the write head and a write current IW results. This write current flows from the voltage source for the operating voltage U via one of the windings W1 or W2, via the switch unit SW1, via the switch-over unit CS1, and via the switch-over unit CS2 to the current sources CG1 and CG2.
Further details of the arrangement shown in FIG. 1 shall be set forth below in conjunction with the time diagrams shown in FIG. 2.
The magnetic bias signals B output by the clock generator BG are shown as non-inverted and inverted magnetic bias signals B1 or B2 in FIG. 2. The filter F1, which is designed as a low-pass filter, obliterates and delays the edges of the magnetic bias signals B1 and B2, and limits their steepness. Thus, the filtered magnetic bias signals FB1 or FB2 are generated. The data signals D are likewise output by the data source DS as non-inverted and inverted data signals D1 or D2, and are obliterated in the filter F2 in a way similar to the magnetic bias signals B1 and B2. Thus, the filtered data signals FD1 and FD2 are output to the switch-over unit CS2.
The switch-over units CS1 and CS2 are designed as analog switches, so that the write currents IB and ID do not exhibit a rectangular curve, but likewise exhibit signal edges having a limited slope. In the pulse generator PG, a pulse P is generated at every signal edge of the data signals D, this pulse P being likewise supplied to the current source CG2 after filtering in order to briefly boost the write current ID after every signal edge of the data signals D. The write current ID shown in FIG. 2 thus results when, at point in time t1, the data signal D has an edge which should optimally coincide with an edge of a magnetic bias signal B. At point in time t3, the pulse P is ended and the write current ID in one of the windings W1 or W2, for example in the winding W2, comprises the curve shown in FIG. 2. If no write current ID were present, the write current IB in the winding W2 would likewise have the curve shown in FIG. 2. However, the write current ID and the write current IB are summed, so that the overall write current IW shown in the winding W2 results when the data signal D1 exhibits the illustrated binary value. During the illustrated chronological duration, no write current ID flows through the windings W2 since the switch-over unit CS2 is in the position shown with solid lines. However, a corresponding write current IB does, such that the sum of the write currents IB flowing through the two windings W1 and W2 is constant. The analogous case applies when the data signal D1 changes its binary value since the write current ID no longer flows through the winding W1, but through the winding W2.
In the circuit diagram of the arrangement shown in FIG. 3, the switch-over units CS1 and CS2 are component parts of a differential amplifier comprising the transistors T1 and T2 or T3 and T4. The current sources CG1 and CG2 of the differential amplifier each contain a transistor T5 or T6, and a resistor R1 or R2 arranged in series therewith. The control signals S1 or S2 for setting the write current IB or ID are each supplied via resistor R4 or R3.
The magnetic bias signals B1 and B2 are supplied to the bases of the transistors T1 or T2 via the filter F1 as filtered magnetic bias signals FB1 or FB2. The filter F1 contains two serial resistors R5 and R6 and a capacitor C1. In a corresponding way, the data signals D1 and D2 are supplied to the bases of the transistors T4 or T3 via the filter F2 as filtered data signals FD1 or FD2. The filter F2 is fashioned in a way similar to the filter F1 and contains resistors R7 and R8 as well as a capacitor C2.
The switch units SW1 and SW2 are each formed of two transistors T7 and T8 or T9 and T10 whose bases are selected by control signals S4 or S5 output by a channel selection unit CH1 or CH2. The switch units are selected in order to supply the write currents IB and ID either to the write head formed of the windings W1 and W2 or to a write head in the magnetic head H formed of the windings W3 and W4.
The data signals D2 are also supplied to the pulse generator PG which generates the pulses P by use of a delay element formed of a resistor R9 and a capacitor C3, and by use of an EXCLUSIVE-OR element G, whereby the pulse duration of the pulse P is defined by the time constant of the RC element. The pulse P proceeds via an integrating element formed of a transistor T11 and of capacitors C4 and C5 to the current source CG2 as signal S3. There, it is supplied to a resistor R10 which is arranged parallel to the resistor R2. During the presence of the signal S3, the transistor T11 is activated and the resistor R10 is switched parallel to the resistor R2, so that the write current ID is briefly boosted.
When, at point in time t1, the magnetic bias signals B1 and B2 and the data signals D1 and D2 assume binary values shown in FIG. 2, the transistors T1 and T3 are inhibited and the transistors T2 and T4 are activated. Given the assumption that the signal S4 activates the transistors T7 and T8 as a consequence of a channel selection, and the signal S5 inhibits the transistors T9 and T10, a write current IW now flows from the voltage source for the operating voltage U via the winding W2 and the transistor T8. Write current IW flows as write current IB via the transistors T2 and T5 and via the resistor R1. Write current IW flows as write current ID via the transistors T4 and T6 and the resistor R2 as well as via the resistor R10 and the transistor T11.
When, at point in time t2, the magnetic bias signals B1 and B2 change in binary value, the transistor T1 is activated and the transistor T2 is inhibited. The write current ID thus continues to flow via the winding W2 and the transistors T8 and T4. However, the write current IB flows via the winding W1 and the transistors T7, T1, and T5. The write current IB in the transistor T5 does not change since the transistors T1 and T2 alternately carry the write current IB, and as a consequence of the filter F1, the write current IB is delayed and the edge steepness when switching the transistors T1 and T2 is reduced. Thus, no excessive voltages occur at the windings W1 and W2.
The pulse P is ended at point in time t3 and the transistor T11 is inhibited, so that the write current ID is slowly reduced to a nominal value.
At point in time t4, the binary values of the magnetic bias signals B1 and B2 change again, so that, as in the case at point in time t1, the transistor T1 is inhibited and the transistor T2 is activated.
When, at a later point in time, the data signal D1 changes in binary value, the transistor T4 is inhibited and the transistor T3 is activated and a new pulse P is simultaneously generated. The write current ID then flows via the winding W1, the transistor T7, and the transistor T3 to the transistor T6. Here too, the filter F2 carries out a soft switching so that no excessive voltages occur at the windings W1 and W2 and the write current ID remains constant. When a recording is to occur with the write head formed of the windings W3 and W4, the transistors T9 and T10 are activated by the signal S5, whereas the transistors T7 and T8 are inhibited by the control signal S4. The events in the windings W1 and W2 then repeat correspondingly in the windings W3 and W4.
LC low-pass filters can also be employed as filters F1 and F2. However, the RC low-pass filters prove very cost-beneficial. It is also possible to employ only a single filter either for the magnetic bias signals B or for the data signals D.
Although various minor changes and modifications might be proposed by those skilled in the art, it will be understood that I wish to include within the claims of the patent warranted hereon all such changes and modifications as reasonably come within my contribution to the art.
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In an arrangement for recording data or a magnetic recording medium, the inputs of an amplifier whose outputs are connected to a magnetic head are preceded by filters which delay magnetic bias signals and data signals supplied to the amplifier and limit their steepness. Undesirably high voltages at the magnetic head as a consequence of excessively steep edges of a write current supplied to the magnetic head are thus avoided, and the reliability of the recording of the data on the magnetic recording medium is increased.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to interactive gaming via a television system and communications network.
[0003] 2. Description of Related Art
[0004] Interactive gaming provides entertainment for the general public in many forms, such as PC gaming, specific console formatted gaming and gaming via a communications network with a central server. Each form of interactive gaming presents various advantages and disadvantages. Some gaming allows a multitude of players access but may be subject to equipment specifications such as server limitations, connection speeds, internet service provider, broadband capabilities, video cards and/or peripheral equipment. Specific formatted gaming is limited to participants with direct access to the gaming console, i.e., Playstation, X-Box, and Gameboy. Gaming via a communication network may allow many users but is subject to the communication capabilities of each user and are limited to users who have access to the communication network. Frequently, users may lose their connection to the central gaming server due to various network problems. By using existing television systems for interactive gaming one may increase the potential market for interactive gaming and diminish some of the shortcomings associated with interactive gaming via a communication network. Other interactive television gaming systems include Bell ExpressVu in Canada and Visionik in Denmark. These interactive systems however lack flexible and effective user friendly functionality.
[0005] U.S. Pat. No. 6,193,610 to Junkin relates to an interactive apparatus and method that allows participants to compete in an interactive game occurring in real time or as a taped broadcast of a real time event. The interactive gaming of Junkin may be accomplished by accessing an online version of the game while the corresponding event airs live or is rebroadcast to the participant on a television. Junkin describes an interactive gaming scheme that allows the participants to select individuals and/or teams, who are engaged in an event being broadcast, from a contest roster database. The participants form a team from the roster database and scores are developed based upon the individual's and/or team's performance in the televised event. The interactive gaming of Junkin is specifically associated with the televised event and dependant upon its outcome. Junkin does not discuss or disclose methods of interactive gaming in an independent format where users actively control the outcome and strategy related to the game via the television system.
[0006] U.S. Pat. No. 6,227,974 to Eilat et al. relates to a gaming method for use with an interactive game that a player plays with a player unit having an interface device which is coupled to a television and to at least one communication network. Eilat describes a method which enables two players to engage in an interactive game via a television through a communication network. Eilat allows users to transmit their photos that are incorporated in the interactive game and allows the players play the game while viewing the game on their respective televisions. Eilat essentially describes interactive games for two participants who view the game on a television and other viewers may watch the interactive play. U.S. Pat. No. 6,447,396 to Galyean, III et al. (Galyean) relates to an interactive computer game with a television broadcast, where a central control establishes a large virtual environment in which viewers participate with characters either controlled or designed by them. The interactive game of Galyean allows users to directly control or influence characters within an active region with defined boundaries that encompass part of the virtual environment that is much less that the total environment.
SUMMARY OF THE INVENTION
[0007] The present invention relates to interactive gaming via a participant's television. In one exemplary embodiment, the interactive gaming involves a trivia game which consists of one or more levels of play, wherein each level presents participants with increasingly difficult questions. Participants answer multiple questions related to a predetermined subject such as entertainment, sports, science, culture, art and/or health. Upon completion of a game or skill level within a game, participants may submit their respective scores to a central database and registry at an Interactive Game Center (IGC), i.e. server, where the score is compared to scores submitted by other participants. The IGC tallies scores in real time and sends the results back to each participant's set-top box, thereby allowing the users to compete with other players within a predetermined region. Participants may periodically, i.e. upon completing a question or a skill level, quit or pause the game for any desired time period. Participants may execute the quit or pause function at any time during the game.
[0008] Subscribers to the present invention may play the game through a conventional television. Subscribers may compete with other subscribers in real time due to the real time updates provided through the IGC. The subscriber may view results that include the subscriber's ranking or standing among the group of participants within the particular game.
[0009] The present invention may use the DIRECTV Interactive programming via the DIRECTV satellite system. Advantageously, a broadcaster may generate revenue by charging subscribers for playing the game and sponsors for advertising. The present invention provides a new television interactive game that is more exciting and user friendly than prior art. Subscribers have an unlimited number of competitors who may reside any where in the world. Participants may submit their respective scores to the IGC for tallying and ranking, or participants may choose to merely play without submitting their scores.
[0010] The present invention includes a database of questions that reside within a set-top box where the database is refreshed every hour. Participants may compete in a particular game at any time. New games may be started at pre-determined periods of time, such as every one or two weeks. Each new set of questions may give rise to a new contest between the participants. The database of questions may be associated with different skill levels to ensure a challenging gaming experience for all participants.
[0011] Advantageously, participants may pause the game after any question and turn off the television or switch to other programming. Participants may then return to the game at any time. At a predetermined level or after all of the proffered questions have been asked, participants may submit their respective score to be compared with others. The database of questions includes a substantial volume of questions in order to avoid repetition and to maintain the participant's interest.
[0012] During each game, each question must be answered within a predetermined time period. A participant may achieve a higher score by answering questions as quickly as possible. In one exemplary embodiment, if the predetermined time period expires, then the participant cannot answer the question, or in an alternative embodiment, the participant may submit an answer after expiration of the predetermined time period simply to determine if the participant actually knew the correct answer. Other variations of the general question/answer game format include supplying answers immediately or not supplying answers until completion of predetermined segments. If the participants are not supplied with a correct answer, then the question or a related question may be used again for this participant.
[0013] Participants subscribe to the interactive gaming via their respective set-top box. The set-tip boxes permit multiple participants to subscribe through a single set-top box. In an alternative embodiment, some participants may play the interactive games without subscribing, however unsubscribed participants merely answer questions for entertainment purposes and may not directly and interactively compete with any other participants. Furthermore, several set-top boxes may be installed at a particular location enabling a team of participants to compete with other teams within a predetermined region.
[0014] In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1A shows an exemplary schematic diagram of a data flow according to the present invention.
[0016] FIG. 1B shows an exemplary set top box configuration according to the present invention.
[0017] FIG. 2A shows a flowchart related to a scoring algorithm according to the present invention.
[0018] FIG. 2B shows a second flowchart related to the scoring algorithm according to the present invention.
[0019] FIG. 2C shows a third flowchart related to the scoring algorithm according to the present invention.
[0020] FIG. 2D shows a fourth flowchart related to the scoring algorithm according to the present invention.
[0021] FIG. 3 shows an exemplary illustration of a portal screen of according to the present invention.
[0022] FIG. 4 shows an exemplary main game screen according to the present invention.
[0023] FIG. 5 shows an exemplary question screen according to the present invention.
[0024] FIG. 6 shows an exemplary correct answer screen according to the present invention.
[0025] FIG. 7 shows an exemplary incorrect answer screen according to the present invention.
[0026] FIG. 8 shows an exemplary level completion screen according to the present invention.
[0027] FIG. 9 shows an exemplary a score registration screen according to the present invention.
[0028] FIG. 10A shows a flowchart related to a gaming sequence according to the present invention.
[0029] FIG. 10B shows the further steps of the flowchart related to the gaming sequence according to the present invention.
[0030] FIG. 10C shows the further steps of the flowchart related to the gaming sequence according to the present invention.
DETAILED DESCRIPTION
[0031] The present invention enables a dynamic interactive game platform for use with a conventional television system. The present invention allows multiple users to participate in an interactive game via a television system that allows user interaction, continuous real-time scoring, multiple achievement levels and unique scoring schemes. The scoring scheme associated with the present invention awards points for correct answers, correct answers within a pre-determined time period, bonus points for consecutive correct answers, weighted correct answers associated with each achievement level, and tallies the score in dynamic real time. The present invention accomplishes real time interaction through the use of a satellite television system and a central interactive gaming center.
[0032] A data flow for a system according to the present invention is shown in FIG. 1A . A gaming system 25 includes a question database 12 for use with a game application 14 , such as an application for a trivia game. The gaming system 25 transmits data from the question database 12 and the trivia application 14 to a real-time update server 16 . The update server 16 transmits data to an uplink server 18 that relays the data to a satellite 20 . The satellite 20 then transmits the data from the question database 12 and/or game application 14 to a user's television STB 22 . The questions and gaming application for playing the trivia game reside in the user's STB 22 . The user may then interactively review the questions and provide answers via the STB 22 . Questions are then asked and answers evaluated from the STB 22 . A central broadcast center 10 includes, inter alia, the gaming system 25 , the unlink server 18 , the real time server 16 and transaction server 24 .
[0033] In an exemplary embodiment, approximately 100 questions per level may be provided to a user periodically, i.e., hourly. The user, after playing the game may then submit their final score for a level or the entire game to a transaction server 24 . The final scores are transmitted through a telephone from the STB 22 to the transaction server 24 . However, other means for transmitting the final scores are conceivable, such as data including scores from several STBs 22 may be sent to the transaction server 24 for the game. As shown in FIG. 1A , data from the STB 22 is transferred via a modem to a point of presence (POP) 23 and then transmitted over the internet 15 to the transaction server 24 .
[0034] From the transaction server 24 , the data sent by the STBs 22 is placed in a high score database 26 . The high score database 26 stores the scores from several users for comparison and ranking purposes. A list of high scores and other related data can then be transmitted back via the uplink server 18 to the user so that the user may see the user's score as compared with the other competitors. Data transmission may be provided through a real time update server 16 to an uplink server 18 and uplink server 18 then transmits a question packet from the question database 12 and the game application 14 to the STB 22 . Based upon the data stored in the high score database 26 , a prize may be sent to the user with the high score for a particular period such as two weeks, one month or year. The present invention also facilitates the ability to provide questions on different types of knowledge for various gaming contests.
[0035] In one exemplary embodiment, the question database 12 and the high score database 26 are stored in computer systems such as the Sun Ultra 5 having a Sparc 400 MHz processor and 256 MB of RAM, using the Solaris 8 operating environment and MySQL 3.53 database management software. The uplink server 18 may be a Sun Ultra 10 having a Sparc 400 MHz processor and 256 MB of RAM, using the Solaris 8 operating environment. The real-time update server 16 may be an HP NetServer LPr with a Pentium III 800 MHz processor, using Microsoft Windows 2000 Server operating system and the .NET platform. The transaction server 24 may be a Sun Blade 100 having a Sparc II 500 MHz processor. The RAM is preferred to be at least 512 MB and the computer may use the Sun Solaris 8 operating environment and Tomcat 4.1 Web Server software. The STB 22 may be a GLA 2.5 version using OpenTV EN 2.1 software for its applications. In one exemplary embodiment, the STB 22 has 2 MB of RAM and 3 MB of Flash memory. Equivalent software and hardware for the servers, databases and STBs may be substituted for the items described. Also, the question database 12 and the high score database 26 may be located in the same hardware system.
[0036] Referring now to FIG. 1B , a detail exemplary configuration for the STB 22 is shown. Data flows into and from the STB 22 via input 227 and output 229 . A STB database 221 stores question packets sent to the STB 22 from the gaming system 25 . The STB 22 also includes a gaming application 223 which executes the interactive gaming functionality for the user. The user interacts with the STB 22 via a handheld device 22 a that transmits user commands to the STB 22 via a wireless transmission 22 b . A user transmitter/receiver 22 c receives the commands from the handheld device 22 a and relays 223 b these commands to the STB gaming application 223 . The transmissions to and from the STB gaming application 223 include a question protocol to the television 220 and user replies, answers and commands, via the handheld device 11 . The gaming application 223 includes applications which tally store a base score 223 c and a bonus & time score 223 d.
[0037] Referring to FIG. 2A , an exemplary scoring algorithm is depicted. Initially, a score is calculated for a particular question as shown in step 100 . The algorithm then tallies a base score, step 200 , calculates time based component, step 300 , calculates a bonus score component, step 400 and then calculates a score for the given level, step 500 . To output the complete total score, the algorithm sums the score for each completed level and then outputs the sum as the total score for the particular user. FIGS. 2B through 2D show sublevels associated with the total score algorithm of FIG. 2A . Referring to FIG. 2B , the score for a particular question, step 100 , includes: calculation of the total time to complete the question step 110 ; determination of the total time to complete a question on level (i); and using these two time components to determine the output score s j ′(i) for a particular question, step 120 , where s j ′(i)=(t a (i)−t j /t a (i))+ε, for correct answers only where ε=a fudge factor. In calculating the time base score step 300 , the algorithm provides a sum total of each score for all questions, step 310 . The summation of the total scores is then multiplied by the tally base score and a level factor i, step 320 . The result of the multiplication outputs a time base score at step 330 which is used in step 300 of FIG. 2A . The bonus score component step 400 of FIG. 2A is calculated according to the steps of FIG. 2D . Initially, an input of the total number of questions asked Q(i) asked , step 410 , is followed by an input of the total number of questions correctly answered Q(i) correct , step 420 . A ratio is calculated in order to determine the percentage of correct answers. The correct percentage is then multiplied by the base level bonus score times the level factor i at step 440 , then the bonus score component b i is output at step 450 . As one may ascertain from the above algorithm, a user's score includes the number of correct answers, time associated in supplying the correct answers and an implementation of bonus scoring based thereon.
[0038] In one exemplary embodiment, the steps for playing the game are as follows. A portal screen 28 is provided, as shown in FIG. 3 . The screen 28 allows the user to pick any of a number of games to be provided. Once the user selects a game, the user is brought to a main game screen 50 as shown in FIG. 4 . The user enters a unique identifier 52 to play the game, where the identifier 52 is shown along with other information such as the location. On the initial screen, the points and level of play have not yet been recorded for the user. However, scores and rankings 56 , 58 may be displayed for those who have already entered their score. Although a limited number of scores may be displayed on the screen, a scroll bar 60 may be used to display a longer list of scores. The main screen 50 allows the user to play 62 , enter the results 64 or change the user identifier playing the game 66 . The user is also given directions 68 regarding the game.
[0039] After the user elects to play a particular game, the game begins with a question screen 70 as shown in FIG. 5 . As shown, the question screen 70 provides information which the user may use for competing in the game. As shown, data for the user includes level of play 72 , the number of questions asked for the level played 74 , number of correct answers toward the number needed to advance to the next level 76 , question category 78 , time remaining to answer 80 , points awarded for a rapid answer 82 and total points accumulated so far 84 . Extra points may be awarded based upon the percentage of correct answers answered previously for the level being played and upon the level of play. The display of these extra points 86 is also shown on the question screen 70 . Also on the question screen 70 are the question 88 and the answer choices 90 . As shown, the number of right answers required per level is ten.
[0040] If the user correctly answers the question in the allotted time, a correct answer screen is provided 100 , as shown in FIG. 6 . The number of correct answers 76 is incremented as well as the points awarded 82 and the total points received 84 . In addition, the amount of extra points 86 earned is incremented for the higher ratio of correct answers to questions asked. A message 92 informs the user that the answer is correct and offers the user the choice of moving forward or going back to the main menu.
[0041] If an incorrect answer is given, or time runs out, an incorrect answer screen 101 is provided as shown in FIG. 7 . In the incorrect answer screen 101 , the number of points 82 awarded is shown to be zero, and the extra points 86 to be awarded is diminished because the ratio of correct answers to answers given has been lowered. A message 102 is provided which informs the user that the answer is wrong. In addition, the message 102 offers the user the choice of moving forward or going back to the main menu.
[0042] After the number of answers needed to advance to the next level is obtained, a level completion screen 110 is provided as shown in FIG. 8 . A message 112 is provided informing the user, and a choice may be provided to continue to the next level or return to the main menu. If the user returns to the main menu, the user may elect to submit score results to the transaction server 24 . The score registration screen 120 shown at FIG. 9 is provided if the user submits a score. As shown, the user's identifying information 52 and level score 53 is provided on the level completion screen. A high score roster 122 is also provided. In the roster, the high score list for the game currently residing in players' STBs is provided to all users. This high score list is updated throughout the residency of the game in the STBs. If an individual user makes one of the high scores for the game, then the user's name is added to the roster. The user's data is sent to the high score database 26 which is transmitted to the real-time update server and then transmitted to the respective STB for each user.
[0043] The user's score may be visible for a level or the game presented on the television almost instantly upon registration of the score. A portion of this information may be given, or additional information may be given, depending upon what type of game is provided. For example, the game may be based upon math or geography or any other field of knowledge. Appropriate information may be provided to make each type of game interesting.
