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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an inhaler assist device which supports different types of anti-static chambers.
2. Description of the Related Art
Because metered dose inhalers are often difficult to operate various devices for employing leverage to enhance the actuation of the metered dose inhalers have been developed. Often anti-static chambers must be used with metered dose inhalers making it cumbersome and even more difficult for operators to handle. The prior art devices have shortcomings which the present invention attempts to address through the development of the inhaler assist device useable with an anti-static chamber. In particular, the present invention addresses holding the anti-static chamber while aiding in actuation of a metered dose inhaler.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an inhaler assist device shaped and dimensioned for supporting a metered dose inhaler and an associated anti-static chamber in a manner allowing for assisted compression of the metered dose inhaler to dispense a dosage therefrom. The inhaler assist device includes an L-shaped housing assembly pivotally connected to a lever actuator. The housing assembly includes a first housing leg and a second housing leg. The first housing leg includes a first end and a second end and the second housing leg includes a first end and a second end. The respective second ends of the first housing leg and the second housing leg are fixedly connected, and a first end of the lever actuator is pivotally secured to the first end of the first housing leg defining a hinge therebetween. The housing assembly includes a planar base wall and lateral side walls extending from base wall, wherein the base wall and the lateral side walls create a cavity shaped and dimensioned for receipt of the metered dose inhaler and an anti-static chamber clip. The lever actuator includes a planar base wall and lateral side walls extending from the base wall.
It is also an object of the present invention to provide an inhaler assist device wherein the lever actuator also includes a plurality of support cross members extending downwardly from the base wall and between the lateral side walls.
It is another object of the present invention to provide an inhaler assist device wherein the lever actuator includes first, second, and third support cross members extending downwardly from the base wall and between the lateral side walls.
It is a further object of the present invention to provide an inhaler assist device wherein the first cross member is formed at the first end of the lever actuator, the second cross member is formed for engagement with the metered dose inhaler, and the third cross member is formed on a side of the second cross member opposite the first cross member.
It is also an object of the present invention to provide an inhaler assist device wherein the third cross member extends inwardly further than the first cross member or the second cross member.
It is another object of the present invention to provide an inhaler assist device including a concave recess shaped and dimensioned for positioning of the metered dose inhaler, the concave recess being defined by the first cross member and the third cross member of the lever actuator, the base wall of the lever actuator between the first cross member and the third cross member, and the lateral side walls of the lever actuator between the first cross member and the third cross member.
It is a further object of the present invention to provide an inhaler assist device wherein the concave recess is further defined by the base wall and lateral side walls of the first housing leg adjacent the first end of the first housing leg.
It is another object of the present invention to provide an inhaler assist device wherein the anti-static chamber clip is composed of first, second, third and fourth connection points shaped and dimensioned for frictionally engaging the anti-static chamber.
It is a further object of the present invention to provide an inhaler assist device wherein the first and second connection points are upper edges of the lateral side walls as they extend along the second housing leg.
It is also an object of the present invention to provide an inhaler assist device wherein the third and fourth connection points are formed along the lateral side walls extending along the first housing leg and are inwardly extending members defining substantially linear contact surfaces substantially parallel to and facing the first and second connection points.
It is another object of the present invention to provide an inhaler assist device wherein the spacing between the first, second, third and fourth connection points is such that a first end of the anti-static chamber may be positioned therein with the first, second, third and fourth connection points are shaped and dimensioned for frictionally engaging the anti-static chamber.
Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the present invention with an anti-static chamber attached.
FIG. 2 is a cross sectional view taken along line 2 - 2 of FIG. 3 .
FIG. 3 is a front view of the present invention with an anti-static chamber attached.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The detailed embodiment of the present invention is disclosed herein. It should be understood, however, that the disclosed embodiment is merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art how to make and/or use the invention.
In accordance with the present invention, and with reference to FIGS. 1 to 3 ,
an inhaler assist device 10 is disclosed. The inhaler assist device 10 includes a housing assembly 16 pivotally connected to a lever actuator 18 . The housing assembly 16 provides support for a metered dose inhaler 12 and anti-static chamber 14 as will be discussed below in greater detail. The lever actuator 18 includes a pivot first end 20 and a free second end 22 .
The housing assembly 16 is substantially L-shaped and includes a first housing leg 24 and a second housing leg 26 . The first housing leg 24 includes a first end 30 and a second end 32 . The second housing leg 26 includes a first end 34 and a second end 36 which is common with second end 32 of first housing leg 24 . The respective second ends 32 , 36 of the first housing leg 24 and the second housing leg 26 are fixedly connected, and the pivot first end 20 of the lever actuator 18 is pivotally secured to the first end 30 of the first housing leg 24 by a pivot pin 21 to form a hinge 23 .
The hinge 23 pivotally connects the first housing leg 24 with the lever actuator 18 . A concave recess 38 is formed at the meeting point of the first housing leg 24 and the lever actuator 18 . As will be discussed below in greater detail, the concave recess 38 is shaped and dimensioned for receiving the base or second end 60 of the metered dose inhaler 12 in a friction fit relationship. The concave recess 38 may be thought of as the combination and mating of the first end 30 of the first housing leg 24 and the first end 20 of the lever actuator 18 .
More particularly, the housing assembly 16 , in particular, the first housing leg 24 and the second housing leg 26 , includes a base wall 54 with an inwardly facing surface 56 and an externally facing surface 58 . The housing assembly 16 also includes lateral side walls 70 extending inwardly from base wall 54 . As will be appreciated based upon the following disclosure, the combination of the base wall 54 and the lateral side walls 70 creates a cavity shaped and dimensioned for receipt of the metered dose inhaler 12 in the first housing leg 24 . The lateral side walls 70 include a slot 120 which functions to allow the lateral side walls 70 to flex outward when an anti-static chamber 14 is press fit into the inhaler assist device 10 .
Similarly, the lever actuator 18 includes a base wall 44 with an inwardly facing surface 46 and an externally facing top surface 48 . The lever actuator 18 also includes lateral side walls 72 extending from base wall 44 . As will be appreciated based upon the following disclosure, the combination of the base wall 44 and the lateral side walls 72 defines a generally U-shaped cavity. The lever actuator 18 also includes support cross members 74 , 76 , 78 extending downwardly from the base wall 44 and between the lateral side walls 72 . The first cross member 74 is formed at the tip of the first end 20 of the lever actuator 18 . A second cross member 76 is formed for engagement with the second end 60 of the metered dose inhaler 12 and a third cross member 78 is formed on the side of the second cross member 76 opposite the first cross member 74 . The third cross member 78 extends inwardly further than the first or second cross members 74 , 76 and functions to retain the second end 60 of the metered dose inhaler 12 in position within the lever actuator 18 by preventing lateral movement of the second end 60 of the metered dose inhaler 12 toward the free second end 22 of the lever actuator 18 .
With the foregoing in mind, the concave recess 38 in which the second end 60 of the metered dose inhaler 12 is positioned is defined by the first and third cross members 74 , 78 of the lever actuator 18 , the base wall 44 of the lever actuator 18 between the first and third cross members 74 , 78 , and the lateral side walls 72 of the lever actuator 18 between the first and third cross members 74 , 78 . In addition, the concave recess 38 is further defined by the base wall 54 and lateral side walls 70 of the first housing leg 24 adjacent the first end 30 thereof.
The metered dose inhaler 12 is positioned, and frictionally fit, within the cavity defined by the base wall 54 and the lateral side walls 70 of the housing assembly 16 along the first housing leg 24 , and extends between the concave recess 38 and the second housing leg 26 such that the application of pressure forcing the lever actuator 18 toward the second housing leg 26 will cause compression of the metered dose inhaler 12 to thereby dispense a dosage therefrom. Proper positioning of the metered dose inhaler 12 between the concave recess 38 and the housing assembly 16 is achieved by the provision of a shelf 80 at the junction of the first housing leg 24 and the second housing leg 26 . The shelf 80 includes an upper support surface 82 shaped and dimensioned for engaging the dispensing, or first, end 62 of the metered dose inhaler 12 .
In addition to housing the metered dose inhaler 12 , the housing assembly 16 is particularly shaped and dimensioned to engage and retain an anti-static chamber 14 required to be used with a metered dose inhaler 12 by many users, with the metered dose inhaler 12 secured thereto. Anti-static chambers come in different shapes and sizes as such the inhaler assist device 10 is design to hold at least two different brands of anti-static chambers. As shown in the figures, and as those skilled in the art will certainly appreciate, the anti-static chamber 14 is frictionally secured to the dispensing end 62 of the metered dose inhaler 12 . The anti-static chamber 14 is secured thereto at a transverse orientation relative to the longitudinal axis of the metered dose inhaler 12 .
Attachment of the anti-static chamber 14 , and ultimately the metered dose inhaler 12 , to the housing assembly 16 is achieved by providing the housing assembly 16 with an anti-static chamber clip 50 . The anti-static chamber clip 50 includes a clip recess 100 . The anti-static chamber clip 50 is generally composed of four connection points comprised of 51 a , 53 a , and 51 b , 53 b (opposite 51 a and 53 a , respectively) shaped and dimensioned for frictionally engaging the coupled end 15 of the anti-static chamber 14 . The four connection points 51 a , 51 b , 53 a , 53 b include first and second connection points 51 a , 51 b formed in lateral side walls 70 in the second housing leg 26 below the slot 120 . In particular, the lateral side walls 70 include upper edges 90 which are parallel to each other and extend along a path substantially parallel to the a longitudinal axis of the second housing leg 26 . Consequently, the upper edges 90 define support surfaces, that is, connection points 51 a , 51 b , upon which the outer wall of the anti-static chamber 14 may rest.
The anti-static chamber clip 50 is further provided with third and fourth connection points 53 a , 53 b defined by protrusions 57 a and 57 b on an upper portion of lateral side walls 70 formed extending along the first housing leg 24 above the slot 120 . The third and fourth connection points 53 a , 53 b formed by protrusions 57 a , 57 b define substantially linear contact surfaces 95 substantially parallel to and facing the first and second connection points 51 a , 51 b . As such, the upper edges 90 and contact surfaces 95 of protrusions 57 a , 57 b define the clip recess 100 in which the anti-static chamber 14 is positioned for coupling with the inhaler assist device 10 . The spacing between the first, second, third and fourth connection points 51 a , 51 b , 53 a , 53 b is such that the first end of the anti-static chamber 14 may be positioned therein with the connection points frictionally engaging the outer wall of the coupled end 15 of the anti-static chamber 14 .
As briefly mentioned above, the lateral side walls 70 include a slot 120 which permits the anti-static chamber clip 50 to flex outward such that the four connection points 51 a , 51 b , 53 a and 53 b can grip a larger diameter anti-static chamber 14 . As shown, the lateral side walls 70 are not flexed, but due to the slots 120 the lateral side walls 70 can flex outward, that is, with the second housing leg 26 moving away from the lever actuator 18 , to accommodate a larger diameter anti-static chamber 14 which are still retained by the four connection points 51 a , 51 b , 53 a and 53 b.
Turning now to the lever actuator 18 , the first end 20 of the lever actuator 18 is pivotally connected to the first end 30 of the first housing leg 24 . As mentioned above, the junction of the first end 20 of the lever actuator 18 with the first end 30 of the first housing leg 24 defines the concave recess 38 shaped and dimensioned for placement of the base, or second, end 60 of the metered dose inhaler 12 while the dispensing, or first, end 62 of the metered dose inhaler 12 extends downward substantially in parallel alignment with the first housing leg 24 which ultimately joins the second end 36 of the second housing leg 26 . While the concave recess 38 supports the base 60 of the metered dose inhaler 12 , the lever actuator 18 is provided with an inwardly extending second cross member 76 for engaging the base 60 of the metered dose inhaler 12 .
In practice, the first end of the anti-static chamber 14 (with the metered dose inhaler 12 secured thereto) is secured to the anti-static chamber clip 50 such that the longitudinal axis of the anti-static chamber 14 is in substantially parallel alignment with the longitudinal axis of the second housing leg 26 as it extends from its first end 34 to its second end 36 . The metered dose inhaler 12 is thereby positioned within the recess defined by the base wall 54 and lateral side walls 70 along the second housing leg 26 .
With the anti-static chamber 14 securely coupled to the housing assembly 16 , the lever actuator 18 is rotated toward the second housing leg 26 until such a time that the base 60 of the metered dose inhaler 12 seats within the concave recess 38 . The distance from the upper support surface 82 of the shelf 80 formed at the second end 36 of the second housing leg 26 to the base wall 44 of the lever actuator 18 adjacent the concave recess 38 is substantially the same as the length of the metered dose inhaler 12 . As such the metered dose inhaler 12 fits snuggly between the second end 36 of the second housing leg 26 and the concave recess 38 , in particular, the second cross member 76 of the lever actuator 18 , when the lever actuator 18 is in its starting position (that is, the positioned of the lever actuator 18 when the metered dose inhaler 12 is loaded but the metered dose inhaler 12 has not been actuated for dispensing of a dose).
With the lever actuator 18 in its start position and the metered dose inhaler 12 positioned between the second end 36 of the second housing leg 26 and the concave recess 38 adjacent the first end 20 of the lever actuator 18 , the user places his or her mouth over the discharge opening 68 of the anti-static chamber 14 and squeezes the second end 22 of lever actuator 18 toward the second housing leg 26 . This will cause the application of pressure to along the length of the metered dose inhaler 12 causing the discharge of medicine therefrom.
While the preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention.
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The present invention is directed to an inhaler assist device shaped and dimensioned for supporting a metered dose inhaler and an associated anti-static chamber in a manner allowing for assisted compression of the metered dose inhaler to dispense a dosage therefrom. The inhaler assist device includes an L-shaped housing assembly pivotally connected to a lever actuator. The housing assembly includes a planar base wall and lateral side walls extending from base wall, wherein the base wall and the lateral side walls create a cavity shaped and dimensioned for receipt of the metered dose inhaler and an anti-static chamber.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/753,307 filed on Jan. 16, 2013, the entire contents of which are herein incorporated by reference.
BACKGROUND AND SUMMARY
A post hole digger attaches to the standard three point hitch of the tractor is powered by the tractor's power take-off (PTO). The digger comprises an auger without protrusions or other extending parts above the fighting of the auger, to reduce the possibility of a user becoming ensnared during use of the digger.
A gearbox translates rotation from the PTO shaft to the auger. In a traditional post hole digger, the auger's shaft attaches to the gearbox via a cross bolt that extends perpendicularly through the shaft. The cross bolt has the disadvantage of protruding from the shaft, and causing potential harm to a user. The digger of the present disclosure removes this disadvantage by providing a threaded fitting between the shaft and the gearbox. However, a threaded fitting on the rotating shaft provides an additional challenge When the auger needs to be removed from the gearbox.
The gearbox lock mechanism of the present disclosure comprises a collar coupled to a lower end of the gearbox, the collar rotatable upon operation of the gearbox. The collar comprises a semi-circular outer edge and a flat side. A male-threaded nipple extends from the collar and threads into the auger shaft. A lock bar is coupled to the gearbox and acts as a positive lock to lock the collar in place for removal of the shaft from the gearbox. The lock bar is rotatable from a locked position whereby the lock bar is aligned with and contactable with the flat side of the outer edge of the collar, to an unlocked position whereby the lock bar does not contact the flat side of the outer edge of the collar.
For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a side plan view of a post hole digger coupled to a tractor.
FIG. 2 is a rear perspective view of the post hole digger of FIG. 1 .
FIG. 3 is a bottom perspective view of the digger.
FIG. 4 is an enlarged detail view of the digger of FIG. 3 , taken along detail line A of FIG. 3 .
FIG. 5 is a rear plan view of the digger of FIG. 1 .
FIG. 6 is an enlarged detail view of the digger of FIG. 5 , taken along detail line B of FIG. 5 .
FIG. 7 is a cross sectional view of the digger of FIG. 6 , taken along section lines C-C of FIG. 6 .
FIG. 8 is a partial enlarged bottom view of the digger of FIG. 6 .
DETAILED DESCRIPTION
FIG. 1 is a side plan view of a post hole digger 10 . The digger 10 is shown installed on a tractor 7 and is used to dig generally-cylindrical holes (not shown) in the ground 8 , for example, holes for fence posts. The digger 10 is disposed at the rear of the tractor 7 between the rear wheels 9 a and 9 b ( FIG. 2 ) of the tractor 7 .
The digger 10 comprises an auger 13 for drilling into the ground 8 . The digger 10 is disclosed in U.S. Non-Provisional Patent Application Serial No. 13/548,836, titled “Post Hole Digger,” published on Jan. 17, 2013, under Publication No. US-2013-0014997-A1, which is incorporated herein by reference in its entirety.
The auger 13 is supported by a top support arm 18 that extends from the tractor 7 . A rotating shaft 17 extends from a PTO shaft 20 ( FIG. 2 ) of the tractor 7 and translates rotation from the PTO shaft 20 to a gearbox 12 , and ultimately to the auger 13 . A shield 19 covers moving parts (not shown) of the gearbox 12 that could otherwise pose a safety hazard to users not shown) of the digger 10 .
FIG. 2 is a rear perspective view of the digger 10 installed on the tractor 7 between the rear wheels 9 a and 9 b of the tractor 7 . The digger 10 connects to the tractor's standard three point hitch that is known in the art. The term “three point hitch” refers to the three mounting points of a tractor hitch that extend rearwardly from the rear of the tractor 7 .
The top support arm 18 is rotatably affixed to the shield 19 that covers the gearbox 12 . A support frame 25 supports the top support arm 18 . The shield 19 is rigidly affixed to the gearbox 12 , and is not detachable from the digger in this embodiment without making the digger non-fictional, to provide safety for the user.
The rotating shaft 17 is releasably coupled to the PTO shaft 20 of the tractor 7 . As known by persons of skill in the art, a power-take off shaft is a splined shaft that is rotatable by the user (not shown) upon actuation of the tractor controls (not shown). Rotation of the PTO shaft 20 typically powers farming implements such as the digger 10 . The rotating shaft 17 extends from the PTO shaft 20 to the gearbox 12 , as further discussed herein.
The gearbox 12 is a right angle gearbox that receives rotation from the rotating shaft 17 and translates the received rotation to the auger 13 . In this embodiment, the auger 13 comprises a rotatable auger shaft 33 , a plurality of fighting blades 14 and a cutting head 15 . The cutting head 15 is disposed at the lowermost end of the shaft 33 , and comprises a pilot bit 16 and a pair of cutting blades 34 . The fighting blades 14 are disposed above the cutting head 15 .
The outer surface of the shaft 33 is generally smooth above the fighting blades 14 , and has no protrusions or other irregularities above the fighting blades 14 that may ensnare or entangle a user during use. This is an improvement over prior art augers which contain protrusions from the shaft that can endanger a user.
FIG. 3 is a bottom perspective view of the digger 10 . The gearbox 12 is disposed beneath the shield 19 , The auger 13 comprises a shaft 33 that extends from the gearbox 12 . Between the gearbox 12 and the flighting 14 , the shaft 33 is smooth, i.e., has no protrusions that could catch on a user or the user's clothing.
FIG. 4 is an enlarged detail view of the digger 10 of FIG. 3 , taken along detail “A” of FIG. 3 . A collar 63 extends beneath the gearbox and is rigidly affixed to a male-threaded nipple 64 that releasably affixes the shaft 33 to the gearbox 12 . In the illustrated embodiment the collar 63 is unitary with the nipple 64 . The collar has a semi-circular outer edge 65 that is primarily semi-circular and has a flat side 66 . The collar 63 , threads 64 and shaft 33 rotate when the digger 10 ( FIG. 1 ) is in operation.
A lock bar support 61 is coupled to the gearbox 12 between the collar 63 and the gearbox 12 . The lock bar support 61 does not rotate. A lock bar 60 is rotatably coupled to the lock bar support 61 via a fastener 62 .
When the digger 10 is in operation, the lock bar 60 is in an “unlocked” position such that the lock bar 60 extends downwardly. When the user desires to remove the auger 13 ( FIG. 3 ) from the gearbox 12 , the user manually moves the lock bar 60 to a “locked” position such that the lock bar 60 is rotated upwardly until it contacts the lock bar support 61 . In this orientation, the lock bar 60 is generally parallel to the flat side 66 of the collar 63 . When the lock bar 60 is in the locked position, the flat side 66 contacts the lock bar 60 and prevents the collar 63 from rotating. Thus the term “locked” refers to the collar 63 being locked such that it cannot rotate, and the term “unlocked” refers to the collar being rotatable. When the collar 63 is locked, the user can remove the auger 13 from the digger 10 by unscrewing the shaft 33 from the threaded nipple 64 .
FIG. 5 is a rear plan view of the digger 10 of FIG. 1 . The lock bar support 61 is rigidly coupled to a bottom side 68 of the gearbox 12 . In one embodiment, the lock bar support 61 is affixed to the gearbox 12 via a plurality of fasteners (not shown). The lock bar support 61 is generally parallel to the collar 63 . The lock bar 60 extends downwardly from the lock bar support 61 when the lock bar 60 is in its unlocked position, as shown. In this unlocked position, the lock bar 60 is generally perpendicular to the lock bar support 61 and the collar 63 .
FIG. 6 is an enlarged detail view of the digger 10 of FIG. 5 , taken along detail line “B” of FIG. 5 . The lock bar 60 is shown in its unlocked position. From this unlocked position, the lock bar 60 is rotatable upwardly in the directly indicated by directional arrow 67 . The lock bar 60 is generally rectangular, with long opposed sides extending downwardly when it is in the unlocked position.
The lock bar support 61 is comprised of a generally fiat support plate 82 and a downwardly extending tab 80 that is generally perpendicular to the support plate 82 . The lock bar 60 is rotatably affixed to the tab 80 via the fastener 62 , which may be a bolt and nut. The support plate 82 and tab 80 are made of steel in one embodiment, though other suitably strong and rigid materials could be used.
FIG. 7 is a cross sectional view of the digger 10 of FIG. 6 , taken along section lines C-C of FIG. 6 , with the lock bar 60 shown in its unlocked position. In this position, the lock bar 60 cannot contact the collar 63 , thus the collar 63 is free to rotate. The support plate 82 of the lock bar support 61 is a curved plate with a generally flat cross section and is coupled to the gearbox 12 via a plurality of fasteners 74 . Note that the support plate 82 is coupled to the non-rotatable outer body of the gearbox 12 , in contrast with the collar 63 , which rotates upon operation of the gearbox 12 . The support plate 82 extends over halfway around the gearbox 12 when viewed from the bottom as shown.
The lock bar support 61 further comprises a block stop 81 that is rigidly affixed to the support plate 82 adjacent to the lock bar 60 when the lock bar 60 is in the locked position. The block stop 81 comprises a generally rectangular box, generally made of steel, that is substantially parallel to and spaced apart from the flat side 66 of the collar 63 when the collar 63 is locked. The block stop 81 being spaced apart from the flat side 66 creates a gap 75 between the block stop 81 and flat side 66 . The width of this gap 75 , i.e., the distance “D” between an inner surface 83 of the block stop 81 , is slightly larger than a width “W” of the lock bar 60 . This is desired because when the lock bar 60 is locked, it is disposed between the inner surface 83 of the block stop 81 and the flat side 66 of the collar 63 .
The outer edge 65 of the collar 63 comprises the flat side 66 and a semi-circular portion 68 that extends more than 270 degrees around the collar. In other words, the flat side 66 in effect “cuts off” the outer edge 65 , generally less than 90 degrees around the outer edge 65 . Corners 70 and 71 on the outer edge 65 provide a transition from the semi-circular portion 68 to the flat side 66 of the outer edge 65 .
Note that the distance “D” must be sufficient so that the semi-circular portion 68 of the outer edge 65 of the collar 63 clears the block stop 81 when the lock bar 60 is in the unlocked position.
When the lock bar 60 is locked, the lock bar 60 is generally parallel to the flat side 66 of the collar 63 and the inner surface 83 of the block stop 81 . If the collar 63 is urged to rotate in either direction indicated by directional arrow 73 , one of the corners 70 or 71 will contact an inner side (not shown) of the lock bar 60 and prevent the collar 63 from further rotation, thus providing a positive lock to prevent the collar from rotation.
FIG. 8 is a partial enlarged view of the digger 10 showing a bottom perspective view of the gearbox 12 . The block stop 81 is spaced apart from the flat side 66 of the collar 63 as discussed above, creating the gap 75 . The lock bar 60 is disposed within the gap 75 , and generally contacts the support plate 82 when the lock bar 60 is in the locked position.
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The gearbox lock mechanism for a post bole auger has a collar coupled to a lower end of a right angle gearbox, the collar rotatable upon operation of the gearbox. The collar comprises a semi-circular outer edge and a fiat side. A male-threaded nipple extends from the collar and threads onto the auger shaft. A lock bar is coupled to the gearbox and acts as a positive lock to lock the collar in place for removal of the shaft from the gearbox. The lock bar is rotatable from a locked position whereby the lock bar is aligned with and contactable with the flat side of the outer edge of the collar, to an unlocked position whereby the lock bar does not contact the flat side of the outer edge of the collar.
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BACKGROUND
[0001] The present invention relates to a device and a method for identifying materials in a scene. More particularly, the present invention relates to such devices and methods capable of rapidly identifying materials in a scene, for example, on an assembly line.
DISCUSSION OF THE RELATED ART
[0002] On assembly of printed circuits, many alignment and positioning tests are performed at different stages of the assembly. Particularly, a first alignment and positioning test is currently performed after the forming of solder pads on a printed circuit board. This first test enables to determine whether the pads are properly distributed at the board surface.
[0003] Components or chips are then positioned on the printed circuit board so that their terminals coincide with solder pads. A second alignment and positioning test may be performed after this component positioning step. A last step comprises annealing the structure to melt the solder pads so that the components or chips are held in position on the integrated circuit board.
[0004] In a conventional assembly method, the integrated circuit boards are placed on a conveyor and the assembly steps are performed sequentially. Many devices for testing boards positioned on conveyors are known, particularly devices integrating optical inspection elements.
[0005] It would be however advantageous to also identify the materials present in the scene. Identification of a material here indifferently means determining a group of materials comprising the material to be identified, that is, for example the nature of the material (dielectric, conductor . . . ), determining the actual material (copper, aluminum . . . ), or making a distinction between different surface conditions of a same material (a plurality of roughness or oxidation levels, for example).
[0006] It has already been provided to identify materials by performing color detections in a two-dimensional scene. A disadvantage is that the result is relatively dependent on lighting conditions. Further, such a method is limited as to the number of materials which can be detected. It is further poorly adapted to an identification of materials in a three-dimensional scene, shadows of raised elements being capable of distorting the identification.
[0007] There thus is a need for a relatively fast method and device for identifying materials in a scene, that is, capable of performing identifications on mobile scenes, and particularly on an assembly line.
SUMMARY
[0008] An object of an embodiment is to provide a device and a method for identifying materials in a scene.
[0009] Another object of an embodiment is to provide a particularly fast solution adapted to mobile scenes, particularly on an assembly line.
[0010] Another object of an embodiment is to provide a device and a method capable of identifying materials in a three-dimensional scene.
[0011] To achieve all or part of these and other objects, the present invention provides a method of identifying a material in a scene, comprising the steps of: lighting the scene; taking at least two simultaneous measurements of the light amplitude of the scene for different states of light polarization by means of at least two measurement devices positioned along directions inclined above the normal of the scene; and deducing an identification of the material therefrom.
[0012] An embodiment of the present invention further provides a system for identifying a material in a scene, comprising at least one element of a first type selected from among a light source and an image acquisition device and at least two elements of a second type, different from the first type, selected from among an image acquisition device and a light source, each second element being associated with a rectilinear polarizer in a fixed relationship.
[0013] According to an embodiment of the present invention, the optical axis of each element of the second type forms, with respect to the optical axis of the element of the first type, an angle in the range from 5 to 50°, the elements of the second type being regularly distributed around the optical axis of the element of the first type.
[0014] According to an embodiment of the present invention, the image acquisition device(s) acquire images of the light amplitude of the scene for different light polarization states.
[0015] According to an embodiment of the present invention, the system further comprises a processing device capable of identifying, based on the images acquired by the image acquisition device(s), a material in the scene.
[0016] According to an embodiment of the present invention, the system further comprises a device for determining the topology of the scene, the processing device receiving information from the determination device.
[0017] According to an embodiment of the present invention, the element of the first type is placed along an axis normal to the plane of the scene.
[0018] According to an embodiment of the present invention, the elements of the second type are light sources.
[0019] An embodiment of the present invention further provides a method such as described hereabove, implementing the system such as described hereabove, wherein the light sources are alternately activated, the image acquisition device being provided to acquire an image for each source activation alternation.
[0020] An embodiment of the present invention further provides an installation comprising a part conveyor and a system for identifying a material in the parts such as described hereabove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings, among which:
[0022] FIG. 1 illustrates a printed circuit board inspection device;
[0023] FIG. 2 illustrates a known device for identifying materials present in a two-dimensional scene (2D);
[0024] FIG. 3 is a curve illustrating the principle of a device according to an embodiment;
[0025] FIG. 4 is a block diagram of a system according to an embodiment;
[0026] FIG. 5 is a perspective view illustrating notations used to describe embodiments;
[0027] FIG. 6 illustrates an embodiment of an element of the system according to an embodiment;
[0028] FIG. 7 illustrates another embodiment of an element of the system according to an alternative embodiment;
[0029] FIG. 8 illustrates another embodiment of an element of the system according to an alternative embodiment; and
[0030] FIGS. 9 and 10 show, in the form of block diagrams, embodiments of a method for identifying a material in a scene.
[0031] For clarity, the same elements have been designated with the same reference numerals in the different drawings and, further, as usual in the representation of test systems, the various drawings are not to scale.
DETAILED DESCRIPTION
[0032] FIG. 1 schematically shows an example of such an installation, such as described in documents EP-A-2413132 and US-A-2012/019651. Electronic circuits IC, for example supported by a printed circuit board ICC, are placed, for example, on a conveyor 1 of an in-line optical inspection installation. The installation comprises a system 2 of digital cameras, connected to an image processing computer system 3 . Conveyor 1 is capable of moving in a plane X, Y (generally horizontal) and, for a series of photographs, in one of the two directions only, that is, direction X.
[0033] Digital camera system 2 may take a plurality of forms. It has in particular been provided to detect the positioning of chips or of components on a printed circuit board by a detection of shapes at the board surface, that is, by a detection of the three-dimensional structure of the device. If a component, a chip, or a solder pad is not properly positioned, this can be detected by comparing the board topology with a reference topology.
[0034] FIG. 2 illustrates a known device for identifying materials present in a two-dimensional scene (2D).
[0035] The device comprises a wafer 12 having patterns 14 made of a material from that of the wafer, and which is desired to be identified, formed at its surface. Wafer 12 is for example illuminated by ambient light. A camera 16 is placed opposite wafer 12 and is positioned to acquire an image of at least a portion of the surface of wafer 12 , the structure of which is desired to be identified by the identification of the material. In the shown example, the optical axis of the camera is orthogonal to the wafer surface. It should be noted that an oblique positioning of the camera is also possible.
[0036] A rotating linear polarizer 18 is placed in front of camera 16 . Polarizer 18 may for example be formed of a bi-refringent lens which amplifies the light intensity along a light polarization axis and attenuates the light intensity along another light polarization axis, orthogonal to the first axis. The camera is associated with processing and calculation means 20 .
[0037] The rotating linear polarizer is used as an ellipso-meter. This enables to map the light intensity according to the direction of the polarization. To perform this mapping, the rotating linear polarizer may for example be assembled on a motor-driven shaft.
[0038] It should be noted that a similar detection may be performed by means of a device comprising an association of two linear polarizers positioned around a voltage-controlled liquid crystal time delay unit.
[0039] FIG. 3 illustrates a result capable of being obtained by the device of FIG. 2 . More particularly, FIG. 3 illustrates two ellipsometric curves determined by means of the device of FIG. 2 , originating from measurements performed for two pixels of the camera directed towards points of the scene made of different materials. These curves illustrate the modulation coefficient of the incident intensity according to the rotating polarizer angle (in radian) for a first pixel of the camera which is directed towards a first material at the surface of support 12 (curve 22 ) and for a second pixel of the camera which is directed towards a second material at the surface of support 12 (curve 24 ).
[0040] As can be seen in FIG. 3 , curves 22 and 24 have different amplitudes over the possible polarization angles. In the shown example, curve 22 corresponds to the acquisition performed by a pixel of camera 16 which detects an area of a conductive material, and more particularly of copper. Curve 24 corresponds to the acquisition performed by a pixel of camera 16 which detects an area of a dielectric material.
[0041] Measurements such as that of FIG. 2 can thus be used to obtain information relative to the material having reflected the light wave. Indeed, each material has an ellipsometric signature linked to its composition, and particularly to its refraction index. A comparison between an ellipsometric signature and reference signatures enables to determine the associated material.
[0042] However, an identification of materials by ellipsometry cannot be implemented in the case of the processing of a mobile scene, for example, on an assembly line, where the time allowed for each acquisition is decreased. Indeed, to perform an identification by ellipsometry and thus by comparison of ellipsometric curves, the measurement of many points for different positions of the rotating linear polarizer is necessary, such a measurement being time-consuming. An identification of materials by ellipsometry can further not be implemented in the case of a processing of a deformable scene having an unknown topology. The use of a structure comprising two polarizers coupled to a liquid crystal time delay unit also implies a measurement time prohibitive for an application on an assembly line.
[0043] According to an embodiment, the system for identifying materials in a scene comprises no variable polarization device. A variable polarization device is a device capable of polarizing a light beam which crosses it with a polarization which varies along time. It for example is a rotating linear polarizer such as previously described. According to an embodiment, each polarizer used in the identification system is in a fixed relationship with the image acquisition device or the light source associated therewith. The identification system comprises no optical beam splitter either.
[0044] FIG. 4 is a block diagram illustrating a system according to an embodiment enabling to identify materials in a scene, compatible with an identification on an assembly line.
[0045] A measurement device 26 (POLA) detects, for each elementary area of the scene, the light amplitude reflected by this area for at least two different light polarization states. The system comprises a processing and calculation device 27 (PROCESSING) which, based on the data delivered by system 26 , provides an identification of the material present in the elementary area of the scene.
[0046] The system further comprises a device for determining the topology of scene 28 (3D). In the following description, scene topology designates a description of the relief of the scene. The determination of the scene topology may comprise determining a three-dimensional image of the scene. A three-dimensional image corresponds to a cloud of points, for example, comprising several million points, of at least a portion of the external surface of the scene, where each point of the surface is located by its coordinates determined with respect to a three-dimensional space reference system.
[0047] In the case of a three-dimensional scene, due to the presence of the device for determining the topology of scene 28 , the value of the vector normal to the surface of the scene {right arrow over (N)} is known at any point in the scene. To determine the scene topology, various devices may be used. Systems such as those described in patent application US 2012/019651 of the applicant may in particular be used. This device comprises, in a plane orthogonal to the forward direction of a conveyor, a set of two projectors, each projector being associated with a plurality of cameras to obtain a 3D image capture system. Calculation and processing means apply a super-resolution process to the obtained data.
[0048] Of course, other devices for determining the topology of the 3D scene may also be used as device 26 .
[0049] Device 26 for determining the scene topology may correspond to a device different from measurement device 26 . As a variation, at least certain elements of the device for determining the topology of scene 28 , particularly cameras and/or projectors, may be common with measurement device 26 .
[0050] In another embodiment, the scene topology and the position of the scene relative to the acquisition devices may originate from a digital description file and correspond to a theoretical topological representation of the scene.
[0051] The reflection of a light wave on a surface implies a variation of the polarization of the wave having its amplitude depending, apart from refraction index η of the detected material, on the geometry of the analyzed surface, on roughness r of the surface, and on wavelength λ of the light beam illuminating the surface. Roughness r of the surface and wavelength λ of the light beam illuminating the surface will be neglected or assumed to be constant in the present case.
[0052] The geometry of the analyzed surface may be characterized by a vector {right arrow over (N)} normal to the analyzed surface. Thus, the polarization state of a light wave reflected on a surface depends on the polarization state of the initial wave projected on the surface, on parameters {right arrow over (N)}, r, and λ, and on refraction index η of the material.
[0053] Amplitude I(η, θ′, α, β) of the light diffused by a material located in a three-dimensional scene and measured by a sensor positioned behind a rotating linear polarizer may be written according to the following relation (1):
[0000]
I
(
η
,
θ
′
,
α
,
β
)
=
I
d
2
[
(
a
-
cos
(
θ
′
)
)
2
+
b
2
(
a
2
+
b
2
)
tan
(
θ
′
)
2
+
2
a
·
cos
(
θ
′
)
tan
(
θ
′
)
2
+
2
(
a
2
+
b
2
)
+
sin
(
θ
′
)
2
tan
(
θ
′
)
2
cos
(
2
(
α
-
β
)
)
+
1
]
with
:
2
a
2
=
n
2
-
k
2
-
sin
(
θ
′
)
2
+
4
n
2
k
2
+
n
2
-
k
2
-
sin
(
θ
′
)
2
2
b
2
=
n
2
-
k
2
-
sin
(
θ
′
)
2
+
4
n
2
k
2
-
n
2
-
k
2
-
sin
(
θ
′
)
2
(
1
)
[0000] n and k respectively being the real part and the imaginary part (absorption index) of refraction index η of the material, a pair (θ, α) representing the first two spherical coordinates (zenith and azimuth) of normal {right arrow over (N)} to the surface observed in the camera reference system, angle θ′ being the angle of the radius refracted in the material, obtained from angle θ by applying the Snell-Descartes law (sin(θ)=n·sin(θ′)), and β being the polarizer angle.
[0054] FIG. 5 schematically illustrates the different angles mentioned in the above formula. This drawing shows a light source S which illuminates the surface of a material M. The beam reflected by an elementary portion of surface M towards a detector or a camera D is here considered, a polarizer P being placed on the path of the wave reflected by the material.
[0055] Reference system (x, y, z) of the camera is defined so that axis z coincides with the direction of the beam reflected by material M. Angle β of polarizer P is defined in the present example as being the angle formed, in a plane normal to direction z, with axis y. Angle θ is the angle formed between direction z and the direction of normal {right arrow over (N)} to the surface of material M, and angle α is the angle formed between a projection of normal {right arrow over (N)} in a plane (x, y) and axis y of this plane.
[0056] It should be noted that the diffuse component of the beam is here considered, which is, in the Fresnel model, a component transmitted by the inner layer of the material. I(1/η, θ′, α, β) should thus be used to express the intensity measured by the sensor.
[0057] It is here provided to perform, by means of measurement device 26 , a plurality of acquisitions of the amplitude of the light reflected by the different materials in the scene, for different polarization states of this light. Be the scene two-dimensional (normal vector {right arrow over (N)} orthogonal to the scene surface) or three-dimensional, the device provided herein has the same operation.
[0058] Measurement system 26 is provided to obtain at least two pieces of information relative to the modification of the light beam by the reflection on the pixel, and this for at least two polarization states, as will be seen hereafter.
[0059] In particular, if it is desired to determine the nature of the materials present in the scene, for example, dielectric or conductive, a small quantity of information relative to the amplitude of the light beam by reflection on the pixel is necessary. Indeed by properly specifying the polarization states which are detected, the amplitude variation on the material can be determined, such a variation being directly linked to the nature of the material. If more accurate information relative the material is desired, for example, if the refraction index thereof is desired to be determined, four acquisitions of different polarization states may be necessary.
[0060] FIG. 6 illustrates in further detail an embodiment of a measurement system 26 of FIG. 4 .
[0061] Measurement system 26 comprises a projector 30 having its optical axis extending along a direction normal to the direction of the scene to be analyzed.
[0062] In the shown example, system 26 further comprises a set of four cameras 32 (four acquisitions in parallel) placed to acquire, from different viewpoints, an image of the scene centered on a same point. The point at the center of the images acquired by cameras 32 may be confounded with the center of the beam provided by projector 30 . As an example, cameras 32 may be inclined according to a same angle α with respect to the optical axis of the projector and be regularly positioned around the optical axis of projector 30 . Angle α formed between the optical axis of cameras 32 and the optical axis of cameras 30 may be in the range from 5 to 50°. It should be noted that a significant angle improves the quality of the identification. It should also be noted that more or less than four cameras may be provided, as described hereabove. According to a variation, angle α may be different for each camera.
[0063] A rectilinear polarizer 34 fixed with respect to each of the cameras is placed in front of each of cameras 32 . Processing and calculation device 27 (not shown in FIG. 6 ) receives the acquisitions of the different cameras and identifies, for each pixel of the scene, by means of the knowledge of the pixel topology, the material present at the level of the pixel of the scene.
[0064] A plurality of configurations of the rectilinear polarizers in front of each of the cameras is possible, what matters being for the cameras to have different points of view on the scene. Indeed, this causes variations of the intensities measured by the different cameras. Rectilinear polarizers 34 may be placed in front of each of the cameras to have a same polarimetry configuration, that is, the polarization angles of the polarizers are rotationally symmetrical around the optical axis of projector 30 . If the variation of the intensities measured by the different cameras is desired to be increased, the angles of the polarizers may also be shifted between cameras. Indeed, a polarimetric configuration varying between the cameras provides a good quality identification.
[0065] The preferred position of the rectilinear polarizers provided hereabove enables to perform measurements of the light amplitude reflected by each pixel of the scene for different polarization states of the reflected light (each camera is associated with a linear polarizer, which ensures the measurement of the different polarization states). Thus, the cameras each receive, for a same pixel of the scene, a light amplitude corresponding to a different polarization of the light reflected by the pixel. Based on values measured by the cameras for different light polarization states and on the knowledge of the scene topology in the case of a 3D scene, the materials present in the scene can thus be determined (by determination of their refraction indexes).
[0066] FIGS. 7 and 8 illustrate two alternative embodiments of a device according to an embodiment.
[0067] FIG. 7 shows a device similar to that of FIG. 6 in that it comprises a projector 30 of non-polarized light positioned along a direction normal to the scene, the light emitted by the projector being capable of illuminating at least a portion of the scene which is studied. In the example of FIG. 7 , two cameras 32 , associated with rectilinear polarizers, acquire images of the scene. The two cameras 32 are placed symmetrically with respect to the projector, the optical axis of the cameras forming an angle α with the optical axis of the projector, preferably in the range from 5 to 50°.
[0068] It will be within the abilities of those skilled in the art to select the polarizations to be imposed to the two polarizers 34 , so that they detect, for a planar reference surface, the maximum and minimum values of the detected intensity.
[0069] FIG. 8 illustrates another alternative embodiment. An association of two light sources and of a camera is provided in FIG. 8 , for a result similar to the embodiments of FIGS. 6 and 7 .
[0070] In the example of FIG. 8 , two light sources 30 A, 30 B are placed to illuminate, at the level of their optical axes, a same point of the scene. The optical axis of the two light sources are provided with respect to the normal to the scene to form a same angle α, preferably in the range from 5 to 50°, and are oriented symmetrically with respect to a plane normal to the scene. A single camera 32 is placed in this normal plane, and its optical axis is directed towards the central point of the light beams originating from sources 30 A and 30 B.
[0071] Light sources 30 A, 30 B are polarized. To schematize this point in FIG. 7 , two polarizers 34 A, 34 B, fixed with respect to sources 30 A, 30 B and placed on the optical path of the beam originating from sources 30 A, 30 B. It should be noted that polarized light sources may also directly be provided.
[0072] The polarizations of the light beams of sources 30 A and 30 B (or the positioning of polarizers 34 A and 34 B in the example of FIG. 7 ) may be provided to limit specular reflections, which may be disturbing in the vision system. The polarizations of the light beams of sources 30 A and 30 B (or the positioning of polarizers 34 A and 34 B in the example of FIG. 7 ) may also be selected so that the signal reflected by a planar reference surface is received by the camera to coincide with the detected light amplitude extreme (cure of FIG. 3 ).
[0073] In operation, it may be provided to alternately illuminate the scene by means of projectors 30 A and 30 B, the camera performing a first acquisition under the illumination of projector 30 A and a second acquisition under the illumination of projector 30 B. In the case of a batch processing, on an assembly line, the acquisition delay between the first and second acquisition may be provided to be corrected so that the images detected during these two acquisitions are comparable.
[0074] The amplitude information detected by the camera during the two phases of activation of projectors 30 A and 30 B for a same area of the scene, as well as the knowledge of the topology of this area if the scene is three-dimensional, enable processing system 27 to identify the pixel material.
[0075] According to a variation of the embodiment shown in FIG. 8 , polarizers 34 A and 34 B are not present. A rectilinear polarizer fixed with respect to camera 32 is placed in front of camera 32 . The camera performs a first acquisition under the illumination of projector 30 A and a second acquisition under the illumination of projector 30 B. The different polarization states of the two acquisitions are then due to the fact that the scene is illuminated under a different angle by each projector 30 A, 30 B during the acquisitions. Thus, a single or none of the projectors may be equipped with an optical device modifying the incident polarization state.
[0076] It should be noted that different variations may be obtained based on the embodiments of FIGS. 6 to 8 . Indeed, it may be provided to use numbers of light sources and of cameras different from those provided herein, as long as at least two emitting source/receiver pairs are provided in the device (at least one source for two cameras or two sources for one camera).
[0077] Of course, it should be understood that the larger the number of source/sensor pairs, the fine and more accurate the detection of the materials can be.
[0078] In practice, the number of materials to be identified in the scene may be limited. Indeed, for example, in the case of an application of the method to the identification of materials in an assembly line for printed circuits assembled on a board, it may be desired to only make the difference between conductive materials (for example, the chip interconnection copper tracks) and dielectric materials. Advantageously, such materials have very different ellipsometric signatures (light amplitude variation more significant for conductive materials than for insulating materials), which enables to distinguish between these materials. The narrowing of the selection of materials in a list enables, as seen previously, to limit the number of light source/acquisition device pairs of the identification system.
[0079] Advantageously, the structure for identifying materials in a scene provided herein may be integrated in devices for detecting the 3D topology of a scene, and particularly with the device described in US 2012/019651 patent application mentioned hereabove. To achieve this, it is sufficient to make another use of the function of certain cameras of the scene, for the identification of materials rather than for topology detection, or also to add one or a plurality of cameras dedicated to the identification of materials in the topology detection system.
[0080] According to an embodiment, the method of identifying a material in a scene comprises directly comparing to each other the acquired images corresponding to two different polarization states.
[0081] FIG. 9 shows, in the form of a block diagram, an embodiment of a method of identifying a material in a scene.
[0082] At step 40 , device 28 determines the topology of the scene. This may comprise determining a three-dimensional image of the scene. A three-dimensional image corresponds to a cloud of points, for example, comprising several million points, of at least a portion of the external surface of the scene, where each point of the surface is located by its coordinates determined with respect to a three-dimensional space reference system.
[0083] At step 42 , processing and calculation device 27 determines, for each point of interest of the observed scene, the light intensities measured by all the cameras of measurement device 26 observing this point of interest. Point of interest means one of the points of the scene having its position known due to the scene topology data and for which the corresponding material is desired to be identified. The positions of the image point corresponding to the point of interest in the acquired images are given by the combination of the scene topology data delivered by device 28 with, for example, information relative to the calibration of the image acquisition devices enabling to project the points originating from the topology into the acquired images.
[0084] For each point of interest of the observed scene, processing and calculation device 27 determines, in each image acquired at different polarization states by the cameras observing this point of interest of the scene, the light intensity at the image point, for example, by bilinear interpolation based on the light intensities of the pixels of an image portion around the image point.
[0085] At step 44 , processing and calculation device 27 compares the light intensities determined at step 42 for a given point of interest. This comparison may for example be made in the form of a simple difference of the light intensities or of the ratio of the light intensities. Generally, the comparison state shows the variations of the light intensity according to the polarization state of the acquired images.
[0086] At step 46 , processing and calculation device 27 determines the nature at the point of interest of the scene from the value of the difference determined at step 44 . As an example, this may be obtained by comparing the difference with a threshold. When the difference is greater than or equal to the threshold, device 7 determines that the point of interest of the scene is made of a conductive material and, when the difference is strictly smaller than the threshold, device 7 determines that the point of interest of the scene is made of a dielectric material. The threshold used may be experimentally determined from known scenes.
[0087] When more than two images of the scene with different polarization states are acquired, step 42 comprises, based on the scene topology data delivered by device 28 , determining the different light intensities for each point of interest. As an example, this determination may be performed in two steps. The first step comprises projecting the point of interest of the scene on the image plane of all the cameras to obtain the corresponding image points. The second step comprises interpolating the light intensities at each image point, for each acquired image. Step 46 may comprise a step of comparing the identifications of the nature of the materials obtained by comparing the intensity differences of a plurality of pairs of cameras with a threshold to make the identification more robust against acquisition noise.
[0088] According to an embodiment, the method of identifying a material in a scene comprises determining an extremum of a cost function obtained from the acquired images corresponding to two different polarization states.
[0089] FIG. 10 shows, in the form of a block diagram, an embodiment of a method of identifying a material in a scene.
[0090] Steps 50 and 52 are respectively identical to previously-described steps 40 and 42 .
[0091] At step 54 , processing and calculation device 27 determines, for each image point associated with a point of interest of the scene, a cost function Cost, for example, according to the following relation (2):
[0000] Cost=Σ k=1 N ∥I modeled k −I measured k ∥ (2)
[0000] where N is the number of images acquired with different polarization states, I measured k is the intensity measured at the considered image point, I modeled k is the theoretical intensity obtained by previously-described relation (1) and ∥x∥ is a norm, for example, the absolute value. As previously described, theoretical intensity I modeled k particularly depends on refraction index η of the material and on vector {right arrow over (N)} normal to the surface of the observed scene. The normal vector may be determined from the topology data provided by device 28 .
[0092] At step 56 , processing and calculation device 27 determines refraction index η for which cost function Cost is minimum.
[0093] Cost function Cost may further comprise a curve fitting term penalizing spatial transitions between optical indexes to increase the robustness of the identification against acquisition noise. In the case where function Cost is desired to be minimized, this curve fitting term may for example be a function increasing along with the homogeneity of the optical index in the vicinity of the point of interest. The curve fitting term may for example be deduced from the learning of a plurality of scenes where the material has been identified, for example, by an observer.
[0094] Specific embodiments of the present invention have been described. Various alterations and modifications will readily occur to those skilled in the art. Further, various embodiments with various variations have been described hereabove. It should be noted that those skilled in the art may combine various elements of these various embodiments and variations without showing any inventive step.
|
The invention relates to a method for identifying a material in a scene, including the following steps: lighting the scene ( 1 ); taking at least two simultaneous measurements of the light amplitude of the scene for separate polarisation states of the light using two measurement devices positioned in inclined directions above the normal of the scene; and deducing an identification of the material therefrom.
| 6
|
The invention relates to accessories for suspended ceiling grid construction and, in particular, to a seismic clip for stabilizing the grid members.
PRIOR ART
U.S. Pat. Nos. 5,046,294; 7,293,393; and 7,552,567 are examples of seismic clips used to limit movement of the ends of grid tee members at the perimeter of a suspended ceiling grid. There remains a need for an improved seismic clip that, while being economical, is both versatile and easy in installation and rugged in its construction. In particular, the clip should be capable of being both snapped over a grid tee and slipped onto the grid tee end to satisfy the installer's preference or need. The installation of an individual clip should not require a high assembly force or complicated manipulation since a typical job will require the assembly of a clip and tee to be repeated numerous times.
SUMMARY OF THE INVENTION
The invention provides a seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The disclosed clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled. More specifically, a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. As a related added benefit, the alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the seismic clip of the invention installed on the end of a grid tee and a wall angle;
FIG. 2 is a side elevational view of the seismic clip, grid tee and wall angle assembly;
FIG. 3 is a front elevational view of the seismic clip;
FIG. 4 is a right side elevational view of the seismic clip;
FIG. 5 is a left side elevational view of the seismic clip;
FIG. 6 is a top view of the seismic clip;
FIG. 7 is a side view of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, a seismic clip is used to tie or anchor a grid tee 11 to a wall angle 12 . The illustrated wall angle 12 is of a conventional construction being roll-formed sheet metal typically 10′ or 12′ long (or metric equivalent) and having perpendicular legs 13 of, normally, ⅞″ (or metric equivalent) width. The free edges of the legs 13 are folded back to form stiffening hems 14 . As is conventional, a vertical leg 13 of the wall angle 12 is attached to a wall 16 with screws, nails, staples, or the like at ceiling level.
The illustrated grid tee 11 can be a main tee or a cross tee, these terms being commonly understood in the industry. Relatively long main tees are assembled with shorter cross tees to make up a suspended grid for supporting rectangular ceiling panels. A conventional tee 11 has a lower flange 17 , a vertical stem or web 18 , and an upper reinforcing or stiffening hollow bulb 19 usually rectangular in form and nominally ¼″ (or metric equivalent) in width.
The seismic clip 10 is preferably a unitary stamping made of suitable metal such as 0.028″ hot dipped galvanized (H.D.G.) sheet steel. The geometry of the seismic clip 10 is described with reference to its installed orientation.
In plan view, shown in FIG. 6 , the clip 10 has a generally T-shaped configuration. The clip 10 is essentially symmetrical about a central vertical plane that when installed on a tee 11 , coincides with the plane of the web 18 of the tee. The clip 10 includes a pair of coplanar wings 21 that are perpendicular to and extend in opposite directions away from the central plane of symmetry. In an elevational view, shown in FIG. 3 , the wings 21 are generally rectangular. Tabs 22 that serve as hooks are lanced or stamped from the central areas of the wings 21 . The tabs 22 remain connected to the wings 21 at their upper regions 23 and lie in generally vertical planes, but preferably diverging from the plane of the wings at about 5 degrees, spaced slightly behind the plane of the wings. At the distal upper corners of the wings 21 are holes 24 for receiving screws or nails to fasten the clip 10 to a wall 16 . At the distal lower corners of the wings are similar holes 26 and, optionally concentric small circular embossments or standoffs that assist in keeping the clip in alignment with the planes of the wall 16 and ceiling by accounting for the thickness of the hems 14 .
A central section or saddle 31 of the clip 10 , forming the stem section of the T-shape of the clip seen in plan view, is proportioned to fit over the bulb 19 and web 18 of the end of a grid tee 11 . The saddle 31 is a double wall structure; the walls, designated 32 , 33 , are in parallel vertical planes. The walls 32 , 33 are spaced apart by an upper web 34 . The web 34 is preferably dimensioned to closely fit the walls 32 , 33 on the sides of the grid tee bulb 19 .
Below their bulb engaging areas, the saddle walls 32 , 33 are arranged to be spaced from the web 18 of the grid tee 11 . An elongated horizontal slot or opening 36 is formed in each saddle wall 32 , 33 so that the slots oppose one another. Above the slot 36 on each wall 32 , 33 are a pair of holes 37 . Adjacent a forward end or edge 38 of each wall, a tab 39 of trapezoidal shape is bent inwardly from a line or base 41 of attachment with the main body of the respective wall. In its free state, each tab 39 has an upper free or distal horizontal edge 42 configured, when assembled with a tee to extend beneath the bulb 19 and be spaced slightly from the tee web 18 .
On the right saddle wall 32 there is stamped or lanced a tab 43 . The tab 43 is angled inward and upward from a line or base 44 of attachment with the wall proper. The tab profile is that of a polygon with a forward edge 46 that angles rearwardly and upwardly from its base 44 , an upper horizontal free edge 47 , and a rearward edge 48 perpendicular to its base. Ideally, the tab 43 is similar to the leading tab 39 such that these tabs lie in a common plane and their respective bases 41 , 44 and upper edges 42 , 47 lie along common lines.
The clip 10 can, at the option of the installer, be assembled on the end of a grid tee 11 by either snapping it over the top of the bulb 19 or by sliding the tee and clip relative to one another in the longitudinal direction of the tee. A line 51 is embossed in the left saddle wall 33 to mark a distance of ¾″ from the plane of the wings 21 to be used as a gauge for the installer where a building code requires the grid tee to be installed not closer than this dimension from the vertical leg 13 of the wall angle 12 . The clip 10 is assembled on a wall angle by lowering it onto the vertical leg 13 with the hooks or tabs 22 behind the leg and the main clip body in front of the leg. This can be done before or after the clip is assembled with the tee.
The front or leading tabs 39 on the saddle walls 32 , 33 facilitate assembly of the clip onto the tee where the tee is inserted longitudinally into the clip. The leading edges of the tabs 39 guide the grid tee web 18 towards the center of the clip without impeding relative longitudinal motion. The free edges 42 of the tabs 39 are spaced only a limited distance greater than the thickness of the web 18 , so that the bulb 19 is roughly centered before the bulb engages the saddle 31 .
The lanced tab 43 serves to align the tee 11 and clip 10 so that the clip is restrained from tilting excessively upwardly. This is accomplished by the lanced tab 43 engaging the underside of the reinforcing bulb 19 with its upper edge 47 . The lanced tab 43 can be proportioned to allow some tilt between the clip 10 and tee 11 for ease of assembly and compatibility with various sized reinforcing bulbs. Such tilting is restricted so that where the clip 10 is positioned on the end of the grid tee 11 prior to positioning of the clip onto the wall angle 12 , the tilt is not severe enough to prevent the tabs or hooks 22 from contacting the wall and slipping behind the wall angle 12 . Reference is made to FIG. 7 where a prior art clip is seen to be free to tilt on a grid tee, pivoting about a point 56 of a tab. It will be seen in this figure that the lower edges of the clip wings can strike the upper edge of a wall angle 12 and prevent the hooks of such prior art design from slipping behind the vertical leg 13 of the wall angle 12 . The lanced tab 43 of the present invention can prevent this excessive tilting of the clip 10 thereby facilitating rapid assembly of the clip to the wall angle. Moreover, under seismic conditions, when a cross tee slips outwardly off the wall angle and gravity pulls down on the cross tee to prior art clip assembly, some damage may occur with loosening of the friction fit of the clip to the wall angle and tilting of the clip may occur. With the prior art clip under severe conditions excessive tilting may occur (similar to the showing in FIG. 7 ) and contribute to tile fall out. The lanced tab 43 of the invention wedges the bulb 19 between the lower side of the saddle 31 and the upper edge 47 of the tab 43 thus preventing this excessive tilting.
The clip 10 can be secured to the wall 16 after it is properly located on the wall angle with screws or nails in some or all of the wing holes 24 , 26 . Depending on the applicable building code, self-drilling screws can be driven into the reinforcing bulb 19 through the holes 37 that abut the sides of the bulb 19 to lock the clip 10 and tee 11 against relative movement. In other cases where limited movement between the clip 10 and tee 11 is desired, a self-drilling screw can be located at the center of the slot 36 and driven into the tee web 18 .
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
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A seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled whereby a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. The alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together.
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BACKGROUND OF THE INVENTION
This invention is directed to an apparatus for continuous hydraulic dredging. Customarily, a hydraulic dredge is swung from side-to-side in an arc during dredging operations and after digging through an arc, or through several arcs if the depth of the digging is greater than that removed by the cut of a single arc, the hydraulic dredge is moved forward using a digging spud and a walking spud which are located on opposite sides of the dredge stern. The movement from side-to-side during digging has been controlled by swing cables attached to swing anchors with the cables wound and unwound on winch drums. If the dredging is done in open water, the swing anchors are carried by boats to their positions and dropped into the water. If the dredging in done in a narrow channel, the swing anchors are located on land on opposite sides of the channel area being dredged.
In open water, the present method of moving the swing anchors requires the use of one or more anchor barges. When the dredge has completed digging in its arc, the anchor barge lifts one anchor and moves it forward the required distance which can possibly be 60, 70 or 80 feet. It then drops the anchor to the bottom of the cut. While this movement of the anchor is going on, the dredge has lowered its cutting ladder to the cut bottom so that it will hold itself in position while the setting of the anchor is tested. If the anchor which has been moved sets properly, then the anchor on the other side of the dredge must be moved to keep both anchors abreast of the dredge. If shore or land anchors are used, these must also be moved in the same manner. Under best dredging conditions, about 12% of available dredge time is spent in moving anchors. Under poor conditions, as much as 25% of the available dredge time can be spent relocating the anchors.
Another obstacle to continuous dredging is the necessity to move the dredge forward along its cutting path. With present types of dredges which use a walking spud and a digging spud, considerable time is wasted in lowering and lifting the walking and digging spuds when it is necessary to move the dredge to a new digging position.
Thus, an object of this invention is an apparatus for more efficiently conducting shallow dredging where the cutter head is moved through only a single cutting arc to reach its maximum digging depth.
Another object of this invention is an apparatus for advancing a hydraulic dredge without wasting any digging movements of the cutter head.
Another object of this invention is a dredging apparatus that does not require swing anchors.
Another object of this invention is a dredging apparatus that can dig efficiently in confined quarters.
Additional objects may be found in the following specification, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing of a prior art hydraulic dredge which is advanced by stepping it about a walking spud with several alternate positions of the hydraulic dredge shown in dashed and phantom lines;
FIG. 2 is a schematic view of apparatus of this invention for advancing a hydraulic dredge barge with several alternate positions of rotation of the hydraulic dredge barge shown in dashed and phantom lines;
FIG. 3 is a schematic depiction of the dredge barge of this invention being advanced during cutting with the dredge barge shown at opposite sides of its swath and shown in its advanced positions in dashed and phantom lines;
FIG. 4 is a enlarged partial side elevational view showing the pivotal mechanism for the dredge barge; and
FIG. 5 is a cross sectional view taken along line 5--5 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawings shows the prior art method of advancing a hydraulic dredge 11 after the completion of digging along an arcuate swath to a desired depth. In the example shown, the width of the dredging path or channel being dug is approximately 250 feet although it should be understood that it could be much wider or narrower. At the completion of a cutting arc, the hydraulic dredge 11 is at the left-hand side of the path as viewed in the drawings. The dredge has completed its cutting swath using its cutter head 13 which is mounted on a ladder 15 by pivoting about its digging spud 17 which is positioned material which is being removed is indicated at 19. The distance the cutter head is to be advanced into the bank which is the width of the swath 20 is 6 feet and the position of the bank after the swath is dug is indicated at 21. To advance the cutter head the width of the swath 20, it is necessary to advance the digging spud 17 a distance of six feet along the center line 23 of the dredging path. In order to move the digging spud 17 through the bank of material, it is necessary to swing the cutter head 13 and dredge 11 toward the center line 23 of the dredging pathabout its digging spud 17 while the cutter head is digging.
When the cutter head has been swung approximately 231/2° from the left side of the path to line 25 where the dredge is shown in dashed lines in the drawings, the walking spud 27 is lowered and embedded in the bottom of the channel in the position shown in FIG. 1. This new position is approximately 3 feet ahead of the original position of the digging spud 17. During the movement of the hydraulic dredge and cutter head from the far left position to the position of line 25 where the walking spud 27 is lowered and embedded, the cutter head has accomplished no dredging because it has not advanced into the bank 19. After the walking spud 27 is lowered and the digging spud 17 is raised, the hydraulic dredge 11 and its cutter head 13 are again rotated in a clockwise direction as shown in FIG. 1 past the center line 23 to line 29 where the dredge is shown in phantom line. This movement will position the hydraulic dredge and cutter head a clockwise distance of approximately 261/2° beyond the position of line 25. During this pivotal swing about the walking spud 27, the cutter head is digging at least partially into the bank 19 towards the new bank line. The digging spud 17 has now been advanced a forward distance of 6 feet from its original position and the digging spud 17 is lower and the walking spud 27 is raised. The cutter head will now be able to dig through the swath 20 all the way to the new bank 21.
The hydraulic dredge and its cutter head are again rotated in a clockwise direction as shown in FIG. 1 about the new position of digging spud 17 until the cutter head 13 reaches the end of its cutting arc, which is approximately another 261/2° beyond line 29. During this swing, the cutter head has removed the bank 19 through its full six foot swath 20. If the depth of the cut is such that the swath 20 has been dredged to its full depth, the counterclockwise rotation of the hydraulic dredge and its cutter head from the righthand side to the center line of the dredging path will be essentially wasted motion because no material will be removed from the bank during the first261/2° of movement (to line 29) and only approximately half of the swath 20 will be removed during the next261/2° of movement (to line 25). It will not be until the cutter head reaches line 25 that it will cut the full swath 20 of material. Thus, if only a single swing of the cutter head is necessary to remove the entire depth of the material being dredged, each side to side swing of the hydraulic dredge is only 50% efficient. The efficiency of such a dredge will increase if a number of swings are necessary to reach the full dredging depth before it is necessary to move the dredge forward into the bank. However, in any type of dredging where the dredge is stepped forward in the manner shown, there will be swings of the hydraulic dredge and cutter head where no digging takes place.
The apparatus of my invention is shown in FIGS. 2, 3, 4 and 5 of the drawings. In FIG. 2, the width of the dredge path, by way of example, is also 250 feet taken along center line 41. Hydraulic dredge barge 43 is equipped with a cutter head 45 mounted on a ladder 47 which is located at the forward end of the dredge. In my invention, the dredge barge 43 is equipped with a pivot sleeve 49 which is located on the center line of the dredge barge at the stern thereof and is fastened to the dredge barge. A large diameter bull ring 51 is also fastened to the hydraulic dredge barge and to the pivot sleeve concentrically therewith. A rod 55 which extends from a hydraulic cylinder 57 is pivotally connected to the pivot sleeve 49 by a universal type connection 59 consisting of a yoke 61 which receives the pivot sleeve 49. The yoke has diametrically projecting trunnions 63 which are journalled in openings (not shown) in a clevis 65 formed at the end of the rod 55. A bronze bearing 67 is located between the yoke 61 and the pivot sleeve 49 in the manner shown in FIGS. 4 and 5 of the drawings. An anchor spud 69 is supported on the hydraulic dredge barge 43 by upper and lower spud keepers 71 which permit it to move freely vertically through the pivot sleeve 49. The anchor spud may be raised and lowered relative to the pivot sleeve 49 in any conventional manner.
The hydralic cylinder 57 is mounted on a spud barge 73 which is positioned rearwardly of the stern of the hydraulic dredge barge 43. It should be understood and appreciated that the hydraulic cylinder 57 and rod 55 may be replaced by a rack and pinnion mechanism or the mechanical equivalent thereof which would also be mounted on the spud barge 73. The spud barge may be equipped with digging spuds such as spuds 75, 77, and 79 with one located on its port side and one on its starboard side and one on its center line just aft of the hydraulic cylinder 57. Of course it should be understood that other arrangements of the digging spuds may be provided.
The bull ring 51 is manipulated by means of cables 81 each of which is fastened at one end to the peripheral edge of the bull ring and has its other end wound around a power driven winch 83 mounted on the spud barge 73. The cables wind around sheaves 85 positioned on the barge for control of direction. A block and tackle (not shown) may be provided between each sheave and its winch to increase the mechanical advantage of the winches.
During dredging operations, the digging spuds 75, 77 and 79 are embedded in the bottom of the channel to hold the spud barge 73 in its proper position. The dredge barge 43 and its cutter head 45 are moved through digging arcs by winding and unwinding of the cables 81 around their power driven winches 83. The center of rotation of the dredge barge 43 during the cutting swings is about its pivot sleeve 49. When a cutting swath is completed, the dredge barge 43 is moved forward a distance equal to the depth of the new cut or swath by actuation of the hydraulic cylinder 57 which extends its rod 55 and thereby pushes the pivot sleeve 49 and the dredge barge 43, which is attached to it, away from the spud barge 73. When the rod 55 is fully extended relative to its hydraulic cylinder 57, it will then be necessary to relocate the spud barge 73 at the end of the final cutting swath. This is accomplished by dropping the anchor spud 69 when the cutter head reaches the end of its digging swing and embedding the anchor spud in the bottom of the channel. The digging spuds 75, 77 and 79 are then raised. The rod 55 is then retracted into the hydraulic cylinder 57 pulling the spud barge 73 up against the stern of the dredge barge 43. The digging spuds 75, 77 and 79 are again lowered and embedded into the bottom of the channel and the anchor spud 69 is raised. The hydraulic dredge barge is then again ready to resume its digging swings.
The efficiency of the apparatus of my invention is clearly shown in FIG. 3 of the drawings. The bank is indicated at 91. It is desired to advance the cutter head to cut a swath 93 having a width of 6 feet and to thereby established a new bank 95. After the swath 93 has been dug by a single swing of the cutter head 45, or multiple swings depending upon the depth of the cut, the hydraulic cylinder 57 is actuated to extend the rod 55 a distance equal to the width of the swath, in this example, a distance of 6 feet. The cutter head is returned in a counterclockwise direction as shown by the arrows digging a swath 97. When the cutter head reaches the end of the swath 97 it is advanced again by actuation of the hydraulic cylinder 57 which extends the rod 55 a distance which is equal to the width of the swath. The cutterhead is then swung clockwise to dig a new swath 99. Using the apparatus of my invention, a number of digging swaths can be made without relocating the spud barge 73. It is not necessary to manipulate any digging spuds until the rod 55 is extended to its full length. The use of swing anchors and the time consuming manipulation of them is eliminated.
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A dredging apparatus including a spud barge and a dredging barge. A hollow pivot sleeve is located at the stern of the dredging barge. A hydraulically extendable arm is mounted on the spud barge and is pivotally connected to the pivot sleeve. A large diameter bull ring is affixed to the pivot sleeve. A pair of cables connect to the bull ring and to a pair of power driven winches on the spud barge. The winding and unwinding of the cables around their winches swings the dredging barge about the pivot sleeve during dredging. An anchor spud extends through the hollow pivot sleeve to hold the dredging barge in fixed position when the spud barge is being relocated.
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REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 10/630,445, filed Jul. 30, 2003, now U.S. Pat. No. 7,273,497, which is a continuation of U.S. patent application Ser. No. 09/638,241, filed Aug. 14, 2000, now abandoned which is a continuation-in-part of International Patent Application No. PCT/US00/14708, filed May 30, 2000. The '241 application also claims priority from U.S. Provisional Patent Application Ser. No. 60/148,913, filed Aug. 13, 1999. The entire content of each application and patent is expressly incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention relates generally to the prosthetic appliances and, in particular, to devices for occluding intervertebral disc defects and instrumentation associated with introducing such devices.
BACKGROUND OF THE INVENTION
Several hundred thousand patients undergo disc operations each year. Approximately five percent of these patients will suffer recurrent disc herniation, which results from a void or defect which remains in the outer layer (annulus fibrosis) of the disc after surgery involving partial discectomy.
Reference is made to FIG. 1A , which illustrates a normal disc as viewed from the feet of a patient up toward the head. The nucleus pulposus 102 is entirely surrounded by the annulus fibrosis 104 in the case of healthy anatomy. Also shown in this cross section is the relative location of the nerves 106 . FIG. 1B illustrates the case of the herniated disc, wherein a portion of the nucleus pulposus has ruptured through a defect in the annulus fibrosis, resulting in a pinched nerve 110 . This results in pain and further complications, in many cases.
FIG. 1C illustrates the post-operative anatomy following partial discectomy, wherein a space 120 remains adjacent a hole or defect in the annulus fibrosis following removal of the disc material. The hole 122 acts as a pathway for additional material to protrude into the nerve, resulting in the recurrence of the herniation. Since thousands of patients each year require surgery to treat this condition, with substantial implications in terms of the cost of medical treatment and human suffering, any solution to this problem would welcomed by the medical community.
SUMMARY OF THE INVENTION
The subject invention resides in methods and apparatus for treating disc herniation, which may be defined as the escape of nucleus pulposus through a void or defect in the annulus fibrosis of a spinal disc situated between upper and lower vertebra. In addition to preventing the release of natural disc materials, the invention may also be used to retain bone graft for fusion, therapeutic and artificial disc replacement materials. The invention is particularly well suited to the minimization and prevention of recurrent disc herniation, in which case the defect is a hole or void which remains in the annulus fibrosis following disc operations involving partial discectomy.
In broad, general terms, to correct defects of this type, the invention provides a conformable device which assumes a first shape associated with insertion and a second shape or expanded shape to occlude the defect The device may take different forms according to the invention, including solidifying gels or other liquids or semi-liquids, patches sized to cover the defect, or plugs adapted to fill the defect.
The device is preferably collapsible into some form for the purposes of insertion, thereby minimizing the size of the requisite incision while avoiding delicate surrounding nerves. Such a configuration also permits the use of instrumentation to install the device, including, for example, a hollow tube and a push rod to expel the device or liquefied material out of the sheath for use in occluding the disc defect.
A device according to the invention may further include one or more anchors to assist in permanently affixing the device with respect to the defect. For example, in the embodiment of a mesh screen, the anchors may assume the form of peripheral hooks configured to engage with the vertebra on either side of the disc. The invention further contemplates a distracting tool used to force the anchors into the vertebra. Such a tool would preferably feature a distal head portion conformal to the expanded shape of the device, enabling the surgeon to exert force on the overall structure, thereby setting the anchors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross section of a human disc exhibiting normal anatomy;
FIG. 1B is a cross section used to illustrate a disc herniation;
FIG. 1C is a drawing of a disc following a partial discectomy, showing how a space or void remains in the annulus fibrosis;
FIG. 2 is a drawing which illustrates a preferred embodiment of the invention in the form of a flexible stent used to occlude a defect in the annulus fibrosis to minimize recurrent disc herniation;
FIG. 3A is a drawing of an applicator used to insert the flexible mesh stent embodiment of FIG. 2 ;
FIG. 3B shows the applicator of FIG. 3A with the stent partially expelled;
FIG. 3C illustrates a fully expanded shape assumed by the device of FIG. 2 following removal of the insertion tool;
FIG. 4A illustrates the addition of optional peripheral anchors around the stent in the FIG. 4 to assist in fixation;
FIG. 4B is an end view of the device of FIG. 4A including the peripheral anchors;
FIG. 5 is a side-view drawing of the device of FIGS. 4A and 4B anchored into upper and lower vertebra bounding the herniated disc;
FIG. 6A illustrates an optional distraction tool used to set the anchors of the device of FIGS. 4 and 5 into the vertebra;
FIG. 6B shows how the distracting tool would be inserted into the device to effectuate distraction;
FIG. 7A is a side-view drawing in partial cross-section illustrating the way in which notches may be made to adjoining vertebra to receive a device according to the invention;
FIG. 7B is a drawing of a tool which may be used to form the notches depicted in FIG. 7A ;
FIG. 7C illustrates the way in which a flexible body may be retained by the notches described with respect to FIGS. 7A and 7B ;
FIG. 8 illustrates an alternative orientation of a flexible body having a convex surface facing outwardly with respect to the wall of the disc being repaired;
FIG. 9A illustrates how the device according to the invention may be fixed with anchors that penetrate through the disc to be captured at the outer wall thereof;
FIG. 9B illustrates an alternative use of anchors which remain within the body of the disc material and do not penetrate its outer wall;
FIG. 9C illustrates an alternative method of fixation, wherein bone anchors are introduced into the vertebrae on either side of the disc in need of repair, as opposed to anchors deployed within or through the disc itself;
FIG. 10 illustrates an alternative device according to the invention in the form of a resilient plug;
FIG. 11A illustrates an alternative embodiment of the invention wherein a coiled wire is used to occlude a disc defect;
FIG. 11B is a side-view representation of the coiled wire of FIG. 11A ;
FIG. 11C illustrates how a wire with a coiled memory shape may be straightened and introduced using a plunger-type instrument;
FIG. 12 illustrates yet a different alternative embodiment of the invention wherein a material in liquid or gel form may be introduced into a defect, after which it hardens or solidifies to prevent further rupturing;
FIG. 13A illustrates yet a further alternative embodiment of the invention, in the form of a stent having a plurality of leaves;
FIG. 13B illustrates the alternative of FIG. 13A , wherein the leaves assume a second shape associated with defect occlusion, preferably through memory affect;
FIG. 14A illustrates an aspect of the invention wherein a conformable device is suspended within a gel or other resilient material for defect occlusion;
FIG. 14B is a side-view drawing of the embodiment of FIG. 14A ;
FIGS. 15A-15E are drawings which show various different alternative embodiments according to the invention wherein a patch is used inside and/or outside of a void in need of occlusion;
FIG. 16A is a top-view, cross-sectional drawing of a version of the invention utilizing posts or darts and sutures;
FIG. 16B is a side-view drawing of the embodiment of FIG. 16A ;
FIG. 17A shows how posts or darts may be criss-crossed to form a barrier;
FIG. 17B is a side-view drawing of the configuration of FIG. 17A ;
FIG. 18A is a side-view drawing of a barbed post that may be used for occlusion according to the invention;
FIG. 18B is an on-access view of the barbed post;
FIG. 18C illustrates how a single larger barbed post may be used for defect occlusion;
FIG. 18D illustrates how the barbed post of FIGS. 18A and 18B may be used in plural fashion to occlude a defect;
FIG. 19A is a drawing which shows how shaped pieces may be inserted to close off an opening;
FIG. 19B continues the progression of FIG. 19A , with the pieces being pulled together;
FIG. 19C illustrates the pieces of FIGS. 19A and 19B in a snapped-together configuration;
FIGS. 20A-20E are a progression of drawings which show how a shaped body may be held into place with one or more wires to block off a defect;
FIGS. 21A-21C illustrate how wires may be used in conjunction with snap-on beads to occlude a defect;
FIG. 22A illustrates the insertion of members adapted to receive a dam component;
FIG. 22B illustrates the dam of FIG. 22A locked into position;
FIG. 23A illustrates one form of defect block that accommodates compression and distraction;
FIG. 23B shows the device of FIG. 23A in compression;
FIG. 23C shows the device of FIG. 23A in distraction;
FIG. 23D illustrates the way in which the device of FIGS. 23A-23C , and other embodiments, may be tacked into place with respect to upper and lower vertebrae;
FIG. 24A is a drawing which shows an alternative device that adjusts for compression and distraction, in the form of a resilient dam,
FIG. 24B shows the resilient dam in compression;
FIG. 24C shows the resilient dam in distraction;
FIG. 25 illustrates a different configuration for the insertion of a resilient dam according to the invention;
FIG. 26 illustrates an alternative Z-shaped dam of resilient material;
FIG. 27A illustrates the use of interlocking fingers that permit compression and distraction while occluding a defect;
FIG. 27B is a side-view drawing in cross-section of the configuration of FIG. 27 ;
FIG. 28A illustrates an alternative interlocking finger configuration, and the way in which such members are preferably installed;
FIG. 28B shows how the first of the multiple members of FIG. 28A is installed;
FIG. 29A is a side-view drawing of a non-contained silicon blocking member prior to distraction;
FIG. 29B illustrates the way in which the device of FIG. 29A deforms upon distraction;
FIG. 30A is a side-view drawing in cross-section illustrating a contained silicon structure prior to distraction;
FIG. 30B illustrates how the contained silicon structure of FIG. 30A remains essentially the same in shape upon distraction;
FIG. 31A illustrates the use of threaded metal plug with particular applicability to bone graft retention;
FIG. 31B illustrates a rigid plug with ridges enabling it to be impacted into place;
FIG. 31C shows the use of asymmetric ridges to resist posterior migration;
FIG. 31D shows how teeth, screw threads or ridges on certain plug embodiments would extent at least partially into the adjacent vertebra for secure purchase; and
FIG. 32 illustrates bilateral plug positioning according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Having discussed the problems associated with post-operative partial discectomy with respect to FIG. 1A-1C , reference will now be made to FIG. 2 , which illustrates a preferred embodiment of the invention, wherein a device in the form of a stent 202 is used to occlude a defect 204 in a human disc, as shown. In this preferred embodiment, the device is composed of a flexible material, which may be cloth, polymeric or metallic. For reasons discussed below, a titanium mesh screen is preferred with respect to this embodiment of the invention.
A flexible device is also preferred because the surgeon is presented with a very small working area. The incision through the skin is typically on the order of 1 to 1.5 inches in length, and the space at the disc level is approximately 1 centimeter on the side. As a consequence, the inventive device and the tools associated with insertion and fixation described below must be sufficiently narrow to fit within these confines.
As shown in FIGS. 3A-3C , a flexible screen enables the device to be collapsed into an elongated form 302 , which, in turn, facilitates introduction into a sheath 304 associated with insertion. A push rod 306 may then be introduced into the other end of the sheath 304 , and either the sheath pulled backwardly or the push rod pushed forwardly, or both, resulting in the shape shown in FIG. 3C , now suitable for implantation.
To further assist in fixation with respect to the surrounding physiology, anchors 402 may be provided around a peripheral edge of the device, as shown in FIG. 4A . FIG. 4B shows an end view of the device of FIG. 4A , and FIG. 5 illustrates the device with anchors generally at 500 , being fixed relative to a defective disc 504 bounded by upper and lower vertebrae at 502 . It will be apparent to those of skill that each of the devices disclosed herein may be made in different sizes, having varying peripheral dimensions, for example, to match differently sized defects.
FIGS. 6A and 6B illustrate how a distracting tool 602 may be used to force the anchors into the vertebrae. That is, having introduced the device into the approximate area, the tool 602 , having a forward shape corresponding to that of the expanded mesh shape, may be introduced therein, as shown in FIG. 6B . With force being applied to the tool 602 , the anchors may be permanently set into the surrounding bone/tissue.
FIG. 7A illustrates an alternative approach to fixation, wherein one or more notches 700 may be made into the upper and lower vertebra, preferably through the use of an air-operated drill 704 shown in FIG. 7B , having a cutting wheel 702 adapted for such a purpose. FIG. 7C illustrates the way in which a flexible body 708 may be retained by the notches 700 described with respect to FIGS. 7A and 7B . FIG. 8 illustrates an alternative orientation of a flexible body having a convex surface facing outwardly with respect to the wall of the disc being repaired.
FIG. 9A illustrates a further alternative associated with fixation wherein anchors 902 which penetrate the outer wall of the disc 905 are used to hold a flexible repair device 900 in place as shown. FIG. 9B shows yet a further alternative fixation modality, wherein disc anchors 906 , which do not penetrate the outer wall of the disc, but, rather remain there within, are used to hold the device 904 in place.
FIG. 9C illustrates yet a further alternative mode of fixation, wherein anchors 908 are used to hold the device to upper and lower vertebra, as opposed to the anchors of FIGS. 9A and 9B , which are used with respect to the disc. Regardless of whether fixation takes place within the vertebra or within the disc, it will be noted that according to the preferred embodiment of the invention, both the device used to occlude the defect and the fixation means are sufficiently flexible that the defect remains occluded with movement of the spine, that is, with the patient leaning forwardly and backwardly which will tend to change the spacing between the upper and lower vertebra.
FIG. 10 illustrates yet a different embodiment of the invention wherein, as opposed to a piece of flexible material or mesh, a resilient plug 1002 is instead utilized to occlude the disc defect. As in the case of the flexible sheath-like embodiments described above, such plugs are preferably offered in different sizes to correlate with differently sized defects.
In terms of a preferred material, a device according to the invention will therefore remain sufficiently flexible during movement while being capable of exerting continuous outward forces and withstanding repetitive compression and distraction of millions of cycles. The device would, therefore, preferably be made of a material that has these characteristics, while, additionally being radio-opaque for X-ray imaging, without producing too many unwanted artifacts in magnetic resonance imaging. A wire mesh of titanium is therefore preferable, since this has the proper X-ray/MRI characteristics while exhibiting the requisite flexibility for the cyclic flexion and extension. With respect to the embodiment of FIG. 10 , a resilient, rubber-like material may be used to occlude the defect as shown in the drawing from a side-view perspective.
The invention is not limited in the sense that any conformable device may be used with a first shape permitting the device to be introduced into the defective area and a second shape wherein the device includes a defect. As shown in FIGS. 11A-11C , for example, a wire 1102 having a “memory effect” may be used, preferably having a final diameter which is larger than void 1104 . FIG. 11B shows the coil 1102 in cross-section between upper and lower vertebra. Preferably, this embodiment would use a metal wire that may be straightened, but retain the memory of its coiled shape. As such, the apparatus of FIG. 11C may be used to introduce the wire in straightened form 1108 with a plunger 1110 , such that as the wire exits at 1106 , it returns to its memorized state of a coil (or alternative second shape operative to include the defect).
As yet a different alternative mode of introduction, a material may be injected into the disc in liquid form, then allowed to hardened into a size sufficient to occlude the annular hole. As shown in FIG. 12 , material 1202 may be injected into the void of the disc space using a plunger 1204 inserted into a tube 1206 . Upon introduction in this manner, the liquid would then solidify, forming a resilient plug.
Various materials may be utilized for this purpose, including various polymers which are caused to solidify by various means, including thermal or optical activation, or chemical reaction as part of multi-part compounds. A preferred material with respect to this embodiment would be a hydrogel. Hydrogels may be placed into the disc in a dehydrated state, and, once inside the disc, they imbibe water. After hydration, hydrogels have the same biomechanical properties as a natural nucleus and, in addition, as the hydrogels swell, they become too large to extrude back through the annular window. U.S. Pat. Nos. 5,047,055 and 5,192,326 provide a listing of hydrogels, certain of which are applicable to this invention.
An elastomer may be used as an alternative to a hydrogel or other material. A number of elastomers may be suited to the invention, including a silicon elastomer, which comprises a cured dimethylsiloxane polymer and Hexsyn, having a composition of one-hexane with three to five percent methylhexaiene. A preformed elastomer may be inserted into the inclusion upon curing or, alternatively, as discussed with reference to FIG. 12 , may be injected into the disc space and liquid form. Chemicals may be added to accelerate curing, as discussed above, or, a hot or cold probe, or UV light may be introduced to facilitate or accelerate the curing process. Preferably, such materials would include a radio-opaque additive which would enable the physician to verify the position of the implant with an X-ray. Ideally, the radio-opaque additive would not change the mechanical properties of the gel or elastomer, and would ideally incorporate contrast throughout to enhance detail.
Now making to FIGS. 13 and 14 , FIGS. 13A and 13B illustrate an alternative type of stent having leaves or other appendages that may be folded into a compact state for insertion, FIG. 13A , and which expand, through memory affect, for example, to a state such as that shown in FIG. 13B . A stent such as this, as well as other devices disclosed herein such as the coil form of FIG. 11 , may be used in conjunction with a gel or other void-filling material as described above. As shown in FIG. 14A , a stent 1402 of the type shown with respect to FIG. 13B , may be introduced into the void, after which the remaining volume of the void may be filled with a material 1404 which solidifies into a resilient material. FIG. 14B is a side-view drawing of the embodiment of FIG. 14A . An expandable stent of this kind may be incorporated into the elastomer or other resilient material to help prevent migration of the prosthesis through the annular hole. In contrast to embodiments of the invention wherein a stent is used independently, in this particular embodiment, the stent would preferably not touch vertebra, since it would be surrounded entirely by the elastomer or other gel material.
FIGS. 15A-15E illustrate various alternative embodiments according to the invention wherein a patch material is used inside, outside, or partially inside and outside of a defect to be blocked. FIG. 15A illustrates a flat patch attached onto the outside of the disc. FIG. 15B illustrates a patch attached on the outside but wherein a central portion extends inwardly into the void. FIG. 15C illustrates a patch disposed within the disc to block the defect. FIG. 15D illustrates how a patch may be anchored to the bone above and below the disc, and FIG. 15E illustrates how the patch may be anchored to the disc itself. The patch material be a fiber, including natural materials, whether human, non-human or synthetic; an elastomer; plastic; or metal. If a fiber material is used, it may be selected so as to promote tissue in-growth. Growth of a patient's tissue into the material would assure a more permanent closure of the annular window. The patch may be attached within appropriate means, including stitches, staples, glue, screws or other special anchors.
In addition to the use of patches attached with sutures, staples or other materials, the annular defect may be closed with staples or other devices which attach to the annulus without the need for patch material. For example, as shown in FIG. 16A , darts 1602 may be inserted through the wall of the annulus 1604 , then linked with sutures 1606 , preferably in woven or criss-crossed fashion, as shown in FIG. 16B . As an alternative, appropriately shaped darts 1702 may be criss-crossed or otherwise interlocked to the close the annular hole, as shown in the top-view cross-section drawing of FIG. 17A or a side-view of FIG. 17B .
The use of flexible stents as described elsewhere herein may take on other forms, as shown in FIGS. 18A-18D . The device of FIG. 18A , for example, preferably includes a body 1802 , preferably including a blunt anterior end to prevent penetration of the anterior annulus, and outer spikes 1806 , preferably having different lengths, as best seen in the on-axis view of FIG. 18B . Such a stent configuration may provide more areas of contact with the vertebral end plates, thereby decreasing the chances of stent extrusion. As shown in FIG. 18C , the longer spikes 1806 are configured to bend during insertion, thereby preventing posterior extrusion. The shorter spikes, 1806 ′, are sized so as not to engage the vertebrae, and therefore may be made thicker to prevent deflection by disc material. As an option, the shorter spikes 1806 ′ may also be angled in the opposite direction as compared to the longer spikes 1806 to resist migration of the disc material. As yet a further option, the longer spikes may vary in length on the same stent so as to be conformal to the vertebral end plate concavity. As shown in FIG. 18D , multiple spike stents of this kind may be inserted so as to interlock with one another, thereby preventing migration of the group.
As shown in FIGS. 19A-19C , shapes other than spiked stents may be used in interlocking fashion. In FIG. 19A , a first piece 1902 is inserted having a removable handle 1904 , after which pieces 1902 ′ and 1902 ″ are inserted, each having their own removable handles, as shown. In FIG. 19B , the handles are pulled, so as to bring the pieces together, and in FIG. 19C , the handles are removed, and the pieces are either snapped together or, through the use of suitable material, sutured into place. FIGS. 20A-20E illustrate a different configuration of this kind, wherein a body 2002 having anchor or wire-receiving apertures 2004 is inserted into the annular hole, as shown in FIG. 20B , at which time a wire 2006 is inserted through the body 2002 as shown in FIG. 20C . As shown in FIG. 20D , the wire is installed sufficient to lock one portion of the body into place, and this is followed with a wire on the opposite side, thereby holding the body 2002 in a stabilized manner. It will be appreciated that although multiple wires or anchors are used in this configuration, bodies configured to receive more or fewer wires or anchors are also anticipated by this basic idea.
FIGS. 21A-21C illustrate a different alternative, wherein wires 2102 each having a stop 2104 are first inserted through the annular window, after which blocking beads having snap-in side configurations are journaled onto the wire across the annular hole, as shown in FIG. 21B . FIG. 21C illustrates how, having locked multiple beads onto the wire, the defect is affectively occluded. FIGS. 22A and 22B illustrate the use of a removable dam component. As shown in FIG. 22A , bodies 2202 , each having removable handles 2204 , are first inserted on the side portions of the defect, each member 2202 including slots, grooves or apertures 2206 , configured to receive a dam 2210 , which may be made of a rigid or pliable material, depending upon vertebral position, the size of the defect, and other factors. FIG. 22B illustrates the dam 2210 locked in position.
Certain of the following embodiments illustrate how the invention permits the use of a flexible device which allows movement between the vertebrae yet blocks extrusion of nucleus through an annular hole or defect. In FIG. 23A , for example, a flexible element 2302 is tacked into position on the upper vertebrae, as perhaps best seen in FIG. 23D , though it should be apparent that a fixation to the lower vertebrae may also be used. FIG. 23B illustrates how, once the member 2302 is fastened in place, it may flex under compression, but return to a more elongated shape in distraction, as shown in FIG. 23C . The blocking element 2302 may be made from various materials, including shape-memory materials, so long as it performs the function as described herein. FIG. 24A illustrates a different configuration, which is tacked to both the upper and lower vertebrae, and FIGS. 24B and 24C show how the device performs in compression and distraction, respectively. Since devices attached to both the upper and lower vertebrae need not automatically assume a memorized shape, alternative materials may preferably be used, including biocompatible rubbers and other pliable membranes. It is important that the flexible member not be too redundant or stretched so as to compress the nerve, as shown in FIG. 25 . FIG. 26 illustrates an alternative Z-shaped installation configuration.
As an alternative to inherently flexible materials which occlude a defect while accommodating compression and distraction, interleaving members may alternatively be used, as shown in FIGS. 27-28 . FIG. 27A is a view from an oblique perspective, showing how upper and lower plate 2702 and 2704 of any suitable shape, may be held together with springs 2706 , or other resilient material, between which there is supported interleaving tines 2708 . As better seen in FIG. 27B , the springs 2706 allow the upper and lower plates 2702 and 2704 to move toward and away from one another, but at all times, tines 2708 remain interleaving, thereby serving to block a defect.
FIGS. 28A and 28B illustrate the way in which interleaving members or tines are preferably inserted directly to vertebrae. Since each member overlaps with the next, such tines are preferably installed from front to back (or back to front, as the case may be), utilizing a tool such as 2810 , as shown in FIG. 28B . The instrument 2810 forces each tack into one vertebrae at a time by distracting against the other vertebrae, thereby applying pressure as the jaws are forced apart, driving the tack into the appropriate vertebrae. The tack may be held into place on the instrument by a friction fit, and may include a barbed end so as not to pull out following insertion.
As a further alternative configuration, a collapsed bag may be placed into the disc space, then filled with a gas, liquid or gel once in position. The bag may be empty, or may contain a stent or expanding shape to assist with formation. In the case of a gel, silicon may be introduced so as to polymerized or solidify. As shown in FIGS. 29A and 29B , the use of a non-contained silicon vessel may be used, but, under distraction, may remain in contact with the vertebrae, thereby increasing the likelihood of a reaction to silicone. The invention therefore preferably utilizes a contain structure in the case of a silicon filler, as shown in FIG. 30A , such that, upon distraction, the vessel remains essentially the same shape, thereby minimizing vertebral contact.
It is noted that, depending upon the configuration, that the invention may make use of a bioabsorbable materials, that is, materials which dissolve in the body after a predetermined period of time. For example, if darts such as those shown in FIGS. 16 and 17 are used, they may bioabsorb following sufficient time for the in-growth of recipient tissue sufficient to occlude the defect independently. Any of the other configurations described herein which might not require certain components in time may also take advantage of bioabsorbable materials. Furthermore, although the invention has been described in relation to preventing the release of natural disc materials, the invention may also be used to retain bone graft for fusion; therapeutic materials including cultured disc cells, glycosaminoglycans, and so forth; and artificial disc replacement materials.
Disc fusions are generally performed for degenerative disc disease, spondylolysis (a stress fracture through the vertebra), spondylolisthesis (slippage of one vertebra on another), arthritis of the facet joints, spinal fractures, spinal tumors, recurrent disc herniations, and spinal instability. The procedure attempts to eliminate motion between vertebra to decrease a patient's pain and/or prevent future problems at the intervertebral level.
Devices such as spinal cages are generally used in conjunction with such procedures to maintain the separation between the vertebrae until fusion occurs. Some surgeons believe that cages are not necessary to maintain the separation, and instead use pedicle screws or hooks and rods to perform this function. Whether or not a cage is used, bone graft is generally introduced through a hole formed in the disc space to achieve an interbody fusion.
Unfortunately, bone material placed into the disc space can extrude through the hole used for insertion. Bone graft extruded through a hole in the posterior portion of the disc may cause nerve root impingement. The procedure to fuse vertebra across the disc space from a posterior approach is known as a PLIF (posterior lumbar interbody fusion). Bone can also be placed into the disc space from an anterior approach ALIF (anterior lumbar interbody fusion). Extruded bone from an anterior approach would not lead to nerve impingement but could decrease the likelihood of a successful fusion by decreasing the volume of bone graft.
The present invention may be used to prevent the loss of the bone graft material associated with fusion techniques, whether or not a cage is used. In this particular regard, however, some of the devices disclosed herein may be more suitable than others. Generally speaking, since the goal is not to preserve disc function and motion, the stent, plug, and patch embodiments may be more appropriate. Although the plug embodiment would be a good choice when there is ample room in the spinal canal to allow insertion, the expandable stent design would be beneficial when plug insertion risks nerve injury. Conversely, since the goal is to maximize the amount of bone inserted into the disc space, the embodiments using hydrogels and elastomers might not be optimum, since such materials may occupy too much space in some circumstances.
The preferred choice of materials may also be changed since motion is not being maintained. Materials and designs with shape memory may be beneficial. As another example, the polymer plug embodiment may changed to a metal such as titanium. A metal plug may be fabricated with threads and screwed into place, as shown in FIG. 31A , or the device may feature ridges and be impacted into place ( FIG. 31B ). As shown in FIG. 31C , the ridges may also be asymmetric to resist posterior migration. In all cases, the teeth, screw threads or ridges would extent at least partially into the adjacent vertebra for secure purchase, as depicted in FIG. 31D . Such plugs may also be positioned bilaterally, that is, with two per level, as shown in FIG. 32 .
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Methods and apparatus for treating defects in the annulus fibrosis are described. The methods include providing first and second elongate fastening members, each having a first end and an anchor on the first end that is substantially transverse when deployed. The first end of the first and second elongate fastening members are positioned distal of the outer layer and at least one inner layer of the annulus fibrosis. The defect is then closed by interlocking the first and second elongate fastening members. Alternatively, second ends of the elongate fastening members may be linked, resulting in reducing the size of the opening of the defect. Devices having first and second elongate fastening members, each having a first end, a second end, and an anchor on the first end that is substantially transverse when deployed; and a connector that links the first and second elongate fastening members are also described.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application No. 60/657,998, filed on Mar. 2, 2005, the entire contents of which are incorporated herein by reference.
BACKGROUND
This invention relates to flyer bows. Flyer bows for use on twisting machines are well known in the art. Twisting machines with flyer bows can be used to make twisted cables for a wide variety of uses. Flyer bows can be used with pairing, tripling, quadding, bunching and twisted machines for wires. A typical flyer bow is generally rectangular in cross section. Wires to be twisted pass longitudinally along the inside surface of the flyer bow and are guided along the surface through ceramic or metal wire guides. A groove or recessed channel in the inside surface of the flyer bow is often incorporated into the design of the flyer bow in order to nest the wires to be twisted close to the surface of the flyer bow. This configuration reduces drag on the wires due to wind that sweeps transversely across the flyer bow during use. Flyer bows with airfoil shapes have been successfully used to increase speed of the winding machines with the benefits of minimum power draw and reduced operational noise. However, the airfoil does little, if anything, to minimize the effect of drag on the exposed wires. Furthermore, the exposed wire guides create additional drag on the flyer bow as it rotates.
An existing flyer bow is described in U.S. Pat. No. 6,223,513 B1, issued to Post et al. and assigned to Kamatics Corporation, the entire contents of which are incorporated herein by reference. U.S. Pat. No. 6,223,513 B1 discloses a flyer bow with an integral enclosed wire guide. This design reduces drag by incorporating the wire guide within the flyer bow.
BRIEF DESCRIPTION OF THE INVENTION (SUMMARY)
Disclosed here in is a flyer bow for use in a wire-twisting machine including a body with an airfoil shaped cross section, a recessed channel within the body and a series of wire guide inserts retained within the recessed channel.
Further disclosed herein is a wire guide insert including a tubular body having an exterior non-circular shape corresponding to a similar non-circular shape of a channel and an exhaust opening in the wire guide inserts.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a front plan view of a conventional flyer bow.
FIG. 2 is a cross section view of the flyer bow of FIG. 1 taken at arrows 2 — 2 .
FIG. 3 is a front plan view of a flyer bow depicting one embodiment of the present invention.
FIG. 4 is a cross section view of the flyer bow of FIG. 3 taken at arrows 4 — 4 .
FIG. 5 is a cross section view of an alternate embodiment of the invention showing the wire guide insert in the hexagonal channel.
FIG. 6 is a bottom plan view of a hexagonal wire guide insert.
FIG. 7 is a front plan view of the wire guide insert of FIG. 6 .
FIG. 8 is a section view of the wire guide insert of FIG. 7 taken at arrows 8 — 8 .
FIG. 9 is an alternate embodiment with corrugated bumps on the inside diameter of the wire guide insert.
FIG. 10A illustrates the shape of a rotating flyer bow in embodiments of the invention.
FIG. 10B illustrates the shape of a rotating, conventional flyer bow.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , a conventional flyer bow 10 includes a body 20 , the wire guides 30 and the recessed channel 21 . The recessed channel 21 and the airfoil shape of the body 20 illustrate conventional techniques incorporated to minimize the drag of the flyer bow 10 during operation of the twisting machine. Protrusion of the wire guides 30 outside the airfoil shape of the body 20 and into the air stream result in higher drag, less efficiency and more power consumption.
Referring to FIGS. 3 and 4 , in one embodiment of the invention the flyer bow 70 includes an aerodynamic airfoil shaped body 80 with a recessed hexagonal shaped channel 81 , without the use of wire guides that protrude into the air stream resulting in higher aerodynamic losses. In tests conducted on wire twisting machines, embodiments of the invention consumed 12.3% less power than a conventional steel body with exposed wire guides and 4.6% less power than a conventional composite airfoil shaped body with exposed wire guides. In addition to the extra power required to run the twisting machines (electric power costs) there was more noise.
Referring to FIG. 5 , an alternate embodiment illustrates the use of wire guide inserts 90 , that are retained completely within the airfoil shape of the body 80 in channel 81 . The hexagonal shape of the insert 90 matches that of channel 81 to prevent rotation of the insert 90 within the channel 81 , which maintains alignment of the insert opening 91 , as best depicted in FIGS. 7 and 8 , with the channel opening 82 . Both the insert opening 91 and the channel opening 82 allow for egress of dust that is created by the wire 50 passing through the wire guide inserts 90 during operation of the twisting machine. This feature provides for a self-cleaning design and provides for a maintenance free feature so that the twisting machine does not have to be shut down to clear the dust that could clog the channel in the bow.
Though a hexagonal shaped insert 90 and hexagonal channel 81 are depicted in this embodiment in FIG. 5 , it should be understood that any non-circular shaped cross section that provides for anti-rotation of the insert 90 within the channel 81 (such as an ellipse, square, pentagon, octagon, etc.) could adequately serve this function without deviating from the present invention.
The wire guide inserts 90 shown in FIGS. 6 through 8 are assembled into channel 81 from either end of the body 80 in an end-to-end fashion. The wire guide inserts 90 abut each other along the channel 81 to maintain the position of the wire guide inserts 90 within the channel 81 . The wire guide inserts 90 at the ends of the body 80 are secured in position by a retainer (not shown).
The wire guide inserts 90 can be constructed of any material that has a hard, wear resistant surface, to resist wear by the wire that passes through them. A partial material listing includes: steel, or steel that has had a surface plating or coating applied to it to increase the hardness such as titanium carbo-nitride (TiCN), titanium-nitride (TiN), electrolytic or electroless nickel plating, chrome plating, ceramic coatings, etc. The insert can also be made of nickel based alloys such as inconel, ceramic materials, plastic composites, etc.
The wire guide inserts 100 as shown in FIG. 9 , can also be shaped with an undulating interior surface 101 , that reduces the contact area with the wire 50 that passes through the inserts 100 , thereby decreasing the frictional forces and resulting drag on the wire.
The body 80 , as shown in FIG. 5 , can be constructed from composite material including but not limited to carbon fiber epoxy, fiberglass epoxy, aramid fiber epoxy, or a combination of two or three of the materials mentioned. The body 80 may be reinforced with a carbon fiber 85 material using a braided structure for the carbon fibers 85 . The use of a braided fiber 85 construction is also unique as this type of construction increases the strength of the body 80 and allows the body 80 to have increased damage tolerance and increased resistance to fractures due to impacts from wire 50 strikes. The wire 50 that passes through the wire twisting machine will at times break and the broken wire 50 can impact the body 80 which is rotating at a high speed in the machine. The braided fiber 85 construction is more resilient to wire 50 strikes and the braided fiber 85 construction works to arrest any cracks that may be initiated due to a wire 50 strike resulting in a longer body 80 life.
Referring again to FIG. 5 , the body 80 of the bow may also have hollow sections 86 to decrease the weight while increasing the stiffness and give it an I-beam geometric shape. The reduction of weight of the body 80 reduces the centrifugal pull on the airfoil body 80 attachment ends. The hollow sections 86 can also be filled with foam 87 to further increase stiffness of the body 80 without adding significantly to the weight of the body 80 . The thicker section that is provided by the use of an airfoil section to contain the wire guide inserts 90 and the wire 50 internally, also produces a stiffer airfoil cross section. This stiffer cross section enables the body to keep its as manufactured curved shape 120 even under the high centrifugal loads that are imposed on the body when it is spinning in the wire twisting machine as is depicted in FIG. 10A . Conventional designs with thinner cross sections tend to produce an irregular shape 130 and tend to flatten at the apex of the bow while rotating as shown in FIG. 10B . The result of the irregular shape 130 is that the wire makes greater contact with the wire guides and degrades the quality of the wire due to the abrasion by the greater contact area and force.
While preferred embodiments have been shown and described, various modifications and substitutions maybe made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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Disclosed herein is a flyer bow for use in a wire-twisting machine including a body with an airfoil shaped cross section, a recessed channel within the body and a series of wire guide inserts retained within the recessed channel. Further disclosed herein is a wire guide insert including a tubular body having an exterior non-circular shape corresponding to a similar non-circular shape of a channel and an exhaust opening in the wire guide inserts.
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BACKGROUND
[0001] Hydrocarbon fluids such as oil and gas are found in subterranean portions of geological formations or reservoirs. Wells are drilled into these formations for extracting the hydrocarbon fluids. Wells may be completed in a variety of ways including open hole and cased hole configurations. The processes involved in completing well bores and producing hydrocarbons from them often require isolation of one or more zones from another. For example, the well bore may pass through multiple production zones. In these applications, it may be desireable to isolate the non-productive regions located between the production zones. In particular, the annular region on a well bore disposed between the well bore wall (or casing) and the string may need to be isolated.
[0002] A variety of packers have been developed to isolate such regions. For example, mechanical, inflatable, chemical and pneumatic packers may be used. Such packers may respond to hydraulic pressure by expanding to fill the annulus. Swell rubber packers have been used that rely on an elastomeric material such as rubber and its tendancy to swell in presence of hydrocarbons. Such packers have been disclosed in U.S. Pat. Publication No. 2007/0151723 by Freyer. These packers expand to fill an annulus when comes in contact with the wellbore fluids and have the advantage of not relying on separate actuation means or moving parts.
[0003] When the elastomer comprising the swell packer expands, the mechanical properties of the elastomer deteriorate and the packer weakens. As a result, the elastomer becomes prone to failure when exposed to high differential pressures. This may result in extrusion of the elastomer along the pressure gradient and the loss of the annular seal.
[0004] Accordingly, some packers have been provided with rigid, solid collars or rings placed at either end of the swell packer. Such devices may not reliably prevent extrusion as the variable diameter of a well bore may leave room between the collar and the wellbore wall that could allow for a portion of the elastomer to be extruded into the anular region above or below the packer. Also, such solid collars limit the ability to deploy intelligent completions devices such as fiber optic lines, wirelines, communications devices, sensors, and other such devices as the solid collar does not allow for deployment of such devices through the annular region.
[0005] Accordingly, there is a need for an anti-extrusion device for a swell packer that may reliably fill the annular region and prevent or limit extrusion under relatively high differrential pressures. There is also a need for an anti extrusion device that is capable of use while deploying intelligent well completions devices in conjunction with a swell packer.
SUMMARY
[0006] Some embodiments relate to a system for use in a wellbore. The system may comprise a tube, a swell packer surrounding a portion of the tube, a first pair of plates coupled to an outer surface of the tube and positioned at a first end of the swell packer, each of the first pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals, wherein at least one of the slots of one of the first pair of plates overlaps with at least one of the petals of the second of the first pair of plates, and a second pair of plates coupled to the outer surface of the tube and positioned at a second end of the swell packer, each of the second pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals wherein at least one of the slots of one of the second pair of plates overlaps with at least one of the petals of the second of the second pair of plates.
[0007] Other embodiments relate to a system for use in a wellbore comprising a tube, a swell packer surrounding a portion of the tube, a first pair of plates coupled to an outer surface of the tube and positioned at a first end of the swell packer, each of the first pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals, wherein at least one of the slots of one of the first pair of plates overlaps with at least one of the petals of the second of the first pair of plates, and a second pair of plates coupled to the outer surface of the tube and positioned at a second end of the swell packer, each of the second pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals wherein at least one of the slots of one of the second pair of plates overlaps with at least one of the petals of the second of the second pair of plates. A passage through the first pair of plates, the second pair of plates, and the swell packer may be provided, and a second tube disposed within the channel.
[0008] Yet other embodiments relate to a system for use in a well bore comprising a tube, and a swell packer surrounding a portion of the tube. A first anti-extrusion device may be disposed at a first end of the swell packer and a second anti-extrusion device disposed at a second end of the swell packer. A passage through the first anti-extrusion device, the swell packer and the second anti extrusion device may be provided and a communication line disposed within the passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross sectional view of a system for use in a wellbore.
[0010] FIG. 2 is an end view of plates for use in the wellbore system of FIG. 1 taken along line 2 - 2 .
[0011] FIG. 3 is a cross sectional view of a system for use in a wellbore.
[0012] FIG. 4 is an end view of plates for use in the wellbore system of FIG. 3 taken along line 4 - 4 .
[0013] FIG. 5 is a cross sectional view of a system for use in a wellbore.
[0014] FIG. 6 is an elevation view of plates for use in the wellbore system of FIG. 5 taken along line 6 - 6
[0015] FIG. 7 is a cross sectional view of a system for use in a wellbore.
[0016] FIG. 8 is a cross sectional view of a system for use in a wellbore.
[0017] FIG. 9 is an elevation view of plates for use in the wellbore system of FIG. 8 taken along line 9 - 9 .
[0018] FIG. 10 is a cross sectional view of a system for use in a wellbore.
[0019] FIG. 11 is an elevation view of plates for use in the wellbore system of FIG. 10 taken along line 11 - 11 .
DETAILED DESCRIPTION
[0020] Referring to FIGS. 1 and 2 , a system 10 comprises a string 12 , shown as a production tube, swell packer 14 , and plates 16 . Swell packer 14 may comprise an elastomeric material that will expand in the presence of hydrocarbons or specific fluid. Swell packer 14 is positioned along an outer surface of string 12 such that packer 14 is disposed between string 12 and a wall 18 to provide a flow region 20 and an annular region 22 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 14 to expand and seal the annular region. Wall 18 may be a cement or other casing or may be the wall of an open hole. Coupler 24 may be used in conjunction with plates 16 . Coupler 24 extends through a first set of plates, through the swell packer 14 and through the second set of plates. The coupler may be a rod and may be secured at a first end with a head 26 and at a second end with a fastener 28 . Coupler 24 may be tensioned to resist movement of plates 16 along string 12 as packer 14 swells.
[0021] FIG. 2 shows two types of plates 16 a and 16 b that may be used to provide an extrusion barrier. Each of plates 16 a and 16 b include a plurality of petals 30 . Each petal is positioned adjacent two slots 32 . The petals are angled towards swell packer 14 from a deflection point 34 . Seals 36 may be provided in apertures 38 to prevent extrusion between plates 16 and couplers 24 . The position of apertures 38 relative to petals 30 may be varied such that the petals of plate 16 a overlap the slots 32 of plate 16 b and vice versa. The overlapping petals prevent extrusion of the elastomeric material through the slots 32 . When positioned down hole, swell packer 14 will contact hydrocarbons and expand to fill the annular region. Unlike rigid collars that have been used to bound the lateral expansion of the packer, petals 30 of plates 16 may be deflected outward towards wall 18 . This allows provides for a tight seal of the annular region and further restricts the extrusion of the elatomeric material. At least one of plates 16 a and one of plates 16 b are used at each end of swell packer 14 . In other embodiments additional plates may be used depending on the pressures that will be encountered.
[0022] Referring to FIGS. 3 and 4 , a system 110 comprises a string 112 , shown as a production tube, swell packer 114 , and plates 116 . Swell packer 114 may comprise an elastomeric material that will expand in the presence of hydrocarbons. Swell packer 114 is positioned along an outer surface of string 112 such that packer 114 is disposed between string 112 and a wall 118 to provide a flow region 120 and an annular region 122 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 114 to expand and seal the annular region. Wall 118 may be a cement or other casing or may be the wall of an open hole. Coupler 124 may be used in conjunction with plates 116 . Coupler 124 extends through a first set of plates, through the swell packer 114 and through the second set of plates. The coupler may be a rod and may be secured at a first end with a head 126 and at a second end with a fastener 128 . Coupler 124 may be tensioned to resist movement of plates 116 along string 112 as packer 114 swells.
[0023] FIG. 4 shows two types of plates 116 a and 116 b that may be used to provide an extrusion barrier. Each of plates 116 a and 116 b include a plurality of petals 130 . Each petal is positioned adjacent two slots 132 . The petals are angled towards swell packer 114 from a deflection point 134 . Seals 136 may be provided in apertures 138 to prevent extrusion between plates 116 and couplers 124 . The position of apertures 138 relative to petals 130 may be varied such that the petals of plate 116 a overlap the slots 132 of plate 116 b and vice versa. The overlapping petals prevent extrusion of the elastomeric material through the slots 132 . When positioned down hole, swell packer 114 will contact hydrocarbons and expand to fill the annular region. Unlike rigid collars that have been used to bound the lateral expansion of the packer, petals 130 of plates 16 may be deflected outward towards wall 118 . This allows provides for a tight seal of the annular region and further restricts the extrusion of the elatomeric material.
[0024] In each of plates 16 , a slot 140 is provided. In each of plates 16 a , a slot 140 is positioned where on e of slots 132 would normally be positioned. In some embodiments slot 140 a may be the same size and shape as slots 130 . In other embodiments, as shown, slot 140 a may be larger than one of slots 130 . In each of plates 16 b , slot 140 b may be centered on a petal 130 relative to the arc of the petal, such that slots 140 a and 140 line up to provide a passage 142 through the anti extrusion device. Tube 144 may be run through passage 142 to accommodate a communication line or other device. Cover 146 may be used to hold tube 144 in place relative to plate 16 . Cover 146 may comprise the same swelling elastomeric material as packer 114 thus providing a passage along the whole length of swell packer 114 . Alternatively, apertures may be provided in plates 16 a and 16 b to provide a passage.
[0025] Referring to FIGS. 5 and 6 , a system 210 comprises a string 212 , shown as a production tube, swell packer 214 , and plates 216 . Swell packer 214 may comprise an elastomeric material that will expand in the presence of hydrocarbons. Swell packer 214 is positioned along an outer surface of string 212 such that packer 14 is disposed between string 212 and a wall 218 to provide a flow region 220 and an annular region 222 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 214 to expand and seal the annular region. Wall 218 may be a cement or other casing or may be the wall of an open hole. Plates 216 may be positioned between swell packer 214 and couplers 248 . Couplers 248 are configured to resist lateral movement of pates 216 relative to mandrel 212 a . Couplers 248 may be threaded to mandrel 212 a and tubing 212 . FIG. 6 shows plate 216 that may be used to provide an extrusion barrier. Each of plates 216 include a plurality of petals 230 . Each petal is positioned adjacent two slots 232 . The petals are angled towards swell packer 214 from a deflection point 234 . Alternating plates 216 may be positioned such that the petals 230 of one plate 216 overlap with the slots 232 of the adjacent plate 216 . The overlapping petals prevent extrusion of the elastomeric material through the slots 232 . When positioned down hole, swell packer 214 will contact hydrocarbons and expand to fill the annular region. Unlike rigid collars that have been used to bound the lateral expansion of the packer, petals 230 of plates 216 may be deflected outward towards wall 218 . Alternately, a passageway and tube can be provided with same arrangement as shown in FIG. 3 .
[0026] Referring to FIG. 7 , a system 310 comprises a string 312 , shown as a production tube, swell packer 314 , and plates 316 . Swell packer 314 may comprise an elastomeric material that will expand in the presence of hydrocarbons. Swell packer 314 is positioned along an outer surface of string 312 such that packer 314 is disposed between string 312 and a wall 318 to provide a flow region 320 and an annular region 322 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 314 to expand and seal the annular region. Wall 318 may be a cement or other casing or may be the wall of an open hole. Plates 316 may be positioned between swell packer 314 and couplers 348 . Couplers 348 are configured to resist lateral movement of pates 316 relative to mandrel 312 a . Couplers 350 may be threaded to mandrel 312 a and tubing 312 . One or more of plates 316 positioned closes to swell packer 314 may be provided with extensions 356 which extend roughly parallel to tube 312 and extend from a deflection point 358 . Extensions 356 may serve to further reduce extrusion of the elastomer material past plates 316 .
[0027] Referring to FIGS. 8 and 9 , a system 410 comprises a string 412 , shown as a production tube, swell packer 414 , and plates 416 . Swell packer 414 may comprise an elastomeric material that will expand in the presence of hydrocarbons. Swell packer 414 is positioned along an outer surface of string 412 such that packer 414 is disposed between string 412 and a wall 418 to provide a flow region 420 and an annular region 422 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 414 to expand and seal the annular region. Wall 418 may be a cement or other casing or may be the wall of an open hole. Plates 216 may be positioned between swell packer 414 and couplers 460 . Couplers 460 are configured to resist lateral movement of pates 416 relative to tube 412 . An inner surface of couplers 46 contacts an outer surface of tube 412 at a region 462 . The region 462 may be knurled or otherwise textured to provide increased friction between couplers 460 and tube 412 . Couplers 460 comprise first half 460 a and a second half 460 b . Second half 460 b may be provided with recesses 462 to accommodate bolts 464 which may be used to secure first half 460 a to second half 460 b . Alternatively, a single recess may be positioned on each half in which case the halves 460 a and 460 b could be identical.
[0028] One or more of plates 416 positioned closes to swell packer 414 may be provided with extensions 456 which extend roughly parallel to tube 412 and extend from a deflection point 458 . Extensions 456 may serve to further reduce extrusion of the elastoomer material past plates 416 .
[0029] Referring to FIGS. 10 and 11 , a system 510 comprises a string 512 , shown as a production tube, swell packer 514 , and plates 516 and 517 . Swell packer 514 may comprise an elastomeric material that will expand in the presence of hydrocarbons. Swell packer 14 is positioned along an outer surface of string 512 such that packer 514 is disposed between string 512 and a wall 518 to provide a flow region 520 and an annular region 522 . When placed in or near a production zone, a portion of the hydrocarbons therein may be absorbed and cause swell packer 514 to expand and seal the annular region. Wall 518 may be a cement or other casing or may be the wall of an open hole. Plates 517 may be joined to plates 516 at a point near deflection point 534 of plate 516 . Plates 517 may be positioned on the side of plate 516 adjacent to the elastomer material.
[0030] Plates 516 may include an extension 566 extending parallel to tube 512 and may be coupled to tube 512 by fastener 568 . Alternatively, plate 516 may be welded or otherwise coupled to tube 512 . Plate 516 also includes a lateral extension 556 which extends from a deflection point 558 . Plate 517 may extend roughly parallel to portion 570 of plate 516 and comprise an extension 557 that extends roughly parallel to extension 556 from deflection point 559 . Plate 516 includes petals 530 separated by slots 532 . Likewise, plate 517 includes petals 531 separated by slots 533 . Plates 516 and 517 are configured such that the petals of one plate overlap the slots of the other.
[0031] Although the foregoing has been described with reference to exemplary embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope thereof. For example, although different example embodiments may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example embodiments or in other alternative embodiments. The present subject matter described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements. Many other changes and modifications may be made to the present invention without departing from the spirit thereof. The scope of these and other changes will become apparent from the appended claims. The steps of the methods described herein may be varied, and carried out in different sequences.
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A system for use in a wellbore is disclosed. The system may include a tube, a swell packer surrounding a portion of the tube, a first pair of plates coupled to an outer surface of the tube and positioned at a first end of the swell packer, each of the first pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals, wherein at least one of the slots of one of the first pair of plates overlaps with at least one of the petals of the second of the first pair of plates, and a second pair of plates coupled to the outer surface of the tube and positioned at a second end of the swell packer, each of the second pair of plates having a plurality of slots extending inwardly from an outer edge of the plate, the regions between slots defining petals wherein at least one of the slots of one of the second pair of plates overlaps with at least one of the petals of the second of the second pair of plates.
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FIELD
The present disclosure relates to high pressure fluid delivery systems and more particularly to a safety system for a conduit which is part of the high pressure delivery system.
BACKGROUND
A prevailing problem in high pressure fluid delivery systems such as those used to fill containers with compressed gases such as oxygen, nitrogen, carbon dioxide and the like is the risk that a conduit which is part of the fluid delivery system may fail. Typically, the conduit is constructed as a hose or the like from a hardy flexible material such as treated and reinforced rubber, neoprene, nylon, TEFLON polymer, stainless steel and the like.
However, on occasion, a conduit fails by rupturing or splitting. When a hose/conduit ruptures, at least two hazards are present. First, the two pieces of the conduit which result from the rupture are free to whip around wildly under the force of the compressed gases which are being discharged through the ruptured conduit from the container being filled and from the discharge manifold of the fluid supply. Until the conduit can be constrained, substantial risk of injury to personnel and damage to equipment exists. Second, a discharge of gas from the manifold and the container through the ruptured hose/conduit can lead to a costly waste of gas, or even worse, can fill an environment with hazardous fumes.
It would therefore be desirable to have a system which would restrain a ruptured high pressure conduit from whipping about, and at the same time would be capable of preventing gases from leaking from the conduit through the rupture.
SUMMARY
The aforementioned need is satisfied by a safety system for a fluid conduit that has first and second ends. In one variation of the system, a housing is provided at each end of the conduit and defines a valve seat. Each valve seat is normally a first predetermined distance from the other and is movable away from the other when the conduit fails. The housing includes a generally cylindrical portion and a generally tapered portion defining the valve seat, where the cylindrical portion and the tapered portion meeting at a generally transverse plane.
A valve body is disposed within each housing such that the valve seats are disposed between the valve bodies. The valve bodies and the valve seats cooperate to define valves. A connector is connected to each of the valve bodies and holds the valve bodies apart a second distance which is greater than the first distance so that each valve body resides generally in the cylindrical portion of the corresponding housing until the conduit fails. A retainer is disposed within each housing and cooperates with the connector to retain the valve bodies against movement to permit fluid to flow through the conduit until the conduit fails.
The connector is operative when the conduit fails and the valve seats move away from each other to retain the valve bodies at the second distance so that the valve seats move toward the valve bodies and close the valves, or if the distance between the valve seats does not change, to permit the valve bodies to move toward each other so that the valve bodies move toward the valve seats to close the valves. Each valve body moves a third distance into contact with and past the plane and into the tapered portion of the corresponding housing to close the corresponding valve when the conduit fails. The third distance corresponds to a compression zone between the valve body and the corresponding valve seat and is sufficiently large to reduce heat generated in the compression zone from adiabatic compression of the fluid flowing through the compression zone.
In another variation of the system, two heat-dissipating ribs are externally positioned on each housing adjacent the compression zone of the housing to dissipate heat generated thereat. Each rib extends generally circumferentially about the housing and generally radially from the housing. In yet another variation of the system, the connector is a generally helical spring residing within the conduit and sized to be in substantially complete contact with an interior wall of the conduit so that the spring provides structural strength to the conduit.
In another variation, a third housing is positioned in series with the conduit and coupled to one of the first and second housings to permit fluid to flow through the conduit in a first direction and to prevent flow through the conduit in a second direction opposite the first direction. The valve body of the third housing is un-tethered and acts as a one-way check valve.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary as well as the following detailed description of various embodiments of the present subject matter will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the various embodiments of the subject matter, there are shown in the drawings embodiments that are presently preferred. As should be understood, however, the subject matter considered to be inventive is not limited to the precise arrangements and instrumentalities shown. In the drawings:
FIG. 1 is a schematic drawing of an apparatus for filling a cylinder or the like with compressed fluid under high pressure.
FIG. 2 is a cut-away view of a hose or other conduit constructed in accordance with one form of the inventive subject matter with the valves therein positioned to permit fluid flow.
FIG. 3 is a section view taken along lines 3 - 3 of FIG. 2 .
FIG. 4 is a cut-away view similar to that of FIG. 2 but showing the valves positioned to block fluid flow.
FIG. 5 is a partial cut-away view similar to that of FIGS. 2 and 4 and shows a valve housing constructed to include a relatively larger compression zone.
FIG. 6 is a partial cut-away view similar to that of FIGS. 2 and 4 and shows a valve housing constructed to include exterior heat-dissipating ribs adjacent the compression zone.
FIG. 7 is a cut-away view similar to that of FIGS. 2 and 4 and shows a conduit constructed to include a spring rather than a cable.
FIG. 8 is a partial cut-away view similar to that of FIGS. 2 and 4 and shows an additional valve housing in-line with a hose such as that of FIGS. 2 , 5 , and 6 and acting as a one-way check valve.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Certain terminology may be used in the following description for convenience only and is not considered to be limiting. For example, the words “left”, “right”, “upper”, “lower”, “top”, “bottom”, “front”, and “back” designate directions in the drawings to which reference is made. Likewise, the words “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of the referenced object. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.
In FIG. 1 a delivery system for filling containers with compressed fluids is illustrated as comprising fluid supply 10 such as a reservoir, or fluid compressing means, or the like. The supply 10 may be connected by a discharge manifold 12 to a plurality of containers 14 to which the fluid is to be transferred.
Typically, the containers 14 may be gas cylinders which are well known in the art. Conduits 20 which may be elongated flexible members are connected between the discharge manifold 12 and the containers 14 .
Typically, the conduits 20 are hoses made of reinforced neoprene, rubber, neoprene, nylon, TEFLON polymer, stainless steel and the like so that they have a high degree of flexibility and are capable of withstanding the high pressures which they encounter from the compressed fluids that move through them.
In FIG. 2 one of the conduits 20 is shown in detail. The conduit 20 includes a housing 22 at one end and an identical housing 24 at its other end. The housings 22 and 24 are connectors which enable the conduit 20 to be connected to other elements in the fluid handling system. Since the two housings are identical, the following detailed description of housing 22 will also suffice as a description of housing 24 . Housing 22 is connected to conduit 20 by a ferrule 26 which cooperates with a complementary elongated cylindrical hollow member 30 that extends from the end wall 32 of the housing 22 and into the passage 34 defined by the conduit 20 .
As best seen in FIG. 2 the housing 22 is an elongated, hollow, cylindrical element which is connected by end wall 32 and member 30 to the conduit 20 and has threads 36 at its other end for connection to another element in the fluid handling system. The housing 22 has an inner wall that includes a valve chamber 38 which is defined by a ledge 40 that faces away from end wall 32 and a tapered valve seat 42 that lies adjacent end wall 32 . The tapered valve seat 42 lies between the ledge 40 and the end wall 32 and faces ledge 40 .
As explained above, member 30 cooperates with the ferrule 26 to clamp the conduit 20 between them so that the housing 22 is securely connected to the conduit 20 for the receipt of and transmission of fluid under high pressure. It also serves as a cable guide as will be explained herein. A valve body 44 is disposed in the valve chamber 38 . Preferably, the valve body 44 includes an elongated, cylindrical member 46 having a tapered end 48 and a rear wall 50 . The taper at end 48 corresponds to the taper of the valve seat 42 so that they can cooperate to prevent the flow of fluid when they are in engagement with each other. A distal end 52 extends from the rear wall 50 of the valve body 40 and comprises an elongated stem-like member 54 of relatively small diameter relative to the elongated, cylindrical member 46 . Stem-like member 54 extends away from the valve seat 40 .
Each of the valve bodies 44 and stem-like members 54 include a longitudinally extending, axial passage 56 of relatively small diameter through which a relatively stiff cable 58 or other suitable flexible and bendable member of predetermined length can be received. The valve body 44 may be connected to the cable 58 by swaging, welding, or other suitable means so that the cable 58 cannot separated from the valve body 44 under the strong forces which will be present should the conduit 20 rupture.
Referring to FIGS. 2 and 3 , valve body retainers 60 and 62 are provided in housings 22 and 24 respectively. Since the two retainers 60 and 62 are identical the following detailed description of retainer 60 will also suffice as a description of retainer 62 . Referring to FIG. 3 , retainer 60 is a disc that includes a generally annular central member 64 having a plurality of arms 66 extending radially outwardly from it. The center of the annular member 64 comprises an aperture 68 . Retainers 60 and 62 are disposed on ledges 40 in each housing 22 and 24 . Each retainer is fixed on the ledge by being force fit, clamped, welded or secured by any suitable means that will hold it in place for a reason that will become apparent. The distance between the retainers 60 and 62 is about the same as the distance between the rear walls 50 of the valve bodies 44 .
As best seen in FIG. 2 the member 30 and the stiffness of the cable 58 cause the valve bodies 44 to lie with their rear walls 50 against their respective retainers 60 and 62 with their respective stems 54 extending through the apertures 68 . Under normal operating conditions, compressed fluids flow through conduit 20 , through the fluid passages 70 defined by the space between the arms 66 on each retainer 60 and 62 and the inner wall of the housings 22 and 24 , and through the opening between each valve seat 42 and its respective valve body 44 . Since the cable 58 is confined by the wall of conduit 20 , and is long enough arid sufficiently stiff to keep the valve bodies in engagement with the retainers 60 and 62 , as is apparent from FIG. 2 , neither valve body can move within its chamber since such movement is blocked by the retainer at the other end of the conduit.
Should the conduit 20 fail by either splitting or by rupture, the valve bodies 44 and valve seats 42 will move into engagement with each other thereby stopping the flow through the conduit 20 at each of its ends as seen in FIG. 4 . Accordingly, not only will discharge from the supply manifold be stopped, but also discharge from the container being filled will be stopped.
If the supply 10 or one of the containers 14 should fall during filling, the conduit 20 may fail. In this case the ends of the conduit will move with the item to which they are connected. Therefore, the valve seats 42 will be drawn away from each other and into engagement with their respective valve bodies 44 since the cable 58 will be drawn taut by the movement the conduit ends away from each other.
If the supply 10 and containers 14 are fixed, they will not be displaced when the conduit fails. In this case the valve bodies 44 will be urged into engagement with their respective valve seats 42 due to the pressure differential across the valve bodies 44 in that there is still high pressure fluid in the supply 10 and container 14 bearing against the valve bodies 44 . When conduit 20 fails, cable 58 is released from its confinement within the conduit and can flex to permit the valve bodies 44 to move toward the valve seats 42 . Further, because the cable 58 extends through the conduit 20 , it will serve as a guide for a ruptured conduit, thereby preventing the ends of the conduit from being whipped about by the discharging fluid. Still further, even if the cable were to fail as a result of the rupture, fluid flow will still be stopped at each end of the conduit since the cable 58 will not be holding the valve bodies 44 apart. It is significant to note that the advantages of the inventive subject matter are achieved by a structure that is entirely within the conduit. Thus, there is no external apparatus that might be inadvertently snagged, damaged or destroyed thereby rendering the features of the inventive subject matter unavailable when needed.
In various embodiments, it is to be understood that the device and method disclosed above can be used with conduits 20 of varying sizes and materials. For example, the conduit 20 can be a relatively flexible hose or tube or even a relatively rigid pipe or duct, among other things. Moreover, it is to be understood that the plunger-type valve body 44 may alternately be embodied as a number of sliding members, as is the case in the aforementioned U.S. Pat. Nos. 5,357,998 or as 6,260,569 and 6,546,947 as a flapper, each of which is incorporated herein by reference in its entirety.
In one variation of embodiments of the inventive subject matter, and turning now to FIG. 5 , a plunger-type valve body 44 is provided in the housing 22 / 24 in a manner similar to that shown in FIG. 2 . Here, though, the valve body 44 is positioned against the retainer 60 during normal, open operation and is relatively farther from the tapered valve seat 42 . Accordingly, and as shown in FIG. 5 , during such normal, open operation, the valve body 44 and the valve seat 42 define therebetween a compression zone 100 within the valve chamber 38 that is relatively larger as compared with that of FIG. 2 .
With such a relatively larger compression zone 100 as is shown in FIG. 5 , it should be understood that the housing 22 / 24 does not suffer as much from excessive heat generated by the fluid flowing therethrough, as compared with the housing 22 / 24 of FIG. 2 . In particular, it is to be appreciated that such heat arises from adiabatic compression that occurs when the fluid enters such compression zone 100 , and such heat can be significant, especially as the pressure and/or the flow rate of the fluid increases. Notably, such heat if extreme can even damage or destroy the housing 22 / 24 . Thus, by increasing the volume of the compression zone 100 , as is shown in FIG. 5 compared with FIG. 2 , the effect of adiabatic compression is spread out over the increased volume and thereby reduced. As a result, heat generated in connection with such adiabatic compression is likewise reduced.
In various embodiments, the compression zone 100 is constructed to be relatively larger as is shown in FIG. 5 by reducing the axial length of the plunger-type valve body 44 , increasing the axial length of the valve chamber 38 , or a combination thereof. While such relatively larger compression zone 100 may be quantified in many appropriate forms, it is to be appreciated that in the normal, open position of the valve body 44 in FIG. 2 , the tapered end 48 of the valve body 44 just contacts the generally transverse plane P ( FIG. 5 ) where the valve chamber 38 begins to taper to the tapered valve seat 42 thereof.
In contrast, in the normal, open position of the valve body 44 in FIG. 5 , the tapered end 48 of the valve body 44 has not as yet approached the plane P that separates the cylindrical portion and the tapered portion of the valve chamber 38 . As should be understood, the valve body 44 resides within such cylindrical portion when in the normal, open position. Thus, with the relatively larger compression zone 100 in FIG. 5 , the tapered end 48 of the valve body 44 moves into contact with and past the aforementioned plane P when the valve body 44 moves from the normal, open position (as shown in FIG. 5 ) to the closed position.
Thus, the valve body 44 of FIG. 5 as compared to that of FIG. 2 must travel a farther distance to the closed position where the tapered end 48 thereof encounters the tapered valve seat 42 . As shown in FIG. 5 , such distance is about 50 percent greater than the distance from the plane P to the closed position, although other distances may also be provided.
In another variation of embodiments of the present inventive subject matter, and turning now to FIG. 6 , the exterior of the housing 22 / 24 is provided with ribs 102 in the axial region of the compression zone 100 . As should be understood, each rib 102 extends generally circumferentially about the exterior of the housing 22 / 24 adjacent the compression zone 100 , generally radially from the housing 22 / 24 a relatively short distance of perhaps an eighth of an inch, a quarter of an inch, a half of an inch, or so, and also generally axially with respect to the housing 22 / 24 a relatively short distance of perhaps an eighth of an inch, a quarter of an inch, or so.
As may be appreciated, such ribs 102 act to dissipate the heat generated by the fluid flowing through the housing 22 / 24 . Again, it is to be appreciated that such heat arises from adiabatic compression that occurs when the fluid enters such compression zone 100 . Here, and as should be understood, the ribs dissipate the heat by increasing the surface area between the housing 22 / 24 and the surrounding environment and thereby increasing the rate of heat transfer. Notably, in various embodiments, only a limited number of ribs 102 are provided, such as for example one or two ribs 102 . Thus, tooling required to impart the housing 22 / 24 with such ribs 102 during manufacturing is minimized.
In yet another variation of embodiments of the present inventive subject matter, the cable 58 within the conduit 20 is constructed from a non-ferrous material. As may be appreciated, such a non-ferrous material for the cable 58 is particularly useful when the fluid in the conduit 20 is oxygen or the like which would cause a ferrous cable 58 to rust. Similarly, in yet another variation of embodiments of the present inventive subject matter, the cable 58 within the conduit 20 is constructed from a rod material having increased rigidity. As may be appreciated here, such increased rigidity may be required in situations where the conduit 20 is especially large in cross-sectional diameter, such as for example about four inches or so.
In still another variation of embodiments of the present inventive subject matter, the cable 58 within the conduit 20 is replaced by a generally helical spring. As may be appreciated, the spring 104 ( FIG. 7 ) is appropriately sized and configured to urge each valve body 44 into the normal, open position against the respective retainer 60 during normal operation of the conduit 20 , and also to move each valve body 44 into the closed position against the tapered valve seat 42 in the event that the conduit 20 fails. Thus, the spring 104 functions in a similar manner as the cable 58 .
Notably, and as seen in FIG. 7 , the spring 104 resides within the interior of the conduit 20 and is sized to be in substantially complete contact with the interior wall of the conduit 20 . Thus, the spring 104 additionally functions to provide the conduit 20 with structural strength. As such, the conduit 20 may be constructed from a relatively lighter grade of material, thus reducing material costs in connection with such conduit 20 .
As may be appreciated, the use of a spring 104 in the conduit 20 prompts a consideration of whether the conduit 20 with the spring 104 therein can be coiled, such as may be performed to store the conduit 20 and/or package the conduit for shipping and the like. In particular, if the spring 104 is too large in diameter relative to the length of the conduit 20 , coiling the conduit 20 with the spring 104 therein may be difficult if not impossible, especially if the coiling itself has a relatively small diameter. Essentially, the spring 104 may bunch if the coiling is too tight, or may prevent such coiling from being performed.
Generally, a conduit 20 with a spring 104 of relatively modest diameter, perhaps on the order of ¼ to ½ inch or so, can be coiled with relative ease, presuming the length of the conduit 20 is beyond of a minimum, perhaps on the order of 7 feet or so. In contrast, a conduit 20 with a spring 104 of relatively large diameter, perhaps on the order of 4 to 8 inches or so, cannot be coiled in any significant manner regardless of the length of the conduit 20 . Thus, in various embodiments of the present innovation, the length of the conduit 20 is taken into consideration when determining whether a spring 104 of a set diameter is employed therein, and also the need to coil the conduit 20 is taken into consideration when determining whether a spring 104 of a set diameter is employed therein.
In yet another variation of embodiments of the present inventive subject matter, and turning now to FIG. 8 , a valve housing 106 similar to if not identical with the valve housings 22 / 24 is placed in-line/in series with the hose or conduit 20 . As shown in FIG. 8 (and FIGS. 5 and 6 as well), the valve arrangement in each of the housings 22 / 24 / 106 is a poppet-type valve arrangement, although other types of valve arrangements may also be employed in each of the housings 22 / 24 / 106 , such as for example a flapper-type valve arrangement or a multi-wedge valve arrangement.
Notably, the valve body 44 within the valve housing 106 is not tethered to any cable such as the cable 58 set forth above, any spring such as the spring 104 set forth above, or any other type of tether. Accordingly, the valve body 44 effectively floats within the housing 106 and is free to slide generally axially from one side where the valve body 44 is generally in contact with the valve retainer 60 to the opposite side where the valve body 44 is generally in contact with the valve seat 42 . As may be appreciated, the position of the valve body 44 is thus determined by the general flow of fluid within the housing 106 and also the housings 22 / 24 and conduit 20 .
In particular, and as shown in FIG. 8 , when fluid is flowing in what has been designated as a normal direction from left to right, the valve body 44 is urged by such normal flow to the right and into stopping contact with the retainer 60 . As such, the valve body 44 is in an open position where the normal flow of the fluid is not generally impeded by the valve body 44 and retainer 60 . In contrast, when fluid is flowing in a backward direction opposite the normal direction and from right to left, the valve body 44 is urged by such backward flow to the left and into stopping contact with the valve seat 42 . As such, the valve body 44 is in a closed position where the backward flow of the fluid is generally impeded by the valve body 44 and valve seat 42 . Thus, the housing 106 as installed in-line/in series with the conduit 20 acts as a one-way check valve that generally allows the normal flow and generally prevents the backward flow of the fluid through the conduit 20 .