[0044] FIGS. 10A and 10B show a flow chart which sets forth the steps for interactive gaming according to the present invention. Initially, a user tunes to the game portal via the set top box, step 810 and selects the interactive trivia game from the game portal, step 820 . Upon selection of the trivia game, the user inputs a user id, step 870 . The trivia game allows multiple users to play the game via a single set top box. After the initial selection of a user, the trivia game's main menu appears, step 830 . The user may choose four options while on the main menu exit the game, step 840 , play the game step 850 , submit scores 860 or select another user 870 . If the user chooses to play the trivia game 850 , then the game sequence is initiated as shown in FIG. 10C . The questions as sent from the gaming system 25 are uploaded for the current level, step 880 . The user begins the game by answering the current question 890 and then continues to the next question and/or next level if the user has completed the current level questions. The user may also opt to end the game at any time after the complete of a question. So the user answers the current question 890 and decides whether to continue 894 . The gaming application 223 determines if the level is complete 896 based upon the number of correct answers supplied by the user and notifies the user. Next the gaming application 223 determines if the game has been played through completion, step 898 , if not then the trivia engine 223 a increments the user to the next level 882 or alternatively if the game is complete the game ends. Upon incrementing to the next level trivia game cycles back to step 880 and the user views and answers the current question, step 890 .
[0045] Further aspects of the interactive game include a three level game that may be played at one or more levels, where the point score equals zero, and the maximum score equals 12,000. Users must provide ten correct answers to advance to the next level. The score for each level has two components: (1) one component is based upon how quickly the correct answer is provided; and (2) the other component is based upon how many questions are required to get the required ten correct answers.
[0046] Each question has a base value equal to 100 times the level of the question. When presented with a question, the user will have a predetermined period of time to answer the question, such as 30 seconds times the level of the question. The more time a user uses to input a right answer, the fewer points received. A visual indicator shows the time and available points ticking down. If the points available drops to zero, the user can no longer answer the question and the user must move on to the next question to keep playing.
[0047] The first score component for a level is calculated by summing up the score of each correctly answered question and multiplying it by 100 times the level. The second score component for a level is calculated by multiplying 100 times the level by the ratio of number of questions answered correctly over the number of questions asked in total. Preferably, the points available are provided to the user in real time. Thus, a diminishing progress bar tells the user the points available if the answer is given instantaneously. The progress bar starts at 100% and drops incrementally to 0%. Color change for the time bar as the time lapses is also preferred. The second score component of the score for completing the level is updated after each question is answered. The cumulative score is updated after each question is answered. Other scoring methods are contemplated, such as eliminating the time factor in scoring or giving more value to the time factor.
[0048] The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made there from within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
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A system and method for interactive gaming includes a central broadcast center transmitting signals over a first communications network, a gaming system residing within the central broadcast center, and users who access the gaming system via the first communication network. The gaming system provides a plurality of games that incorporate a scoring protocol that provides real time scoring data transmitting from the plurality of users back to the gaming system via a second communication network. The plurality of users may review the real time scoring data via the first communications network.
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This was made with Government support under DAAL 03-86-C-0022 awarded by U.S. Army Research Office. The government has certain rights in this invention.
This application is a division of application Ser. No. 07/370,667, filed Jul. 23, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a vibration detector for a rotating shaft, and more particularly, to such a detector used with a Czochralski-type crystal puller.
In the Czochralski-type crystal puller, a melt of the crystal material is disposed in a heated crucible, which is attached to a rotating shaft. Surrounding the heater is an insulating jacket called "heater furniture", and the whole apparatus is mounted on a baseplate. A seed crystal is placed in the melt and pulled up, and some of the melt solidifies on the seed in crystallographic alignment therewith. This solidified portion is called the "boule". When the crystal to be formed is GaAs, a very high pressure inert gas must be used to prevent the As from vaporizing. The high pressure causes the gas to be a good thermal conductor. To prevent loss of heat through the gas, which would occur if the gas goes between the heater furniture and the crucible, tight tolerances are used between the rotating crucible and the heater furniture, in particular an insulating cap thereof. However, then the crucible will sometimes make contact with the cap. If the contact is hard enough, it will cause the crucible to break out into a rotary oscillation. This oscillation can cause failure to gain control of crystal growth, and therefore termination of the pull with shorter than desired crystal length, twinning or dislocations in the crystal before the desired length is achieved, and breaking of the boule off the seed and its falling into melt. If boule breakage occurs, it can fracture the crucible. This often causes catastrophic damage to the puller, and since the leaking melt is conductive and hot, this can result in a destroyed heater and even a partially melted baseplate. Further, all items that come in contact with the melt (except the crucible) become contaminated waste.
Presently it can only be determined if the crucible is in a rotational oscillation by observing it on a video monitor. This is dependent on sufficient heat in the crystal chamber to adequately light the crucible, e.g., at least about 4 hours after start of heat-up. It is also necessary to have an operator present at the time of the oscillation and act promptly (typically within a few seconds) to correct it.
It is therefore an object of the present invention to have a warning system for vibration of rotating shaft that provides clear and early warning of the vibration.
SUMMARY OF THE INVENTION
Apparatus in accordance with the invention for detecting vibration of a shaft comprises at least a first non-contacting proximity sensor adapted to be disposed proximate the shaft; filtering means coupled to said sensor; and AC detection means coupled to said filtering means.
A method in accordance with the invention for detecting vibration of a shaft comprises sensing vibration in the shaft without contacting the shaft to provide a sensor signal; filtering said sensor signal; and AC detecting the filtered signal.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a partly cross-sectional and partly block diagram of the apparatus in accordance with the invention;
FIG. 2 shows a detail of a block used in FIG. 1; and
FIG. 3 shows a strip recorder output graph.
DETAILED DESCRIPTION
As shown in FIG. 1 a crucible puller apparatus, generally designated 10, is largely conventional and can be Model 358 made by Cambridge Instruments, Cambridge, U.K., and thus will be only briefly described. A cylindrical sidewall 11 overlies a base plate 12 to form with a top (not shown) a pressure chamber. Plate 12 has a drive shaft 14 extending therethrough that is driven at its bottom end by drive apparatus 16. Apparatus 16 comprises both a motor (not shown) for rotation of shaft 14 and another motor and worm gear (neither shown) for vertical linear motion of shaft 14. Coupled to the upper end of shaft 14 is crucible support rod hardware 18, which in turn supports a graphite crucible holder 20. Disposed within holder 20 is a BNO 3 crucible 22 of between about 0.015 to 0.020 inches (0.0381 to 0.0508 cm) thickness. Disposed around crucible holder 20 is an electrical resistance heater 24, while disposed around heater 24 is heater furniture 26 comprising alternating layers of graphite and graphite blankets. An insulating furniture cap 28 overlies heater furniture 26 and is considered a portion thereof. The clearance gap 90 between cap 28 and holder 20 is very small to prevent an inert gas (not shown), e.g., Ar, N 2 , etc., at very high pressure from flowing therebetween and causing loss of heat. This inert gas is used at a high pressure to prevent vaporization of product reagents, e.g., Ga, As, etc. Within crucible 20 is a melt 30 of a semiconductor material, e.g., GaAs, while above melt 30 is a protective layer 32 of, e.g., B 2 O, to prevent contamination of melt 30 by any O 2 that may be present in the chamber. A seed crystal 34 of the product to be grown, e.g., GaAs, has grown from it a boule crystal 36.
In operation, the seed crystal 34 is rotated and simultaneously pulled up by apparatus (not shown) as the boule crystal 36 grows, which tends to lower the top level of melt 30. Simultaneously, apparatus 16 rotates drive shaft 14 in the opposite direction from that of crystals 34 and 36 and moves it up. This upward movement is to keep the top level of melt 30 at a constant level relative to heater 24, which has been found to be critical for good monocrystalline growth. However, due to the very small gap 90 between cap 28 and holder 20, binding can occur therebetween and hence eventually oscillation of drive shaft 14, with the negative results described above, e.g., damage to the crucible, the crystal, and the puller.
In accordance with the invention, two non-contacting proximity transducer probes 40 and 42 are located around drive shaft 14 just below base plate 12. Sensors or probes 40 and 42 can be of the eddy current type, i.e., coils, such as the 7200 series made by Bentley-Nevada Corp., Minden, Nev., or model KD 2400 made by Kaman Instrumentation Corp., Colorado Springs, Colo. Other types of non-contacting sensors, e.g., hysteresis, capacitance, photoranging, etc., can be used. In general, non-contacting sensors are used to limit motion pick up to that of shaft 14, and their output signals require less filtering and signal analysis to determine shaft abnormalities. Non-contacting sensors provide a DC output signal with a nominal AC component when shaft 14 is just rotating, and an additional AC signal when shaft 14 is also vibrating. The output signals from sensors 40 and 42 are applied to a signal conditioner 43 (described below).
As shown in FIG. 2, transducer sensors 40 and 42 are preferably disposed at a 90 degree angle with respect to one another. If there is binding between cap 28 and holder 20, there will be no change in the output signal from that transducer sensor which is at an angle of about 0 or 180 degrees from the binding point. Thus the 90 degree arrangement ensures an output signal from at least one transducer sensor. If desired, three or more transducer sensors at mutually equal angles can be used, or a single transducer sensor can be used to pick up vibrations, but it will not reliably pick up touching.
The analog signals from transducer sensors 40 and 42 are respectively applied to transducers 40a and 42a and then passed through one Hz high-pass cut off frequency filters 44 and 46, respectively, and are summed together in adder 48. In a particular embodiment, each of the filters 44 and 46 comprises a series input capacitor and the shunt input resistance of adder 48, and an additional two pole high pass filter with a 1 Hz cut off frequency in adder 48 for a total of three poles of high pass filtering. The filters 44 and 46 are used to eliminate the 0 to 30 RPM (DC to 0.5 Hz) normal noise of rotating drive shaft 14. The resulting signal from adder 48 is passed through a low-pass filter 50 of approximately 500 Hz cutoff to eliminate shaft pressure seal noise at a frequency of about 1.2 KHz caused by sequential stick and slip. In a particular embodiment, filter 50 comprises a 6 pole active modified Bessel filter for good pulse response. Details of designing such a filter can be found in "Transducer Interfacing Handbook" by Analog Devices Co., Norwood, Mass. This high frequency stick and slip does not cause the damage that the above described binding does because its frequency is well above the resonant frequency of the entire pulling apparatus. Further, a narrower pass band has been found sometimes useful, e.g., 70 to 200 Hz, and more particularly, 100 to 130 Hz. The lower of these frequencies can be used in the filters 44 and 46, while the higher of these frequencies can be used in filter 50. It will be appreciated that filters 44 and 50, and also 46 and 50, comprise a band pass filtering means. If desired, the output signals from transducers 40a and 42a can be directly added and the added signal passed through a band pass filter with the lower and upper cut off frequencies given above.
The output signal from filter 50 is then full wave rectified by AC detector or rectifier 52. A full wave rectifier is preferably used so that motion of shaft 14 in either direction can be detected although other types of rectifiers can be used. In a particular embodiment, rectifier 52 was an active rectifier. The output signal from rectifier 52 is a D.C. representation of crucible behavior and is applied to a peak detector 54 and from it to a chart recorder (not shown) for display. In a particular embodiment, wherein the chart recorder had a bandwith of 3 Hz, peak detector 54 had a time constant of 10 seconds. However, if the chart recorder has a wider bandwidth, then a lower time constant can be used. Further, peak detector 54 was of the active type.
The output signal from rectifier 52 is also applied to an alarm circuit 56. Low level D.C. (approximately 50 mv) from rectifier 52 represents normal crucible activity. Rapid increases in D.C. level are indications of abnormal crucible behavior. In the alarm circuit 56, if the full wave rectified D.C. voltage exceeds a preset trip point value determined by a potentiometer 58, a retriggerable monostabile multivibrator on-shot therein (not shown), turns on a resettable audible alarm 60 and light 62. If the fault was caused by a momentary contact, the alarm will sound for approximately one second, but the light will stay on until the operator resets it. In the event of a crucible oscillation, the alarm 60 and light indicator 62 will remain on until the fault, i.e., oscillation, is cleared and/or a reset switch (not shown) in alarm 56 has been pressed.
FIG. 3 shows a chart recorder output calibrated in 24 hour time. Up to about 0930 there is no binding. This is due to an initial alignment that is performed before the puller starts operation. After 0930 some binding takes place as indicated by spikes 70. As time passes, the spikes become larger with a particularly large spike 72 at 1300, thus indicating that the binding is becoming harder. After 1330, several large spikes 74 occur with a generally increasing amplitude. Finally, at about 1415, a very large continuous oscillation 76 occurs. An operator observing the oscillation 76 can clear the incipient fault by slowing down the rotation of shaft 14 and then bring it back up to normal rotational speed to resume the normal growth rate of boule 36. Usually when bringing shaft 14 back up to normal speed, the oscillation will not reoccur because the binding caused by grinding of cap 28 and/or holder 20 increases the tolerance therebetween.
It will be appreciated the many other embodiments are possible within the spirit and scope of the invention. For example, an AC detector, such as an AC voltmeter, can be coupled to the output of filter 50, or even directly to the output of adder 48, and the needle or digits of the voltmeter watched by the operator for a rising average value. This eliminates the need for elements 50 to 62 of FIG. 2.
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Apparatus for detecting abnormal vibration in a shaft, such as a rotating crucible holder drive shaft of a crystal puller, has a pair of sensors disposed 90 degrees with respect to each other. The signals are high pass filtered and added together, then low pass filtered and full wave rectified to operate an alarm and strip recorder. A method for detecting vibration in a shaft comprises sensing vibrations in the shaft, filtering the sensed signals, and rectifying the filtered signals.
| 8
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TECHNICAL FIELD
[0001] The present invention relates to a process for manufacturing reduced iron agglomerates by charging compacts composed of a raw-material mixture that contains an iron oxide-containing material and a carbonaceous reducing agent onto a hearth of a moving-bed heating furnace and heating the compacts to subject iron oxide in the compacts to reduction or reduction-melting.
BACKGROUND ART
[0002] A direct reduction ironmaking process for the manufacture of agglomerative (including granular) metallic iron (reduced iron) from a mixture containing an iron-oxide source (hereinafter, also referred to as an “iron oxide-containing material”), for example, iron ore or iron oxide, and a carbon-containing reducing agent (hereinafter, also referred to as a “carbonaceous reducing agent”) has been developed. In this ironmaking process, compacts into which the mixture is formed are charged onto a hearth of a moving-bed heating furnace. The compacts are heated in the furnace by gas heat transfer and radiant heat with a heating burner to reduce iron oxide in the compacts with carbonaceous reducing agent. Subsequently, the resulting reduced iron is carburized, melted, and coalesced into agglomerates while being separated from by-product slag. Then the agglomerates are cooled and solidified to provide agglomerative metallic iron (reduced iron agglomerates).
[0003] Such an ironmaking process does not require a large-scale facility, such as a blast furnace, and has a high degree of flexibility in resources, for example, no need for coke; hence, the ironmaking process have recently been studied to achieve practical use. To perform it on an industrial scale, however, there are many problems regarding, for example, stable operation, safety, cost, the quality of granular iron (product), productivity to be solved.
[0004] In particular, in order to manufacture reduced iron agglomerates, it is desirable to improve the yield of large-grain reduced iron agglomerates and a reduction in manufacturing time. Regarding such a technique, for example, PTL 1 reports that “a method for manufacturing granular metallic iron includes heating a raw material that contains an iron oxide-containing material and a carbonaceous reductant to reduce a metal oxide in the raw material, further heating the resulting metal to melt the metal, and allowing the metal to coalesce to form a granular metal while being separated from a by-product slag component, in which a coalescence-promoting agent for the by-product slag is compounded in the raw material”.
[0005] In this technique, a large-grain granular metal should be manufactured in a high yield to some extent by compounding the coalescence-promoting agent (for example, fluorite). However, also in such a technique, the improvement effect is saturated, so further improvement of the effect is desired.
[0006] Regarding the quality of the reduced iron agglomerates, the granular iron manufactured by the foregoing ironmaking method is fed to an existing steelmaking facility and used as an iron source. Thus, the granular iron desirably has a low content of impurity elements, such as sulfur. As a technique therefor, for example, PTL 2 reports that “a method for manufacturing granular metallic iron having a low sulfur content includes charging a mixture that contains a metal oxide-containing substance and a carbonaceous reductant onto a hearth of a moving-bed heating furnace, heating the mixture to reduce iron oxide in the mixture with the carbonaceous reductant, allowing the metallic iron formed to coalesce into granules while the metallic iron is separated from a by-product slag, and solidifying the granules by cooling, in which the amounts of CaO, MgO, and SiO 2 -containing substances in the mixture are adjusted in such a manner that the basicity of slag components, i.e., (CaO+MgO)/SiO 2 , is in the range of 1.2 to 2.3 and that the content of MgO (MgO) in the components contained in the slag is in the range of 5% to 13%, determined from the contents of CaO, MgO, and SiO 2 in the mixture”.
[0007] In this technique, a MgO-containing substance (for example, dolomite ore) is added to the mixture to adjust the slag components, thereby providing granular metallic iron having a low sulfur content. Also in this technique, the improvement effect is saturated, so further improvement of the effect is desired.
[0008] Note that the coalescence-promoting agent, such as fluorite, and the MgO-containing substance, such as dolomite ore, are both commonly used as melting-point-adjusting agents.
CITATION LIST
Patent Literature
[0000]
PTL 1: Japanese Unexamined Patent Application Publication No. 2003-73722
PTL 2: Japanese Unexamined Patent Application Publication No. 2003-285399
SUMMARY OF INVENTION
Technical Problem
[0011] The present invention has been accomplished in light of the foregoing circumstances. It is an object of the present invention to provide a process for manufacturing reduced iron agglomerates by heating compacts composed of a raw-material mixture that contains at least an iron oxide-containing material and a carbonaceous reducing agent with a moving-bed heating apparatus to subject the iron oxide in the compacts to reduction-melting, the process being such that the yield of the reduced iron agglomerates having large grain size is improved, the productivity is improved by a reduction in manufacturing time, and the content of impurity elements, such as sulfur, in the reduced iron agglomerates is minimized.
Solution to Problem
[0012] A process for manufacturing reduced iron agglomerates according to the present invention that solves the foregoing problems includes charging compacts that contain an iron oxide-containing material and a carbonaceous reducing agent onto a hearth of a moving-bed heating furnace, and heating the compacts to reduce iron oxide in the compacts, in which each of the compacts that contains the iron oxide-containing material having a mean particle diameter of 4 to 23 μm and containing particles with a particle diameter of 10 μm or less in a proportion of 18% by mass or more is used.
[0013] In the process according to the present invention, as the iron oxide-containing material, a specific example is iron ore. The iron oxide-containing material located in the central portion of each of the compacts preferably has a mean particle diameter of 4 to 23 μm.
[0014] Another process for manufacturing reduced iron agglomerates according to the present invention that solves the foregoing problems includes charging compacts that contain an iron oxide-containing material, a carbonaceous reducing agent, and a melting-point-adjusting agent onto a hearth of a moving-bed heating furnace, heating the compacts to reduce iron oxide in the compacts, further heating the compacts to at least partially melt the compacts, and coalescing an iron component, in which each of the compacts that contains the iron oxide-containing material having a mean particle diameter of 4 to 23 μm and containing particles with a particle diameter of 10 μm or less in a proportion of 18% by mass or more is used.
[0015] Also in this process, as the iron oxide-containing material, a specific example is iron ore. The iron oxide-containing material located in the central portion of each of the compacts preferably has a mean particle diameter of 4 to 23 μm.
Advantageous Effects of Invention
[0016] According to the present invention, compacts composed of a raw-material mixture that contains at least an iron oxide-containing material and a carbonaceous reducing agent are charged onto a hearth of a moving-bed heating furnace, and heated to subject iron oxide in the compacts to reduction-melting, thereby providing reduced iron agglomerates. The mean particle diameter and the particle size distribution of the iron oxide-containing material are appropriately controlled, thereby improving the yield of the reduced iron agglomerates having large grain size, reducing the manufacturing time to improve the productivity, and minimizing the contents of impurity elements, such as sulfur, in the reduced iron agglomerates.
DESCRIPTION OF EMBODIMENTS
[0017] In the case where reduced iron agglomerates are manufactured, when compacts composed of a mixture that contains an iron oxide-containing material serving as a raw-material component and a carbonaceous reducing agent are formed, each of the iron oxide-containing material and the carbonaceous reducing agent is appropriately pulverized and then is adjusted so as to have uniform size in order to easily granulate them. However, the influence of the size of the raw-material component (mean particle diameter) on the yield and productivity of the reduced iron agglomerates has not been considered. It has been believed that excessive pulverization of the raw-material component leads to the dispersion of the raw-material component, thereby preventing the coalescence of reduced iron to decrease the productivity.
[0018] To achieve the foregoing object, the inventors have conducted studies from a variety of perspectives. In particular, the inventors have conducted studies on the influence of the particle diameter and the particle size distribution of the raw-material component on the productivity and have found that appropriate adjustment of the mean particle diameter and the particle size distribution of an iron oxide-containing material successfully achieves the foregoing object. The findings have led to the completion of the present invention.
[0019] In the present invention, the iron oxide-containing material in the agglomerates needs to have a mean particle diameter of 23 μm or less and contain particles having a particle diameter of 10 μm or less in a proportion of 18% by mass or more. The term “mean particle diameter” used here indicates a particle diameter (hereinafter, also referred to as “D50”) corresponding to 50% by mass (an accumulated value of 50% by mass) when the number of particles is counted from the smallest particle. The reason for the improvement in the yield of the reduced iron agglomerates and the productivity by the use of the fine raw-material component is speculated as follows.
[0020] The foregoing compacts are subjected to reduction or reduction-melting at 1200° C. to 1500° C. In the early stage of the reduction reaction, the direct contact between the iron oxide-containing material and the carbonaceous reducing agent permits the reaction to proceed. The pulverization of the iron oxide-containing material into fine particles increases the opportunity for the contact between the iron oxide-containing material and the carbonaceous reducing agent, thus decreasing the reduction time. When the carbonaceous reducing agent begins to gasify, the reduction reaction proceeds from a surface of the iron oxide-containing material. Thus, the pulverization of the iron oxide-containing material into fine particles increases the surface area and decreases the reduction time and the manufacturing time of the reduced iron agglomerates (hereinafter, the reduced iron agglomerates produced by reduction-melting is also referred to particularly as “granular reduced iron”).
[0021] As the raw-material component used in the present invention, a melting-point-adjusting agent, for example, limestone, fluorite, or dolomite ore, may be contained. In this case, the pulverization of the iron oxide-containing material into fine particles shortens the distance between a gangue component in the iron oxide-containing material and a surface of the melting-point-adjusting agent (increases the probability that the gangue component in the iron oxide-containing material is present close to the surface of the melting-point-adjusting agent) and increases the frequency of the contact between the gangue component and the melting-point-adjusting agent, thereby facilitating the formation of a molten product. This promotes the separation of the gangue from the iron oxide-containing material and the coalescence of the reduced iron oxide component. That is, a phenomenon completely opposite to knowledge recognized in the past may occur.
[0022] A sulfur component is mainly contained in the carbonaceous reducing agent. After the gasification of the carbonaceous reducing agent, the sulfur component is left in pellets. The sulfur component is incorporated into the granular reduced iron and a molten gangue component during melting. In the present invention, the molten gangue component is easily formed. Thus, the sulfur component is more likely to be smoothly and rapidly incorporated into the molten component and is less likely to be incorporated into the granular reduced iron, thus seemingly reducing the sulfur concentration in the granular reduced iron.