As may be appreciated, the housing 106 that implements the one-way check valve for the conduit 20 is placed in-line or in series with such conduit by being appropriately coupled at an appropriate end thereof to one of the housings 22 / 24 by way of a coupling device 108 . Such coupling device 108 may be rigid or flexible and may be any appropriate coupling device, such as for example a length of coupling hose, a copper or brass pipe, a length of conduit such as the conduit 20 , or the like. The housing 106 may be coupled at the other end thereof to an external element by way of threads akin to the threads 36 (not shown), another coupling hose or conduit attached to a ferrule (not shown) on the housing 106 akin to the ferrule 26 , or the like.
As shown in FIG. 8 , and again, the normal flow is from the left to the right. However, such normal flow may be reversed in any of several manners. For example, the housing 106 may alternately be manufactured with the valve body 42 and retainer 60 switched and with the valve body appropriately repositioned within the housing 106 . Alternately, the housing 106 as shown may be detached from the one housing 22 / 24 and attached to the other housing 22 / 24 . Also alternately, the entire system including the housings 22 / 24 / 106 and the conduit 20 may be detached from the external elements, reversed in an end-to-end manner, and then re-attached to the external elements.
While the inventive subject matter has been described with respect to particular embodiments, it is apparent that other embodiments can be employed to achieve the intended results. Thus, the scope of the inventive subject matter should not be limited by the foregoing description, but rather only by the scope of the claims appended hereto.
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A housing at each end of a conduit defines a valve seat. A connector is connected to a valve body in each housing and holds the bodies away from the seats until the conduit fails, after which each body moves into contact with the corresponding seat. A compression zone between each body and the corresponding seat is sufficiently large to reduce heat generated thereat from adiabatic compression of the fluid flowing therethrough. In a variation, two heat-dissipating ribs are externally positioned on each housing adjacent the compression zone. In another variation, the connector is a generally helical spring within the conduit and sized to be in contact with an interior wall of the conduit so that the spring provides structural strength thereto. In another variation, a third housing is employed as a one-way check valve.
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This application is a continuation application of application Ser. No. 940,394, filed Sept. 3, 1992 abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing L-threonine by fermentation. L-threonine is not only useful as a medicament such as amino acid preparations but also utilizable as an additive for animal feed.
With respect to the fermentation process for production of L-threonine by use of a microorganism belonging to the genus Escherichia, various processes have been known; for example, a process using a microorganism having a borrelidin sensitivity (Japanese Published Examined Patent Application No. 6752/76), a process using a microorganism requiring diaminopimelic acid and methionine for growth and of which threonine biosynthesis system is resistant to feedback inhibition of threonine (Japanese Published Examined Patent Application No. 10037/81), a process using a microorganism having a resistance to at least one of rifampicin, lysine, methionine, aspartic acid and homoserine, or a decreased ability to degrade L-threonine (Japanese Published Unexamined Patent Application No. 273487/88, U.S. Pat. No. 5,017,483), a process using a microorganism having a resistance to at least one of L-serine and ethionine (Japanese Published Unexamined Patent Application No. 259088/91, European Publication No. 445830), etc.
However, the known processes are still insufficient in efficiency of the production of L-threonine. It is therefore an object of the present invention to provide a process for producing L-threonine, in higher yield and at lower cost.
SUMMARY OF THE INVENTION
According to the present invention, provided is a process for producing L-threonine which comprises culturing an L-threonine-producing microorganism belonging to the genus Escherichia and having a resistance to at least one of L-phenylalanine and L-leucine in a medium until L-threonine is produced and accumulated in the culture and recovering L-threonine therefrom.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, any microorganism can be used, so long as it belongs to the genus Escherichia, has a resistance to at least one of L-phenylalanine and L-leucine and is capable of producing L-threonine.
The suitable microorganism used in the present invention can be obtained by subjecting L-threonine-producing microorganisms belonging to the genus Escherichia to the conventional mutagenesis such as treatment with N-methyl-N'-nitro-N-nitrosoguanidine and X-ray irradiation, spreading the resulting microorganisms on a minimum medium containing L-phenylalanine or L-leucine, and picking up colonies grown on the minimum medium. Selection of the desired mutant strain is efficiently performed by using the minimum medium containing L-lysine or a salt thereof such as hydrochloride of L-lysine in an amount of one to 10 g/l. The suitable microorganism used in the present invention may also be obtained by endowing a microorganism belonging to the genus Escherichia and having a resistance to at least one of L-phenylalanine and L-leucine which microorganism is derived from a wild strain, with nutrient auxotrophy, threonine metabolism antagonist-resistance, etc. for imparting L-threonine productivity. Preferred examples of the suitable microorganism are Escherichia coli H-8309 and H-8311.
A specific example of obtaining the preferred strains is described below:
A diaminopimelic acid non-auxotrophic strain, Escherichia coli H-7700 was derived from diaminopimelic acid-auxotrophic strain Escherichia coli H-4581 (FERM BP-1411) having a methionine-requirement, an α-amino-β-hydroxyvaleric acid-resistance, a decreased ability to degrade L-threonine, a rifampicin-resistance, a lysine-resistance, a methionine-resistance, a homoserine-resistance and an aspartic acid-resistance. Further, Escherichia coli H-7700 was endowed with a resistance to L-serine and ethionine to obtain Escherichia coli H-7729 (FERM BP-2792). Escherichia coli H-7729 was subjected to a conventional mutation treatment with N-methyl-N'-nitro-N-nitrosoguanidine (0.2 mg/ml, 30° C., 30 minutes), and then spread on a minimum medium (5 g/l glucose, 2 g/l NH 4 Cl, 2 g/l KH 2 PO 4 , 0.1 g/l MgSO 4 ·7H 2 O, 20 mg/l FeSO 4 ·7H 2 O, 50 mg/l DL-methionine, 2% agar, pH 7.2) containing 10 g/l L-phenylalanine and 3 g/l L-lysine hydrochloride. After culturing at 30° C. for 2 to 6 days, larger colonies grown were picked up as the strain having resistance to L-phenylalanine and subjected to the L-threonine production test to select strains having L-threonine-producing ability greater than that of the parent strain. Among the thus selected strains is Escherichia coli H-8311.
Escherichia coli H-8309 having a resistance to L-leucine was obtained in a manner similar to the procedure for obtaining H-8311 strain except that H-7700 strain was used as the parent strain in place of H-7729 strain, and that L-leucine (6 g/l) was contained in the aforesaid minimum medium in place of L-phenylalanine.
The H-8311 and H-8309 strains thus obtained were deposited on Aug. 21, 1991 in the Fermentation Research Institute, Agency of Industrial Science and Technology, 1-3, Higashi 1 chome Tsukuba-shi Ibaraki-ken 305, Japan under the Budapest Treaty with accession numbers FERM BP-3520 and FERM BP-3519, respectively.
With respect to H-8311 and H-8309 strains, degrees of resistance to L-phenylalanine and L-leucine were examined, as compared to that of the corresponding parent strain. The degree of resistance was expressed in terms of degree of growth. The mutant strains and the parent strains each were cultured for 24 hours on a complete medium (10 g/l trypton, 5 g/l yeast extract, 10 g/l NaCl, 2% agar, pH 7.5) in a slant . The cultured strains were suspended in a sterilized water. The obtained suspension was spread on a minimum medium (5 g/l glucose, 2 g/l NH 4 Cl, 2 g/l KH 2 PO 4 , 0.1 g/l MgSO 4 ·7H 2 O, 20 mg/l FeSO 4 ·7H 2 O, 50 mg/l DL-methionine, 2 g/l L-lysine hydrochloride, 2% agar, pH 7.2) containing L-phenylalanine and L-leucine in the amounts shown in Table 1 and culturing was carried out at 30° C. for 72 hours. The results are shown in Table 1.
TABLE I______________________________________Amount Strain(g/l) H-7729 H-8311 H-7700 H-8309______________________________________Phe0 + + + +1 ± + ± +10 - + - ±Leu0 + + + +1 ± + ± +6 - + - +______________________________________ +: sufficient growth ±: moderate growth -: no growth
In the production of L-threonine using the microorganism of the present invention, any conventional method for culturing bacteria is applicable. As the medium, any of a synthetic medium and a natural medium may be used so long as it suitably contains carbon sources, nitrogen sources, inorganic substances and other nutrients required for the strains used.
As the carbon source, carbohydrates such as glucose, fructose, lactose, molasses, cellulose hydrolyzate, hydrolyzate of crude sugar, starch hydrolyzate, etc.; and organic acids such as pyruvic acid, acetic acid, fumaric acid, malic acid, lactic acid, etc. can be used. Depending upon assimilability of the microorganism, glycerine, alcohols such as ethanol, etc. can also be used.
As the nitrogen source, ammonia, ammonium salts of inorganic or organic acids, such as ammonium chloride, ammonium sulfate, ammonium acetate, ammonium phosphate, etc.; amines and other nitrogen-containing compounds, peptone, meat extract, corn steep liquor, casein hydrolyzate, soybean cake hydrolyzate, various cultured cells and their digested product, etc. can be used.
As the inorganic substances, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, magnesium phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate, calcium carbonate, etc. can be used.
Culturing is carried out under aerobic conditions, e.g. by shaking culture, agitation submerged culture, etc. at a temperature of 20° to 40° C., preferably 25° to 38° C. The pH of the medium is in the range of 5 to 9, and is preferably maintained at around neutrality. The pH is adjusted with calcium carbonate, inorganic or organic acids, alkaline solutions, ammonia, a pH buffer agent or the like. Usually, after culturing for 2 to 7 days, L-threonine is accumulated in the culture.
After the completion of the culturing, precipitates such as cells, etc. are removed from the culture by means of centrifugation, etc. By using ion exchange treatment, concentration, salting out, etc. in combination, L-threonine can be recovered from the culture.
Hereafter the present invention is illustrated by the following Example.
EXAMPLE 1
Production test of L-threonine
L-threonine production test is carried out by culturing the above-mentioned mutant strains. Escherichia coli H-8311 and its parent strain Escherichia coli H-7729, and Escherichia coli H-8309 and its parent strain Escherichia coli H-7700 each were cultured with shaking at 30° C. for 16 hours in a seed medium (pH 7.4) containing 20 g/l glucose, 10 g/l peptone, 10 g/l yeast extract and 2.5 g/l NaCl. 100 ml of the resulting seed culture was transferred to 1 liter of a fermentation medium having the following composition charged in a 2 l-jar fermentor and culturing was carried out at 30° C. with stirring at 800 rpm and an aeration rate of 1 liter/min for 80 hours. During the culturing, pH control and supply of nitrogen source were made by aqueous ammonia, whereby the pH was kept at about 6.5±0.2, and glucose was supplied at an appropriate time. After the completion of the culturing, the amount of L-threonine accumulated was quantitatively determined by high performance liquid chromatography. The results are shown in Table 2.
Composition of fermentation medium:
40 g/l glucose, 12 g/l (NH 4 ) 2 SO 4 , 2 g/l KH 2 PO 4 , 0.1 g/l MgSO 4 .7H 2 O, 5 g/l corn steep liquor, 0.3 g/l DL-methionine, (pH 7.4)
One liter of the L-threonine-containing culture obtained by culturing H-8311 strain was centrifuged (3000 rpm, 10 minutes) to remove the cells and other impurities therefrom. The thus obtained supernatant was passed through a column packed with strongly acidic cationic ion exchange resin DIAION SKIB (type H + ; product of Mitsubishi Kasei Corporation, Japan) to adsorb L-threonine thereon. The column was washed with water, and subjected to elution with 0.5N aqueous ammonia to collect L-threonine fractions. The collected fractions were concentrated and ethanol was added to the concentrate. By storing the mixture under cooling, 39.5 g of L-threonine crystals having purity of 98% or higher was obtained.
TABLE 2______________________________________Strain L-Threonine (g/l)______________________________________H-7700 3.4H-8309 10.4H-7729 37.2H-8311 48.7______________________________________
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Disclosed is a process for producing L-threonine, which comprises culturing an L-threonine-producing microorganism belonging to the genus Escherichia and having a resistance to at least one of L-phenylalanine and L-leucine in a medium until L-threonine is produced and accumulated in the culture, and recovering L-threonine therefrom.
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BACKGROUND OF THE INVENTION
The current commercial specifications for digital audio, compact discs ("CD-DA") i.e., the format for storing and playing high fidelity audio tracks, and compact disc-read only memory ("CD-ROM"), i.e., the format for storing and retrieving data intended to be accessed by general purpose personal computers, have been co-developed by Philips N.V. and Sony Corporation. These specifications are commonly referred to as the Red Book (for compact disc digital audio) and the Yellow Book (for CD-ROM) each of which is a technical specification created by Philips N.V. and Sony Corporation entitled "Compact Disc Digital Audio System Description" and "Compact Disc-Read Only Memory System Description," respectively. A commercial specification for CD-DA is also published by the international Electrotechnical Commission, entitled IEC Publication 908 "Compact disc digital audio system."
In addition to the information structure and layout for CD-ROM, the CD-ROM outlines the specification for placing CD-DA audio tracks on a CD-ROM disc. This specification is commonly called the Multimode format. See FIGS. 1 and 5.
However, for reasons discussed below, the Multimode format has not been fully accepted by the audio industry as a suitable distribution medium for audio compact discs that also contain CD-ROM material. With this in mind, a set of special methodologies have been developed which define alternate methods for placing CD-ROM and CD-DA audio tracks on the same disc. These methodologies are referred to herein as the invented Multimode methodologies.
The Multimode format is not fully accepted by the audio industry for the following reasons:
(a) According to the Multimode format, the CD-ROM volume must be placed in Track 1, Index 1 while the CD-DA audio selections are placed in tracks 2, 3, . . . , N as shown in FIG. 1. For this case, Track 1, Index 0 must be 2 seconds long and usually consists of block structured CD-ROM Mode 1 data with the user data field set to 2048 bytes of binary zeroes. (On a pure CD-DA disc, Track 1, Index 0 is 2-3 seconds long and contains digital silence.) Standard compact disc audio players will attempt to "play" the CD-ROM information in Track 1, Index 1. Therefore, unless notified to use the "NEXT TRACK" entry on the player's control panel or remote, the end-user will experience a very long pause before the first CD-DA audio track is heard. The length of this pause will be equal to the "real-time" length of the CD-ROM track.
(b) In relation to the problem listed in (a), a few first generation compact disc audio players do not possess the control circuitry required to detect and then mute CD-ROM tracks. In these instances, the compact disc audio player attempts to convert the CD-ROM information into an analog signal. The resulting signal is passed through the speaker system as full volume static. This can be very damaging to the speakers as well as to the listener's hearing.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the layout of a prior art Multimode format compact disc.
FIG. 2 shows the layout of a Multimode format compact disc according to methodology #1 of the present invention.
FIG. 3 shows the layout of a Multimode format compact disc according to methodology #2 of the present invention.
FIG. 4 shows the layout of a Multimode format compact disc according to methodology #3 of the present invention.
FIG. 5 shows another view of the layout of FIG. 1.
FIG. 6 shows another view of the layout of FIG. 2.
FIG. 7 shows another view of the layout of FIG. 3.
FIG. 8 shows another view of the layout of FIG. 4.
SUMMARY OF THE INVENTION
While the standard Multimode format is based on the placement of CD-DA audio tracks on a CD-ROM disc, the invented Multimode methodologies focus on the placement of a special CD-ROM area on a CD-DA audio disc. The major difference between the standard Multimode format and the invented Multimode methodologies is the emphasis placed on consumer platforms. The standard Multimode format places more emphasis on the CD-ROM consumer platform; while the invented Multimode methodologies place more emphasis on the audio compact disc consumer platform.
The invented Multimode methodologies can be used for the distribution of audio compact discs that also contain a special CD-ROM area that can store text, graphics, animations, video, or interactive program material. Although the primary target for audio compact discs that also contain a special CD-ROM area is the compact disc audio market, most consumers who possess the appropriate CD-ROM hardware and software can access the special information area on the disc.
Presently, there are three (3) methodologies embodying the invention. Each methodology utilizes a different method for placing a CD-ROM information area on a CD-DA audio disc.
DETAILED DESCRIPTION OF THE INVENTION
Methodology #1: CD-ROM DATA FILES--LAST TRACK
In methodology #1 as shown in FIGS. 2 and 6, the CD-ROM boot blocks are placed in Track 1, Index 1. The CD-DA audio tracks are placed in tracks (2, 3, . . . , N). The CD-ROM data files are placed in track (N+1).
The volume and file structure of the CD-ROM portion of the disc uses an industry standard known as ISO9660. Track 1, Index 1 of the disc contains the boot block composed of the primary volume descriptors (PVD), root directory, and path tables for the entire CD-ROM volume and other volume specific identifiers as needed according to ISO9660. Therefore, Track 1 is very short (usually <4 seconds, including PostGap. A PostGap is an area added to the end of a data track that is followed by another type of track; such as an audio track. If the format for the data track is CD-ROM Mode 1, the PostGap should also be CD-ROM Mode 1 format with the user data field set to 2048 bytes of binary zeroes.
The root directory and path tables of Track 1, Index 1 point to the data files of the volume. These data files are contained in the last track of the disc (after all CD-DA audio tracks).
Before creation of the ISO9660 volume, an absolute starting location for the placement of the data files is calculated by adding the following track and index lengths:
______________________________________ Track 1, Index 0 length - Rom (must be 00:02:00 mm:ss:ff)+Track 1, Index 1 length - Rom (usually 00:04:00 mm:ss:ff)+Track 2, Index 0 length - AUD (usually 00:02:00 mm:ss:ff)+Track 2, Index 1 length - AUD (first CD-DA audio)+Track 3, Index 0 length - AUD (usually 00:02:00 mm:ss:ff)+Track 3, Index 1 length - AUD (second CD-DA audio)• • • • .+Track N, Index 0 length - AUD (usually 00:02:00 mm:ss:ff)+Track N, Index 1 length - AUD (last CD-DA audio)+Track (N+1), Index 0 - AUD/ROM (usually 00:03:00mm:ss:ff)=Absolute starting location for the placement of data filesexpressed as mm:ss:ff(where ROM represents the length in mm:ss:ff of a CD-ROMselection and AUD represents the length in mm:ss:ff of aCD-DA audio selection).______________________________________
The Track (N+1), Index 0 or Pre-gap selection should consist of two parts, Pre-gap 1 and Pre-gap 2. Pre-gap 1 should be at least 1 second long and consist of digital silence. Pre-gap 2 should be at least 2 seconds long and consist of block structured CD-ROM Mode 1 data with user data fields set equal to binary zeroes.
This absolute time can be translated into a logical sector number (LSN), by the following equation:
LSN={[(mm*60)+ss]*75+ff}-150.
This absolute location is equivalent to the sum of the lengths of all previous pauses (Index 0) and tracks (including PostGap). During the ISO9660 formatting process, the data files are arranged in the volume starting at the pre-calculated absolute location. The resulting ISO9660 volume contains a large gap (i.e., "dead" space containing no useful information) between the boot blocks and the data file area. The ISO9660 volume is then partitioned into two files; one containing the boot blocks (usually blocks 0-150) and one containing the data file area, starting with the first block of the first file and ending with the last block of the last file in the data file area.
During the disc formatting process, the boot blocks (e.g., boot block file) for the ISO9660 volume are placed in Track 1, Index 1. Track 1, Index 0 must be 2 seconds long (same as required by the current commercial CD-ROM specifications) and usually consists of block structured CD-ROM Mode 1 data with the user data field set to 2048 bytes of binary zeroes.
The CD-DA audio tracks are placed in tracks 2, 3, . . . N. Track 2 begins with a minimum pause (Track 2, Index 0) of 2 seconds containing digital silence.
The data file area (previously stored as a separate file) is placed at the precalculated location with track number N+1. The header field found in each of the data file sectors must be generated to correspond to the Logical Sector Number (LSN) stored in the root directory and path tables of the volume without any tolerance. For example, for LSN=4500, the header field must equal 01:02:00 mm:ss:ff since one second corresponds to 75 sectors and 4500/75 equals 60 seconds plus the 2 seconds for Track 1, Index 0. In addition, the header field should coincide with the corresponding absolute disc time (stored in the Q-channel of the disc); such that the disc "skew" is equal to 0.
The ISO9660 Volume/File Specification and the installed base of CD-ROM device drivers require that the boot blocks be placed at the beginning of a CD-ROM disc. However, discs conforming to this first methodology possess a very short track 1 (usually less than 4 seconds). Therefore, the audio discrepancies listed above are minimized at the beginning of the disc.
The largest portion of the CD-ROM volume is placed at the end of the disc. Therefore, CD audio players will experience those same audio discrepancies listed above at the end of this disc. However, these discrepancies can be suppressed with proper product documentation or by including a verbal warning statement at the end of the last audio track (e.g., WARNING: THE FOLLOWING INFORMATION TRACK CONTAINS CD-ROM INFORMATION. IT IS RECOMMENDED THAT . . . ).
Due to the location of the data files in relation to the root directory/path tables (e.g., beginning of disc) and the physical dimensions of the disc (RPMs decrease as the playback head moves radically outward on the disc), average access time of the program material is higher than normal.
For the first methodology, the ISO9660 volume must be created with premastering software that allows the user to control the physical placement of the data files within the volume. The disc formatting process can be accomplished by transferring the boot block file, all CD-DA audio tracks, and finally the data area file to consecutive files on standard 8 mm Exabyte tape. The disc layout can be generated using premastering software that supports DDP (Disc Description Protocol--ANSI Z39.72-199X). Various commercially available premastering products include the tools necessary to perform this type of disc formatting.
Methodology #2: CD-ROM VOLUME--TRACK 1, INDEX 0
In methodology #2 as shown in FIGS. 3 and 7, the entire CD-ROM Volume is placed in Track 1, Index 0. The first CD-DA audio track is placed in Track 1, Index 1. All other CD-DA audio tracks are placed in tracks 2, 3, . . . , N.
The volume and file structure is ISO9660 in Track 1, Index 0. In other words, Track 1, Index 0 of the disc contains the entire CD-ROM volume; including primary volume descriptors (PVD), root directory, path tables, and the data file area.
During the disc formatting process, the CD-ROM volume is positioned in Track 1, Index 0 according to the ISO9660 descriptor location requirements. For example, the primary volume descriptor is placed at LSN 16 (Logical Sector Number 16) with a Sector header time of 00:02:16 (mm:ss:ff). This usually requires a 2 second offset (150 empty CD-ROM Mode 1 sectors starting at an absolute disc time of 00:00:00 mm:ss:ff) placed before the CD-ROM volume.
The absolute disc time (stored in the Q-channel of the disc) should coincide with the time stored in the sector header such that the resulting disc skew is 0.
The first CD-DA audio track is place in Track 1, Index 1 (following a longer than normal Track 1, Index 0 which contains the CD-ROM information area). All other CD-DA audio tracks follow in tracks 2, 3, . . . , N.
Most CD audio players are configured to directly access Track 1, Index 1 upon disc insertion and selection of the "PLAY" control option (unless a special track is selected or preprogrammed). Therefore, the CD-ROM information area will be skipped over during normal audio access on most CD players. Methodology #2 avoids the audio discrepancies described before for CD audio players which are so configured.
However, for systems that are not configured in this manner and begin at Track 1, Index 0, the audio discrepancies listed above would be heard.
The CD-ROM information area is fully accessible on CD-ROM configurations that access the ISO9660 volume via absolute time (e.g. independent of track and index points). It is believed that the majority of CD-ROM configurations (more specifically CD-ROM device drivers) are configured to directly access the PVD at LSN 16 (e.g., Sector header time of 00:02:16 mm:ss:ff) via absolute disc time. Once the PVD is found, the addresses for the root directory and path tables for the volume can be located (also via absolute disc time).
For the second methodology, the disc formatting process can be accomplished by transferring the entire ISO9660 volume to the first file on an 8 mm Exabyte tape. All CD-DA audio tracks can then be stored on the 8 mm Exabyte tape in the order in which they should appear on the final compact disc. The disc layout can be generated using premastering software that supports DDP (Disc Description Protocol--ANSI Z39.72-199X). Various commercially available premastering products include the tools necessary to perform this type of disc formatting.
Methodology #3: REPEAT "BOOT BLOCK"--TRACK 1, INDEX 1
Methodology #3 as shown in FIGS. 4 and 8 is very similar to methodology #2 in that the entire CD-ROM Volume is placed in Track 1, Index 0. However, methodology #3 specifies the boot blocks for the CD-ROM volume are repeated in Track 1, Index 1, with all CD-DA audio selections being placed in tracks 2, 3, . . . , N.
The volume and file structure is ISO9660. Track 1, Index 0 of the disc contains the entire CD-ROM volume, including primary volume descriptors (PVD), root directory, path tables, and data file area. Track 1, Index 1 of the disc contains the identical boot blocks for the CD-ROM volume, including the PVD, root directory, and path tables.
During the disc formatting process, the CD-ROM volume is positioned in Track 1, Index 0 according to the ISO9660 descriptor location requirements. For example, the primary volume descriptor is placed at LSN 16 (Logical Sector Number 16) with a Sector HEADER time of 00:02:16 (mm:ss:ff). This usually requires a 2 second offset (150 empty CD-ROM Mode 1 sectors starting at absolute disc time=00:00:00 mm:ss:ff) placed before the CD-ROM volume.
In addition, an exact copy of the boot blocks is repeated in Track 1, Index 1. The resulting disc contains a very short Track 1, Index 1 (usually<4 seconds, including PostGap). Since the boot blocks are an exact copy of those found in Track 1, Index 0, the root directory and path tables for both volumes point to the same absolute locations in the data file area. Therefore, CD-ROM device drivers configured to access the boot blocks in Track 1, Index 1 will still be able to access the CD-ROM information area.
For Track 1, Index 0, the absolute disc time (stored in the Q-channel of the disc) should coincide with the time stored in the sector header such that the resulting disc skew is 0.
CD-DA audio selections are placed in tracks 2, 3, . . . , N. Track 2 will begin with a minimum pause (Track 2, Index 0) of 2 seconds containing digital silence.
ISO9660 specifies that the location of the primary volume descriptor (PVD) must be LSN 16 (Logical Sector Number 16). The PVD contains the location of the root directory and path tables. Once the PVD is found, the root directory and path tables are loaded into RAM of the computer system to which the CD-ROM drive is connected and normal volume interaction usually proceeds.
However, CD-ROM device drivers vary in their method of accessing the PVD of the ISO9660 volume. Repeating the boot blocks in Track 1, Index 1 increases the number of compliant CD-ROM configurations (or CD-ROM device drivers) since most drivers which do not access the PVD at LSN 16 do access the PVD in Track 1, Index 1.
Methodology #3 offers a tradeoff, an increased end-user CD-ROM compliance for a reduction of CD-DA audio playback integrity. Discs conforming to methodology #3 possess a very short Track 1, Index 1 (usually less than 4 seconds). Therefore, the audio discrepancies listed above will be present, but in a shortened version as compared with methodology #2.
For the third methodology, the disc formatting process can be accomplished by transferring the entire ISO9660 volume to the first file on an 8 mm Exabyte tape. An exact copy of the boot blocks (e.g., boot block file) should be transferred to the 8 mm Exabyte tape as the second file. The CD-DA audio tracks should then be transferred to the 8 mm Exabyte tape in the order in which they should appear on the final compact disc. The disc layout can be generated using premastering software that supports DDP (Disc Description Protocol--ANSI Z39,72 199X). Various commercially available premastering products include the tools necessary to perform this type of disc formatting.
The following section discusses techniques for dealing with problems which may be encountered when utilizing the various methodologies described namely, CD-ROM noise shaping and recommendations for technically supporting these formats.
CD-ROM NOISE SHAPING
As discussed above, the standard Multimode disc format includes CD-ROM data in Track 1, Index 1. A few first generation CD audio players do not possess the control circuitry required to detect and then mute CD-ROM tracks. In these instances, the CD audio player attempts to convert the CD-ROM information into an analog signal. The resulting signal is passed through the speaker system as full volume static. This can be very damaging to the speakers as well as the listener.
Two of the invented Multimode methodologies require very short CD-ROM data areas (containing the boot blocks) in Track 1, Index 1. First generation CD audio players will experience the same problem (described above) with discs utilizing these methodologies (specifically with respect to methodologies #1 and #3). Although the extent of this discrepancy is minimized (from the entire length of the CD-ROM volume to about 4 seconds), there is still the possibility of passing full volume static through the speaker system.
These undesired effects could be further minimized with the use of CD-ROM noise shaping techniques. If used properly, the full volume static could be reduced to a series of "ticks". The information contributing to the "ticks" are the SYNC, HEADER, EDC, ECC, and any other "mandatory" information found in the sectors of the "boot block" area (such as volume descriptors, path tables, root directory, etc.).
This type of noise shaping is achieved by replacing the "don't care" information (e.g., all 2048 user data sectors that are not required by the ISO9660 volume; such as sectors 0-15, the 150 sectors of PostGap, and all other sectors between the PVD, Root Directory, Path Tables, etc.) in the boot blocks with a special pattern of data. This pattern of data is identical to the output of the scramble register (a register that is required during the standard CD-ROM scrambling process which is performed on all data within a sector except the synchronization field or first 12 bytes of a sector). The scramble register is a 15 bit shift register fed back according to the polynomial x 15 +x+1 and preset with the binary value 0000 0000 0000 001. During the standard CD-ROM scrambling process, the content of each CD-ROM sector (serial out--LSB first) is EXOR-ed with the output of the scramble register. (Note: the scramble register and EXOR gate is a standard CD-ROM encoding technique described in the current commercial CD-ROM specifications and must be performed during the processing of CD-ROM information for compatible decoding during playback on conventional CD-ROM players). If the majority of the "Boot Block" data consists of the same pattern of data that is found in the scramble register, the majority of the output data from the EXOR gate will be zero (since anything EXOR-ed with itself is zero). The only output data from the EXOR gate that will not equal zero will be the "mandatory" information.
The output of the EXOR gate consists of the scrambled data which is placed on the CD. However, this "noise shaped" scrambled pattern of data largely consists of digital silence. When this part of the disc is accessed by a CD audio player without the previously discussed control circuitry for CD-ROM detection and muting, the scrambled information is not de-scrambled, but grouped into audio samples and reconstructed back into an analog signal. The noise shaped analog signal results in an audible series of "ticks", rather than full volume static.
The invented Multimode methodologies are solutions for placing CD-ROM program material on CD-DA audio discs. With this in mind, it should be noted that there is not an ideal method of storing CD-ROM and CD-DA audio tracks on the same disc. No matter which format or application is used, including the standard Multimode format, a percentage of consumers will experience system or player incompatibilities.
For this reason, the following technical support steps may be employed by the application distributor.
Place a set of CD-ROM device driver on a BBS (Bulletin Board System) and distribute the BBS number with the CD product documentation. The set of CD-ROM device driver should be designed to conform with the chosen methodology and most ISO9660 CD-ROM configurations (including the Microsoft CD Extensions, various adapter cards and CD-ROM drives). Consumers that experience difficulties accessing the CD-ROM program area and have access to a modem can retrieve and use the driver for this hardware.
Audio discrepancies can be minimized with adequate product labeling. Consumer "awareness" can be increased with WARNING and/or CAUTION labels placed on the disc print, jewel case, packaging, etc.
A reserve of CD-ROM discs, fully compliant with current commercial CD-ROM specifications, could be manufactured and distributed to consumers who are experiencing incompatibility problems with the CD-ROM portion of the disc. In addition, CD-DA discs fully compliant with current commercial CD-DA specifications, except without the CD-ROM information area, can be utilized for similar distribution.
Although the foregoing description has been set forth with reference to ISO9660 compliant compact discs, depending on the driver for a specific system, the methodologies should work for other formats such as HFS as defined by Apple Computer, Inc.
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A method for combining CD-ROM and CD-DA audio data on a single compact disc to reduce the amount of noise which is heard when the compact disc is played back on a player which is not specially adapted to play compact discs with both CD-ROM and CD-DA audio data. Presently, there are three (3) methodologies embodying the invention. In the first, the CD-ROM, i.e., CD-ROM boot blocks are placed in Track 1, Index 1; the CD-DA audio tracks are placed in tracks (2, 3, . . . , N) and the CD-ROM data files are placed in track (N+1). In the second, the entire CD-ROM Volume is placed in Track 1, Index 0; the first CD-DA audio track is placed in Track 1, Index 1, and all other CD-DA audio tracks are placed in tracks 2, 3, . . . , N. In the third, the entire CD-ROM Volume is placed in Track 1, Index 0 as in the second. However, in the third, the boot blocks for the CD-ROM volume are repeated in Track 1, Index 1, with all CD-DA audio selections being placed in tracks 2, 3, . . . , N.
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BACKGROUND OF THE INVENTION
[0001] Over the past thirty years, the dangers of heavy metal bearing wastes and contaminated soils has been the subject of community pressure, public awareness and ever stricter regulatory control in order to reduce or eliminate the dangers to people directly and to the surrounding environment. The leaching of heavy metals into groundwater is a grave concern because of the danger that the drinking water supplies and the environment will become contaminated.
[0002] Heavy metal bearing wastes and contaminated soils may be deemed hazardous by the United States Environmental Protection Agency (U.S. EPA) pursuant to 40 C.F.R. Part 261 if containing heavy metals at leachable levels exceeding 100 times the drinking water standards. Any solid waste can be defined as hazardous either because it is “listed” in 40 C.F.R., Part 261 Subpart D or because it exhibits one or more of the characteristics of a hazardous waste as defined at Part 261, Subpart C. These characteristics are: (1) ignitability, (2) corrosivity, (3) reactivity, and (4) toxicity as tested under the TCLP leaching procedure.
[0003] 40 C.F.R., Part 261.24(a), contains a list of contaminants and their associated maximum allowable concentrations as solid waste. If a contaminant, such as lead and arsenic, exceeds its maximum allowable concentration, when tested using the Toxicity Characteristic Leaching Procedure (TCLP) analysis as specified at 40 C.F.R. Part 261 Appendix 2, then the subject waste is classified as TCLP hazardous. The TCLP test uses a dilute acetic acid either in de-ionized water (TCLP fluid 2) or in de-ionized water with a sodium hydroxide buffer (TCLP fluid 1). Both extracts attempt to simulate the leachate character from a decomposing trash landfill in which the hazardous waste being tested for is assumed to be disposed of in and thus subject to the acetic acid leaching condition. Waste containing leachable heavy metals is currently classified as hazardous waste due to the toxicity characteristic, if the level of TCLP analysis is above 0.2 to 100 milligrams per liter (mg/L) or parts per millions (ppm) for defined metals. The TCLP test is designed to simulate a worst-case leaching situation, that is leaching conditions that would typically be found in the interior of an actively degrading municipal landfill. Such landfills normally are slightly acidic with a pH of approximately 5±0.5. Countries outside of the US also use the TCLP test as a measure of leachability such as Thailand, Taiwan, Philippines, and Canada. Thailand also limits solubility of Cu and Zn, as these are metals of concern to Thailand groundwater. Switzerland and Japan regulate management of solid wastes by measuring heavy metals and salts as tested by a sequential leaching method using carbonated water simulating dilute acid rainwater.
[0004] Additionally, U.S. EPA land disposal restrictions prohibit the land disposal of solid wastes that leach in excess of maximum allowable concentrations upon performance of the TCLP analysis. The land disposal regulations require that hazardous wastes are treated until the heavy metals do not leach at Universal Treatment Standards (UTS) levels from the solid waste at levels above the maximum allowable concentrations prior to placement in a surface impoundment, waste pile, landfill or other land disposal unit as defined in 40 C.F.R. 260.10.
[0005] In addition to the regulatory concern of leaching potential of heavy metals from mixed solid waste disposed in solid waste landfills, the USEPA has published leaching tests which have been developed to predict the leaching potential of heavy metals from wastes and or materials that are not landfilled, but monofilled or reused in the environment without liner and leachate collection and management options. These published tests are often used to determine stabilized waste reuse suitability under remedial projects where large amounts of contaminated soils are stabilized and reused on-site as fill or base material, thus avoiding expensive transportation and disposal costs. The two most common tests used for in-place disposal leachate prediction are the Synthetic Precipitant Leaching Procedure (SPLP) USEPA Method 1310, and the Multiple Extraction Procedure (MEP) USEPA Method 1320. Although neither of these leach tests are promulgated as leach tests required under 40 CFR or CERCLA regulations, the tests are often required by regulators and compared to groundwater standards for remediation projects that dispose and/or reuse of stabilized wastes and contaminated soils on-site with either groundwater of surface water exposure potential.
[0006] Leach test conditions thus include the conditions to which a waste, material or contaminated soil is subjected during dilute acetic acid leaching (TCLP), buffered citric acid leaching (California STLC leach test), distilled water, synthetic rainwater or carbonated water leaching (SPLP, MEP, Japanese, Swiss, and SW-924).
[0007] Suitable acetic acid leach tests include the USEPA SW-846 Manual described Toxicity Characteristic Leaching Procedure (TCLP) and Extraction Procedure Toxicity Test (EP Tox) now used in Canada. Briefly, in a TCLP test, 100 grams of waste are tumbled with 2000 ml of dilute and buffered acetic acid for 18 hours. The extract solution is made up from 5.7 ml of glacial acetic acid and 64.3 ml of 1.0 normal sodium hydroxide up to 1000 ml dilution with reagent water.
[0008] Suitable acid rain leaching test includes the USEPA method 1312 Synthetic Precipitant Leaching Procedure (SPLP) which method is identical to the TCLP test with the replacement of the TCLP acetic acid with a SPLP dilute 40% nitric and 60% sulfuric acid solution at a extract solution pH level of 4.8 units for testing of wastes and soil East of the Mississippi River and a pH extract solution of 5.0 units West of the Mississippi River.
[0009] Suitable water leach tests include the Japanese leach test which tumbles 50 grams of composited waste sample in 500 ml of water for 6 hours held at pH 5.8 to 6.3, followed by centrifuge and 0.45 micron filtration prior to analyses. Another suitable distilled water CO 2 saturated method is the Swiss protocol using 100 grams of cemented waste at 1 cm 3 in two (2) sequential water baths of 2000 ml. The concentration of heavy metals and salts are measured for each bath and averaged together before comparison to the Swiss criteria.
[0010] Suitable citric acid leach tests include the California Waste Extraction Test (WET), which is described in Title 22, Section 66700, “Environmental Health” of the California Health & Safety Code. Briefly, in a WET test, 50 grams of waste are tumbled in a 1000 ml tumbler with 500 grams of sodium citrate solution for a period of 48 hours. The concentration of leached selenium is then analyzed by Inductively-Coupled Plasma (ICP) after filtration of a 100 ml aliquot from the tumbler through a 45 micron glass bead filter.
[0011] Suitable multiple extraction test include the USEPA Method 1320, a sequential extraction of solid using the SPLP test method with adjustment of the extract pH to 3.0 units, and repeating the extraction on the solid phase sample ten (10) times with each sequential extract analyzed for the heavy metal of concern.
[0012] Of specific interest regarding the present invention is stabilization of both Pb and As from one contaminated soil under a combination of leach tests including rainwater leached unsaturated zone and brackish water and rainwater saturate groundwater, Method 1312 SPLP and Method 1320 MEP conditions, as well as non-landfill conditions such as open industrial sites, waste storage cells, waste piles, waste monofills, and under Method 1311 TCLP for determination of hazardousness of any given soil, material or waste.
[0013] The present invention provides a method of reducing the leachability of combined heavy metal bearing contaminated soil including the groups Pb and As under SPLP, TCLP, and MEP while using a single step application.
[0014] Unlike the present invention, prior art additives and mixtures have focused on reducing the leachability of single heavy metals such as Lead, Arsenic, Cadmium, Chromium under TCLP and landfill leaching conditions. Prior methods using Portland cement produce a reduced permeability matrix or material with strength, whereas the present invention use of Cement Kiln Dust (CKD) acts only to reduce metals solubility and is not applied with the intent or results of significant reducing permeability or significant increasing material of waste strength. Prior art methods of As control with iron and lime combination failed to meet low level SPLP and MEP leaching requirements whereas the use of CKD in combination with insoluble phosphates and iron source provides both improved As and Pb solubility reduction. Prior teachings of the use of water soluble phosphates for Pb control cause As to increase leaching, and thus fail to meet low As TCLP, SPLP and MEP leaching standards. Prior art relating to insoluble phosphates for Pb stabilization fail to recognize the importance of using insoluble phosphates in the presence of As to avoid As leach increases under SPLP, TCLP and MEP.
[0015] U.S. Pat. No. 5,202,033 describes an in-situ method for decreasing Pb TCLP leaching from solid waste using a combination of solid waste additives and additional pH controlling agents from the source of phosphate, carbonate, and sulfates.
[0016] U.S. Pat. No. 5,037,479 discloses a method for treating highly hazardous waste containing unacceptable levels of TCLP Pb such as lead by mixing the solid waste with a buffering agent selected from the group consisting of magnesium oxide, magnesium hydroxide, reactive calcium carbonates and reactive magnesium carbonates with an additional agent which is either an acid or salt containing an anion from the group consisting of Triple Superphosphate (TSP), ammonium phosphate, diammonium phosphate, phosphoric acid, boric acid and metallic iron.
[0017] U.S. Pat. No. 4,889,640 discloses a method and mixture from treating TCLP hazardous lead by mixing the solid waste with an agent selected from the group consisting of reactive calcium carbonate, reactive magnesium carbonate and reactive calcium magnesium carbonate.
[0018] U.S. Pat. No. 4,652,381 discloses a process for treating industrial waste water contaminated with battery plant waste, such as sulfuric acid and heavy metals by treating the waste waster with calcium carbonate, calcium sulfate, calcium hydroxide to complete a separation of the heavy metals. However, this is not for use in a solid waste situation.
[0019] Unlike the present invention, however, none of the prior art solutions were designed to allow specifically for stabilization of heavy metal bearing material or waste containing more than one specific heavy metal and also providing a one-step means for achieving SPLP, TCLP and MEP leachability reduction of combinations of Pb and As in the waste or material matrix. The present invention also assures through the use of high water ratios and lack of aggregate that the material and wastes stabilized fail to form a cementious like material and thus are suitable for use and or disposal without having a cement-like permeability reduction or object strength.
SUMMARY OF THE INVENTION
[0020] The present invention discloses a combined Pb and As heavy metal bearing material, contaminated soils, or waste stabilization method under TCLP, SPLP and MEP analyses through contact of material, contaminated soils or waste with a one-step blend of stabilizing agents including water insoluble phosphate, cement kiln dust, and iron source, which are properly chosen to complement the material, contaminated soils or waste constituency and desired material or waste handling characteristics. The stabilizing agents proven effective are provided in both in dry and slurry form, and can be contacted with heavy metal bearing material, contaminated soils or wastes either prior to production such as in-stream at wastewater facilities producing sludge or in-duct prior to air pollution control and ash collection devices or after waste production in material collection devices, in-situ, or in-waste piles.
[0021] It is anticipated that the Pb and As stabilizers can be used for both RCRA compliance actions such that generated wastes, contaminated soils or materials from wastewater facilities, furnaces, incinerators and other facilities do not exceed the TCLP hazardous waste criteria under TCLP, or groundwater project limitations for SPLP and MEP under CERCLA (Superfund) response where stabilizers are added to waste piles or storage vessels previously generated. The preferred method of application of stabilizers would be in-line or in-situ within the property and facility generating the heavy metal bearing material, and thus allowed under RCRA as a in-situ, totally enclosed, in-tank or exempt method of TCLP stabilization without the need for a RCRA Part B hazardous waste treatment and storage facility permit.
DETAILED DESCRIPTION
[0022] Environmental regulations throughout the world such as those promulgated by the USEPA under RCRA and CERCLA require heavy metal bearing waste, contaminated soils and material producers to manage such in a manner safe to the environment and protective of human health. In response to these regulations, environmental engineers and scientists have developed numerous means to control heavy metals, mostly through chemical applications which convert the solubility of the material and waste character to a low solubility state and thus low exposure form, thus passing leach tests and allowing the wastes to be either reused on-site or disposed at local landfills without further and more expensive control means such as hazardous waste disposal landfills or facilities designed to provide metals stabilization. The primary focus of scientists has been on singular heavy metals such as lead, cadmium, chromium, arsenic and mercury, as these were and continue to be the most significant mass of metals contamination in soils. Materials such as paints, and cleanup site wastes such as battery acids and slag wastes from smelters are major lead sources. Recently, however, there exists a demand for control methods of heavy metals in combined form as Pb and As in contaminated soils and capable of meeting a combination of test evaluations including TCLP, SPLP and MEP.
[0023] The present invention discloses a combined Pb and As bearing material, contaminated soil or waste, stabilization method through contact of material, contaminated soil or waste with stabilizing agents including a single step application combination of water insoluble phosphates, cement kiln dust, and ferric source. The stabilizing agents found effective are available in dry or slurry form, and thus can be contacted with heavy metal bearing material prior to waste generation such as in-stream at wastewater sludge producing plants or in-duct prior to air pollution control and ash collection devices or after waste production in collection devices such as hoppers, dump valves, conveyors, dumpsters, in-situ, in-ground, or in waste piles. The stabilizers are applied in a manner to utilize cement kiln dust as a stabilizing agent and not a cement-like additive thus allowing stabilized material, contaminated soils and waste to remain suitable for fill material or relatively loose handling. The insoluble phosphate agent acts to exchange calcium ions for Pb ions in solution an form Pb substituted calcium phosphate apatite minerals, while not interfering with Ferric Oxide complexing with available As in solution to form insoluble ferric arsenate.
[0024] It is anticipated that the stabilizers can be used for both RCRA compliance actions such that generated materials from wastewater facilities, furnaces, incinerators and other facilities do not exceed appropriate SPLP and MEP groundwater criteria and/or TCLP hazardous waste criteria under TCLP or CERCLA (Superfund) response where stabilizers are added to waste piles or storage vessels previously generated and now regulated under RCRA as a hazardous waste pre-disposal. The preferred method of application of stabilizers would be in-situ, in-line within the property and facility generating the heavy metal bearing material, and thus allowed under RCRA as a totally enclosed, in-tank or exempt method of TCLP stabilization without the need for a RCRA Part B hazardous waste treatment and storage facility permit(s).
[0025] The use of water insoluble phosphates could include but not be limited to dicalcium phosphate, tricalcium phosphate, monocalcium phosphate, phosphate rock, pulverized forms of all above, and combinations thereof which would, as an example, provide various amount of water insoluble phosphate in combination with cement kiln dust and ferric source with Pb and As bearing material or waste. The water insoluble phosphate, cement kiln dust, ferric source and combination type, size, dose rate, contact duration, and application means could be engineered for each type of heavy metal bearing material, contaminated soils or waste.
[0026] Although the exact stabilization formation molecule(s) are unknown at this time, it is expected that when Pb and As come into contact with the stabilizing agent(s), low water and low acid soluble compound(s) begin to form such as a mineral phosphate, twinned mineral or precipitate through substitution or surface bonding, which is less soluble than the heavy metal element or molecule originally in the material or waste. Specifically complexing and/or twinning of Pb and As into pyromorphite amorphous crystals most likely occurs by adding calcium phosphate(s) to the material or waste at standard temperature and pressure. It also remains possible that modifications to temperature and pressure may accelerate of assist formation of minerals, although such methods are not considered optimal for this application given the need to limit cost and provide for optional field based stabilizing operations that would be complicated by the need for pressure and temperature control devices and vessels. Ferric arsenate is likely formed in solution and as a substituted surface reaction and possibly twinned into the calcium phosphate apatite mineral. The kinetics of soluble phosphate causing or contributing to As leaching is not known, but it has been observed that allowing ferric arsenate to form in the presence of water insoluble phosphates achieves a lower soluble As level from the stabilized matrix.
[0027] Examples of suitable stabilizing agents include Cement kiln dust, ferric powder, ferric sulfate, ferrous sulfate, ferric chloride, ferrous chloride, water insoluble phosphate fertilizers, phosphate rock, pulverized phosphate rock, calcium orthophosphates, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, fishbone phosphate, animal bone phosphate, herring meal, bone meal, phosphorites, and combinations thereof. The amounts of stabilizing agent used, according to the method of invention, depend on various factors including desired TCLP, SPLP, and MEP solubility reduction potential, desired mineral toxicity, and desired mineral formation relating to toxicological and site environmental control objectives. It has been found that an amount of certain stabilizing agents such as 8% Cement Kiln Dust, 0.5% Ferric powder, and 1.0% Dicalcium Phosphate by weight of Pb and As bearing contaminated soil both unsaturated and brackish groundwater saturated was sufficient for TCLP, SPLP, and MEP stabilization to less than limits of 10 parts per billion (ppb) Pb and 200 ppb As. However, the foregoing is not intended to preclude yet higher or lower usage of stabilizing agent or combinations if needed since it has been demonstrated that amounts greater than 10% CKD and 1% phosphate by weight also work, but are more costly.
[0028] The examples below are merely illustrative of this invention and are not intended to limit it thereby in any way.
EXAMPLE 1
[0029] In this example Pb and As contaminated soil (waste from Conoco Phillips operations) collected by URS personnel at soil remediation project in Weymouth, Mass., was stabilized with varying amounts of stabilizing agents including Magnesium Oxide (MgO), Cement Kiln Dust (CKD), ferric oxide powder (FP), DiCalcium Phosphate (DCP), Triple Superphosphate (TSP) and combinations thereof. Various stabilized and un-stabilized soil samples were subsequently tested for SPLP, TCLP, and MEP#10 soluble Pb and As and compared to project limitations for TCLP Pb and As of 5 ppm, and SPLP and MEP of 10 ppb Pb and 200 ppb As. Soil samples were extracted according to SPLP, TCLP, and MEP procedure set forth by the USEPA Method 1312, 1311 and 1320 respectively. The extract samples were digested and then analyzed by ICP USEPA Method 200.7.
[0000]
TABLE 1
MEP Pb/As
Stabilizer Dose (%)
SPLP Pb/As
TCLP Pb/As
(ppm)
0 (Baseline)
14/27
15/31
11/20
8 CKD + 0.5 FP + 1.0 DCP
<0.05/<0.05
<0.05/<0.05
<0.05/<0.05
8 CKD + 0.5 FP + 1.0 TSP
<0.05/13.1
<0.05/23
<0.05/2.4
8 MgO + 0.5 FP + 1.0 DCP
<0.05/0.30
0.1/0.15
0.30/1.60
[0030] The foregoing results in Table 1 readily established the operability of the present process to stabilize combined Pb and As thus reducing SPLP, TCLP and MEP leachability and bioavailability. Given the effectiveness of the stabilizing agents in causing combined heavy metals to stabilize as presented in the Table 1, it is believed that an amount of the stabilizing agents total combined equivalent weight to less than 7% of heavy metal bearing material or waste should be effective. It is also apparent from the Table 1 results that certain stabilizing agent combinations are more effective for stabilization of Pb and As than individual stabilizing agent methods.
[0031] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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This invention provides a method for chemical stabilization of combined Pb and As bearing materials, contaminated soils and wastes subject to acid and water leaching tests or leach conditions by addition of stabilizing agents such that the leaching potential is inhibited to desired levels. The resultant material or waste after stabilization is deemed suitable for on-site reuse, off-site reuse or disposal as RCRA non-hazardous waste.
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FIELD OF THE INVENTION
[0001] The present invention relates to a composite panel made from cementitious mortar with properties of transparency to light.
PRIOR ART
[0002] WO03097954 describes building blocks in material such as cementitious mortar through which optical fibres pass to allow the transmission of light from one side of the block to the other. In this way, it is possible to see the outline of objects placed at the back of the block, which is thus commonly defined transparent.
[0003] The optical fibres are placed as weft in meshes or special fabrics and thus inserted in castings of cementitious mortar within formworks to give obtain blocks of dimensions variable in relation to their final use. These blocks are then sawn to obtain plates or panels which subsequently undergo smoothing and polishing. Only after these operations is it possible to obtain the transparency effect described above.
[0004] However, this effect is influenced by the intensity of the incident light on the block. In fact, in relation to the luminous intensity of the light an angle of incidence is determined, for example already with an inclination of around 20° (for a panel thickness of around 3 cm), beyond which the transparency effect determined by transmission of light by the optical fibres decreases progressively, this forming an evident limitation of this technique.
[0005] There are other problems linked to the technique according to WO03097954, which is somewhat complex. In order to position the optical fibres, it is in fact necessary to provide a special fabric as backing to be inserted in consecutive layers in the formworks, alternated with layers of mortar; moreover, the further steps of sawing into thin plates and polishing are also required, which also lead to considerable risks of manufacturing scrap, especially if pieces of substantial dimensions are required, such as square plates of over one metre per side. Finally, it must be considered that only one type of surface finish can be obtained with this technique, which does not allow the appearance of the surface to be adapted to specific aesthetic and architectural requirements.
SUMMARY OF THE INVENTION
[0006] The object of the present invention is to solve the problems of prior art mentioned above. In particular, it is desirable to avoid additional manufacturing steps to simplify production, to avoid scrap and waste of material making it more economical, and to obtain the desired transparency effect also with respect to unfavourable angles of incident light, or light diffused by reflection having a more limited luminous intensity with respect to direct light.
[0007] To achieve these objects the present invention proposes a composite panel made from cementitious mortar, characterized in that a plurality of through openings pass throughout its thickness, said through openings being filled with a transparent to light material.
[0008] Said transparent to light material is preferably a plastic material.
[0009] This plastic material can be composed of: polyacrylates, epoxy resins or polycarbonates.
[0010] Alternatively, said transparent to light material can be glass or glass based.
[0011] In an embodiment of the invention, said transparent to light material is in the form of a preformed element which is housed in said opening.
[0012] In a different embodiment of the invention, said transparent to light material is in the form of an element formed in said opening, for example by casting.
[0013] The shape of the openings is variable within a wide range of geometries and the element of transparent to light material is also correspondingly variable: a preferred shape is that of a prism of rectangular cross section capable of housing a corresponding plate or sheet, preformed or obtained by casting.
[0014] In an embodiment of the invention said openings are intercalatedly lined up along parallel rows. Said openings are identified by the dimensions in length, height and depth. The height (h) of said openings necessarily matches the panel thickness, the length (L) of said openings preferably ranges between 0.5 and 100 mm, the thickness of said openings preferably ranges between 0.5 and 5 mm. Said openings are preferably arranged along parallel rows set apart from one another by a distance ranging between 0.3 and 0.5 times the length (L). In any case the minimum distance between two consecutive openings arranged on the same row must be no less than twice the maximum diameter of the aggregate present in said mortar.
[0015] The distance between two rows of parallel openings preferably ranges between 5 and 10 mm, and in any case must be no less than twice the maximum diameter of said aggregate.
[0016] For example, for a panel with dimensions of 0.5 m×1.0 m, a thickness of 5 cm and formed by cementitious mortar with a maximum aggregate diameter of 2 mm, assuming a length (L) of the openings of 40 mm, the distance between two consecutive openings arranged on the same row is 15 mm, while the distance between two consecutive parallel rows is 5 mm.
[0017] Preferably, said transparent to light material is treated with a coating having light reflection properties, for example a ceramic based acrylic emulsion or epoxy emulsion reflective paint to increase cohesion of the system.
[0018] Transport of light can be optimized through suitable surface means, such as a film, having light reflection characteristics and interposed between the transparent material and the opening in which it is housed.
[0019] The reflective film can, for example, be composed of a ceramic based reflective paint. The reflective film can be applied directly to the preformed elements of transparent material or, in the case of elements of transparent material obtained by casting, it can be applied to the walls of the openings before casting. The film can be applied with a spray technique on the preformed elements of transparent to light material or on the inner walls of the openings by forming the photoreflective film on cores used to form the openings. In this case the surface of the core must first be treated with suitable release agents in order to ensure adhesion of said photoreflective film to the surfaces of the opening and not the core. If said transparent to light material is in the form of a preformed element, such as a plate or sheet, obtained by cutting a plate of greater dimensions, the cut must be performed with techniques which ensure a roughness of the cut surface which does not limit optical transmission. Laser cutting is, for example, suitable for this purpose.
[0020] The present invention also relates to methods for forming said panel. In a first embodiment, a method for producing a panel comprises the steps of:
a) positioning in an orderly arrangement within a formwork a plurality of elements of said transparent to light material; b) filling said formwork with said cementitious mortar until said plurality of elements of transparent to light material appears completely buried in it without contacting with said mortar the opposite sides of said elements, suitable to form the inlet and the outlet of said opening; c) hardening said mortar setting free said opposite sides of said elements of transparent to light material, suitable to form the inlet and the outlet of said opening, and taking out the finished panel from the formwork.
[0024] In a second different embodiment, a method for producing a panel comprises the steps of:
d) filling a formwork with said cementitious mortar positioning in an orderly arrangement within said formwork a plurality of cores, preferably coated with release agent and photoreflective film, suitable to form said openings until said plurality of cores appears completely buried in said mortar without contacting the opposite sides of said cores, suitable to form the inlet and the outlet of said opening, with said mortar; e) during the time period from the beginning to the end of the mortar setting, taking out said cores from said formwork setting free said thus formed openings; f) if the cores were not coated with reflective film, the further step of coating the inside of said openings with a reflective paint, for example using spray methods; g) filling said openings with said fluid state transparent to light material; h) allowing the mortar and the transparent to light material to harden to afford said panel, and taking out the finished panel from the formwork; i) allowing the panel to rest until it has hardened.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to better understand the characteristics and advantages of the invention, non-limiting practical examples of embodiment are described below with reference to the figures of the accompanying drawings.
[0032] FIG. 1 shows a partial perspective view of a panel according to the invention.
[0033] FIG. 2 shows a cross sectional view according to the line II-II of FIG. 1 , partial and enlarged.
[0034] FIG. 3 shows a cross sectional view according to the line III-III of FIG. 1 , partial and enlarged.
[0035] FIG. 4 schematically shows a perspective view of a step of one of the methods for producing the panel of FIG. 1 .
[0036] FIG. 5 shows a cross sectional view, identical to that of FIG. 3 , of a variant of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] With reference to FIGS. 1 to 4 , a plurality of through openings 11 , each containing a transparent to light material, pass throughout the thickness of a concrete panel 10 , formed by cementitious mortar as described with regard to FIG. 4 .
[0038] In the example, said transparent to light material is in the form of a plurality of elements formed by plates 12 made of PMMA, preformed and housed in said openings using the forming method described below with reference to FIG. 4 . In the example shown, said openings are intercalatedly lined up along parallel rows 16 .
[0039] With reference to FIG. 4 , a formwork 13 was prepared by wholly coating the bottom 14 with a layer of compressible material, compatible with mortar and PMMA, such as non woven fabric, in order to prevent reflux and adhesion of the mortar to the section of the transparent plates. Said compressible material can be coated with a suitable layer of material with defined weft, such as a fabric, in order to obtain a finish with corresponding surface textures.
[0040] A plurality of elements of said transparent to light material in the form of plates 12 are positioned in an orderly arrangement within a formwork, according to parallel rows 16 using a frame formed by parallel movable rods 15 which can thus clamp the rows 16 of plates 12 , lined up and spaced with templates, to hold them firmly in position.
[0041] The PMMA plates are obtained, for example, by laser cutting from plates of commercial sizes.
[0042] The frame is arranged so that the perimeter 17 of the formwork is left free of plates 12 so as to define a corresponding empty perimeter edge within it.
[0043] The formwork is then filled with cementitious mortar pouring it through the perimeter edge 17 left free of plates, until said plurality of plates 12 of transparent to light material appears completely buried in it without contacting with said mortar the opposite sides 19 and 20 of the plates 12 , which thus remain free for their function. This is made possible for the side of the plate facing the bottom of the formwork through an action of pressure against this bottom on the non woven fabric, which thus produces a seal so as to prevent infiltration of mortar between the plates in that area. For the opposite side, the level of poured mortar will at the most reach the surface of this side of the plate.
[0044] The mortar is then left to harden, setting free said opposite sides 19 and 20 of the plates 12 suitable to form the inlet and the outlet of said corresponding opening 11 which thus remains identified in the formed panel, and the finished panel 10 is taken out of the formwork.
[0045] In order to strengthen the composite structure, in other embodiments a reinforcement is placed along the edges of the panel, or a metal lath, with mesh openings suitable not to interfere with the plates already positioned, can be laid.
[0046] In a further embodiment of the invention as shown in FIG. 5 , said through openings are such that said transparent to light material that fills them is formed according to a single element 12 which extends continuously for a complete dimension, for example the height, of the panel 10 . The dimension (h) of 12 in FIG. 5 matches the thickness of the panel 10 while h 0 ≦0.2 h matches a thinner section 21 of the element 12 which identifies an interspace suitable to be filled with mortar during forming of the panel.
[0047] Also in this case, in a first embodiment of the variant said transparent to light material is in the form of a preformed element, for example by laser cutting of plates of commercial sizes, which is housed in a corresponding opening. In a second embodiment of the variant, said transparent to light material is an element formed in said opening, for example by casting in specific moulds.
[0048] The elements 12 according to the variant of FIG. 5 , which are configured according to a sort of continuous chain of plates, are housed in formworks whose shorter opposite sides are comb-shaped in order to perform the function of template. These chains of plates can also be tensioned with the use of suitable means.
[0049] All cements described by the standard UNI-EN 197.1 can be used in the mortar for the purposes of the present invention. Preferably, type I cement in class 52.5R will be used.
[0050] The setting time of the cement becomes important in particular when using the method of preforming the openings through a suitable counter mould.
[0051] The time period for the beginning of setting can be regulated, for example by adding small quantities, no greater than 10% in mass with respect to the cement, of a sulfoaluminate binder. In a preferred aspect of the invention the sulfoaluminate binder marketed with the trade name ALIPRE by Italcementi is used.
[0052] The calcareous filler can be of any type, although the air separated type, i.e. obtained with an air classifier, is preferably used for the present invention.
[0053] The maximum diameter ranges between 60 and 70 μm, preferably 63 μm.
[0054] The aggregates can be of any nature, in conformity with the standard UNI EN 12620. The maximum diameter is influenced by the minimum distance between openings and can range between 1.5 and 5 mm, preferably 2 mm.
Example
[0055] The method described above is implemented with reference to the accompanying drawings, or the alternative forming method also described above, using cementitious mortar of the high fluidity and shrinkage-compensated type, having the following composition:
[0000]
Values chosen
in the
field
example
CEM | 52.5R + 5% of
420-520 kg/m 3
470 kg/m 3
sulfoaluminate
Air separated calcareous
230-330 kg/m 3
280 kg/m 3
filler
Aggregate (max. diameter
1300-1400 kg/m 3
1315 kg/m 3
2 mm)
w/c ratio
0.45-0.55
0.5
Superfluidifying additive
According to
According to
the technical
the technical
data sheet
data sheet
Shrinkage Reducing
According to
According to
Admixture (SRA)
the technical
the technical
data sheet
data sheet
Expansive admixture
According to
According to
the technical
the technical
data sheet
data sheet
Polymer fibres to prevent
1 kg/m 3
1 kg/m 3
cracking in the plastic
phase
[0056] As can be understood from the description and example indicated above, the panel produced according to the present invention is capable of achieving all the objects initially proposed: in particular, it is possible to avoid additional manufacturing steps, simplifying production, to avoid scrap and waste of material, and to obtain the desired transparency effect also with respect to unfavourable angles of incident light, or light diffused by reflection having a more limited luminous intensity with respect to direct light. This improved effect is apparent by comparing the aforesaid prior art panel with the panel of the invention with the same angle of incidence of the light beam.
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The present invention relates to a composite panel made from cementitious mortar characterized in that a plurality of openings pass through its complete width, each of which is filled with a transparent to light material. The invention also relates to methods for producing this panel.
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BACKGROUND OF THE INVENTION
Shuffle feed apparatus utilize parallel-positioned feed members which are reciprocated back and forth in opposite directions in a wave action to move articles in single file order along their leading edges. For the most part such feed mechanisms are used in the handling of small items, such as fruits and vegetable food products to control the feed rate to a processing station. Because of their use in the food processing industry, it is important that such apparatus be readily cleanable. in addition, it is important that the apparatus operate in a manner to prevent, to the degree possible, the access of the product between flights because of the loss of the product as well as the contamination of the apparatus.
When the articles being handled do fall between the individual flights, jamming and malfunction of the apparatus can result. Such is particularly true in the handling of solid articles such as nuts and bolts or the like made of metal. As a result the flights must be precision manufactured so as to move along paths spaced closely together which can increase substantially the cost of manufacture of the apparatus. In addition the closely positioned parts can cause greater friction and require more power to operate than other apparatus.
The primary purpose of this invention is to provide a shuffle feed mechanism of relatively simple design which will handle articles having a small diameter and in particular, elongated articles having a small diameter.
CROSS-REFERENCE TO RELATED PATENTS
Application for United States Patent, Ser. No. 777,559, Shuffle Feed Structure, Chester Green, Filed Mar. 14, 1977, now abandoned.
SUMMARY OF THE INVENTION
A shuffle feed apparatus having two sets of shuffle feed members supported by corresponding frame members for reciprocal movement to move articles in single-file order along their leading edges. The adjacent flights include overlapping portions so as to present overlapping leading edges to prevent alignment of articles on the front faces thereof with the space between flights.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a shuffle feed mechanism of the type in which the subject invention can be incorporated;
FIG. 2 is an end view of the apparatus of FIG. 1;
FIG. 3 shows the various positions of the frame members in reduced size during operation of the shuffle feed apparatus;
FIG. 4 is an enlarged partial view in perspective of the shuffle feed flights of FIG. 1;
FIGS. 5A and 5B are side views of the flights in the various positions for advancing articles along the leading edges thereof;
FIG. 6 is a perspective view of a portion of the flights incorporating the subject invention;
FIG. 7 is an end view of two adjacent flights incorporating the subject invention; and
FIG. 8 is a side view showing the manner in which the adjacent flights overlap.
DESCRIPTION OF THE INVENTION
The invention is embodied in a shuffle feed apparatus such as that shown in FIGS. 1 and 2 comprising a shuffle feed bed 10 having similar movable sets of independently supported and alternately arranged shuffle members 11 and 12. These members usually are fabricated from sheet metal or from a molded material and are mounted in an inclined position each having upwardly facing article-supporting faces 14 and 15, respectively. By reciprocatory movement of the sets of members relative to each other and along parallel paths, articles 16 (FIGS. 5A and 5B) can be moved forward in single-file order. The overall object of a shuffle feeder is to move the articles aligning with the front faces of the shuffle members forward while permitting the articles not aligning with each front face, i.e. piled on top, to slide back along the side of the advancing shuffle feed member so as not to be progressed forward. By the time articles reach the end of the shuffle apparatus, they are being advanced along lines by the valley-to-valley wave action of the shuffle apparatus at a controlled feed rate.
As shown in FIGS. 5A and 5B, the shuffle members 11 and 12 are reciprocated along paths parallel to each other so the article is alternately pushed up the side of the next shuffle feed member by the face of the last and adjacent shuffle feed member. The sizes of the faces of the shuffle feed members and at times the shapes of the faces are adapted to accommodate different configurations of articles to be fed. The different flights of shuffle feed members 11 and 12 are fixed to pairs of parallel-positioned side frame members 17 and 18, respectively. The side frame members 17 are parallel-positioned and inside the parallel-positioned side frame members 18 as shown primarily in FIG. 2. The shuffle feed members preferably are welded to the respective side frame members and positioned in spaced parallel relationship in an inclined position so that the trailing feed member will advance an article up the side of the next feed member and allow it to drop down in front of the front edge of that next member.
Each frame member 17 includes a plurality of slots (FIG. 4) aligned with the space between and extending in a direction parallel to the flat sides of the attached shuffle members 11. Each shuffle member 12 includes an end-mounted extension 20 sized to fit through the slot 19 in the adjacent side frame member 17 for attachment to the frame member 18. The shuffle members thus are interspersed between each adjacent pair of shuffle members and can be shifted within the slots 19 to provide the shuffle feed action. As a result a compact structure wherein the side frame members are positioned adjacent to one another in side-by-side relationship is provided.
The shuffle feed bed 10 is supported on a support and drive apparatus in a manner to be easily removed for cleaning and interchanging. As shown primarily in FIGS. 1, 2 and 3, there is positioned beneath the shuffle feed bed a center support 21 and a pair of side rails 22 for attachment to the side frame members 17 and 18, respectively. The center support 21 is fixed to the cross support 24 connecting the spaced side frame members 17 in a suitable manner such as by bolting. Similarly the side supports 22 are fixed to the side frame members 18 by a suitable manner such as by the fasteners 25 shown in FIG. 1.
For support and movement of the shuffle feed members back and forth, the center support 21 and side supports 22 are mounted respectively on upright posts which are pivoted back and forth by a suitable drive means. For instance, the center support 21 is fixed to the ends of the parallel-positioned and spaced uprights 26 by bolts 27 passing through the upper ends of the upright supports and the flanges 28 fixed to the center support. Also, the flanges 22 are supported on four uprights 30 by bolts 31 passing through flanges on the supports 22.
The apparatus is supported on the upright legs 32 supporting a pair of parallel-spaced intermediate beams 34. Extending between these beams are a pair of shafts 35 positioned to pass through aligned openings in the adjacent uprights 26 and 30 at each end of the apparatus. The shafts pass through the uprights at an intermediate position such that pivoting of the uprights about the shafts will cause a reciprocatory motion of the supported side frame members and the attached flight members.
The lower ends of the uprights are oscillated back and forth by an eccentric drive apparatus 33. Connected to a shaft 26A extending between one pair of the uprights 26 is a drive link 36 riding on one land 37 of an eccentric 38. Similarly a drive link 39 is pivotally attached to a shaft 30A connecting lower ends of the pair of uprights 30 is driven by a land of an eccentric 40. The lands are driven by a shaft 42 which is power driven by a suitable means (not shown) such that by rotation of the eccentrics 38 and 40 the uprights 26 and 30 are reciprocated back and forth in an alternating fashion to move the shuffle flights back and forth for advancing articles resting on the front edges or faces of the flight members in the manner previously described.