[0023] To efficiently provide the effect, the iron oxide-containing material needs to have a mean particle diameter (D50) of 23 μm or less and contain particles having a particle diameter of 10 μm or less in a proportion of 18% by mass or more. The mean particle diameter is preferably 17 μm or less. If the mean particle diameter (D50) is less than 4 μm, which is excessively small, it is difficult to form the compacts.
[0024] As the iron oxide-containing material used in the present invention, iron ore, iron sand, nonferrous smelting residues, or the like may be used. As the carbonaceous reducing agent, a carbon-containing material may be used. For example, coal or coke may be used.
[0025] As additional components, a binder, a MgO supply material, a CaO supply material, and so forth may be incorporated into the foregoing compacts. Examples of the binder that may be used include polysaccharides (for example, starch, such as flour). Examples of the MgO supply material that may be used include MgO powders, Mg-containing materials extracted from natural ore and seawater, and magnesium carbonate (MgCO 3 ). Examples of the CaO supply material that may be used include quick lime (CaO), slaked lime (Ca(OH) 2 ), and limestone (main component: CaCO 3 ). In addition, dolomite, which is a double salt of calcium carbonate and magnesium carbonate, may be used.
[0026] The shape of the compacts is not particularly limited. Examples thereof include pellets and briquettes. The size of the compacts is not particularly limited. The diameter (maximum diameter) is preferably 50 mm or less. If the diameter of the compacts is excessively large, the agglomeration efficiency is reduced. Moreover, the heat transfer to lower portions of the pellets is reduced, thereby reducing the productivity. The lower limit of the size is about 5 mm.
[0027] Not all of the iron oxide-containing material particles in the compacts are required to be pulverized. Ten percent by mass or more of the entire iron oxide-containing material may satisfy the foregoing requirement for the mean particle diameter. An example of a structure that satisfies the requirement is a structure in which the pulverized iron oxide-containing material is present only in at least the central portion of each of the compacts. When the compacts are heated from the outside, a rise in the temperature of the central portion of each compact is delayed, compared with the peripheral portion. Thus, the reaction is also delayed. To relax the phenomenon, it is effective to arrange the pulverized iron oxide-containing material in the central portion. The term “central portion” indicates that, for example, if the compacts have a spherical shape (dry pellet described below), the central portion refers to a portion extending from the center of a sphere to a position that satisfies the foregoing mean particle diameter of the fine particles (a portion outside the portion is defined as a “peripheral portion”).
[0028] In the case where the pulverized iron oxide-containing material is present in at least the central portion of each of the compacts, a basic structure is as follows: the pulverized iron oxide-containing material specified in the present invention is present only in the central portion, and the raw-material component having a normal mean particle diameter (not pulverized) is present in the peripheral portion. Furthermore, an embodiment of the present invention includes a structure in which all the raw-material component used is the iron oxide-containing material that satisfies the mean particle diameter and the particle size distribution specified in the present invention.
[0029] This application claims the benefit of priority of Japanese Patent Application No. 2012-042395 filed Feb. 28, 2012. Japanese Patent Application No. 2012-042395 filed Feb. 28, 2012 is hereby incorporated by reference herein in its entirety.
EXAMPLES
[0030] The present invention will now be further described in detail with reference to examples, but it should be understood that the examples are not intended to limit the present invention. Any modification in the range of the purpose described above or below is within the technical scope of the present invention.
Example 1
[0031] Compacts composed of a raw-material mixture containing an iron oxide-containing material, a carbonaceous reducing agent, and a binder were produced. The compacts were charged into a heating furnace and heated to subject iron oxide in the compacts to reduction-melting, thereby producing reduced iron agglomerates (granular reduced iron).
[0032] In this case, iron ore A having a component composition (composition of main components) described in Table 1 was used as the oxide-containing material. Coal having a component composition described in Table 2 was used as the carbonaceous reducing agent. The compacts were produced with the raw-material components (the iron oxide-containing material and the carbonaceous reducing agent) having different mean particle diameters and different particle size distributions. Specifically, flour serving as the binder was blended with mixtures of iron ore and coal having different mean particle diameters (D50) in a blending ratio described in Table 3. Cylindrical compacts each having a diameter of 20 mm and a height of 10 mm (after the formation, drying was performed at 105° C. for a whole day and night) were produced.
[0000]
TABLE 1
Component composition of
Type of iron
iron ore (% by mass)
ore
T. Fe
FeO
SiO 2
CaO
Al 2 O 3
MgO
S
A
66.62
0.12
2.24
0.07
0.96
0.03
0.008
B
67.61
29.14
4.9
0.45
0.23
0.49
0.003
[0000]
TABLE 2
Component composition of coal (% by mass)
Fixed carbon
Volatile component
Ash
Total
84.36
7.58
8.06
100
[0000]
TABLE 3
Blending ratio (% by mass)
Iron ore
Coal
Binder
Total
79.24
19.86
0.9
100
[0033] The compacts were heated at 1300° C. in a nitrogen atmosphere, and the reduction rate (reaction time) was studied. The reaction time was evaluated by the time required for the rate of reduction of the iron oxide component in the iron ore to reach 90%. Table 4 describes the results together with the mean particle diameters and the particle size distributions of the raw-material components (iron ore and coal) used.
[0000]
TABLE 4
Content of parti-
cles with particle
Mean particle
diameters of 10
Mean particle
Experi-
diameter of
μm or less in
diameter
Reaction
ment
iron ore
iron ore A
of coal
time
No.
(μm)
(% by mass)
(μm)
(min)
1
37
6
48
9.3
2
17
32
48
8.8
3
3.9
99
48
7.7
4
37
6
14
9.1
5
37
6
2.4
9.0
6
17
32
14
8.4
[0034] The results demonstrate that a smaller mean particle diameter (D50) of the iron ore results in a significant reduction in reaction time. Although an attempt was made to form a compact from iron ore having a mean particle diameter (D50) less than 4 μm, it was found that the formation was impossible.
Example 2
[0035] Compacts composed of a raw-material mixture containing an iron oxide-containing material, a carbonaceous reducing agent, melting-point-adjusting agents (limestone, dolomite, and fluorite), and a binder were produced. The compacts were charged into a heating furnace and heated to subject iron oxide in the compacts to reduction-melting, thereby producing reduced iron agglomerates.
[0036] In this case, iron ores having component compositions described in Table 1 were used as the oxide-containing material. Coal having a component composition described in Table 5 was used as the carbonaceous reducing agent. As the melting-point-adjusting agents, limestone having a component composition (composition of main components) described in Table 6, dolomite having a component composition (composition of main components) described in Table 7, and fluorite having a component composition (composition of main components) described in Table 8 were used. The compacts were produced with iron ores having different mean particle diameters and different particle size distributions (content of particles with a predetermined particle diameter). Specifically, flour serving as the binder was blended with mixtures iron ores having different mean particle diameters and different particle size distributions in a blending ratio described in Table 9. An appropriate amount of water was added to each of the resulting mixtures. The mixtures were agglomerated with a tire-type pelletizer into green pellets having a diameter of 19 mm. The resulting green pellets were charged into a dryer and heated at 180° C. for 1 hour to completely remove adhesion water, thereby providing pellet-shaped agglomerates (spherical dry pellets).
[0000]
TABLE 5
Component composition of coal (% by mass)
Fixed carbon
Volatile component
Ash
Total
79.5
15.97
4.53
100
[0000]
TABLE 6
Component composition of limestone (% by mass)
SiO 2
CaO
Al 2 O 3
MgO
S
0.14
56.87
<0.01
0.14
<0.001
[0000]
TABLE 7
Component composition of dolomite (% by mass)
SiO 2
CaO
Al 2 O 3
MgO
S
2.0
35.71
0.27
16.85
<0.001
[0000]
TABLE 8
Component composition of fluorite (% by mass)
SiO 2
T. Ca
Al 2 O 3
MgO
F
3.05
50.39
0.28
<0.01
47.54
[0000]
TABLE 9
Pattern of
Blending ratio (% by mass)
blending
Iron
Lime-
ratio
ore
Coal
stone
Dolomite
Fluorite
Binder
Total
a
75.04
18.0
1.95
3.31
0.8
0.9
100
b
71.32
16.83
7.27
2.88
0.8
0.9
100
[0037] The dry pellets were charged into a heating furnace in which a carbon material (anthracite having a maximum particle diameter of 2 mm or less) was placed. The dry pellets were heated at 1450° C. in a nitrogen atmosphere, and the time (reaction time) required for reduction-melting was studied.
[0038] Table 10 describes the results together with the mean particle diameters of the raw-material components used (iron ores, coal, limestone, dolomite, and fluorite) and the contents of particles with particle diameters of 10 μm or less in the iron ores (contents of particles with particle diameters of 10 μm or less). Table 10 also describes the general properties of the dry pellets (for example, the apparent density and the analytical value of the dry pellets) (mean value of 10 pellets for each experiment). Among the items described in Table 10, measurement methods and criteria for main items are described below.
[Sulfur Partition]
[0039] The ratio of the amount of sulfur [S] in the reduced iron agglomerates to the amount of sulfur (S) in the component composition of slag (by-product slag formed when granular reduced iron is formed) ([S]/(S), sulfur partition) was calculated. The sulfur partition serves as an index of the sulfur content of granular reduced iron. [Productivity (productivity index)]
[0040] The productivity when the dry pellets were heated to subject the metal oxide to reduction-melting for the production of reduced iron agglomerates was evaluated by the amount (ton) of reduced iron agglomerates produced per unit time (hour) per hearth area (m 2 ) as represented by the following expression (1):
[0000] Productivity (ton/m 2 /hour)=productivity of granular reduced iron (ton/hour)/hearth area (m 2 ) (1)
[0041] In the expression (1), the productivity of the granular reduced iron (ton/hour) is represented by the following expression (2):
[0000] Productivity of granular reduced iron (granular reduced iron ton/hour)=amount of compact(dry pellet)charged (compact ton/hour)×mass of granular reduced iron produced per ton of compact (granular reduced iron ton/compact ton)×product recovery ratio (2)
[0042] In the expression (2), the product recovery ratio is calculated from the ratio of the mass of the granular reduced iron having a diameter of 3.35 mm or more with respect to the total amount of the resulting granular reduced iron to the total amount of the granular reduced iron [(granular iron having a diameter of 3.35 mm or more (% by mass)/total weight of granular reduced iron (%))×100(%)] (expressed as “yield of granular iron with particle diameter of 3.35 mm or more (%)” in Table 10). In Table 10, in order to quantitatively evaluate the effect of the present invention, the compacts (dry pellets) in Experiment No. 7 are defined as reference compacts, the productivity when the reference compacts are used is defined as 1.00, and the productivity when these compacts are used is expressed as a relative value (productivity index).
[0000]
TABLE 10
Experiment No.
7
8
9
10
11
12
Type of iron ore
A
A
A
A
A
B
Mean particle diameter (D50) of
raw material
Iron ore (μm)
37
17
17
4
37
23
Coal (μm)
21
11
21
21
11
11
Limestone (μm)
11
4
11
11
11
11
Dolomite (μm)
56
3.0
56
56
56
56
Fluorite (μm)
25
5
25
25
25
25
Content of particle with particle
6
32
32
99
6
18
diameter of 10 μm or less in iron
ore (% by mass)
Raw-material blend
a
a
a
a
a
b
Dry pellet
Apparent density (g/cm 3 )
2.200
2.273
2.272
2.257
2.209
2.281
Reaction time (min)
10.42
9.44
10.40
9.16
10.64
9.57
Analytical value of dry pellet
Total iron (%)
50.31
50.29
50.29
50.29
50.41
48.35
Granular reduced iron
82.47
99.51
100.66
102.44
82.08
103.3
Yield of granular iron with
particle diameter of 3.35 mm or
more (%)
Analytical value of granular
reduced iron
S (%)
0.066
0.051
0.050
0.041
0.067
0.022
Analytical value of slag
S (%)
1.04
1.01
1.02
0.99
1.03
0.84
Sulfur partition (—)
15.8
19.8
20.4
24.0
15.4
38.18
Productivity index (—)
1.00
1.38
1.26
1.45
0.98
1.36
[0043] The results demonstrate that in the case where the iron ore has a mean particle diameter (D50) of 23 μm or less and where it contains particles having a particle diameter of 10 μm or less in a proportion of 18% by mass or more, the yield of the granular reduced iron is improved, thus significantly improving the productivity. The results also demonstrate that the amount of sulfur in the granular reduced iron is reduced. Also in Example 2, although an attempt was made to form a compact from iron ore having a mean particle diameter (D50) less than 4 μm, it was found that the formation was impossible.
Example 3
[0044] Dual-structured dry pellets were produced with mixtures each containing the iron oxide-containing material having the same component composition as used in Example 2 (type of iron ore: A), a carbonaceous reducing agent, a melting-point-adjusting agents (limestone, dolomite, and fluorite), and a binder (regarding the blending ratio, the same blending pattern as that described in a of Table 9 was used). Specifically, flour serving as a binder was mixed with a mixture containing iron ore having a mean particle diameter described in “Central portion” of Table 11. An appropriate amount of water was added to the resulting mixture. The mixture was agglomerated into spherical pellets having a diameter of 9.5 mm with a tire-type pelletizer. These pellets were used as cores. A mixture containing the raw-material component having a different mean particle diameter was formed concentrically around each of the cores (peripheral portions) into green pellets having a diameter of 19.0 mm (the content of the mixture in the central portion was about 12% by mass with respect to the entire pellet). The resulting green pellets were charged into a dryer and heated at 180° C. for 1 hour to completely remove adhesion water, thereby providing pellet-shaped agglomerates (dual-structured pellets).
[0045] The dual-structured pellets were charged into a heating furnace in which a carbon material (anthracite having a maximum particle diameter of 2 mm or less) was placed. The dual-structured pellets were heated at 1450° C. in a nitrogen atmosphere, and the reduction rate (reaction time) was evaluated in the same way as in Example 2. Table 11 describes the results together with the mean particle diameters (D50) of the raw-material components used (iron ore, coal, limestone, dolomite, and fluorite). Table 11 also describes the items evaluated in Example 2 (by the same evaluation methods as in Example 2).
[0000]
TABLE 11
Experiment No.
13
Position
Central portion
Peripheral portion
Type of iron ore
A
A
Mean particle diameter (D50) of
raw material
Iron ore (μm)
17
37
Coal (μm)
21
21
Limestone (μm)
11
11
Dolomite (μm)
56
56
Fluorite (μm)
25
25
Raw-material blend
a
a
Dry pellet
Apparent density (g/cm 3 )
2.265
Reaction time (min)
11.4
Analytical value of dry pellet
Total iron (%)
50.61
Granular reduced iron
Yield of granular iron with particle
89.45
diameter of 3.35 mm or more (%)
Analytical value of granular reduced
iron
S (%)
0.06
Analytical value of slag
S (%)
1.06
Sulfur partition (—)
17.7
Productivity index (—)
1.03
[0046] The results demonstrate that even when only the central portion is particularly formed of the fine particles without using the fine particles for the entire pellet, the effect of improving the yield of the granular reduced iron is provided, and the sulfur partition is also improved. As described above, the results demonstrate that in the case where only the central portion is particularly formed of the fine particles, even in a state in which a smaller amount of the fine particles of the raw-material component is used, the effect of the present invention is provided.
INDUSTRIAL APPLICABILITY
[0047] The present invention provides a process for manufacturing reduced iron agglomerates, in which the process includes charging compacts that contain an iron oxide-containing material and a carbonaceous reducing agent onto a hearth of a moving-bed heating furnace and heating the compacts to reduce iron oxide in the compacts. The use of the compacts containing the iron oxide-containing material which has a mean particle diameter of 4 to 23 μm and which contains particles with a particle diameter of 10 μm or less in a proportion of 18% by mass or more improves the yield of the reduced iron agglomerates having large grain size, reduces the manufacturing time to improve the productivity, and minimizes the contents of impurity elements, such as sulfur, in the reduced iron agglomerates.
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A process for manufacturing reduced iron agglomerates which comprises introducing starting agglomerates that comprise both an iron oxide-containing material and a carbonaceous reducing agent onto the hearth of a moving-bed heating furnace, and heating the agglomerates to reduce the iron oxide contained in the agglomerates, wherein the iron oxide-containing material contained in the starting agglomerates has a mean particle diameter of 4 to 23 μm and contains at least 18% of particles having diameters of 10 μm or less. By the use of such starting agglomerates, the process attains: an improvement in the yield of reduced iron agglomerates having large particle diameters; a reduction in the manufacturing time, said reduction leading to an enhancement in the productivity; and a remarkable reduction in the content of impurities such as sulfur in the reduced-iron agglomerates.
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BACKGROUND OF THE INVENTION
This invention relates generally to the field of underwater mine countermeasure warfare, and more particularly to an underwater mine countermeasure warfare system utilizing an air cushion vehicle equipped with a magnetic sweep generator capable of emitting a magnetic field pattern for exploding submerged mines having magnetic field responsive detonators.
It has long been well known in the field of both land and sea warfare to set mines in strategic locations which will explode at an appropriate moment to destroy vehicles and land vehicles which are within the explosive range of the mines. In addition to mere contact between a vehicle and a mine, various techniques have been developed to cause the mines to explode remotely so that the vehicle suffers damage without actually contacting the mine. For example, some mines are provided with acoustically responsive detonators which cause the mines to explode when the detonator detects a predetermined sound wave pattern which simulates the sound pattern of a ship or other vehicle. Another example is mines which are provided with magnetically responsive detonators which cause the mines to explode when the detonator detects a predetermined magnetic field pattern which simulates the magnetic field or signature of an approaching ship. Some mines require a particular orientation and time rate of change of the magnetic field, the acoustic field, or both, before they will explode.
However, with each new technological advance in the sophistication of detonating systems for mines, a countermeasure is soon developed for defeating the effectiveness of a new detonator. This is normally accomplished by devising systems which simulate the condition to which the detonator is responsive so that the mine is caused to explode harmlessly without damage to any nearby vehicles. For example, contact mines can be exploded by dragging various devices along the surface on which the mines are imbedded or floating, as the case may be, by a helicopter. Acoustic mines can be exploded by transmitting a pattern of acoustic waves which simulate the sound pattern of a vehicle or vehicle to which the detonator is responsive, such as the sound pattern emitted by the engines of a ship. Similarly, magnetic mines can be exploded by generating a magnetic field which simulates the magnetic signature of an approaching and or departing vehicle or vehicles. This technique is particularly suitable to exploding underwater mines because large ships emit a distinctive magnetic field pattern because of both the large mass of metal and a variety of equipment which generates various magnetic field patterns. Often mines are designed to explode only after being exposed to a predetermined number of exposures to the critical parameters, which can be conveniently accomplished by an automated system to repetitively generate a field simulating a target ship's approaching or departure pattern.
A major problem with any system for simulating a condition to which a mine is responsive is that of bringing the simulating system into sufficiently close proximity to the mine to cause it to explode without damaging the vehicle used to transport the simulating system. Many solutions to this problem have been put forth from time to time, such as the use of helicopters as mentioned above or slow flying airplanes dragging or towing the condition simulating equipment, and land and sea vehicles equipped with the necessary simulating equipment which can function out of range of the explosive force of the mines.
Prior to the present invention, one solution in particular worked rather effectively as an underwater mine countermeasure system, which is the type of mine warfare with which the present invention is primarily concerned. This solution included a pontoon supported vehicle which could be remotely controlled from another vehicle, and which included apparatus for generating a magnetic field in the water which extended for some considerable distance beyond the vehicle. The magnetic field was generated by a combination of a horizontal loop magnetic coil located on the railing of the vehicle in a plane parallel to the deck of the vehicle. Additionally, four more axial coils were found on two heavy iron pipe cores located in the pontoons of the vehicle. The magnetic field generated by this combination of coils was of sufficient intensity to explode submerged mines having magnetically responsive detonators while the vehicle was still out of range of the explosive force of the mine so that it suffered no damage. Unfortunately, the vehicle could travel at only a moderate speed, thereby impeding its ability to move quickly from one operational location to another; it had very limited maneuverability; and being in the water it was subject to underwater shock from exploding mines and therefore had to be operated at considerable distances from the mines, necessitating very high capacity magnetic field generating equipment.
BRIEF SUMMARY OF THE INVENTION
The present invention substantially alleviates, if not altogether eliminates, the disadvantages of prior known vehicles utilized in mine countermeasure warfare, particular those utilized in underwater mine countermeasure warfare.
The present invention is an underwater mine warfare countermeasure system which includes a water borne vehicle having a platform normally constituting a deck. A magnetic field generating means is mounted on the platform of the vehicle for generating a magnetic field pattern beneath the vehicle which is of sufficient magnitude and extends sufficiently far from the vehicle in all directions to activate a magnetically responsive detonator in a mine while the vehicle remains out of range of the explosive force of the mine.
In the presently preferred embodiment of the invention, the magnetic field generating means comprises a plurality of closed loop magnetic coils mounted on the platform in planes which are substantially horizontally and vertically oriented with respect to the platform of the air cushion vehicle. In particular, one coil is arranged in a substantially horizontal plane and is generally contiguous with the periphery of the platform. Three additional coils are mounted on the platform in upstanding rectangular frames and are spaced apart so as to lie in planes which are substantially perpendicular to the plane of the first coil and are parallel to each other.
Although not essential to the practice of the present invention, it is preferred that the water borne vehicle be of the air cushion type, which has a platform, a blower system mounted on the platform for discharging air into an air chamber located beneath the platform, an air retaining skirt attached to and surrounding the platform for retaining a cushion of air in the air chamber at sufficient pressure to support the vehicle above the surface on which it normally rests, and means mounted on the platform for propelling the vehicle in a given direction when the vehicle is supported by the cushion of air.
Several significant advantages are offered by the use of an air cushion vehicle over a flotation vehicle, whether of single or of multiple hull construction, such as greater maneuverability and speed, and, most importantly, the relative insensitivity of an air cushion vehicle to underwater shock. Relative high speeds in the order of 45 knots afford greatly decreased transit times in relocating from one operational zone to another, and the ability to operate in high seas further adds to the operational flexibility of the vehicle.
One critical operational requirement of an air cushion vehicle is that of avoiding any and all unnecessary weight. Since the vehicle is supported on a cushion of air beneath the platform, the heavier the vehicle becomes, the more difficult it is to generate the pressure required to lift the vehicle from the supporting surface. Thus, as weight is added to a given vehicle, more powerful and larger capacity lift engines and blowers are required to generate the necessary pressure, thereby rendering the vehicle more cumbersome and costly to operate.
In order to obtain full benefit of the advantages of an air cushion vehicle, it is necessary to have a magnetic field generating means which is both light in weight and yet capable of generating the maximum field strength possible. By eliminating the axial coils used in the predecessor vehicle, the heavy iron pipe cores are no longer required, thereby substantially reducing the weight of the improved coil system. In addition, the new coil configuration provides an increased magnetic field intensity due to the area within the rectangular frames, thereby enabling larger ships to be simulated and a wider lane to be swept. In addition, the maintainability of the system is greatly enhanced because all components are either on or above the platform of the vehicle. Further, since the coils can easily be removed, the vehicle is more adaptable for use in alternate missions.
Having briefly described the general nature of the present invention, it is a principal object thereof to provide an underwater mine warfare countermeasure system which effectively alleviates or eliminates the disadvantages of prior known under water mine warfare countermeasure systems, while at the same time retaining the significant advantages thereof.