Frequently, such shuffle feeders are utilized to align and singulate elongated articles such as bread sticks, carrots, spaghetti, jerky, bolts, ball point pens and the like. The reason for this widespread usage is that such articles must be aligned when packaged because they cannot be randomly placed in a container suitable for shipment or retail sale. Thus, alignment and singulating is necessary to permit the counting of the individual articles and the subsequent packaging in a parallel aligned manner.
However, such articles frequently are of small diameter even though long, making them susceptible to falling or wedging between the individual flights of a shuffle feeder. As explained before, such shuffle feed flights frequently are spaced apart slightly because of the relative motion and this spacing can be sufficient to permit small articles being handled to wedge between the flight members. It is the primary purpose of the subject invention to provide an apparatus which will feed such articles in a controlled manner and yet prevent such articles from passing between flight members.
In accordance with the present invention, the flight members are constructed with the adjacent complementary surfaces including offset portions such that the space between flights is not planar. The offset portions are spaced apart a distance less than the normal length of the articles being handled such that the articles always abut a portion of the face of the next preceding flight. In this manner the articles are prevented from passing between flights even if the diameter is sufficiently small to possibly wedge therebetween.
Accordingly, as shown primarily in FIG. 7, the flight member 11 includes offset portions 44 and included grooved areas 45 which are complementary to the offset or projecting areas 46 of flight 12 and the included grooved areas 47, respectively. These grooves and projecting areas have sides extending parallel to the direction of travel of the flight members. In this example the offset portions have sides facing normal to the direction of travel of the shuffle feed members. Thus, movement of the flight members is not encumbered as is illustrated in FIG. 8.
To explain the operation of the flight members in the advancing of articles, the articles 16 (FIG. 7) have a length L exceeding the width A of the grooves and projections. Thus, as illustrated the article 16A in being advanced will extend past one of the projections 44 as it abuts the front face of the flight 11 such that at least one end rests on the adjacent projection 46 on the top surface of the flight 12. Thus, as described there is provided a means for handling elongated articles of small diameters even though the space between flights might be close in size to the diameter of the articles. Of course it is usually advantageous to make the spacing between flights as small as possible in comparison to the diameter of the articles being handled within the limits of economical manufacture and operation of the apparatus.
While a particular configuration of the flights is illustrated in FIGS. 6, 7 and 8, it should be understood that the offset portions can be any of a multitude of configurations which make the offset portions between flights closer spaced than the length of the articles being handled. In this manner the articles are kept out of alignment with the flight junctures so long as they are resting flat against the flight faces.
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A shuffle feed structure comprising first and second sets of shuffle feed mbers supported on their respective frames for reciprocating movement so as to advance articles lying thereon in single file order. The feed members are constructed with adjacent surfaces including offset portions so as to prevent articles being advanced from aligning with and falling through the space between the individual flights.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods of automatically setting document registration and locating a calibration strip in an image inputting machine, and in particular to methods of automatically setting document registration and locating a calibration strip in an image inputting machine which includes an electronic scanner for reading data from a document and transforming that data into digital signals which can be stored and/or analyzed.
2. Description of Related Art
Traditionally, Universal Document Handlers (UDH) used with copiers or image inputting machines require mechanical adjustment of mirrors, scan carriage assemblies, or other assemblies to adjust document registration. One such mechanical adjustment involves setting the document registration so that the scan carriage which inputs data contained on the documents begins its scanning traversal of the document at an edge of the document. Another adjustment, required with electronic scanners, involves location of a calibration strip which is used to calibrate the Charge Coupled Devices (CCD) which typically make up the scanning array.
Difficulties in automatic document handling systems in general are discussed hereinbelow. These difficulties include the criticality of document registration and the need for increased automation and operator simplification especially with current increases in document handling speeds.
As xerographic and other copiers increase in speed, and become more automatic, it is increasingly important to provide higher speed yet more reliable and more automatic handling of the document sheets being copied, i.e. the input to the copier. It is desirable to feed, accurately register, and copy document sheets of a variety or mixture of sizes, types, weights, materials, conditions and susceptibility to damage, yet with minimal document jamming, wear or damage by the document transporting and registration apparatus, even if the same documents are automatically fed and registered repeatedly, as for recirculating document precollation copying.
The art of original document sheet handling for copiers has been intensively pursued in recent years. Various systems have been provided for automatic or semiautomatic feeding of document sheets to and over the imaging station of the copier for copying. The documents are normally fed over the surface of an imaging station comprising a transparent platen, into a registered copying position on the platen, and then off the platen. Such automatic or semiautomatic document handlers eliminate the need for the operator to place and align each document on the platen by hand. This is a highly desirable feature for copiers. Document handlers can automatically feed documents as fast as they can be copied, which cannot be done manually with higher speed copiers, thus enabling the full utilization or productivity of higher speed copiers.
A preferable document handling system is one that utilizes an existing or generally conventional copier optical imaging system, including the external transparent copying window (known as the platen or imaging station) of the copier. It is also desirable that the document handling system be readily removable, as by pivoting away, to alternatively allow the copier operator to conventionally manually place documents, including books, on the same copying platen. Thus, it is desirable that a document registration edge alignment or positioning system be available for such manual copying which is compatible with that used for the document handler.
One of the most difficult to achieve features for automatic document handling is the rapid, accurate, reliable, and safe registration of each document at the proper position for copying. Conventionally the document is desirably either center registered or corner registered (depending on the copier) by the document handler automatically at a preset registration position relative to the copier platen. At this registration position, two orthogonal edges of the document are aligned with two physical or positional (imaginary) registration lines of the copier platen at which the original document is properly aligned with the copier optics and copy sheet/photoreceptor registration system for correct image transfer of the document image to the photoreceptor and then to the copy sheet. This registration accuracy is desirably consistently within approximately one millimeter. If the document is not properly registered, then undesirable dark borders and/or edge shadow images may appear on the ensuing copy sheet, or information near an edge of the document may be lost, i.e. not copied onto the copy sheet. Document misregistration, especially skewing, can also adversely affect further feeding and/or restacking of the documents.
In preferred types of copying systems the document is registered for copying overlying a selected portion of a full sized (full frame) platen which is at least as large as the largest document to be normally copied automatically. In such systems the document is preferably either scanned or flashed while it is held stationary on the platen in the desired registration position. That is, in these full frame systems the document is preferably registered by being stopped and held during imaging at a preset position over the platen glass which is adjacent one side or edge thereof.
As shown in the art, and further discussed below, document handling systems have been provided with various document transports to move the documents over the copier platen and into registration. Such document platen transports may comprise single or plural transport belts or feed wheels, utilizing frictional, vacuum, or electrostatic sheet driving forces. Various combinations of such transports are known with various registration devices or systems. Preferably the same platen transport sheet feeder is used to drive a document onto and off of the platen before and after copying as well as registering the document.
The present invention is particularly suitable for precollation copying, i.e. automatically plurally recirculated document set copying provided by a recirculating document handling system or "RDH". However, it also has applicability to nonprecollation, or postcollation, copying, such as postcollation operation of an RDH or semiautomatic document handling (SADH). Postcollation copying, or even manual document placement, is desirable in certain copying situations, even with an RDH, to minimize document handling, particularly for delicate, valuable, thick or irregular documents, or for a very large number of copy sets. Thus, it is desirable that a document handler for a precollation copying system be compatible with, and alternatively usable for, post collation and manual copying as well.
Some examples of Xerox Corporation RDH U.S. Patents are U.S. Pat. No. 4,459,013 issued July 10, 1984 to T. J. Hamlin et al; U.S. Pat. No. 4,278,344 issued July 14, 1981 to R. B. Sahay; and U.S. Pat. Nos. 4,579,444, , 325 or 326. Some other examples of recirculating document handlers are disclosed in U.S. Pat. Nos. 4,076,408; 4,176,945; 4,428,667; 4,330,197; 4,466,733 and 4,544,148. A preferred vacuum corrugating feeder air knife, and a tray, for an RDH, are disclosed in U.S. Pat. Nos. 4,418,905 and 4,462,586. An integral semiautomatic and computer form feeder (SADH/CFF), which may be an integral part of an RDH, as noted in col. 2, paragraph 2, therein, is disclosed in U.S. Pat. No. 4,462,527. Various others of these patents, such as U.S. Pat. No. 4,176,945 above, issued Dec. 4, 1979 to R. Holzhauser (Kodak) teach plural mode, e.g. RDH/SADH, document handlers.
Regardless of the type of document handler used, or whether any document handler is used, the scan carriage must be properly aligned with the registration positions of documents on the platen. This alignment has been done in the past by determining the amount of adjustment needed to compensate for misalignment between the registration position to which a document is positioned (either manually or by a document handler) and the scan carriage start position, and manually adjusting either the scan carriage (or copier) or the document handler so that the registration position of the document and the initial scan carriage position are aligned. Since it is desirable to use a type of document handler that includes structure for feeding documents automatically from an RDH input and semiautomatically from an SADH input, (the SADH input also being capable of receiving computer fan folds (CFF)) which document handler locates sheets at different positions on the platen depending on whether the sheets are fed from the RDH or SADH inputs, up to three separate adjustments must be made in order to align the scan carriage with the registration positions of documents
Additionally, since it is desirable to use a document handler which is compatible with a variety of different copying machines or input scanners (known as universal document handlers (UDH)), it is desirable to provide an input scanner which can adjust itself to the document registration positions of the UDH so that production tolerance in the manufacture of the UDH and input scanner need not be coordinated with each other with high tolerances. It is also desirable to provide a system for registering a document scanner to sheets placed on a platen which does not require every sheet to be prescanned since prescanning slows down the throughput of the scanner.
U.S. Pat. No. 4,831,420 to Walsh et al. discloses a system for setting or adjusting the proper registration position of the original documents in a copier having a document feeder providing a variable document registration position on the platen, and numeric data key entries in specialized diagnostic modes, and non-volatile memory. The system involves registering and copying a test sheet using the document feeder in its initial, unadjusted, registration setting. The test sheet has a test pattern of registration position indicia with identifying numeric indicia, and also includes a registration window at an optically reversed position on the test sheet from the test pattern and a cursor pointing to a specific position within the window. The test sheet is laid over a same-size copy of the test sheet, with the sheet edges aligned, but with the two sheets rotated by 180° relative to one another, so that the copy of the test pattern on the copy sheet underlies and is visible through the registration window of the test sheet, whereby the cursor on the test sheet points to a specific registration identifying numeric indicia within the test pattern copy. The copier resets in non-volatile memory the registration position of the document feeder based upon an operator entering the identifying numeric indicia into the numeric data key entries of the copier.
U.S. Pat. No. 4,724,330 to Tuhro, assigned to Xerox Corporation, discloses a system which includes a raster input scanning device including a linear photoelectric sensor array and a movable carriage for moving an aperture card which contains information across the scanning array. The aperture card includes a target which is used by the scanning device to calculate Y-axis and X-axis offset values representative of the distances in the Y and X directions which the information on the aperture card differs from a predetermined location The offset values are used to discard data inputted from portions of the aperture card which do not contain any information.
A publication entitled "7650 Pro Imager IBM PC Compatible Service Manual", published April 1989, discloses on page 4-3 registration and skew adjustment of a document handler to a copying machine which utilizes a test document having a black edge. It appears as if the registration is manually adjusted.
U.S. Pat. No. 4,711,552 to Nilsson discloses an electrophotographic copier which synchronizes copy sheet gating, optic start of scan and document conveyor registration The start of scan of the optics assembly is effected by positioning a test master document having dark portions adjacent its leading and trailing edges on the platen, making a copy of the test master document, determining the length of undeveloped area adjacent to the leading edge of the copy, and adjusting the start of scan as a function of the determined length. These steps are done by visual inspection or by an optical sensor which is located downstream of the toner fixing station. The adjusting may be done electronically or mechanically.
U.S. Pat. No. 4,864,415 to Beikirch et al., assigned to Xerox Corporation, discloses a system for self-aligning a raster input scanner in a slow scan direction. The carriage is moved in the scan direction until sensed by a limit switch. Upon detection of the carriage by the limit switch, the carriage motion is reversed and the carriage is moved in the pre-scan direction over a target. The target, having a variable density image, is scanned until a preset target image line is obtained and the scan carriage position is registered. From this position, the carriage continues moving in the pre-scan direction until the length of the platen is scanned a predetermined number of scan lines. Then the carriage is reversed and moved in the scan direction to scan a document. Movement continues until the predetermined number of scan lines is counted at which time the image signals from the target are compared with the registration reference image. If a difference is detected, a fault flag is set. This procedure is carried out for every sheet to be copied and thus greatly decreases the efficiency of the machine.
U.S. Pat. No. 4,511,242 to Ashbee et al. discloses an electronic alignment of paper feeding components in a electrophotographic copier machine. Alignment is accomplished by placing an original master containing vernie calibrations on the document glass and a target master containing vernier calibrations in a copier paper bin. The machine is operated to produce a copy of the original master onto the target master to produce a double set of calibrations on the target master. When prepared, the copy provides information relating to skew angle, side edge registration and lead edge alignment of the image to the copy paper. This information is used to manually adjust the copier. Sensors are located in the copy paper path to automatically correct for deviations by calculating an average correction needed after a predetermined number of copies are made. This device compensates for the location of an original on a glass platen by adjusting the positioning of the receiving sheet relative to a photoreceptor drum.
U.S. Pat. No. 4,605,970 to Hawkins discloses a method and apparatus for calibrating an optical document digitizer.
U.S. Pat. No. 4,647,981 to Froelich, assigned to Xerox Corporation, discloses an automatic white level control for a raster input scanner. A circuit is provided to add a correction based on a predetermined correction curve for determining the amount of deviation of a light level from a desired level.
The disclosed apparatus may be readily operated and controlled in a conventional manner with conventional control systems. Some additional examples of control systems for various prior art copiers with document handlers, including sheet detecting switches, sensors, etc., are disclosed in U.S. Pat. Nos.: 4,054,380; 4,062,061; 4,076,408; 4,078,787; 4,099,860; 4,125,325; 4,132,401; 4,144,550; 4,158,500; 4,176,945; 4,179,215; 4,229,101; 4,278,344; 4,284,270, and 4,475,156. It is well known in general, and preferable, to program and execute such control functions and logic with conventional software instructions for conventional microprocessors This is taught by the above and other patents and various commercial copiers. Such software will of course vary depending on the particular function and the particular software system and the particular microprocessor or microcomputer system being utilized, but will be available to or readily programmable by those skilled in the applicable arts without undue experimentation from either verbal functional descriptions, such as those provided herein, or prior knowledge of those functions which are conventional, together with general knowledge in the software and computer arts. Controls may alternatively be provided utilizing various other known or suitable hard-wired logic or switching systems.
All references cited in this specification, and their references, are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features, and/or technical background.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an input scanner which can automatically register its scan carriage to objects in its path.
It is another object of the present invention to provide an input scanner which automatically adjusts itself so that the scan carriage begins scanning at the leading edge of a document.
It is a further object of the present invention to provide an input scanner which automatically locates the position of a calibration strip.
To achieve the foregoing and other objects, and to overcome the shortcomings discussed above, a method of locating the position of an object on the platen of a raster input scanner having a movable scan carriage and an extended array of scanners is disclosed. The method includes the steps of obtaining a previously stored theoretical position of the object from a memory, locating the scan carriage at a position spaced a predetermined distance from the previously stored position, moving the scan carriage toward the previously stored position while operating at least some of the scanners until a target on the object is detected by the operating scanners, and storing a target position of the scan carriage where the target is detected. The target position can represent, for example, the location of the scanner's calibration strip or the registration position of a document. After the target position is stored, the scan carriage can be located at the target position for calibrating the scanners if the target position represents the location of the calibration strip. Alternatively, the scan carriage can be located at the target position prior to actuating the scanners for each subsequent document to be scanned if the target position represents a document registration position. This procedure is repeated to determine the document registration positions for documents which are placed on the platen manually, by an SADH or SALDH input, by a CFF input, or by an RDH input.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein:
FIG. 1 is a schematic side view of an RDH/SADH document handler and electronic image scanner usable with the present invention;
FIG. 2 is a schematic side view of an image scanner which utilizes a movable scan carriage and a fixed array of scanners;
FIG. 3 is a plan view of the transparent platen of a document scanner illustrating the positions of sheets on the platen when placed thereon either manually, by an RDH or by an SADH;
FIG. 4 illustrates a sheet containing a test pattern usable with the present invention;
FIG. 5 is a schematic plan view illustrating the movement of a scan carriage for registering the scan carriage to a sheet placed on a transparent platen; and
FIG. 6 illustrates a display outputted on a monitor when operating a document scanner in the registration mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of illustration, in FIG. 1, a universal document handler (UDH) 20 is illustrated in association with an image scanning system 10. The universal document handler 20 can be similar to that disclosed in copending U.S. patent application Ser. No. 07/559,020 to James R. Graves et al and entitled "SCANNER DOCUMENT ABSENCE CODE SYSTEM" filed July 27, 1990 the disclosure of which is herein incorporated by reference. The image scanning system 10 includes an array of scanners 11, for example, Charge Coupled Devices, mounted on a movable scan carriage 40 which traverses along beneath a transpent platen 30 from one end 30a to another end 30b thereof. A number of mirrors and a lens are provided to focus and condense the light image reflected from the original document onto the array of scanners since the array of scanners 11 is much smaller than the width of platen 30 as is well known in the art. The image scanning system 10 is also operatively connected to a monitor 50 for monitoring the data inputted by the scanner as well as for outputting information on its screen for use by operators of the scanner to be described below.
Universal document handler 20 is pivotally attached to an upper surface of the image scanning system by hinges 32 (see FIG. 2) so that the UDH can be lifted off of platen 30 for manually placing documents on platen 30. UDH 20 also includes a top or RDH stacking tray 21 for receiving sheets to be fed to platen 30 and read by scanning system 10 in a recirculating fashion. An SADH/CFF input slot 22 is also provided for inputting sheets or computer forms in a semiautomatic fashion. UDH 20 also operates in an SALDH mode, whereby long sheets (e.g., have a length greater than 12 inches) are inputted at slot 22 and located on platen 30. After passing through appropriate sets of drive rollers, the document is fed across platen 30 by a transport belt 24. As described earlier, transport belt 24 momentarily stops the sheets on platen 30 so that they can be read by scanner array 11. Sheets exit platen 30 at outlet 31 and are either returned to RDH stacking tray 21 or outputted to an output tray. The operation of UDH 20 is controlled by controller 100.
FIG. 2 is a side schematic view of an image scanner which includes a movable carriage 40 and a scanner array 11 which is fixedly mounted within the frame of the document scanner. Thus, unlike the embodiment shown in FIG. 1, scanner array 11 does not move with scan carriage 40. The optical system includes a stationary glass platen 30 on which an original document to be reproduced is located for copying. The original document is illuminated in known manner a narrow strip at a time by a light source comprising, for example, a tungsten halogen lamp 44. Light from the lamp is concentrated by an elliptical reflector 42 and directed to the platen and to an inclined mirror 45. The two light components combine to form a narrow strip of light at the side of the original document facing the platen 30. The original document thus exposed is imaged onto a scanner array 11 via system of mirrors M1 to M3 and focusing lens 48. In order to copy the whole original document, the lamp 44, the reflector 42, and mirror 45 are mounted on full rate carriage 40 which travels laterally at a given speed directly below the platen and thereby scans the whole document. Because of the folded optical path, the mirrors M2 and M3 are mounted on another carriage 46 which travels laterally at half the speed of the full rate carriage in order to maintain the optical path constant.
FIG. 3 illustrates the different positions where a sheet will be located on platen 30. A sheet will be located at position A when it is manually placed on platen 30, whereas the sheet will be located at position B when fed by SADH (i.e., inserted into input 22) and located at position C when inputted from stacking tray 21 and fed by RDH. When operating in SALDH mode, a sheet is located between positions B and C. The present invention properly registers the start position of scan carriage 40 to the actual location of the sheet on the platen for each mode of operation of the device by using the CCD's of the scanner array 11 to determine where the sheet is located on platen 30 when placed there either manually, by the RDH, by the SADH, or by the SALDH. The registration position for CFF can be determined from the SADH registration position. The registration position of a sheet for each mode of feeding is determined by placing a test document containing a test pattern or target thereon which can be detected by the CCD's of the scanner array 11. In particular, the test pattern is used to locate the edges of the test document by moving scan carriage 40 in the slow scan direction (that is, the direction in which scan carriage moves) to detect the location of a trailing side edge of the sheet (SS1, SS2, and SS3 for sheets A, B, C and the SALDH position between B and C respectively). Once the trailing side edge of the sheet is located, scan carriage 40 is moved to two different positions wherein the scan carriage extends across the sheet, the scan carriage is stopped in each position and all of the scanners in the scanning array 11 are actuated to detect the top and bottom edges of the sheet at two different locations. This is known as fast scanning and is performed on each sheet, for example at points FS1, FS2 and FS3 for each of sheets A, B and C, respectively.
The information obtained by the scanner array is then utilized in a manner to be described below to automatically set the scan carriage to begin scanning documents at the location of the trailing side edge as determined by the slow scan. By starting carriage 40 at the exact location of the sheet, the movement required by carriage 40 is reduced, thus increasing throughput, and data which contains no information (i.e., from portions of the platen not covered by the document) does not have to be analyzed and discarded as in previous systems. Additionally, only the scanners of the scanning array necessary to input all the information from each sheet are actuated (as determined by the fast scan operation) so that data from scanners located over areas of the platen 30 which do not contain the sheet is not inputted or analyzed.
The top, bottom and side edges of each sheet are detected by running a test sheet over platen 30 which contains a test pattern thereon through the RDH, SADH and SALDH modes as well as the manual mode of the device. The test sheet could be entirely black so that the ability of the scanners on the scanner carriage 40 to detect the transition from black to white which occurs at the edges of the test sheet which is covered by a white platen cover is utilized to detect the lead and side edges of a sheet.
Preferably, the test sheet includes a test pattern as illustrated in FIG. 4. The black to white transition is still utilized, however the entire sheet is not made black. Test sheet 110 includes a trailing side edge 111 which is the edge of the sheet used when scanning in the slow scan direction. Instead of scanning for the trailing edge of the sheet with all of the scanners in the scanning array 11, it is preferable to use two scanners in the array which are spaced from each other so that the input skew of the document can also be determined. Thus, only two darkened areas 112 and 114 are provided on the trailing side edge 111 of the test sheet 110 for detection by the two spaced apart scanners in the scanning array 11. These patterns 112 and 114 can be located, for example, at distances which are two inches and seven inches, respectively, from a bottom edge of the sheet. If the test document 110 is skewed, the test patterns 112 and 114 will be detected at two different locations relative to the slow scan direction. The average of the two locations is used as the location of the trailing side edge of the document. The system software can analyze the data inputted from the active scanners to output information on monitor 50 so that an operator can determine whether adjustment for side-to-side skew is necessary (see FIG. 6). While the present invention automatically registers the scan carriage to the document position, it does not automatically adjust for skew.
The test document 110 also includes patterns 116 spaced apart along the bottom edge thereof for use during the fast scan process. The position of the bottom edge of sheet 110 is determined at two locations by detecting patterns 116. The location of the top edge is calculated since the height of the sheet is known. Any differences in the locations of the bottom edge of the sheet relative to the fast scan direction also indicates a skew problem. For example, even if there is no detected skew in the slow scan direction, skew can exist in the fast scan direction if the scanning array is misaligned. The system software can also analyze data inputted from the scanners when located at the two fast scan locations to output information to monitor 50 regarding top-to-bottom skew. Thus, only the trailing side edge 111 and the bottom edge of the test document needs to be precisely formed and made perpendicular to each other with a high degree of accuracy since the locations of the other edges of the test document are calculated based upon the known size of the sheet. Since the trailing side edge and bottom edge of each sheet placed on platen 30 are placed in the same location regardless of the size of the sheets being fed, only a single document registration procedure is required for each mode of operation (manual, RDH, SALDH and SADH). The location of the other edges of sheets fed onto platen 30 (the leading side edge and top edge) are determined based on the location of the trailing and bottom edges determined by the document registration procedure and the size (A4, 81/2×11", etc.) of the sheets being fed.
Test document 110 can also include a number of reference scales 118 located adjacent each of its edges. These reference scales 118 comprise a series of equally spaced lines which are parallel to their corresponding document edge. For example, each reference scale 118 can include three lines which are spaced one millimeter from each other, with the first line being spaced one millimeter from the document edge. The reference scales can be used to visually inspect the accuracy of the document registration system. The test document can be scanned by scan carriage 40 and either printed out with a printer or displayed on monitor 50. The number and position of the lines in each reference scale 118 can then be viewed to determine whether the document registration procedure has functioned properly. It is understood that reference scales 118 are not used or required for the present invention, but only function as a means for inspecting the accuracy of the document registration procedure.
The process for registering scan carriage 40 to documents placed on platen 30 will be described with reference to FIG. 5. The process used to determine the registration locations of sheets fed from the RDH, SADH, SALDH or manually is similar, however when using the RDH, SADH or SALDH, a sheet is fed onto the platen and its trailing side edge and bottom edge are located using the present invention a plurality of times. An average is determined from the plurality of runs and this value is used as the registration location for the RDH, SADH and SALDH modes. The average is used because the UDH does not locate sheets on platen 30 in exactly the same position every time, but operates within a standard deviation. Thus, determining the average over a number of sheets fed by the RDH, SADH and SALDH ensures that the registration position determined for these modes is as close as possible to the actual location to which the sheets are delivered by the UDH. For example, the average of five or ten runs can be used for determining the sheet location for the RDH, SADH and SALDH modes.
As discussed above, four specific registration set up procedures are required. The four registration set up procedures are as follows: manual platen, RDH (simplex and duplex), SADH (implicitly includes CFF) and SALDH. The basic concept used to perform the registration set up includes using the Charge Coupled Devices of the scanner array 11 to find the white/black transition on a special test document 110 in the slow scan direction and finding two other white/black transitions for the fast scan direction. While manual platen registration requires only one edge finding cycle, SADH, SALDH and RDH require five or more document edge finding cycles with the average of tee cycles being used as the final registration value. CFF registration is at the same place as SADH, and therefore is determined based upon the values used in SADH.
Using RDH as an example, the registration set up diagnostic will now be described. Test sheet 110 is placed in RDH stacking tray 21 and moved onto platen 30 in the usual manner. Once on platen 30, a previously stored theoretical position SS1M of the trailing edge of the sheet is obtained from non-volatile memory (NVM). This value can be a default value or the last value at which a sheet was registered. Scan carriage 40 is then moved and located at a position SS1S which is spaced a predetermined distance from the theoretical position SS1M. Scan carriage 40 is then moved to the right while operating at least two of the scanners of the scan carriage until the black targets 112, 114 on the test sheet are detected by the operating scanners. The detection of the black areas on test sheet 110 are used to determine the location of the trailing side edge 111 of the sheet, which position is then stored in a first memory. While in the above-described example the location SS1S is to the left of the theoretical position SS1M and located over the surface of the test sheet, position SS1S could also be to the right of the theoretical position SS1M. In this case the scan carriage 40 would be moved to the left from position SS1S while operating at least two of the scanners to locate trailing side edge 111. It is preferable to locate position SS1S over the test document and scan for the white/black transition which exists on test document 110 because the white platen cover can contain dirt, marks or defects (e.g., nicks and cuts) which could cause the scanners to incorrectly detect the trailing or bottom edges of the test document. That is, when scanning for the white/black transition from the white platen cover to the black test pattern on test document 110, marks or defects on the platen cover (which can also be the transport belt 24 of the UDH) may be interpreted to be the white/black transition point. As mentioned above, when operating in RDH, SALDH or SADH modes, a test sheet is fed onto platen at least five times, each time a reading for the registration position being stored in the first memory. After the desired number of runs are made, the average value of the detected target position is determined and used for determining the registration position of subsequent sheets.
After finding the trailing edge of the sheet, the scan carriage is moved to a first scan position FS1a where all of the scanners in the scanning array are then actuated to detect the bottom edge of the sheet 110. The scan carriage 40 is then moved to a second fast scan position FS1b where this same procedure is again performed. The fast scan operation is performed on each fed test sheet subsequent to performance of the slow scan operation on that sheet. Thus when using RDH, SALDH and SADH, the fast scan operation is performed, for example, five or ten times. As stated above, the information from the fast scans is used to detect top-to-bottom skew of the document as well as the locations of the top and bottom edges of the document.
The information obtained from the slow scan and fast scan procedures is used to control the starting position of scan carriage 40 for subsequent sheets to be fed onto platen 30. Thus, the starting position of scan carriage 40 is automatically determined by the scanning device. This eliminates the need for a technician to physically adjust portions of the document handler or scan carriage and is also more accurate than physical adjusting. Additionally, by only detecting the location of the trailing edge of the document at two spaced locations, the side-to-side skew of the document can be determined and outputted to an operator so that he can determine whether or not adjustments are necessary. Registration of scan carriage 40 to the document locations is performed when the UDH 20 is initially assembled onto the document scanner's platen 30 and whenever parts of a previously registered system are replaced which will require re-registration of the system. Automatic document registration is more accurate than registration by physical adjustment and makes full use of the system hardware (the CCD's) which are already available. Additionally, since no copies need to be made to determine registration, misalignments which may exist in the printing system do not show up as misalignments between the UDH and scanning system.
Another important feature of the present invention is that CFF document registration is determined based on the SADH registration location. CFF registration is normally difficult and costly for a number of reasons. Reasons include CFF hole size and placement variability (sheet to sheet and form to form), difficulty and expense of obtaining or making a "nominal" test sheet and lastly, the time required to perform the setup is excessive and subject to human error. The present invention uses the amount of adjustment used to adjust the SADH registration position from its initial theoretical position to its actual position to adjust the registration position for CFF. At the same time the SADH registration location is being updated to eliminate any mean error, the CFF registration location can be modified the same amount and direction as was SADH. This is valid because the drives used are the same for SADH and CFF and, therefore, the magnitude and direction of the mean registration error should be the same. It is desirable to keep the actual SADH registration locations independent of the CFF registration locations in NVM so that any post semiautomatic set up fine tuning of either mode of operation can be performed independently. This method is preferable over a stand alone CFF mode setup because there is zero set up time, errors due to non-nominal CFF forms are eliminated and human errors are eliminated.
The present invention can also be used to locate the calibration strip 60 which is used to calibrate the scanners in scanning array 11. Calibration strip 60 includes a black strip 62 and a white strip 64 and is used to calibrate the scanners in scanning array 11 in a manner well known in the art. While previous systems required an operator to adjust scan carriage 40 so that it would be registered to calibration strip 60, the present invention can be utilized to locate the white to black transition of calibration strip 60. Thus, no physical adjustments are necessary. To locate the white/black transition of calibration strip 60, a previously stored theoretical or default location is obtained from NVM. The scan carriage 40 is moved a predetermined distance from the theoretical position and then the carriage is moved towards the theoretical position while operating at least some of the CCD's in scanner array 11 until the black/white transition is detected. The location of carriage 40 where the black/white transition is detected is stored in memory and the CCD's in scanning array are then calibrated by moving scan carriage 40 to the left and to the right of the stored position and performing standard calibration procedures. The location of the calibration strip is determined each time the scanning system 10 is turned on and, consequently, the scanning system never has to be manually adjusted so that the scanner array 11 is aligned with the calibration strip. This reduces the need for high tolerances between scan carriage 40 and calibration bar 60 with scanning system 10. Also, the calibration strip can be made smaller with the present invention, reducing costs and space requirements, because the scan carriage will be able to be located adjacent the calibration bar with a much higher precision than was previously attainable. The present invention also makes full use of the existing system hardware (the scanning array) to locate the calibration strip, eliminating the need for separate sensors to control the placement of the movable carriage adjacent the calibration strip.
While the present invention has been described with reference to particular preferred embodiments, the invention is not limited to the specific examples given. Other embodiments and modifications can be made by those skilled in the art without departing from the spirit and scope of the attached claims.
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A method of locating the position of an object on the platen of a raster input scanner having a movable scan carriage and an extended array of scanners is disclosed. The method includes the steps of obtaining a previously stored theoretical position of the object from a memory, locating the scan carriage at a position spaced a predetermined distance from the previously stored position, moving the scan carriage toward the previously stored position while operating at least some of the scanners until a target on the object is detected by the operating scanners, and storing a target position of the scan carriage where the target is detected. The target position can represent the location of the scanner's calibration strip or the registration position of a document. After the target position is stored, the scan carriage can be located at the target position for calibrating the scanners if the target position represents the location of the calibration strip. Alternatively, the scan carriage can be located at the target position prior to actuating the scanners for each subsequent document to be scanned if the target position represents a document registration position. This procedure is repeated to determine the document registration positions for documents which are placed on the platen manually, by an SADH or SALDH input, by a CFF input, or by an RDH input.
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This application is a National Stage completion of PCT/EP2011/053114 filed Mar. 2, 2011, which claims priority from German patent application serial no. 10 2010 028 282.0 filed Apr. 28, 2010.
FIELD OF THE INVENTION
The invention relates to a method for determining a startup gear in a motor vehicle, the drive train of which comprises a drive engine built as an internal combustion engine, a startup element built as an automated friction clutch, and a transmission built as an automatic stepped transmission, wherein a startup gear is determined for startup from standstill while maintaining a load limit of the friction clutch.
BACKGROUND OF THE INVENTION
For a startup from standstill with a multi-stage stepped transmission, in principle, several gears can be considered for the startup gear. One such startup situation occurs in particular in the case of a startup on a plane and on an incline. With the startup, the engine torque that can be generated by the drive engine and transmitted to the friction clutch as the startup torque must be sufficiently high in order to compensate for the stationary drive resistance of the motor vehicle, which is formed in this situation by the rolling resistance and incline resistance, given the overall transmission ratio determined by the respective startup gear and the efficiency of the drive train, and in addition, to deliver excess torque for startup acceleration of the motor vehicle.
In the process, it must be considered that active output drive-side power take-offs, that is, power take-offs disposed at the transmission and/or the axle transmission, reduce the engine torque that can be used for startup, which can be considered as a fictional additional resistance for the determination of the startup gear. In contrast, auxiliary consumers driven directly by the drive engine, such as an electric generator, a servo pump of a servo steering, and an air conditioning compressor of an air conditioning system, as well as active drive-side power take-offs, that is, power take-offs disposed directly at the drive engine, reduce, already at the source of the rotational energy, the engine torque that can be delivered by the drive engine to the friction clutch and available for startup.
Furthermore, the startup acceleration should correspond to the respective power request by the driver, which is given by the gas pedal deflection or the gas pedal position respectively, increasing with increasing gas pedal deflection and decreasing with increasing road incline. With increasing gas pedal deflection at a constant road incline, the driver accordingly expects faster startup acceleration, whereas in contrast with an increasing road incline with a constant gas pedal position the driver expects slower startup acceleration.
A determination of the startup gear depending only on the startup situation typically occurs using the characteristic curves or characteristic maps, which are modified to the respective vehicle configuration using complex application methods, and which contain at least the vehicle mass, the roadway incline and the gas pedal position as parameters.
For a startup from standstill the friction clutch can be a passive engageable single or multi-disc dry clutch or an active engageable multi-disc clutch, for bridging the speed difference between the engine speed and the transmission input speed and the transmission input shaft in slipping operation, until the motor vehicle has accelerated to the extent that synchronous running is attained at the input and output sides of the friction clutch so that the clutch can be completely engaged.
The startup-dependent slipping operation represents a high mechanical and thermal load for the friction clutch that increases with the value of the startup torque, the value of the slip speed and the duration of the slipping operation, and which forms an essential parameter for determining the startup gear.
If the startup gear is set too low, fast startup acceleration and a correspondingly shorter slipping operation of the friction clutch is possible. Due to the high transmission ratio of the startup gear, noise develops, and due to the high startup speed, the fuel consumption of the internal combustion engine is unfavorably high.
In addition, due to the fast startup acceleration a shift speed is attained relatively quickly and a shift is triggered to a higher gear. This is considered uncomfortable and particularly at high drive resistance, for instance on a steep incline or on difficult terrain, can lead to a strong delay of the vehicle during the shift-dependent interruption of the tractive force and consequently to an interruption of the startup.
If in contrast, the startup gear is too high, the slipping speed is relatively high at the friction clutch due to the low transmission ratio of the startup gear. Due to the slow startup acceleration, the duration of the slipping operation can be so long that the friction clutch is thermally overloaded.
Therefore, the general aim is to perform a startup of a motor vehicle in the highest possible gear, however without mechanically and thermally overloading the friction clutch in the process. Thus, methods for determining a startup gear are known from the documents DE 198 39 837 A1 and U.S. Pat. No. 6,953,410 B2, with which the highest possible startup gear is determined from the present drive resistance of the motor vehicle and the available engine torque of the drive train so that the expected duration of slipping of the friction clutch during the startup and/or the thermal energy created in friction clutch in slipping operation do not exceed predetermined limit values.
The document U.S. Pat. No. 7,220,215 B2 describes a commercial vehicle with a control device with which the highest possible startup gear is determined so the maximal engine torque that can be generated by the drive engine at idle speed is sufficient for the startup, and the thermal energy created in the process in the friction clutch does not exceed a predetermined limit value.
In the case of commercial vehicles, the drive engines are usually designed as turbo-charged diesel engines, which have a specific load build-up characteristic. According to the document DE 10 2008 054 802 A1, which was previously unpublished, and which discloses a method for controlling an automatic stepped transmission depending on the dynamic operating characteristics of a turbo-charged internal combustion engine, a turbo-charged internal combustion engine can spontaneously, that is with high torque gradients, only reach an intake torque lying below the full load torque.
A further increase of the engine torque is briefly possible, although with low torque gradients, only above a boost threshold speed, after which the turbo-charger creates a significant increase of the charge pressure and thus the engine torque. Thus, aside from the idle speed, cut-off speed and the full load torque characteristic curve, the dynamic behavior of a turbo-charged internal combustion engine is also determined by the boost threshold speed and the intake torque characteristic curve as well as by the present torque gradients, at least in certain regions.
Therefore, the dynamic operating properties of a drive engine built as a turbo-charged internal combustion engine are also significant for determining a startup gear, because starting from the idle speed only the intake torque is spontaneously built up and usable as the startup torque. If the intake torque is not sufficient as startup torque, the engine speed must be increased above the boost threshold speed, in order to be able to increase the engine torque above the intake torque by increasing the charge pressure. In this case however, due to the hereby increased slipping speed and the slowdown of the torque buildup, the mechanical and thermal load of the friction clutch increases significantly.
With the previously known methods for determining a startup gear, the present load state of the friction clutch, repeated startups without significant cooling of the friction clutch in between, and the dynamic operating properties of the drive engine were not considered, or not sufficiently considered. This can have the consequence that the friction clutch, despite nominally maintaining the intended load limit, is mechanically and/or thermally overloaded, and consequently does not attain an intended service life or is destroyed during a startup procedure.
SUMMARY OF THE INVENTION
Therefore, the problem addressed by the present invention is to propose a method for determining a startup gear for startup from standstill with a motor vehicle of the initially named type, with which the present operating state and the operating properties of the friction clutch and the drive engine are considered, and thus overload of the friction clutch can be reliably avoided.
This problem is solved in that a load-independent startup gear G Anf — Typ is determined with which in the case of a startup, this startup would occur under the present starting conditions (m Fzg , α FB , x FP ) without taking into consideration the current load state of the friction clutch and without complying with a load limit of the friction clutch, that at least one load-specific startup gear (G Anf — Max1 , G Anf — MaxN , G Anf — Lim , G Anf —Def ) is determined as the highest startup gear, with which in the case of a startup under the present starting conditions a predefined load limit of the friction clutch would be maintained while taking into consideration the present load state of the friction clutch, and that the startup gear (G Anf ) intended for the present startup is determined in a minimum selection as the lowest startup gear of the load-independent startup gear and the at least one load-specific startup gear, thus (G Anf =min(G Anf — Typ , G Anf — Max1 , G Anf — MaxN , G Anf — Lim , G Anf — Def )).
Accordingly, the invention assumes a known motor vehicle, a commercial vehicle for example, the drive train of which comprises a drive engine built as an internal combustion engine, a startup element built as an automated friction clutch, and a transmission built as an automatic stepped transmission. For startup from standstill, the provided startup gear G Anf according to the invention is determined from a minimum selection of at least two determined startup gears.
A first startup gear G Anf — Typ is determined only depending on the present startup conditions, which are given by the present drive resistance of the motor vehicle and the power request of the driver, independent of the load, that is, without taking into consideration the present load state of the friction clutch and without complying with a load limit of the friction clutch. Whereas the drive resistance is determined largely by the vehicle mass m Fzg and the roadway incline α FB , the power request of the driver is largely given by the gas pedal deflection x FP . This load-independent startup gear G Anf — Typ can presently be calculated by means of startup parameters m Fzg , α FB , x FP recorded by sensors or predetermined in a preceding travel cycle, or calculated in a known manner from corresponding characteristic curves and characteristic maps.
In contrast, at least one additional startup gear G Anf — Max1 , G Anf — MaxN , G Anf — Lim , G Anf — Def is determined however load-specific as the highest startup gear with which startup would occur in the case of a startup under the present startup conditions while adhering to a predetermined load limit of the friction clutch with consideration of the present load state of the friction clutch. The mechanical and thermal load of the friction clutch occurring with the respective startup gear can be calculated relatively precisely from the intended speed and torque progressions.
Using the proposed minimum selection of the load-independent startup gear G Anf — Typ and the at least one load-specific startup gear G Anf — Max1 , G Anf — MaxN , G Anf — Lim , G Anf — Def , it is guaranteed that the intended load limit of the friction clutch is actually maintained. If the intended load limit of the friction clutch is maintained with the typically used load-independent startup gear G Anf — Typ , the startup occurs with the startup gear expected by the driver, (G Anf =G Anf — Typ ). Otherwise, the startup occurs with the respective lowest, load-specific startup gear G Anf — Max1 , G Anf — MaxN , G Anf — Lim , G Anf — Def .
Particularly in the case of commercial vehicles, the drive engine is frequently built as a turbo-charge internal combustion engine which has a specific load build-up characteristic. Thus, a turbo-charged internal combustion engine below the boost threshold speed n L — min can spontaneously, that is, with high torque gradients, only reach an intake torque M S lying below the full load torque M VL (n M ). Therefore, with a design of the drive engine as a turbo-charged internal combustion engine, in addition a turbo-specific startup gear G Anf — MS is expediently determined as the highest startup gear with which the intake torque M S of the drive engine is sufficient as startup torque for a startup under the present startup conditions, and the turbo-specific startup gear G Anf — MS is considered in the minimum selection of the startup gears.
The relevant data which represents the dynamic operating characteristics of the internal combustion engine can be taken either directly from the engine control device or from a data store of the transmission control device. As already described in the document DE 10 2008 054 802 A1, this data that corresponds to the vehicle configuration, can be transferred to the data store of the transmission control device at the end of the production line of the motor vehicle, and later during travel operation can be adapted through comparison with the current operating data, particularly of the drive engine, that is, adapted to the changed operating characteristics. By accessing such updated data, the present method for the determining a startup gear is automatically adapted to the changed operating characteristics of the motor vehicle or of the drive engine.
A load-specific limit startup gear G Anf — Max1 can be determined as the highest startup gear with which a single startup is possible with startup under the present startup conditions (m Fzg , α FB , x FP ) without exceeding a breakdown-specific load limit of the friction clutch in the process. Because in the case of a startup with the limit startup gear G Anf — Max1 the highest permissible load of the friction clutch would arise, this represents the highest possible startup gear under the present operating conditions (m Fzg , α FB , x FP ).
A further load-specific startup gear G Anf — MaxN can be determined as the highest startup gear with which an expected number of consecutive startups is possible without substantial cooling phases with startup under the present startup conditions (m Fzg , α FB , x FP ) without exceeding the breakdown-specific load limit of the friction clutch in the process. Due to immediately consecutive startups and the corresponding load of the friction clutch, in most cases this startup gear G Anf — MaxN lies significantly below the limit startup gear G Anf — Max1 , and the number of possible sequential startups is preferably relatively small.
The expected number of consecutive startups without substantial cooling phases that is used here can be determined based on the use profile of the motor vehicle and/or from the present driving situation of the motor vehicle. With the motor vehicle, for instance, a garbage truck or a package or postal delivery truck that travels from one house to another or, as in the case of a city bus, that travels from bus stop to bus stop, the expected number of the sequential startups can be specifically predetermined, or adaptively determined from the past operating phases.
Likewise, the expected number of sequential startups can be determined from the present traffic situation, such as stop-and-go operation in a traffic jam or in inner-city commuter traffic. Here, the load of the friction clutch that occurs in each case depends, in addition to the vehicle mass m Fzg , substantially on the average present roadway incline, α FB , that is, the corresponding topographic data, which can be determined in conjunction with a navigation device in the prior travel operation phases, or can be contained in a digital street map provided with corresponding data.
A spontaneous failure of the friction clutch is caused largely due to thermal overloading, that is, a friction-dependent introduction of heat that is too large.
Accordingly, the failure-specific load limit of the friction clutch can be defined as a temperature limit value T K — max of the friction clutch that must be maintained for avoiding a spontaneous failure of the friction clutch. Analogous to this, the present load state of the friction clutch is determined before startup in this case using the present clutch temperature T K of the friction clutch. The present clutch temperature T K of the friction clutch can be recorded using a temperature sensor disposed at the friction clutch for example, or can be appropriately calculated. Accordingly, the load of the friction clutch during a startup procedure is determined as the estimated temperature increase ΔT K by which the currently present clutch temperature T K will be increased during the startup procedure.
The failure-specific load limit of the friction clutch can however also be defined as a thermal capacity limit Q K — max of the friction clutch, which should be maintained for avoiding a spontaneous failure of the friction clutch. Accordingly in this case, the present load state of the friction clutch is determined before the startup using the present thermal content Q K of the friction clutch, which is given by the calculated heat introduction with past startups and the estimated thermal loss during the interspersed cooling phases. The load of the friction clutch due to a startup procedure is then determined as the anticipated increase of the thermal content ΔQ K by which the currently present thermal content Q K is increased during the startup procedure.
A driving performance oriented load-specific startup gear G Anf — Lim can be determined as the highest startup gear with which startup under the present startup conditions (m Fzg , α FB , x FP ) largely fulfills the driving performance request of the driver, and a service life-specific load limit of the friction clutch is exceeded maximally by a specific tolerance threshold.
The service life of a friction clutch is determined by the mechanical wear of the friction linings, as long as no thermal overloading has occurred in the meantime. If a specific wear per startup is given as a service life-specific load limit for attaining a designated service life of the friction clutch, this is an average value which must be maintained only on average, that is, averaged over many startups. Accordingly this load limit value, as is intended here with the drive performance-oriented startup gear G Anf — Lim for satisfying the power request of the driver, can be moderately exceeded on a sporadic basis without endangering the maintenance of the service life of the friction clutch.
This performance-oriented startup gear G Anf — Lim also expediently represents the highest startup gear to which the startup gear G Anf determined in the minimum selection, can be corrected manually by the driver, that is, by an appropriate intervention of the driver in the control of the gear selection, for instance by deviation of a shift lever located in a manual shift gate into an upshift or downshift direction.
In additional load-specific startup gear G Anf — Def can be determined as the highest startup gear with which the service life-specific load limit of the friction clutch is not exceeded with a startup under the present drive conditions (m Fzg , α FB , x FP ).
Because the mechanical wear of the friction linings per startup can barely be detected by sensors, the service life-specific load limit of the friction clutch can be defined alternatively as an incremental limit value of the clutch temperature ΔT K — max of the friction clutch, by which the present clutch temperature T K is to be maximally increased during the intended startup procedure for attaining a specified service life goal of the friction clutch. The temperature increase ΔT K of the friction clutch is used in this case as an equivalent for the mechanical wear of the friction linings during startup.
As an alternative to this, the service life-specific load limit of the friction clutch can also be defined as an incremental limit value of the thermal content ΔQ K — max of the friction clutch, by which the present thermal content Q K of the friction clutch is to be maximally increased during the intended startup procedure for attaining a specified service life goal of the friction clutch. In this case, the increase ΔQ K of the thermal content of the friction clutch is used as an equivalent to the mechanical wear of the friction linings during a startup.
If necessary, a speed-specific startup gear G Anf — vZiel can be determined in addition as the highest startup gear with which a predetermined target speed can be attained without a downshift with the engaged friction clutch in the case of a startup under the present startup conditions (m Fzg , α FB , x FP ), and this speed-specific startup gear G Anf — vZiel can be considered with the named minimum selection of the startup gears. The startup gear chosen here must not be too high such that the target speed is exceeded already at an idle engine speed and an engaged friction clutch, which would require a downshift and traveling with a slipping friction clutch.
The consideration the speed-specific startup gear G Anf — vZiel is particularly significant for specific-use vehicles, such as collection vehicles which must travel from loading station to the loading station or concrete mixers which must deposit concrete caterpillars, for which the target speed v Ziel of the respective startup is relatively low. With such applications, the target speed v Ziel to be attained should be as close as possible to the idle speed n idle of the drive engine, that is, the present drive resistance in the case of an intake engine can be compensated by the corresponding full load torque M VL (n M ) of the drive engine, and in the case of a turbo-charged internal combustion engine by the intake torque M S of the drive engine.
If the startup gear G Anf determined in the minimum selection is not available, expediently the next lowest startup gear (G Anf =G Anf−1 ) is used for the intended startup because overloading of the friction clutch is reliably excluded with this startup gear.
However, if the startup gear G Anf determined in the minimum selection and the next lowest startup gear G Anf−1 are not available, the next higher startup gear (G Anf =G Anf+1 ) can also be used for the intended startup; the use thereof however under unfavorable operating conditions can be associated with overloading of the friction clutch.
If neither the startup gear G Anf determined in the minimum selection nor the next lowest startup gear G Anf−1 are available for the intended startup, the search for the next lowest gear continues until the first gear of the stepped transmission is reached. The next higher startup gear (G Anf =G Anf+1 ) for the intended startup is only used if neither the startup gear G Anf determined in the minimum selection nor the next lower startup gear are available up until reaching the first gear of the step transmission as the startup gear.
A thermal overload of the friction clutch can be assumed particularly if the next higher startup gear G Anf+1 lies above the load specific limit startup gear G Anf — Max1 . Therefore in this case, the startup is typically prevented and this is indicated to the driver by issuing an audible and or visual warning signal.
The startup with the startup gear G Anf+1 lying above the load-specific limit startup gear G Anf — Max1 can be permissible however in emergency operation, if a specific driver action requires an emergency startup. An emergency startup can be requested by the driver for example by simultaneously activating the gas pedal and an emergency switch, or by holding of the gas pedal in the maximum setting thereof for a prolonged period.
Such an emergency startup is required for example if the motor vehicle is located in a hazardous location such as in an intersection or on a railroad crossing. In such an emergency situation, an emergency startup is viewed as advantageous even under inclusion of overloading or destruction of the friction clutch in order to avoid even greater damage such as that caused by a collision with another vehicle or with the train.
With a known maneuvering situation, an additional maneuvering-specific startup gear G Anf — Rang can be determined as the highest startup gear with which under the present startup conditions (m Fzg , α FB , x FP ) the friction power generated at the friction clutch in the continued slipping operation corresponds more or less to the available cooling power of the friction clutch. In this case, this range-specific startup gear G Anf — Rang is also considered with the minimum selection of the startup gears.
BRIEF DESCRIPTION OF THE DRAWINGS
For illustrating the invention, the description is accompanied by a drawing with an example embodiment. The figures show:
FIG. 1 the determination of a load-independent startup gear for startup from standstill in a transmission ratio/incline graph,
FIG. 2 a schematic of a drive train of a heavy-duty commercial vehicle,
FIG. 3 an engine dynamic characteristic curve of a turbo-charged internal combustion engine,
FIG. 4 a the torque build-up of an internal combustion engine according to FIG. 3 with an engine speed controlled below the boost threshold speed, thus (n M ≦n L — min ), and
FIG. 4 b the torque build-up of an internal combustion engine according to FIG. 3 with an engine speed controlled above the boost threshold speed, thus (n M >n L — min ).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A drive train, shown schematically in FIG. 2 , of a heavy-duty commercial vehicle comprises a drive engine designed as a turbo-charged internal combustion engine VM, a startup element designed as an automated friction clutch K, and a transmission designed as an automated stepped transmission G. The stepped transmission G can be connected on the input side, via the friction clutch K, to the drive shaft (crankshaft) of the internal combustion engine VM, and on the output side, via a cardan shaft, to the axle transmission GA (axle differential) of the drive axle.
At least one auxiliary consumer NA and optionally at least one drive-side power take-off PTO are disposed at the internal combustion engine VM, which in the driven state reduce the engine torque M M of the internal combustion engine VM that can be delivered at the friction clutch and that is available for a startup process. At least two further output-side power takeoff-offs PTO are disposed at the stepped transmission G and the axle transmission GA, and further reduce the engine torque M M transmitted via the friction clutch K into the stepped transmission such that with a startup procedure a correspondingly reduced torque is effective at the drive wheels of the drive axle for overcoming the drive resistance and attaining an at least minimal startup acceleration.
With a startup procedure, the internal combustion engine VM must therefore be able to instantaneously generate engine torque M M and to deliver the torque at the friction clutch K so that such torque, minus the drive torque for the auxiliary consumers NA and the drive side power take-offs PTO, is sufficient for attaining acceptable startup acceleration. For this purpose, the engine torque M M transferred by the friction clutch K must be sufficiently high that the engine torque, minus the drive torques for the output drive side power take-off PTO, exceeds the drive resistance torque resulting from the present drive resistance, that is, the reduced drive resistance torque M FW given the overall transmission ratio and the efficiency of the drive train at the input shaft of the stepped transmission G, exceeds to such a degree that the excess torque is sufficient at least for a minimal startup acceleration.
The graph in FIG. 1 shows in general the reciprocal of the transmission ratio i G over the roadway incline α FB , which illustrates the simplified determination of a startup gear G Anf — Typ , which for startup from standstill is determined depending only on the present startup conditions, for instance the vehicle mass m Fzg , the roadway incline α FB and the gas pedal position x FP , that is, without considering a predetermined breakdown-specific or service life-specific load limit of the friction clutch.
For this purpose, a dash-dotted characteristic line in FIG. 1 shows the reciprocal of the respective transmission ratio i Fw for a specific vehicle mass m Fzg depending on the roadway incline α FB , the maximum engine torque M max that can be spontaneously generated which is necessary to compensate for the specific drive resistance in this situation, formed by the sum of the incline resistance and the rolling resistance.
Because a higher drive torque is necessary at the drive wheels for the additional generation of sufficient startup acceleration, the respective startup gear G Anf — Typ must have a correspondingly higher transmission ratio. For this purpose, FIG. 1 correspondingly shows the reciprocal values of the transmission ratios of the possible startup gears G 1 -G 5 in a stepped characteristic curve. With the presence of a specific roadway incline α FB * (point a), the dot-dashed characteristic curve provides a transmission ratio i FW (point b) with which the present drive resistance is compensated with the maximum available engine torque M max . For attaining an at least minimum vehicle acceleration the amount of which can be influenced by the driver using the gas pedal position x FP , the third gear G 3 for example is presently determined as a startup gear G Anf — Typ (point c), which has a correspondingly higher transmission ratio.
In the present method for determining a startup gear, there are, however additional, specifically load-specific startup gears determined according to different criteria. Thus, a further load-specific startup gear G Anf — MaxN can be determined as the highest startup gear with which an expected number of consecutive startups is possible without substantial cooling phases in the case of startup under the present startup conditions (m Fzg , α FB , x FP ) without exceeding a breakdown-specific load limit of the friction clutch in the process.
Likewise, a load-specific startup gear G Anf — Def can be determined as the highest startup gear with which the service life-specific load limit of the friction clutch is not exceeded with a startup under the present startup conditions (m Fzg , α FB , x FP ).
With the design of the drive engine as a turbo-charged internal combustion engine, a turbo-specific startup gear G Anf — MS is also preferably determined as the highest startup gear with which the intake torque M S of the drive engine is sufficient as the startup torque in the case of a startup under the present startup conditions (m Fzg , α FB , x FP ), whereby a very low, startup speed n Anf lying near the idle speed n idle is possible.
The startup gear G Anf provided for the present startup is determined in a minimum selection from the number of specific startup gears G Anf — Typ , G Anf — MaxN , G Anf — Def , G Anf — MS , that is, the lowest of the startup gears is selected.
The intake torque M S required for the determination of the turbo-specific startup gear M Anf — MS can be read directly from the engine control device or can be taken from an engine dynamic characteristic map, known from the document DE 10 2009 054 802 A1, that can be stored in a data store of the transmission control device, and is shown for example in FIG. 3 .
The engine dynamic characteristic map represented in FIG. 3 in a torque/speed diagram contains the immediately available maximum torque M max of the internal combustion engine and the maximum torque gradient (dM M /dt) max , with which the immediately available maximum torque M max can be attained as quickly as possible, in each case of a function of the present engine torque M M and the present engine speed n M , thus (M max =f(M M , n M ), (dM M /dt) max =f(M M , n M )).
The engine dynamic characteristic map is bounded by the stationary full load torque characteristic curve M VL (n M ), the zero torque curve (M M =0), the idle speed n idle and the cut-off speed n lim of the internal combustion engine. The engine dynamic characteristic map is subdivided into four operating regions A, B, C, D by the intake torque characteristic curve M S (n M ) of the intake torque, simplified here as assumed to be constant M S =const., and the boost threshold speed n L — min of the internal combustion engine.
In the first region A (0≦M M <M S , n idle ≦n M <n L — min ) that is below the intake torque characteristic curve M S =const. and below the boost threshold speed n L — min , the immediately available maximum torque M max (n M ) of the internal combustion engine is formed in each case by the corresponding value of the intake torque M S , thus (M max (n M )=M S ). However, as the intake torque M S in this region is constant (M S =const.), the immediately available maximum torque M max of the internal combustion engine is represented by a single value (M max =M S =const.). Independent of this, the very high maximum torque gradient (dM M /dt) max in operating region A can also be represented by a single value.
In the second region B (0≦M M <M S , n L — min ≦n M n lim ) lying below the intake torque characteristic curve M S =const. and above the boost threshold speed n L — min , the immediately available maximum torque M max (n M ) of the internal combustion engine is similarly given in each case by the corresponding value of the intake torque M S . Because the intake torque M S in this region has a constant progression (M S =const.), the immediately available maximum torque M max of the internal combustion engine also in the region B is represented by a single value (M max =M S ==const.). As with region A, also in region B, the maximum torque gradient (dM M /dt) max that is also very high beneath the intake torque characteristic curve M S =const. can also be expressed by a single value.
In the third region C (M S ≦M M <M VL (n M ), n L — min ≦n M <n lim ), adjacent to region B, and lying above the intake torque characteristic curve M S =const. and above the boost threshold speed n L — min , a further increase of the engine torque M M is possible up to the respective value of the stationary full load torque characteristic curve M VL (n M ), however, with a significantly lower maximum torque gradient (dM M /dt) max than in the regions A and B, i.e., below the intake torque characteristic curve M S =const.
In the fourth region D (M S ≦M M <M VL (n M ), n idle ≦n M <n L — min ), adjoining at the first region A, above the intake torque characteristic curve M S =const. and below the boost threshold speed n L — min , a further rapid increase of the engine torque M M is not possible without an increase of the engine speed n M above the boost threshold speed n L — min . Consequently, in operating region D, the immediately available maximum torque M max (n M ) of the internal combustion engine equals the corresponding value of the intake torque M S , thus (M max (n M )=M S =const.) and the maximum torque gradient (dM M /dt) max equals zero, thus ((dM M /dt) max =0).
An operating region E which cannot be reached in normal driving operation and thus is not relevant, can be defined above the full load torque characteristic curve M VL (n M ). Below the full load torque characteristic curve M VL (n M ) and the idle speed n idle , there is an undesirable but technically attainable operating region F, into which the internal combustion engine can be pushed dynamically from an engine speed n M lying near the idle speed n idle , for example due to a rapid engagement of the friction clutch, and in which there is a danger of stalling the internal combustion engine. In addition, a nearby region lying immediately below the full load torque characteristic curve M VL (n M ) can be defined as an additional operating region V, in which the internal combustion engine under full load, that is along the full load torque characteristic curve M VL (n M ), can be pushed to a lower engine speed n M or controlled to higher engine speed n M .
For a startup procedure considered here, with which the drive engine is to be controlled from the idle speed n idle to a startup speed n Anf and from the idle torque M idle ≈0 to the determined startup torque M Anf , it must accordingly be noted that the drive engine can be spontaneously loaded, that is, with high torque gradients dM M /dt, only up to the intake torque M S , if the engine speed n M remains below the boost threshold speed n L — min . This relationship is represented greatly simplified in the torque progression M M (t) in the image insert (a) of FIG. 3 and in the time progression of FIG. 4 a.
Likewise it is to be noted for the present determination of the startup gear that the drive engine must be accelerated above the boost threshold speed n L — min for the immediate setting of an engine torque M M lying above the intake torque M S , that is, it must be controlled from the operating region A into the operating region B, because a further rapid increase of the engine torque M M is possible only above the boost threshold speed n L — min , even with lower torque gradients dM M /dt. This relationship is illustrated in a greatly simplified manner in the torque progression M M (t) in the image insert (b) of FIG. 3 and in the time progression of FIG. 4 b.
REFERENCE CHARACTERS
a point in FIG. 1
b point in FIG. 1
c point in FIG. 1
A operating region
B operating region
C operating region
D operating region
E operating region
F operating region
G stepped transmission, transmission
G Anf startup gear
G Anf+1 next higher startup gear
G Anf−1 next lower startup gear
G anf — Def load-specific startup gear
G anf — Lim load-specific startup gear
G Anf — max highest possible startup gear
G Anf — MaxN load-specific startup gear
G Anf — Max1 load-specific limit startup gear
G Anf — min lowest possible startup gear
G anf — MS turbo-specific startup gear
G Anf — Rang maneuvering-specific startup gear
G Anf — Typ load independent startup gear
G Anf — vZiel speed specific startup gear
GA axle transmission, axle differential
G 1 -G 5 possible startup gears
i FW transmission ratio for compensating the drive resistance
i G transmission ratio
K friction clutch, startup element
M Anf startup torque
M FW drive resistance torque
m Fzg vehicle mass
M idle idle speed torque
M M engine torque
M max maximum torque
M S intake torque
M VL full load torque
n Anf startup speed
n idle idle speed of rotation
n L — min boost threshold speed
n lim cut-off speed
n M engine speed
NA auxiliary consumer
PTO power take-off
Q K thermal content in the friction clutch
Q K — max thermal content limit of the friction clutch
t time
t 0 time
T K clutch temperature
T K — max temperature limit value of the friction clutch
V operating region
VM internal combustion engine, startup engine
x FP gas pedal deflection, gas pedal position
α FB roadway incline
α FB * present roadway incline
ΔQ K — max incremental limit value of the thermal content (of K)
ΔT K — max incremental limit value of the clutch temperature
ΔT K temperature increase
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A method for determining a startup gear in a motor vehicle for starting from standstill while maintaining a load limit of the clutch in a the drive train which comprises a drive engine built as an internal combustion engine, a friction clutch, and an automatic stepped transmission. To avoid overloading the clutch, the method determines a load-independent startup gear with which startup would occur under the present starting conditions without considering the current load state of the clutch and without complying with a load limit of the clutch. A load-specific startup gear is determined as the highest startup gear, with which during a startup under the present starting conditions, a predefined load limit of the clutch would be maintained with consideration given to the present load state of the clutch. The startup gear is the lowest of the load-independent startup gear and the at least one load-specific startup gear.
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RELATED APPLICATIONS
Reference is made to an application of the same assignee of even filing date herewith entitled "Photolytic Production of Hydrogen" wherein the basic photolytic processes are also discussed.
BACKGROUND OF THE INVENTION
The present invention relates in general to photo-electrolytic processes and is directed, more specifically, to the production of hydrogen and/or oxygen from water utilizing a photo-electrolytic process.
The concept of employing hydrogen as a fuel is attractive because it is abundant and nonpolluting. Unfortunately, although it is abundant it is not readily available in the molecular state and, in order for it to become a viable fuel satisfying significant future energy requirements, means for producing it in vast quantities in an economic manner will have to be identified and demonstrated.
Past technologies for the production of hydrogen, including the electrolysis of water or processing of fossil fuels, have typically required the expenditure of large amounts of energy usually from sources fueled by expendable materials.
In recent years some attention has been given to the production of hydrogen in closed-cycle, multistep, thermochemical processes for cracking water. However, the direct thermal decomposition of water requires temperatures in excess of 2500° K. Furthermore, separation of the products, hydrogen and oxygen, is extremely difficult.
The direct photodecomposition of water requires radiation in the ultraviolet spectral region at wavelengths well below 2000 A. However, suitable intense ultraviolet light sources are not readily available nor are the materials which are readily transparent to such ultraviolet radiation.
What is really required is a practical means of producing hydrogen in a process that does not involve the unrealistic expenditure of our natural nonregenerable resources.
SUMMARY OF THE INVENTION
The present invention involves a process for the production of hydrogen from water utilizing radiant energy within the visible light spectrum in a series of low-temperature photolytic or thermal and electrolytic reactions.
The overall reaction utilizes halogens, and an overall reaction describing one embodiment of the process may be expressed as:
Br.sub.2 + H.sub.2 O ⃡ H.sub.2 + Br.sub.2 + 1/2 O.sub.2
or
Br.sub.2 + I.sub.2 + H.sub.2 O ⃡ H.sub.2 + Br.sub.2 + I.sub.2 + 1/2 O.sub.2
individually, the preferred reactions are depicted as follows: ##EQU1##
The hydrogen and oxygen thus produced could be reacted in a fuel cell to provide power during peak demand periods.
There are many advantages to the invention and significant differences from the past technology including the following:
1) a source of high temperature heat is not required,
2) visible light is effective in promoting desired photolytic reactions such light being available from many sources including the sun,
3) optics or other concentrators are not required,
4) a large percentage of the total solar flux can be used to effect the reactions, and the products are easily separated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the apparatus used to verify the ability of visible light to produce the reaction:
Br.sub.2 (G) + H.sub.2 O(G) .sup.hv 2HBr(G) + 1/2 O.sub.2 (G)
fig. 2 is a graph of pressure versus time in the above reaction.
FIG. 3 is a graph of temperature versus time in the above reaction using the apparatus of FIG. 1, as hereinafter described.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Closed cycle processes are extremely attractive and such a process is herein described as a preferred embodiment. In the process intermediate species are regenerated without loss and the only pollutant is degraded heat.
In the first embodiment, hydrogen bromide is provided according to the reaction: ##EQU2##
In reaction (1), gaseous molecular bromine and water are allowed to react at approximately 373° K in the presence of radiation (3650-5350 A) to yield gaseous hydrogen bromide (HBr) and oxygen (O 2 ).
Hydrogen bromide is separated by dissolution in a HBr/H 2 O mixture up to a concentration of about 87% HBr/13% H 2 O (by weight). Since oxygen is relatively insoluble in water, the hydrogen bromide/oxygen separation is effected.
Hydrogen bromide is not readily dissociated at temperatures below approximately 1500° K and forms a constant boiling mixture with water at about 47% HBr which boils at 399° K. Distillation of the HBr/H 2 O mixture drives off HBr which is collected until the concentration of HBr in water reaches 47%.
In reaction (2) the hydrogen bromide is electrolytically decomposed during a period of off-peak power and the hydrogen together with the oxygen already available can be recombined as in a fuel cell (reaction 3) providing electricity in a peak power demand period. The advantage here over the direct electrolysis of water is that the hydrogen bromide can be electrolyzed with less energy expenditure. Furthermore, the recombination of the hydrogen and oxygen in a fuel cell can theoretically produce more electrical energy than that required for the hydrogen bromide electrolysis.
In a variation of the foregoing, the following reactions are utilized: ##EQU3##
In this variation, it will be seen that hydrogen bromide is photolytically produced as in the first embodiment. However, instead of electrolyzing the hydrogen bromide the collected HBr is allowed to react with iodine (I 2 ) (Reaction 1A) at 456° K in the presence of radiation (4300A-7400A) to yield gaseous hydrogen iodide (HI) and iodine monobromide (IBr), some unreacted HBr remaining.
Cooling the reaction mixture below the boiling point of the iodine monobromide permits the separation of the liquid IBr from the gaseous hydrogen iodide.
Iodine and bromine may be regenerated from the iodine monobromide by decomposition of the monobromide at a temperature of about 700° K or photolytically in the visible spectral region (Reaction 5).
The hydrogen iodide resultant from the reaction 1A operation is electrolytically decomposed yielding hydrogen and iodine (Reaction 4).
Recombination of the hydrogen and oxygen with the production of electrical power may then be affected, as previously discussed.
In the case of solar energy as the radiation source:
1. about 21 percent of the total solar flux is usable to effect reaction (1);
2. about 30 percent of the total solar flux is available to effect reaction (1A); and
3. about 30 percent of the total solar flux can be used for reaction (5).
The reaction sequence is not Carnot limited in the sense that photolytic dissociation does not depend on temperature as is the case with reactions associated with a Carnot cycle. Furthermore, the reactions depend only upon the photon flux (photons/cm 2 /sec.) thus, apparatus to effect a concentration of radiation is not required.
Solar energy is one readily available radiation source. Another radiation source capable of providing radiation of the desired wavelength is the plasma core reactor. A typical plasma core reactor radiates about 3 × 10 2 watt/cm 2 (effective black body radiating temperature of 4000° K.) at wavelengths between 3300A and 5300A. For radiating temperatures of 4000° K and 6000° K, approximately 25 percent and 45 percent, respectively, of that spectral flux is available for use in the bromine and iodine photodissociation reactions.
Verification of the reaction
, H.sub.2 O + Br.sub.2 .sup.hv 2HBr + 1/2 O.sub.2 (1)
was made utilizing the apparatus set forth in FIG. 1.
This apparatus was a 6.4 cm diameter by 30 cm. long reaction cell (20) having Pyrex (22 and 24) windows fused to both ends.
A tungsten-iodine filament lamp (21) was utilized as the source of radiation.
Pressure and temperature traces for the 100-minute time period of the experiment are shown in FIGS. 2 and 3 respectively, as functions of time. During the period of irradiation (about 48 minutes), a pressure increase was noted; the cell pressure increased from 0.36 atm to about 0.52 atm (FIG. 2). The cell pressure was also observed to increase slightly over the next 30-minute period after the radiation source had been extinguished. The pressure during this period increased from about 0.52 atm to approximately 0.56 atm and remained effectively constant thereafter until conclusion of the experiment (about 100 minutes).
Temperature traces for the two thermocouples 26 and 28 as a function of time for the corresponding time span of the experiment are illustrated in FIG. 3.
The data of FIG. 3 indicate an average decrease in cell temperature over the time span of the experiment. The straight line curves in FIG. 3 are least squares determinations of the temperature data for the two thermocouples.
The increasing cell pressure with a corresponding decrease in temperature indicates that a reaction between water and bromine had occurred with an attendant increase in pressure.
Temperature and pressure monitoring were accomplished by means of the chromel-alumel thermocouples and an absolute pressure transducer (30).
Two 100 ml flasks 32 and 34 were installed on the cell and served as reservoirs for liquid water and bromine as shown in FIG. 1. In addition a vacuum pump 36 was installed to permit evacuation of the cell as required. The cell and various components were heated with variac-controlled, electrical tapes 38.
The entire apparatus was placed in a hood because of the corrosiveness of bromine.
Equi-molar quantities of liquid water and bromine were measured with hypodermic syringes and introduced into the 100 ml reservoirs. The quantities were such that total evaporation of both the water and bromine would yield a cell pressure of about 0.5 atm prior to reaction. The liquids in the reservoirs were sealed off from the reaction cell by means of stopcocks 40 and 42. Subsequently, the liquids (water and bromine) were frozen out with liquid nitrogen and the entire system (reaction cell and reservoirs) evacuated with the vacuum pump. After evacuation of the system, the system was isolated from the pump and the water and bromine were allowed to thaw. Finally, the cell and reservoirs were heated to about 400° K. At 400° K, the cell pressure attained a value of about 0.36 atm prior to irradiation. Failure to attain a predetermined pressure of 0.5 atm was due largely to inability to accurately measure the volume of liquid bromine introduced into the system initially.
After attainment of equilibrium with respect to temperature and pressure, irradiation of the reaction mixture was initiated with concurrent monitoring of cell pressure and temperature. The reaction mixture was irradiated for about 48 minutes. Pressure and temperature were monitored for a total of approximately 100 minutes.
Table I illustrates the characteristics of various species discussed herein.
TABLE I__________________________________________________________________________Dissociation Melting BoilingEnergy Point Point SolubilitySpeciesev nm ° K(° C) ° K(° C) g/100 g H.sub.2 O__________________________________________________________________________I.sub.21.542 804 387 (114) 456 (183) 0.034Br.sub.21.971 629 265.7 (-7.3) 331.8 (58.8) 15.5Cl.sub.22.475 501 171 (-102) 239.3 (-33.7) 0.64HI 3.056 406 222.2 (-50.8) 237.6 (-35.4) ˜2.5HBr 3.754 330 184.5 (-88.5) 206 (-67) 194HCl 4.430 280 161 (-112) 189.3 (-83.7) 69.8H.sub.24.553 272 18.8 (-254.2) 20.2 (-252.8) negl.O.sub.25.080 244 54.6 (-218.4) 90 (-183.0) negl.H.sub.2 O5.12 242 273 (0) 373 (100) --__________________________________________________________________________
Although the invention has been shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes and omissions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
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Hydrogen and oxygen are produced from water in a process involving the photodissociation of molecular bromine with radiant energy at wavelengths within the visible light region and a subsequent electrolytic dissociation of hydrogen halides.
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RELATED APPLICATIONS
[0001] This application is a non-provisional of and claims priority to and the benefit of U.S. Provisional Patent Application No. 61/539,171, titled “Methods Of Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors And A Downhole Broadband Transmitting System,” filed on Sep. 26, 2011, and is related to U.S. patent application Ser. No. ______, filed on ______, titled “Apparatus and Program Product for Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors and a Downhole Broadband Transmitting System”; U.S. patent application Ser. No. ______, filed on ______, titled “Apparatus and Program Product for Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors and Telemetry System”; U.S. patent application Ser. No., ______, filed on ______, titled “Methods of Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors and Telemetry System”; U.S. patent application Ser. No., ______, filed on ______, titled “Apparatus for Evaluating Rock Properties While Drilling Using Drilling Rig-Mounted Acoustic Sensors”; and U.S. patent application Ser. No., ______, filed on ______, titled “Methods for Evaluating Rock Properties While Drilling Using Drilling Rig-Mounted Acoustic Sensors”; U.S. Provisional Patent Application No. 61/539,165, titled “Apparatus And Program Product For Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors And A Downhole Broadband Transmitting System,” filed on Sep. 26, 2011; U.S. Provisional Patent Application No. 61/539,201, titled “Apparatus For Evaluating Rock Properties While Drilling Using Drilling Rig-Mounted Acoustic Sensors,” filed on Sep. 26, 2011; U.S. Provisional Patent Application No. 61/539,213, titled “Methods For Evaluating Rock Properties While Drilling Using Drilling Rig-Mounted Acoustic Sensors,” filed on Sep. 26, 2011; U.S. Provisional Patent Application No. 61/539,242 titled “Apparatus And Program Product For Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors And Telemetry System,” filed on Sep. 26, 2011; and U.S. Provisional Patent Application No. 61/539,246 titled “Methods Of Evaluating Rock Properties While Drilling Using Downhole Acoustic Sensors And Telemetry System,” filed on Sep. 26, 2011, each incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates in general to hydrocarbon production, and more particularly, to identifying rock types and rock properties in order to improve or enhance drilling operations.
[0004] 2. Description of the Related Art
[0005] Measuring rock properties during drilling in real time can provide the operator the ability to steer a drill bit in the direction of desired hydrocarbon concentrations. In current industrial practice and prior inventions, either resistivity or sonic logging while drilling (LWD) tools are employed to guide the drill bit during horizontal or lateral drilling. The center of these techniques is to calculate the locations of the boundary between the pay zone and the overlying rock (upper boundary), and the boundary between the pay zone and underlying rock at the sensors location. The drill bit is steered or maintained within the pay zone by keeping the drill string, at the sensors position, in the middle, or certain position between the upper and lower boundaries of the pay zone. The conventional borehole acoustic telemetry system, which transmits data at low rate (at about tens bit per second), is employed to transmit the measured data to surface.
[0006] Since the sensors are located 30-50 feet behind the drill bit, theses conventional LWD steering tools only provide data used in steering the drill bit 30-50 feet behind the drill bit. As the result, it is only after the 30-50 feet that the operator finds out if the selected drilling path is or is not the desired one. Therefore, these tools are not true real-time tools.
[0007] Some newer types of systems attempt to provide data at the drill bit, at-real-time, while still utilizing conventional borehole telemetry systems (having a relatively slow bit rate). Such systems, for example, are described as including a downhole processor configured to provide downhole on-site processing of acoustic data to interpret the lithologic properties of the rock encountered by the drill bit through comparison of the acoustic energy generated by the drill bit during drilling with predetermined bit characteristics generated by rotating the drill bit in contact with a known rock type. The lithologic properties interpreted via the comparison are then transmitted to the surface via the conventional borehole telemetry system. Although providing data in a reduced form requiring only a bit rate speed, as such systems do not provide raw data real-time which can be used for further analysis, it is nearly impossible to construct additional interpretation models or modify any interpretation models generated by the downhole processor.
[0008] Some newer types of borehole data transmitting systems utilize a dedicated electronics unit and a segmented broadband cable protected by a reinforced steel cable positioned within the drill pipe to provide a much faster communication capability. Such systems have been employed into conventional LWD tools to enhance the resolution of the logged information. However the modified tools still measures rock properties at the similar location which is 30-50 feet behind the drill bit.
[0009] Accordingly, recognized by the inventor is the need for apparatus, computer readable medium, program code, and methods of identifying rock properties in real-time during drilling, and more particularly, methods which include positioning acoustic sensors adjacent the drill bit to detect drill sounds during drilling operations, pushing raw acoustic sensor data to a surface computer over a broadband transmitting system, receiving the raw acoustic sensor data, and deriving the rock type and/or evaluating the properties of the rocks in real-time utilizing the raw acoustic sensor data.
SUMMARY OF THE INVENTION
[0010] In view of the foregoing, various embodiments of the present invention advantageously provide apparatus, computer readable medium, program code, and methods of identifying rock types and rock properties of rock that is currently in contact with an operationally employed drilling bit, which can be used in real-time steering of the drilling bit during drilling. Various embodiments of the present invention provide methods which include positioning acoustic sensors adjacent the drill bit to detect drill sounds during drilling operations, pushing raw acoustic sensor data to a surface computer over a broadband transmitting system, receiving the raw acoustic sensor data, and deriving the rock type and/or evaluating the properties of the rocks in real-time utilizing the raw acoustic sensor data.
[0011] According to various embodiments of the present invention, a surface computer/processor receives the raw acoustic sensor data. Utilizing the raw acoustic sensor data, the computer can advantageously function to derive a frequency distribution of the acoustic sensor data, derive acoustic characteristics from the raw acoustic data, and determine petrophysical properties of rock from the raw acoustic sensor data. The acoustic characteristics can advantageously further be used to identify the lithology type of the rock encountered by the drill bit, to determine the formation boundary, to determine an optimal location of the casing shoe, among other applications. According to various embodiments of the present invention, to determine petrophysical properties of the rock directly from the raw acoustic sensor data (generally after being converted into the frequency domain and filtered), a petrophysical properties evaluation algorithm can be derived from acoustic sensor data and correspondent petrophysical properties of formation samples.
[0012] Various embodiments of a method of identifying rock properties of rock in real-time during operational drilling, to include identifying lithology type and other petrophysical properties, can include the deployment, installation, and/or positioning of both conventional components and additional/enhanced acoustic components. Some primary conventional components include a drill string containing a plurality of drill pipes each having an inner bore, a drill bit connected to the downhole end of the drill string, and a top drive system for rotating the drill string having both rotating and stationary portion. The additional/acoustic components can include a downhole sensor subassembly connected to and between the drill bit and the drill string, acoustic sensors (e.g. accelerometer, measurement microphone, contact microphone, hydrophone) attached to or contained within the downhole sensor subassembly adjacent the drill bit and positioned to detect drill sounds during drilling operations. The additional components can also include a broadband transmitting system operably extending through the inner bore of each of the plurality of drill pipes and operably coupled to the acoustic sensors through the downhole data transmitting interface position therewith, a surface data transmitting interface typically connected to a stationary portion of the top drive system, a surface data acquisition unit connected to the surface data transmitting interface, and a surface computer operably coupled to the downhole data transmitting interface through the data acquisition unit, the surface data transmitting interface, and the broadband transmitting system.
[0013] Various embodiments of the method can also include both computer employable steps (operations), as described later with respect to the operations performed by various featured apparatus/program code, and various non-computer implemented steps which provide substitutable replacements for the featured computer implemented steps, in conjunction with additional non-computer implemented steps as described below and/or as featured in the appended claims. Examples of various embodiments of the method are described below.
[0014] According to an embodiment of a method of analyzing properties of rock in a formation in real-time during drilling, the method can include the steps of sending sampling commands to the data acquisition unit and receiving raw acoustic sensor data from a surface data interface in communication with a communication medium further in communication with a downhole data interface operably coupled to a plurality of acoustic sensors. The method can also include various processing steps which include deriving a frequency distribution of the raw acoustic sensor data, deriving a plurality of acoustic characteristics including mean frequency and normalized deviation of frequency from the raw acoustic sensor data utilizing, for example, an acoustics characteristics evaluation algorithm, and/or deriving petrophysical properties from the raw acoustic sensor data utilizing, for example, a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.
[0015] According to an embodiment of the method, the step of deriving a frequency distribution of the acoustic data from the raw acoustic sensor data includes transforming the raw acoustic sensor data into the frequency domain (e.g., employing a Fast Fourier Transform (FFT)), and filtering the transformed data.
[0016] According to an embodiment of the method, the step of deriving the plurality of acoustic characteristics from the raw acoustic sensor data can include providing the acoustic characteristics evaluation algorithm and comparing the mean frequency, the normalized deviation of frequency, the mean amplitude, the normalized deviation of amplitude, and apparent power for the rock undergoing drilling with the mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power for a plurality of rock samples having different known lithologies according to a first configuration, or comparing only part of the acoustic characteristics, such as the mean frequency and the normalized deviation of frequency of the rock undergoing drilling with the same type of acoustic characteristics of a plurality of rock samples having different known lithologies according to another configuration. The method can also include identifying lithology type of the rock undergoing drilling, determining a location of a formation boundary encountered during drilling, and/or identifying an ideal location for casing shoe positioning, among others.
[0017] According to an exemplary implementation, the mean frequency and normalized deviation of frequency are examined together to determine an amount of correlation of the acoustic characteristics associated with the rock undergoing drilling and the acoustic characteristics associated with the rock samples. Also or alternatively, the mean frequency and the mean amplitude can be examined together and/or with normalized deviation of frequency and/or normalized deviation of amplitude and apparent power, or a combination thereof. The step of comparing can beneficially be performed substantially continuously during drill bit steering in order to provide enhanced steering ability.
[0018] According to an embodiment of the method, the step of deriving petrophysical properties from the raw sensor data can include deriving a bit-specific petrophysical properties evaluation algorithm for use in evaluating the received signals. The derivation of the algorithm can include collecting petrophysical properties data describing one or more petrophysical properties of rock for a plurality of formation samples and correspondent acoustic data for a preselected type of drill bit and processing the collected acoustic data to produce filtered FFT data. The algorithm derivation can also include determining one or more relationships between features of the filtered FFT data and correspondent one or more petrophysical properties of rock describing petrophysical properties of a plurality of formation samples, e.g., utilizing mathematical modeling techniques such as, multiple regression analysis, artificial neural network modeling, etc. The algorithm derivation can also include coding the determined relationships into computer program code defining the bit-specific petrophysical properties evaluation algorithm. The derived algorithm can then be used in predicting one or more petrophysical properties of the rock undergoing drilling real-time responsive to filtered data associated with raw acoustic sensor data produced in response to the drilling.
[0019] According to another embodiment of the method, the step of deriving petrophysical properties from the raw sensor data can also or alternatively include deriving a bit-independent petrophysical properties evaluation algorithm. The derivation of the algorithm can include collecting petrophysical properties data describing one or more petrophysical properties of rock for a plurality of formation samples and correspondent acoustic data for a plurality of different types of drill bits, processing the collected acoustic data to produce filtered FFT data, and determining bit-type independent features of the filtered FFT data. The algorithm derivation can also include determining one or more relationships between the bit-type independent features of the filtered FFT data and correspondent one or more petrophysical properties of the rock, e.g., using mathematical modeling techniques, such as artificial neural network modeling, etc., to provide a bit-independent evaluation methodology. The algorithm derivation can also include coding the determined relationships into computer program code defining the bit-independent petrophysical evaluation properties algorithm. Correspondingly, the method can include employing the derived petrophysical properties evaluation algorithm to predict one or more petrophysical properties of the rock undergoing drilling real-time responsive to filtered data associated with raw acoustic sensor data produced in response to the drilling, as described, for example, with respect to the prior described bit-specific evaluation methodology.
[0020] According to various embodiments of the present invention, apparatus for analyzing properties of rock in a formation in real-time during drilling are also provided. An example of an embodiment of such an apparatus can include a drill string containing a plurality of drill pipes each having an inner bore, a drill bit connected to the downhole end of the drill string, and a top drive system for rotating the drill string having both rotating and stationary portion. The apparatus can also include a downhole sensor subassembly connected to a rotating portion of the system, such as, for example, to and between the drill bit and the drill string, acoustic sensors (e.g. accelerometer, measurement microphone, contact microphone, hydrophone) attached to or contained within the downhole sensor subassembly adjacent the drill bit and positioned to detect drill sounds during drilling operations. The apparatus can further include a broadband transmitting system operably extending through the inner bore of each of the plurality of drill pipes and operably coupled to the acoustic sensors through the downhole data transmitting interface position therewith, a surface data transmitting interface typically connected to a stationary portion of the top drive system, a data acquisition unit in communication with the surface data transmitting interface, and a surface computer operably coupled to the downhole data transmitting interface through surface acquisition unit, the surface data transmitting interface, and the broadband transmitting system.
[0021] According to an embodiment of the apparatus, the computer includes a processor, memory in communication with the processor, and petrophysical properties analyzing program, which can adapt the computer to perform various operations. The operations can include, for example, sending sampling commands to the data acquisition unit, receiving raw acoustic data from the downhole data transmitting interface, processing the received raw acoustic sensor data—deriving a frequency distribution of the acoustic data from the raw acoustic data, employing an acoustics characteristics evaluation algorithm to thereby derive acoustic characteristics from the raw acoustic sensor data (e.g., via analysis of the processed acoustics data), and employing a petrophysical properties evaluation algorithm to thereby derive petrophysical properties of rock undergoing drilling, real-time, from the acoustics data.
[0022] According to an embodiment of the apparatus, the acoustic characteristics evaluation algorithm evaluates filtered Fast Fourier Transform data for acoustic characteristics. The acoustic characteristics can include mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power. These characteristics can be predetermined for rock samples having a known lithology type and/or petrophysical properties, and thus, can be used to identify lithology type and other properties by comparing such characteristics of the acoustic data received during drilling to that determined for the rock samples. According to another embodiment of the apparatus, the computer uses the derived acoustic characteristics to determine formation boundaries based on real-time detection of changes in the lithology type of the rock being drilled and/or petrophysical properties thereof.
[0023] According to an exemplary configuration, the petrophysical properties analyzing program or separate program code functions derive a “bit specific” or “bit independent” petrophysical properties evaluation algorithm. Similarly, the derived bit specific or bit independent petrophysical properties evaluation algorithm evaluates filtered Fast Fourier Transform data for petrophysical properties. This petrophysical property data can advantageously be applied by other applications to include real-time lithology type identification, formation boundary determination, casing shoe position fine-tuning, etc.
[0024] According to an embodiment of the present invention, the petrophysical properties analyzing program can be provided either as part of the apparatus or as a standalone deliverable. As such, the petrophysical properties analyzing program can include a set of instructions, stored or otherwise embodied on a non-transitory computer readable medium, that when executed by a computer, cause the computer to perform various operations. These operations can include the operation of receiving raw acoustic sensor data from a surface data interface in communication with a communication medium that is further in communication with a downhole data interface operably coupled to a plurality of acoustic sensors. The operations can also include the processing operations of deriving a frequency distribution of the raw acoustic sensor data, deriving a plurality of acoustic characteristics including mean frequency and normalized deviation of frequency from the raw acoustic sensor data, and/or deriving petrophysical properties from the raw acoustic sensor data utilizing a derived petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.
[0025] According to an embodiment of the petrophysical properties analyzing program, the operation of deriving a frequency distribution of the acoustic data from the raw acoustic sensor data includes transforming the raw acoustic sensor data into the frequency domain (e.g., employing a Fast Fourier Transform), and filtering the transformed data.
[0026] According to an embodiment of the petrophysical properties analyzing program, the operation of deriving the plurality of acoustic characteristics from the raw acoustic sensor data can include comparing the mean frequency, the normalized deviation of frequency, the mean amplitude, the normalized deviation of amplitude, and apparent power for the rock undergoing drilling with the mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power for a plurality of rock samples having different known lithologies according to a first configuration, or comparing only part of the acoustic characteristics, such as the mean frequency and the normalized deviation of frequency of the rock undergoing drilling with the same type of acoustic characteristics of a plurality of rock samples having different known lithologies according to another configuration. The operations can also include identifying lithology type of the rock undergoing drilling, determining a location of a formation boundary encountered during drilling, and/or identifying an ideal location for casing shoe positioning, among others.
[0027] According to an exemplary implementation, the mean frequency and normalized deviation of frequency are examined together to determine an amount of correlation of the acoustic characteristics associated with the rock undergoing drilling and the acoustic characteristics associated with the rock samples. Also or alternatively, the mean frequency and the mean amplitude can be examined together and/or with the normalized deviation of frequency or apparent power, or a combination thereof. The operation of comparing can beneficially be performed substantially continuously during drill bit steering in order to provide enhanced steering ability.
[0028] According to an embodiment of the petrophysical properties analyzing program employing a bit-specific evaluation methodology, the operation of deriving petrophysical properties from the raw acoustic sensor data can include deriving a bit-specific petrophysical properties evaluation algorithm. The derivation of the algorithm can include collecting petrophysical properties data describing one or more petrophysical properties of rock for a plurality of formation samples and correspondent acoustic data for a preselected type of drill bit, processing the collected acoustic data to produce filtered FFT data, and determining one or more relationships between features of the filtered FFT data and correspondent one or more petrophysical properties of rock describing petrophysical properties of the plurality of formation samples. This can be accomplished, for example, by utilizing mathematical modeling techniques such as, multiple regression analysis, such as artificial neural network modeling, etc. The derivation of the algorithm can also include coding the determined relationships into computer program code defining the petrophysical properties evaluation algorithm. The operations can correspondingly include employing the derived petrophysical properties evaluation algorithm to predict one or more petrophysical properties of the rock undergoing drilling real-time responsive to filtered data associated with raw acoustic sensor data produced in response to the drilling.
[0029] According to an embodiment of the petrophysical properties analyzing program employing a bit-independent evaluation methodology, the petrophysical properties evaluation algorithm derivation can also or alternatively include collecting petrophysical properties data describing one or more petrophysical properties of rock for a plurality of formation samples and correspondent acoustic data for a plurality of different types of drill bits, processing the collected acoustic data to produce filtered FFT data, determining bit-type independent features of the filtered FFT data, and determining one or more relationships between the bit-type independent features of the filtered FFT data and correspondent one or more petrophysical properties of the rock to provide a bit-independent evaluation methodology. The algorithm derivation can also include coding the determined relationships into computer program code defining a bit-independent petrophysical properties evaluation algorithm. The operations can correspondingly include employing the derived petrophysical properties evaluation algorithm to predict one or more petrophysical properties of the rock undergoing drilling real-time responsive to filtered data associated with raw acoustic sensor data produced in response to the drilling, as described, for example, with respect to the prior described bit-specific evaluation methodology.
[0030] Various embodiments of the present invention advantageously supply a new approach for a much better drilling steering. Various embodiments of the present invention provide apparatus and methods that supply detailed information about the rock that is currently in contact with the drilling bit, which can be used in real-time steering the drilling bit. That is, various embodiments of the present invention advantageously provide an employable methodology of retrieving a sufficient level of information so that the driller always knows the rock he is drilling, so that the drilling bit can be steered to follow the desire path more accurately than conventionally achievable. In comparison with conventional drilling steering tools, the real-time data provided by various embodiments of the present invention advantageously allow the driller to drill smoother lateral or horizontal wells with better contact with the production zone, to detect formation boundaries in real-time, and to detect the fractured zones in real-time, and to perform further analysis on raw sensor data, if necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] So that the manner in which the features and advantages of the invention, as well as others which will become apparent, may be understood in more detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which form a part of this specification. It is to be noted, however, that the drawings illustrate only various embodiments of the invention and are therefore not to be considered limiting of the invention's scope as it may include other effective embodiments as well.
[0032] FIGS. 1A-1B is a partial perspective view and partial schematic diagram of a general architecture of an apparatus for identifying rock properties in real-time during drilling according to an embodiment of the present invention;
[0033] FIG. 2 is a schematic diagram showing a data processing procedure performed by a computer program according to an embodiment of the present invention;
[0034] FIG. 3 is a schematic diagram illustrating major components of a data preprocess module according to an embodiment of the present invention;
[0035] FIGS. 4A-4B are graphs illustrating examples of a frequency distribution of two types of carbonate according to an embodiment of the present invention;
[0036] FIG. 5 is a graph illustrating a three dimensional depiction of the frequency distribution in correlation with various lithography types according to an embodiment of the present invention;
[0037] FIG. 6 is a graph illustrating a comparison of mean frequency and normalized deviation of frequency correlated with a plurality of lithology types according to an embodiment of the present invention;
[0038] FIG. 7 is a schematic flow diagram illustrating steps for forming a petrophysical properties evaluation algorithm for a particular type of drill bit according to an embodiment of the present invention; and
[0039] FIG. 8 is a schematic flow diagram illustrating steps for forming a drill bit independent petrophysical properties evaluation algorithm according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0040] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, which illustrate embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated 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. Like numbers refer to like elements throughout. Prime notation, if used, indicates similar elements in alternative embodiments.
[0041] When drilling into different lithologies or the same lithology with different properties (e.g., porosity, water saturation, permeability, etc.) the generated acoustic sounds emanating from the drill bit when drilling into rock, are distinctly different. The sounds, termed as drilling acoustic signals hereafter, transmit upward along the drill string. According to various embodiments of the present invention, a sensor subassembly containing acoustic sensors is positioned above the drill bit and connected to the above drill string. The drilling acoustic signals transmit from the drill bit to the sensor subassembly and are picked up by the acoustic sensors. The drilling acoustic signals received by the sensors are transmitted (generally after amplification) to surface by a borehole transmitting system which can include various components such as, for example, a downhole data interface, a broadband conductor, a surface data interface, etc. On the surface, the received acoustic signals are transformed by a data processing module into the frequency domain using, for example, a Fast Fourier Transformation (FFT) to generate FFT data (primarily the frequency and amplitude data). Some acoustic characteristics are derived directly from the FFT data. The frequency distribution and acoustic characteristics, for example, can be used immediately in some applications, such as lithology type identification and formation boundary determination. The FFT data can be further analyzed using a calibrated mathematical model, for the lithology type and petrophysical properties, which have wider applications than the direct results (frequency distribution and acoustic characteristics).
[0042] Where conventional measurement-while-drilling tools are typically located 30 to 50 feet behind the drill bit, beneficially, a major advantage of approaches employed by various embodiments of the present invention is that such approaches can derive information about lithologies from a position located at the cutting surface of the drill bit to provide such information to the operator steering the drill bit, in real time. This advantage makes aspects of various embodiments of the present invention ideal in the application of horizontal and lateral well drill steering, locating the relative position for setting the casing shoe, detecting fractured zones, and interpreting rock lithologies and petrophysical properties in real time.
[0043] FIGS. 1A-1B schematically show the setup of an exemplary apparatus for identifying rock properties in real-time during drilling 100 . Acoustic sensors 102 are connected to a downhole data “transmitting” interface 103 . According to the exemplary configuration, both are contained in a sensor subassembly 104 , which is positioned above a drill bit 101 and connected to a drill string 117 . In operation, the drilling acoustic signals are generated when the drill bit 101 bites rocks at the bottom of a borehole 118 during the drilling process.
[0044] Different acoustic sensors 102 may be used, e.g. accelerometer, measurement microphone, contact microphone, and hydrophone. According to the exemplary configuration, at least one, but more typically each acoustic sensor 102 either has a built-in amplifier or is connected directly to an amplifier (not shown). The drilling acoustic signals picked up by the acoustic sensors 102 are amplified first by the amplifier before transmitted to the downhole data interface 103 .
[0045] From the downhole data interface 103 , acoustic signals are transmitted to a surface data “transmitting” interface 106 through a borehole broadband data transmitting system 105 . Currently, one commercially available broadband data transmitting system, NOV™ IntelliServ®, can transmit data at the rate of 1000,000 bit/s. A study indicated that with two acoustic sensors 102 at normal working sampling rate of 5 seconds per sample, the required data transmitting rate was about 41,000 bits/s. Therefore, the NOV™ IntelliServ® borehole broadband data transmitting system is an example of a broadband communication media capable of transmitting acoustic signals data for at least four acoustic sensors 102 to surface directly from a downhole data interface 103 .
[0046] According to the exemplary configuration, the surface data interface 106 is located at the stationary part of the top drive 107 . From the surface data interface 106 , the acoustic signals are further transmitted to a data acquisition unit 110 through an electronic cable 108 , which is protected inside a service loop 109 . The data acquisition unit 110 is connected to a computer 124 through an electronic cable 126 . The data acquisition unit 110 samples the acoustic signal in analog format and then converts the analog acoustic signals into digit data in FIG. 2 .
[0047] Referring to FIGS. 1 and 2 , the digitized data 111 is read by a computer program 112 (e.g., a petrophysical properties analyzing program), installed in memory 122 accessible to processor 123 of computer 124 . The computer program 112 analyzes the digitized data 111 to derive a frequency distribution 113 , acoustic characteristics 114 , and petrophysical properties 115 of the rock undergoing drilling. The respective results, e.g., frequency distribution 113 , acoustic characteristics 114 , and petrophysical properties 115 , can be used in various applications 116 to include lithology identification, drill bit steering, formation boundary identification, among others. Such data along with rock sample data, rock modeling data, etc. can be stored in database 125 stored in either internal memory 122 or an external memory accessible to processor 123 .
[0048] Note, the computer 124 can be in the form of a personal computer or in the form of a server or server farm serving multiple user interfaces or other configurations known to those skilled in the art. Note, the computer program 112 can be in the form of microcode, programs, routines, and symbolic languages that provide a specific set or sets of ordered operations that control the functioning of the hardware and direct its operation, as known and understood by those skilled in the art. Note also, the computer program 112 , according to an embodiment of the present invention, need not reside in its entirety in volatile memory, but can be selectively loaded, as necessary, according to various methodologies as known and understood by those skilled in the art. Still further, at least portions of the computer program 112 can be stored in memory of the sensor subassembly 104 when so configured.
[0049] Referring to FIG. 3 , according to the exemplary configuration, the digitized data 111 needs to be preprocessed before any use. According to the exemplary configuration, this is accomplished by a subroutine program referred to as data preprocess module 200 . As illustrated in the figure, the digitized data is transformed into Fast Fourier Transform (FFT) data 202 by a FFT 201 . The FFT data 202 is then filtered by a filter 203 to remove some low/high frequency and/or low amplitude data points, generated from other sources, i.e. not from the bit cutting into the rocks. The filtered FFT data 301 is then used in the various part of data process. Note. the filtered FFT data 301 is relabeled as 403 in FIGS. 7 . and 503 in FIG. 8 . Note also, the digitized data 111 is relabeled as 402 in FIGS. 7 , and 502 in FIG. 8 .
[0050] Major components and functions of the computer program 112 according to an exemplary configuration are detailed in FIG. 2 . According to the exemplary configuration, there are four modules (components) in the computer program 112 : a data preprocess module 200 , a data sampling module 210 , an acoustic characteristics evaluation algorithm 302 , and a petrophysical properties evaluation algorithm 303 . The sampling module 210 sends sampling commands 127 , such as sampling rate, to the data acquisition unit 110 for data sampling control. The main part of the filtered FFT data 301 is a frequency distribution 113 , which is the frequency and amplitude information of a sampled acoustic signal. Two examples of such signal are shown in FIGS. 4A and 4B . FIG. 4A illustrates the frequency distribution for a limestone and FIG. 4B illustrates the frequency distribution for limestone dolomite. A review of the frequency distribution of the two different types of carbonates illustrates how the frequency distribution can be used directly to distinguish lithologies.
[0051] According to the exemplary configuration, the frequency distribution 113 can be used directly in some applications, such as lithology type identification, formation boundaries determination, etc., represented by example at 116 . The frequency distribution 113 can be plotted into time-frequency spectrum which can be used directly in some applications, such as lithology type identification, formation boundaries determination, etc., represented by example at 116 .
[0052] An example of such signal displaying diagram is shown in FIG. 5 , which illustrates results of a laboratory experiment showing different lithologies have different frequency spectrums and lithology boundaries can be determined using the diagram. In FIG. 5 , the color represents amplitude, with color normally displayed as red being highest (the intermixed color mostly concentrated just below the 4000 Hz range in this example) and the color normally displayed as blue being the lowest (the more washed out color in this example).
[0053] According to the exemplary configuration, an acoustic characteristics evaluation algorithm 302 evaluates the filtered FFT data 301 for select acoustic characteristics, such as, for example, mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude, and apparent power. These acoustic characteristics for an acoustic signal sample are defined as follows:
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[0000] wherein:
μ f —mean frequency, Hz, σ f — N —normalized deviation of frequency, Hz, μ A —mean amplitude, the unit depending on the type of acoustic sensor used in the measurement, σ A — N —normalized deviation of amplitude, the unit depending on the type of acoustic sensor used in the measurement, P a —apparent power, the unit depending on the type of acoustic sensor used in the measurement, f i —frequency of the i th point of the acoustic signal sample, Hz, A i —amplitude of the i th point of the acoustic signal sample, the unit depending on the type of acoustic sensor used in the measurement, and n—number of data points of the acoustic signal sample.
[0062] The mean frequency and the normalized deviation of frequency characterize the frequency distribution, while the mean amplitude and the normalized deviation of amplitude characterize the loudness level of the drilling sound. Apparent power represents the power of the acoustic signals. In the evaluation, these characteristics can be calculated within the whole range or a partial range of the frequency of the acoustic samples. The range is selected to achieve the maximum difference of these characteristics among different lithologies.
[0063] The derived acoustic characteristics 114 can be used directly for certain applications, such as lithology type identification, formation boundary determination represented by example at 116 ′. FIG. 6 illustrates results of a laboratory experiment showing that the mean frequency and normalized deviation of frequency correlated well with different lithology types.
[0064] According to an exemplary embodiment of the present invention, the mean frequency, the normalized deviation of frequency, the mean amplitude, the normalized deviation of amplitude, and/or the apparent power of the rock undergoing drilling can be compared with a corresponding mean frequency, normalized deviation of frequency, mean amplitude, normalized deviation of amplitude and/or apparent power of a plurality of rock samples having different known lithologies, to thereby determine an amount of correlation of the acoustic characteristics associated with the rock undergoing drilling and the acoustic characteristics associated with the rock samples. Responsively, the lithology type of the rock undergoing drilling can be determined.
[0065] FIGS. 7 and 8 illustrate examples of the construction of two types of petrophysical properties evaluation algorithms 303 : one designed for a particular type of drill bit shown at 303 A and the other designed to be drill bit type independent shown at 303 B. Unlike the FFT 201 and the acoustic characteristics evaluation algorithm 302 , which are based on known mathematical equations, the petrophysical properties evaluation algorithm 303 is based on mathematical models, which are to be built utilizing acoustic data and petrophysical properties according to an exemplary configuration.
[0066] FIG. 7 illustrates the procedure for constructing a “Petrophysical Properties Evaluation Algorithm” for a particular type of drill bit. According to the exemplary configuration, datasets of petrophysical properties 401 and correspondent digitized acoustic data 402 for a particular drill bit are collected. The digitized acoustic data 402 is preprocessed by the data preprocess module 200 (referred to in FIG. 2 ) to produce the filtered FFT data 403 . The relationships 405 between filtered FFT data 403 and petrophysical properties 401 are constructed (step 404 ) using suitable mathematical modeling techniques, such as, multiple regression analysis, artificial neural networks modeling. Once relationships 405 between the filtered FFT data 403 and petrophysical properties 401 are constructed, the relationships are coded (step 406 ) to produce a computer program, module, subroutine, object, or other type of instructions to define the “petrophysical properties evaluation algorithm” 303 A. The algorithm 303 A is then available to be used in the computer program 112 to predict the petrophysical properties from drilling acoustic signals for the particular drill bit type.
[0067] FIG. 8 illustrates the procedure for constructing a drill bit type independent “Petrophysical Properties Evaluation Algorithm” 303 B. The datasets of petrophysical properties 501 and the correspondent acoustic data 502 measured from different types of drill bit are collected. The acoustic data 502 is preprocessed by the data preprocess module 200 (e.g., the module referred to FIGS. 2 and 3 ) to produce the filtered FFT data 503 . Bit type independent features 505 of the filtered FFT data 503 are then determined by comparing the filtered FFT data of different types of drill bit and the correspondent petrophysical properties 501 (step 504 ). Features which have weakest correlation with the drill bit types and strong correlation with the petrophysical properties are the bit-type independent ones. The relationships 507 between the petrophysical properties 501 and the bit type independent features 505 are constructed (step 506 ) using suitable mathematical modeling techniques, such as, for example, multiple regression analysis, artificial neural networks modeling, among others. The constructed relationships 507 are then coded (step 508 ) into a computer program, module, subroutine, object, or other type of instructions to define the “petrophysical properties evaluation algorithm” 303 B. The algorithm 303 B is then available to be used in the computer program 112 to predict the petrophysical properties from drilling acoustic signals.
[0068] Application of the Results from the Processed Acoustic Signal.
[0069] One direct result is the frequency distribution 113 ( FIG. 2 ), which may be used directly in lithology type identification, formation boundary determination. FIGS. 4A and 4B , for example, show the frequency distribution of two different types of carbonates. The figures illustrate that the frequency distribution can be used in the lithology type identification from matching a detective frequency distribution with a frequency distribution of a rock of known lithography type.
[0070] FIG. 6 demonstrates the feasibility of using acoustic characteristics 114 ( FIG. 2 ) to derive lithology information. In FIG. 6 , mean frequency and normalized deviation were calculated from FFT data of the drilling sounds of a sample corer drilling into cores of different lithologies. The figure demonstrates how the lithology types can be distinguished by the combination of the two characteristics: mean frequency and the normalized deviation of frequency. If mean amplitude and the normalized deviation of the amplitude are also used, an even better result may be achieved. The figure also inherently demonstrates that formation boundaries can be determined from acoustic characteristics. FIGS. 7 and 8 demonstrate the feasibility of building a petrophysical properties evaluation algorithm 303 ( FIG. 2 ) which can be used to evaluate processed forms of the sound generated by operationally engaging the drilling bit with the rock being drilled.
[0071] Various embodiments of the present invention provide several advantages. For example, various embodiments of the present invention beneficially provide a means to identify lithology type and physical properties, truly in real-time. This advantage makes various embodiments of the present invention ideal in the applications of (1) horizontal and lateral well drill steering and (2) locating the relative position for setting the casing shoe at a much higher precision. Various embodiments can also be used to (3) detect fractured zones; and (4) interpret rock lithologies and petrophysical properties. Various embodiments of the present invention beneficially supply more information for evaluating petrophysical properties of the rocks, such as porosity, strength, and presence of hydrocarbons, through the utilization of data obtained through the analysis of acoustic signals to evaluate these petrophysical properties. Such data can beneficially be beyond that which can be conventionally supplied.
[0072] In the drawings and specification, there have been disclosed a typical preferred embodiment of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in considerable detail with specific reference to these illustrated embodiments. It will be apparent, however, that various modifications and changes can be made within the spirit and scope of the invention as described in the foregoing specification.
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Methods of identifying rock properties in real-time during drilling, are provided. An example of such a method includes connecting a downhole sensor subassembly between a drill bit and a drill string, operably coupling acoustic sensors to a downhole data interface, and operably coupling a surface computer to the downhole data interface. The method can also include receiving raw acoustic sensor data generated real-time as a result of rotational contact of the drill bit with rock during drilling, transforming the raw data into the frequency domain, filtering the transformed data, and deriving a plurality of acoustic characteristics from the filtered data. This can be performed by a petrophysical properties analyzing program stored in memory of the computer. The method can also include deriving petrophysical properties from the filtered data utilizing a petrophysical properties evaluation algorithm employable to predict one or more petrophysical properties of rock undergoing drilling.
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FIELD OF THE INVENTION
[0001] The present invention is directed to a system using an intermittent plunger lift and a subsurface safety valve.
BACKGROUND
[0002] As gas wells age, reservoirs deplete and gas velocities become insufficient to lift the fluids associated with production from the subterranean reservoir. The completion equipment alone can provide significant challenges in maintaining unloaded production since completion components can act as mechanical restrictions to the production enhancement equipment designed to optimize production.
[0003] Completion of a conventional plunger lift well consists of a no-go seal landing assembly equipped with a standing valve and a bumper spring disposed in the tubing string at a predetermined depth coinciding with the uppermost selective profile nipple. The surface equipment consists of a receiver or lubricator on surface to receive the plunger above the wellhead. The receiver is furnished with a manual or pneumatically actuated catcher to catch and hold the plunger at surface. The plunger lift system cycle is controlled using an electronic wellhead controller. The wellhead controller controls the signal to the motor valve which opens and closes the well to production as required and activates and releases the catcher to catch and release the plunger at surface in a timed sequence as programmed in the controller.
[0004] One completion component of note is the subsurface safety valve (SSSV). These valves are typically landed about 50 m to 300 m below the surface of the producing well. In many applications, these SSSVs are required to remain in an active state to provide well control in the event of an emergency, therefore, they cannot be disabled during the production operation. Some provisions exist including re-zoning of a producing well whereby the SSSV may be deactivated and production of the well can continue. In this case the SSSV remains intact but functionally disabled in the wellbore for the remainder of the well's producing life. Therefore the challenge becomes lifting the produced liquids to surface utilizing the existing wellbore configuration and thereby avoiding costly workover expenditures.
[0005] Other alternative workovers including capillary strings specially designed to pass around a specialty SSSV. These completions will also require workovers to pull and replace the SSSV with the special model for capillary string installation.
[0006] Therefore, in conventional completions, bumper spring assemblies are landed in the bottom of the well below the SSSV, and the plunger is cycled below the valve. In this method the plunger cycles without any control below the SSSV and therefore arrivals cannot be identified and cannot be optimized. This type of system results in uncontrolled cycling of the plunger between the bottom hole spring immediately below the SSSV and the lower most spring assembly landed at or near the end of the tubing string. Uncontrolled cycling of the tubing plunger can result in significant damage to many components of the plunger lift system.
[0007] As is well known in the art, a plunger allowed to free cycle in any tubing string in an uncontrolled fashion will lead to significant equipment damage due to uncontrolled free fall and rapid ascent of the plunger. The most detrimental component of this operation is the inability to control plunger cycles to ensure that a sufficient liquid slug travels above the plunger to cushion the arrival at the wellhead lubricator. Equally important is allowing a sufficient flow time between cycles to build a fluid column in the tubing string above the bottom-hole assembly. This fluid head serves to cushion the landing of the plunger on the bottom-hole assembly.
[0008] Flowing the well to its best potential requires that no significant back pressure should be present during the operation. The addition of a safety valve in the production tubing string acts as an obstacle to the efficient and consistent cycling of the plunger.
[0009] Therefore, there is a need in the art for a system which more efficiently utilizes a plunger lift system and a subsurface safety valve.
SUMMARY OF THE INVENTION
[0010] The invention relates to a plunger lift system for lifting produced fluids from a bottom hole spring assembly, wherein the plunger cycles through a modified safety valve to a wellhead receiver (lubricator) on surface.
[0011] In one aspect, the invention comprises a plunger lift production system comprising:
[0012] (a) a production string comprising a bottom hole assembly, a production tubing having an inside diameter and including a safety valve having an inside diameter;
[0013] (b) a plunger comprising a plunger body having an outside diameter which closely matches the inside diameter of the safety valve, and an expandable lug and pad assembly, which when expanded closely matches the inside diameter of the production tubing, and when not expanded closely matches the inside diameter of the safety valve.
[0014] In another aspect, the invention comprises a method of producing fluids from a subterranean wellbore having a production string comprising a bottom hole assembly, a production tubing having an inside diameter and including a safety valve having an inside diameter, the method comprising the step of cycling a plunger within the production string through the safety valve, wherein the plunger comprises a plunger body having an outside diameter which closely matches the inside diameter of the safety valve, and an expandable lug and pad assembly, which when expanded closely matches the inside diameter of the production tubing, and when not expanded closely matches the inside diameter of the safety valve.
[0015] Accordingly, the plunger is able to effectively sweep the produced liquids from the well bottom to top, through a safety valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the drawings, like elements are assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles of the present invention. Additionally, each of the embodiments depicted are but one of a number of possible arrangements utilizing the fundamental concepts of the present invention. The drawings are briefly described as follows:
[0017] FIG. 1 shows a schematic of one embodiment of a production system.
[0018] FIG. 2A shows a partial cutaway of one embodiment of a plunger for use in a production system. FIG. 2B shows another embodiment of a plunger with a lug and pad assembly retracted. FIG. 2C shows an end view of the view of FIG. 2B . FIG. 2D shows the embodiment of 2 B with the lug and pad assembly expanded. FIG. 2E shows an end view of the view of FIG. 2D . FIG. 2F shows a cross-sectional view along line 2 F in FIG. 2B .
[0019] FIG. 3 shows partial cutaways of one embodiment of a subsurface safety valve in both open and closed configurations.
[0020] FIG. 4 shows a partial cutaway of another embodiment of a subsurface safety valve.
[0021] FIG. 5 shows a pressure trend graph in a prior art production system.
[0022] FIG. 6 shows a pressure trend graph with implementation of a production system and method of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] The invention relates to a system and method of using a plunger lift with a subsurface safety valve. When describing the present invention, all terms not defined herein have their common art-recognized meanings. To the extent that the following description is of a specific embodiment or a particular use of the invention, it is intended to be illustrative only, and not limiting of the claimed invention. The following description is intended to cover all alternatives, modifications and equivalents that are included in the spirit and scope of the invention, as defined in the appended claims.
[0024] Bottom hole completions for producing wells using intermittent plungers are well known. Examples of such completion systems are described in U.S. Pat. No. 7,347,273 issued on Mar. 25, 2008, the contents of which are incorporated by reference (where permitted). These bottom hole completions are facilitated by providing a bottom hole assembly which can be deployed by slickline through a safety valve, and landed at or near the bottom of the tubing string.
[0025] To efficiently optimize a producing well using a plunger lift system the cycles must be controlled. Monitoring the plunger cycle for optimizing production requires analysis of the signature plunger arrival which can only be accomplished with recorded arrivals. The apparatus and system for monitoring and controlling the plunger cycle are well known in the industry and need not be further described herein.
[0026] A wellbore schematic is shown in FIG. 1 . As a result of the completion, a bottom hole sliplock and spring assembly ( 10 ) is landed in the production tubular ( 12 ) in the wellbore. A thru-sleeve plunger ( 14 ) impacts the spring assembly at the end of its descent in the wellbore, resulting in the plunger being prepared to ascend in the production tubular under fluid pressure, carrying production fluids with it up to the surface.
[0027] Completions of the well in this fashion to maintain unloaded production is highly economic since the producers can avoid costly workovers involving pulling the tubing and removing a safety valve in favor of installing a wireline retrievable model.
[0028] The safety valve ( 30 ), one embodiment of which is shown in FIG. 3 , is designed to be placed in the production tubing, to provide flow control in planned or unplanned shutdowns. The flapper valve ( 32 ) opens and closes a throughbore ( 34 ) which is sized to permit the plunger ( 14 ) to pass through. In one embodiment, the safety valve is tubing retrievable, as contrasted with wireline retrievable configurations. One embodiment of a tubing retrievable safety valve or TRSSSV ( 30 ) is shown in FIG. 4 .
[0029] In contrast to a conventional method of completing a plunger lift well, a TRSSSV well equipped with a plunger lift will consist of a hold down selective in nature since the first restriction which it must pass through is the selective profile nipple within the TRSSSV. The selective nature of the landing assembly allows securing of the bottom-hole assembly and bumper spring at any desired depth below any number of existing selective profile nipples. This can be accomplished using a device such as that described in U.S. Pat. No. 7,347,273, the contents of which are incorporated herein by reference where permitted, or the like.
[0030] As shown in FIGS. 2A-2F , the plunger ( 14 ) is equipped with specialized pad mandrels ( 16 ) with spring loaded lugs ( 20 ) design to allow the lugs ( 20 ) and pads ( 18 ) to collapse to the outside diameter (OD) of the plunger body and thereby guarantee passage of the plunger through the safety valve ( 30 ). Upon expansion of the lugs ( 20 ) and pads ( 18 ) with assistance of the spring ( 17 ), the plunger meets the production tubing ID, while collapsing to pass through the safety valve ( 30 ) and not substantially affecting performance of the plunger.
[0031] As shown in FIG. 2F , the pads ( 18 ) and lugs ( 20 ) are interlocking such that movement of the lugs causes movement of the pads. In one embodiment, the lugs ( 20 ) are equipped with small pins ( 24 ) which travel within radial grooves in the pad mandrel to guide radial travel of the lug and prevent binding of the lug on the pad mandrel.
[0032] The top sub of the plunger may incorporate a valve mechanism, such as that described in U.S. patent application Ser. No. 12/027,062 filed Feb. 6, 2008, the contents of which are incorporated herein by reference, where permitted. Therefore, when the plunger is falling through the wellbore, the top valve of the plunger remains open, allowing any gas or liquid in the wellbore to pass through the plunger. The valve closes when the plunger lands on the bottom hole assembly, and production pressure causes the plunger to rise up, pushing production fluids above it to the surface. The spring ( 17 ) pressure pushes the lugs and pads radially outwards, to contact the production tubing surface.
[0033] In one embodiment, the plunger body comprises chamfered edges ( 22 ) at both top and bottom ends, which facilitates entry and passage of the plunger through the safety valve. The pads themselves are chamfered or rounded such that when the plunger enters the reduced diameter bore of the safety valve, the pads are physically retracted into the plunger, as is shown in FIGS. 2B and 2C . Upon exiting the safety valve, the spring ( 17 ) assists in expanding the pads once again, as is shown in FIGS. 2D and 2E . The plunger preferably has enough mass to allow easy passage downwards through the safety valve.
[0034] In this system and method, efficient use of the existing completion/tubing strings in a given wellbore may be made. The plunger ( 14 ) cycles through the tubing retrieved sub- surface safety valve ( 30 ). In this case, the safety valve ( 30 ) valve remains intact and operational whilst the fluid is produced to surface cycling the plunger ( 14 ) through the safety valve.
[0035] Due to the low reservoir pressures in a typical plunger lift application, small accumulations of fluid in the tubing string can dramatically decrease the inflow from the reservoir. This can be visualized by the discrepancy between the sale pressure and the casing pressure in FIG. 4 . As shown with the production trend in FIG. 5 , with the plunger in place and cycles controlled, the sales and casing pressure trendlines are tracking very closely indicating the flowing differential due to the accumulated liquid head in the tubing has been eliminated. This type of information and degree of control over the plunger lift system can be achieved by tracking and recording the plunger arrivals and catching and holding the plunger at surface using a programmed sequence in the wellhead controller. The present invention permits such programmed sequences with an active safety valve in place.
[0036] As will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the scope of the invention claimed herein.
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A plunger lift production system uses a production string including a bottom hole assembly, a production tubing having an inside diameter and including a safety valve having an inside diameter, and a plunger with an outside diameter which closely matches the inside diameter of the safety valve, and an expandable lug and pad assembly, which when expanded closely matches the inside diameter of the production tubing, and when not expanded closely matches the inside diameter of the safety valve.
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This application is based on Patent Application No. 2000-369105 filed Dec. 4, 2000 in Japan, the content of which is incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet printing apparatus, and more particularly to an ink jet printing apparatus and an ink jet printing method which eject ink by an energy generated by an electrothermal transducer.
2. Description of the Related Art
Generally, the ink jet printing apparatus performs printing by relatively moving an ink jet print head over a print medium while ejecting ink from the head. In the ink jet printing apparatus, a quality of the printed result depends on such factors as a control of a relative speed between the print head and the print medium, a control of an ejection timing associated with the relative speed control, and a stability of power supply to the print head. The ink jet printing apparatus is classed into a serial type and a full-line type according to the type of the print head used. The serial type is a widely used printing apparatus in which the print head is reciprocally moved in a direction crossing a print medium feeding direction while ejecting ink from the head.
There are several types of print head, including one which ejects ink by activating a piezoelectric element and a so-called bubble jet type which generates a bubble by an instant surface boiling and ejects ink by using a pressure of the bubble as an ejection energy. The print head of the bubble jet type causes the surface boiling of ink by energizing a heater installed near an ink ejection nozzle in an ink path.
In such ink jet printing apparatus, it is important in keeping the print quality satisfactory that the energy for ejecting ink be supplied stably at all times to eject the ink under the same condition and thereby produce uniform ink droplets. However, the number of heaters that are energized simultaneously is not fixed but changes according to a duty ratio of image data. Hence, the heater driving condition varies, affected by voltage variations due to changes in an output current of the power supply and by variations in voltage drop due to resistance component changes in a power supply system.
Hence, in conventional ink jet printing apparatus, it is common practice to enhance the precision of power supply output and construct the power supply system with as little loss as possible so that the printing apparatus can be operated in a range that can meet the ejection requirements.
As color image handling is made easy by increased speeds of personal computers in recent years, the amount of data to be processed and the processing speed are increasing rapidly.
Although the speed of the ink jet printing operation can be enhanced by increasing the ink ejection frequency and the number of nozzles that can be energized simultaneously, this gives rise to a problem that a change in the number of nozzles that are energized simultaneously in the actual printing operation becomes large. That is, of the nozzles that can be energized at one time, the number of nozzles used in the actual printing operation changes according to the image data being printed. When the number of nozzles that can be energized simultaneously is increased to enhance the printing speed as described above, the number of nozzles energized simultaneously varies greatly depending on the image data.
For example, when printing a black solid image, all the nozzles that can be energized for simultaneous ink ejection are used. When printing a low-duty image, such as lines, only a part of the available nozzles are used for simultaneous ink ejection. In this way, the number of nozzles that are driven simultaneously varies depending on the image data. This variation becomes more conspicuous as the total number of nozzles in the print head increases. The difference (or change) in the number of nozzles that need to be driven simultaneously results in a difference (or change) in the current that needs to be supplied to the ejection energy generating means such as heaters.
A circuit for supplying electricity to the ink jet print head for ink ejection has a resistance component, such as contact resistance with a connector and its own wiring resistance. Hence, when the heaters are in a conducting state, the voltage applied to the print head drops in proportion to the current because of the heater resistance component. If the current changes greatly as a result of a change in the number of simultaneously energized nozzles, the drive voltage applied to the heaters of the print head also changes, posing a problem that the ink ejection cannot be performed under the same condition. That is, as the change in the drive voltage increases, the resulting variations in the ink ejection condition greatly influence the print quality, which is detrimental to improving the speed of the printing operation. Therefore, if an ink ejection control which can keep the ejection condition from changing according to the print data is possible, the speed of the printing operation can be increased.
To realize such an ink ejection control, image recording apparatus have been proposed and practiced, which include one comprising a count means for counting print data to monitor the number of nozzles that are actually energized for ink ejection and an output voltage changing means for changing the output voltage of a power supply according to the count value, and one comprising the count means, a variable resistance load means for changing a resistance in a power supply circuit to the print head, and a control means for setting a value of the variable resistance according to the count value.
In these printing apparatus, a control is made in such a way that when the number of simultaneously energized nozzles is large, the resistance value of the variable resistance load means is reduced and that when the number of simultaneously energized nozzles is small, the resistance value is increased. This arrangement can control the voltage drop caused when the current flowing through the heaters passes through this variable resistance load means, thereby keeping the voltage applied to the heaters during ink ejection constant and the ejection condition uniform.
The image forming apparatus described above that counts the number of simultaneously energized nozzles, however, has the following problem. That is, although the count value can be monitored easily since it is a digital quantity, the variable resistance load means easily experience characteristic variations and degradation of characteristics over time, so that simply performing the control based on the energized nozzle count value cannot achieve an accurate control nor a satisfactory print quality.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an ink jet printing apparatus and method with an inexpensive arrangement that allows a stable supply of an appropriate voltage to heaters without requiring a variable resistance load means or a power supply voltage changing means.
According to one aspect the present invention provides an ink jet printing apparatus which comprises: a plurality of nozzles arrayed in a print head; a plurality of energy generating means for generating an ejection energy to eject ink from the nozzles, the plurality of energy generating means being divided into a plurality of blocks; and a drive control means for supplying an energy through an energy supply path to the energy generating means in each block simultaneously; wherein the drive control means supplies an energy to at least a part of the energy generating means making up each block through a plurality of different kinds of the energy supply paths.
That is, the Ink jet printing apparatus of this invention has a plurality of nozzles arrayed in a print head; and a plurality of energy generating means for generating an ejection energy to eject ink from the nozzles; wherein the energy generating means have a plurality of energy supply paths and a drive control means for simultaneously driving a part of the plurality of the energy generating means. This apparatus is characterized in that the plurality of the energy generating means connected, in one-to-one relationship, to n different supply paths constitute one block and that the drive control means is so arranged as to simultaneously drive as the same block the energy generating means each forming an element of each one of different groups.
According to another aspect, the present invention provides an ink jet printing apparatus which comprises: a plurality of nozzles arrayed in a print head; and a plurality of energy generating means for generating an ejection energy to eject ink from the nozzles; wherein the print head having the energy generating means has a wiring pattern formed on a heater board therein in such a way that wiring resistances of energy supply paths running to different nozzles are equal.
According to still another aspect, the present invention provides an ink jet printing apparatus which comprises: a plurality of nozzles arrayed in a print head; and a plurality of energy generating means for generating an ejection energy to eject ink from the nozzles; wherein the print head having the energy generating means is mounted on each of a plurality of carriages that move on different moving paths, and a long power supply path connecting to the print heads mounted on one of the carriages is formed with a wire material of a lower electric resistance than that of a wire material of a short power supply path connecting to the print heads mounted on another carriage.
According to a further aspect, the present invention provides a printing method which comprises the steps of: dividing a plurality of energy generating means into a plurality of blocks, the energy generating means being adapted to generate an ejection energy to eject ink from nozzles; and simultaneously energizing the energy generating means in each block to perform printing; wherein a control is performed to supply an energy to at least a part of the energy generating means making up each of the blocks through a plurality of different kinds of energy supply paths.
As described above, with this invention, since a stable supply of electricity can be made through a plurality of head drive power supply paths, without being affected by a change in the number of nozzles that are simultaneously energized, the ink ejection condition remains stable assuring the printing of high-quality images.
Further, even when the head drive power supply paths differ in length, their wiring resistances can be made equal, keeping the ejection conditions uniform among different nozzles and thus assuring the printing of high-quality images.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a characteristic configuration of a first embodiment of the present invention;
FIG. 2 is a block diagram schematically showing an overall configuration of an ink jet printing apparatus;
FIG. 3 is a perspective view showing a construction of a mechanism portion of the ink jet printing apparatus;
FIG. 4 is a timing chart showing output timings of heat signals in first to fourth heat blocks;
FIG. 5 is a schematic plan view of a second embodiment of the present invention; and
FIG. 6 is a block diagram showing power supply paths from a power unit to the print head.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Now, embodiments of the present invention will be described by referring to the accompanying drawings.
(First Embodiment)
A first embodiment of this invention will be explained.
As shown in FIG. 3, in the ink jet printing apparatus of this embodiment, a carriage 3 is slidably attached along the guide shafts 6 A, 6 B arranged parallel to a direction of scan. This carriage 3 mounts on it four ink jet print heads 211 (black (BK) head 213 , yellow (Y) head 214 , magenta (M) head 215 and cyan (C) head 216 ) for associated ink colors and four ink tanks integrally attached to the associated print heads. A home position sensor (HP sensor) 8 is installed at one end of the apparatus to optically detect when the carriage 3 is at a home position.
The carriage 3 is connected to a part of a drive belt 4 that transmits a driving force of a carriage drive motor 5 to the carriage so that it is reciprocally moved along the guide shafts 6 A, 6 B by the driving force of the carriage drive motor 5 .
A sheet of print paper (print medium) is fed from a medium supply unit not shown onto a platen 7 arranged opposite ejection surfaces of the print heads 211 . The print paper feeding operation is performed intermittently and repetitively after each reciprocal motion of the carriage 3 to allow the print heads to eject ink during the forward or backward movement according to image data to form an image on the print paper.
The ink jet print heads 213 - 216 have a number of narrow pipe-shaped ink ejection nozzles arranged in the ejection surfaces facing a print surface of the print paper Heaters as ejection energy generating means for generating energy to eject ink are provided one in each of the nozzles near the nozzle outlets. The nozzle outlets of the print heads 213 - 216 are arrayed in a direction perpendicular to the scan direction of the carriage 3 . The four print heads 213 - 216 are arranged side by side in the carriage scan direction.
The HP sensor 8 detects a reference position detection projection 12 when the carriage 3 slides along the guide shaft 6 A, 6 B in the initial stage of operation. The result of detection is used to determine the carriage home position HP, which represents a reference position in the scan direction for the printing operation.
In the ink jet printing apparatus, the print control unit not shown which will be described later receives the image information and control command data entered from an external host device and unfolds the image data into data of each color component. Then, the print control unit transfers the unfolded image data to the print heads and at the same time performs a series of printing operations of scanning the carriage 3 and ejecting ink at required timings.
The print control unit and the carriage 3 are connected to each other by a flexible cable 13 as power supply paths.
Next, the print control unit in the ink jet printing apparatus of this embodiment will be explained by referring to FIG. 2 .
The print control unit 203 shown in FIG. 2 comprises a CPU 204 , ROM 205 and RAM 206 as memory units, an interface circuit 207 interfacing with an external host device 201 , a motor control circuit 210 for driving the paper feed motor 10 and the carriage drive motor 5 , and a gate array (G.A.) 208 as a logic circuit for performing a variety of controls to support the operation of the CPU 204 . A head control unit 209 for controlling the ink ejection timing and executing the ink ejection from the print heads 211 is formed in the gate array 208 .
The carriage drive motor 5 uses a stepping motor. The CPU 204 issues a drive signal for the carriage drive motor 5 to the motor control circuit 210 to move the carriage 3 , and at the same time counts the number of drive signals from the main scan direction reference position to determine the current position of the carriage 3 in the main scan direction. When the carriage 3 reaches the position where the print heads 213 - 216 are to eject ink, the head control unit 209 energizes the heaters to eject ink.
Although in this embodiment the current printing position in the main scan direction is detected by counting the drive pulses of the motor, there is a known printing apparatus which determines the printing position by using a linear encoder having a scale arranged in the main scan direction.
The CPU 204 also performs an overall control on the operation of the ink jet printing apparatus according to a program preinstalled in the ROM 205 or a control command entered from the host device 201 through the interface circuit 207 . The ROM 205 stores programs to be run by the CPU 204 , various table data necessary for head control, and character data for generating character-based information.
The interface circuit 207 allows for the transfer of control commands from the host device 201 to the ink jet printing apparatus and the input/output of control data between them. The RAM 206 includes a work area used by the CPU 204 for calculation and a temporary storage area for the print data and control code entered from the host device 201 through the interface circuit 207 . It also includes a print buffer in which the print data, after having been developed into bit data corresponding to the nozzles of the print heads, is stored.
Next, the ejection drive circuit and the ejection control of the print heads 211 will be described in more detail.
In this embodiment four heads mounted on the carriage 3 are used as described above. Because the operation principles for all print heads are the same, the print head (BK) 214 for ejecting a black ink Is taken for example.
In this embodiment, each print head is formed with a plurality of nozzles, each of which has a nozzle heater (energy generating means) 117 arranged therein. These nozzle heaters 117 are divided into a plurality of heat blocks (n-blocks in this case) according to the drive timing. Each heat block has 4 nozzle heaters that are to be energized simultaneously.
That is, in FIG. 1 a first heat block consists of nozzle heaters 1 - 1 , 1 - 2 , 1 - 3 , 1 - 4 a second heat block consists of nozzle heaters 2 - 1 , 2 - 2 , 2 - 3 , 2 - 4 , a third heat block consists of nozzle heaters 3 - 1 , 3 - 2 , 3 - 3 , 3 - 4 , and a fourth heat block consists of nozzle heaters 4 - 1 , 4 - 2 , 4 - 3 , 4 - 4 , . . . and, n- 1 , n- 2 , n- 3 , n- 4 .
The nozzles on the print head are arranged in line and the nozzle heaters on the print head are also arranged in line. The nozzle heaters in the same heat block are arranged in the order of ascending nozzle number at every n position in the line of nozzle heaters. For example, the first nozzle in the first heat block 1 - 1 is followed by the first nozzle in the second heat block 2 - 1 , which is followed by the first nozzle in the third heat block 3 - 1 , which is followed by the first nozzle in the fourth heat block 4 - 1 . . . and which is followed by the first nozzle in the n-th heat block n- 1 . This is further followed by the second nozzle in the first heat block 1 - 2 and so on.
Of the arrangement number attached to each nozzle heater, a number preceding the hyphenation (-) denotes a heat block number whose nozzle heaters are energized simultaneously and a number following the hyphenation (-) denotes a group number whose nozzle heaters have the same power supply. Thus each nozzle heater can be identified by the block number and the group number.
One end of each nozzle heater is connected to the power unit (energy source) 300 through a drive transistor 118 and a power supply path Vh 119 . The power unit 300 comprises a plurality of sub-power supplies that correspond in one-to-one relationship to the power supply paths to protect each of the power supply paths Vh 119 - 1 , 2 , 3 , 4 against possible electric fluctuations. This arrangement ensures stably supply of electricity to each power supply path.
The power supply path Vh 119 has n wires (wire 119 - 1 , 119 - 2 , 119 - 3 , 119 - 4 ). The wire 119 - 1 is connected through the drive transistor 118 to the nozzles of first group 121 , the wire 119 - 2 to the nozzles of second group 122 , the wire 119 - 3 to the nozzles of third group 123 , and the wire 119 - 4 to the nozzles of fourth group 124 .
Also, the stabilization circuit corresponding to each power supply path can be prepared instead of the sub power supply to compensate electric change.
The opposite end of each nozzle heater 117 is connected to a power supply path Vh 220 of the power unit 300 . The power supply path Vh 220 has four wires (wire L 21 -L 24 ) each connected to the associated nozzle group of nozzle heaters. That is, the wire L 21 Is connected to nozzle heaters 1 - 1 , 2 - 1 , . . . , n- 1 belonging to the first group 121 , the wire L 22 to nozzle heaters 1 - 2 , 2 - 2 , . . . , n- 2 belonging to the second group 122 , the wire L 23 to nozzle heaters 1 - 3 , 2 - 3 , . . . , n- 3 belonging to the third group 123 , and the wire L 24 to nozzle heaters 1 - 4 , 2 - 4 , . . . , n- 4 belonging to the fourth group 124 .
The energizing of each nozzle heater 117 , i.e., the supply of current, is done by switching the drive transistor 118 . The drive transistor 118 is turned on or off by a head controller 209 and a nozzle selector 220
The head controller 209 outputs an image data signal 108 , a clock signal 110 and a latch signal 109 through a data circuit of each color (Bk data circuit 104 , Y data circuit 105 , M data circuit 106 and C data circuit 107 ) to the nozzle selector 220 for each color print head in order to issue ejection data to the corresponding color print heads.
The nozzle selector 220 comprises a shift register 111 , a latch circuit 112 and an AND circuit 116 . The shift register 111 and the latch circuit 112 each have bits corresponding in one-to-one relationship to the nozzle heaters 117 , with adjoining n bits forming each group 121 , 122 , . . . These groups 121 , 122 , . . . correspond to the first groups second group, . . . of nozzle heaters respectively. The shift register 111 receives image data 108 and a clock signal 110 from a data transfer circuit 102 through the Bk data circuit 104 . The latch circuit 112 is supplied a latch signal 109 .
The AND circuit 116 has three input terminals and is interposed between each bit of the latch circuit and the drive transistor 118 . The AND circuit 116 has its output terminal connected to a base of the associated transistor 118 and one of its input terminals connected with an output of the latch circuit 112 . The AND circuit 116 has another input terminal supplied with an output signal from a block decoder 115 and a third input terminal supplied with a heat signal 114 .
The head controller 209 , the nozzle selector 220 , and power supply paths Vh 119 , Vh 220 together form a drive control unit.
In the ink jet printing apparatus of the above construction, as shown in FIG. 2, the image data entered from the host device 201 through the interface circuit 207 is, as described earlier, stored temporarily in the RAM 206 and then read by the head controller 209 and supplied to the data transfer circuit 102 and a heat timing controller 103 . The data transfer circuit 102 outputs the data signal 108 , latch signal 109 and clock signal 110 . The data signal 108 is successively transferred to each bit of the shift register 111 in synchronism with the clock signal. When data for all nozzle heaters is stored in the shift register 111 , the latch signal 109 is input to the latch circuit 112 to complete the data setting.
With the data setting completed, the heat timing controller 103 outputs a pair of block selection signals 113 and a heat signal 114 according to the position of the carriage 3 . Based on the pair of block selection signals 113 , the block decoder 115 outputs a signal that activates a predetermined input of the AND circuit 116 corresponding to the block that needs to be driven.
When the heat signal 114 is input to the nozzles for which the data setting and block selection were made according to the procedure described above, the AND circuit 116 produces its output to turn on the drive transistor 118 connected to the nozzle heater 117 of each nozzle, supplying the drive current to the nozzle heaters. The heat signal 114 is used to control the actual heating duration for temperature control.
By successively repeating the sequence of operations described above, ink droplets can be ejected onto desired positions on the print medium during a series of printing operations.
The plurality of the nozzle heaters in the print head 214 are not driven all at one time but are time-divided for operation at staggered times in order to spread the supply of the energy required for ink ejection. This time division driving of the nozzle heaters is done by differentiating the output timings of the heat signal 114 . For the time-division driving, the nozzle heaters of the print head 214 are divided according to the blocks mentioned above. For example, when the head ejection frequency is 10 kHz, the first to fourth block are energized at different timings as shown in FIG. 4 .