Another object of the present invention is to provide an underwater mine warfare countermeasure system which utilizes a water borne vehicle, preferably an air cushion vehicle, as the primary support vehicle for a system which explodes submerged mines without damage to the support vehicle.
Still another object of the present invention is to provide an underwater mine warfare countermeasure system in which a magnetic field generating means is provided which is designed to have the least amount of weight possible for the size and strength of the magnetic field generated.
These and other objects and advantages of the invention will become more apparent from an understanding of the following detailed description of a presently preferred embodiment of the invention, when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an air cushion vehicle incorporating the present invention;
FIG. 2 is a plan view of the air cushion vehicle shown in FIG. 1 ;
FIG. 3 is a side view of the air cushion vehicle shown in FIG. 1 ; and
FIG. 4 is an illustration of the manner in which the air cushion vehicle is controlled remotely from a control vehicle, and shows a magnetic wave pattern being generated to explode mines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and particularly to FIGS. 1 through 4 thereof, the invention comprises a remotely controlled air cushion vehicle generally designated by the reference numeral 10 , although as indicated above a flotation type vehicle could be substituted for the air cushion vehicle disclosed. The vehicle 10 is shown somewhat generally for illustrative purposes only and only those details of the vehicle which are necessary to an understanding of the invention are shown and described. Thus, the vehicle 10 comprises a platform 12 supported on a suitable hull 13 which constitutes the main structural hull of the vehicle. A peripheral skirt system 14 consisting of a bag of neoprene-coated nylon fabric is attached to the periphery of the platform 12 and extends downwardly therefrom to form an air chamber (not shown) between the underside of the platform 12 and any surface on which the vehicle is resting or over which it is traveling. The skirt system 14 provides a low drag interface with the surface at all speeds, whether over water, hard surfaces, or marsh, and lifts the vehicle high enough to provide obstacle clearances in rough terrain. It also provides pitch and roll stability to contribute to a good ride and avoid a plow-in condition.
Although several variations exist, the air cushion vehicle also includes a blower system which is designed to blow air downwardly through openings in the platform 12 to create an air cushion in the chamber 16 which has sufficient pressure to raise the vehicle above the surface on which it is resting. Thus, in the illustrated vehicle, a blower assembly 18 is mounted on the platform 12 in any suitable location and is driven by a suitable engine 20 mounted on the platform 12 within the housing 22 so as to blow a large volume of air downwardly, either directly through a large opening in the platform 12 or through an air distribution system within the platform 12 and skirt system 14 which distributes the air more uniformly than does a single large opening.
The vehicle is propelled in a forward direction by one or more propellers 24 mounted on supports 25 adjacent the rear end of the platform 12 , the propellers being driven by any suitable engines 26 located within the housing 28 . A plurality of aerodynamic rudders or vanes 30 are mounted rearwardly of the propellers and are pivotable about a vertical axis so as to direct the air stream from the propellers 22 toward either side of the vehicle for the purpose of steering the vehicle in either left or right directions. Finally, the vehicle 10 is provided with a suitable antenna 32 by which the vehicle 10 receives control signals 34 ( FIG. 4 ) from a remote control vehicle generally designated by the numeral 36 . The control components for operating all of the systems on the air cushion vehicle are located in the housing 38 .
As best seen in FIG. 1 , the magnetic field generating means comprises a plurality of magnetic coils forming large closed loops mounted on the upper surface of the platform 12 . For purposes of illustration the coils are shown to be rectangular in configuration, although other configurations are acceptable; the key factor is the area inside the coil and the number of loops of wire within each coil. As seen, one coil is disposed substantially in the plane of the platform 12 and the others are disposed in substantially vertical parallel planes spaced out along the length of the vehicle. Thus, one coil 40 is oriented substantially in the plane of the platform 12 and follows the peripheral edge of the platform. A second coil 42 is oriented in a substantially vertical plane perpendicular to the centerline of the vehicle and is located in the region of the housing 22 surrounding the lift engine 20 . A third coil 44 is oriented in a substantially vertical plane parallel to the plane of the coil 42 and is located substantially approximately in the middle of the vehicle 10 . Finally, a fourth coil 46 is oriented in a substantially vertical plane parallel to the planes of the coils 42 and 44 and is located just to the rear of the propellers 24 . The reason for this orientation is to permit the magnetic field to be focused sufficiently far ahead of the vehicle 10 to avoid detonating the mine under the vehicle or even sufficiently close thereto to cause damage to it. All of the coils are surrounded by an aluminum enclosure to prevent movement of the multiple loops of fine wire and to protect the loops of wire from environmental effects.
In a representative situation, the first coil encloses an area of approximately 85 m 2 , and consists of 14 turns of cable in seven groups connected in parallel. The other three coils 42 , 44 and 46 enclose an area of approximately 14.4 m 2 , and consist of 40 turns of cable in eight groups connected in parallel. The total weight of the magnetic coils is 6065 lbs. The coils are powered at 230 volts with the coil 40 requiring 16 Kwangtung and each of the vertical coils 42 , 44 and 46 requiring 14 Kwangtung for a total power requirement of 58 Kwangtung. Power for the coils is preferably provided by two electrical generators, belt-driven from the lift engine 20 . Suitable electronic controls are provided to generate time-phased signals to control the magnetic sweep pattern.
FIG. 4 illustrates the manner in which the present invention operates. The air cushion vehicle 10 is controlled remotely from the control vehicle 36 by the signals 34 picked up by the antenna 32 of the vehicle 10 . When the vehicle is in the desired location, the coils 40 – 46 are energized to emit a selected magnetic wave pattern, designated by the lines 48 , which extends sufficiently far in advance of the vehicle to detonate the submerged mine 50 while the vehicle 10 is still out of range of the explosive force of the mine. The general shape of the field pattern 48 is as shown in the drawings, but it is also mirrored above the surface of the water. The precise shape of the field pattern is difficult to describe and show since it varies with the time of duration of the time-phased signals and with the specific ship type that is being emulated.
The coil configuration described above provides an increased magnetic field intensity of 50% over the coil arrangement in the pontoon supported vessel described above, enabling larger ships to be simulated and a wider lane to be swept. The coils will be capable of generating a magnetic field with a minimum strength of 100 nT on the sea floor, covering a swath that is 150 meters wide in a range of water depths from 10 to 60 meters. The significance of these characteristics is that the vehicle of the present invention is capable of generating a magnetic field that is 50% wider and deeper than the pontoon supported craft described above, can emulate a larger ship and can provide a wider cleared channel.
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An underwater mine warfare countermeasure system is disclosed in which an air cushion vehicle carries a magnetic field generating system capable of generating a magnetic field pattern beneath the vehicle which extends sufficiently far from the vehicle in all directions to activate a magnetically responsive detonator in a mine while the vehicle is out of range of the explosive force of the mine. The magnetic field generating system generally is composed of a plurality of closed loop coils mounted on the deck of the vehicle, one coil being horizontal and in the plane of the deck, and another three being in vertical planes spaced along the length of the vehicle.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S. Ser. No. 08/903,023 filed on Jul. 30, 1997 in the name of Steven B. Bridgers and entitled “Smart Patch Connector” and claims priority under 35 USC 120 to provisional application Ser. No. 60/032,885 filed on Dec. 13, 1996 in the name of Steven B. Bridgers and entitled “Universal Buckminsterfullerene Inter/Intra Connector”.
FIELD OF THE INVENTION
[0002] The present invention relates to connector assemblies and, in particular, to an intemodal connector architecture modality for multinodal planar and surfacial configurations. Moreover, the invention relates to a universal, fully rotating dynamic connector for use in modeling, construction, and other fabrications.
BACKGROUND OF THE INVENTION
[0003] Many approaches have been taken for establishing multi-dimensional architecture for use as models, skeletal framework, building kits and the like. While creating versatile shapes, the resultant shapes are primarily static structures relegated to fixed configurations. Moreover, the internodal architecture was relatively rigidly defined, requiring numerous base connector designs for achieving varying shapes and contours.
[0004] For instance, U.S. Pat. No. 5,030,103 to Buist et al. a molecular model assembly having a plurality of articulating arms attached to a core member. Each arm is limited to articulation in a single plane, and subject to such constraints, could be connected to like adjacent components.
[0005] U.S. Pat. No. 3,333,349 to Brumlik discloses a molecular orbital model assembly wherein a plurality of preformed spoked coupling elements may be telescopically assembled with tube members for creating polyhedral shapes. Inasmuch as the coupling elements are rigid and preformed, each model requires a multiplicity of coupling elements. Once assembled a rigid, non-kinetic model is provided.
[0006] U.S. Pat. No. 4,778,184 to Fleischer discloses a multi-dimensional sculpture puzzle toy wherein a plurality of tubes are joined together with internal cords that serve as hinges and allow the device to form various geometric shapes. The cord is ineffective in transferring force or movement between the tubes.
[0007] U.S. Pat. No. 3,694,954 to Brumlik discloses a construction element having mating segments interconnected by a flexible strap. The arrangement allows limited relative movement between the segments but does not have the capability to transfer forces or movements between adjacent components.
[0008] U.S. Pat. No. 5,542,871 to Gabriel discloses a construction rod system wherein tie rods are releasably connected with joint elements. The tie rods have limited universal movement with respect to the joint elements for facilitating assembly. Once fixed in a three-dimensional array, a relatively rigid assembly is effected.
[0009] U.S. Pat. No. 4,484,430 to Rossman discloses a structural connector having a plurality of radially disposed arms independently rotatably connected to a common hub primarily for establishing planar support platforms.
[0010] U.S. Pat. No. 5,556,218 to Homer disclosed a wedge block clamping system for tubular member using a rigid multiple arm connector system.
[0011] U.S. Pat. No. 3,049,897 to Arpels discloses a three-link connector system accommodating relative angular movement between links about a common orbital point.
[0012] U.S. Pat. No. 4,020,566 to Dreiding discloses a construction set for stereochemical model using rigid arms releasably connected between hub members at releasable bayonet connections. The resulting structures are rigid.
[0013] U.S. Pat. No. 2,212,455 to Reed discloses an adjustable pipe railing fitting having a plural radial arm individually rotatably connected to a common hub. The resultant assembly is static and rigid.
[0014] U.S. Pat. No. 5,556,219 to Mason discloses a multiple prong connector hub that telescopically receives tubular connecting struts for creating rigid three-dimensional models.
[0015] U.S. Pat. No. 3,830,011 to Ochrymovich discloses a model having tubular struts interconnected by multiple pronged hub connector formed from a flexible sheet material. The resultant structures are rigid and fixed in configuration after assembly.
[0016] U.S. Pat. No. 4,288,947 to Huang discloses a modular dome structure formed of Y-joints and strut members that is rigidized by inflation after assembly through vulcanization and curing.
[0017] Individual assemblies using compression springs between a center body and radially extending arms have been proposed as effective as a single unit shock absorbing parachute deployable wind vane as disclosed in U.S. Pat. No. 4,080,925 to Moore. The indicator is not intended for coupling with other like structures.
[0018] Based on the foregoing, it is apparent that the prior art structures have limited ability for constructing structures using a common internodal architectural definition, requiring a plurality of adaptations to form variant structures. Further, the internodal structures are passive connecting systems accommodating limited relative movement and are primarily intended for static environments.
SUMMARY OF THE INVENTION
[0019] The present invention provides a universally compliant and restorative internodal connector architecture system wherein a plurality of nodal members are interconnected by a spring and strut assembly in a manner that permits manual or actuated relocation of the nodal spacial definition using standard modules. The system may include a nodal body member having an internal cavity and a plurality of compliant strut members. Each strut member includes a spring member having a passage therethrough operatively attached at one end to the nodal body member for universal compliant movement with respect thereto and communicating with said internal cavity. The spring members at the other end are operatively connected to an elongated hollow link member having an internal passage extending therethrough communicating with the passage in the nodal members. The link members are adapted for interconnection with a similar compliant strut member on another nodal body member with said passages and said cavity providing a continuous circuit therethrough for the deployment of operating systems therewithin.
[0020] The connector architecture is based on the dodecaicosohedral symmetry found in the carbon-60 molecule and many other naturally occurring structures. In such form, the connector is particularly suited for the construction of domes, spheres, tubes and other polyhedral structures. Therein the spring members function as flexible, tunable compliant connector modalities. Such compliancy permits the relative structural angles to vary enabling the structures in response to induced or directed movement to assume an equilibrium moved state through internal and/or external actuation. The connector architecture is compatible with conventional and micro-scale manufacture and assembly.
[0021] By incorporating the compliant elements, a plurality of accommodating and beneficial functions are attained. In conventional mechanics, torque, differential movement, relative rotation, and triaxial force transmission are provided. The elements may also be employed for electromagnetic and thermal control. Remote control systems may be used for effecting selective movement of the components. The extent and mobility of the resultant structures is a function of the resilience and attenuation of the connected members. The more resilient and finely tuned, the greater the range of movement. In geometrical array, the assembled structures based on the connector architecture may be folded and extended between stowed and deployed form.
DESCRIPTION OF THE DRAWINGS
[0022] The above and other features and advantages of the present invention will become apparent upon reading the following detailed description taken in conjunction with the accompanying drawings in which:
[0023] [0023]FIG. 1 is a connector module for an internodal connector architecture system in accordance with the invention;
[0024] [0024]FIG. 2 is a perspective view of a cube in accordance with an embodiment of the present invention;
[0025] [0025]FIG. 3 is a perspective view of a tetrahedron is accordance with another embodiment of the present invention;
[0026] [0026]FIG. 4 is a perspective view of internested connector assemblies in accordance with a further embodiment of the invention;
[0027] [0027]FIG. 5 is a side view of a connector module;
[0028] [0028]FIG. 6 is a front view of the connector module of FIG. 5;
[0029] [0029]FIG. 7 is a side view of the connector module taken along line 7 - 7 of FIG. 6;
[0030] [0030]FIG. 8 is an exploded front view of the connector module;
[0031] [0031]FIG. 9 is a front view of the components of the connector module; and
[0032] [0032]FIG. 10 is a perspective view of a further embodiment of internodal connector architecture system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Referring to the drawings for the purposes of illustrating preferred embodiments of the invention and not for limiting same, there is shown an internodal connector architectural system 10 for operatively and flexibly interconnecting a plurality of nodal sites disposed in three dimensional or planar orientation. For purposes of preliminary description, the invention will be referenced to the tetrahedral structure of FIG. 3 and the cubical structure of FIG. 2. However, it will become apparent that the system may be deployed in many configurations, regular or irregular, based on triangulated and non-triangulated spacial definitions. As to such definitions, the system accommodates and initiates selective, controlled and compliant response to externally or internally applied forces and movements to establish a desired reorientation. Controlled actuation and like utility subsystems may be incorporated or pendantly applied.
[0034] Referring to FIG. 1, an internodal connector architecture system 10 comprises base connector modules 12 in accordance with the invention to define spatially varying geometries. Each connector module 12 comprises a center node 20 having a plurality of universally compliant and restorative struts 22 connected at angularly spaced locations thereto. The struts 22 include a helically coiled spring 24 connected at an inner end to the node 20 and connected at an outer end to the inner end of an elongated link member 26 . The outer ends of the link member 26 are adapted to be connected with an adjacent strut or spring on another module for establishing in assembly with a plurality of like modules a three dimensionally configured frame assembly.
[0035] The node 20 , as shown additionally in FIGS. 7 through 9, is illustrated as spherical, however it will be apparent that various other configurations may be utilized for providing a common anchoring site for associated struts. Similarly, the spring 24 is illustrated as a helically coiled extension spring, however other universally compliant, coiled and uncoiled, triaxially translatable components may be utilized. As such, the spring 24 affords many compliant capabilities. The spring accommodates axial movement as shown by numeral 30 in FIG. 1. The spring dampens axial movement. The spring transmits torque. The spring dampens torque. The spring accommodates universal movement of the node relative to the strut. Upon displacement, the spring develops restorative forces for self-biasing to the original condition as shown by numeral 32 in FIG. 1. In the described embodiment, the spring 24 is a conventional helically coiled extension type operatively symmetrical with respect to a longitudinal axis. In assembly with the node 20 , the axes of the spring may be regularly angularly spaced and coincident. For the illustrated module, three modules are equally circumferentially spaced and lie in a common plane. Such a base configuration may be flexibly deployed as a standard module for establishing a wide variety of spacial definitions. However, a greater or lesser number of springs with varying polar orientations may be employed for discrete definitions, while retaining the benefits of the invention.
[0036] The springs may be connected between the nodes and the struts in any suitable manner allowing the spring to maintain the aforementioned functions. As illustrated in FIG. 8, the inner end of the spring 50 of the connector module 51 may be retained in a counterbore 53 in the node 52 . The outer end of the spring is connected with telescoping tubes 55 of a strut 54 . However, other mechanical, adhesive or otherwise connective means may also be employed for the connections.
[0037] The struts function as a spacing member between the respective nodes and springs. As illustrated, the struts are tubular and coaxially connected with the springs. However, the struts may provide for relative translation and articulation, actuated or accommodated, with non-coaxial alignment therebetween or with respect to the springs. As illustrated the struts are tubular having a longitudinal axis coaxial with the springs. Solid and non-cylindrical components may also be used as the connecting structure between the node sites.
[0038] In the illustrated cylindrical form or with interior passages defined in the components, various control, actuating and utility functions may be incorporated within the system for ancillary purposes or for effecting movement of the node sites. For instance, as shown in FIG. 10, a rotary or linear actuator 80 may be disposed within telescoping struts 82 , 84 and connected at operative ends with either the separate struts or with the nodes. Accordingly, the effective strut length may be extended or contracted to change the spacial definitions of the connected nodes and as accommodated by compliant movement of the other components. Such power supplies may be internally or exteriorly located and routed within the interior passages. Such movement may also be effected by actuators disposed exteriorly. Similarly rotary actuators will effect compliant resultant movement. The internal passages may also be utilized for passive routing such as electrical, hydraulic and other utility functions. Upon disabling of the actuators and the like, the restorative biasing of the compliant springs will return the system to the original equilibrium condition.
[0039] The foregoing features and advantages may be illustratively incorporated into the regular tetrahedron shown in FIG. 3. Therein, the nodal site is spherical, the springs of the helical extension type and equally angularly spaced in a common plane, and the struts of equal length and telescopically connected. It will be appreciated that such a configuration represents the greatest stressed condition for a polyhedral shape. Nonetheless, the structure is highly compliant in achieving the fully triangulated orientation. Other polyhedrons obviously impose lesser stressed conditions. Thus, it clearly demonstrates that a standard connector may be utilized in achieving a broad variety of spacial definitions. Nonetheless, dedicated nodes having orientations specific to the design structure may be used.
[0040] Each strut may also be manually shifted or actuated to vary the effective length to establish a revised nodal orientation and accordingly an irregular configuration. The compliancy of the structure readily accommodates such revision. Further, upon restoration of the original strut condition, the restorative biasing of the springs reestablishes the original condition.
[0041] Referring to FIG. 2, the illustrated cubical frame can also be established by the common components. As a non-triangulated architecture, the frame, in addition to the foregoing actuations, may also be collapsed and redeployed, demonstrating further the flexibility and adaptability of the system. Therein, the upper nodal plane may be moved, through the compliancy of the struts and springs into a common plane with the lower nodal plane. Upon release of the confinement, the restorative characteristic of the system will provide self-biasing to the original condition. The cubical frame may be further compliantly collapsed to align the struts in parallel juxtaposed positions whereby the frame is compacted along a longitudinal axis. Furthermore, the outer components may be inwardly folded for further compaction and storage. Upon release of confinement, the restorative biasing will reestablish the original cubical condition. Such capabilities allow complex configurations to be compactly stowed, transported, and redeployed at alternative sites.
[0042] The architecture may also be deployed in substantially planar array as shown in FIG. 10. Therein, a plurality of modules 80 are interconnected with a telescopic struts 82 and a rotary strut 84 as described above, with terminal peripheral components available for termination or connection with like or dissimilar structures. The resultant compliant conformal surface may adapt to varying abutting curvatures or be selectively actuated to achieve revised definition.
[0043] As shown in FIG. 4, plural geometric arrays may be inter-disposed. Thus, an outer body or hexagon 90 spatially defined by connector assemblies 92 may be compliantly connected with an inner body or hexagon 94 based on connector assemblies 96 by interconnecting compliant springs 98 . It will be appreciated that discrete, macro movement or deformation of the outer body 90 will limitedly affect the inner body 94 inasmuch as the reaction forces will be attenuated by the compliancy.
[0044] Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claims
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A universally compliant and restorative internodal connector architecture system wherein a plurality of nodal members are interconnected by a spring and strut assembly in a manner that permits manual or actuated relocation of the nodal spacial definition using standard modules.
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RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 13/963,036, filed on Aug. 9, 2013 which claims priority of U.S. Patent Application Ser. No. 61/681,888, entitled METHOD FOR THE TREATMENT OF ACNE, filed Aug. 10, 2012, the entire disclosure of each is hereby incorporated by reference as if being set forth in its entirety herein.
FIELD OF THE INVENTION
[0002] This application related to methods for the treatment of acne vulgaris, commonly referred to simply as “acne.”
BACKGROUND OF THE INVENTION
[0003] Acne is a commonly occurring skin disorder. It is characterized by an inflammation of the pilosebaceous unit, including the sebaceous gland. Acne lesions can take the form of comedones, papules, pustules, or nodules. Acne lesions typically appear on the face, but also occur on the back, chest and shoulders. Acne lesions are associated with Propionibacterium acnes ( P. acnes ). Growth of P. acnes is thought to be associated with, if not the cause of, the inflammatory component of acne.
[0004] The severity of acne varies widely from individual to individual, and also varies over time for any given individual. Even mild cases of acne can be cosmetically unappealing and at times disfiguring. Occasionally, acne lesions heal but leave permanent scars which are themselves sometimes prominent and permanently disfiguring.
[0005] There are a variety of treatments available for acne. Oral antibiotics (e.g. minocycline) may be used to reduce the population of P. acnes . Other oral antibiotics, such as doxycycline, have been used to treat acne when used at concentrations too low to have an antibiotic affect on P. acnes , but high enough to exert an anti-inflammatory action on the acne lesions. Topical retinoids, such as tretinoin, and topical antibiotics, such as clindamycin or azelaic acid, have also been used. In female patients, oral contraceptives have been observed to have an anti-acne effect, and are sometimes prescribed for that purpose. Orally administered isotretinoin is highly effective, but is known to produce a wide array of side effects, including sometimes severe psychiatric effects. Exposure to light, whether in the form of sunlight, or specific wavelengths of light, has also been shown to have a beneficial effect in the treatment of acne.
[0006] None of these treatments are compellingly effective, some have undesirable side effects, and all are subject to diminished effectiveness due to poor patient compliance—a common occurrence in the affected age group.
[0007] Photodynamic therapy (PDT) is an established therapeutic method for certain disorders. PDT is characterized by the use of (1) a phototherapeutic agent and (2) light. The phototherapeutic agent is applied or provided to the tissue or organ of interest. The light is used to cause a reaction (such as photoexcitation) in either the phototherapeutic agent, or in a metabolite of the phototherapeutic agent, or in a compound produced in response to the presence of the phototherapeutic agent (the activation reaction). This reaction results in a therapeutic effect.
[0008] Early phototherapeutic agents included porphyrins such as hematoporphyrin IX, hematoporphyrin derivative, or other such molecules, including Photofrin II.
[0009] The pioneering work of Kennedy & Pottier resulted in the discovery of the use of aminolevulinic acid (ALA) as a phototherapeutic agent. ALA is a precursor to a naturally occurring molecule—protoporphyrin IX. Exposing skin to light activates protoporphyrin IX in the skin. That is, the light excites or causes a reaction in the protoporphyrin IX molecule that results in the formation of reactive free radicals. Naturally occurring protoporphyrin IX can be activated by exposure to light, but occurs in quantities too small to cause any serious effect in normal tissue. By administering exogenous ALA, cells and tissues can be caused to produce greatly increased amounts of protoporphyrin IX. The resulting high concentrations of protoporphyrin IX can result in the generation of fatal quantifies of free radicals in the target cells/tissue when protoporphyrin IX is activated by exposure to light.
[0010] Kennedy & Pottier found that ALA-induced production of protoporphyrin IX made it possible to use PDT in the treatment of several disorders of metabolically active tissues. This technology has been used in the successful commercial product Levulan®, produced by Dusa Pharmaceuticals, and which has been approved by the U.S. FDA for the treatment of actinic keratoses.
[0011] Kennedy and his co-workers believed that ALA-based PDT could be used to treat acne, although they did not report any clinical resolution of acne by this method. See, U.S. Pat. No. 5,955,490. Also, they reported that the ability of light to excite protoporphyrin IX in acne lesions disappeared within 24 hours.
[0012] Kennedy reported that the ability of light to excite protoporphyrin IX in skin having acne lesions could persist to 24 hours if an occlusive covering was placed over the skin, but found that when this was done the surrounding healthy skin had as much free-radical generating protoporphyrin IX as did the acne lesions. As Kennedy contemporaneously reported, a phototherapeutic agent must have “a high degree of specificity” for the target tissue. Kennedy, J. C. “ Phtochemotherapy - Clinical Aspects ” NATO ASI Series, Springer-Verlag at p. 462 (1988). Kennedy's observation of the presence of equal amounts of protoporphyrin IX in acne lesions and in surrounding normal tissue is not specific at all.
[0013] Other workers in this field persisted in attempts to employ ALA-based PDT in the treatment of acne. See, U.S. Pat. No. 6,897,238 to Anderson. Anderson used ALA based PDT to treat acne in a small group of patients and taught that light must be applied to the skin within 1 to 12 hours after application of ALA to the skin containing acne lesions, preferably about three hours after application of the ALA.
[0014] Anderson's use of a 1 to 12 hour, and preferably a 3 hour waiting period between ALA application and exposure to light was consistent with what was by then the generally accepted timeline of ALA metabolism and protoporphyrin IX production. Research by Kennedy & Pottier showed that ALA was metabolized in mouse skin to result in peak protoporphyrin IX concentration in about six hours, with protoporphyrin levels returning to near pretreatment baseline in about 18 hours. Pottier et al, Photochemistry and Photobiology , Vol. 44, No. 5, pp. 679-87 (1986).
[0015] These anecdotal reports of the use of ALA-based PDT to treat acne were eventually followed by a full scale clinical trial on a group of patients large enough to provide statistically meaningful comparisons between the effectiveness of ALA-based PDT on one hand, and exposure to light alone on the other. The result of this clinical trial is available at www.clinicaltrials.gov, NCT 00706433. In this study ALA was applied to skin presenting acne lesions 45 minutes before exposure to activating light. This clinical trial determined that the use of ALA-based PDT produced results that were statistically indistinguishable from the use of light alone. That is, the ALA-based PDT had no effect.
[0016] An eight week study compared the effectiveness of ALA-based PDT with exposure to light alone as a treatment for acne. This study also compared delays of 15, 60 and 120 minutes between application of ALA and the exposure to photoactivating light. Among patients where the delay was either 15 or 120 minutes, there was no difference in the results obtained using ALA-based PDT or using light alone. For the 60 minute patients, light alone produced slightly better results than treatment with ALA-based PDT.
[0017] Thus, ALA-based PDT has not been an effective treatment for acne.
[0018] There exists a need to find a more effective way to utilize ALA-based PDT in the treatment of acne.
SUMMARY OF THE INVENTION
[0019] The inventors have discovered that in order for ALA-based PDT to be successfully used in the treatment of acne, the application of light after the application of ALA to the skin should be delayed by at least 12 hours, and possibly as long as 36 hours. An interval of 24 hours between application of ALA to the skin and exposure to light can result in optimal anti-acne therapy.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the method of this invention, ALA-based PDT is used to treat acne by applying an ALA compound to skin having acne lesions, and then waiting at least 12 hours before applying light to the skin to activate the resulting protoporphyrin IX. By that time, the ALA-induced protoporphyrin IX has not only persisted in the skin, but has localized in effective concentrations in the pilosebacious unit.
[0021] The data below shows that the ALA-based PDT method of this invention provides an effective treatment for acne. Contrary to the experience of the prior art in using various ALA-based PDT methods to treat acne, the method of this invention is effective, and, to a much greater degree, has the required specificity for acne lesions. This remarkably different and highly desirable result is obtained by departing from the conventional belief that ALA-induced protoporphyrin IX is largely dissipated within 12 hours.
[0022] The post-application waiting period before light exposure should be from about 12 to 48 hours, although waiting periods of 12 to 36 hours, 18 to 36 hours, 18 to 24 hours or 24 to 36 hours are preferred.
[0023] Derivatives of ALA, including alkylated derivatives of ALA, can also be used. These include C 1 to C 8 alkyl derivatives of ALA such as methyl ALA and hexyl ALA.
[0024] Topical formulations suitable for use in ALA-based PDT are well known in the art. These include ALA and its pharmaceutically acceptable salts, such as ALA hydrochloride and sodium ALA. Any topical vehicle that delivers ALA to the skin so that it can be taken up by the acne lesions can be used. Levulan® ALA is a formulation that is commercially available and suited to use in this invention.
[0025] The concentration of ALA in the topical formulation can range from 1 to 30 percent. Concentrations within this range can be selected on the basis of the volume of the formulation to be applied, the number of acne lesions, the general sensitivity of the patient's skin, and other clinical factors well known to practitioners, and well within the scope of good clinical judgment. Concentrations in the range of 5 to 20 percent are most useful, within 20 percent ALA being particularly useful.
[0026] The ALA can be applied to the skin by any of the conventional application techniques known in the art, such as swabs, brushes, cotton balls, gauze pads or the like. The Kerastick® application sold by DUSA Pharmaceuticals can also be used.
[0027] Light sources suitable for use in ALA-based PDT are also well known and generally available. The wavelengths of light that are capable of penetrating the skin and exciting the protoporphyrin IX molecule are well known to those skilled in the art. Devices capable of providing such light are also readily available, such as the BLU-U® illuminator. The BLU-U emits 417 nm blue light, a wavelength capable of activating protoporphyrin-IX, at a power density of 10 mW/cm 2 .
EXAMPLE 1
[0028] A 20 percent ALA Topical Solution (Levulan® Kerastick® (aminolevulinic acid HCl) was applied to a healthy female volunteer exhibiting mild to moderate acne vulgaris of the face. The subject's acne consisted primarily of inflammatory lesions (papules and pustules), however, non-inflammatory lesions (comedones) were also present in small numbers. Prior to application of the ALA solution, the subject's face was washed with soap and water and then dried. Two applications of ALA solution were applied to all exposed skin areas on the patient's face except for the immediate periorbital area. The ALA solution was allowed to dry for several minutes between applications. The subject was instructed to avoid exposure to sunlight or bright indoor light prior to returning for light activation and the subject was informed that sunscreens alone would not protect against exposure to light. The subject was undergoing no other treatment for acne at this time.
[0029] The subject returned approximately 30 hours after application of the ALA solution for light treatment using a BLU-U®, photodynamic therapy illuminator. Total light exposure time was 1000 seconds. The subject noted mild stinging and burning during the treatment, none of which was sufficient to cause interruption or cessation of the light exposure.
[0030] The subject was evaluated pre and post light exposure. Pre-light exposure examination noted that the inflammatory acne lesions appeared slightly more erythematous than at baseline (ALA solution application). Post-light treatment evaluation revealed increased erythema in the inflammatory acne lesions compared with pre-light treatment. Non-inflammatory lesions appeared to be similar to baseline both pre and post light exposure.
[0031] The subject was evaluated approximately 24 hours after light treatment. Punctate moderate erythema was noted in the inflammatory lesions with mild erythema and edema extending slightly into the perilesional skin. Erythema and edema in the inter-lesional skin areas was largely absent.
[0032] The subject was evaluated 3 weeks post light treatment. A significant reduction in the number and severity of acne lesions was noted. All but two of the inflammatory lesions present at baseline had resolved. The remaining lesions exhibited slight erythema in the lesion itself with no perilesional edema or erythema. The subject was satisfied with the reduction in acne provided by the treatment.
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This application is directed to a method of treating a patient with acne by applying a photodynamic agent to skin having acne lesions, waiting at least 12 hours, and then exposing the skin to which the photodynamic agent has been applied to light that causes an activation reaction.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to glycerol derivatives and a process for preparing the same. More particularly this invention relates to glycerol derivatives having the formula (I) as described herein which are useful as a central nervous system depressant, intermediates for the preparation of β-adrenergic blocking agents, as an inhibitor of platelet aggregation and as a choleretic agent.
2. Description of the Prior Art
It is well known that certain glycerol derivatives can be used as a metabolic intermediate of β-adrenergic blocking agents. For example, Drug Metabolism Review, Vol. I(1), 101-116 (1972) discloses 1-(2,3-dihydroxy)propoxynaphthalene as a metabolic intermediate. However, the pharmacological activities of these glycerol derivatives have not yet been studied in detail.
Compounds which are known as platelet aggregation inhibitors include nucleic acid (xanthine) derivatives, prostaglandines, 1,3-diphenadions (e.g., as disclosed in U.S. Pat. No. 2,672,483), but it is not known that glycerol derivatives exhibit an inhibitory activity on platelet aggregation.
SUMMARY OF THE INVENTION
An object of the present invention is to provide glycerol derivatives including the optically active isomers thereof which are useful as a central nervous system depressant, an intermediate for β-adrenergic blocking agents, a platelet aggregation inhibitor or a choleretic agent.
Another object of this invention is to provide a process for the preparation of the above-described glycerol derivatives.
A further object of this invention is to provide a pharmaceutical composition comprising at least one of the above-glycerol derivatives.
This invention accordingly provides a glycerol derivative of the general formula (I) ##STR2## including the optically active isomers thereof, wherein the ring A represents a substituted or unsubstituted 5- or 6-membered heterocyclic ring containing 1 or 2 oxygen atoms or nitrogen atoms or a substituted or unsubstituted 5- or 6-membered alicyclic ring, and a process for preparing the same.
DETAILED DESCRIPTION OF THE INVENTION
The glycerol derivatives according to the present invention of the general formula (I) have been found not only to be useful as the hereinbefore-described intermediates for the synthesis of β-adrenergic blocking agents but also to have, per se, an inhibitory activity on platelet aggregation.
The glycerol derivatives of the present invention are, therefore, of value as a new type of platelet aggregation inhibitors. In addition, it has been found that some of the glycerol derivatives of this invention have a choleretic activity.
Typical examples of the ring A in the formula (I) above can be represented by the following structures: ##STR3## wherein R represents a hydrogen atom, an alkyl group, an alkenyl group or an aralkyl group.
Particularly preferred examples of A are ##STR4## wherein R is as defined above, which form, together with the benzene ring, a carbostyril or 3,4-dihydrocarbostyril structure or an isocarbostyril or 3,4-dihydroisocarbostyril structure.
The term "alkyl group" as used herein designates a straight or branched chain alkyl group having 1 to 4 carbon atoms, e.g., a methyl, ethyl, isopropyl, butyl or the like group.
The term "alkenyl group" as used herein designates an alkenyl group having 2 to 4 carbon atoms, e.g., a vinyl, allyl, propenyl, butenyl or the like group.
The term "aralkyl group" as used herein designates a phenylalkyl group having 1 or 2 carbon atoms in the alkyl moiety, e.g., a benzyl or phenethyl group.
The glycerol derivatives represented by the formula (I) of this invention can be prepared by various processes.
The glycerol derivatives represented by the formula (I) ##STR5## wherein A is as defined above can be prepared by reacting the corresponding hydroxy compound represented by the formula (II) ##STR6## wherein A is as defined above, with a compound represented by the formula (III)
Y--CH.sub.2 OH (III)
wherein Y is a ##STR7## group or a ##STR8## group wherein X represents a halogen atom such as chlorine, bromine and iodine, in the presence of a basic compound as an acid acceptor.
The compound of the formula (II) which can be used in the above process includes:
i. 1-substituted or unsubstituted-5, 6, 7 or 8-hydroxycarbostyrils having the formula (IIa) ##STR9## wherein R is as defined above, and the 4-methyl substituted analogues of these compounds;
ii. 1-substituted or unsubstituted-5, 6, 7 or 8-hydroxy-3,4-dihydrocarbostyrils having the formula (IIb) ##STR10## wherein R is as defined above;
iii. 5, 6, 7 or 8-hydroxyisocarbostyrils having the formula (IIc); ##STR11##
iv. 5, 6, 7 or 8-hydroxy-3,4-dihydroisocarbostyrils having the formula (IId): ##STR12##
v. 5, 6, 7 or 8-hydroxyquinolines having the formula (IIe); ##STR13##
vi. 5, 6, 7 or 8-hydroxy-1,4-benzodioxanes having the formula (IIf); ##STR14## or
vii. 4, 5, 6, or 7-hydroxyhydroinden-1-ones having the formula (IIg). ##STR15##
These compounds as described above are well known in the art. For example, 5-hydroxy-3,4-dihydrocarbostyril is disclosed in Japanese Patent Publication No. 38789/71 and in Chemistry and Industry, 1435 (1970); 8-hydroxycarbostyril is disclosed in J. Org. Chem., 36, (23), 3490-3 (1971); 7-hydroxyindanone is disclosed in J. Chem. Soc., 1954, 4299 and 5-hydroxyisocarbostyril is disclosed in J. Am. Chem. Soc., 69, 1939 (1947).
The compounds represented by the formula (III) which can be used in the above reaction include glycerol β-halohydrins, wherein the halogen atom can be a chlorine, bromine or iodine atom, and glycidol.
The reaction between the compound (II) and the compound (III) can be carried out in the presence of a basic compound as an acid acceptor. Acid acceptors found to be useful in the reaction include any basic compounds, such as alkali metals, alkali metal hydroxides, alkali metal carbonates, alkali metal alkoxides organic bases and the like, but sodium metal, potassium metal, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium alcoholate, potassium alcoholate or piperidine, piperazine, pyridine, lower alkylamines, e.g., diethylamine, triethylamine, methylamine, etc. are preferably used. These basic compounds can be employed in a molar ratio of from about 0.5 to about 2 moles, preferably in an approximately equimolar proportion with respect to the compound (II).
Generally, the above described reaction can advantageously be carried out using approximately equimolar amounts of the compounds (II) and (III), but use of an excessive amount of either of these reactants does not adversely affect the reaction. It is usually preferable to use about 1 to 5 moles of the compound (III) per 1 mole of the compound (II).
This reaction can be carried out at atmospheric pressure (elevated pressures can also be used if desired) in the presence of an acid acceptor in the presence or absence of a solvent, for example, such as a lower alkanol, water, a lower alkyl acetate and a ketone. Suitable examples of lower alkanols are methanol, ethanol, isopropanol, n-propanol, n-butanol and the like. Suitable examples of lower alkyl acetates are ethyl acetate, methyl acetate propyl acetate and the like. Suitable examples of ketones are acetone and methyl ethyl ketone. When a solvent is used, the concentration of the reactants in these solvents can be preferably from about 10% to about 30% by weight. It is preferred to select the solvent depending upon the type of acid acceptor used. For example, in a preferred embodiment, lower alkanols are used with alkali metals and water is used with alkali metal hydroxides. When the acid acceptors used are organic bases as set forth above, the reaction can be carried out in the absence of a solvent or using a lower alkanol, a lower alkyl acetate and a ketone as a solvent.
The reaction temperature ranges from about 0° to about 150° C, preferably 50° to 100° C. The reaction time will vary depending upon the temperature and the type of the reactants employed, but usually ranges from about 1 to 10 hours. In a preferred embodiment, the reaction can be carried out for 2 to 5 hours at the reflux temperature of the solvent used.
The reaction product thus obtained can be isolated as crystals in a usual manner or further purified by, for example, recrystallization and the like. In a typical technique for isolation of the reaction product, the reaction mixture is filtered while warm to remove insoluble substances, and the filtrate is either cooled to precipitate crystals, which are then separated by filtration, decantation, etc. or the above filtrate is concentrated to dryness and the residue is either recrystallized from water, ethyl acetate or the above enumerated alcohols or extracted with chloroform and the like and the extract is dried and concentrated thereby isolating the product.
Alternatively, the compound of the formula (I) according to the present invention can also be prepared by reacting the hydroxy compound of the formula (II) with an epihalohydrin such as epichlorohydrin, epibromohydrin and the like in the presence of an appropriate acid acceptor to produce a compound having the formula (IVa) or (IVb) ##STR16## wherein R and X are as defined above, and hydrolyzing the resulting compound, particularly preferably under basic conditions.
The reaction between the hydroxy compound (II) and the epihalohyrin can be carried out in the presence of an acid acceptor in the presence or absence of a solvent. Suitable examples of acid acceptors and solvents which can be used are those enumerated above for the reaction between the hydroxy compound (II) and glycerol α-halohydrin or glycidol. The reaction temperature can range from about 0° to about 120° C, preferably from 50° C to 100° C. The reaction can be carried out by using the epihalohydrin in an amount of from about 1 to 5, preferably 3 to 4, moles per 1 mole of the hydroxy compound (II) and the reaction time generally ranges from about 2 to about 8 hours, more generally from 4 to 5 hours.
The subsequent hydrolysis of the compound represented by the formula (IVa) or (IVb) can be effected in the presence of a basic compound as set forth above at a temperature of about 0° to 150° C, preferably 60° to 100° C for a period of from about 1 to 10 hours. A solvent such as those enumerated above can be advantageously used in the hydrolysis.
Alternatively, the hydrolysis can be effected with an aqueous solution of an acid such as inorganic acids, for example, sulfuric acid, hydrochloric acid, phosphoric acid or perhalic acids, for example, perchloric acid having an acid concentration of from about 5% to about 20% by weight. The acid hydrolysis can be carried out at a temperature of from about 0° to about 100° C, preferably from 20° to 50° C for a period of from about 1 to about 8 hours, preferably from 3 to 6 hours.
The compounds represented by the formula (I) of the present invention can also be prepared by the following reaction scheme: ##STR17## wherein A and R are as defined above.
In the above reaction, a 5, 6, 7 or 8-hydroxy compound represented by the formula (II) is reacted with a glycerol derivative (V) in the presence of a basic compound to produce the acetone glycerol (VI) corresponding to the hydroxy compound (II), which is then hydrolyzed to obtain the desired product of the formula (I).
As is understood by those skilled in the art, the glycerol derivative (V) above contains one asymmetric center indicated by the asterisk * and is, therefore, optically active. Thus, in this reaction, depending on the optically active (R)-(-)-α-(p-toluenesulfonyl)-acetone glycerol (V) or (S)-(+)-α-(p-toluenesulfonyl)-acetone glycerol (V) isomer used, the corresponding (S)-(+)- or (R)-(-)-acetone glycerol, respectively, can be formed which is then hydrolyzed to prepare a glycerol derivative (I) as predominately an optically active R-(-)-glycerol (I) or (S)-(+)-glycerol (I) form. Such a process is quite advantageous where a particular optically active glycerol derivative (I) is desired over the other processes disclosed herein where a mixture of optically active glycerol derivative (I) is obtained.
The optically active glycerol derivatives (V) which can be used in the above reaction scheme can be prepared according to the methods described in E. Bear, J. Am. Chem. Soc., 67, 338 (1945), E. Bear, H. O. L. Fischer, J. Biol. Chem., 128, 463 (1939) and ibid, and J. Am. Chem. Soc., 70, 609 (1948).
The reaction between the 5, 6, 7 or 8-hydroxy compound (II) and the optically active glycerol derivative (V) can be carried out in the presence of a basic compound such as those enumerated for the reaction between the compound (II) and the compound (III), in a molar ratio of from about 1 to 3 moles of the optically active glycerol derivative (V) per mole of the 5, 6, 7 or 8-hydroxy compound (II), preferably using approximately equimolar amounts of the reactants, at a temperature of about 50° to 250° C, preferably 80° to 150° C. Solvents such as an alkanol having 1 to 4 carbon atoms e.g., methanol, ethanol, isopropanol, butanol and the like, 2-methoxyethanol, dioxane, dimethylformamide, acetonitrile and the like can be employed in the reaction.
The hydrolysis of the acetone glycerol of the general formula (VI) can be in an aqueous solution of a hydrolyzing agent such as acetic acid, trifluoro-acetic acid, hydrochloric acid, sulfuric acid, etc. at a temperature of about 0° C to 100° C for 10 minutes to 2 hours.
The present invention is further illustrated by the following Examples but these Examples are not to be construed as limiting the scope of this invention. Unless otherwise indicated, all parts, percentages, ratios and the like are by weight.
EXAMPLE 1
0.23 g of sodium metal was dissolved in 40 ml of methanol, and 2.53 g of 1-benzyl-5-hydroxy-3,4-dihydrocarbostyril and 1.3 g of glycerol α-monochlorohydrin were added to the resulting solution followed by refluxing the mixture for 6 hours. After allowing the mixture to cool, the precipitated crystals were filtered, and the filtrate was concentrated to dryness. The residue thus obtained was extracted with 50 ml of chloroform, and the extract was washed with a 5% aqueous sodium hydroxide solution and then water and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation and the resulting residue was recrystallized from ethanol to give 1.2 g of 1-benzyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 153° - 155° C.
EXAMPLE 2
2.0 g of potassium hydroxide was dissolved in 80 ml of methanol, and 4.8 g of 1-methyl-5-hydroxy-3,4-dihydrocarbostyril and 4.0 g of glycerol α-monochlorohydrin were added to the resulting solution followed by refluxing the mixture for 4 hours. After allowing the mixture to cool, the precipitated crystals were filtered, and the filtrate was concentrated to dryness. The residue thus obtained was extracted with 120 ml of chloroform, and the extract was washed with a 5% aqueous potassium hydroxide solution and then water and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation and the resulting residue was recrystallized from ethyl acetate to give 1.5 g of 1-methyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 120° - 121° C.
EXAMPLE 3
2.0 g of potassium hydroxide was dissolved in 80 ml of methanol, and 5.2 g of 1-ethyl-5-hydroxy-3,4-dihydrocarbostyril and 5.0 g of glycerol α-bromohydrin were added to the resulting solution followed by refluxing the mixture for 4 hours. The mixture was then worked up in the same manner as described in Example 1 to obtain a residue after removal of the chloroform by distillation. The residue thus obtained was recrystallized from ethyl acetate to give 1.9 g of 1-ethyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 105° - 107° C.