Four nozzle heaters in each block can be energized simultaneously by the data entered. For example, when the block decoder outputs a selection signal corresponding to a specified block, two input terminals of each AND circuit 116 belonging to that block are made active by the selection signal and the heat signal. Hence, if the bits in the latch circuit 112 that correspond to the selected block are all set with data, all three input terminals of each of all the AND circuits 116 corresponding to these bits become active, producing outputs. As a result, all the nozzles heaters of one block are simultaneously energized through the drive transistors 118 .
Therefore, even when the number of nozzles that need to be driven simultaneously changes due to presence or absence of data or variation in the duty ratio, the magnitude of change is reduced to one fourth because the change is divided among the four blocks sub-power supplies. This can prevent the power supply voltage of the power unit from changing significantly, making it possible to maintain a constant ejection condition at all times and therefore form an image with high quality.
FIG. 6 shows the connection between one of the print heads and the power supply paths Vh 119 - 1 , 119 - 2 , 119 - 3 , 119 - 4 for the four groups that are supplied by the power unit 300 , and also shows how the power supply paths are wired on the heater board in the print head 214 . When the power supply paths bundled and wired up to the print head 214 are separately wired to individual nozzle heaters, a wire pattern on the heater board is formed as follows. The wire to a nozzle nearest the power supply side is formed smallest in width and the wire to a nozzle farthest from the power supply side is formed largest in width in order to ensure that the resistances of the wires running from the end face of the print head to the different nozzles are equal. This arrangement realizes a stable supply of electricity to all nozzle heaters regardless of their distances from the end face of the print head.
Although the above embodiment has described a case where four power supply paths corresponding to four groups are independently provided as the energy generating means, the number of power supply path groups may be increased or decreased as required. It is also possible to provide the same number of power supply paths as the total number of nozzle heaters. The present invention is not limited to the above embodiment.
Further, the number of nozzles that are driven simultaneously is not limited to that of this embodiment and may be determined as required. While this embodiment has been described to use a serial type ink jet printing apparatus, this invention is not limited to this type but may be applied to a printing apparatus with a full-line type print head.
(Second Embodiment)
A second embodiment of this invention will be described.
While in the first embodiment n blocks of simultaneously driven nozzle heaters are each provided with an independent energy supply path, the second embodiment is characterized by an arrangement which, when the lengths of these independent power supply paths differ from each other, keeps impedances of these paths equal.
FIG. 5 shows a schematic construction of the ink jet printing apparatus according to the second embodiment. The ink jet printing apparatus 506 has two carriages 503 and 505 . These carriages perform printing operations by reciprocally scanning over different ranges that are defined by dividing the print medium 507 in half in the main scan direction. Hence, the power supply paths 502 and 504 have different lengths from each carriage to the power supply unit 501 and therefore different wiring resistances. This difference in wiring resistance is eliminated by increasing the width of the long power supply paths 504 to reduce their electric resistances down to those of the shorter power supply paths 502 . The similar effect of making these wiring resistances equal may also be obtained by increasing the thickness of the wires of the long power supply paths 504 .
By differentiating the wiring resistances it is possible to keep the ejection conditions uniform among different nozzles and realize a high-quality printing even when the energy supply path lengths differ from each other.
(Others)
The present invention achieves distinct effect when applied to a recording head or a recording apparatus which has means for generating thermal energy such as electrothermal transducers or laser light, and which causes changes in ink by the thermal energy so as to eject ink. This is because such a system can achieve a high density and high resolution recording.
A typical structure and operational principle thereof is disclosed in U.S. Pat. Nos. 4,723,129 and 4,740,796, and it is preferable to use this basic principle to implement such a system. Although this system can be applied either to on-demand type or continuous type ink jet recording systems, it is particularly suitable for the on-demand type apparatus. This is because the on-demand type apparatus has electrothermal transducers, each disposed on a sheet or liquid passage that retains liquid (ink), and operates as follows: first,. one or more drive signals are applied to the electrothermal transducers to cause thermal energy corresponding to recording information; second, the thermal energy induces sudden temperature rise that exceeds the nucleate boiling so as to cause the film boiling on heating portions of the recording head; and thirds bubbles are grown in the liquid (ink) corresponding to the drive signals. By using the growth and collapse of the bubbles, the ink is expelled from at least one of the ink ejection orifices of the head to form one or more ink drops. The drive signal in the form of a pulse is preferable because the growth and collapse of the bubbles can be achieved instantaneously and suitably by this form of drive signal. As a drive signal in the form of a pulse, those described in U.S. Pat. Nos. 4,463,359 and 4,345,262 are preferable. In addition, it is preferable that the rate of temperature rise of the heating portions described in U.S. Pat. No. 4,313,124 be adopted to achieve better recording.
U.S. Pat. Nos. 4,558,333 and 4,459,600 disclose the following structure of a recording head, which is incorporated to the present invention: this structure includes heating portions disposed on bent portions in addition to a combination of the ejection orifices, liquid passages and the electrothermal transducers disclosed in the above patents. Moreover, the present invention can be applied to structures disclosed In Japanese Patent Application Laying-open Nos. 59-123670 (1984) and 59-138461 (1984) in order to achieve similar effects. The former discloses a structure in which a slit common to all the electrothermal transducers is used as ejection orifices of the electrothermal transducers, and the latter discloses a structure in which openings for absorbing pressure waves caused by thermal energy are formed corresponding to the ejection orifices. Thus, irrespective of the type of the recording head, the present invention can achieve recording positively and effectively.
The present invention can be also applied to a so-called full-line type recording head whose length equals the maximum length across a recording medium. Such a recording head may consists of a plurality of recording heads combined together, or one integrally arranged recording head.
In addition, the present invention can be applied to various serial type recording heads: a recording head fixed to the main assembly of a recording apparatus; a conveniently replaceable chip type recording head which, when loaded on the main assembly of a recording apparatus, is electrically connected to the main assembly, and is supplied with ink therefrom; and a cartridge type recording head integrally including an ink reservoir.
It is further preferable to add a recovery system, or a preliminary auxiliary system for a recording head as a constituent of the recording apparatus because they serve to make the effect of the present invention more reliable. Examples of the recovery system are a capping means and a cleaning means for the recording head, and a pressure or suction means for the recording head. Examples of the preliminary auxiliary system are a preliminary heating means utilizing electrothermal transducers or a combination of other heater elements and the electrothermal transducers, and a means for carrying out preliminary ejection of ink independently of the ejection for recording. These systems are effective for reliable recording.
The number and type of recording heads to be mounted on a recording apparatus can be also changed. For example, only one recording head corresponding to a single color ink, or a plurality of recording heads corresponding to a plurality of inks different in color or concentration can be used. In other words, the present invention can be effectively applied to an apparatus having at least one of the monochromatic, multi-color and full-color modes. Here, the monochromatic mode performs recording by using only one major color such as black. The multi-color mode carries out recording by using different color inks, and the full-color mode performs recording by color mixing.
Furthermore, although the above-described embodiments use liquid ink, inks that are liquid when the recording signal is applied can be used; for example, inks can be employed that solidify at a temperature lower than the room temperature and are softened or liquefied in the room temperature. This is because In the ink jet system, the ink is generally temperature adjusted in a range of 30° C.-70° C. so that the viscosity of the ink is maintained at such a value that the ink can be ejected reliably. In addition, the present invention can be applied to such apparatus where the ink is liquefied just before the ejection by the thermal energy as follows so that the ink Is expelled from the orifices in the liquid state, and then begins to solidify on hitting the recording medium, thereby preventing the ink evaporation, the ink is transformed from solid to liquid state by positively utilizing the thermal energy which would otherwise cause the temperature rise; or the ink, which is dry when left in air, is liquefied in response to the thermal energy of the recording signal. In such cases, the ink may be retained in recesses or through holes formed in a porous sheet as liquid or solid substances so that the ink faces the electrothermal transducers as described In Japanese Patent Application Laying-open Nos. 54-56847 (1979) or 60-71260 (1985). The present invention is most effective when it uses the film boiling phenomenon to expel the ink.
Furthermore, the ink jet recording apparatus of the present invention can be employed not only as an image output terminal of an information processing device such as a computer, but also as an output device of a copying machine including a reader, and as an output device of a facsimile apparatus having a transmission and receiving function.
The present invention has been described in detail with respect to various embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.
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This invention provides an ink jet printing apparatus and method with an inexpensive arrangement that allows a stable supply of an appropriate voltage to heaters without requiring varying load resistance or changing a power supply voltage. The ink jet printing apparatus of this invention has a plurality of nozzles arrayed in a print head; a plurality of energy generators installed one in each of the nozzles for generating an ejection energy to eject ink from the nozzles, the plurality of energy generators being divided into a plurality of blocks; and a drive controller f or simultaneously driving the energy generators in each block. The drive controller supplies an energy to the energy generators making up each block through different kinds of energy supply paths.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to electrochemical mediators and their use in electrochemical-based sensors and enzyme-based biofuel cells. The mediators may be immobilised on an electrode.
[0002] The present invention relates, in general, to polymeric mediators, their production and uses.
[0003] Electrochemical-based sensors and enzyme-based biofuel cells both contain a system where one or more redox mediator(s) and one or more redox enzyme(s) are used in conjunction with one or more electrode(s). The redox mediator is a molecule which can shift between oxidised and reduced states and thereby facilitate electron transfer between the reactive centre of an enzyme and an electrode surface. Direct electron transfer from enzyme to electrode is difficult since the reactive centres in most redox enzymes are well protected and deeply buried underneath the protein shells. Such mediators as ferrocene derivatives, quinones and bipyridinium salts have been widely studied and used. For example, the mediator pyrroloquinoline quinone (PQQ) was used with glucose oxidase as an anodic biocatalyst in a glucose-based biofuel cell (N. Yuhashi et al., Biosensors and Bioelectronics (2005) 20, 2145-2150).
[0004] For a continuous or semi-continuous shuttling of electrons between the electrode and the mediator, it is essential that the electron mediator does not leach from the vicinity of the electrode. In addition, the leaching of harmful mediators would be a hazard to the host such as humans. In order to prevent leaching, chemical compositions of the mediators where these are chemically attached to the electrodes and/or to the catalytic enzymes have been investigated. However, the loading of mediators on the electrodes is low and the conjugated mediator-enzymes suffer from a deleterious decrease in enzyme activity.
[0005] Redox polymers have successfully shown their abilities to overcome the leaching problem with additional advantages:
[0006] 1) Control of the reaction rate by the applied potential or current;
[0007] 2) Close proximity of electrocatalytic sites to the electrode;
[0008] 3) High concentration of active centres despite the low amount of material required.
[0009] Typically, a redox polymer consists of a system where a redox-active transition metal based pendant group is covalently bound to some sort of polymer backbone, which may or may not be electroactive. Certain redox mediators can also be polymerised or cross-linked with/without other monomers. Nonetheless, they suffer from low flexibility, reduced mediation activity, limited mediation capacity and poor process ability.
[0010] Dendrimers, like conventional polymers, are built from smaller repeating subunits, but instead of forming linear chains, the subunits branch out in a well-defined pattern from a central point. Through either divergent or convergent syntheses, dendrimers can be made with high regularity and controlled molecular weight, and can be characterised by their structural perfection. These macromolecules consist of a multi-functional central core (or focal point) covalently linked to layers of repeating units and a number of terminal groups.
[0011] Dendritic mediators (C. M. Casado et al., Coordination Chemistry Reviews (1999) 185-186, 53-79) comprising the dendritic structure and redox mediator moieties have attracted great interest in the fields of sensors and biofuel cells, since they could not only facilitate electron shuttling between the redox enzyme and electrode like other conventional redox polymers, but also provide precise structure and size control, improved physical and chemical properties such as high flexibility, low viscosity, high solubility and miscibility, together with enormous and functional surface and interior areas. Another big advantage is their ability to encapsulate or bind guest molecules such as redox enzymes, leading to stable electron shuttling because of the closer and substantial contact. However, as with other dendrimers, dendritic mediators also have intrinsic disadvantages: time-consuming synthesis, difficult purification, high cost and low yield, particularly for the high molecular weight ones. For the use as engineering materials, they are far too complicated and costly to produce.
[0012] Hyperbranched polymers (HBPs) are a young and rapidly growing area within the field of macromolecules. HBPs and dendrimers belong to the same group of polymers with densely branched structures and a large number of reactive groups. As a result, they have some similar properties such as low viscosity, good solubility, and multi-functionality. They also have the potential ability to encapsulate or bind guest molecules. However, dendrimers are defined as monodisperse macromolecules. That is, a dendrimer material is composed of molecules that are uniform with respect to relative molecular mass and constitution. In contrast, HBPs are polydisperse. Compared to dendrimers, HBPs show some great and distinguishable advantages including simplified synthesis, easy purification, high yield and reasonable cost, which make them much more suitable for industrial manufacture.
[0013] The structural difference between these two types of polymers is that while dendrimers have a well defined structure and have a degree of branching of 100% (all branches are “occupied” with the next branch), Hyperbranched polymers are polydispersed macromolecules having irregular and highly branched structures. Hyperbranched polymers can be synthesised in just one-pot step and the fundamental synthesis approaches differ between the two. Whereas dendrimers require absolute control of all synthesis steps, manufacturing of ordinary hyperbranched polymers is accomplished by a simplified approach.
[0014] Synthetically, dendrimers can be achieved mainly in three ways: i) a central core which is either a single atom or an atomic group having at least two identical functions, ii) branches emanating from the core, constituted of several repeating units having at least one branch junction, iii) many terminal functional groups, generally located in the exterior of the macromolecule.
[0015] Hyperbranched polymers, on the other hand, do not need a central core to grow, they are synthesised using a one step polymerisation of AB x type multifunctional monomers or A 2 +B 3 type comonomers. Furthermore the functional groups are not necessarily located in the exterior of the macromolecule.
[0016] Adding to these structural and synthetic differences they posses the same physical properties as dendrimers such as low-viscosity, good solubility and multifunctionality and both posses “tree”-alike structure. Thus, in some ways, hyperbranched polymers can be considered as the alternative of dendrimers but having much easier synthesis.
[0017] Ordinary crosslinked polymers have a main structural difference towards hyperbranched polymers. Crosslinked polymers are essentially constituted of macromolecules that were formed with bonds that link one polymer chain to another forming, therefore, a “net” structure. These are not branches that grew from the functional groups of the monomers. Crosslinked polymers are polymers chains linked to one another.
SUMMARY OF THE INVENTION
[0018] It is therefore an object of the present invention to disclose the use of polymeric mediators and, in particular, of hyperbranched polymeric mediators, in electrochemical-based sensors and enzyme-based biofuel cells.
[0019] In a first aspect the invention provides an electrode assembly comprising an electrode and a redox mediator associated with the electrode so that in use it facilitates transfer of electrons between the electrode and a further entity, wherein the redox mediator comprises a hyperbranched polymer including a plurality of redox mediator moieties.
[0020] In a second aspect the invention provides a redox mediator which comprises a hyperbranched polymer including a plurality of redox mediator moieties.
[0021] According to embodiments of the present invention, the use of hyperbranched polymeric mediators in electrochemical-based sensors and enzyme-based biofuel cells prevents the leaching of unfixed mediators from the vicinity of electrodes while maintaining or improving the mediation activity. In addition, the materials can be compatible with enzymes.
[0022] According to embodiments of the present invention, the modified electrochemical-based sensors and enzyme-based biofuel cells include an electrode to which at least one hyperbranched polymeric mediator is attached.
[0023] According to embodiments of the present invention, for use in electrochemical-based sensors or enzyme-based biofuel cells, a hyperbranched polymeric mediator is provided which comprises a plurality of at least one kind of redox mediators (e.g. ferrocene-based redox mediators). The redox mediator(s) may be chemically incorporated within the HBP or chemically anchored on the periphery of the HBP, or both.
[0024] According to embodiments of the present invention, for the use in an electrochemical-based sensors and an enzyme-based biofuel cell, a method of preparing a hyperbranched polymeric mediator is provided. The redox mediator(s) may be polymerised with/without additional monomer(s) to form a hyperbranched polymeric mediator. The redox mediator(s) may also be introduced via surface modification after the polymerisation to produce an HBP.
[0025] According to embodiments of the present invention, for the use in an electrochemical-based sensors and an enzyme-based biofuel cell, a hyperbranched polymeric mediator HBP is provided which is prepared according to the above-stated method.
[0026] According to embodiments of the present invention, a method of either physically (e.g. printing) or chemically (e.g. covalent binding) attaching at least one hyperbranched polymeric mediator to an electrode (e.g. gold electrode) is provided. The attachment can be either direct attachment (e.g. grafting to the surface) or indirect attachment (e.g. sandwich structure with additional material). The additional material may comprise nanomaterials (e.g. nanotube), conductive or semi-conductive polymers (e.g. polypyrrole), metal (e.g. platinum), carbon, and any combination thereof.
[0027] According to embodiments of the present invention, an electrode with at least one immobilised hyperbranched polymeric mediator is provided which is prepared according to the above-stated method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1( a ) to ( d ) are simplified schematic depictions of 4 types of hyperbranched polymeric mediator according to embodiments of the present invention;
[0029] FIG. 2 shows a simplified schematic depiction of a reaction for synthesising a hyperbranched polymeric mediator according to an exemplary embodiment of the present invention.
[0030] FIG. 3 shows another simplified schematic depiction of a reaction for synthesising a hyperbranched polymeric mediator according to an exemplary embodiment of the present invention.
[0031] FIG. 4 shows a simplified schematic depiction of chemically direct attachment of a hyperbranched polymeric mediator to an electrode according to an exemplary embodiment of the present invention.
[0032] FIG. 5 shows a another simplified schematic depiction of chemically direct attachment of a hyperbranched polymeric mediator to an electrode according to an exemplary embodiment of the present invention.
[0033] FIG. 6 shows results of cyclic voltammetry experiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] To be consistent throughout the present specification and for clear understanding of the present invention, the following definitions are hereby provided for terms used therein:
[0035] The term “redox mediator” refers to any chemical moiety capable of undergoing a reduction or oxidisation with both an enzyme and an electrode surface.
[0036] The term “hyperbranched polymeric mediator” refers to a HBP containing a plurality of at least one kind of redox mediator.
[0037] HBPs are phenomenologically different from linear polymers (e.g. lower viscosity). They further show various advantages over dendrimers such as simplified synthesis, easy purification, high yield and reasonable cost. By the incorporation and attachment of redox mediator(s) in/on the hyperbranched polymer, it is able to generate a new material (hyperbranched polymeric mediator) with some advanced properties, such as high functionality and easy preparation, which are particularly useful for electrochemical-based sensors and enzyme-based biofuel cells to efficiently prevent the leaching of unfixed mediators from the vicinity of electrodes and facilitate the attachment to electrodes, while still maintaining the mediation activity. The mediation activity can even be improved by using a conjugated or conductive hyperbranched polymeric mediator.
[0038] Moreover, since HBPs can have the ability to encapsulate or bind guest molecules such as redox enzymes (e.g. glucose oxidase), the hyperbranched polymeric mediators will provide a new platform for reformative and stable electron shuttling because of the closer and substantial contact with guest molecules.
[0039] In addition, a hyperbranched polymeric mediator (“HBPM”) can be compatible with enzymes due to the surface of a HBP is highly functional (numerous terminal groups) with further opportunity to be modified if necessary. For example, a hyperbranched polymeric mediator (e.g. ferrocene-containing hyperbranched polyglycerol) having hydroxyl terminal groups on the surface is more hydrophilic and thus can be compatible with enzymes.
[0040] FIG. 1 is a schematic depiction of a HBPM according to embodiments of the present invention. The large circles 1 represent a hyperbranched polymer macromolecule. The small circles represent mediator moieties. In FIGS. 1 a and 1 b , there is only one kind of mediator moiety 2 . FIG. 1 a shows a HBPM in which the mediator moieties 1 are incorporated within the polymer molecule. FIG. 1 b shows an HBPM in which the mediators 2 have been anchored to the surface of a preformed polymer macromolecule 1 . FIGS. 1 c and 1 d correspond to FIGS. 1 a and 1 b respectively, but show HBPMs having two different kinds of mediator moiety 2 , 3 . According to the present invention, the suitable redox mediators may include, but are not limited to, moieties based on one or more of ferrocenyl redox mediators, ferri/ferrocyanide redox mediators, quinone redox mediators, osmium redox mediator complexes, methylene blue redox mediators, 2,6-dichloroindophenol redox mediators, thionine redox mediators, gallocyanine redox mediators, indophenol redox mediators, ethyl phenazene redox mediators, and any combinations thereof.
[0041] The redox mediator(s) can be chemically incorporated within a hyperbranched polymeric mediator via covalent bonds ( FIGS. 1 a and c ). A hyperbranched polymeric mediator can be synthesised via an A 2 +B 3 approach, where group A is readily reactive with group B in the presence of a suitable catalyst (e.g. an acid or a base). Herein, the functional redox mediator could either be A 2 or B 3 type.
[0042] For example, FIG. 2 is a simplified depiction of a reaction for synthesising a hyperbranched polymeric mediator according to an exemplary embodiment of the present invention. The reaction is a ring-opening polymerisation of an A 2 type functional redox mediator with a B 3 type functional monomer. The product is an HBP incorporating covalently attached redox mediator moieties (namely, ferrocene moieties). As will be described in the Examples below, such a hyperbranched polymeric mediator is useful in electrochemical-based glucose sensors.
[0043] The synthetic approach for a hyperbranched polymeric mediator may also include the polycondensation of an AB x (x≧2) type redox mediator, the self-condensation vinyl polymerisation of an AB* type redox mediator (* represents a reactive site which can initiate the polymerisation) and multi-branching ring-opening polymerisation of a latent AB x type redox mediator.
[0044] The redox mediator(s) can also be chemically anchored on the periphery of the HBP via surface modification ( FIGS. 1 b and d ). In other words, at least one redox mediator can be introduced and covalently bond to the surface of a prepared HBP. The functional end groups on the periphery of a HBP for such modification may include hydroxy, halide, carboxyl acid, carboxyl halide, amide, and amine groups.
[0045] One example for synthesising another hyperbranched polymeric mediator is depicted in FIG. 3 according to an exemplary embodiment of the present invention. The reaction sequence includes the initial synthesis of a HBP and subsequent surface modification via a ring-forming reaction. The system can be recognised as a HBP bearing covalently attached redox mediator moieties on the periphery (namely, ferrocene caps).
[0046] The attachment of at least one hyperbranched polymeric mediator to an electrode, according to embodiments of the present invention, can be divided into two categories: direct attachment and indirect attachment. The electrode can include carbon electrodes, metal electrodes, polymer electrodes, and any combinations (namely, hybrid electrodes) thereof. The attachment can be either physical (e.g. printing) or chemical (e.g. covalent binding).
[0047] For direct attachment, at least one hyperbranched polymeric mediator is directly immobilised on the surface of an electrode. Examples of such physically direct attachment are coating, printing, dipping and hydrophobic interaction.
[0048] An example of such chemically direct attachment via covalent bonding is depicted in FIG. 4 according to an exemplary embodiment of the present invention. Carboxylic acid groups are first introduced on the surface of a gold (Au) electrode and then converted into carbonyl chloride groups followed by a reaction with ethylene glycol to produce hydroxy end groups. A hyperbranched polymeric mediator can be initialised on these end groups (namely, graft-from approach) in accordance with the method provided in FIG. 3 . Alternatively, a preformed hyperbranched polymeric mediator can also be covalently attached to the modified surface of an electrode (namely, graft-to approach). For example, as depicted in FIG. 5 , in a two-step reaction, a synthesised HBP will firstly be attached to the carbonyl chloride groups on an Au electrode via ester links and then modified with functional redox mediators on the polymer surface according to the method described in FIG. 3 .
[0049] For indirect attachment, at least one hyperbranched polymeric mediator is indirectly immobilised on the surface of an electrode via the employment of additional material. In other words, the additional material is attached by the hyperbranched polymeric mediator in prior to its immobilisation on the electrode surface. The additional material may comprise nanomaterials (e.g. nanotube), conductive or semi-conductive polymers (e.g. polypyrrole), metal (e.g. platinum), carbon, and any combination thereof. The attachment of at least one hyperbranched polymeric mediator to the additional material and the attachment of the additional material to the electrode surface, can be physical or chemical by any suitable technique know to those of skill in the art.
[0050] While the present invention has been described with specificity in accordance with certain of its preferred embodiments, the following examples serve only to illustrate the invention and are not intended to limit the same. If sources are not specifically described materials are known and commercially available. The practice of the present invention employs, unless otherwise indicated, conventional techniques which are within the skill of the art and which are explained fully in literature.
EXAMPLES
Example 1
Synthesis of a Hyperbranched Polymeric Mediator of FIG. 2
[0051] Ferrocenedimethanol (166.80 mg), trimethylolpropane tryglicydyl ether (512 μL) and tert-butyl ammonium chloride (23.55 mg) were placed in a 5 ml vial. The mixture was heated at 120° C. in an oil bath, and stirred at a constant rate. After 22 hours, the crude product was purified by precipitating it into water after its dissolution in THF. The product was dried under vacuum for two days.
Example 2
Electrochemical Evaluation of the Hyperbranched Polymeric Mediator Synthesised in Example 1
[0052] Cyclic voltammetry (CV) was carried in μAutolab equipment with a type III potentiostat, supported with GPES software (Eco Chemie, Netherlands). A gold electrode was used as working electrode, counter electrode was a platin wire and measurements were referenced toward an Ag/AgCl reference electrode in KCl saturated solution. All the CV measurement were carried out at 150 mv/s scan rate and scanned four times for each sample.
[0053] 15 ml of phosphate buffer was prepared with pH=7.4 and a 1M glucose solution was made in this phosphate buffer. 1 ml of hyperbranched polymeric mediator product synthesised in Example 1 was then dissolved in 7 ml of THF.
[0054] The first CV measurement was carried out after adding 125 mg of glucose oxidase and 1.5 ml of glucose solution (1M) to the phosphate buffer (15 ml). Then 1 ml of hyperbranched polymeric mediator sample was added followed by the CV measurement.
[0055] A set of CV plots was determined for samples containing no polymer, and 0.5 ml, 1 ml, 1.5 ml, 2.0 ml and 2.5 ml. The curves moved to progressively higher currents as the polymer concentrations increased.
Example 3
[0056] Schiff base hyperbranched polymer was prepared by reaction of ferrocene dialdehyde (Fc—(CHO) 2 ) with N (CH 2 NH 2 ) 3 in a refluxing mixture at 80° C. with monomer ratio of 3:2 in absolute ethanol solvent. It was catalysed by amberlyst proton exchange beads and excess molecular sieves are added to remove the water produced in order to shift the equilibrium to the product side. The final polymer was made after reduction by NaBH4 and purification by a column containing Biorad beads.
[0057] CV tests were performed as in Example 2, with increased volumes of Schiff base hyperbranched polymer in a glucose/glucose oxidase system. The results are shown in FIG. 6
[0058] While the invention has been illustrated above by reference to preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended to cover all such changes and modifications by the appended claims.
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A redox mediator is a hyperbranched polymer having redox moieties (e.g. ferrocene) incorporated into its structure and/or chemically bonded to its periphery. It is attached to an electrode and assists in transferring electrons between the electrode and a redox enzyme.
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BACKGROUND OF THE INVENTION
This invention relates to vibration dampers, particularly to those of the class suitable for protection of electronic, electrical, and/or mechanical appliances from external vibrations or shocks that might be applied thereto in multiple directions, among other applications.
Vibrations and shocks are potentially detrimental to such electronic instruments as video cameras, video tape recorders, and disk drives, all with precision-made mechanical parts and components built into them. Such devices must therefore be, and indeed have been, protected by vibration dampers of one kind or another, particularly when they are going to be put to use where such vibrations or shocks are imminent or possible.
A variety of vibration dampers have been suggested and used for the above and many other purposes. Such conventional devices are all based upon the principle of either springing, viscous damping (utilizing the viscosity of a liquid), friction damping, magnetic damping, or inherent damping (rubber, felt, cork, etc.), or upon combinations of any two or more of the listed types. Dampers for the purposes of this invention are required, among other things, to be compact and inexpensive. No doubt best meeting these requirements are inherent dampers.
Conventionally, however, a majority of simple inherent dampers have not been explicitly designed to be omnidirectional, more or less equally effective in multiple directions. The truth of this statement will be acknowledged in light of the fact that the known devices of the class under consideration have had to be installed in many different locations and orientations for protecting an instrument from vibrations in as many different directions.
Another weakness of the prior art simple inherent dampers is that they mostly lack inbuilt limit stops for positively arresting the displacement of the object of protection beyond the limits within which the dampers can function as such. Combined use of external limit stops has therefore been necessary to preclude any undue displacement, which might result in damage or destruction, of the object relative to the supporting structure.
SUMMARY OF THE INVENTION
In consideration of the foregoing state of the art the present invention aims at the provision of a vibration damper of the inherent type that, although so simple and inexpensive in construction, works in multiple directions.
Another object of the invention is to incorporate limit stops within the damper of the character defined for restricting the displacement of the object of protection and the deformation of the damper beyond the limit of elasticity.
Yet another object of the invention is to protect a precision-made machine or device of any kind from multidirectional vibrations or shocks using a minimum number, typically two, of dampers each attaining the above recited objects.
Briefly, the invention may be summarized as an omnidirectional vibration damper to be mounted between an object of protection such as electronic, electrical, and/or mechanical appliances, and a support therefor. The damper comprises a carrier for rigidly carrying an object of protection, the carrier having a first portion laid parallel to a bearing surface of the support, and a second portion extending at right angles with the first portion. Also included are damping means formed from an elastic material and interposed between the support and the carrier.
Preferably, the damper according to the invention additionally comprises fastener means rigidly coupled to the support. The fastener mean comprises a first portion laid parallel to the bearing surface of the support and farther away therefrom than the first portion of the carrier, and a second portion extending at right angles with the first portion of the fastener means and concentrically through the second portion of the carrier toward the bearing surface of the support. In a preferred embodiment this second portion of the fastener means takes the form of an internally screw-threaded tube, or nut, in which a bolt is engaged for fastening the fastener means to the support. The damping means acts between the first portions of the carrier and the fastener means, between the first portion of the carrier and the bearing surface of the support, between the first portion of the fastener means and the bearing surface of the support, and between the second portions of the carrier and the fastener means.
Thus the damper of this invention can mitigate vibrations both in a plane parallel to the bearing surface of the support, in which extend the first portions of both the carrier and the fastener means, and in a direction at right angles therewith, in which extend the second portions of the carrier and the fastener means. The damper is therefore omnidirectional.
It will also be appreciated that, coupled fast to the support and partly concentrically received in the second portion of the carrier, the fastener means coacts with the support to positively limit the displacement of the carrier, and hence of the object of protection, in every possible direction.
The present invention also features an onmidirectional vibration damping system comprising only two dampers, each of the construction summarized above, for protecting a desired object. Arranged in axial alignment with each other and in positions of symmetry with respect to the center of mass of the object, the minimal number of dampers can nevertheless effectively protect the object from multidirectional vibrations or shocks.
The above and other objects, features and advantages of this invention and the manner of achieving them will become more apparent, and the invention itself will best be understood, from a study of the following description and attached claims, with reference had to the accompanying drawings showing the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view, taken through the line A—A in FIG. 2, of an electronic instrument as supported by the vibration damping system according the present invention;
FIG. 2 is a plan view of the showing of FIG. 1;
FIG. 3 is an exploded perspective view, partly shown broken away, of one of the pair of vibration dampers included in the FIG. 1 damping system;
FIG. 4 is an exploded axial section, partly shown broken away, of one of the pair of vibration dampers included in the FIG. 1 damping system;
FIG. 5 an axial section through a modified set of damping rings;
FIG. 6 is an axial section through another modified set of damping rings;
FIG. 7 is an axial section, with parts shown broken away, through another preferred form of vibration damper according to the invention;
FIG. 8 is a view similar to FIG. 1 but showing a modified vibration damping system according to the invention;
FIG. 9 is also a view similar to FIG. 1 but showing another modified vibration damping system according to the invention; and
FIG. 10 is a fragmentary axial section through a modified carrier for use in vibration dampers according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail as applied to the protection of an electronic instrument. In FIGS. 1 and 2 is shown an electronic instrument 1 mounted via a pair of vibration dampers 2 and 3 to a support 4 . The invention is specifically directed to the construction of each vibration damper 2 or 3 as well as to the vibration control system comprising both dampers. Since the two vibration dampers 2 and 3 are identical in construction, only one of them, 2 , will be detailed, it being understood that the same detailed description applies to the other, 3 .
The construction of the representative damper 2 will be understood by referring also to FIGS. 3 and 4 which illustrate its component parts on an enlarged scale. The damper 2 comprises, in addition to the support 4 which is shared by both dampers 2 and 3 and which may be considered a part of each damper for the purposes of this invention, a carrier 5 coacting with its counterpart 5 of the other damper 3 for rigidly carrying the electronic instrument 1 , fastener means 8 including a fastener element shown as a screw or bolt 9 , and two damping rings 6 and 7 acting between the support 4 and the carrier 5 , between the support 4 and the fastener means 8 , and between the carrier and the fastener means.
Boxlike or tubular in shape and thoroughly enclosing the instrument 1 and the dampers 2 and 3 , the support 4 is made from sheet metal and is sturdy enough to protect the instrument, resisting shocks and pressures that are likely to be exerted thereon in use. All but the two damping rings 6 and 7 of the component parts of the damper 2 are metal made. The damping rings 6 and 7 are molded from any such elastic materials as natural and synthetic rubbers or elastomers typically including silicone in the form of gel or jelly.
As revealed by FIG. 1, the carrier 5 is generally U shaped as seen in this figure, including a flat web 10 with a tubular boss 11 , and a pair of flanges 12 bent right-angularly from the web and screwed or otherwise secured to the instrument 1 . The web 10 is laid parallel to the bearing surface 4 a of the support 4 . As will be noted also from FIGS. 3 and 4, the tubular boss 11 on the web 10 projects right-angularly therefrom in a direction away from the bearing surface 4 a of the support 4 . This hollow boss 11 may be formed either by stamping of the sheet metal of which the carrier 5 is made or by welding a short tube to the sheet metal.
The fastener means 8 with the screw or bolt 9 function to fasten the carrier 5 to the support 4 via the damping rings 6 and 7 . Included are a nut or internally screw-threaded tube 22 with an outside diameter less than the inside diameter of the tubular boss 11 of the carrier 5 , and a flange 23 of disklike shape formed on one end of the nut 22 . The nut 22 extends concentrically and with substantial clearance through the hollow boss 11 of the carrier 5 and, in this particular embodiment of the invention, has one end held against the bearing surface 4 a of the support 4 . Formed on the other end of the nut 22 , the flange 23 is parallel to the bearing surface 4 a of the support 4 and farther away therefrom than the web 10 of the carrier 5 .
The bolt 9 is engaged in the nut 22 from outside the support 4 through a hole 25 created therein. The nut 22 with the flange 23 is therefore rigidly coupled to the support 4 .
FIGS. 3 and 4 also best illustrate the two damping rings 6 and 7 . The first damping ring 6 is a coaxial, one-piece construction of a larger diameter portion 14 and a smaller diameter portion 15 , with a hole 16 extending axially through both portions. Having a surface 18 held against the bearing surface 4 a of the support 4 , the larger diameter portion 14 of the first damping ring 6 surrounds part of the nut 22 of the fastener means 8 and partly engaged between the bearing surface 4 a and the web 10 of the carrier 5 . Projecting from the other surface 17 of the larger diameter portion 14 , the smaller diameter portion 15 surrounds part of the nut 22 of the fastener means 8 and surrounded by the hollow boss 11 of the carrier 5 . The diameter of the hole 16 in this first damping ring 6 is approximately equal to the outside diameter of the nut 22 , so that the first damping ring relatively closely fits over the nut.
The second damping ring 7 is a simple ring having a pair of opposite surfaces 19 and 20 and a hole 21 extending axially therethrough. Having an inside diameter approximately equal to the outside diameter of the hollow boss 11 of the carrier 5 , the second damping ring 7 fits over that hollow boss and is engaged between the web 10 of the carrier 5 and the flange 23 of the fastener means 8 .
Referring specifically to FIG. 4, the axial dimension H 1 of the hollow boss 11 of the carrier 5 is less than the axial dimension H 2 of the smaller diameter portion 15 of the first damping ring 6 and also than the axial dimension H 3 of the second damping ring 7 . The axial dimension H 2 of the smaller diameter portion 15 of the first damping ring is approximately equal to the axial dimension H 3 of the second damping ring 7 plus the thickness of the web 10 of the carrier 5 . Thus, as will be seen by referring back to FIG. 1, the hollow boss 11 of the carrier 5 is spaced from the flange 23 of the fastener means 8 .
Before the damper 2 is assembled and mounted in position as shown in FIG. 1, the axial dimension H 4 of the nut 22 of the fastener means 8 is less than the axial dimension H 5 of the first damping ring 6 . The first damping ring 6 is compressed, however, to the same dimension as the nut 22 when the bolt 9 is fully driven into the nut as in FIG. 1 .
In assembling and mounting the damper 2 , the carrier 5 may be fastened to the electronic instrument 1 either before or after the two damping rings 6 and 7 are mounted to the carrier. The smaller diameter portion 15 of the first damping ring 6 may be inserted in the hollow boss 11 of the carrier 5 , which has been, or is not yet, fastened to the instrument 1 , until the surface 17 of the larger diameter portion 14 hits the web 10 of the carrier. Then the second damping ring 7 may be fitted over the carrier boss 11 so that the surface 20 of the ring rests against the web 10 . Then the nut 22 of the fastener means 8 may be inserted in the hole 16 in the first damping ring 6 from its smaller diameter portion 15 until the flange 23 on the nut comes into abutment against the ends of both first 6 and second 7 damping rings.
Next comes the step of mounting the damper 2 to the support 4 , it being understood that the instrument 1 has already been attached to the carrier 5 . With the surface 18 of the first damping ring 6 held against the bearing surface 4 a of the support 4 , the bolt 9 may be driven into the nut 22 via the hole 25 in the support until the nut 22 comes to butt on the bearing surface 4 a. Although greater in axial dimension than the nut 22 as aforesaid, the first damping ring 6 will be compressed as the bolt 9 is driven into the nut and become equal in axial dimension to the nut when this nut comes into abutment against the bearing surface 4 a of the support 4 .
Now has been completed the assemblage and mounting of the damper 2 . The other damper 3 may be assembled and mounted in place in a like manner. The completion of the mounting of both dampers 2 and 3 is tantamount to the elastic, vibration-proof mounting of the instrument 1 to the support 4 .
A reconsideration of FIG. 1 will show that the web 10 of the carrier 5 is caught between the larger diameter portion 14 of the first damping ring 6 and the second damping ring 7 . Since the hollow boss 11 of the carrier 5 is normally spaced from the flange 23 of the fastener means 8 , the damping rings 6 and 7 are capable of elastic deformation in both directions along the z-axis indicated in FIG. 1 .
The hollow boss 11 of the carrier 5 , on the other hand, is sandwiched between the smaller diameter portion 15 of the first damping ring 6 and the second damping ring 7 . These damping rings are therefore elastically deformable in any direction in a plane containing the x- and y-axes in FIG. 1 . Thus the damper 2 can protect the instrument 1 from triaxial vibrations and shocks.
FIG. 1 further indicates that only a minimal number, two, of dampers 2 and 3 are used for protecting the instrument 1 by virtue of their omnidirectional damping capabilities. For most effectively guarding the instrument 1 the two dampers 2 and 3 are arranged in axial alignment with each other in positions on symmetry along a notional line 27 extending through the center of mass 26 of the instrument 1 . Being effective in both vertical and horizontal directions, the two aligned dampers 2 and 3 will favorably protect the instrument 1 from vibrations that might be applied thereto in any direction.
The following is a list of advantages gained by the specific embodiment of the invention disclosed above:
1. The damper 2 , though so simple and inexpensive in construction, is thoroughly tridimensional in its effectiveness.
2. Rigidly coupled to the support 4 , the fastener means 8 function as stops for limiting the displacement, and preventing the destruction, of the damping rings 6 and 7 .
3. The carrier 5 , damping rings 6 and 7 , and fastener means 8 are all concentric with one another, so that they can be readily assembled by interfitting them sequentially.
4. The component parts of the damper 2 are inseparably coupled together, and the damper mounted in position between carrier and support, simply as the bolt is driven into the flanged nut.
5. The degree of elasticity of the damper in any of the x-, y- and z-axes is adjustable by changing the pertinent dimensions of the damping rings 6 and 7 .
6. Only two dampers 2 and 3 are needed to protect the instrument 1 from omnidirectional vibrations.
Second Form
A second preferred form of vibration damper according to the invention features a modified first damping ring 6 a , FIG. 5, which is for use in the first disclosed damper 2 or 3 in substitution for the first disclosed first damping ring 6 . The modified first damping ring 6 a is divided into a larger diameter member 14 a and a smaller diameter member 15 a , both having holes 16 a and 16 b of the same diameter. The two ring members 14 a and 15 a can be molded from the same material or from different materials.
In assembling and mounting the damper incorporating the modified first damping ring 6 a , the smaller diameter ring member 15 a may first be inserted in the hole 13 , FIG. 4, in the web 10 of the carrier 5 . Then the second damping ring 7 may be fitted over the hollow boss 11 of the carrier web 10 . Then the nut 22 of the fastener means 8 may be inserted in and through the hole 16 b in the smaller diameter ring member 15 a and then in the hole 16 a in the larger diameter ring member 14 a. The rest of the procedure is as set forth above in connection with the first embodiment of the invention.
The damper with the divided first damping ring 6 a is just as effective as that including the integral first damping ring 6 . The fabrication of two simple ring members of different diameters is nevertheless easier than that of the integral ring of two different diameter portions. As required or desired, moreover, different materials with different elasticities may be employed for the two ring members 14 a and 15 a in each specific application of the invention.
Third Form
In FIG. 6 is shown another modified first damping ring 6 b , also for use in the first disclosed damper 2 or 3 in place of the first damping ring 6 . This second modification is similar to the first modified damping ring 6 a in that the ring is divided into a larger diameter member 14 b and a smaller diameter member 15 b , but differs therefrom in that the larger diameter member 14 b has a hole 16 a large enough to receive the smaller diameter member 15 b. This smaller diameter member 15 b has a hole 16 c extending axially therethrough just like the hole 16 in the FIG. 4 damping ring 6 . The axial dimension H 5 of the smaller diameter member 15 b is the same as that of the damping ring 6 , and the dimension H 2 of that part of the smaller diameter member 15 b which projects from the larger diameter member 14 b is the same as that of the smaller diameter portion 15 of the damping ring 6 .
This second modified damping ring 6 b gains the same advantages as does the FIG. 5 damping ring 6 a.
Fourth Form
FIG. 7 represents a further modified vibration damper 2 a according to the invention, featuring a one-piece construction 6 c of what are shown in FIGS. 1-4 embodiment as the first 6 and second 7 damping rings. Thus the integral damping ring 6 c is shaped like the combination of these first disclosed damping rings 6 and 7 , that is, a cylinder having a hole 16 c′ extending axially therethrough, the hole being equivalent to the hole 16 in the first damping ring 6 . The nut 22 is received in the hole 16 c′.
It will be also noted from FIG. 7 that the integral damping ring 6 c is molded in place on the carrier 5 , enveloping its hollow boss 11 and the neighboring part of the web 10 . This is possible by the familiar insert molding method.
In FIG. 7 is further shown an electronic circuit board 30 mounted on the web 10 of the carrier 5 . This showing represents an additional possible use of the invention.
Fifth Form
In each of the dampers 2 b and 3 b shown in FIG. 8 the hollow boss 11 of the carrier 5 extends from the web 10 toward the bearing surface 4 a of the support 4 , instead of away from the bearing surface as in all the foregoing embodiments. In conformity with this modified carrier configuration the two damping rings 6 and 7 are reversed in position. Thus the first damping ring 6 has its larger diameter portion 14 surrounding part of the nut 22 of the fastener means 8 and partly engaged between the web 10 of the carrier 5 and the flange 23 of the fastener means 8 , and its smaller diameter portion 15 surrounding the rest of the nut 22 and surrounded by the hollow boss 11 of the carrier 5 . The second damping ring 7 surrounds the hollow boss 11 of the carrier 5 and is engaged between the bearing surface 4 a of the support 4 and the web 10 of the carrier 5 .
This embodiments provides the advantage that the first damping ring 6 can be molded in one piece with the fastener means 8 for greater use of assemblage.
Sixth Form
The dampers 2 c and 3 c seen in FIG. 9 have each damping rings 6 ′ and 7 ′ of greater axial dimensions, relative to the nut 22 of the fastener means 8 , than their counterparts 6 and 7 of all the previous embodiments. Consequently, the nut 22 of the fastener means 8 is spaced from the bearing surface 4 a of the support 4 , unlike the foregoing embodiments in which the nut contacts the bearing surface.
The provision of the spacing between support 4 and nut 22 is preferable in cases where the damping rings 6 ′ and 7 ′ in use are not sufficiently elastic for omnidirectionally alleviating vibrations by making them immovable relative to each other. The provision of a similar spacing is also possible in the embodiments of FIGS. 7 and 8.
Seventh Form
FIG. 10 fragmentarily illustrates a modified carrier 5 a having a hollow boss 11 a extending toward the bearing surface, not shown here, of the support in addition to that 11 extending away therefrom. The boss 11 a should be spaced from the bearing surface like that of FIG. 8 . The modified carrier 5 a may be employed in combination with one damping ring with an outside diameter to fit in the hollow bosses 11 and 11 a and two other damping rings with an inside diameter to fit over these hollow bosses.
Possible Modifications
Notwithstanding the foregoing detailed disclosure it is not desired that the present invention be limited by the exact showing of the drawings or the description thereof. The following, then, is a brief list of possible modifications or alterations of the illustrated embodiments:
1. Only one or three or more dampers, instead of two as in the foregoing embodiments, may be employed for supporting a desired object of protection.
2. The hollow boss 11 on the web 10 of the carrier 5 , which is shown as a tube in all the illustrated embodiments, could take other forms such as, for instance, a plurality of fingers of annular or similar arrangement defining a space for the passage of the smaller diameter portion 15 of the first damping ring 6 , or an equivalent part of the other first damping rings 6 a , 6 b and 6 c disclosed.
3. The unitary support 5 may be divided into two or more discrete members each having an end portion bent right-angularly to serve as the noted fingers of annular or like arrangement.
All these and other changes of the illustrated embodiments are intended in this disclosure. It is therefore appropriate that the invention be construed broadly and in a manner consistent with the fair meaning or proper scope of the annexed claims.
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An omnidirectional vibration damping system comprising a pair of dampers of identical make mounted between a carrier rigidly carrying an electronic instrument or like object of protection and a rigid support therefore, the dampers being positioned in axial alignment with each other in positions of symmetry with respect to the center of mass of the object. The carriers have webs laid parallel to a pair of opposed bearing surfaces of the support, each web having formed thereon a hollow boss extending at right angles therefrom. Each damper has a nut extending with clearance through the hollow boss of one carrier and having one end held fast against the bearing surface of the support by receiving a bolt from outside the support. Formed on the other end of the nut is a flange laid parallel to the bearing surface and farther away therefrom than the carrier web. Two damping rings of elastic material and preformed shapes act between nut flange and carrier web, between carrier web and support, between nut flange and support, and between nut and carrier boss, thereby mitigating vibrations both in a plane parallel to the each bearing surface of the support and in a direction at right angles therewith.
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FIELD OF THE INVENTION
Fictitious forces are additional forces that appear in rotating reference frames. These forces are difficult to explain. The present invention provides a mechanism far from equilibrium and producing rotation over an axis for demonstrating the function of these forces on spherical bodies. The mechanism explains how random fluctuations of vibrating strings or beams can become coherent when producing these additional pseudo forces.
BACKGROUND
A beam is a structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads is called a bending moment.
The magnitude of the bending moment along the length of a beam varies depending on the location and type of supports on which the beam is located. A positive bending moment induces compressive forces above the neutral axis, while tensile forces are induced in the material below the neutral axis. The compressive and tensile forces result in shortening and lengthening of the material respectively above and below the neutral axis. Internally, beams experience compressive, tensile and shear stresses as a result of the loads applied to them
By stretching and bending/contracting a resting beam the section between supports of the beam, called span, varies in length. The span is a significant factor in finding the strength and size of a beam as it determines the maximum bending moment and deflection.
There is a mechanical energy required to disassemble a beam or any other object into separate parts that is called binding energy. Binding energy represents the mechanical work which must be done in acting against the forces which hold an object together while disassembling the object into component parts. By stretching and bending a resting beam the binding energy of the beam is affected.
A beam can vibrate or oscillate about an equilibrium point. The oscillations may be periodic or can be random. Damping dissipates the energy and therefore the oscillating beam will eventually come to rest. A mechanical system set off with an initial input vibrates freely at one or more of its natural frequencies and damp down to zero. When an alternating force or motion is applied to a mechanical system the frequency of the vibration is the frequency of the force or motion applied, with order of magnitude being dependent on the actual mechanical system.
A vibration in a string is a wave. Usually a vibrating string produces a sound whose frequency in most cases is constant. Therefore, since frequency characterizes the pitch, the sound produced is a constant note. The provided apparatus consists of a “string vibration mechanism”.
SUMMARY OF INVENTION
The theories of equilibrium and the effect of forces such as coriolis and centrifugal forces on equilibrium and the motion of spheres and pseudo forces can be difficult to visualize and understand. Furthermore, because of the physical world in which we live, the effect of friction on such motion also has importance.
We will describe a mechanism that uses the binding energy of a set of bent beams in combination with a selected frequency of vibration, and the input of centrifugal and coriolis forces to induce rotation to a central axle. In a combustion engine the ignition of a fuel and the resulting expanding gas in the cylinder transfers force to the crankshaft via the piston and connecting rod, to convert reciprocating motion into rotating motion. Our mechanism utilizes the energy from a set of twelve bent or contracted beams or rods substantially corresponding to the edges of a cube with each end of three groups of beams connecting to crank means corresponding to the corners of the cube, so that when they stretch to augment their span, they experience a reciprocating movement that is transferred to rotating motion through the set of crank means attached to eight shafts synchronized by an octagear, with this octagear acting as the crankshaft in an engine, imparting rotation to a selected central axle.
It is therefore an object of the present invention to provide a mechanism for demonstrating the theories of equilibrium on spherical motion.
It is a further object to provide a mechanism for teaching the symmetrical flow of energy around a spherical body in the form of motion of a center of mass.
It is a still further object to provide a mechanism to explain the function of coriolis and centrifugal forces on a rotating mass.
It is an even further object to provide a mechanism to explain the axis of rotation of a spherical body.
Further objects and advantages will become evident by reference to the following description and drawings.
The present invention provides an apparatus for teaching various concepts related to equilibrium, symmetry of energy flow and spherical motion and comprises a mechanism having a centrally located octagear made up of eight engaging bevel gears each having a central axis that is at a 70° angle relative to it's adjacent gears. Each gear has a shaft extending centrally therefrom and outward away from the octagear, with each shaft being identical in length. Toward the end of each shaft is a crank mechanism whereby reciprocating motion delivered to the crank mechanism is translated into rotary motion of the shaft about its longitudinal axis, this rotary motion being transmitted to the gear at the end of the shaft. Connecting the crank mechanisms of each shaft are a plurality of beams with each beam spanning the space between two crank mechanisms. Each beam is capable of flexing between a first curved position and a second curved position effectively resulting in a change in the span length of the beam and thereby generating a reciprocatory motion which is transmitted to the crank mechanisms.
Within the mechanism is a cube shaped frame (or any form that keeps the gears aligned with the spacediagonals of a cube) with the corners of the cube corresponding to each of the eight shafts extending from the octagear. Each shaft extends through a corner of the cube which is provided with a bearing means to permit the shaft to freely rotate therein. The cube frame is preferably located toward the outer ends of the shafts and provides support and rigidity to the mechanism.
In a first embodiment of the apparatus the beams are capable of vibrating between a first curvature of a short radius and a second curvature of a long radius without passing through a straight-line position. In this embodiment, the beams connect crank mechanisms at the outer ends of the shafts outside of the cube frame. In a second embodiment, the beams vibrate between a first curvature having an outer short radius and a second curvature having an inner short radius and passing through a straight-line position. In this embodiment, the beams connect crank mechanisms located inward of the outer ends of the shafts and the cube frame connects the outer ends of the shafts such that the vibrating beams are located within the cube confines.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a first rotational axle perpendicular to the ground.
FIG. 2 illustrates the positioning of the octagear in the middle of the first rotational axis.
FIG. 3 illustrates the octagear with eight shafts extending outwardly from corresponding bevel gears of the octagear with each shaft having a leverarm in the form of a plate at the outermost end thereof.
FIG. 4 illustrates a frame which keeps the outermost ends of the shafts aligned with the rotational axes of the octagear.
FIG. 5 illustrates the placement of offset crankpins located at the leverarms of the shafts.
FIG. 6 illustrates a complete first embodiment of the present invention.
FIG. 7 illustrates the stretching A, contracting B and neutral C loads and cycle moments for the beams placed between and joining neighbor crankpins. Each ring at the crankpins is attached to three beams extending in opposite directions.
FIG. 8 a illustrates a selected beam to describe the short span position of a beam.
FIG. 8 b illustrates the beam of FIG. 8 a with the involved shafts attached to the octagear. The arrows show the trajectory of the rotation of the shafts to reach the long span position.
FIG. 8 c explains in a two dimensional scheme the three dimensional action and positioning described in FIGS. 8 a and 8 b.
FIG. 9 a illustrates a selected beam to describe the long span position of a beam.
FIG. 9 b illustrates the beam of FIG. 9 a with the involved shafts attached to the octagear. The arrows show the trajectory of the rotation of the shafts to reach the short span position of FIG. 8 b.
FIG. 9 c explains in a two dimensional scheme the three dimensional action and positioning described in 9 a and 9 b.
FIG. 10 a illustrates the position and direction of the twelve beams describing moment # 1 of the cycle.
FIG. 10 b illustrates the position and direction of the twelve beams describing moment # 2 of the cycle.
FIG. 10 c illustrates the position and direction of the twelve beams describing moment # 3 of the cycle.
FIG. 11 a illustrates a set of four beams with the same loads describing the stretching moment of a spin cycle.
FIG. 11 b illustrates a selected beam of the four stretching beams with the involved shafts attached to the octagear. The arrows show the trajectory of the rotation of the shafts that goes from the end of the neutral cycle to the beginning of the contracting cycle.
FIG. 11 c explains in a two dimensional scheme the three dimensional action and positioning described in FIGS. 11 a and 11 b . The first scheme of the row is represented in FIG. 11 b.
FIG. 12 a illustrates a set of four beams with the same loads describing the contracting moment of a spin cycle.
FIG. 12 b illustrates a selected beam of the four contracting beams with the involved shafts attached to the octagear. The arrows show the trajectory of the rotation of the shafts that goes from the end of the stretching cycle to the beginning of the neutral cycle.
FIG. 12 c explains in a two dimensional scheme the three dimensional action and positioning described in FIGS. 12 a and 12 b . The first scheme of the row is represented in FIG. 12 b.
FIG. 13 a illustrates a set of four beams with the same loads describing the neutral moment of a spin cycle.
FIG. 13 b illustrates a selected beam of the four neutral beams with the involved shafts attached to the octagear. The arrows show the trajectory of the rotation of the shafts that goes from the end of the contracting cycle to the beginning of the stretching cycle.
FIG. 13 c explains in a two dimensional scheme the three dimensional action and positioning described in FIGS. 13 a and 13 b . The first scheme of the row is represented in FIG. 13 b.
FIGS. 14 a and b illustrate a front view and a corresponding top view of moment # 1 of the cycle according to FIG. 10 a.
FIGS. 15 a and b illustrate a front view and a corresponding top view of moment # 2 of the cycle according to FIG. 10 b.
FIGS. 16 a and b illustrate a front view and a corresponding top view of moment # 3 of the cycle according to FIG. 10 c.
FIG. 17 illustrates the described mechanism with additional supports as selected in an embodiment to be used as a teaching aid.
FIG. 18 illustrates a second embodiment of the present invention.
FIGS. 19 a and b illustrate a first moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 20 a and b illustrate a second moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 21 a and b illustrate a third moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 22 a and b illustrate a fourth moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 23 a and b illustrate a fifth moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 24 a and b illustrate a sixth moment of a six stroke cycle of a device according to the second embodiment.
FIGS. 25 a, b and c schematically illustrate the three sets of beams and their respective crankshafts in contracting, neutral and stretching moments.
FIGS. 26 a, b and c schematically illustrate equatorial beam groups corresponding to three moments of the six stroke cycle of the second embodiment.
FIGS. 27 a - f illustrate the six moments of a cycle of the second embodiment when viewed from above.
FIGS. 28 and 29 are graphical representations of the load forces on the beams during a six stroke cycle of the mechanism.
FIGS. 30-32 illustrate in two dimensions the three dimensional rotation of the shafts and axle of the second embodiment in the first of six strokes.
DESCRIPTION
In a support frame 100 we define a selected rotational axis through axle ( 1 ), see FIG. 1 , and we place an octagear ( 2 ), see FIG. 2 , in the middle so that two of its opposed bevel gears ( 20 ) are attached to the axle ( 1 ) which extends through octagear ( 2 ), the ends of axle ( 1 ) being rotationally connected to support frame 100 in a manner to be described. The octagear ( 2 ) consists of eight bevel gears ( 20 ), each gear engaging three neighbor gears, where the central axes of rotation of neighbor gears intersect and work at about 70 degree angles. The octagear ( 2 ) provides four pairs of opposed gears, each pair aligned with a different space diagonal of a cube. When the set of eight bevel gears ( 20 ) works together in a synchronized manner, four of the gears run in one direction and the other four run in the opposite direction. Provided that a cube consists of two inscribed tetrahedrons, whereby one tetrahedron's base coincides with four corners of the cube and the second tetrahedron's base coincides with the other four corners of the cube, the position of the bevel gears ( 20 ) rotating in one direction coincide with the apex of the first tetrahedron and the gears ( 20 ) revolving in the other direction coincide with the apex of the second tetrahedron. This arrangement is shown in FIG. 4 .
In addition to axle ( 1 ) which passes through two opposing bevel gears ( 20 ) and is substantially perpendicular to the ground, six outward extending shafts ( 3 ) are attached to the remaining bevel gears ( 20 ) of the octagear ( 2 ), see FIG. 3 . These six shafts ( 3 ) have an angle of about 70 degrees relative to axle ( 1 ) which is perpendicular to the ground and extends and connects together to the inner part of the octagear ( 2 ), thereby defining the selected rotational axis of the mechanism.
Alternatively, for teaching purposes, axle ( 1 ) may be other than perpendicular to the ground. For example it may be given an angle of 23° similar to the axis of the Earth. In addition, axle ( 1 ) may comprise two separate shafts ( 3 ) rather than a single shaft extending through the octagear ( 2 ) in which case the bevel gears ( 2 ) may be supported and rotate on a central member such as a sphere.
At the external end of each of the shafts ( 3 ) and axle ( 1 ) are provided crankpins ( 4 ) offset relative to the axes of the shafts ( 3 ) and axle ( 1 ) to impart motion to the shafts ( 3 ) and axle ( 1 ) when a particular force is acting on them. The crankpins ( 4 ) may be attached to the shafts ( 3 ) and axle ( 1 ) by lateral arms extending at right angles to the shafts ( 3 ) and axle ( 1 ). Preferably axle ( 1 ) and each shaft ( 3 ) is provided with a plate ( 21 ) at their free ends with the plane of plate ( 21 ) being perpendicular to the longitudinal axis of its respective shaft ( 3 ) or axle ( 1 ). Crankpins ( 4 ) are keyed to plates ( 21 ) as shown in FIG. 5 and the crankpins ( 4 ) of axle ( 1 ) are, in turn, keyed to corresponding plates ( 22 ) attached to rotational mounts ( 101 ) on frame ( 100 ) to permit transfer of the energy output to do work in the outer part of the mechanism. Alternatively, mounts ( 101 ) may be fixed, in which case all energy will be transferred into rotation of the mechanism within the support frame ( 100 ).
The crankpins ( 4 ) are bearing surfaces whose axis is offset from that of the shaft and to which the ends of the beams ( 5 ) are attached. When the beams stretch and contract in a reciprocating manner, the crankpins ( 4 ) translate that reciprocating motion into rotation, applying torque to the shafts ( 3 ). Since each one of the shafts ( 3 ) is attached to a bevel gear ( 20 ) of the octagear ( 2 ), that rotational motion is transferred by the action of those gears ( 20 ) to the central axle ( 1 ) to be used as energy output or as rotation of the mechanism.
In order to permit rotation of the crankpins ( 4 ) in response to the reciprocation of the beams ( 5 ), the ends of the beams ( 5 ) are attached to a ring or bushing ( 23 ) that goes around the crankpins ( 4 ). Since the ends of the beams ( 5 ) push outward at the rings ( 23 ), bearings or similar means should provide the connection between the ring ( 23 ) and the crankpin ( 4 ) allowing for the beams ( 5 ) to turn the shafts ( 3 ). In addition, the attachment of the beams ( 5 ) to the ring or bushing ( 23 ) is preferably by a means which will accommodate the inherent reciprocating and rotational motion which occurs at the ends of the beams as they move through their cycle of operation. Such means may include ball and socket or other suitable universal-type joints. The crankpins ( 4 ) are fixed onto the end of the crankarm or plate ( 21 ) and three beams ( 5 ) rest and are attached to each of the rings ( 23 ) around the crankpins ( 4 ) in such a way that the ring ( 23 ) is free to rotate on bearings with respect to the crankpin ( 4 ) but is attached to it. The bearing surface between the rings ( 23 ) and the crankpins ( 4 ) may be any structure suitable including, but not limited to, ball bearing or roller bearing assemblies, low friction materials such as nylon or ceramic bushings, or the like. The beams ( 5 ) resist bending by stretching and thereby pushing the crankpins ( 4 ) to propel the shafts ( 3 ). The shafts ( 3 ) experience stress from the reciprocating load represented by the stretching and bending beams ( 5 ), coming from three different directions due to the three different beam ends attached to the rings ( 23 ) at each of the crankpins ( 4 ). As the shafts ( 3 ) undergo sideways load from the beams ( 5 ), they must be supported by a rigid frame ( 6 ) which is preferably in the form of a cube, the corners of that cube providing eight bearings ( 24 ) adjacent to and inward of the plates ( 21 ) through which the shafts ( 3 ) and axle ( 1 ) pass. The axes of the beatings ( 24 ) are aligned with the rotational axes of the shafts ( 3 ) and axle ( 1 ), allowing the shafts ( 3 ) and axle ( 1 ) to rotate freely while being attached to the frame ( 6 ) keeping said shafts ( 3 ) and axle ( 1 ) aligned with the rotational axes of their corresponding bevel gears ( 20 ) of octagear ( 2 ) as shown in FIGS. 4-7 . As with the rings ( 23 ) on the crankpins ( 4 ), the bearings ( 24 ) of the frame ( 6 ) may be any structure suitable including, but not limited to, ball bearing or roller bearing assemblies, low friction materials such as nylon or ceramic bushings, or the like, even a plain hole and grease may work.
The magnitude of the rotational force applied to the shafts ( 3 ) by the reciprocating force of the stretching and contracting beams ( 5 ) varies depending on the moment of force that the beam ( 5 ) experiences through any given cycle. The span of the arched beam ( 5 ) is the longest when the beam ( 5 ) stretches. The resisting bending force of the stretching beam ( 5 ) is doing the mechanical work, by applying torque to the shafts ( 3 ) via the leverarms or plates ( 21 ) at the crankpins ( 4 ). The selected material of the beam ( 5 ), the selected bending angle of the beam ( 5 ) and the distance from the crankpin ( 4 ) axis to the shaft ( 3 ) axis determines the magnitude of the torque. FIG. 9 b , shows the stretched position of a beam ( 5 ). In order for the mechanism to work the beam ( 5 ) needs to show at least a minimal radius of curvature in stretched position, otherwise if the beam ( 5 ) adopts a straight-line in stretched position the mechanism locks down, although in a second embodiment of the present invention we will see how the beams ( 5 ) may pass through a straightline stretched position from an outer contracted position to an inner contracted position producing rotation of the device in a six moment cycle.
The span of the arched beam ( 5 ) is the shortest when the beam contracts. FIG. 8 b , shows the contracted position ( 7 ) of a beam ( 5 ) which causes the corresponding crankpins ( 4 ) to which the beam ( 5 ) is attached to rotate around to their closest relative position. A contracted beam position ( 7 ), FIG. 8 a,b,c , adopts a smaller radius of curvature than a stretched beam position ( 8 ), FIG. 9 a, b, c . Motion is imparted to the mechanism when a force is acting on the crankpins ( 4 ) to rotate the shafts ( 3 ). But the function can also be reversed when the force is transferred from the rotational motion of the shafts ( 3 ) to the beams ( 5 ), resulting in a contraction of the beam ( 5 ). This is the case when the beams ( 5 ) go from stretched position ( 8 ) to contracted position ( 7 ). The trajectory of the crankpins ( 4 ) in this case is represented by the arrows in FIG. 9 c . We will see below that this type of reversed function occurs when the combined loads of four stretching beams is level with the loads of four contracting beams, while the other four beams remain in neutral position. The combination of loads is possible due to the central octagear ( 2 ) synchronizing all of the eight shafts ( 1 , 3 ) of the device.
The initial position or the orientation of the crankpins ( 4 ) with respect to the rest of the pins defines the bending moments and corresponding loads of each beam ( 5 ) and thereby determines the ability of the mechanism to do work when the twelve preloaded bent beams ( 5 ) are let loose in the mechanism to apply torque to the leverarms. See FIG. 6 . We describe these initial positions based on the positioning of the numbers of game dice. FIGS. 8 a and 9 a show a die inside the cubic frame ( 6 ) with numbers 1, 2 and 3 exposed. The positioning of the numbers 4, 5 and 6 can be determined by the rule stating that opposing faces of a die must sum 7 . By selecting the initial position of the die with the numbers 3, 2 and 6 in the upper hemisphere and the numbers 1, 4 and 5 in the southern hemisphere we can define a three digit number for each of the corners of the cube ( 6 ) and thereby we can easily find a coordinate for each of the crankpins ( 4 ). For example, the number 132 describes the vertices of the cube where numbers 1, 3 and 2 meet, but this number also describes the spinning direction of this particular pin coming from face 1 of the cube and rotating in direction 3 and then 2. With this same logic in mind we can deduce that in the same FIGS. 13 b and 13 c the crankpin at 513 is rotating in the opposite direction first 5, then 1 and then 3. Opposed extremes of beams rotate in opposed directions, to allow proper rotation of the octagear ( 2 ). If we imagine the cube in FIGS. 8 a and 9 a is a terrestrial globe, by convention, just by looking at the numbers of the selected beam 132-513, we should be able to determine that pin 132 is turning West/East/South and pin 513 is turning in opposite direction West/North/East.
Following the same example of FIG. 9 a , the selected beam 132-513 extends along side 13 of the cube, the side number being determined by the union of faces 1 and 3 of the imaginary die. The arrows in the scheme of FIG. 9 c , describe pin 132 starting at side 21 and rotating until reaching mid side 3 of the die. Accordingly pin 513 starts at side 35 and ends its trajectory in mid side 1. As a visual guide, the vertices of the triangles in FIG. 9 b correspond to the lines that divide one die number from the other in the scheme of FIG. 9 c . The trajectory from a pin position at the longest span, corresponding to stretched position ( 8 ) ( FIG. 9 ) to a pin position at the shortest span, corresponding to a contracted position ( 7 ) ( FIG. 8 ), describes the reciprocating movement of the beams ( 5 ) based on two opposed and extreme positions: stretched and contracted.
It is important to point out that the pin positions of FIGS. 8 and 9 are very different from the ones we will describe next, referring to the three different stroke moments described in FIGS. 10 , 11 , 12 and 13 . This difference is due to the fact that although the reciprocating movement has two extreme positions (long ( 8 ) and short ( 7 )), the stroke cycle for each revolution of the pin has three different moments corresponding to the loads carried from three different beams ( 5 ) at a particular point in time by each pin.
Every degree of rotation on a given pin puts the octagear ( 2 ) in motion and with every little rotation of the pins the configuration of the loads of the beams ( 5 ) is altered. We will see how the symmetry of the mechanism allows one to understand the functioning of the entire cycle of the beams ( 5 ) by analyzing only one third of the rotation.
In FIG. 7 we can observe that the north and south pins, 326 and 451 experience three different types of loads, stretching A, contracting B and neutral C, represented by the arrows as shown, coming from 3 different directions. The other six pins experience also three loads, but in this case two of those loads are the same type, for example, two neutral and one stretching as at pin 132 or two contracting and one stretching as at pin 214. As said above we can establish many different starting pin positions to determine the initial load of the beam before letting the mechanism turn, but only the particular pin position described in FIG. 6 will produce work.
The initial position of the eight crankpins ( 4 ) will allow the beams ( 5 ) to rotate the shafts ( 3 ) in two different directions, depending on the direction of the initial push. To simplify, we will only describe the rotation where the initial push goes from right to left, with respect to the selected main axle ( 1 ) or from East to West, contrary to the rotation direction of the Earth. As said above one third of a revolution of the pins, corresponds to only one of the three moments of the stroke cycle for the entire mechanism. By describing one moment we also describe the other two moments, since for each moment of the cycle the mechanism has four beams ( 5 ) in stretching or A configuration ( FIG. 11 ), four beams in contracting or B configuration ( FIG. 12 ) and four beams ( 5 ) in neutral or C configuration ( FIG. 13 ). FIG. 10 a shows altogether the three groups of four different configuration beams ( 5 ) from FIGS. 11 , 12 and 13 describing the selected initial moment of load for the twelve beams ( 5 ) required for the mechanism to work properly.