EXAMPLE 4
0.4 g of potassium hydroxide was dissolved in 40 ml of methanol, and 1.0 g of 1-allyl-5-hydroxy-3,4-dihydrocarbostyril and 1.5 g of glycerol α-monochlorohydrin were added to the resulting solution followed by refluxing the mixture for 6 hours. The mixture was then worked up in the same manner as described in Example 3 and recrystallized from ethyl acetate to give 0.6 g of 1-allyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 96° - 97.5° C.
EXAMPLE 5
0.23 g of sodium metal was dissolved in 40 ml of ethanol, and 1.63 g of 5-hydroxy-3,4-dihydrocarbostyril and 1.1 g of glycerol α-monochlorohydrin were added to the resulting solution followed by refluxing the mixture for 6 hours. After allowing the mixture to cool, the precipitated crystals were filtered, and the filtrate was concentrated to dryness. The residue thus obtained was extracted with 100 ml of chloroform, and the extract was washed with a 5% aqueous sodium hydroxide solution and then water and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation and the resulting residue was recrystallized from ethanol to give 0.7 g of 5-(2,3-dihyroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 173° - 175° C.
EXAMPLE 6
0.7 g of potassium hydroxide was dissolved in 30 ml of methanol, and 2.5 g of 1-benzyl-5-hydroxy-3,4-dihydrocarbostyril and 0.9 g of glycidol were added to the resulting solution followed by refluxing the mixture for 4 hours. After the mixture was concentrated to dryness, the residue was extracted with 50 ml of chloroform, and the extract was washed with a 5% aqueous potassium hydroxide and then water and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation and the resulting residue was recrystallized from ethyl acetate to give 1.4 g of 1-benzyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as colorless needle-like crystals having a melting point of 154° - 155° C.
EXAMPLE 7
0.8 g of potassium hydroxide was dissolved in 50 ml of methanol, and 1.63 g of 8-hydroxy-3,4-dihydrocarbostyril and 1.4 g of glycerol α-monochlorohydrin were added to the resulting solution followed by refluxing the mixture for 3 hours. The raction mixture was then concentrated to dryness, and the resulting residue was extracted with 50 ml of chloroform. The extract was washed with a 2% aqueous sodium hydroxide solution and then water, and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation and the resulting residue was recrystallized from ethanol to give 0.8 g of 8-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a light yellow amorphous solid having a melting point of 182° - 184° C.
EXAMPLE 8
In the same manner as described in Example 7, 6-hydroxy-3,4-dihydrocarbostyril was reacted with gylcerol α-monochlorohydrin to give 6-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 190° - 192° C.
EXAMPLE 9
In the same manner as described in Example 7, 7-hydroxy-3,4-dihydrocarbostyril was reacted with glycerol α-monochlorohydrin to give 7-(2,3-dihydroxy)propoxy-3,4-dihyrocarbostyril as white needle-like srystals having a melting point of 143° - 144° C.
EXAMPLE 10
1.0 g of sodium hydroxide was dissolved in 20 ml of water, and 1.0 g of 1-benzyl-5-(2,3-epoxy)propoxy-3,4-dihydrocarbostyril was added to the resulting solution followed by stirring the mixture at a temperature of 80° to 85° C for 6 hours. The reaction mixture was then filtered while hot to remove any insoluble materials, and the filtrate was cooled. The precipitated crystals were filtered and dried, and recrystallized from ethyl acetate to give 0.4 g of 1-benzyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as colorless needle-like crystals having a melting point of 154° - 155° C.
EXAMPLE 11
1.5 g of potassium hydroxide was dissolved in 30 ml of water, and 1.2 g of 1-methyl-5-(2,3-epoxy)propoxy-3,4-dihydrocarbostyril was added to the resulting solution followed by stirring the mixture at a temperature of 80° to 90° C for 8 hours. The reaction mixture was then filtered while hot to remove any insoluble materials, and the filtrate was cooled. The precipitated crystals were filtered and dried, and recrystallized from ethyl acetate to give 0.5 g of 1-methyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 120° - 121° C.
EXAMPLE 12
0.5 g of sodium hydroxide was dissolved in 10 ml of water, and 1.0 g of 5-(2,3-epoxy)propoxy-3,4-dihydrocarbostyril was added to the resulting solution followed by stirring the mixture at a temperature of 75° to 80° C for 3 hours. The reaction mixture was then concentrated to dryness, and the resulting residue was recrystallized from water to give 0.55 g of 5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 173° - 175° C.
EXAMPLE 13
0.5 g of sodium hydroxide was dissolved in 10 ml of water, and 1.1 g of 5-(3-chloro-2-hydroxy)propoxy-3,4-dihydrocarbostyril was added to the resulting solution followed by stirring the mixture at a temperature of 75° to 80° C for 5 hours. The reaction mixture was then concentrated to dryness, and the resulting residue was recrystallized from ethanol to give 0.42 g of 5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as a colorless amorphous solid having a melting point of 173° - 174° C.
Following the procedure described in Examples 10 to 13, the following compounds were prepared:
1-Ethyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 105° - 107° C after recrystallization from ethyl acetate,
1-Allyl-5-(2,3-dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 96° - 98° C after recrystallization from ethyl acetate,
8-(2,3-Dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 182° - 184° C after recrystallization from ethanol,
6-(2,3-Dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 190° - 192° C after recrystallization from ethanol, and
7-(2,3-Dihydroxy)propoxy-3,4-dihydrocarbostyril as white needle-like crystals having a melting point of 143° - 144° C after recrystallization from ethanol.
REFERENCE EXAMPLE 1
0.34 g of 5-hydroxy-3,4-dihydrocarbostyril and 0.15 g of sodium ethylate were added to 34 ml of 2-methoxyethanol, and the mixture was refluxed for 10 minutes. To the resulting mixture was then added a solution of 0.6 g of (R)-(-)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 6 ml of 2-methoxyethanol, and the mixture was refluxed for 3 hours. After allowing the mixture to stand overnight at room temperature (about 20° - 30° C), the solvent was distilled off under reduced pressure. The residue thus obtained was extracted with 100 ml of chloroform, and the extract was washed with 1N sodium hydroxide and then water and then dried over anhydrous sodium sulfate. The chloroform was then removed by distillation, and the residue was recrystallized from methanol to give 0.35 g of (S)-(+)-α-(3,4-dihydro-5-carbostyril)acetone glycerol as white crystals having a melting point of 171° - 173° C and [α] D 22 = +24.6° (c=0.8, CHCl 3 ).
REFERENCE EXAMPLE 2
0.68 g of 5-hydroxy-3,4-dihydrocarbostyril and 0.35 g of potassium ethylate were added to 7.0 ml of 2-methoxyethanol, and the mixture was refluxed for 10 minutes. To the resulting mixture was then added a solution of 1.2 g of (S)-(+)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 12 ml of 2-methoxyethanol, and the mixture was refluxed for 3 hours. The reaction mixture was then worked up in the same manner as described in Reference Example 1 to give 0.67 g of (R)-(-)-α-(3,4-dihydro-5-carbostyril)acetone glycerol as white crystals having a melting point of 171° - 172° C and [α] D 22 = -24.5° (c=0.8, CHCl 3 ).
EXAMPLE 14
9 ml of an 80% acetic acid aqueous solution was added to 0.9 g of (S)-(+)-α-(3,4-dihydro-5-carbostyril)acetone glycerol, and the mixture was heated at a bath temperature of 55° to 60° C for 30 minutes. After allowing the mixture to cool, 135 ml of diethyl ether was added to the mixture followed by cooling, and the precipitated crystals were filtered and recrystallized from ethanol to give 0.5 g of (R)-(-)-α-(3,4-dihydro-5-carbostyril)-glycerol as white crystals having a melting point of 191° - 192° C and [α] D 23 = -5.4° (c=0.4, pyridine).
EXAMPLE 15
5 ml of an 80% acetic acid aqueous solution was added to 0.5 g of (R)-(-)-α-(3,4-dihydro-5-carbostyril)acetone glycerol, and the mixture was heated at a bath temperature of 60° - 65° C for 30 minutes. After allowing the mixture to cool, 100 ml of diethyl ether was added to the mixture followed by cooling, and the precipitated crystals were filtered and recrystallized from ethanol to give 0.3 g of (S)-(+)-α-(3,4-dihydro-5-carbostyril)glycerol as white crystals having a melting point of 191° - 192° C and [α] D 23 = +5.4 (c=0.4, pyridine).
REFERENCE EXAMPLE 3
1.8 g of 6-hydroxy-3,4-dihydrocarbostyril and 0.7 g of sodium ethylate were added to 9 ml of 2-methoxyethanol, and the mixture was refluxed for 10 minutes. To the resulting mixture was then added a solution of 3.0 g of (R)-(-)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 6 ml of 2-methoxyethanol, and the mixture was refluxed for 3 hours. After allowing the mixture to cool, the solvent was distilled off under reduced pressure. The residue thus obtained was shaken with 100 ml of chloroform and 100 ml of a 1N sodium hydroxide aqueous solution, and the organic layer was separated, washed with 100 ml of a 1N sodium hydroxide aqueous solution and then 3 times with 100 ml of water and then dried over anhydrous sodium sulfate. The solvent was distilled off and the resulting residue was recrystallized from methanol to give 1.3 g of (S)-(+)-α-(3,4-dihydro-6-carbostyril)-acetone glycerol as white crystals having a melting point of 146° - 148° C and [α] D 21 = +5.3 (c=0.9, CHCl 3 ).
REFERENCE EXAMPLE 4
0.9 g of 6-hydroxy-3,4-dihydrocarbostyril and 0.35 g of sodium ethylate were added to 4.5 ml of 2-methoxyethanol, and the mixture was refluxed for 10 minutes. To the resulting mixture was then added a solution of 1.5 g of (S)-(+)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 7.5 ml of 2-methoxyethanol, and the mixture was refluxed for 3 hours. After allowing the mixture to cool, the solvent was distilled off under reduced pressure. The residue thus obtained was shaken with 50 ml of chloroform and 50 ml of a 1N sodium hydroxide aqueous solution, and the organic layer was separated, washed with 50 ml of a 1N sodium hydroxide aqueous solution and then 3 times with 50 ml of water and then dried over anhydrous sodium sulfate. The solvent was distilled off and the resulting residue was recrystallized from methanol to give 0.6 g of (R)-(-)-α-(3,4-dihydro-6-carbostyril)acetone glycerol as white crystals having a melting point of 145° - 146° C and [α] D 21 = -5.3° (c=0.9, CHCl 3 ).
REFERENCE EXAMPLE 5
1.8 g of 7-hydroxy-3,4-dihydrocarbostyril and 0.7 g of sodium ethylate dissolved in 9 ml of 2-methoxyethanol, and 3.0 g of (R)-(-)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 15 ml of 2-methoxyethanol were treated in the same manner as described in Reference Example 3. The solvent was distilled off to give a syrup which was then crystallized from diethyl ether. The crude crystals thus obtained were recrystallized from methanol to give 1.8 g of (S)-(+)-α-(3,4-dihydro-7-carbostyril)acetone glycerol as white crystals having a melting point of 114° - 115° C and [α] D 21 = +5.6° (c=1.1, CHCl 3 ).
REFERENCE EXAMPLE 6
0.9 g of 7-hydroxy-3,4-dihydrocarbostyril and 0.35 g of sodium ethylate dissolved in 4.5 ml of 2-methoxyethanol, and 1.5 g of (S)-(+)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 15 ml of 2-methoxyethanol were treated in the same manner as described in Reference Example 3, and the resulting residue was recrystallized from methanol to give 0.45 g of (R)-(-)-α-(3,4-dihydro-7-carbostyril)acetone glycerol as white crystals having a melting point of 114° - 116° C and [α] D 21 = -5.3° (c=0.7, CHCl 3 ).
REFERENCE EXAMPLE 7
2.4 g of 8-hydroxy-3,4-dihydrocarbostyril and 0.9 g of sodium ethylate dissolved in 12 ml of 2-methoxyethanol, and 4.0 g of (R)-(-)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 20 ml of 2-methoxyethanol were treated in the same manner as described in Reference Example 3. The solvent was distilled off to give a syrup which was then crystallized from diethyl ether. The crystals thus obtained were recrystallized from methanol to give 1.4 g of (S)-(+)-α-(3,4-dihydro-8-carbostyril)-acetone glycerol as white crystals having a melting point of 108° - 109° C and [α] D 21 = +5.5° (c=0.9, CHCl 3 ).
REFERENCE EXAMPLE 8
0.9 g of 8-hydroxy-3,4-dihydrocarbostyril and 0.35 g of sodium ethylate dissolved in 4.5 ml of 2-methoxyethanol, and 1.5 g of (S)-(+)-α-(p-toluenesulfonyl)acetone glycerol dissolved in 15 ml of 2-methoxyethanol were treated in the same manner as described in Reference Example 3, and the resulting residue was recrystallized from methanol to give 0.4 g of (R)-(-)-α-(3,4-dihydro-8-carbostyril)acetone glycerol as white crystals having a melting point of 109° - 110° C and [α] D 21 = +5.4° (c=0.8, CHCl 3 ).
EXAMPLE 16
4.5 ml of an 80% acetic acid aqueous solution was added to 900 mg of (S)-(+)-α-(3,4-dihydro-6-carbostyril)acetone glycerol prepared in Reference Example 3, and the mixture was heated at a bath temperature of 55° to 60° C for 30 minutes. After allowing the mixture to cool, 45 ml of diethyl ether was added to the mixture followed by cooling. The precipitated crystals were filtered, washed with diethyl ether and recrystallized from ethanol to give 400 mg of (R)-(-)-α-(3,4-dihydro-6-carbostyril)glycerol as white crystals having a melting point of 168° - 169° C and [α] D 21 = -7.9° (c=0.6, dimethyl sulfoxide).
EXAMPLE 17
500 mg of (R)-(-)-α-(3,4-dihydro-6-carbostyril)acetone glycerol prepared in Reference Example 4 and 2.5 ml of an 80% acetic acid aqueous solution were treated in the same manner as described in Example 16 to give 200 mg of (S)-(+)-α(3,4-dihydro-6-carbostyril)glycerol as white ccrystals having a melting point of 169° - 170° C and [α] D 21 = +8.2° (c=0.9, dimethyl sulfoxide).
EXAMPLE 18
600 mg of (S)-(+)-α-(3,4-dihydro-7-carbostryil)acetone glycerol prepared in Reference Example 5 and 3 ml of an 80% acetic acid aqueous solution were treated in the same manner as described in Example 16, and the resulting residue was recrystallized from a mixture of ethanol and diethyl ether to give 200 mg of (R)-(-)-α-(3,4-dihydro-7-carbostyril)glycerol as white crystals having a melting point of 126° - 127° C and [α] D 21 = -8.7° (c=0.6, ethanol).
EXAMPLE 19
400 mg of (R)-(-)-α-(3,4-dihydro-7-carbostyril)acetone glycerol prepared in Reference Example 6 and 2 ml of an 80% acetic acid aqueous solution were treated in the same manner as described in Example 16 to give 200 mg of (S)-(+)-α-(3,4-dihydro-7-carbostyril)glycerol as white crystals having a melting point of 125° - 126° C and [α] D 21 = +9.0° (c=0.5, ethanol).
EXAMPLE 20
7.0 g of (S)-(+)-α-(3,4-dihydro-8-carbostyril)acetone glycerol prepared in Reference Example 7 and 35 ml of 80% acetic acid were treated in the same manner as described in Example 16 to give 3.4 g of (R)-(-)-α-(3,4-dihydro-8-carbostyril)glycerol as white crystals having a melting point of 182° - 183° C and [α] D 21 = -39.7° (c=1.1, dimethyl sulfoxide).
EXAMPLE 21
500 mg of (R)-(-)-α-(3,4-dihydro-8-carbostyril)acetone glycerol prepared in Reference Example 8 and 2.5 ml of an 80% acetic acid aqueous solution were treated in the same manner as described in Example 16 to give 200 mg of (S)-(+)-α-(3,4-dihydro-8-carbostyril)glycerol as white crystals having a melting point of 182° - 184° C and [α] D 21 = +39.0° (c=1.2, dimethyl sulfoxide).
EXAMPLE 22
16 g of 5-hydroxyisocarbostyril was dissolved in 110 ml of a 1N aqueous sodium hydroxide solution, and 8 g of glycidol was added to the solution. The mixture was then refluxed for 2 hours while stirring. After allowing the mixture to cool, the precipitated crystals were filtered, and recrystallized from water to give 20 g of 5-(2,3-dihydroxy)propoxyisocarbostyril as colorless needle-like crystals having a melting point of 228° - 230° C.
EXAMPLE 23
To 100 ml of ethanol in which 2,5 g of sodium metal had been dissolved was added 15 g of 8-hydroxyquinoline. 12 g of epichlorohydrin was then added to the resulting solution and the mixture was refluxed for 8 hours while stirring. After completion of the reaction, the precipitated material was removed by filtration, and the mother liquor was concentrated to dryness. The resulting residue was recrystallized from ethanol-water to give 16 g of 8-(2,3-dihydroxy)propoxyquinoline as colorless needle-like crystals having a melting point of 193° - 194° C.
In the same manner as described in Example 22 and 23, the following compounds were prepared from the appropriate starting materials.
__________________________________________________________________________Procedure Recrystal- Melting(Example lization PointNo.) Starting Material Compound Solvent (° C) Appearance__________________________________________________________________________22 ##STR18## ##STR19## Ethanol 223 - 225 Colorless Plate-like22 ##STR20## ##STR21## Water 182 - 183 Colorless Needle-like22 ##STR22## ##STR23## Ethanol 119.5 Colorless Amorphous22 ##STR24## ##STR25## Ligroin 101 - 102.5 Colorless Needle-like23 ##STR26## ##STR27## Ethanol- Water 223 - 226 Colorless Amorphous23 ##STR28## ##STR29## Ethanol n-Hexane 160 - 163 Colorless Amorphous23 ##STR30## ##STR31## Ethanol 210 - 214 Colorless Amorphous__________________________________________________________________________
As described previously, the compounds of this invention possess an inhibitory activity on platelet aggregation. The inhibitory activity of some compounds of this invention and the method for determination of the activity are described hereinafter in greater detail.
The aggregation inhibitory activity was determined using an AG-II type aggregometer (made by Bryston Manufacturing Co.). A blood sample was withdrawn from rabbits as a mixture of sodium citrate and whole blood in a proportion of 1:9 by volume and centrifuged at 1000 rpm for 10 minutes to obtain a platelet rich plasma (PRP). The resulting PRP was separated, and the remaining blood sample was further centrifuged at 3000 rpm for 15 minutes to obtain a platelet poor plasma (PPP).
The number of platelets in the PRP was counted in accordance with the Brecher-Clonkite Method, and the PRP was diluted with the PPP to prepare a PRP sample containing platelets in an amount of 300,000/mm 3 for an adenosine diphosphate (ADP)-induced aggregation test and a PRP sample containing platelets in an amount of 450,000/mm 3 for a collagen-induced aggregation test.
0.01 ml of a solution of a test compound having a predetermined concentration (as shown in the Tables below) was then added to 0.6 ml of the PRP sample obtained above and the mixture was incubated at a temperature of 37° C for 1 minute. Then 0.07 ml of an ADP or collagen solution was added to the mixture. The mixture was then subjected to a transmittance determination and changes in the transmittance of the mixture were recorded using aggregometer at a stirrer rotation rate of 1100 rpm. In this test, Owren Veronal buffer (pH 7.35) was used for the preparation of solutions of ADP, collgen and the test compounds. ADP was adjusted to a concentration of 7.5 × 10 -5 M, and the collagen solution was prepared by triturating 100 mg of collagen with 5 ml of the above buffer and the supernatant obtained was used as a collagen inducer. Adenosine and acetylsalicylic acid were used as controls for the ADP-induced aggregation test and the collagen-induced aggregation test, respectively. The aggregation inhibitory activity was determined in terms of the percent inhibition (%) with respect to the aggregation ratio of controls. The aggregation ratio can be calculated by the following equation: ##EQU1## Wherein:
"a" is the optical density of the PRP,
"b" is the optical density of the PRP having incorporated therein a test compound and an aggregation inducer, and
"c" is the optical density of the PPP.
__________________________________________________________________________Inhibition of Collagen-Induced Aggregation In Rabbit Platelets(Inhibition %)__________________________________________________________________________ Concentration__________________________________________________________________________Compound 10.sup.-8 M 10.sup.-6 M 10.sup.-4 M__________________________________________________________________________ ##STR32## 8 11 100 ##STR33## 0 13 7 ##STR34## 0 0 0 ##STR35## 26 9 100 ##STR36## 4 18 13 ##STR37## 21 7 25
______________________________________Inhibition of ADP-Induced Aggregation InRabbit Platelets (Inhibition %) ConcentrationCompound 10.sup.-8 M 10.sup.-6 M 10.sup.-4 M______________________________________ ##STR38## 21 17 21 ##STR39## 0 13 7 ##STR40## 0 0 0 ##STR41## 26 9 100 ##STR42## 4 18 13 ##STR43## 21 7 25 ##STR44## 10 13 2 ##STR45## 0 6 2Adenosine 5 47 70______________________________________
______________________________________Inhibition of ADP-Induced Aggregation InRabbit Platelets (Inhibition %)______________________________________ ConcentrationCompound 10.sup.-8 M 10.sup.-6 M 10.sup.-5 M 10.sup.-4 M______________________________________ ##STR46## 0 8 16 49 ##STR47## 15 18 18 51Adenosine 15 63 74 92______________________________________
______________________________________Inhibition of Collagen-Induced AggregationIn Rabbit Platelets (Inhibition %)______________________________________ ConcentrationCompound 10.sup.-8 M 10.sup.-6 M 10.sup.-5 M 10.sup.-4 M______________________________________ ##STR48## 0 3 3 95 ##STR49## 3 7 17 95Acetylsalicylic Acid -- 8 12 100______________________________________
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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A glycerol derivative represented by the formula (I) ##STR1## wherein A is hereinafter defined, including the optically active isomers per se and mixtures of the optically active isomers, which are useful as a central nervous system depressant, an intermediate for the preparation of β-adrenergic blocking agents, an inhibitor of blood platelet aggregation or a choleretic agent, and a process for preparing the above glycerol derivative.
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[0001] The present invention claims priority to U.S. 61/105,153, which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a chuck, particularly a capping chuck for use in applying a cap to a bottle.
BACKGROUND OF THE INVENTION
[0003] Filling and capping processes typically include conveying bottles to a filling station and capping them at a capping station. The processes can also include various testing and control functions such as, for example, testing and control of fill volume, cap torque, conveyor velocity, etc.
[0004] The capping station comprises a capping mechanism. The capping mechanism can include torque sensors and convertors, various cap head designs, rotary screw heads, conveying apparatus, and various capping chucks for holding the caps. Capping chucks secure the caps to the bottles. Capping chucks can include a clutch that limits the torque applied to the cap. The clutch can include a magnetic engagement that may be adjusted for various torque requirements.
[0005] Various applications require frequent cleaning of the capping mechanism. In these applications, a reduction in surface area or mechanical junctions can facilitate cleaning and reduce downtime.
SUMMARY OF THE INVENTION
[0006] The present invention describes a capping chuck for a bottle capping machine. The capping chuck is capable of applying a pre-defined torque to a cap with reduced top load during application. The capping chuck includes a drive gear mechanically connected to a clutch which drives a jaw. The gripper head secures the cap to the bottle.
[0007] In one embodiment, the drive gear is mechanically connected to the clutch. A driveshaft connects the clutch to the jaw. A shield can protect the driveshaft. Preferably, the shield is perforated.
[0008] The gripper head includes a perimeter wall surrounding a base. The perimeter wall can be serrated to improve contact with the cap. The perimeter wall can also be tapered toward the base. Under load, the plunger can move in a direction parallel to the longitudinal axis of the driveshaft. The extent of movement can be controlled by a resistance element such as, for example, a spring.
[0009] The clutch is preferably separated from the gripper head by the driveshaft. The clutch can control the amount of torque at the jaw. The clutch can include friction or magnetic elements, and preferably can be adjusted. In an embodiment, the clutch includes at least two magnetic arrays that are disposed in opposite polarity. The magnetic array can include a plurality of magnetic elements. The mutual magnetic repulsion of the magnetic arrays controls the amount of torque at the jaw. When the torque exceeds the mutual magnetic repulsion, the clutch slips.
[0010] The drive gear can engage a bull gear on the capping mechanism. The bull gear is capable of driving a plurality of drive gears. The capping chuck can include an engagement device that ensures good contact of the drive gear with the bull gear. The engagement device can rotate the capping chuck relative to the bull gear to ensure positive engagement of the drive gear with the bull gear. The engagement device can include a slotted opening and an adjustment screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a first capping chuck of the prior art.
[0012] FIG. 2 shows the gripper head of FIG. 1 .
[0013] FIG. 3 shows the gripper head of FIG. 1 along a longitudinal axis.
[0014] FIG. 4 shows a second capping chuck of the prior art.
[0015] FIG. 5 shows the gripper head and the clutch of FIG. 4 .
[0016] FIG. 6 is an exploded view of the clutch of FIG. 4 .
[0017] FIG. 7 shows the capping chuck of FIG. 4 without the protective cover.
[0018] FIG. 8 shows an embodiment of the capping chuck of the present invention.
[0019] FIG. 9 shows a rear view of FIG. 8 .
[0020] FIG. 10 shows the gripper head of FIG. 8 along a longitudinal axis.
[0021] FIG. 11 shows the clutch and driving gear of FIG. 8 .
[0022] FIG. 12 shows a perspective view of the driving gear and an engagement device.
[0023] FIG. 13 shows the capping chuck of the present invention on a capping mechanism.
[0024] FIG. 14 shows a cross-section of an embodiment of a clutch of the present invention.
[0025] FIG. 15 is a cross-section of FIG. 14 through A-A.
DETAILED DESCRIPTION OF THE INVENTION
[0026] As shown in FIGS. 1-3 , a capping chuck 1 can include a driveshaft 2 that mechanically connects a drive gear 3 to a gripper head 4 . The drive gear 3 engages a bull gear (not shown) of a capping mechanism. In a multi-stage capping mechanism, the bull gear can drive a plurality of capping chucks. The bull gear rotates the drive gear 3 and the drive shaft 2 transfers the rotation to the gripper head 4 . In embodiments, the gripper head 4 is secured to the driveshaft 2 with a retention pin 5 . Removal of the retention pin 5 permits removal of the gripper head 4 from the driveshaft 2 .
[0027] The gripper head 4 can include a plunger 6 surrounded by a perimeter wall 7 . The perimeter wall 7 is discontinuous and consists of a plurality of gripper jaws 8 . The gripper jaws 8 typically consist of arc sections in combination forming a discontinuous perimeter. The plunger 6 and gripper jaws 8 are normally in an expanded position. Pressure on the plunger 6 causes the gripper jaws 8 to move inwardly. In practice, the capping chuck 1 is pressed down onto a cap (not shown), the gripper jaws 8 move inwardly thereby gripping the cap, and the driveshaft 2 rotates the gripper head 4 until the cap is secured to the bottle. An operator must carefully monitor the capping operation or excess torque can cause the gripper head 4 to strip the cap causing closure failure. Alternatively, excessive pressure can crush the bottle.
[0028] FIGS. 4-6 show another embodiment of a capping chuck. FIG. 7 shows a reverse view of the capping chuck. The capping chuck 41 includes a driveshaft 42 connecting a drive gear 43 to a gripper head 44 . The gripper head 44 includes a clutch 51 that can limit the torque transferred from the driveshaft 42 to the gripper head 44 . In this embodiment, the clutch 51 includes a first magnetic portion 61 separated by a spacer 62 from a second magnetic portion 63 . The strength of the magnetic portions 61 , 63 and the thickness and material of the spacer 62 control the torque limit. Typically, the spacer comprises a plastic such as, for example, unsubstituted and substituted polyolefins; although, any convenient substance can be used. While this embodiment can limit torque, it also has its problems. Liquid can infiltrate the clutch 51 and affect the torque transmitted to the gripper head 44 . For example, liquid can reduce friction so that the gripper head 44 does not impart sufficient force to the caps. Alternatively, dried residue can increase torque and strip the caps. Cleaning can be difficult because the clutch is part of the gripper head and is subject to splashing liquid. Cleaning involves disassembly of the clutch. Shields 45 have been used to reduce cleaning; however, shields can also complicate sanitation and cleaning. Rust can form in areas that are difficult to reach. Removing the rust can require removing the capping chuck from the capping mechanism.
[0029] FIGS. 8-12 show an embodiment of the present invention. A capping chuck 81 comprises a drive gear 82 mechanically connected to a clutch 83 . A driveshaft 84 connects the clutch 83 to a gripper head 85 . The driveshaft 84 also separates the clutch 83 from the gripper head 85 . Separating the clutch 83 and the gripper head 85 permits cleaning the gripper head 85 without disassembling the clutch 83 . In embodiments, the clutch 83 can be at least about 10 centimeters (about 3.937 inches) from the gripper head 85 .
[0030] The drive gear 82 and clutch 83 can be connected by an upper shaft 111 . The clutch can include any known mechanism including, for example, friction pads, magnetic elements, and combinations thereof. Conveniently, an adjustment bolt 110 can alter the torque that the clutch 83 transmits to the driveshaft 84 and gripper head 85 . The adjustment bolt 110 can operate, for example, to increase a spring tension or to separate elements of the clutch. For example, the adjustment bolt of a magnetic clutch can move apart the magnetic elements. The adjustment bolt 110 permits changing the applied torque without disassembling the clutch 83 .
[0031] In embodiments, a retaining pin 86 can secure the gripper head 85 to driveshaft 84 . A shield 87 can at least partially cover the driveshaft 84 . In operation, the shield can deflect liquid splatter from the driveshaft 84 and protect equipment operators from the driveshaft 84 . The shield 87 can be perforated. Perforation can facilitate cleaning.
[0032] The gripper head 85 includes a plunger 92 surrounded by a substantially continuous perimeter wall 91 . The perimeter wall 91 can extend to the gripper head opening. The perimeter wall 91 consists essentially of a single piece and is tapered to receive a cap (not shown). The taper diverges from the plunger 92 at an angle of at least about 1°, and preferably from about 2° to about 5°. The taper will have a first diameter at the gripper head 85 opening that is slightly larger than the cap and a second diameter at the plunger 92 that is slightly smaller than the diameter of the cap. Optionally, the second diameter can change with movement of the plunger 92 . The first diameter permits the gripper head 85 to receive the cap and the second diameter permits retention of the cap. In embodiments, the plunger 92 can undergo a displacement along the longitudinal axis 88 of the driveshaft 84 in response to a force. Movement of the plunger 92 inwardly from the gripper head 85 opening can decrease the second diameter. A resistance element (not shown) can control the plunger's ease of movement. The resistance element can be, for example, a spring or other elastic element. Advantageously, the taper reduces the compressive force required along the longitudinal axis 88 when compared to gripper heads having a jaw comprising arc sections.
[0033] The perimeter wall 91 and plunger 92 can preferably travel along the longitudinal axis 88 so that the gripper head 85 remains in contact with a cap as the cap is secured to a bottle. Conveniently, the length of travel can be at least about ¼ inch (about 0.635 centimeter). Prior art capping chucks require a longitudinal load to be placed on the gripper head to ensure contact with the cap. The load ensures the arc sections of the gripper jaws engage the cap during substantially the entire capping process. An excessive load could crush or otherwise distort small or thin-walled bottles, but insufficient load would not secure the cap to the bottle. The present invention requires little or no longitudinal load to engage the capping chuck to the cap. Sealing is improved and bottles can have thinner walls.
[0034] The capping chuck can include a clutch 83 as shown in FIGS. 14 and 15 . The clutch 83 includes at least two opposing mating surfaces 140 . Each mating surface 140 includes a magnetic array 141 a, 141 b. Each magnetic array 141 includes at least one magnet 142 . In embodiments, the mating surfaces 140 can define cavities 143 into which the magnets are recessed. The magnet 142 can be any suitable magnetic device including, for example, a permanent magnet, an electromagnet, or a combination thereof. In embodiments, the magnetic arrays 141 includes a plurality of magnets 142 disposed on the mating surface 140 . Magnetic clutches of the prior art separate the mating surfaces with a spacer. This is necessary because the magnets are arranged in opposite polarity, which draws the magnets on opposing mating surfaces towards one another. The spacer prevents the magnets from sticking together. Changing the thickness of the spacer will change the mutual attraction of the magnets, and so will change the torque at which the clutch will slip. The magnets must also be fixed into the cavities or they can pop out.
[0035] In the present invention, the magnetic arrays 141 are arranged so that the magnets 142 present the same magnetic pole towards the mating surface 140 . This ensures that the magnets 142 of a first magnetic array 141 a repel the magnets 142 on a second magnetic array 141 b. This repulsion causes the clutch 83 to operate so long as the torque on the clutch 83 does not exceed the repulsion force of the magnetic arrays 141 . Conveniently, the magnetic arrays 141 include a plurality of magnets 142 that are disposed so that the distance 144 between magnets 142 is at least equal to the radial arc 145 of the magnets 142 . The clutch 83 can work with only one magnet 142 on each mating surface 140 ; however, additional magnets 142 will produce a smoother mechanism. Advantageously, placing the magnets 142 in polar opposition pushes the magnets 142 into the cavities 143 so magnets 142 are less prone to popping out. Further, while a spacer can be used to separate the magnets 142 , it is not necessary as the mutual repulsion of the magnets 142 can create a suitable spacing 146 between the magnetic arrays 141 .
[0036] As shown in FIG. 13 , the capping chuck 81 can include a frame for securing the capping chuck 81 to a capping mechanism 130 . In embodiments, the capping mechanism 130 can operate a plurality of capping chucks 81 . With reference to FIG. 9 , the frame can include a pair of plates 96 a, 96 b united by spacer rods 97 . The driveshaft 84 extends through both plates 96 . The driveshaft 9 can pass through bushings (not shown) in each plate 96 to facilitate rotation of the driveshaft 84 .
[0037] A typical installation of the capping chuck 81 on the capping mechanism 130 includes a connector 131 such as, for example, a pair of lag bolts on the capping mechanism 130 that secures the capping chuck 81 to the capping mechanism 130 . The frame can define at least one slot 93 and opening 94 for receiving the lag bolts. The opening 94 will define a non-circular perimeter 100 so as to define at least one non-circular opening. The opening can be substantially oval. In embodiments, the plates 96 define a pair of slots 93 and openings 94 . The paired slots 93 and openings 94 resist movement away from the longitudinal axis 88 but do permit the capping chuck 81 to rotate about the longitudinal axis 88 . Such rotation can affect the engagement of the drive gear 82 with the bull gear so that if the gears do not align the capping chuck can be rotated to attain alignment. An adjustment screw 95 that extends into the opening 94 can lock the capping chuck 81 in proper engagement.
[0038] Numerous modifications and variations of the present invention are possible. It is, therefore, to be understood that within the scope of the following claims, the invention may be practiced otherwise than as specifically described. While this invention has been described with respect to certain preferred embodiments, different variations, modifications, and additions to the invention will become evident to persons of ordinary skill in the art. All such modifications, variations, and additions are intended to be encompassed within the scope of this patent, which is limited only by the claims appended hereto.
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A capping chuck for a bottle capping machine is capable of applying a pre-defined torque to a cap and reducing top load during application. The capping chuck includes a drive gear mechanically connected to a clutch. The clutch controls the torque transmitted to a gripper head through a driveshaft. The gripper head secures the cap to the bottle, and includes a substantially continuous perimeter wall surrounding a plunger that moves under load in a direction parallel to the longitudinal axis of the driveshaft. The extent of movement can be controlled by a resistance element such as, for example, a spring. An engagement device affects the contact the drive gear has with the bull gear of the capping mechanism. The engagement device can rotate the capping chuck relative to the bull gear to ensure positive engagement of the drive gear with the bull gear. The engagement device can include a slotted opening and an adjustment screw.
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BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention concerns static induction transistor and integrated circuit device utilizing same, and more particularly it pertains to improved normallyoperated static induction transistor and integrated circuit device utilizing same.
(b) Description of the Prior Art
The static induction transistor proposed by the present inventor may be characterized by its short channel structure and a high resistivity of the channel region. The high resistivity channel region enables one to form a gate-originating depletion region to pinch off the channel region by selecting the value of the gate bias voltage and also the gate-to-gate distance. This gate-to-channel depletion region, when pinching off the channel region, forms a potential barrier for charge carriers travelling between the source and the drain. The short channel structure remarkably reduces the series resistance from the source to the potential barrier, and makes the height of this potential barrier controllable also by the drain voltage, with the assistance of the high resistivity of the channel region. Thus, a static induction transistor realizes unsaturating drain I-V characteristics, as does the vacuum triode tube, in accordance with its operational principle which is to control the potential barrier height by the drain voltage as well as by the gate voltage. Forward biasing of a junction static induction transistor further adds a factor of minority carrier injection from the gate region.
The "pinch-off point" of a static induction transistor has a meaning similar to that of the conventional field effect transistor in the sense that the depletion region traverses the channel region and occupies a total cross section of the channel region at that position, but has a different meaning in the aspect that the pinch-off point in the static induction transistor has a controllable barrier height for those carriers flowing from the source to the drain, whereas the pinch-off point in the conventional field effect transistor has only the extremely narrowed neutral region, but it has no potential barrier. The above difference plus the difference in the magnitude of the series resistance from the source to the pinch-off point serve to produce a remarkable difference in the unsaturating drain I-V characteristics of the static induction transistor and the saturating drain I-V characteristics of the conventional field effect transistor.
A normally-off type static induction transistor is formed by selecting the impurity concentration in the channel region low and the channel width narrow to enable the depletion region due to the gate-to-channel built-in voltage to transverse the channel region and pinch off the current path. Forward bias operation is made possible in such normally-off type static induction transistor, and allows the static induction transistor to advantageously substitute for the bipolar transistor.
An IIL which has been developed as a bipolar logic circuit has the arrangement that the collector electrode of an injector transistor is formed in common with the base electrode of an inverter transistor, and that said inverter transistor is of the upside-down type, and also that the base electrode of this injector transistor is formed in common with the emitter electrode of the inverter transistor. Thus, an IIL has materialized high packing density, high-speed operation and so forth. An IIL type static induction transistor logic circuit which performs a circuit function similar to that of IIL has been proposed and developed also by the present inventor (Electronics Aug. 19, 1976, page 4E), and this circuit exhibits an ability superior to that of the bipolar type IIL. In such known structures, the inverter transistor empolyed has adopted an upside-down type structure, so that these known structures have the drawbacks such that the current injection efficiency and the carrier travelling efficiency from the emitter electrode to the collector electrode or from the source region to the drain region cannot be enhanced substantially. More particularly, in case an upside-down type static induction transistor (SIT) is employed, the drawbacks exist that the transconductance cannot be made large, and that accordingly the operation speed is limited.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved normal type static induction transistor which has a source region disposed in a surface portion, a gate region surrounding the source region and providing a pinch-off point near the source region and a drain region disposed also in a surface portion.
Another object of the present invention is to provide an IIL-type static induction transistor integrated circuit device which employs a normal type static induction transistor to serve as an inverter transistor, to enable operation of a higher speed.
A normal type SIT having the arrangement that its source region is provided in one main surface of a semiconductor wafer and that the area of its drain region is larger than that of the source region is difficult to be made into a multi-drain structure, and furthermore in case it is intended to locate the respective drain outputs at this upper surface of the chip for the purpose of wiring, the resulting structure will become almost impractical so long as a cconventional arrangement is employed. The present inventor has discovered that, in order to solve these problems, it is only necessary to adopt a structure such that an SIT is constructed in normal type structure, and that its drain is drawn out, to serve as a sub-drain, laterally through the chip, and also that the sub-drain is electrically drawn out as an upper-located drain via a high resistivity region having the same conductivity type.
Employment of a plurality of Schottky drains is effective to provide a plurality of independent outputs.
The present invention will be described in further detail with respect to some embodiments by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B and 1C are a diagrammatic top plan view, a diagrammatic sectional view and an equivalent circuit, respectively, of an embodiment for explaining the basic principles of the present invention.
FIGS. 2A, 2B and 2C and FIGS. 3A, 3B and 3C are diagrammatic top plan views, diagrammatic sectional views and equivalent circuits, respectively, of other embodiments of the present invention.
FIG. 4 is a diagrammatic top plan view of another embodiment of the present invention.
FIGS. 5 and 6 are diagrammatic sectional views of other embodiments of the present invention.
FIGS. 7A, 7B and 7C are a diagrammatic plan views, a diagrammatic sectional view taken along the line A--A' in FIG. 7A, and an equivalent circuit of another embodiment of the present invention.
FIG. 8 is an equivalent circuit diagram of another embodiment according to the present invention.
FIGS. 9 and 10 are diagrammatic sectional views of still other embodiments of the present invention.
FIGS. 11 and 12 are equivalent circuit diagrams of other embodiments of the present invention.
FIGS. 13A, 13B and 13C show a further embodiment of the present invention, in which:
FIG. 13A is a diagrammatic plan view; and
FIGS. 13B and 13C are diagrammatic sectional views taken along the lines XIIIB--XIIIB and XIIIC--XIIIC in FIG. 13A, respectively.
FIGS. 14A and 14B show a further embodiment of the present invention, in which:
FIG. 14A is a diagrammatic plan view; and
FIG. 14B is a diagrammatic sectional view taken along the line XIVB--XIVB' in FIG. 14A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1A and 1B which show the basic principles of the present invention, on the upper surface of a p-type semiconductor substrate 1 made of Si or GaAs, there is formed an n + type sub-drain embedded region 2, and on top thereof, there is formed an n - type epitaxial layer 3. It should be understood that, hereinafter the semiconductor body including this epitaxial layer will be called a semiconductor wafer. From the upper surface of said n - type epitaxial layer 3, there are formed a p + type emitter region 5 and a p + type collector region concurrently serving as a gate region 4 by relying on diffusion technique, ion implantation technique or like technique. Furthermore, an n + type base contact region 7, an n + type source region 6 and n + type drain regions 8 and 9 are formed by ion-implantation, diffusion or like techniques. On top of these respective regions which are formed in the epitaxial layer, there are formed an injector (emitter) electrode 5', a ground (base-source) electrode 6' and drain electrodes 8' and 9'. Also, on the entire bottom surface of the substrate 1, there is formed an electrode 1'. It should be noted, however, that the provision of this electrode on the bottom surface of the substrate 1 is not always necessary. Reference numeral 10 in these Figures represents an insulating film. In case the p-type semiconductor substrate is made of silicon, this insulating film may be formed of SiO 2 , Si 3 N 4 , Al 2 O 3 , AlN and like substances, or their mixture or their composite insulating film. In case, however, the substrate is made of GaAs, the insulating film is made of, for example, GaO x N y . Though not shown, the gate electrode to which is inputted an input signal is formed at an appropriate position on the gate region 4.
In these figures, two drains are shown. It should be understood, however, that the number of the drains may be increased or decreased depending on the requirement.
Also, it is possible to provide a split-gate structure which is proposed by the present inventor by dividing the p + type gate region 4 into two portions, one of which may be used as a floating gate or may be grounded. For example, in case the gate region is divided into two portions, and one of these two portions is grounded, the effective gate region subjected to potential variation becomes only one half, and accordingly the effective gate capacitance becomes half, and moreover the minority carriers which are injected into the channel region is efficiently pulled out by the grounded gate region to reduce the storage effect, so that a higher-speed operation is made feasible.
An equivalent circuit of the structure shown in FIGS. 1A and 1B is shown in FIG. 1C. An injector transistor Tr1 is constructed by p + type emitter region 5, n + type base contact region 7, n - type base region 3' and p + type collector region 4. Isolation region 20 is formed adjacent to the base contact region 7. An inverter transistor Tr2 is constructed by n + type source region 6, the p + type gate region 4, the n - type channel region 3", the n + type sub-drain region 2, the n - type region 3, and the n + type drain regions 8 and 9. The injector transistor supplies a load current. An input signal is applied to the gate electrode of the inverter transistor. More particularly, if the input signal is of a low level, the current from the injector transistor Tr1 is caused to flow into an input terminal, i.e. into the drain region of the preceding stage, so that the inverter transistor Tr2 is rendered "off" . In case, however, the input signal is of a high level, the current of the injector transistor Tr1 is injected into the gate region of the inverter transistor Tr2, so that the gate potential is elevated and the inverter transistor is rendered "on". These operations are similar to those of known IIL.
Since the inverter transistor Tr2 is of the normal type, it is easy to form an intrinsic gate point at a site sufficiently close to the source region. Thus, it is possible to set the series resistance from the source region to the intrinsic gate sufficiently low, and also to set the distance from said intrinsic gate to the drain region at a desired value, and furthermore the channel region may be made into a shape diverging toward the drain region. As a result of these considerations, it is possible to make the transconductance g m of the inverter transistor large, and to make the capacitance between the gate region and the source region small and also to make the capacitance between the gate region and the drain region small, and thus the frequency characteristic becomes very much improved, so that the operation speed is improved accordingly. At the same time therewith, the resistance at the conducting time is very small, and thus the driving ability can be intensified, and fan-outs can be taken in a large number.
In the structure shown in FIG. 1, the output drain electrode is formed by an n + type region. It should be understood, however, that the output drain electrode may be formed by Schottky electrode.
Also, vertically elongated output drain regions are provided in laterally adjacent rows in FIG. 1A. Acccording to such structure, however, there may arise such inconvenience that the amount of current will decrease in the drain region 9 which is located farther from the source region. For avoiding such inconvenience, it is only necessary to adopt some other arrangement in which the amount of current flow in the respective drains is equalized. For example, instead of disposing the n + type drain regions in vertically extending rows, they may be arranged in the form of parallel horizontal rows consisting of horizontal elongated drain regions in the plan view of FIG. 1A.
In FIG. 1B, in case there flows a punching-through current between the p + injector region 5 and the substrate 1, and in case, accordingly, there is inconveniently caused unnecessary dissipation of power, it is only necessary to provide a low resistivity region of an opposite conductivity type between this p + type region 5 and the substrate 1 to suppress the flow of punching-through type current, as will be explained later.