After the mechanism rotates one third of a revolution to complete the described first moment of the cycle, each of the beams ( 5 ) change configuration due to the fact that the mechanism enters the second moment of the cycle described in FIG. 10 b . The order of configuration in which the cycle turns is the following: A, B, C, A, B, C. In other words, the initial phi position should be placed in such a way that after stretching (A) comes contracting (B) and after contracting (B) comes neutral (C), neutral is a combination of stretching and contracting. After neutral (C), the cycle finishes only to start all over again with a stretching (A) movement.
If we want to predict the configuration of the next two moments of FIG. 6 , we only need to rotate the figure about the central axle ( 1 ), the North-South axis, by 120 degrees to the East or to the right, from the position of FIG. 14 a , to place the three A beams spanning pins 263-356-645-514 in front view, describing moment # 2 ( FIG. 15 a ) and by rotating another 120 degrees, for a total of 240 degrees, the three B beams spanning pins 632-264-421-145 will position in front view, describing moment # 3 of the cycle ( FIG. 16 a ). The cycle starts all over again in moment # 1 described in FIG. 14 a by a further rotation of 120 degrees so that the three C beams spanning pins 326-132-513-451 are once again at the front. FIGS. 14 b , 15 b and 16 b show the same described moments # 1 , # 2 and # 3 in a top view, with the North Pole or pin 326, in front view. In this view we see the mechanism turning counter clock wise, while we go through moments # 1 , # 2 and # 3 of the cycle.
In the described Figures, B represents a beam contracting, A represents a stretching beam and C represents the end of the contracting reciprocating movement ( 7 ) and the beginning of the stretching reciprocating movement ( 8 ), since C includes both directions of movement we represent this moment as neutral. The key for the mechanism to work is to overcome the loads of the initial part of the C moment, the contracting part ( 7 ), because once the midpoint or neutral position of this moment is reached, the combined loads of the twelve beams will favor rotation. This means that the loads ( 7 ) need to be overcome three times for every revolution of the mechanism, each time in a different section of the mechanism.
To overcome this initial part of the neutral C moment ( 7 ) we need the input of other forces like centripetal and coriolis, that are considered pseudo-forces, but necessary to allow for the mechanism to keep turning. If we place the mechanism in one hemisphere we can also use as input the coriolis force of the Earth's rotation, apart from the coriolis force of the mechanism itself. We need to switch the direction of the initial push if the mechanism is located in the other hemisphere. As well as a Foucault pendulum turns with the help of the Earth's rotation we can use this force as an input to keep the mechanism running.
If engineering determines that the Earth's rotation force is not needed to give additional impulse to the mechanism, it might turn out that the gravitational pull of the Earth affects the reactions and balance of the stretching and contracting beams. If this is the case there is a possibility that this mechanism may only work outside the influence of the gravitational pull of the Earth despite this possibility, the mechanism has terrestrial utility as a teaching aid. See FIG. 17 . The model can be driven by an input energy rather than producing energy itself. For example, beams ( 5 ) may be fabricated from a material which adopts a decreased radius curvature (B) under the influence of current flow yet returns to an increased radius curvature (A) when current flow ceases. By providing a power source, switching means and electrical connection from the power source to the beams through the switching means, each set of four beams can be alternately switched on and off so as to conform to the ABC sequence previously described thereby causing the mechanism to rotate about the axle ( 1 ). Alternatively, an input stimulus other than electricity may be used, for example heat, magnetic energy, light, radio frequency, or the like may be used, with the beams being fabricated from appropriate materials responsive to such stimuli. Connecting the axle ( 1 ) through the rotational mounts ( 101 ) to a take off means will permit the rotation generated by the mechanism to be applied to produce work. In this way provides a practical tool to describe how an energy flow can find a symmetrical path around a spherical body. The mechanism can also be used to explain in a mechanical movement how a spherical body can find its axis of rotation and explain the functioning of coriolis and centrifugal forces.
According to descriptions provided above, we find in FIG. 10 a the necessary information to determine in a schematic two-dimensional way the starting pin positions and direction for the twelve pins described in FIG. 7 in a three-dimensional way. To further describe the A, B and C moments and corresponding pin positions and directions of rotation, FIG. 10 a should be analyzed along with FIGS. 11 , 12 and 13 . FIG. 11 describes with more detail the upper row of the scheme from FIG. 10 a . Accordingly, FIG. 12 describes the middle row of FIG. 10 a and FIG. 13 describes the lower row of FIG. 10 a . After the mechanism turns the first third of a revolution described in FIG. 10 a , the second moment of the cycle is described in FIG. 10 b , corresponding to the second third of a revolution and FIG. 10 c describes the final moment of the cycle, which corresponds to the last third of a revolution of the mechanism needed to complete a full cycle.
In the preferred embodiment described above, the selected measurements for the key elements of the mechanism are: the beam “beamlength=d+2(d−a)”; the offset radius of the pin “offsetpinlength=a−b”; the shaft from the center of the octagear to the plane of the offset pin “shaftlength=4d/π”. Nevertheless other measurements work as well, comprehended within the scope of this application.
All variables depend on the selected size “d” of the apparatus:
d
=
a
2
4
(
a
-
b
)
=
8
2
a
-
(
2
a
+
4
b
+
4
h
+
2
a
2
)
h
=
3
2
c
=
3
2
3
(
d
-
a
)
=
3
2
(
d
-
a
)
Where “a”, “b”, “c” and “h” are selected proportions of the selected size “d” of the apparatus. In simple terms these calculations resume in an “offsetpinlength” of about 1% of the “beamlength”.
In an alternative embodiment shown in FIG. 18 , the mechanism employs the principles of a vibrating string to produce rotation. In this embodiment the beams ( 5 ) vibrate between an outer fully contracted position, as seen in FIG. 19 a , and an inner fully contracted position, FIG. 22 a , returning to the outer fully contracted position. In this process, the beams ( 5 ) pass through an outer stretching position, FIG. 20 a , and an inner stretching position, FIG. 23 a , as well as outer and inner contracting positions, FIGS. 21 a and 24 a respectively, resulting in a six stroke cycle producing two revolutions per cycle.
To accommodate this string vibration of the beams ( 5 ), the mechanism requires a slight modification to the connections of the beams ( 5 ) with the shafts ( 3 ) and axle ( 1 ). Instead of the leverarms or plates ( 21 ) and crankpins ( 4 ) at the ends, shafts ( 3 ) and axle ( 1 ) are provided with bent cranks ( 25 ) around which the rings or bushings ( 23 ) to which the ends of the beams ( 5 ) attach are disposed. As in the first embodiment, the rings ( 23 ) have an appropriate bearing surface with the cranks ( 25 ) to provide low or no friction rotation of the rings ( 23 ) relative to the cranks ( 25 ) upon alternating contracting and stretching of the beams ( 5 ) In addition, the beams ( 5 ) attach to the rings ( 23 ) by suitable universal-type joints.
As shown in FIG. 18 , the location of the cranks ( 25 ) is inward from the ends of shafts ( 3 ) and axle ( 1 ) resulting in the beams ( 5 ) being inside the cube frame ( 6 ). In this manner, the ends of shafts ( 3 ) terminate at bearings ( 24 ) at six of the corners of the cube ( 6 ). Only the axle ( 1 ) passes through its associated cube bearings ( 24 ) to the rotational mounts ( 101 ) on frame ( 100 ).
If needed for additional structural rigidity of the mechanism, a second smaller cube frame ( 26 ) may be provided around the octagear ( 2 ), the corners of the smaller cube frame ( 26 ) being low or no friction sleeve bearings or bushings ( 27 ) through which shafts ( 3 ) and axle ( 1 ) pass. Although only shown in connection with the second embodiment of FIG. 18 , this second smaller cube frame ( 26 ) may also be applied to the mechanism of the first embodiment of FIG. 6 . As a further alternative, the bevel gears ( 20 ) may be supported by an internal frame or sphere, as indicated previously, so as to be rotatable thereon.
As noted previously with the beams ( 5 ) attached at the ends of shafts ( 3 ), the mechanism of the first embodiment requires that beams ( 5 ) maintain a minimal radius of curvature in the stretched position. If the beams ( 5 ) of the first embodiment adopt a straight line in the stretched position, the mechanism will lock.
In contrast, the vibrating beams ( 5 ) of the second embodiment pass through a straight line position from the outer contracted position to the inner contracted position and return. This results in the six stroke cycle shown in FIGS. 19-24 . Following the convention established previously and considering the fully contracted positions of FIGS. 19 a and 22 a equivalent to the neutral position of the beams ( 5 ) of the first embodiment, the sequence of operation illustrated in FIGS. 19-24 is fully outer contracted or neutral, C, outer stretching, A, inner contracting, B, fully inner contracted, C, inner stretching, A, and outer contracting, B. Thus, the order of configuration for the beams ( 5 ) of the second embodiment becomes C, A, B, C, A, B, producing rotation moments as shown in FIGS. 19 b - 24 b . FIGS. 21 b , 22 b and 23 b represent inner contracting, neutral and stretching moments and are designated by the dot at the end of the arrows signifying the direction of rotation. Each moment or stroke produces 120 degrees of rotation conveyed to axle ( 1 ) through octagear ( 2 ). Thus, the first three strokes, C, A, B, from fully outer contracted to inner contracting as shown in FIGS. 19 a - 21 a , results in one complete revolution of the mechanism. Similarly, the return strokes, C, A, B, from fully inner contracted to outer contracting as shown in FIGS. 22 a - 24 a , produce a second complete revolution such that one complete cycle of six strokes produces two complete revolutions of the mechanism. The balance of this cycle between inner and outer stretching and contracting is important to provide the extra push needed to create output.
Although slightly different in structure, the overall operation and rotational characteristics of the mechanisms of the first and second embodiments are substantially identical.
In FIGS. 25 a, b and c the numbered triangles correspond to the crank mechanisms, i.e., crankpin ( 4 ) or crank ( 25 ) positions relative to the faces of the cube ( 6 ) as previously explained and the lines between triangles describe the corresponding beams. The arrows show the direction in which the crank mechanism is turning. These arrows have to turn around the triangles six times, or two revolutions to complete 1 cycle. FIG. 25 a shows a set of three particular beams ( 5 ) contracting, B, and FIG. 25 c shows another set of three particular beams ( 5 ) stretching, A. In FIG. 25 b a third set of three bars in contracted or neutral, C, position, with the particular characteristic that all the crank mechanisms represented by arrows are moving in the same direction. This “opening” or “clear way” that appears every time the aligned group is in the neutral or C moment, promotes frictionless rotation to that sector of the mechanism at that particular point in time. At every one of the six moments of the cycle, there is a contracted or neutral C group of beams ( 5 ) aligned in a sector of the mechanism taking advantage of the described alignment.
Moreover, the mechanism shows at every moment of the cycle three groups of three aligned bars, each group extending in zigzag from pole to pole, occupying an opposed sector of the mechanism, each sector going through an opposed stretching/contracting moment of the cycle, which in turn adds symmetry, balance and combined efforts between groups of beams to promote the cycle. Thereby we know that the stages or strokes of a cycle always go in the order of contracting/contracted/stretching (B/C/A), opposed to the other option B/A/C. This particular order comes from the restrictions that we set on the way the crank mechanisms move, via the initial position of the crank mechanisms around the mechanism. Also each group of aligned beams ( 5 ) accommodate in three opposed directions from the poles down, in the same particular order: B/C/A, coinciding with the direction of the rotation of the mechanism. As in FIGS. 10 a, b and c , FIGS. 30 a - d , 31 a - d and 32 a - d show the three groups of four configuration beams ( 5 ) of the second embodiment describing the selected initial moment of load for the twelve beams ( 5 ) required for proper operation of the mechanism. Because the beams ( 5 ) of the second embodiment exhibit both inward and outward motion, the point of inward motion is indicated by a dot at the end of the arrows signifying the direction of rotation for the particular shaft.
This symmetry makes it simple to predict the next stage of any group of three aligned beams. As an example, by looking at the position of the arrows of FIG. 25 c one can easily deduce that they correspond to the next cycle of the arrows of FIG. 25 b . In the same way, FIG. 25 a . corresponds to the next moment of FIG. 25 c . Notice that if we were describing three consecutive moments of a group of aligned beams ( 5 ), FIGS. 25 a, b and c would need to show the same numbers inside the triangles in each Figure. As they are, FIGS. 25 a, b and c describe one single stroke moment in time, the initial one, of the nine beams ( 5 ) that align in three groups distributed in opposed sectors of the mechanism. As a general rule in predicting the next moment of a particular group of aligned beams ( 5 ), we know that the future stage of an aligned group is the present stage of the aligned group to the left or west (this is to the direction of the turn, because in our case the rotation is East-to-West). The alternate option would be that they align in order: B/A/C.
The importance of this conclusion is that by these aligned groups accommodating in the described order the balance of the beams in the second embodiment favors rotation because although the relation between aligned groups is one of increasing contraction in counter direction to the rotation, since at stroke # 1 the aligned group of beams in the right of the fully contracted group of beams shows increasing contraction in stroke # 2 , that contraction is of the inner type, favoring the balance to the left, where the single beam in stroke # 2 is showing outward increasing contraction also favoring the balance to the left.
The cycle of the mechanism continues to show its symmetry when the three single equatorial beams ( 5 ) placed between the three groups of aligned beams ( 5 ) exhibit stroke moments opposed from the moments of the groups. For example, between a pole-to-pole B aligned group on the East of the mechanism and a similar C aligned group on West side, we find a single equatorial beam ( 5 ) exhibiting a stretching moment (A). FIGS. 26 a, b and c show the relationship between aligned groups and single beams ( 5 ). Note in the figures, that six beams ( 5 ) form the equatorial sector of the mechanism, the left and right triangle have the same number since six beams ( 5 ) form a circle (for this reason these triangles are partially represented in dotted lines. FIG. 26 a describes a first moment, from right to left: contracted (C)/stretching (A)/contracting (B)/contracted (C)/stretching (A)/contracting (B)/. FIG. 26 b describes a second moment, from left to right: (A)/(B)/(C)/(A)/(B)/(C). FIG. 26 c describes a third moment: (B)/(C)/(A)/(B)/(C)/(A). Note in FIGS. 26 a, b and c by the number inside the triangles that three of the beams ( 5 ) correspond with beams ( 5 ) in FIGS. 25 a, b and c , those beams ( 5 ) being part of the aligned group of beams ( 5 ), the rest of the beams ( 5 ) being the single beams ( 5 ). In conclusion we can affirm that the symmetry of the mechanism runs aligned along the latitude and runs alternated along the longitude of the mechanism.
This symmetry results in a synchronized cooperation of the beams ( 5 ) that in a top view exhibit at every one of the six moments of the cycle half a sphere in inside position and the other half in outside position as shown in FIGS. 27 a - f . These figures follow the bending moments of beams ( 5 ) through a complete six stroke cycle of the mechanism viewed from a polar position and progressing in a clockwise or East-to-West direction.
This symmetry results in a wave-like motion around the mechanism which causes the center of mass to similarly move in a wave around the mechanism. It is believed that this wave-like oscillation of the center of mass adds to the initial input of force into the mechanism and, thereby, promotes continued rotation beyond that point where friction would ordinarily overcome momentum and bring the operation to a halt. Theoretically, if all friction could be removed, the oscillation of the center of mass around the mechanism could provide sufficient input to maintain operation of the mechanism indefinitely. However, such indefinite operation is neither contemplated nor sought by the present application.
The movement of the center of mass serves as an additional force input to that initially applied to start the mechanism and to overcome the load of the beams ( 5 ) and permit the mechanism to progress through the strokes of the cycle of operation.
Assigning one unit of pressure to every degree that the mechanism turns, helps in visualizing that due to the symmetry of the initial selected position of the beams, the cycle will show peaks and valleys when combining the loads of the twelve beams.
A fully contracted (C) beam carries more load than a straight one. Assigning 180 units of load to the (C) beam position, when the crankpins ( 4 ) or cranks ( 25 ) holding a (C) beam turn 180 degrees or half a revolution, the beam adopts a straight position (S) that carries no load so zero units of load are assigned for the (S) position. The graphs of FIGS. 28 and 29 represent the load forces on the beams during a six stroke cycle of the mechanism and the dotted line represents the zero load or (S) position. The y-axis represents load quantity between zero and 180 units of load and the x-axis represents time, divided in 6 strokes (6 strokes=2 revolutions=1 cycle). Between each stroke we find intermediate 0.5 positions, from now on (½x). We name full positions as (x).
Adding the combined loads of the beams at different points in time we can determine that the load rises at the (x) positions and drops at the (½x) positions. For example, in FIG. 28 , stroke 1 has a combined load of 60+60+180=300 and stroke 1 . 5 has a combined load of 120+120+0=240. Each cycle goes 3 times through a peak and 3 times through a valley.
Assuming that the beams have a perfect elasticity we can conclude that the mechanism will eventually stop due to friction and other forces at a (½x) position. Now when the mechanism is in an (x) position load needs to be relieved towards the (½x) position. But when it reaches (½x) it will continue its rotation due to the impulse. In a frictionless world that impulse would bring the mechanism back to the next (x) position in another section of the apparatus.
Following the same above example: FIG. 28 represents in A the cycle and load moment of the three aligned fully contracted or neutral (A) beams, B represents the three aligned contracting or (B) beams and C represents the three aligned stretching or (C) beams. FIG. 29 represents in A the cycle and load moment of a single equatorial stretching or (A) beam, B represents a single equatorial contracting or (B) beam and C represents a single equatorial contracted or neutral (C) beam. When we add the loads in FIG. 28 three times (3×(180+60+60)=900) and the loads in FIG. 29 one time (1×(180+60+60)=300), our example results in a total load of 1200 units for (x) positions and 960 (4×(0+120+120)=960) units for (½x) positions. So the total (x) load less the total (½x) load equals 1200−960=240 units.
The mechanism needs to overcome a load of 240 (20% of total maximum load) units to be able to reach the next stroke. Impulse itself will help a lot, engineering can produce acceleration at the straight-line position (S), but we can also count on the center of mass movement as an additional force. If we imagine the mechanism as a spinning figure skater, when she pulls her hands close to the rotation axis the rotation rate increases, in turn when she straightens her arms out the rate reduces. FIG. 27 a - f shows in a top view the position of the beams at each stroke. FIG. 27 a describes stroke 1 and FIG. 27 f describes stroke 6 . The arrows at each figure show the direction of rotation and the section of the hexagon where the center of mass locates at each stroke. Following the example of the skater, for every stroke of the mechanism six beams in one section of the apparatus are in the outer phase of fully contracted, contracting or stretching, equivalent to the skater's arms moving outward, and the other six beams are in the inner phase of fully contracted, contracting or stretching and, like the faster spinning skater, have their mass closer to the rotational axis on the opposite section of the apparatus.
The position and not the force of the vibrating beams is what results in this oscillation of the center of mass relative to the rotational axis in the right time for each stroke thereby adding force to overcome the 240 units of load to reach the next stroke moment.
It is important to note in FIG. 27 that the sequence ( 27 a - f ) describes a top view of a mechanism that is not rotating. The six three digit numbers, describing the pin location at the vertices of the apparent hexagon correspond to the visible corners of cube frame ( 6 ) and are fixed in space throughout the sequence (a-f). The three digit configuration on the numbers varies but the pins are always the same. For example in FIG. 27 a the bottom right number is 132, in FIG. 27 b that same location shows 321 and FIG. 27 c shows 213. As described before the lever arm located in the corner of the die where 1, 2 and 3 meet, can be described as 132, 321 or 213 because the numbers tells us about the shaft location and the order tells us about the direction and pin position. The six strokes described in the sequence (a-f) show similar number configuration for the first (a-c) and second (d-f) revolutions, only that the beam positions are different.
If we run in a video a couple of cycles ( 27 a - f ) one after the other, it appears as if the mechanism is rotating clockwise, but we know from the above description that at this moment the mechanism is fixed in space (only the central axle ( 1 ) is rotating counterclockwise). The illusion of rotation means that the individual masses of each beam are not only doing work by rotating the lever arms, but more important, each individual beam is also working in coordination with the rest of the beams pushing the center of mass around the central axle ( 1 ) once for every cycle. The result is that the twelve beams adopt the previous position 60 degrees to the right. The beams are not adopting a lean because of the centrifugal force of the rotation, the amazing result is that the beams are predicting or suggesting a rotation. When the sequence is seen from other points of view the motion across the mechanism appears to be random. But when viewed from above the north pole, it appears like the mechanism changes its form—stroke by stroke—to create an invisible lever arm that is offset relative to the axis of rotation that pushes the whole body of the mechanism clockwise. Such behavior is not expected.
What this means is that if we invert the forces and we now fix the rotating axle to the ground and allow free rotation of the mechanism, the individual beams will do their part in stretching and contracting resulting in a synergy which creates an orderly movement of the center of mass across the mechanism and gives the mechanism an “additional” extra push towards rotation, at this moment is when the pseudo forces appear. We are in front of a very special case: a self-organization that induces unexpected energy to the cycle. This sudden coherence in what should only be random fluctuation of the beams teachings of this mechanism. We believe this coherence is driven by gravity, created by the impossibility of the octacore to penetrate its own core.
The idea is to bring the mechanism so close to equilibrium, that a minor added impulse, such as the inherent motion of the mechanism or the coriolis or centrifugal force from other bodies acting on it, like the rotation of the Earth, will add the needed input to overcome each stroke and propel the mechanism to the next moment in the cycle.
Although, in theory, coriolis and centrifugal forces will have an effect on any size mechanism, in practical terms the apparatus would have to be of a large size to conclusively demonstrate such effect. However, in smaller size models we can use the mechanism as teaching aid to show an example of a mechanism that comes very close to equilibrium, to demonstrate the theory that pseudo forces like coriolis or centrifugal can have on spinning objects.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, that all such modifications and changes are within the true spirit and scope of the invention as recited in the following claims.
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An apparatus for teaching concepts concerning equilibrium, symmetry of energy flow and spherical motion including a centrally located octagear with eight engaging bevel gears, each having a central axis at a 70° angle relative to its adjacent gears. Each gear has a central shaft extending outwardly from the octagear, with the shafts having identical lengths. Reciprocating motion delivered to a crank mechanism is translated into rotary motion of the shaft, this rotary motion being transmitted to the gear at the end of the shaft. Connecting the crank mechanisms of each shaft are a plurality of beams with each beam spanning the space between two crank mechanisms. Each beam is capable of flexing between a first curved position and a second curved position resulting in a change in the span length of the beam and generating reciprocatory motion transmitted to the crank mechanisms. A cube-shaped frame is also provided.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to high strength, high toughness steel alloys, and in particular, to such an alloy that can be tempered at a significantly higher temperature without significant loss of tensile strength. The invention also relates to a high strength, high toughness, tempered steel article.
Description of the Related Art
Age-hardenable martensitic steels that provide a combination of very high strength and fracture toughness are known. Among the known steels are those described in U.S. Pat. No. 4,076,525 and U.S. Pat. No. 5,087,415. The former is known as AF1410 alloy and the latter is sold under the registered trademark AERMET. The combination of very high strength and toughness provided by those alloys is a result of their compositions which include significant amounts of nickel, cobalt, and molybdenum, elements that are typically among the most expensive alloying elements available. Consequently, those steels are sold at a significant premium compared to other alloys that do not contain such elements.
More recently, a steel alloy has been developed that provides a combination of high strength and high toughness without the need for alloying additions such as cobalt and molybdenum. One such steel is described in U.S. Pat. No. 7,067,019. The steel described in that patent is an air hardening CuNiCr steel that excludes cobalt and molybdenum. In testing, the alloy described in the '019 patent has been shown to provide a tensile strength of about 280 ksi together with a fracture toughness of about 90 ksi √in. The alloy is hardened and tempered to achieve that combination of strength and toughness. The tempering temperature is limited to not more than about 400° F. in order to avoid softening of the alloy and a corresponding loss of strength.
The alloy described in the '019 patent is not a stainless steel and therefore, it must be plated to resist corrosion. Material specifications for aerospace applications of the alloy require that the alloy be heated at 375° F. for at least 23 hours after being plated in order to remove hydrogen adsorbed during the plating process. Hydrogen must be removed because it leads to embrittlement of the alloy and adversely affects the toughness provided by the alloy. Because this alloy is tempered at 400° F., the 23 hour 375° F. post-plating heat treatment results in over-tempering of parts made from the alloy such that a tensile strength of at least 280 ksi cannot be provided. It would be desirable to have a CuNiCr alloy that can be hardened and tempered to provide a tensile strength of at least 280 ksi and a fracture toughness of about 90 ksi √in, and maintain that combination of strength and toughness when heated at about 375° F. for at least 23 hours, subsequent to being hardened and tempered.
SUMMARY OF THE INVENTION
The disadvantages of the known alloys as described above are resolved to a large degree by an alloy according to the present invention. In accordance with one aspect of the present invention, there is provided a high strength, high toughness steel alloy that has the following broad and preferred weight percent compositions.
Element Broad Preferred A Preferred B Preferred C C 0.30-0.55 0.37-0.50 0.30-0.40 0.40-0.47 Mn 0.6-1.3 0.7-0.9 0.8-1.3 0.8-1.3 Si 0.9-2.5 1.3-2.1 1.5-2.5 1.5-2.5 Cr 0.75-2.5 1.2-1.5 1.5-2.5 1.5-2.5 Ni 3.0-7.0 3.7-4.5 3.0-4.5 4.0-5.0 Mo + ½ W 0.4-1.3 0.5-1.1 0.7-0.9 0.7-0.9 Cu 0.5-0.9 0.5-0.6 0.70-0.90 0.70-0.90 Co 0.01 max. 0.01 max. 0.01 max. 0.01 max. V + ( 5/9) × Nb 0.10-1.0 0.2-1.0 0.10-0.25 0.10-0.25 Ti 0.001 max. 0.001 max. 0.005 max. 0.005 max. Al 0.015 max. 0.015 max. Fe Balance Balance Balance Balance
Included in the balance are the usual impurities found in commercial grades of steel alloys produced for similar use and properties. Among said impurities phosphorus is preferably restricted to not more than about 0.01% and sulfur is preferably restricted to not more than about 0.001%. Within the foregoing weight percent ranges, silicon, copper, and vanadium are balanced such that
2≦(% Si+% Cu)/(% V+(5/9)×% Nb)≦34.
The foregoing tabulation is provided as a convenient summary and is not intended to restrict the lower and upper values of the ranges of the individual elements for use in combination with each other, or to restrict the ranges of the elements for use solely in combination with each other. Thus, one or more of the ranges can be used with one or more of the other ranges for the remaining elements. In addition, a minimum or maximum for an element of a broad or preferred composition can be used with the minimum or maximum for the same element in another preferred or intermediate composition. Moreover, the alloy according to the present invention may comprise, consist essentially of, or consist of the constituent elements described above and throughout this application. Here and throughout this specification the term “percent” or the symbol “%” means percent by weight or mass percent, unless otherwise specified.
In accordance with another aspect of the present invention, there is provided a hardened and tempered steel alloy article that has very high strength and fracture toughness. The article is formed from an alloy having the broad or preferred weight percent composition set forth above. The alloy article according to this aspect of the invention is further characterized by being tempered at a temperature of about 500° F. to 600° F.
DETAILED DESCRIPTION
The alloy according to the present invention contains at least about 0.30% and preferably at least about 0.32% carbon. Carbon contributes to the high strength and hardness capability provided by the alloy. When higher strength and hardness are desired, the alloy preferably contains at least about 0.40% carbon (e.g., Preferred C). Carbon is also beneficial to the temper resistance of this alloy. Too much carbon adversely affects the toughness provided by the alloy. Therefore, carbon is restricted to not more than about 0.55%, better yet to not more than about 0.50%, and preferably to not more than about 0.47%. The inventor has found that when the alloy contains as little as 0.30% carbon, the upper limit for carbon can be restricted to not more than about 0.40% and the alloy can be balanced with respect to its constituents (e.g., Preferred B) to provide a tensile strength of at least 290 ksi.
At least about 0.6%, better yet at least about 0.7%, and preferably at least about 0.8% manganese is present in this alloy primarily to deoxidize the alloy. It has been found that manganese also benefits the high strength provided by the alloy. Thus, when higher strength is desired, the alloy contains at least about 1.0% manganese. If too much manganese is present, then an undesirable amount of retained austenite may result during hardening and quenching such that the high strength provided by the alloy is adversely affected. Therefore, the alloy may contain up to about 1.3% manganese. Otherwise, the alloy contains not more than about 1.2% or not more than about 0.9% manganese.
Silicon benefits the hardenability and temper resistance of this alloy. Therefore, the alloy contains at least about 0.9% silicon and preferably, at least about 1.3% silicon. At least about 1.5% and preferably at least about 1.9% silicon is present in the alloy when higher hardness and strength are needed. Too much silicon adversely affects the hardness, strength, and ductility of the alloy. In order to avoid such adverse effects silicon is restricted to not more than about 2.5% and preferably to not more than about 2.2% or 2.1% in this alloy.
The alloy contains at least about 0.75% chromium because chromium contributes to the good hardenability, high strength, and temper resistance provided by the alloy. Preferably, the alloy contains at least about 1.0%, and better yet at least about 1.2% chromium. Higher strength can be provided when the alloy contains at least about 1.5% and preferably at least about 1.7% chromium. More than about 2.5% chromium in the alloy adversely affects the impact toughness and ductility provided by the alloy. In the high strength embodiments of this alloy chromium is preferably restricted to not more than about 1.9%. Otherwise, chromium is restricted to not more than about 1.5% in this alloy and better yet to not more than about 1.35%.
Nickel is beneficial to the good toughness provided by the alloy according to this invention. Therefore, the alloy contains at least about 3.0% nickel and preferably at least about 3.1% nickel. A preferred embodiment of the alloy (e.g., Preferred A) contains at least about 3.7% nickel. When the alloy is balanced to provide higher strength, it preferably contains at least about 4.0% and better yet at least about 4.6% nickel. The benefit provided by larger amounts of nickel adversely affects the cost of the alloy without providing a significant advantage. In order to limit the upside cost of the alloy, the amount of nickel is restricted to not more than about 7%. Thus, for the highest strength embodiment of the alloy (e.g., Preferred C), up to about 5.0% nickel, preferably up to about 4.9% nickel, can be present. In lower strength embodiments (e.g., Preferred A and Preferred B) the alloy contains not more than about 4.5% nickel.
Molybdenum is a carbide former that is beneficial to the temper resistance provided by this alloy. The presence of molybdenum boosts the tempering temperature of the alloy such that a secondary hardening effect is achieved at about 500° F. Molybdenum also contributes to the strength and fracture toughness provided by the alloy. The benefits provided by molybdenum are realized when the alloy contains at least about 0.4% molybdenum and preferably at least about 0.5% molybdenum. For higher strength, the alloy contains at least about 0.7% molybdenum. Like nickel, molybdenum does not provide an increasing advantage in properties relative to the significant cost increase of adding larger amounts of molybdenum. For that reason, the alloy contains up to about 1.3% molybdenum, better yet not more than about 1.1% molybdenum, preferably not more than about 0.9% molybdenum in the higher strength forms of the alloy (Preferred B and Preferred C). Tungsten may be substituted for some or all of the molybdenum in this alloy. When present, tungsten is substituted for molybdenum on a 2:1 basis.
This alloy preferably contains at least about 0.5% copper which contributes to the hardenability and impact toughness of the alloy. When higher strength is desired, the alloy contains at least about 0.7% copper. Too much copper can result in precipitation of an undesirable amount of free copper in the alloy matrix and adversely affect the fracture toughness of the alloy. Therefore, not more than about 0.9% and preferably not more than about 0.85% copper is present in this alloy. Copper can be limited to about 0.6% max. when very high strength is not needed.
Vanadium contributes to the high strength and good hardenability provided by this alloy. Vanadium is also a carbide former and promotes the formation of carbides that help provide grain refinement in the alloy and that benefit the temper resistance and secondary hardening of the alloy. For those reasons, the alloy preferably contains at least about 0.10% and preferably at least about 0.14% vanadium. Too much vanadium adversely affects the strength of the alloy because of the formation of larger amounts of carbides in the alloy which depletes carbon from the alloy matrix material. Accordingly, the alloy may contain up to about 1.0% vanadium, but preferably contains not more than about 0.35% vanadium. In the higher strength embodiments of the alloy (Preferred B and Preferred C), vanadium is restricted to not more than about 0.25% and preferably to not more than about 0.22%. Niobium can be substituted for some or all of the vanadium in this alloy because like vanadium, niobium combines with carbon to form M 4 C 3 carbides that benefit the temper resistance and hardenability of the alloy. When present, niobium is substituted for vanadium on 1.8:1 basis.
This alloy may also contain a small amount of calcium up to about 0.005% retained from additions during melting of the alloy to help remove sulfur and thereby benefit the fracture toughness provided by the alloy.
Silicon, copper, vanadium, and when present, niobium are preferably balanced within their above-described weight percent ranges to benefit the novel combination of strength and toughness that characterize this alloy. More specifically, the ratio (% Si+% Cu)/(% V+(5/9)×% Nb) is about 2 to 34. The ratio is preferably about 6-12 for strength levels below about 290 ksi. For strength levels of 290 ksi and above, the alloy is balanced such that the ratio is about 14.5 up to about 34. It is believed that when the amounts of silicon, copper, and vanadium present in the alloy are balanced in accordance with the ratio, the grain boundaries of the alloy are strengthened by preventing brittle phases and tramp elements from forming on the grain boundaries.
The balance of the alloy is essentially iron and the usual impurities found in commercial grades of similar alloys and steels. In this regard, the alloy preferably contains not more than about 0.01%, better yet, not more than about 0.005% phosphorus and not more than about 0.001%, better yet not more than about 0.0005% sulfur. The alloy preferably contains not more than about 0.01% cobalt. Titanium may be present at a residual level of up to about 0.01% from deoxidation additions during melting and is preferably restricted to not more than about 0.005%. Up to about 0.015% aluminum may also be present in the alloy from deoxidation additions during melting.
The alloys according to preferred compositions B and C is balanced to provide very high strength and toughness in the hardened and tempered condition. In this regard, the Preferred B composition is balanced to provide a tensile strength of at least about 290 ksi in combination with good toughness as indicated by a K Ic fracture toughness of at least about 70 √in. In addition, the Preferred C composition is balanced to provide a tensile strength of at least about 310 ksi in combination with a K Ic fracture toughness of at least about 50 √in for applications that require higher strength and good toughness.
No special melting techniques are needed to make the alloy according to this invention. The alloy is preferably vacuum induction melted (VIM) and, when desired as for critical applications, refined using vacuum arc remelting (VAR). The alloy can also be arc melted in air (ARC) if desired. After ARC melting, the alloy may be refined by electroslag remelting (ESR) or VAR.
The alloy of this invention is preferably hot worked from a temperature of up to about 2100° F., preferably at about 1800° F., to form various intermediate product forms such as billets and bars. The alloy is preferably heat treated by austenitizing at about 1585° F. to about 1735° F. for about 1-2 hours. The alloy is then air cooled or oil quenched from the austenitizing temperature. When desired, the alloy can be vacuum heat treated and gas quenched. The alloy is preferably deep chilled to either −100° F. or −320° F. for about 1-8 hours and then warmed in air. The alloy is preferably tempered at about 500° F. for about 2-3 hours and then air cooled. The alloy may be tempered at up to 600° F. when an optimum combination of strength and toughness is not required.
The alloy of the present invention is useful in a wide range of applications. The very high strength and good fracture toughness of the alloy makes it useful for machine tool components and also in structural components for aircraft, including landing gear. The alloy of this invention is also useful for automotive components including, but not limited to, structural members, drive shafts, springs, and crankshafts. It is believed that the alloy also has utility in armor plate, sheet, and bars.
Working Examples
Two 400 lb. heats having the weight percent compositions shown in Table 1 below were prepared for evaluation as follows. Both heats were vacuum induction melted and then cast as
TABLE 1 Element Heat 1 Heat 2 C 0.35 0.41 Mn 1.17 1.18 Si 2.00 2.02 P 0.008 0.007 S <0.0005 0.0006 Cr 1.74 1.74 Ni 3.24 4.75 Mo 0.77 0.76 Cu 0.79 0.79 Co <0.01 Ti 0.006 0.006 Al 0.007 0.008 N 0.0032 0.0036 O 0.0010 <0.0010 V 0.19 0.19 Fe Bal. Bal.
7.5 inch square ingots. The ingots were heated at 2300° F. for a time sufficient to homogenize the alloys. The ingots were then hot worked from a temperature of 1800° F. to 3½ inch×5 inch bars. The bars were then reheated to 1800° F. and a portion of each bar was further hot worked to a cross section of 1½ inches×4⅝ inches. The hot working was carried out in steps with reheating of the intermediate forms as needed. After forging, the bars were allowed to cool to room temperature in air. The cooled bars were each then cut into two pieces at the junction between the two section sizes. The bar pieces were annealed at 1250° F. for 8 hours and then cooled in air.
Standard tensile, Charpy V-notch, and fracture toughness, and hardness test specimens were prepared from the bar pieces with both longitudinal and transverse orientations. The test specimens were heat treated as follows for testing. The specimens of Heat 1 were austenitized in a vacuum furnace at 1685° F. for 1.5 hours and then gas quenched. The as-quenched specimens were deep chilled at −100° F. for 8 hours and then warmed to room temperature in air. Finally, the specimens were tempered at 500° F. for 2 hours and then cooled in air from the tempering temperature. The specimens of Heat 2 were austenitized in a vacuum furnace at 1735° F. for 2 hours and then gas quenched. The as-quenched specimens were deep chilled at −100° F. for 8 hours and then warmed to room temperature in air. Finally, the specimens were tempered at 500° F. for 2 hours and then cooled in air from the tempering temperature.
The results of room temperature tensile, Charpy V-notch, and K Ic fracture toughness testing are shown in Tables 2A and 2B below including the 0.2% offset yield strength (Y.S) and ultimate tensile strength (U.T.S.) in ksi, the percent elongation (% El.) and percent reduction in area (% R.A.), the Charpy V-notch impact strength (CVN) in ft-lbs, the rising step load K Ic fracture toughness in ksi√in, and Rockwell C-scale hardness (HRC). The rising step load fracture toughness test was conducted in accordance with ASTM Standard Test Procedures E399, E812, and E1290. Table 2A shows the results for Heat 1 and Table 2B shows the results for Heat 2.
TABLE 2A
Orien-
%
tation
Sample
Y.S.
U.T.S.
% El.
R.A.
CVN
K Ic
HRC
Longi-
1
235.8
297.2
11.0
44.9
23.1
73.6
tudinal
2
235.7
296.8
12.7
50.7
22.0
74.8
Average
235.7
297.0
11.9
47.8
22.6
74.2
55.1
Transverse
1
*
*
*
*
22.3
75.0
2
233.8
296.5
11.1
40.8
21.6
73.3
Average
233.8
296.5
11.1
40.8
22.0
74.2
55.2
* = Not Included in Averages - Cause of low properties not known.
TABLE 2B
Orien-
%
tation
Sample
Y.S.
U.T.S.
% El.
R.A.
CVN
K Ic
HRC
Longi-
1A
244.2
312.7
10.9
44.1
19.2
56.8
tudinal
2A
244.5
312.6
11.9
48.8
16.8
55.7
56.3
Longi-
1B
246.9
313.1
10.7
44.1
16.8
57.5
tudinal
2B
245.0
312.1
11.6
50.4
17.9
59.3
56.2
Average
245.1
312.6
11.3
46.9
17.7
57.3
56.3
Transverse
1A
243.9
311.7
10.8
42.2
14.1
55.2
2A
**
**
**
**
14.3
57.6
56.0
Transverse
1B
246.7
312.2
10.6
41.9
15.4
56.4
2B
246.5
312.2
10.9
43.4
15.0
56.9
56.2
Average
245.7
312.1
10.8
42.5
14.7
56.5
56.1
** = Tensile specimen was cracked
The terms and expressions which are employed herein are used as terms of description and not of limitation. There is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof. It is recognized that various modifications are possible within the invention described and claimed herein.
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A high strength, high toughness steel alloy is disclosed. The alloy has the following weight percent composition.
Element C 0.30-0.47 Mn 0.8-1.3 Si 1.5-2.5 Cr 1.5-2.5 Ni 3.0-5.0 Mo + ½ W 0.7-0.9 Cu 0.70-0.90 Co 0.01 max. V + ( 5/9) × Nb 0.10-0.25 Ti 0.005 max. Al 0.015 max. Fe Balance
Included in the balance are the usual impurities found in commercial grades of steel alloys produced for similar use and properties including not more than about 0.01% phosphorus and not more than about 0.001% sulfur. Also disclosed is a hardened and tempered article that has very high strength and fracture toughness. The article is formed from the alloy having the broad weight percent composition set forth above. The alloy article according to this aspect of the invention is further characterized by being tempered at a temperature of about 500° F. to 600° F.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional U.S. Patent Application Ser. No. 60/215,147, filed Jun. 30, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
N/A
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to storm shutters for protecting homes, buildings and other structures from wind and storm related damage, and more particularly to a light transmitting storm shutter assembly that provides sufficient resistance to hurricane force winds and impact from windborne debris while allowing light transmittance into the protected structure.
2. Description of the Background Art
The United States has experienced 44 weather-related disasters in the past 20 years, each of which has caused in excess of $1 billion in damages. Of these 44 disasters, 38 occurred between 1988 and 1998 causing in excess of $170 billion in damage.
Population growth along the coastline of the United States has resulted in an increased risk to life and property from hurricane related damage. There are approximately 36 million permanent residents along the hurricane-prone coastline of the United States, with areas such as Texas, Florida, and the Carolinas, where hurricanes frequently strike, experiencing rapid population growth. In addition, many coastal areas experience substantial but temporary population increases from holiday, weekend, and vacation visitors during hurricane season.
Homes, buildings and other structures, suffer substantial damage when storm generated winds, and particularly windborne debris, penetrate the structures through window and door openings. Hurricane shutters have long been used as barriers to protect window and door openings from the effects of storm generated winds. Equipping homes and other buildings with hurricane protection in the form of storm shutters is one of the most prudent actions one can take to protect life and property.
Accordingly, the background art reveals a number of storm shutters designed for removable installation on homes and buildings. Conventional storm shutters typically consist of corrugated metal panels affixed to the outside of a given structure. For example, U.S. Pat. No. 2,878,536, issued to Becker, discloses a shutter structure having overlapping corrugated panels. U.S. Pat. No. 4,333,271, issued to DePaolo et al., discloses a hurricane panel system for covering windows and doors. The '271 patent discloses a plurality of corrugated metal panels arranged in overlapping relationship to provide a protective structure. U.S. Pat. No. 5,345,716, issued to Caplan, discloses a storm shutter system comprising a combination of individual, interlocking modular elements. U.S. Pat. No. 5,852,903, issued to Astrizky, discloses a hurricane shutter comprising a pair of normally open doors that are swingable to a closed position. U.S. Pat. No. 5,911,660, issued to Watson, discloses a storm panel comprising a plurality of interlocking tiles interlocked together by a plurality of dovetail joints.
A significant disadvantage with conventional storm shutter panels is that installation of the panels over all of the window openings prevents light from entering the structure. Accordingly, if power is lost, as often happens during severe storms, the occupants of the structure find themselves in total darkness. Thus, a number of references disclosed in the background art reveal attempts to provide storm shutters that provide sufficient impact resistance while allowing light to enter to building.
For example, U.S. Pat. No. 5,918,430, issued to Rowland, discloses a removable storm shield comprising convex panels. U.S. Pat. No. 5,996,292, issued to Hill et al., discloses a perforated shutter system wherein at least one panel is formed of corrugations. U.S. Pat. No. 3,358,408, issued to Cooper et al., discloses an insulated light transmitting panel construction having corrugations in the side edges thereof. U.S. Pat. No. 4,685,261, issued to Seaquist, discloses a removable translucent storm shutter consisting of a ½″ thick polycarbonate sheet in an aluminum channel frame. U.S. Pat. No. 5,595,233, issued to Gower, discloses hurricane shutters formed of transparent, double-skinned panels that are strengthened by rods extending through the end channels. The panels are mounted side-by-side to cover the expanse of a window or door being protected. U.S. Pat. No. 5,457,921, issued to Kostrzecha, discloses a storm shutter in the form of a “kit”. The kit includes a plurality of corrugated shatter-resistant and transparent plastic sheets fastened to the structure using a mounting mechanism and fasteners inserted through keyway slots.
While the use of clear plastic panels, such as Polycarbonate panels, provides light transmittance, the use of plastics can substantially reduce structural integrity and impact resistance as plastics are generally not as strong as the metal alloys, such as aluminum or steel, typically used to fabricate storm panels as disclosed in the background art. Accordingly, the clear polycarbonate storm panel structures of the background art must be fabricated to a greater thickness and/or require additional bracing and hardware that complicates installation and increases cost. For example, the '921 patent discloses corrugated polycarbonate storm panels that use stiffening cross bar members. Furthermore, the '233 patent discloses panels that are strengthened by rods extending through channels. Since weather reporting agencies typically allow a mere 24 hours in which to install storm protection installation time is an important factor.
Accordingly, there exists a need for a light transmitting storm panel assembly that avoids the disadvantages present in the storm panels disclosed in the background art.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a light transmitting storm shutter system for homes, buildings and the like that overcomes the disadvantages present in the background art. A storm panel system according to the present invention includes a combination of corrugated aluminum and clear polycarbonate panels arranged in alternating adjacent relation over a given window or door opening. The aluminum panels provide structural integrity while the polycarbonate panels allow light to pass through the storm shutter system.
More specifically, the storm panel system comprises a combination of full width corrugated aluminum panels with half width corrugated polycarbonate panels installed therebetween in partially overlapping relation. The combination of full width aluminum panels and half width polycarbonate panels provides a storm shutter system that is substantially stronger and more resistant to impact deflection than the light transmitting storm shutters disclosed in the background art, and eliminates the need for additional hardware, supports, bracing etc.
Accordingly, it is an object of the present invention to provide an improved storm shutter assembly for protecting building openings from windborne debris.
Still another object of the present invention is to provide a light transmitting storm panel that has substantial impact resistance.
Yet another object of the present invention is to provide a light transmitting storm panel assembly for protecting building openings from windborne debris in compliance with the latest and strictest building codes.
Still another object of the present invention is to provide a light transmitting storm shutter assembly that achieves a high level of impact resistance without requiring the use of additional stiffeners or cumbersome cross-bracing.
Yet another object of the present invention is to provide a light transmitting panel system capable of being used in an awning or overhang configuration.
In accordance with these and other objects that will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a corrugated full-width metal panel according to the present invention;
FIG. 1A is a perspective view thereof;
FIG. 2 is a cross-sectional view of a corrugated half-width clear polycarbonate panel according to the present invention;
FIG. 2A is a perspective view thereof;
FIG. 3 is an exploded end view showing the panels in relative position for installation;
FIG. 4 is an assembled end view thereof;
FIG. 5 is an exploded perspective view of the panels prior to installation over a window opening;
FIG. 6 is a perspective view of the panels installed over a window opening.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to the drawings, the present invention provides an improved light transmitting storm shutter assembly comprising an alternating series of individual metal (e.g. aluminum or steel) and polycarbonate panels installed in partially overlapping relation. FIGS. 1 and 1A depict a preferred embodiment of a corrugated metal panel, referenced as 10 , according to the present invention. Metal panel 10 preferably comprises a corrugated aluminum panel having a nominal thickness of approximately 0.040″ to 0.063″ (or 18 gauge to 24 gauge if fabricated from steel), and includes corrugated portions resulting in an overall depth of approximately 2.0″. Each panel defines a plurality of apertures 12 , spaced 6.0″ apart and aligned along the width of the panel, for receiving suitable fasteners as more fully disclosed hereinbelow. Metal panel 10 further includes obliquely projecting wing portions 14 formed on opposing sides thereof. The metal panel depicted in FIG. 1 may have an overall width of approximately 15.125″ which width provides a nominal 12.0″ of coverage. For purposes of description herein panel 10 may be referred to as a “full-panel”. Furthermore, the term metal encompasses various metallic materials such as aluminum, and/or suitable gauge steel, or titanium.
FIGS. 2 and 2A depict a preferred embodiment of a corrugated half width panel, referenced as 20 , according to the present invention. Panel 20 preferably comprises a corrugated polycarbonate panel having a nominal thickness of approximately 0.075″, and includes corrugated portions resulting in an overall depth of approximately 2.0″. Each polycarbonate panel 20 defines a plurality of apertures 22 , spaced 6.0″ apart, as seen in FIG. 2, and suitably spaced and aligned along the length of the panel, for receiving suitable fasteners as more fully disclosed hereinbelow. Polycarbonate panel 20 further includes angularly projecting wing portions 24 on opposing ends thereof. As depicted in FIG. 2, panel 20 has an overall width of approximately 8.0″ and provides a nominal 6.0″ of coverage. For purposes of description herein panel 10 may be referred to as a “half-panel”, e.g. a panel width that is approximately one-half the width of a full panel.
FIGS. 3 and 4 illustrate the relative positions of metal panels 10 and polycarbonate panels 20 to form a storm shutter assembly with panels arranged in adjacent, partially overlapping relation to cover an opening. The panel assembly is preferably secured to the structure by fasteners 30 . As best seen in FIG. 3, a nominal 30″ opening may be covered by installation of two full-width metal panels, referenced as 10 A and 10 B, and one half-width polycarbonate panel 20 in adjacent partially overlapping relation. It is important that the polycarbonate panel(s) be positioned on the outer facing side of the metal panels (e.g. metal panels disposed between polycarbonate panels and structure) as the present invention specifically relies on this configuration for providing an assembly that has the greatest strength and impact resistance. More particularly, impact resistance is maximized in the disclosed configuration as the polycarbonate panel(s) 20 is supported from the structure side (e.g. back) by the metal panels 10 , and particularly by the projecting wing portions 14 of each adjacent metal panel. In a preferred embodiment, wing portions 14 are approximately 1.75″ in length. It has been found that wing portions of shorter lengths do not provide sufficient support for the overlapping polycarbonate panel thereby degrading impact resistance of the assembly. The structure disclosed herein has been subjected to impact testing wherein it was unexpectedly found that objects impacting the polycarbonate panel sections result in a certain amount of deflection in the metal panels, and particularly deflection of the wing portions, such that the wing portions each temporarily deflect to a position that is more parallel (e.g. less angled) relative to the wall of the structure. The geometry is such that the deflection causes the wing portions 14 to extend toward the center of the polycarbonate panel 20 during the deflection, thereby directly supporting a larger portion of the polycarbonate panel from the rear. The gap existing between the metal panels 10 A and 10 B, is thus narrowed by deflection of wings 14 A and 14 B. Impact testing confirms that deflection of metal wings 14 provides additional structural support to the inherently weaker polycarbonate panels thereby increasing impact resistance. Conversely, if the wing portions 14 were eliminated or if the polycarbonate panels were positioned on the opposite side of the metal panels impact resistance would be significantly decreased.
Panels 10 and 20 may be mounted using additional mounting hardware, such as an aluminum header, or other suitable hardware, such as known track devices (e.g. “F” Tracks, “C” Tracks, “E” Tracks and the like), anchored to the structure surrounding the opening to be covered. As best seen in FIGS. 3-6, fasteners 30 are preferably used to anchor the panels to the structure and/or to fasten the panels in overlapping configuration. As best depicted in FIGS. 5 and 6, a light transmitting, impact resistant storm shutter assembly is formed by anchoring a sufficient number of metal panels 10 and clear polycarbonate panels 20 to cover an opening of any given width. FIG. 6 depicts a storm shutter assembly according to the present invention installed on a building in covering relation with a window opening.
As should be apparent, the use of light transmitting (e.g. transparent and/or translucent) plastic half panels allows available ambient light to pass through the installed storm shutter assembly into the protected structure thereby avoiding a significant disadvantage present with conventional all Aluminum and/or Steel storm shutters. Furthermore, the use of half width polycarbonate panels disposed between full width Aluminum and/or Steel panels provides a barrier that is sufficiently resistant to impact so as to comply with even the most stringent codes. In addition, the assembly disclosed herein allows for the use of thinner/less expensive polycarbonate panels thereby providing a light transmitting storm shutter assembly that offers impact resistance at a lower cost than an all polycarbonate assembly.
The storm shutter assembly disclosed herein has been tested in accordance with the 1999 Standard Building Code, SSTD 12-99, a test standard for determining impact resistance from windborne debris. The panels disclosed herein are also suitable for use in connection with roof openings (e.g. skylights). In addition, the panels may be configured for use as an awning. Finally, since polycarbonate is more costly than aluminum or steel, the alternating Aluminum and polycarbonate panel configuration provides a light transmitting storm shutter that is far less costly than the all polycarbonate storm shutters disclosed in the background art.
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 therefrom within the scope of the invention and that obvious structural and/or functional modifications will occur to a person skilled in the art.
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A light transmitting storm shutter system for homes, buildings and the like includes a combination of full width corrugated aluminum and half width clear polycarbonate panels arranged in alternating adjacent and partially overlapping relation over a given window or door opening. The aluminum panels provide structural integrity while the polycarbonate panels provide light transmittance. The combination of full width aluminum panels and half width polycarbonate panels provides a storm shutter system that is substantially stronger and more resistant to impact deflection than the light transmitting storm shutters disclosed in the background art, and eliminates the need for additional hardware, supports, and bracing.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of Chinese Application No. 201310596082.6 filed on Nov. 22, 2013 and entitled “Ferroporphyrin solid dispersion and preparation method therefor”, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a solid dispersion comprising ferroporphyrin as an active ingredient, a method of preparing said solid dispersion, and a solid formulation comprising said solid dispersion.
BACKGROUND OF THE INVENTION
[0003] Iron, as an important nutritional element, is essential to human body. The deficiency or poor availability of iron might lead to disorders of metabolic processes such as transportation and storage of oxygen, transportation of carbon dioxide as well as oxidations and reductions, influence growth and development, and even lead to various diseases such as anemia; and iron deficiency anemia (IDA) will occur if the storage or intake of iron is insufficient. IDA refers to anemia which occurs when storage iron in the body available for producing hemoglobin has been depleted and erythropoiesis disorder develops. It is one of nutritional deficiency diseases with the highest incidence rate, and is common in children, pregnant and lactating women as well as patients with chronic diseases. According to a report from WHO (World Health Organization), about 10%-30% of the populations in the world suffer from iron deficiency at different levels, wherein the incidence rate is about 10% in male and >20% in female. An investigation shows that there are up to 38 million people suffering from anemia at different levels in China.
[0004] Nowadays, the prevention and treatment of iron deficiency anemia is mainly effected by iron supplementing agents. Conventional iron supplement agents include ferrous sulfate, ferrous chloride, ferrous gluconate, ferrous lactate, ferrous succinate, ferrous fumarate, etc. Although these iron supplement agents have high iron contents and good iron supplementing effects, they have a special rusty taste and are not suitable for long term consumption. In addition, they have low availability in human body and have significant adverse effects (various symptoms are prone to occur, e.g. bad smell, nausea, bloating, disorders of digestive organs, diarrhea, and constipation). Further, ferrous iron is unstable in gastrointestinal tract, and is prone to oxidation into ferric iron. Iron contained in heme of hemoglobin is in the form of ferrous iron, which will thus lead to low availability thereof in human body.
[0005] Ferroporphyrin (Porphyrin iron) belongs to natural substances, and is conventionally extracted from pig blood. It is a main component of erythrocytes and thus is also known as “heme”. It is an iron porphyrin complex consisting of porphyrin and one molecular unit of ferrous iron. Porphyrin iron, known as a superior iron supplementing product, is free from being influenced by phosphoric acid, carbonic acid, tannic acid, oxalic acid, phytic acid, etc. and can be absorbed into blood directly by intestinal mucosa. Its bioavailability is lightly higher than conventional iron supplementing agents.
[0000]
[0006] Although it has good iron supplementing effects, porphyrin iron has a special blood smell and consequently a poor taste, since it is extracted from pig blood. In addition, porphyrin iron is structrually unstable and prone to oxidation, and it also has an irritating effect on the digestive tract, e.g. stomach burning, nausea, etc., resulting in poor patient compliance to administration. Porphyrin iron is soluble in sodium hydroxide solution, hot alcohols or ammonia and slightly soluble in hot pyridine, but insoluable in water, diluted acids, ethers, chloroform, etc. Its absorption in gastrointestinal tract is limited by its relatively poor water solubility. According to a report by Zhao Di (Absorption Of 58 Iron Originating From Hemin In Rat Using Extrinsically Label Method, Chinese Journal of Clinical Pharmacology and Therapeutics, 2012, 17(6): 639-643), the absolute oral bioavailability of porphyrin iron in rats is only 0.93%. On the other hand, porphyrin iron has an extremely low iron content in heme. As shown in the above structure, 6 rings of porphyrin are complexed with an iron atom, and thus during the absorption process, the ferrous ion can be released only after the 6 rings of porphyrin are destroyed. Therefore, in order to improve iron supplementing effects, the dosage of porphyrin iron should generally be increased. However, the increase in dosage will decrease the patient compliance to administration, leading to poor iron supplementing effects. Therefore, such disadvantages largely limit the development and application of porphyrin iron in foods and health products.
[0007] Most of current commercial porphyrin iron products are conventional porphyrin iron capsules without significant improvements in terms of the blood smell and irritations to digestive tract. In addition, oral porphyrin iron solution has been developed, to which casein phosphopeptides (CPP) for improving iron adsorption and Vitamins are added. This product not only fails to ameliorate the blood smell and digestive tract irritations or improve bioavailability of porphyrin iron, but also limits the application thereof, since CPP induces allergic responses in patients allergic to milk or seafoods due to the allergenicity of CPP.
[0008] Many patents and literatures relating to porphyrin iron have been disclosed and published, most of them focus on the extraction and preparation thereof, but few focus on ameliorating its blood smell or reducing its digestive tract irritations.
[0009] CN101254207A discloses a liposome preparation comprising porphyrin iron and/or inorganic iron, and preparation process thereof, wherein a liposome comprising porphyrin iron and/or inorganic iron, cholesterol and lecithin is prepared by utilizing a rotary thin film-ultrasonic process. The liposome preparation improves stability and bioavailability of porphyrin iron. However, the porphyrin iron liposome prepared by the process has an encapsulation rate of only 30-36%, and the lecithin in the preparation is prone to oxidation and is of high cost. In addition, the liposome per se has poor physical stability, which is unfavorable for storage and transportation and makes industrial production thereof difficult.
[0010] CN102726738A discloses an oil suspension type soft capsule with iron supplementing function, comprising iron materials (porphyrin iron/ferrous fumarate), Vitamin C, casein phosphopeptides, soybean oil, folic acid, beeswax, and gelatin capsule shells. Although the soft capsule can mask some of the blood smell and the Vitamin C and casein phosphopeptides added can improve the adsorption of iron in human body, Vitamin C per se is unstable and is prone to oxidation. Furthermore, there is a risk that CPP may induce allergies in patients allergic to milk or seafoods. Also, the soft capsule per se has a significant stability problem, i.e., the component of the capsule shell, gelatin, is prone to aging due to crosslinking reaction, resulting in a change in dissolubility of the capsule shell and thereby influencing the disintegration rate of the soft capsule. Furthermore, propylene glycol and sorbitol used in the capsule shell are prone to oxidation during storage, forming some low molecular weight aldehydes, thereby accelerating the crosslinking reaction of gelatin and in turn delaying the disintegration of the soft capsule.
[0011] Therefore, there is still a need for a porphyrin iron preparation which can not only overcome the disadvantages of porphyrin iron per se but also incorporate some stable, low cost and non-allergic adjuvants. In the meantime, it is desired to obtain a porphyrin iron composition with ameliorated digestive tract irritations and improved mouthfeel, bioavailability and/or stability by a simple and easy-operable formulation process.
SUMMARY OF THE INVENTION
[0012] In one aspect, the present invention provides a porphyrin iron solid dispersion, comprising porphyrin iron and a carrier material, wherein said carrier material is selected from one or more of polymers comprising vinylpyrrolidone units, or mixtures thereof; polymers comprising ethylene glycol units; and celluloses or cellulose esters.
[0013] In an embodiment of the present invention, porphyrin iron is dispersed in said carrier material at molecular level.
[0014] In another embodiment of the present invention, said polymers comprising vinylpyrrolidone units, or mixtures thereof are selected from one or more of polyvinylpyrrolidone, a mixture of polyvinylpyrrolidone and polyvinyl acetate, and a copolymer of vinylpyrrolidone and vinyl acetate.
[0015] In a further embodiment of the present invention, said polymers comprising vinylpyrrolidone units, or mixtures thereof have a K value of about 10-95, preferably 25-70. Said K value, also referred to as Fikentscher K value, is conventionally used in the art and is a measure of molecular weights of polymers comprising vinylpyrrolidone units, or mixtures thereof. It can be determined using a 1 wt. % aqueous solution according to a method as described in H. Fikentscher, Cellulose-Chemie, 1932, 13:58-64/71-74.
[0016] In a further embodiment of the present invention, the weight ratio of polyvinylpyrrolidone and polyvinyl acetate in said mixture of polyvinylpyrrolidone and polyvinyl acetate is about 1:9 to about 9:1, preferably about 2:8 to about 8:2.
[0017] In a further embodiment of the present invention, the weight ratio of vinylpyrrolidone units and vinyl acetate in said copolymer of vinylpyrrolidone and vinyl acetate is about 1:9 to about 9:1, preferably about 4:6 to about 6:4.
[0018] In a further embodiment of the present invention, said polymers comprising ethylene glycol units are copolymers of polyethylene glycol/vinyl caprolactam/vinyl acetate.
[0019] In a further embodiment of the present invention, said celluloses or cellulose esters are selected from one or more of methyl cellulose, hydroxymethyl cellulose, hydroxylethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose and hydroxypropylmethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, carboxymethyl ethyl cellulose, hydroxypropylmethyl cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, and cellulose acetate phthalate, preferably hydroxypropylmethyl cellulose acetate succinate.
[0020] In a further embodiment of the present invention, in said hydroxypropyl cellulose acetate succinate, the content of the acetate group is about 8 wt. % to about 12 wt. %, and the content of the succinate group is about 6 wt. % to about 15 wt. %, based on the weight of said hydroxypropyl cellulose acetate succinate.
[0021] In a further embodiment of the present invention, the weight ratio of porphyrin iron to said carrier material in said porphyrin iron solid dispersion is about 1:1 to about 1:10, preferably about 1:1 to about 1:4, and more preferably about 1:1 to about 1:3.
[0022] In a further embodiment of the present invention, the porphyrin iron solid dispersion further comprises a pharmaceutically acceptable pharmaceutical adjuvant selected from one or more of surfactants, diluents, disintegrants, binders, and lubricants.
[0023] In another aspect, the present invention provides a process of preparing said porphyrin iron solid dispersion, including:
[0024] either feeding a homogenously mixed mixture of porphyrin iron and a carrier material at a weight ratio of 1:1 to 1:10, preferably 1:1 to 1:4, more preferably 1:1 to 1:3, and an optional pharmaceutically acceptable pharmaceutical adjuvant, or simply feeding porphyrin iron and a carrier material at said weight ratio and an optional pharmaceutically acceptable pharmaceutical adjuvant, into a hot melt extruder preheated to about 120° C. to about 180° C.; and
[0025] cooling, pulverizing, and sieving the extruded mixture, to obtain the porphyrin iron solid dispersion.
[0026] In another aspect, the present invention provides a pharmaceutical composition comprising said porphyrin iron solid dispersion, wherein the pharmaceutical composition is in the form of powders, granules, pills, capsules, or tablets.
[0027] In an embodiment of the present invention, said pharmaceutical composition further comprises a pharmaceutically acceptable pharmaceutical adjuvant selected from one or more of a surfactant, a diluent, a disintegrant, a binder, and a lubricant.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Unless defined otherwise, the technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention belongs. In case of discrepancy, the definitions provided in this application shall prevail.
[0029] When a certain quantity or concentration, or other values or parameters are represented in the form of ranges, preferred ranges, or preferred upper limit values or preferred lower limit values, it should be understood that this equals to that any ranges defined by combining any upper limits of the ranges or preferred values and any lower limits of the ranges or preferred values have been specifically suggested, regardless whether said ranges have been specifically disclosed. Unless indicated otherwise, a numerical range as listed herein is intended to include endpoints of the range and any integers and fractions within the range.
[0030] It should be understood that the term “about”, when describing a value, or an endpoint of a range, is intended to include the specific value or related endpoint.
[0031] Unless indicated otherwise, all percentages, parts, and ratios as used herein are given by weight.
[0032] The present invention will be described in details below.
[0033] The present invention provides a porphyrin iron solid dispersion. As compared to prior art, the solid dispersion according to the present invention in which porphyrin iron is dispersed at molecular level, has advantages such as improved mouthfeel, low digestive tract irritation, high bioavailability, and high stability. Furthermore, the solid dispersion can be prepared by employing a hot melt extrusion process according to the present invention which is simple and easy-operable. Specifically, it has been found that a carrier material and porphyrin iron at a certain ratio can be prepared into a solid dispersion in which porphyrin iron is dispersed at molecular level after treatment with the hot melt extrusion process according to the present invention. Unexpectedly, it is found that the solid dispersion in which porphyrin iron is dispersed at molecular level can mask the blood smell of porphyrin iron, improve the mouthfeel of porphyrin iron significantly, reduce the irritations to digestive tract, such as symptoms e.g. stomach burning and nausea, induced by porphyrin iron, while significantly improving the solubility, in vitro dissolution rate and bioavailability of porphyrin iron. In addition, the hot melt extrusion process can also increase the chemical stability of porphyrin iron, and the process is simple and fairly good at repeatability.
[0034] The term “being dispersed at molecular level” in the present invention has a common meaning known by a person skilled in the art. Specifically, it means that porphyrin iron is dispersed in said carrier material at molecular level, forming a single-phase solid dispersion or solid solution. The Tg value of the resultant porphyrin iron solid dispersion is different from that of the carrier material.
[0035] The present invention provides a solid dispersion comprising porphyrin iron and a carrier material. Carrier materials suitable for the present invention include, but are not limited to, one or more of polymers comprising vinylpyrrolidone units, or mixtures thereof; polymers comprising ethylene glycol units; and celluloses or cellulose esters.
[0036] Said polymers comprising vinylpyrrolidone units, or mixtures thereof, suitable as the carrier, can be selected from one or more of polyvinylpyrrolidone, a mixture of polyvinylpyrrolidone and polyvinyl acetate, and a copolymer of vinylpyrrolidone and vinyl acetate.
[0037] Polyvinylpyrrolidone, also referred to as povidone, can be prepared, e.g., by free radical polymerization of vinylpyrrolidone in water or 2-propanol. Polyvinylpyrrolidone has a K value of about 10 to about 95, wherein the K value has the definition as described above. Polyvinylpyrrolidone suitable for the present invention can be purchased as, for example, Plasdone®K12, Plasdone®K17, Plasdone®K25, Plasdone®K29/32, Plasdone®K90 or Plasdone®K9OD from International Specialty Products, or Kollidon®12PF, Kollidon®17PF, Kollidon®25, Kollidon®30, or Kollidon®90F from BASF, but is not limited thereto.
[0038] The weight ratio of polyvinylpyrrolidone to polyvinyl acetate in the mixture of polyvinylpyrrolidone and polyvinyl acetate, suitable as the carrier in the present invention, is about 1:9 to about 9:1, more preferably about 2:8 to about 8:2. Said mixture has a K value of about 50 to about 70. Said mixture of polyvinylpyrrolidone and polyvinyl acetate can be prepared, e.g., by physically mixing polyvinylpyrrolidone and polyvinyl acetate at the above mentioned ratio by spray drying. Said mixture of polyvinylpyrrolidone and polyvinyl acetate can also be, e.g., a mixture of polyvinylpyrrolidone and polyvinyl acetate at a weight ratio of 1:9 to 4:6, as disclosed in CN1227002C. The mixture of polyvinylpyrrolidone and polyvinyl acetate that can be used in the present invention can also be, e.g. the commercial product Kollidon®SR from BASF, which is a spray dried physical mixture of polyvinylpyrrolidone and polyvinyl acetate at a weight ratio of 2:8. In a preferred embodiment of the present invention, said carrier is Kollidon®SR.
[0039] The copolymer of vinylpyrrolidone and vinyl acetate, suitable as the carrier in the present invention, can be prepared, e.g., by carrying out free radical polymerization of N-vinylpyrrolidone and vinyl acetate in 2-propanol. Said copolymer of vinylpyrrolidone and vinyl acetate can also be a copolymer of vinylpyrrolidone and vinyl acetate at a weight ratio of 15:85-40:60, as disclosed in U.S. Pat. No. 5,426,163A. The weight ratio of vinylpyrrolidone and vinyl acetate in the copolymer suitable as the carrier in the present invention, is about 1:9 to about 9:1, preferably about 4:6 to about 6:4, and the copolymer has a K value of about 25 to about 70. The copolymer of vinylpyrrolidone and vinyl acetate that can be used in the present invention can also be, e.g. commercial product Kollidon®VA 64 from BASF and commercial product Plasdone®5630 from International Specialty Products (both are copolymers of vinylpyrrolidone and vinyl acetate at a weight ratio of 6:4), but is not limited thereto. In a preferred embodiment of the present invention, said carrier is Kollidon®VA 64.
[0040] The polymer comprising ethylene glycol units, suitable as the carrier in the present invention, can be, e.g., a copolymer of polyethylene glycol/vinyl caprolactam/vinyl acetate which can be, e.g., the commercial product Soluplus® from BASF. In a preferred embodiment of the present invention, said carrier is Soluplus®.