Also, in the embodiment shown in FIG. 1, gate regions 4 are shown to completely surround the source region and the channel region of the inverter transistor. It should be understood, however, that the arrangement of the gate regions do not necessarily follow this pattern. More particularly, it is also effective to make the gate structure into a split-gate structure by dividing the gate region 4 into two regions, one of which, i.e. the one which functions as a collector of a lateral bipolar transistor, is used as an active (driving) gate, and the other one may be used as a passive (non-driving or floating) gate or it may be coupled directly to the source region. In such split-gate structure, the static capacitance of the driving gate decreases, and it is possible to have the passive gate absorb those minority carriers injected from the active gate region into the channel region. Accordingly, the minority carriers are never stored for an extended period of time, so that the operating speed becomes extremely high.
The advantage of the IIL type logic circuit is found in that a wired logic can be taken by connecting the output drain region to a drain region of another inverter unit. In constructing such wired logic, it should be noted that, if a plurality of drain regions are provided on the sub-drain region as shown in FIG. 1, isolation between them will become imperfect, so that the desired wired logic will be difficult to obtain. Accordingly, if it is intended to construct a logic by wired coupling, it should be understood that, where the drain region is made of an n + type region, there will be the necessity that a one-input, one-output type inverter unit be constructed by incorporating such an insulating isolation region 20, as shown in FIGS. 2A and 2B.
In the embodiment of FIGS. 2A to 2C, an n + type sub-drain region is extended up to the entire peripheries within the entire isolation region 20 so as to prevent a punch-through type current from flowing between the p + type injector region 5 and the substrate 1. In this embodiment, the p + type regions 4 and 5 are formed apart from the sub-drain n + type region 2. They may be in contact with the sub-drain region 2. Further, a region for preventing the punch-through current may be provided separately from the sub-drain region 2. Other arrangements are similar to those of the embodiment shown in FIG. 1. The width and the impurity concentration of the n - type region 3 sandwiched between the p + type regions 4 and 5 are selected so that the n + type contact base region 7 and the n + type sub-drain region 2 will not become electrically conducting. This n - type region 3 sandwiched between the p + type regions 4 and 5 are in the state of punching-through, and a potential barrier is produced. In order to solve such problems in a simple way, it is only necessary to form the injector transistor as a MOS-FET. If it is intended to construct a logic circuit by a wired logic arrangement, and if it is intended to form an inverter unit so as to have a multiplicity of outputs, it is only necessary to take out the drain current by Schottky electrodes, instead of by the n + type regions and the electrodes. Such instance is shown in FIGS. 3A, 3B and 3C.
Drain electrodes 8' and 9' are constructed by Schottky electrodes, and an equivalent circuit will be as shown in FIG. 3C. Because of the formation of Schottky diodes, the output terminals V out1 and V out2 are isolated from each other. Where the semiconductor material is silicon, the injector voltage supply source V EE is set usually at a maximum value of about 1V or less than that. Where the semiconductor is made of GaAs, this value may be a little higher than that. Accordingly, if the forward voltage drop at the Schottky diode of the drain region is excessively great, the difference between logic levels, i.e. between the high level and the low level, becomes small, so that there will be less allowance for noise. When the semiconductor is made of silicon, it will be understood that by adopting a Schottky metal such as Pt, the forward voltage drop V f will become around 0.6 V, and thus the allowance for noise will become small, whereas if the Schottky metal is Ti, the V f can be around 0.27 V, so that the device can have a sufficient allowance for noise. Accordingly, it is desirable to employ, for the drain, such Schottky metal as Ti or other metal having a small value of V f . Further, it is known that the Schottky barrier height can be controlled by such means as adopting alloys, controlling the thickness and/or the properties of the interfacial layer, incorporating highly doped surface layers, and so on. The incorporation of a highly doped surface layer may be easily realized by using ion implantation and can change the effective height of a Schottky barrier over a quite large range. Where V f is about 0.3 V, the voltage of the inverter transistor Tr2 at the time of conduction will become about 0.4 V. By setting the potential at the cut-off time at about 0.6 V (V EE ≈0.7 V) or greater than that, there can be obtained a sufficient allowance for noise. If GaAs is employed as the semiconductor, the noise allowance will become further enhanced, so that the selection range of electrode materials will become broadened. Appropriate selection of the Schottky metal and the manufacturing process thereof will ensure stable operations. In order to make the noise allowance larger, it is desirable to arrange so that no unnecessary voltage drop is present between the drain electrode and the sub-drain region. To this end, the area of the Schottky electrode may be enlarged, or alternatively, in case the Schottky electrode cannot be made large, there may be provided an n + type region between the sub-drain region and the Schottky electrode by relying on, for example, ion-implantation technique. Or alternatively, there may be preliminarily formed recesses, for example, by removing part of the epitaxial layer, for the attachment of Schottky electrodes, and thereafter Schottky electrodes may be provided there. Since the external sides of the inverter unit are isolated by an insulating material such as SiO 2 , it should be noted that, for example the p + type gate region 4 may not be provided completely around the source region 6. In FIG. 3A, arrangement may be provided so that the n + type source region 6 vertically passes through the p + type region 4, so as to directly contact the isolation region 20. In FIG. 3A, the drain regions 8 and 9 shown in FIG. 1B are omitted, and Schottky drain electrodes 8' and 9' are in direct contact with an n - type epitaxial layer 3. By making the p + type gate region 4 into a split-gate structure by adopting such arrangement as discussed above, it is possible to reduce the area of the active gate region, so that the gate capacitance can be reduced accordingly. A plan view of such arrangement is shown in FIG. 4.
In FIG. 4, the gate region 4 is separated into an active gate region 4 and a floating gate region 14. This floating gate region 14 may, literally, have a floating potential, or alternatively it may be directly connected to the source region 6 by a conducting electrode via a certain amount of resistance. In case the floating gate region is electrically connected with the source region by some means, the storage effect of holes injected from the driving gate into the channel region is reduced and the operation speed is improved. For absorbing the minority carriers injected from the active gate region into the channel region as quickly as possible by the floating gate, the impurity concentration of the floating gate region may be increased, and this floating gate region may be connected directly to the source region. It should be understood here, however, that such arrangement may cause a current to easily flow between the driving gate region and the floating gate region, and hence that the current gain of the SIT may drop. If, however, the impurity concentration of the floating gate region is lowered, or if the floating gate region is connected to the source region of the SIT through a resistance such as one formed of polysilicon, a drop of current gain of the SIT can be prevented, though the speed with which minority carriers are absorbed out will become slightly prolonged. In case the impurity concentration of the p type floating gate region is low, the height of the potential barrier for holes will become slightly increased so that the absorption of holes will be limited to some extent. In case a resistance is inserted between the floating gate region and the source region of the SIT, it will be understood that, when a current flows into the floating gate region, the potential thereof will become increased, and thus the in-flow of holes above a certain level will become prevented. An instance wherein the n + type source region 6 is in direct contact with the insulation region 20 is shown in FIG. 4. It is, however, equally effective to separate the source region 6 and the insulation region 20 by the n - type region 3".
If the area of the sub-drain region in the structure of FIG. 1 is enlarged, this will bring about an increase in the capacitance between this sub-drain region and the substrate, serving as a cause for drop in the operating speed. In order to reduce such effect, it is only necessary to arrange, as shown in FIG. 5, that the substrate is made of a p + type semiconductor, and that a high resistivity region (which may be either one of n - type, p - type or i) 11 between the substrate p + type region and the embedded sub-drain n + type region 2, to ensure that this high resistivity region 11 will become depleted throughout the operation. It should be noted also that there is provided an n + type region 12 below the p + type region 5, in order to prevent a punching-through condition from taking place between the p + type region 5 and the p + type region 1 and to partially define the effective base region 3'. The incorporation of these regions 11 and 12 may be done in an appropriate manner depending on the desired design of such items as voltage of the voltage supply source, power dissipation and operating speed.
In other embodiments, it is also effective to provide a high resistivity layer between the n + type sub-drain region and the substrate.
A manner of provision of voltage supply sources has been shown in FIGS. 1C, 2C and 3C. More particularly, these Figures show that a positive voltage V EE is applied to the injector transistor 5, and both the substrate and the source region of the inverter transistor are grounded. Such arrangement, however, is not always necessary. Modification may be provided so that the source region is applied with a negative voltage, and that the injector electrode may be grounded.
FIGS. 1A through 5 show the instances wherein the injector transistor is made of a lateral bipolar transistor. In FIG. 6, however, there is shown an example in which the injector transistor employs an insulated-gate type field effect transistor. The insulating layer beneath the gate electrode 13 is made thin. In case a sufficient inversion layer is developed in the surface only by the contact potential of the gate electrode 13, this gate electrode 13 may be directly connected to the injector electrode 5'. On the other hand, in case there is not developed sufficient inversion layer only by the contact potential, the gate electrode 13 may be connected directly to the drain electrode 4'. In FIG. 6, p + type regions 5 and 4 serve as the source region and the drain region, respectively, of an injector insulated-gate type field effect transistor. Incorporation of those regions 11 and 12 and the incorporation of the split-gate structure of the gate region 4 as discussed in FIG. 5 may be carried out also in this embodiment as described above. It is needless to say that the injector transistor may be formed with an insulated-gate type transistor as shown in FIG. 6 in other arrangements shown in FIGS. 2 through 4.
In FIGS. 7A to 7C is shown another embodiment wherein the injector tansistor is made with an insulated-gate type transistor (which will hereinafter be called IG-FET). This is an example of one input and one output. FIG. 7A is a plan view. FIG. 7B is a sectional view taken along the line VIIB--VIIB' in FIG. 7A. FIG. 7C is an equivalent circuit. The gate electrode of this MOS-FET is directly connected to the source region of a normal type SIT. In this example, there is no fear at all that the gate region of the injector transistor will become electrically connected (short-circuited) with the sub-drain region of the inverter transistor. Since this is an instance of one output, the drain current is derived by an ohmic electrode 8'. Numeral 20 represents an isolation region such as SiO 2 between respective units. Another insulating region 21 is inserted for isolation between the gate region of the normal type SIT and the n + type region 8 assigned for deriving drain current. Along therewith, this region 21 has the effect of suppressing the minority carrier injection from the gate region of this SIT. Accordingly, unnecessary minority carrier injection is suppressed, so that the current gain of the SIT improves, and the storage effect of the minority carriers becomes reduced, and the operating speed is enhanced. V ss represents a voltage supply source. V in represents an input voltage, and V out represents an output voltage. It is also effective to arrange so that the channel region of the IG-FET has an impurity concentration different from that of other part of the epitaxial region 3, by relying on the ion-implantation or like technique. In case, however, the static capacitance between the sub-drain n + type region and the substrate and/or the conductance at the time of high-speed operation, for example, become problematical, it is only necessary to use a p + type substrate and to insert a high resistivity layer between the sub-drain region and this substrate.
When it is intended to provide a plurality of output terminals, it is only necessary to provide Schottky electrodes (diodes) having a low forward voltage drop directly on the n - type semiconductor region 3. An equivalent circuit of an instance of two outputs and using Schottky drain electrodes is shown in FIG. 8.
The operation of this example is similar to that of known such devices. In case the input V in is at a low level, the inverter SIT is in its cut-off state, so that the current of the injector IG-FET will be allowed to flow to the drain region of the inverter SIT of the preceding stage. When V in is changed to a high level, the inverter SIT will be reverted to a conducting state, so that the output voltage V out will be changed to a low level. The current of the injector IG-FET will flow into the gate region of the inverter SIT.
FIG. 9 shows an embodiment wherein a junction field effect transistor is employed as an injector transistor. A p + type region 5 serves as a source region. A p type region 14 serves as a channel region. An n + type region 15 serves as a gate region. An n - type region 3 forms a back-gate. A p + type region 4 serves as the gate region of the inverter transistor and concurrently serves as the drain region of the injector transistor. In FIG. 9, 5' and 15' represent a source electrode and a gate electrode, respectively. Other parts are similar to those of the preceding embodiments. Depending on the impurity concentration and the dimensions of the p type region 14, the gate electrode 15' may, in some instance, be directly connected to the electrode 5', or directly to the electrode 4'. The structure of this injector transistor can be applied in other embodiments.
FIG. 10 shows an embodiment wherein a field effect transistor having a floating gate is employed as an injector transistor, and the gate region of the inverter static induction transistor is arranged to reach a sub-drain region which is embedded in the wafer. An n + type region 16 is formed beneath a p type region 14 which serves as the channel region of the injector transistor, and this region 16 is used as a floating gate region. This n + type region 16 can be formed at the same time with the n + type region 2. A gate region and a gate electrode similar to those employed in the embodiment of FIG. 9 may be formed above the channel region 14. In the instant embodiment, the p + type region 4 reaches the embedded region 2, and the n - type region 3" which serves as the channel region is isolated from the n - type region 3. This arrangement improves the isolation of the inverter transistor, and along therewith it has the advantage that, when the gate region 4 is forwardly biased, those holes injected from the gate region into the surrounding n type region are directed effectively toward the n - type channel region 3".
Next, the structure and the impurity concentration according to the present invention will be briefly explained below. Let us now suppose that the distance between the gate regions of the inverter transistor which in the present invention is comprised of an SIT is designated as 2a (the width of the n - type region 3" located between the p + type gate regions 4), and that the impurity concentration of the n - type channel region 3" is designated as N D . In order to arrange so that the channel region becomes sufficiently pinched off only by the contact potential at the p + n - junction and that accordingly a high potential barrier may be developed within this channel region, if the semiconductor employed is silicon, the following formula will be followed:
N(2a).sup.2 <2.4×10.sup.15 cm.sup.-3.
It should be noted here that this 2a is scaled in μm unit. More specifically, if 2a×1 μm, it is preferable to set N at 2.4×10 15 cm -3 or less. In case 2a×2 μm, it is preferable to set N at 6×10 14 cm -3 or smaller. In very short channel structures, N.(2a) 2 requires to be made smaller as compared with the above-mentioned conditions, as the distance between the source region and the drain becomes smaller. This is important for realizing a prefectly "off" state of the transistor under the application of a certain drain voltage. In case the semiconductor is GaAs, the contact potential difference (built-in potential) at the p + n junction becomes large, so that the above-mentioned conditions will become deflected toward the large value side. The distance between the source region and the drain region is, for example, about 0.5 μm up to about 4 μm. In case the semiconductor employed is silicon, the n + type embedded sub-drain region is constructed by the diffusion or like technique of, for example, As, P, or Sb. However, in order to minimize the surface resistance, the employment of As is desirable. The p + type region may conveniently be formed by doping boron (B). The n + type region located at the surface may be formed either by the diffusion of As, P, Sb or like substance, or by ion-implantation of these substances. The impurity concentrations may be about 10 18 ˜10 21 cm -3 for both the n + type region and the p + type region. The impurity concentration of the p type substrate may be about 10 14 ˜10 16 cm -3 , and that of the p + type substrate may be about 10 17 ˜10 20 cm -3 . The impurity concentration of the n - type or p - type high resistivity region may be about 10 12 ˜10 15 cm -3 . The p + type region and the n + type region, in case of GaAs, are formed by Be, Zn, Cd or like substances or by S, Sn, Te, Si or like substances. In case of GaAs, the p type substrate 1 may conveniently be substituted by a substrate made of a material having a semi-insulating nature.
The current gain of the normal type SIT can be very great as compared with that of an upside-down type SIT. For example, a current gain of about several hundred can be easily provided. In the low current region where the carrier injection from the gate region is small, the value will easily reach several thousands. Accordingly, when the voltage of the gate region of the inverter SIT has elevated up to a predetermined high level, a constant injector current will cause an unnecessary current to flow into the gate region, so that unnecessary minority carriers will be injected into the channel region. In other words, the minority carrier storage effect will become prominent, so that the operation speed will drop. The injector transistor may be provided with a property of varying the level of current. However, in case the current of the injector transistor varies markedly, the frequency characteristic of the injector transistor will become associated with the operation speed, so that the operation speed will become lowered.
In order to eliminate the above-mentioned inconvenience, it is effective to connect a Schottky diode D gs between the gate region and the source region of the inverter SIT as shown in FIG. 11 and to arrange so that its forward voltage drop is in agreement with the predetermined high voltage level of the gate region. The injector current after the elevation of the gate voltage up to a predetermined level will then be allowed to flow through the Schottky diode D gs . The provision of said Schottky diode D gs may be carried out by constructing a Schottky diode locally in the source region of the SIT, and by directly connecting this diode to the gate region.
Similar effect can be materialized by the insertion of a Schottky diode D gd between the gate region and the drain region of an inverter SIT as shown in FIG. 12. After the gate has arrived at a predetermined potential, most of the injector current will pass through the Schottky diode D gd , and then flow between the drain region and the source region of the SIT. This Schottky diode D gd may be arranged so that a Schottky diode is constructed in the drain current deriving region of the SIT, and then this diode is directly connected to the gate region. According to this arrangement, the gate-drain voltage of the inverter SIT is substantially fixed at the forward voltage drop of the Schottky diode D gd and thus there will be never applied an unnecessarily deep bias between the gate region and the drain region. In the example of FIG. 12, the forward voltage drop of the Schottky diode D gd naturally requires to be greater than that of D 01 and D 02 .
In FIGS. 13A, 13B and 13C is shown another embodiment of IIL type structure. The inverter transistor has a structure similar to that of the preceding embodiment. However, the injector transistor is formed on top of the inverter transistor. In FIG. 13A, other electrodes than the Schottky drain electrode and insulating films are omitted and not shown. As the first step, an n-channel inverter transistor, like in the preceding embodiment, is formed within a semiconductor wafer. Thereafter, locally on top of a p + type gate region 4 and an n + type source region 6, there are formed an n type base region 19 and a p + type emitter region 5 by, for example, selective epitaxial growth technique. An emitter electrode 5' is formed on top of the emitter region 5 (see FIG. 13B). A source electrode 6' and a gate electrode 4' are formed on the exposed surfaces of the source region 6 and the gate region 4 of the inverter transistor, respectively (see FIG. 13C). The structure illustrated is schematic, and is locally exaggerated. It will be clear to those skilled in the art that various modifications and alterations may be possible. For example, the base region 19 may be formed wide so as to be in contact with the source region 6 with a large area, but an emitter region or an emitter electrode may be small only above the gate region 4. An equivalent circuit of this structure is similar to that shown in FIG. 3C, except that the fan-out is four in this embodiment. In this embodiment, an injector transistor is formed on an inverter transistor. Accordingly, the base region of this injector transistor is automatically connected to the source region of the inverter transistor, and thus it is extremely easy to electrically isolate the emitter region 5 of the injector transistor from the respective regions of the inverter transistor. Also, it is easy to enhance the injection efficiency of the injector transistor close to 1 (one) by, for example, adjusting the ratio of areas between the gate region which is contiguous with the base region 19 and the source region, or by forming an emitter region 5 only above the gate region 4.
FIGS. 14A and 14B show a further IIL type embodiment, in which an injector bipolar transistor is formed on an active gate region of an inverter static injection transistor.
In these Figures, an inverter static induction transistor is formed similar to the embodiment of FIG. 4. Namely, an n + type low resistivity sub-drain region 2 is formed in the surface portion of a p type substrate 1, and an n - type high resistivity epitaxial layer 3 is grown thereon. A p + type active gate region and a p + type passive gate region 14 are formed deeply in the n - type epitaxial layer 3 and a shallow n + type source region 6 is formed between these gate regions 4 and 14. A deep isolating region 20 is formed around the transistor structure described above and reaches the substrate 1 for isolating the sub-drain region 2 and also the n - type drain-like region 3 from the outside with the cooperation of the substrate 1 of the opposite conductivity type.
An n type base region 19 is formed on the active gate region 4 and the source region 6. This n type region 19 also covers part of the n - type channel region 3" and the passive gate region 14. A p + type emitter region 5 is formed on the n type base region 19 but only in the area located above the active gate region 4.
An injector (emitter) electrode 5' and a base/source electrode 19' are formed on the emitter region 5 and the base region 19, respectively. A pair of Schottky drain electrode 8' and 9' are formed on the n - type region 3.
The impurity concentration and the dimensions of the channel region 3" defined by the gate regions 4 and 14 are so selected so as to insure that the depletion layers growing from the pn junctions between the n - type channel region 3" and the p + type gate regions 4 and 14 can pinch off the channel region 3", but nevertheless the potential barrier formed by these depletion layer never becomes unsensitive to the drain voltage with respect especially to the barrier height, and also to its length. Namely, when the sub-drain region 2 is at a higher forward voltage, the height of the potential barrier formed by those depletion layers lessens to realize barrier height control by the drain voltage. The base region 19 has a thin thickness so that the emitter injection efficiency is rendered high, and the resistance between the base electrode 19' and the source region 6 is rendered very small. An electrode 4' shown in FIG. 14A is a gate electrode to be used for external connection. In this embodiment, the substantial portion of the injector bipolar transistor is formed only on the active gate region of the split gate configuration. Therefore, the emitter injection efficiency is very high and the gate capacitance is low to achieve low power, high speed operation. Furhtermore, the source electrode of the inverter transistor is formed on the base region to control the source potential through the base region. This arrangement, however, gives little effect to the porformance of the inverter transistor itself and contributes to making the manufacture of the device somewhat easier. Out-diffusion or auto-doping from the p + type gate regions 4 and 14 and from the n + type source region 6 may be effectively utilized in the formation of the n type layer 19. Namely, the resistivity of the n type layer 19 may be increased in those areas disposed on the p + type regions by out-diffusion of the opposite conductivity type impurities, and the resistivity may be reduced in that area disposed on the n + type region by out-diffusion of impurities of similar conductivity type. Thus, the source resistance of the inverter transistor and the capacitance between the source electrode 19' and the active gate region 4 can be kept very low.
An integrated circuit which employs a normal-type SIT of the present invention serving as an inverter transistor and having its source region formed in the surface of the semiconductor body, and having a sub-drain region formed as an embedded region, needless to say, is not limited to those structures shown in FIGS. 1 through 12. Any structure may be employed provided that the inverter transistor is formed by a normal-type SIT and also that a desired number of drain electrodes are provided on the surface above the embedded sub-drain region. The number of the drain electrode is not limited to single, but it may be two or three or more if Schottky electrodes are employed. Furthermore, a structure having respective regions of reversed conductivity types may be used if the polarities of the voltages of the voltage supply sources are reversed. Also, in the drawings, there have been shown only those inverter units of either one-input, one-output or a multiplicity of outputs. It should be understood, however, that the provision of a plurality of such inverters will enable one to construct any desired logic gate invariably as wired logic.
The integrated circuit employing the normal-type SIT of the present invention can be easily manufactured by relying on known crystal growth technique, diffusion technique, ion-implantation technique and fine processing technique.
The integrated circuit employing, as an inverter transistor, the normal-type SIT of the present invention is able to display the high-speed operation inherent to a normal-type SIT, so that a high packing density and a high-speed operation with a very small power dissipation can be materialized.
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A static induction type semiconductor device containing a normal type static induction transistor having the structure that a source region, gate regions and drain regions are arrayed in a main surface of a channel-constituting semiconductor region, and that a sub-drain region is formed in the opposite surface of the channel-constituting semiconductor region so as to extend from a position corresponding to the source region up to a position corresponding to the drain regions. The provision of this sub-drain region makes it possible to realize easy isolation of a normal vertical structure static induction transistor in a semiconductor wafer, the normal vertical structure contributing to increasing the transconductance, and to improving the speed of operation, without sacrificing a high packing density.
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