[0041] Celluloses suitable as the carrier in the present invention can be, e.g., methyl cellulose (MC), hydroxymethyl cellulose (HMC), hydroxylethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose (HEMC) and hydroxypropylmethyl cellulose (HPMC), carboxymethyl cellulose (CMC), sodium carboxymethyl cellulose (CMC-Na), carboxymethyl ethyl cellulose (CMEC). Cellulose esters suitable as the carrier in the present invention can be, e.g., hydroxypropylmethyl cellulose acetate succinate (HPMCAS), hydroxypropylmethyl cellulose phthalate (HPMCP), and cellulose acetate phthalate (CAP). In a preferred embodiment of the present invention, said carrier material is hydroxypropyl cellulose acetate succinate, wherein the content of the acetate group is about 8 wt. % to about 12 wt. %, and the content of the succinate group is about 6 wt. % to about 15 wt. %, based on the weight of said hydroxypropyl cellulose acetate succinate; and said hydroxypropyl cellulose acetate succinate can be, e.g., commercial products AQOAT AS-L, AS-M and AS-H from Shin-Etsu. In a preferred embodiment of the present invention, said carrier is AQOAT AS-M.
[0042] In addition to the aforesaid carrier materials, polymethacrylic acids and salts thereof, methacrylate copolymers, aminoalkyl methacrylate copolymers; polyvinyl alcohol (PVA) and other materials, combinations thereof, and their combinations with the aforesaid materials can also be used as the carrier material according to the present invention.
[0043] The ratio of porphyrin iron, as the active ingredient, to the carrier material in the present invention is not specifically limited, and can be adjusted according to actual demands. Typically, the weight ratio of porphyrin iron to said carrier material is about 1:1 to about 1:10, preferably about 1:1 to about 1:4, and most preferably about 1:1 to about 1:3.
[0044] In another aspect, the present invention also provides a process of preparing the porphyrin iron solid dispersion according to the present invention, which includes, but is not limited to, hot extrusion process and spray drying process. For example, the hot extrusion process includes the following particular steps:
[0045] either feeding a homogenously mixed mixture of porphyrin iron and the carrier material at the above-mentioned weight ratio, and an optional pharmaceutically acceptable pharmaceutical adjuvant, or simply feeding porphyrin iron and the carrier material at the above-mentioned weight ratio and an optional pharmaceutically acceptable pharmaceutical adjuvant, into a hot melt extruder preheated to about 120° C. to about 180° C.; and
[0046] cooling, pulverizing, and sieving the extruded mixture, to obtain the porphyrin iron solid dispersion.
[0047] The way to carry out the cooling described in the preparation process according to the present invention is not specifically limited, and it can include air cooling, water cooling, mechanical cooling, etc.
[0048] The type of the extruder suitable for the present invention is not specifically limited. It includes, but is not limited to, a single-screw or twin-screw hot melt extruder. In an embodiment of the present invention, the extruder for preparing the porphyrin iron solid dispersion according to the present invention is a twin-screw extruder. In that case, the rotation mode of the screw is not specifically limited, and it can include, but is not limited to, co-rotating twin screws, counter-rotating twin screws, and conical twin-screw rotating modes. In an embodiment of the present invention, the extruder for preparing the porphyrin iron solid dispersion according to the present invention is a co-rotating twin-screw extruder.
[0049] The melting temperature of the hot melt extruder is set to about 120° C. to about 180° C., and the rotation speed is set to about 50 to about 500 rpm. The length to diameter ratio (L/D) of the screw can be selected from about 15 to about 40. If the melting temperature is too low, the L/D is too low, or the rotation speed of the screw is too slow, then insufficient heat energy or mechanic energy will be provided during the hot melting process, and thus porphyrin iron (or the carrier material) will not achieve a melting state, or porphyrin iron will not dissolve in the molten carrier material. In that case, although being well mixed, porphyrin iron and the carrier material cannot form a single-phase solid dispersion which is dispersed at molecular level (solid solution). If the melting temperature is too high, the L/D is too high, or the rotation speed of the screw is too fast, then excess heat energy or mechanic energy will be provided during the hot melting process. In that case, even though a single-phase solid dispersion in which porphyrin iron is dispersed at molecular level (solid solution) is formed, unnecessary degradation of porphyrin iron and/or the carrier material will be caused.
[0050] Furthermore, the present invention also provides a pharmaceutical composition comprising the porphyrin iron solid dispersion. In an embodiment of the present invention, said pharmaceutical composition is in the form of powders, granules, pills, capsules, or tablets.
[0051] The porphyrin iron solid dispersion according to the present invention can also comprise a pharmaceutically acceptable pharmaceutical adjuvant. Moreover, the pharmaceutical composition according to the present invention can further be combined with a pharmaceutically acceptable pharmaceutical adjuvant according to actual demands, to form various solid dosage forms.
[0052] Said pharmaceutically acceptable pharmaceutical adjuvant includes, but is not limited to, one or more of surfactants, diluents, disintegrants, binders, and lubricants. Said surfactants are, e.g., polyethylene oxide-polypropylene oxide copolymers, such as poloxamer; and copolymers of polyethylene glycols, such as the Vitamin E polyethylene glycol 1000 succinate product from BASF, Kolliphor®TPGS. In a preferred embodiment of the present invention, said porphyrin iron solid dispersion comprises, as the surfactant, Vitamin E polyethylene glycol 1000 succinate. Said diluents can be one or more of microcrystalline cellulose, starch, pregelatinized starch, lactose, mannitol, and calcium hydrogen phosphate. Said disintegrants can be one or more of a low-substituted cellulose, croscarmellose sodium, sodium carboxymethyl starch, crosslinked polyvinylpyrrolidone. Said binders can be one or more of sodium carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose or hydroxypropylmethyl cellulose. Said lubricants can be one or more of magnesium stearate, talc powder, micronized silica gel, stearic acid, and hydrogenated vegetable oils.
DESCRIPTION OF THE DRAWINGS
[0053] The above and other objects and features of the present invention will be apparent with reference to the following figures.
[0054] FIG. 1 : Influences of the weight ratio of carrier material/active pharmaceutical ingredient in the porphyrin iron-Kollidon®VA 64 solid dispersions of various formulae on the solubility of porphyrin iron.
[0055] FIG. 2 : Photographs for the solubility of the porphyrin iron-Kollidon®VA 64 solid dispersions of various formulae, wherein A corresponds to Formula 1-1, B corresponds to Formula 1-2, and C corresponds to Formula 1-4.
[0056] FIG. 3 : Profiles for in vitro dissolution of the porphyrin iron-Kollidon®VA 64 solid dispersions of various formulae.
[0057] FIG. 4 : Profiles for dissolution of the porphyrin iron-Kollidon®VA 64 solid dispersions of various formulae under simulated in vivo conditions, wherein FIG. 4 a is a profile for in vitro dissolution under simulated gastric fluid in the fasted conditions, and FIG. 4 b is a profile for in vitro dissolution under simulated gastric fluid in the fed conditions.
[0058] FIG. 5 : Influences of the ratio of carrier material/active pharmaceutical ingredient in the porphyrin iron-Soluplus® solid dispersion of Formula 1-2 on the solubility of porphyrin iron.
[0059] FIG. 6 : Photographs for the solubility of the porphyrin iron-Soluplus® solid dispersions of various formulae, wherein A corresponds to Formula 2-1, B corresponds to Formula 2-2, and C corresponds to Formula 2-3.
[0060] FIG. 7 : Influences of the ratio of carrier material/active pharmaceutical ingredient in porphyrin iron-HPMCAS solid dispersions on the solubility of porphyrin iron.
[0061] FIG. 8 : Photographs for the solubility of porphyrin iron-HPMCAS solid dispersions of various formulae, wherein A corresponds to Formula 3-1, B corresponds to Formula 3-2, and C corresponds to Formula 3-3.
EXAMPLES
[0062] Examples are provided below in order to describe the present invention in more details. The following examples are for the purpose of illustration only, and are not intended in any way to limit the present invention. A person skilled in the art will readily be aware of various non-critical parameters, and is able to modify or change these parameters to obtain substantially the same results.
[0063] Preparation of Porphyrin Iron-Kollidon®VA 64 Solid Dispersions
Example 1-1
Preparation of Porphyrin Iron-Kollidon®VA 64 Solid Dispersions
[0064] The particular weight ratios in various solid dispersion formulae are shown in Table 1-1.
[0000]
TABLE 1-1
Specific composition of various solid dispersion formulae
Names of
raw materials
Amounts of raw materials and adjuvants (g)
and adjuvants
Formula 1-1
Formula 1-2
Formula 1-3
Formula 1-4
porphyrin iron
35
50
50
20
Kollidon ®
35
150
150
200
VA 64
Kolliphor ®
None
None
20
None
TPGS
[0065] Preparation process: Porphyrin iron and the carrier materials in the amounts shown in the formulae in Table 1-1 were added to a mixer separately and mixed homogenously. Alternatively, porphyrin iron and the carrier materials in the amounts shown in the formulae in Table 1-1 were fed into the loading hopper of a co-rotating twin screw extruder (Omicron 12, Steer Engineering Private Limited, India). The melting temperature in the co-rotating twin screw extruder was controlled at between about 120° C. and about 180° C., and the rotation speed of the screw was about 50 to about 500 rpm. The extruded mixtures were cooled, pulverized, and sieved, to obtain the solid dispersion.
[0066] Evaluation on the Physical and Chemical Properties of the Porphyrin Iron-Kollidon®VA 64 Solid Dispersions
Test Example 1-2
Determination of Glass Transition Temperature (Tg) of the Solid Dispersions
[0067] >3 mg of the active pharmaceutical ingredient (API) porphyrin iron, extruded blank material prepared from Kollidon®VA 64, and materials prepared according to the formulae in Table 1-1 were precisely weighted separately, and were subjected to differential scanning calorimetry analysis (mDSC analysis, TA Q2000 Differential Scanning calorimeter). The test results showed that no melting point or Tg value was determined in the scanning of the API porphyrin iron (crystalline type) in the temperature range of 40-180° C., since crystalline porphyrin iron was completely decomposed before the melting point was reached. The blank Kollidon®VA 64 solid dispersion had a Tg value of 98.73° C. and Formula 1-2 had a Tg value of 101.3° C. The Tg value of Formula 1-2 showed a significant deviation as compared to the blank solid dispersion and also was different from the Tg value of porphyrin iron, indicating that porphyrin iron was in the state of being dispersed at molecular level in the dispersion, it formed a solid dispersion or a solid solution with the carrier adjuvant.
Test Example 1-3
Determination of the Content of Porphyrin Iron in the Solid Dispersions
[0068] Sample preparation: an appropriate amount of the solid dispersion of each formula was weighted, and was dissolved in 0.1N aqueous NaOH solution, to prepare a test sample with a porphyrin iron concentration of about 50 μg/ml. Analysis was conducted by an HPLC method. The method for determining the content was as follows, and the results were shown in Table 1-2.
[0000]
Chromatography column
C18 column (3 μm, 3.0 × 50 mm)
Mobile phase
0.2% phosphoric acid/methanol = 25:75
Flow rate
1 ml/min
Sample disk
Room temperature
Wavelength
401 nm
Sample injection
10 μl
Analysis period for single
About 2 min
sample injection
[0000]
TABLE 1-2
Content determination results for each solid dispersion formula
Formula
Formula 1-1
Formula 1-2
Formula 1-3
Formula 1-4
Labelled
93.3
95.7
97.1
96.5
amount (%)
[0069] As can be seen from Table 1-2, the labelled amounts of the drug for all formulae were >93%, indicating that the hot melt extrusion process had little influence on the stability of the drug. The relatively lower labelled amounts of the drug were due to about 3%-6% of water contained in the solid dispersions.
Test Example 1-4
Determination of the Apparent Solubility of the Solid Dispersions
[0070] Sample preparation: Excess amounts of porphyrin iron solid dispersions of various formulae and physical mixtures of porphyrin iron and carrier materials (prepared by weighting the active pharmaceutical ingredient and the carrier adjuvants in the amounts shown in the formulae and simply mixing them) were weighted separately, and placed in appropriate containers, a phosphate buffer solution having a pH of 6.8 and a volume of about 2/3 of the volume of the container was added, and then it was placed in a shaking table at 37° C. and was shaken for 24 h. The resultant solution was filtered through a 0.45 μm filter membrane, and then the filtrate was collected, further diluted with an appropriate amount of 0.1N NaOH, and analyzed by HPLC after vortex mixing. The analysis method was the same as the method for the content determination for the solid dispersions in Example 1-3. The determination results were shown in Table 1-3.
[0000]
TABLE 1-3
Determination results of porphyrin iron solubility
for each solid dispersion formula
Formula
Formula
Formula
Formula
Formula
1-1
1-2
1-3
1-4
API
A 1)
B 2)
A
B
B
A
B
Solubility
<0.2
2.5
239.9
1.2
606.3
126.4
1.1
360.6
(μg/ml)
Solubility
— 3)
>1200
>3032
>632
>1803
ratio (solid
dispersion/API)
Solubility
—
96
505
79
328
ratio (solid
dispersion/
physical
mixture)
1) “A” represents a physical mixture (not a solid dispersion of the present invention) with the same composition as sample B.
2) “B” represents a solid dispersion of the present invention.
3) “—” means that there is no determined value.
[0071] As can be seen from the solubility determination results in Table 1-3, all solid dispersions of various formulae prepared by a hot melt extrusion process had significant solubilizing effects on porphyrin iron, indicating that Kollidon®VA 64 had fairly good solubilizing effects on porphyrin iron. As can be seen from the results obtained from a single-variable design of experiment (DOE), there is a certain relationship between the weight ratio of the carrier (Kollidon®VA 64) to the API porphyrin iron in the solid dispersions and the solubility of porphyrin iron in the solid dispersions, as shown in FIG. 1 . Especially, the solubility of porphyrin iron in the solid dispersions reached its maximum when the weight ratio of the carrier to the API porphyrin iron was 3:1. In FIG. 2 , when being dispersed in the buffer at pH 6.8 for 3 min, all the prepared solid dispersions of various formulae had colors significantly deeper than those of the physical mixtures, indicating that the solid dispersions, which were prepared with the carriers and in which porphyrin iron was in the state of being dispersed at molecular level, could largely increase the solubility of porphyrin iron.
Test Example 1-5
In Vitro Dissolution Tests for the Solid Dispersions
[0072] Conditions for the Dissolution Tests:
[0000]
Dissolution method
USP Method II (Paddle)
Dissolution medium
pH 1.2/pH 6.8
Medium volume
900 ml
Rotation speed
100 rpm
Temperature
37.5° C.
Tested dosage
50 mg (porphyrin iron)/cup
[0073] Analysis method for sample dissolution: the same as that for the content determination for the solid dispersions in Example 1-3.
[0074] The in vitro dissolution results for the solid dispersions were shown in Table 1-4 and Table 1-5.
[0000]
TABLE 1-4
Results of the dissolution tests for solid dispersions
of various formulae in the dissolution medium at pH 1.2
Concentrations of dissolved API
at various time points (μg/ml)
Test
5
10
15
30
45
60
samples
min
min
min
min
min
min
Physical
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
mixture 1)
Formula 1-1
55.1
52.8
55.7
52.8
54.9
54.3
Formula 1-2
52.2
54.0
52.6
54.3
54.0
53.9
Formula 1-3
48.8
51.3
49.6
49.7
49.5
49.1
Formula 1-4
45.4
46.8
49.0
49.8
47.2
49.0
1) said physical mixture was prepared according to the specific composition of Formula 1-2.
[0000]
TABLE 1-5
Results of the dissolution tests for the solid dispersions
of various formulae in the dissolution medium at pH 6.8
Concentrations of dissolved API
at various time points (μg/ml)
Test
15
30
45
60
120
180
samples
min
min
min
min
min
min
Physical
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
mixture 1)
Formula 1-1
56.8
56.1
55.9
56.0
55.8
54.8
Formula 1-2
54.2
54.9
53.6
53.8
53.8
54.5
Formula 1-3
45.9
46.3
44.4
42.5
45.8
47.8
Formula 1-4
55.1
55.4
55.2
54.3
54.9
54.2
1) said physical mixture was prepared according to the specific composition of Formula 1-2.
[0075] As can be seen from Table 1-4 and Table 1-5, as compared to the physical mixture, solid dispersions of various formulae prepared by using Kollidon®VA 64 as the carrier material could largely increase the concentration of dissolved porphyrin iron and the dissolution rate of porphyrin iron at pH 1.2 and pH 6.8. FIG. 3 shows profiles for in vitro dissolution of the porphyrin iron-Kollidon®VA 64 solid dispersions of various formulae and the physical mixture of porphyrin iron-Kollidon®VA 64 in the medium at pH 6.8, wherein the concentration of the physical mixture at each time point was lower than that represented by the dotted line in the figure.
Test Example 1-6
Dissolution Tests Under Stimulated In Vivo Conditions
[0076] The pH of gastric fluid is about 1.2 and that of intestinal fluid is about 6.8 in human in the fasted conditions. The pH of gastric fluid might be still as low as 1.2 and that of intestinal fluid is about 5.0 due to the influences from foods. In this test example, Formula 1-2, having a maximal solubility, was selected for dissolution tests under stimulated in vivo conditions. The test conditions were shown below.
[0000]
Dissolution
USP method II (Paddle)
method
Dissolution
A medium of pH 1.2→6.8: 800 ml of a dissolution
medium
medium of pH 1.2 was sampled over 30 min, and then
100 ml of a prepared buffer solution was immediately
added so that the pH of the overall dissolution medium
was 6.8.
A medium of pH 1.2→5.0: 800 ml of a dissolution
medium of pH 1.2 was sampled over 30 min, and then
100 ml of a prepared buffer solution was immediately
added so that the pH of the overall dissolution medium
was 5.0.
Rotation speed
100 rpm
Temperature
37.5° C.
Tested dosage
60 mg (porphyrin iron)/cup
[0077] Analysis method for sample dissolution: the same as that for the content determination for the solid dispersions in Example 1-3.
[0078] The in vitro dissolution results for the solid dispersions were shown in Table 1-6 and Table 1-7.
[0000]
TABLE 1-6
Results of the dissolution test for Formula
1-2 during medium transition pH 1.2→6.8
Dissolution at various time points (%)
pH 1.2
pH 6.8
Test
5
10
15
30
45
60
120
180
sample
min
min
min
min
min
min
min
min
Formula 1-2
103.0
106.5
104.7
104.3
109.3
108.6
106.5
106.7
[0000]
TABLE 1-7
Results of the dissolution test for Formula
1-2 during medium transition pH 1.2→5.0
Dissolution at various time points (%)
pH 1.2
pH 5.0
Test
5
10
15
30
45
60
120
180
sample
min
min
min
min
min
min
min
min
Formula 1-2
81.2
84.9
85.5
83.5
92.3
95.1
93.3
93.2
[0079] As can be seen from Table 1-6 and Table 1-7, the dissolution of Formula 1-2 under both stimulated in vivo fasted conditions (pH 1.2→6.8 medium transition) and fed conditions (pH 1.2→5.0 medium transition) were above 80%, indicating that the transition from gastric fluid to intestinal fluid of different pH had little influence on the dissolution of the solid dispersion of Formula 1-2.
Test Example 1-7
Stability Test for the Solid Dispersions
[0080] A certain amount of the API porphyrin iron and the solid dispersion of Formula 1-2 were placed in 30 mL brown glass vials, and the method of the sample stability test was the same as the method for the content determination for the solid dispersions in Example 1-3. The test results were shown in Table 1-8 and Table 1-9.
[0000]
TABLE 1-8
Content determination results of the stability study for the porphyrin
iron-Kollidon ®VA 64 solid dispersion (open)
Test period
Test
0
1
3
7
35
Samples
conditions
day
day
days
days
days
API
25° C.
100.9%
98.0%
98.7%
100.9%
98.8%
Formula 1-2
60% RH
100.5%
97.6%
97.9%
98.6%
97.8%
API
40° C.
100.9%
99.0%
99.8%
100.8%
100.6%
Formula 1-2
75% RH
100.5%
98.3%
96.2%
96.9%
97.6%
[0000]
TABLE 1-9
Content determination results of the stability study for the porphyrin
iron-Kollidon ®VA 64 solid dispersion (sealed)
Test period
Test
0
1
3
7
14
35
Samples
conditions
day
day
days
days
days
days
API
25° C.
100.9%
99.5%
102.0%
100.5%
98.9%
102.2%
Formula 1-2
60% RH
100.5%
98.8%
101.6%
99.6%
97.6%
100.8%
API
40° C.
100.9%
99.6%
102.7%
100.8%
99.2%
102.7%
Formula 1-2
75% RH
100.5%
98.8%
100.4%
98.2%
98.1%
96.6%
[0081] As can be seen from Table 1-8 and Table 1-9, for the API porphyrin iron and the porphyrin iron-Kollidon®VA 64 solid dispersion, after being placed at 25° C. 60% RH and 40° C. 75% RH for 35 days, the contents of porphyrin iron were within the confidence interval of 96%-104% of the analysis method established for the content determination for the solid dispersions in Example 1-3. The slightly lower labelled amounts of the drug were due to about 3% water contained in the solid dispersion. The test results indicated that porphyrin iron was very stable in the porphyrin iron-Kollidon®VA 64 solid dispersion.
[0082] Preparation of Porphyrin Iron-Soluplus® Solid Dispersions
Example 2-1
Preparation of Porphyrin Iron-Soluplus® Solid Dispersion
[0083] Formula: The specific composition of each solid dispersion formula was shown in Table 2-1.
[0000]
TABLE 2-1
Specific composition of each solid dispersion formula
Names of raw materials and
Amounts of raw materials and adjuvants (g)
adjuvants
Formula 2-1
Formula 2-2
Formula 2-3
porphyrin iron
35
30
20
Soluplus ®
35
90
200
[0084] Preparation process: Porphyrin iron and the carrier material in the amounts shown in the formulae in Table 2-1 were added to a mixer separately and mixed homogenously. Alternatively, porphyrin iron and the carrier material in the amounts shown in the formulae in Table 2-1 were fed into a loading hopper of a co-rotating twin screw extruder (Omicron 12, Steer Engineering Private Limited, India). The melting temperature in the screw extruder was controlled at about 120° C. to about 180° C., and the rotation speed of the screw was about 50 to about 500 rpm. The extruded mixtures were cooled, pulverized, and sieved, to obtain the solid dispersions.
[0085] Evaluation on the Physical And Chemical Properties of the Porphyrin Iron-Soluplus® Solid Dispersions
Test Example 2-2
Determination of the Content of Porphyrin Iron in the Solid Dispersions
[0086] Sample preparation: an appropriate amount of the solid dispersion of each formula was weighted and dissolved in 0.1N aqueous NaOH solution, to prepare a test sample with a porphyrin iron concentration of about 50 μg/ml. Analysis was conducted by a HPLC method. The analysis method for the content determination was the same as that for the content determination for the solid dispersions in Example 1-3. The results were shown in Table 2-2.
[0000]
TABLE 2-2
Content determination results for each solid dispersion formula
Formula
Formula 2-1
Formula 2-2
Formula 2-3
Labelled
94.7
92.0
93.5
amount (%)
[0087] As can be seen from Table 2-2, the labelled amounts of the drug for all formulae after being extruded were above 90%, indicating that the hot melt extrusion process had little influence on the stability of the drug. The slightly lower labelled amounts of the drug were due to about 3%-6% of water contained in the solid dispersions.
Test Example 2-3
Determination of the Apparent Solubility of the Solid Dispersions
[0088] Sample preparation: Excess amounts of the porphyrin iron solid dispersions of various formulae and physical mixtures of porphyrin iron and the carrier material (prepared by weighting the active pharmaceutical ingredient and the carrier adjuvant in the amounts shown in the formulae and simply mixing them) were weighted separately, and placed in appropriate containers, a phosphate buffer solution having a pH of 6.8 and a volume of about 2/3 of the volume of the container was added, and then it was placed in a shaking table at 37° C. and was shaken for 24 h. The resultant solution was filtered through a 0.45 μm filter membrane, and then the filtrate was collected, further diluted with an appropriate amount of 0.1N NaOH, and analyzed by HPLC after vortex mixing. The analysis method was the same as the method for the content determination for the solid dispersions in Example 1-3. The determination results were shown in Table 2-3.
[0000]
TABLE 2-3
Solubility determination results for each solid dispersion formula
Formula
Formula
Formula
Formula
2-1
2-2
2-3
API
A 1)
B 2)
A
B
A
B
Solubility
<0.2
<0.6
33.8
1.3
28.1
<0.6
69.7
(μg/ml)
Solubility
— 3)
>169
>140
>348
ratio (solid
dispersion/API)
Solubility
—
>56
22
>116
ratio (solid
dispersion/
physical
mixture)
1) “A” represents a physical mixture (not a solid dispersion of the present invention) with the same composition as sample B.
2) “B” represents a solid dispersion of the present invention.
3) “—” means that there is no determined value.
[0089] As can be seen from the solubility determination results in Table 2-3 and FIG. 5 , all Soluplus® solid dispersions of various formulae prepared by a hot melt extrusion process had significant solubilizing effects on porphyrin iron. As can be seen from the results obtained from the single-variable design of experiment (DOE), there is a certain relationship between the weight ratio of the carrier to porphyrin iron in the solid dispersions and the solubility of porphyrin iron in the solid dispersions. As shown in FIG. 5 , the solubility of porphyrin iron in the solid dispersions was increased with the increase of the weight ratio of the carrier to porphyrin iron. Soluplus® had fairly good solubilizing effects on porphyrin iron. In FIG. 6 , when being dispersed in the buffer at pH 6.8 for 3 min, all the prepared solid dispersions of various formulae had colors significantly deeper than those of the physical mixtures, indicating that the solid dispersions, which were prepared with Soluplus® and in which porphyrin iron was in the state of being dispersed at molecular level, could largely increase the solubility of porphyrin iron.
Test Example 2-4
In Vitro Dissolution Tests for the Solid Dispersions
[0090] The conditions for the dissolution tests were the same as the dissolution tests of the solid dispersions in Example 1-5.
[0091] The analysis method for sample dissolution was the same as that for the content determination for the solid dispersions in Example 1-3. The results were shown in Table 2-4 and Table 2-5.
[0000]
TABLE 2-4
Results of the dissolution tests for the solid dispersions
of various formulae in the dissolution medium at pH 1.2
Concentrations of dissolved API
at various time points (μg/ml)
Test
5
10
15
30
45
60
samples
min
min
min
min
min
min
Formula 2-1
2.4
2.3
1.89
2.6
3.9
2.9
Formula 2-2
6.6
12.2
6.8
5.2
6.6
3.4
Formula 2-3
37.0
34.1
36.0
36.5
34.9
36.5
[0000]
TABLE 2-5
Results of the dissolution tests for the solid dispersions
of various formulae in the dissolution medium at pH 6.8
Concentrations of dissolved API
at various time points (μg/ml)
Test
15
30
45
60
120
180
samples
min
min
min
min
min
min
Formula 2-1
1.8
2.7
3.0
2.5
3.4
2.8
Formula 2-2
4.2
3.3
3.1
3.2
1.8
2.3
Formula 2-3
1.9
2.3
1.9
2.2
2.2
2.2
[0092] As can be seen from Table 2-4 and Table 2-5, each formula containing Soluplus® can increase the concentration of dissolved porphyrin iron and the dissolution rate of porphyrin iron.
[0093] Preparation of Porphyrin Iron-HPMCAS Solid Dispersions
Example 3-1
Preparation of Porphyrin Iron-HPMCAS (AQOAT AS-M) Solid Dispersions
[0094] Formula: The specific composition of each solid dispersion formula was shown in Table 3-1.
[0000]
TABLE 3-1
Specific composition of each solid dispersion formula
Names of raw materials
Amounts of raw materials and adjuvants (g)
and adjuvants
Formula 3-1
Formula 3-2
Formula 3-3
porphyrin iron
35
50
20
HPMCAS
35
150
200
[0095] Preparation process: Porphyrin iron and the carrier material in the amounts shown in the formulae in Table 3-1 were added to a mixer separately and mixed homogenously. Alternatively, porphyrin iron and the carrier material in the amounts shown in the formulae in Table 3-1 were fed into a loading hopper of a co-rotating twin screw extruder (Omicron 12, Steer Engineering Private Limited, India). The melting temperature in the screw extruder was controlled at about 120° C. to about 180° C., and the rotation speed of the screw was about 50 to about 500 rpm. The extruded mixtures were cooled, pulverized, and sieved, to obtain the solid dispersions.
[0096] Evaluation on the Physical and Chemical Properties of the Porphyrin Iron-HPMCAS Solid Dispersions
Test Example 3-2
Determination of the Content of Porphyrin Iron in the Solid Dispersions
[0097] Sample preparation: an appropriate amount of the solid dispersion of each formula was weighted, and dissolved in 0.1N aqueous NaOH solution, to prepare a test sample with a porphyrin iron concentration of about 50 μg/ml. Analysis was conducted by a HPLC method. The analysis method for the content determination was the same as that for the content determination for the solid dispersions in Example 1-3. The results were shown in Table 3-2.
[0000]
TABLE 3-2
Content determination results for each solid dispersion formula
Formula
Formula 3-1
Formula 3-2
Formula 3-3
Labelled
95.6
85.5
91.7
amount (%)
[0098] As can be seen from Table 3-2, the labelled amounts of the drug for all formulae after being extruded were above 85%, indicating that the hot melt extrusion process had little influence on the stability of the drug. The slightly lower labelled amounts of the drug were due to about 3%-6% of water contained in the solid dispersions.
Test Example 3-3
Determination of the Apparent Solubility of the Solid Dispersions
[0099] Sample preparation: Excess amounts of the porphyrin iron solid dispersions of various formulae and the physical mixture of porphyrin iron and the carrier material (prepared by weighting the active pharmaceutical ingredient and the carrier adjuvant in the amounts shown in the formulae and simply mixing them) were weighted separately, and placed in appropriate containers, a phosphate buffer solution having a pH of 6.8 and a volume of about 2/3 of the volume of the container was added, and then it was placed in a shaking table at 37° C. and was shaken for 24h. The resultant solution was filtered through a 0.45 μm filter membrane, and then the filtrate was collected, further diluted with an appropriate amount of 0.1N NaOH, and analyzed by HPLC after vortex mixing. The analysis method was the same as the method for the content determination for the solid dispersions in Example 1-3. The determination results were shown in Table 3-3.
[0000]
TABLE 3-3
Solubility determination results for each solid dispersion formula
Formula
Formula
Formula
Formula
3-1
3-2
3-3
API
A 1)
B 2)
A
B
A
B
Solubility
<0.2
<0.2
71.1
<0.2
66.0
<0.2
54.0
(μg/ml)
Solubility
— 3)
>355
>330
>270
ratio (solid
dispersion/API)
Solubility
—
>355
>330
>270
ratio (solid
dispersion/
physical
mixture)
1) “A” represents a physical mixture (not a solid dispersion of the present invention)
with the same composition as sample B.
2) “B” represents a solid dispersion of the present invention.
3) “—” means that there is no determined value.
[0100] As can be seen from the solubility determination results in Table 3-3 and FIG. 7 , all HPMCAS solid dispersions of various formulae prepared by the hot melt extrusion process had significant solubilizing effects on porphyrin iron. As can be seen from the results obtained from the single-variable design of experiment (DOE), there is a certain relationship between the weight ratio of the carrier to porphyrin iron in the solid dispersions and the solubility of porphyrin iron in the solid dispersions. As shown in FIG. 7 , the solubility of porphyrin iron in the solid dispersions was slightly decreased with the increase of the weight ratio of the carrier to porphyrin iron. In FIG. 8 , when being dispersed in the buffer at pH 6.8 for 3 min, all the prepared solid dispersions of various formulae had colors significantly deeper than those of the physical mixtures, indicating that the solid dispersion technique could largely increase the solubility of porphyrin iron.
Test Example 3-4
In Vitro Dissolution Tests of the Solid Dispersions
[0101] The conditions for the dissolution tests were the same as the dissolution tests of the solid dispersions in Example 1-5.
[0102] The analysis method for sample dissolution was the same as that for the content determination for the solid dispersions in Example 1-3. The results were shown in Table 3-4 and Table 3-5.
[0000]
TABLE 3-4
Results of the dissolution tests for the solid dispersions
of various formulae in the dissolution medium at pH 1.2
Concentrations of dissolved API
at various time points (μg/ml)
Test
5
10
15
30
45
60
samples
min
min
min
min
min
min
Formula 3-1
<0.3
<0.3
<0.3
<0.3
<0.3
<0.3
Formula 3-2
1.0
1.1
1.1
1.1
1.2
1.2
Formula 3-3
<0.3
<0.3
<0.3
<0.3
<0.3
<0.3
[0000]
TABLE 3-5
Results of the dissolution tests for the solid dispersions
of various formulae in the dissolution medium at pH 6.8
Concentrations of dissolved API
at various time points (μg/ml)
Test
15
30
45
60
120
180
samples
min
min
min
min
min
min
Formula 3-1
44.7
44.3
42.4
43.6
43.3
44.4
Formula 3-2
44.7
49.5
50.7
50.6
25.8
26.1
Formula 3-3
47.9
49.2
48.1
47.3
48.5
49.0
[0103] As can be seen from Table 3-4 and Table 3-5, the HPMCAS solid dispersion of each formula can increase the concentration of dissolved porphyrin iron and the dissolution rate of porphyrin iron in the medium at pH 6.8. The dissolved amounts in the medium at pH 1.2 were very few, since HPMCAS was an enteric material.
Example 4
Clinical Tests on the Mouthfeel and Gastrointestinal Tract Irritation of Porphyrin Iron Solid Dispersions
[0104] In order to evaluate the mouthfeel and gastrointestinal tract irritation of porphyrin iron solid dispersions, 6 healthy volunteers were enrolled in tests on the mouthfeel and gastrointestinal tract irritation for the samples such as Formula 1-1, Formula 1-2, Formula 1-4, Formula 2-2, Formula 3-2 and the API of porphyrin iron. The test results were summarized in Table 4-1.
[0105] Test procedure for mouthfeel and gastrointestinal tract irritation: 6 healthy volunteers, who had no bad habits such as smoking and drinking and had certain sensory evaluation practice, were enrolled. Each volunteer took a sample into his or her mouth and ingested it with warm water at 10:00 am every day, and recorded his or her actual feeling after 20 minutes. The tests were carried out for 6 consecutive days, and each volunteer took all samples one by one.
[0000]
TABLE 4-1
Results of the mouthfeel and gastrointestinal tract irritation test for the
porphyrin iron solid dispersions
Feeling of
Feeling of
Samples
Mouthfeel
stomach burning
nausea
Formula 1-1
Heavy bitterness, no other
Slight stomach
Slight nausea
(porphyrin iron:Kollidon ®
undesirable tastes
burning feeling
feeling
VA 64 = 1:1)
Formula 1-2
Bitterness, heavy aftertaste,
No obvious
No obvious
(porphyrin iron:Kollidon ®
no other undesirable tastes
stomach burning
nausea feeling
VA 64 = 1:3)
feeling
Formula 1-4
Agglomerating in mouth,
No stomach
No nausea
(porphyrin iron:Kollidon ®
slight bitterness, no other
burning feeling
feeling
VA
undesirable tastes
64 = 1:10)
Formula 2-2
Pleasant taste, no obvious
No stomach
No nausea
(porphyrin iron:Soluplus ® =
undesirable tastes, good
burning feeling
feeling
1:3)
palatability
Formula 3-2
Obvious granular sensation
No obvious
No obvious
(porphyrin iron:HPMCAS =
in mouth, no obvious
stomach burning
nausea feeling
1:3)
undesirable tastes
feeling
API
Heavy blood smell,
Obvious
Obvious nausea
undesirable tastes
stomach burning
feeling
feeling
[0106] The results in Table 4-1 showed that by preparing porphyrin iron and Kollidon®VA 64, Soluplus® and HPMCAS into solid dispersions, the blood smell and undesirable tastes of porphyrin iron can be effectively masked and removed, and the stomach burning feeling and nausea feeling of porphyrin iron can be reduced significantly or even avoided, such that the compliance of patients can be improved.
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Disclosed are a ferroporphyrin solid dispersion, preparation method therefor and a pharmaceutical composition comprising the solid dispersion, wherein the weight ratio of ferroporphyrin to the carrier material in the dispersion is 1:1-1:10. The solid dispersion of the present invention masks the undesirable taste of ferroporphyrin, ameliorates irritation thereof to the digestive tract, and at the same time increases the solubility thereof and improves the bioavailability thereof.
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BACKGROUND OF THE INVENTION
This invention relates to automotive warning lights. Traffic laws and regulations dictate that various lights be provided in an automobile for warning or notifying drivers in other cars or pedestrians of the condition of the automobile which is running. For prevention of the rear-end collisions it is preferable that the driver of a trailing car be properly notified of the condition of a preceding car so as to apply a suitable braking operation. At the present time there is known only a stop light for warning the driver of a trailing car of a braking action. Thus, there is not any means for warning or notifying the driver of the trailing cars of various stages of engine braking operations of the preceding car.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide automotive lights or lamps for warning the drivers of trailing cars of an engine braking operation of a preceding vehicle.
It is another object of the present invention to provide automotive lights or lamps for indicating to the drivers of trailing cars the occurrence of accelerating operations of a preceding vehicle by a plurality of green lights or lamps and of engine braking operations of the preceding vehicle by a plurality of amber lights or lamps.
BRIEF DESCRIPTION OF THE DRAWINGS
There are other objects and features of the present invention which will be apparent from a reading of the following part of the specification in conjunction with the accompanying drawings which indicate a preferred embodiment of the present invention, and in which:
FIG. 1 is a schematic view showing manifold pressure detecting means and accelerator pedal movement detecting means according to the present invention;
FIG. 2 is a schematic diagram of an electric circuit according to the invention;
FIG. 3 is a detailed view of a portion of the electric circuit of FIG. 2; and
FIG. 4 is a perspective rear view of an automobile.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, intake air is introduced through an air cleaner 2, a carburetor 3, and an intake pipe 4 into a cylinder 1 of an engine of an automobile. A shaft 5 of a throttle valve of the carburetor is coupled through a transmission 6 such as a cable or a rod to an accelerator pedal 7 for the purpose of controlling the engine by adjusting the opening of the throttle valve in the carburetor 3. According to the present invention, a sensor 8 is provided to detect the position of the accelerator pedal being depressed or the opening of the throttle valve. The sensor 8 is shown to detect the movement of the transmission 6 in the drawing, but it may be positioned to detect the angular movement of the accelerator pedal shaft or the shaft 5 of the throttle valve.
An intake pressure or manifold pressure sensor 14 is coupled to the carburetor 3 at a position downstream of the throttle valve thereof or to an intake manifold in a suitable position to actuate a switch 15 at a predetermined pressure level, for instance, at a pressure level of 0.2 kg/cm 2 absolute. The sensor 14 may be of any suitable type, such as, a spring loaded diaphragm or piston type or the like. Further, the sensor 14 may be of a known type utilizing a pressure gauge mechanism.
In FIG. 2 showing an outline of an electric system, a lamp assembly 16 is mounted at the rear end portion of the automobile. In the drawing, only one lamp assembly is shown, although it is preferable that a pair of lamp assemblies be provided on the right and left sides of the rear end of the automobile as shown in FIG. 4. The lamp assembly 16 consists of five portions 16a to 16e which are adapted to selectively indicate green and amber lights. To this end, green lights and amber lights may be provided in respective portions, or alternately, there may be used a combination of yellow or bright yellow glass and blue and red lamps. An electric power source 17 such as a battery and a generator of the electric system of the vehicle supplies electric power to the lamp assembly 16.
A green light circuit 19 acts to light the green lights under the control of the sensor 8, when switches 18 and 15 are turned on. An amber light circuit 20 acts to light the amber light under the control of sensor 8 when the switch 18 is on. However, when the green circuit 19 is energized, an electromagnetic switch 21 is turned off, so that the amber light is dimmed by a resistor 22. When the green light circuit is not energized, the switch 21 is turned on so that the intensity of the orange light is increased.
As shown in FIG. 3, the sensor 8 consists of contact portions 9a - 9e and 10a - 10e and contacts 11 which cooperate with the contact portions. The contact portion 9 and 10 (the numerals generally represent respective contact portions 9a - 9e and 10a - 10e) as well as the contacts 11 may be relatively moved in the direction of arrow A in response to the position of the accelerator pedal being depressed or the opening of the throttle valve. In FIG. 3, the contacts 11 assumes the position of the solid lines at zero opening of the throttle valve or in the normal inactuated position of the accelerator pedal, and assumes the broken line position at the full open position of the throttle valve or the fully depressed position of the accelerator pedal. The contact portions 9a - 9e are connected respectively to green lights 16a' - 16e', and the contact portions 10a - 10e to amber lights 16a" - 16e" respectively. Rectifiers 12 are disposed in these connections as shown, so that when the contacts 11 cooperate with the contact portions 9a and 10b the green light 16a' and amber lights 16b" to 16e" are lit, and when the contacts 11 cooperate with the contact portions 9b and 10c the green lights 16a' and 16b' as well as amber lights 16c", 16d" and 16e" are lit. In FIG. 3, only the contact portion 10a contacts the contacts 11 at the zero opening position of the throttle valve, and a portion of contact position 9 opposite to the contact portion 10a is provided with a spacer S.
With the aforesaid arrangement, when the switch 15 is in its on position, i.e., when the intake pressure is over a predetermined value, the relative position of depression of the accelerator pedal is numerically indicated by the number of green lights 16a' to 16e' which are lit so that the drivers of trailing cars may have an indication of the speed of the vehicle. In this respect, amber lights in another partition in which the green lights are not lit are lit with reduced intensity, thereby fascilitating the recognition of the number of green lights being lit.
In an engine braking condition, the intake pressure is lowered below the predetermined level and the switch 15 is turned off, the green light circuit is disconnected and the green lights are extinguished. In this respect, for instance, when the accelerator pedal 7 is released from the fully depressed position, five orange lights will be lit at increased intensity, which notifies the drivers of the trailing cars that a severe engine braking operation has been applied on the preceding car and enables the trailing drivers to take suitable braking action sooner than previously possible. When the accelerating operation is applied immediately following the engine braking operation, the amber lights will be dimmed and a number of green lights corresponding to the amount of depression of the accelerator pedal will be lit. Thus, end collision accidents may completely be prevented according to the present invention, and safe and comfortable driving may be insured.
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An automotive light system for warning or notifying the drivers of the trailing cars includes green lamps the number of which being lit indicates the relative position of depression of the accelerator pedal, amber lamps for indicating an engine braking operation, and an intake pressure sensor for detecting the intake pressure of an engine of the automobile to extinguish the green lamps and to light the amber lamps when the intake pressure decreases below a predetermined level upon an engine braking operation.
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FIELD OF THE INVENTION
[0001] The present invention relates to a polarity reversal driving method for liquid crystal display panel, and an apparatus thereof.
BACKGROUND
[0002] With a development of economy and technology, a display, especially a liquid crystal flat display apparatus, is more popular in an application of a computer, a mobile device, a multimedia and a TV display, etc. In order to reduce a picture flicker and crosstalk caused by direct current afterimage during a driving display process of the liquid crystal and fluctuations in a common voltage arising from a coupling to a common electrode from signal lines, the current driving manners in most of the liquid crystal panels utilize a dot reversal, 2-dot reversal, and a (1+2)-dot reversal as the polarity reversal method. At a time of displaying some special evaluation patterns, the common voltage would not return to a normal value when the next frame starts if a coupling effect to the common electrode by the data signals is large, such that the flicker in the picture or the crosstalk in several initial rows of the picture is serious; also, during a scan process for the same frame, the crosstalk phenomenon in the picture of entire screen is very serious, if the coupling effect to the common electrode by the data signals is large and a polarity reversal frequency among rows is relatively high.
[0003] In FIG. 1 , a) and b) are two display patterns under a driving method of an existing 1+2 dot reversal. In view of a TN normal-white mode, assuming a voltage difference between a sub-pixel electrode and the common electrode in non-shadow region as 0V and that in shadow region as 1V. For a) in FIG. 1 , the voltage Vcom of the common electrode in the current frame is pulled-up, but the Vcom could not return to the normal value at the time of the next frame reversing polarity, which causes an actual voltage difference between the liquid crystal pixel electrode in the next frame and the voltage Vcom being increased, such that a transmittance of LC (liquid crystal) is below a predetermined value and a flicker occurs in two neighbor frames. For b) in FIG. 1 , the date signals in part of the rows pull up the voltage Vcom while the data signals in another part of the rows pull down the voltage Vcom in a same frame, therefore such process for pulling the Vcom from up to down or from down to up would influence an effective voltage input of the pixels in the next row. As illustrated in b) of FIG. 1 , the Vcom is pulled-up at the first row, therefore the voltage difference between the pixel voltage of sub-pixel G and the Vcom is smaller than a predetermined value, while the voltage differences between the pixel voltage of sub-pixels R, B and the Vcom are larger than a predetermined value, respectively, when the pixel signals of the second row is written, which would cause the sub-pixel G is brighter but the sub-pixels R and B are darker, such that a green crosstalk or color offset may be generated. The frequency of pulling the Vcom up/down from respective rows in the same frame is higher, the phenomenon of green crosstalk or color offset is severer.
[0004] In FIG. 2 , A, B, C and D illustrate several common-used display patterns for evaluating the flicker and crosstalk currently. In the existing polarity reversal driving method, there is always one of the patterns which would deteriorate the phenomenon of flicker or crosstalk obviously.
SUMMARY
[0005] Embodiments of the present invention lighten the flicker and crosstalk phenomenon arisen when the liquid crystal display panel is driven to display some special pictures.
[0006] The embodiment of the present invention provides a polarity reversal driving method for liquid crystal display panel, which makes four frames as a polarity reversal driving period and any one of the four frames may be a start frame, and images are scanned and displayed in a forward or backward order of the four frames; wherein during the polarity reversal driving period, the polarity arrangement manners of a first frame and a third frame are same, while their polarities are opposite; the polarity arrangement manners of a second frame and a fourth frame are same, while their polarities are opposite, and the polarity arrangement manner of the first frame is different from that of the second frame.
[0007] In one embodiment, the polarity arrangement manner of each frame is repeated by a period of eight rows, and the sum of polarities in a first unit composed of a first row, a second row, a third row, and a fourth row and those in a second unit composed of a fifth row, a sixth row, a seventh row, and a eighth row is 0 in a same column, and neighbor columns in a same row have opposite polarities.
[0008] In one embodiment, the polarity arrangement manner in the first column of one polarity arrangement period is negative, positive, positive, negative, positive, negative, negative, and positive.
[0009] In one embodiment, the polarity arrangement manner in the first column of one polarity arrangement period is positive, negative, positive, negative, negative, positive, negative, and positive.
[0010] In one embodiment, the polarity arrangement manner in the first column of one polarity arrangement period is negative, positive, positive, negative, positive, positive, negative, and negative.
[0011] In one embodiment, the polarity arrangement manner in the first column of one polarity arrangement period is positive, positive, negative, negative, negative, positive, negative, and positive. The polarity is a polarity with respect to a pixel common electrode voltage.
[0012] The embodiment of the present invention further provides a polarity reversal driving apparatus for the liquid crystal display panel comprising: a timing controller, a signal delay unit, a polarity reversal unit, a signal polarity switching switch and a source driver;
[0013] the signal delay unit is configured to receive a first polarity reversal signal POL 1 and a timing signal clock CPV output from the timing controller so as to generate a second polarity reversal signal POL 2 ;
[0014] the polarity reversal unit is configured to receive the second polarity reversal signal POL 2 output from the signal delay unit so as to generate a third polarity reversal signal POL 3 ;
[0015] the signal polarity switching switch is configured to alternatively switch the second polarity reversal signal POL 2 and the third polarity reversal signal POL 3 according to a high, low level of a first switching pulse and a second switching pulse output from the timing controller, to generate a fourth polarity reversal signal POL 4 and output the same to the source driver, wherein the periods of both the first switching pulse and the second switching pulse are same as the polarity arrangement period, and the fourth polarity reversal signal POL 4 is used for controlling signal output polarities of respective frames during one polarity reversal driving period as scanning;
[0016] the timing controller is configured to output the first polarity reversal signal POL 1 and the timing signal clock CPV, to alternatively output the first switching pulse and the second switching pulse in a unit of frame, and to perform polarity reversal once upon the next outputting, in order to correspond to the generation and output of the fourth polarity reversal signal POL 4 of respective frames in the four frames within the polarity reversal driving period;
[0017] the source driver is configured to output image data signals with positive polarity or negative polarity according to the high level or low level of the fourth polarity reversal signal POL 4 , respectively, when it receives the signal POL 4 .
[0018] In one embodiment, a corresponding manner is that: the second polarity reversal signal POL 2 is selected when both the first switching pulse and the second switching pulse are at a high level; instead, the third polarity reversal signal POL 3 is selected when both the first switching pulse and the second switching pulse are at a low level.
[0019] The embodiment of the present invention further provides another polarity reversal driving apparatus for the liquid crystal display panel comprising: a timing controller, a signal delay unit, a logic operating unit, a first signal polarity switching switch, a second signal polarity switching switch and a source driver;
[0020] the signal delay unit is configured to receive a first polarity reversal signal POL 1 and a timing signal clock CPV output from the timing controller so as to generate a second polarity reversal signal POL 2 ;
[0021] the logic operating unit is configured to receive the second polarity reversal signal POL 2 output from the signal delay unit and the first polarity reversal signal POL 1 output from the timing controller so as to generate a third polarity reversal signal POL 3 ;
[0022] the first signal polarity switching switch is configured to alternatively switch the second polarity reversal signal POL 2 and the first polarity reversal signal POL 1 according to a high, low level of a first switching pulse output from the timing controller, to generate a fourth polarity reversal signal POL 4 and output the same to the source driver, in order to control signal output polarities of the first frame;
[0023] the second signal polarity switching switch is configured to alternatively switch the first polarity reversal signal POL 1 and the third polarity reversal signal POL 3 according to a high, low level of a second switching pulse output from the timing controller, to generate a fifth polarity reversal signal POL 5 and output the same to the source driver, in order to control signal output polarities of the second frame;
[0024] the timing controller is configured to output the first polarity reversal signal POL 1 and the timing signal clock CPV, and to alternatively output the first switching pulse and the second switching pulse in a unit of frame, wherein the periods of the first switching pulse and the second switching pulse are same as the polarity arrangement period;
[0025] the source driver is configured to output image data signals with positive polarity or negative polarity according to the high level or low level of the fourth polarity reversal signal POL 4 and the fifth polarity reversal signal POL 5 , respectively, after it receives the fourth polarity reversal signal POL 4 and the fifth polarity reversal signal POL 5 .
[0026] The embodiments of the present invention lightens the flicker and crosstalk phenomenon arisen when the liquid crystal display panel is driven to display some special pictures by the designed polarity reversal driving method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In FIG. 1 , a) is a schematic view wherein the flickering pattern is displayed by existed polarity reversal driving method, while b) is a schematic view wherein a green crosstalk or color offset is displayed by the existing polarity reversal driving method;
[0028] In FIG. 2 , A, B, C and D are schematic views of common-used patterns for evaluating the flicker and green crosstalk or color offset in the liquid crystal display panel, respectively;
[0029] In FIG. 3 , 3 - a to 3 - d are schematic views illustrating the frame polarity reversal manner of a first implementation of the present invention;
[0030] In FIG. 4 , 4 - a to 4 - d are schematic views illustrating a polarity analysis of data signals in respective frames with respect to the common electrode voltage during one polarity reversal driving period, when an evaluation pattern B is displayed by the first implementation of the present invention;
[0031] In FIG. 5 , 5 - a to 5 - d are schematic views illustrating a polarity analysis of data signals in respective frames with respect to the common electrode voltage during one polarity reversal driving period, when a severest flickering pattern of FIG. 3 - a ) is displayed by the first implementation of the present invention;
[0032] In FIG. 6 , 6 - a to 6 - d are schematic views illustrating a coupling effect analysis of data signals in respective frames with respect to the common electrode voltage during one polarity reversal period, when an evaluation pattern D is displayed by the first implementation of the present invention;
[0033] FIG. 7 is a schematic view illustrating a driving apparatus of the first implementation of the present invention;
[0034] In FIG. 8 , 8 - a , 8 - b , 8 - c and 8 - d are schematic timing charts of data polarity controlling signals generated in the first frame, the second frame, the third frame and the fourth frame during one polarity reversal period, respectively, wherein the driving apparatus as shown in FIG. 7 according to the first implementation of the present invention is applied;
[0035] In FIG. 9 , 9 - a to 9 - d are schematic views illustrating the frame polarity reversal manner of a second implementation of the present invention;
[0036] FIG. 10 is a schematic view illustrating a driving apparatus of the second implementation of the present invention;
[0037] In FIG. 11 , 11 - a , 11 - b , 11 - c and 11 - d are schematic timing charts of data polarity controlling signals generated in the first frame, the second frame, the third frame and the fourth frame during one polarity reversal driving period, respectively, where the driving apparatus as shown in FIG. 10 according to the second implementation of the present invention is applied;
[0038] In FIG. 12 , 12 - a to 12 - d are schematic views illustrating the frame polarity reversal manner of a third implementation of the present invention;
[0039] In FIG. 13 , 13 - a to 13 - d are schematic views illustrating the frame polarity reversal manner of a fourth implementation of the present invention; and
[0040] In FIG. 14 , 14 - a to 14 - d are schematic views illustrating the frame polarity reversal manner of a fifth implementation of the present invention.
[0041] In the drawings, reference numbers 1 , 2 , 3 , 4 and 5 denote one polarity reversal period of the first implementation, the second implementation, the third implementation, the fourth implementation and the fifth implementation of the present invention, respectively; a reference number 11 denotes the polarity arrangement period of the first frame in the first implementation, and reference numbers 111 and 112 denote the first unit and the second unit during the polarity arrangement period of the first frame, respectively, a reference number 12 denotes the polarity arrangement period of the second frame in the first implementation, and reference numbers 121 and 122 denote the first unit and the second unit during the polarity arrangement period of the second frame, respectively; reference numbers 101 , 102 , 103 , 104 and 105 denote the timing controller, the signal delay unit, the polarity reversal unit, the signal polarity switching switch and the source driver of the first implementation; a reference number 21 denotes the polarity arrangement period of the first frame in the second implementation, and reference numbers 211 and 212 denote the first unit and the second unit during the polarity arrangement period of the first frame, respectively, a reference number 22 denotes the polarity arrangement period of the second frame in the second implementation, and reference numbers 221 and 222 denote the first unit and the second unit during the polarity arrangement period of the second frame, respectively; reference numbers 201 , 202 , 206 , 204 - 1 , 204 - 2 and 205 denote the timing controller, the signal delay unit, the logic operating unit, the first signal polarity switching switch, the second signal polarity switching switch and the source driver of the second implementation.
DETAILED DESCRIPTION
[0042] Below detailed implementations of the invention will be described in further details in connection with the accompanying drawings and embodiments. The following embodiments are only used to illustrate the invention, but not intend to limit the scope of the invention.
[0043] First Implementation
[0044] FIGS. 3-8 illustrate the first implementation of the present invention. FIG. 3 illustrates that four frames constitute one polarity reversal driving period (marked as 1) in a process for driving the liquid crystal display panel, that is, FIGS. 3 - a , 3 - b , 3 - c and 3 - d correspond to the polarity arrangement manners in the first frame, the second frame, the third frame and the fourth frame, respectively. Wherein the first frame (FIG. 3 - a ) and the third frame (FIG. 3 - c ) have the same polarity arrangement manners and opposite polarities; the second frame (FIG. 3 - b ) and the fourth frame (FIG. 3 - d ) have the same polarity arrangement manners and opposite polarities; and the polarity arrangement manners in FIG. 3 - a and FIG. 3 - b are different. In the first frame, as shown in FIG. 3 - a , the polarity arrangement manner is repeated in a period of eight rows (marked as 11) in a portrait direction (paralleled to a data signal line), wherein the first row to the fourth row compose a first unit 111 , and the fifth row to the eighth row compose a second unit 112 . For the first unit 111 , the polarity arrangement in a same column (such as a red sub-pixel column R (the first column)) is negative, positive, positive, negative, and for the second unit 112 , the polarity arrangement in a same column (such as a red sub-pixel column R (the first column)) is positive, negative, negative, positive. The polarities of the first unit 111 and the second unit 112 in the same column are summed to zero, while the polarities of neighbor sub-pixels in a same row are opposite. In the second frame, as shown in FIG. 3 - b , the polarity arrangement manner is repeated in a period of eight rows (marked as 12) in a portrait direction (paralleled to the data signal line), wherein the first row to the fourth row compose a first unit 121 , and the fifth row to the eighth row compose a second unit 122 . For the first unit 121 , the polarity arrangement in a same column (such as a red sub-pixel column R (the first column)) is positive, negative, positive, negative, and for the second unit 122 , the polarity arrangement in a same column (such as a red sub-pixel column R (the first column)) is negative, positive, negative, positive. The polarities of the first unit 121 and the second unit 122 in the same column are summed to zero, while the polarities of neighbor sub-pixels in a same row are opposite. The polarity arrangements in the third frame and the fourth frame may be acquired by reversing the polarity arrangements of the first frame and the second frame, respectively.
[0045] FIG. 4 illustrates a coupling effect of the polarities of data signal voltages with respect to the common electrode voltage Vcom on the Vcom, when an existing evaluation pattern B is displayed on the liquid crystal panel utilizing the driving method of the first implementation of the present invention. Assuming that the liquid crystal panel is a TN-type normal-white mode display, a voltage difference between the sub-pixels in non-shadow regions and the common electrode voltage Vcom is 0V, while the voltage difference between the sub-pixels in shadow regions and the common electrode voltage Vcom is 1V. During the scanning display of the first frame, the effects integrated by pulling-up and pulling-down the Vcom from the data signals balance with each other in each of the polarity arrangement periods, and the Vcom does not deviate from the normal level value, so that the driving voltage of the liquid crystal on pixels may not deviate from a set value at a time of scanning in next frame and in turn no flickering phenomenon will occur. Similarly, there are no net pulling effects on the Vcom during the scanning display of the second frame, the third frame and the fourth frame, therefore no flickering would occur in the entire polarity reversal frame period. Furthermore, no flickering phenomenon would occur for other evaluation patterns A, C, D, etc. shown in FIG. 2 . However, in the polarity arrangement manners of existing dot reversal (1 dot), (1+2)-dot reversal and 2-dot reversal, the driving methods thereof are polarity reversal between two neighbor frames, such that there are always data signals in one of the evaluation patterns A, B, C and D shown in FIG. 2 which will generate a large pulling to the common electrode voltage Vcom. If the polarity of data signals in current frame is positive with respect to Vcom, the Vcom is pulled-up badly and the Vcom could not return to the normal set value even after the polarity reversal in the next frame. Thus, an actual writting voltage of the sub-pixel increases, which results in an obvious difference in liquid crystal transmittance between the two neighbor frames and causes a severe flicker. That is to say, the larger the amplitude of polarity difference between data signals of two neighbor frames with respect to the Vcom is, the severer the flicker caused by the coupling is. Table 1 shows the polarity differences between data signals of two neighbor frames with respect to the Vcom during one polarity arrangement period, when the driving method of an embodiment of the present invention (the first implementation) and the existing driving method are used, respectively.
[0000]
TABLE 1
polarity difference between signals
of two neighbor frames with
respect to Vcom during one
Evaluation
polarity arrangement period (absolute value)
Pattern
First Implementation
1 dot
1 + 2 dot
2 dot
Pattern A
0
16
0
0
Pattern B
0
0
16
0
Pattern C
0
0
0
16
Pattern D
0
0
0
0
Max
0
16
16
16
[0046] FIG. 5 illustrates the display evaluation patterns made for the polarity arrangement manner (FIG. 3 - a ) of the first frame in one polarity arrangement driving period of an embodiment of the present invention. In the current frame, a pulling with negative polarity with respect to the common electrode voltage Vcom is generated, an accumulative magnitude effect in one polarity arrangement period is −8V, and an average effect on each of the rows is −1V; when the pattern is scanned and displayed during the second frame, the accumulative magnitude effect on the common electrode voltage Vcom in one polarity arrangement period is 0V, and the average effect on each of the rows is 0V, that is, the Vcom is not pulled during the scan and display of the second frame; as such, the accumulative effect on the common electrode voltage Vcom from the data signals in one polarity arrangement period is 8V and 0V, respectively, when the pattern is scanned and displayed during the third frame and the fourth frame. Therefore, in one polarity reversal driving period, a maximum magnitude of the polarity difference between data signals of two neighbor frames with respect to the Vcom is 8V in one polarity arrangement period, which is half of the severest polarity difference magnitude of 16V in the existing polarity reversal driving method, thus a degree of the flicker decreases.
[0047] FIG. 6 illustrates a schematic view wherein the evaluation pattern D shown in FIG. 2 is displayed by the driving method of an embodiment of the present invention. As illustrated in FIG. 6 , all of change numbers between the positive pulling and the negative pulling on the Vcom by data signals with respect to the Vcom voltage in the first frame, the second frame, the third frame and the fourth frame are 6 during one polarity arrangement period, and the average change number between the positive pulling and the negative pulling in each of the frames is also 6. On the contrary, in the existing reversal driving method, the dot reversal manner causes the severest crosstalk and its change number between the positive pulling and the negative pulling for the Vcom by data signals is 8 during one polarity arrangement period, when the evaluation pattern is displayed in the dot reversal manner; there is always one of the patterns wherein the data signals would result in the change number between the positive pulling and the negative pulling on the Vcom being 8 when the patterns are displayed in other existing reversal driving manners, which is larger than 6 of the embodiment of the present invention, thus the deterioration degree of the crosstalk may be lightened by utilizing the polarity arrangement manner and the driving method of the embodiment of the present invention. Table 2 lists statistical results of the change numbers between the positive pulling and the negative pulling on the Vcom from each of the frames in average in one polarity arrangement period, when the evaluation patterns shown in FIG. 2 are displayed by using the polarity reversal driving method of an embodiment of the present invention and the existing driving technology, respectively.
[0000]
TABLE 2
Average value of the polarity reversal
Evaluation
numbers between two neighbor frames
Pattern
First Implementation
1 dot
1 + 2 dot
2 dot
Pattern A
2
0
4
4
Pattern B
2
4
0
8
Pattern C
6
4
8
0
Pattern D
6
8
4
4
Max
6
8
8
8
[0048] FIG. 7 illustrates a corresponding apparatus for implementing the above driving method of the embodiment of the present invention. The apparatus generates a polarity reversal signal POL 4 and controls the polarities of the image data signal output from the source driver, wherein POL 1 , POL 2 and POL 3 are intermediary signals generated by different function module units in the apparatus and are used for generating the POL 4 . The apparatus comprises five units, that is, a timing controller 101 , a signal delay unit 102 , a polarity reversal unit 103 , a signal polarity switching switch 104 and a source driver 105 . The signal delay unit 102 receives a first polarity reversal signal POL 1 and a timing signal clock CPV output from the timing controller 101 so as to generate a second polarity reversal signal POL 2 ; the polarity reversal unit 103 receives the second polarity reversal signal POL 2 output from the signal delay unit 102 so as to generate a third polarity reversal signal POL 3 ; the signal polarity switching switch 104 alternatively switches the second polarity reversal signal POL 2 and the third polarity reversal signal POL 3 according to high, low levels of a switching pulse 1 and a switching pulse 2 output from the timing controller 101 , to generate a fourth polarity reversal signal POL 4 and outputs the same to the source driver 105 ; the source driver 105 outputs image data signals with positive polarity or negative polarity according to the high level or low level of the fourth polarity reversal signal POL 4 , respectively, after receiving the POL 4 ; wherein the periods of both the switching pulse 1 and the switching pulse 2 are same as one polarity arrangement period, and the timing controller alternatively outputs the switching pulse 1 and the switching pulse 2 in a unit of frame, and performs polarity reversal upon next outputting, in order to correspond to the generation and output of the fourth polarity reversal signal POL 4 of respective frames in the four frames within the polarity reversal driving period.
[0049] FIG. 8 , 8 - a , 8 - b , 8 - c and 8 - d show the schematic timing charts of the periodic polarity reversal control signal POL 4 generated in the first frame, the second frame, the third frame and the fourth frame during one polarity reversal driving period according to the above embodiment of the present invention. During one polarity arrangement period of the first frame, as illustrated in FIG. 8 - a , the second polarity reversal signal POL 2 is delayed the first polarity reversal signal POL 1 by a row scan clock period, the third polarity reversal signal POL 3 and the second polarity reversal signal POL 2 have the same waveforms but opposite polarities, the signal polarity switching switch 104 selects the second polarity reversal signal POL 2 for outputting when the output of the switching pulse 1 is at a high level and selects the third polarity reversal signal POL 3 for outputting when the output of the switching pulse 1 is at a low level so as to generate the fourth polarity reversal signal POL 4 and control the polarities in the first frame, and the switching pulse 2 is no output until now. During the second frame, as illustrated in FIG. 8 - b , the first polarity reversal signal POL 1 output from the timing controller 101 is reversed in polarity, the switching pulse 2 is output but the switching pulse 1 is not output, the signal polarity switching switch 104 selects the second polarity reversal signal POL 2 for outputting when the output of the switching pulse 2 is at a high level and selects the third polarity reversal signal POL 3 for outputting when the output of the switching pulse 2 is at a low level so as to generate the fourth polarity reversal control signal POL 4 of this frame. During the third frame, the first polarity reversal signal POL 1 output from the timing controller 101 is reversed in polarity, the switching pulse 1 which is reversed with respect to that in the first frame is output and the switching pulse 2 is not output. The signal polarity switching switch 104 selects the second polarity reversal signal POL 2 for outputting when the switching pulse 1 is at a high level and selects the third polarity reversal signal POL 3 for outputting when the switching pulse 1 is at a low level so as to generate the polarity reversal control signal POL 4 of the third frame. During the fourth frame, the first polarity reversal signal POL 1 output from the timing controller 101 is reversed in polarity, the switching pulse 2 which is reversed with respect to that in the second frame is output and the switching pulse 1 is not output. The signal polarity switching switch 104 selects the second polarity reversal signal POL 2 for outputting when the switching pulse 2 is at a high level and selects the third polarity reversal signal POL 3 for outputting when the switching pulse 2 is at a low level so as to generate the polarity reversal control signal POL 4 of the fourth frame. The same process is repeated when the next polarity reversal driving period starts, so that the polarity reversal driving method of the embodiment of the present invention is implemented.
[0050] For the driving apparatus illustrated in FIG. 7 , the timing controller 101 , the signal delay unit 102 , the polarity reversal unit 103 , and the signal polarity switching switch 104 may be integrated into one or more Integrated Circuits, or their respective functions may be integrated into the timing controller according to the timing shown in FIG. 8 and the polarity reversal control signal POL 4 is output directly.
[0051] Second Implementation
[0052] The second implementation of the present invention will be described by referring FIG. 9 , Table 3, Table 4, FIG. 10 and FIG. 11 below. As illustrated in FIG. 9 , one polarity reversal driving period (marked as 2) is composed of four frames, and the periodic polarity arrangement manners in the first frame, the second frame, the third frame and the fourth frame correspond to FIGS. 9 - a , 9 - b , 9 - c and 9 - d , respectively, wherein any one of the four frames may be a start frame of the polarity reversal driving period. In FIG. 9 - a , the polarity arrangement is repeated in a period of eight rows (marked as 21) in a portrait direction (paralleled to a data signal line), wherein the first row to the fourth row compose a first unit 211 , and the fifth row to the eighth row compose a second unit 212 . For the first unit 211 , the polarity arrangement in a same column (such as a red sub-pixel column R) is negative, positive, positive, negative, and for the second unit 212 , the polarity arrangement in a same column (such as a red sub-pixel column R) is positive, positive, negative, negative. The polarities of the first unit 211 and the second unit 212 in the same column are summed to zero, while the polarities of neighbor sub-pixels in a same row are opposite. The second frame corresponds to the polarity arrangement manner in FIG. 9 - b , and the polarity arrangement is repeated in a period of eight rows (marked as 22) in a portrait direction (paralleled to the data signal line), wherein the first row to the fourth row compose a first unit 221 , and the fifth row to the eighth row compose a second unit 222 . For the first unit 221 , the polarity arrangement in a same column (such as a red sub-pixel column R) is positive, positive, negative, negative, and for the second unit 222 , the polarity arrangement in a same column (such as a red sub-pixel column R) is negative, positive, negative, positive. The polarities of the first unit 221 and the second unit 222 in the same column are summed to zero, while the polarities of neighbor sub-pixels in a same row are opposite. The polarity arrangement manners corresponding to the third frame and the fourth frame are illustrated in FIG. 9 - c and FIG. 9 - d , which are obtained by reversing the polarities in FIG. 9 - a and FIG. 9 - b , respectively. Table 3 lists polarity accumulative magnitude differences between the data signals of two neighbor frames with respect to Vcom during one polarity arrangement period, when the common-used evaluation patterns A, B, C and D are displayed by the second implementation of the present invention and by the existing driving method. When the driving method of the embodiment of the present invention is used, a maximum difference of the polarity accumulative magnitudes between data signals of two neighbor frames with respect to the Vcom is 8V during one polarity arrangement period, while the maximum difference is 16V when the polarity reversal driving method of the prior art is used, thus the driving method of the embodiment of the present invention reduces the degree of coupling effect of the current frame on Vcom upon signal writing of the next frame, lightens a brightness disparity between the two neighbor frames, so that the deterioration degree of the flicker is lightened.
[0000]
TABLE 3
polarity difference between two neighbor
frames with respect to Vcom during
Evalution
one polarity arrangement period (absolute value)
Pattern
The Second Implementation
1 dot
1 + 2 dot
2 dot
Pattern A
4
16
0
0
Pattern B
4
0
16
0
Pattern C
8
0
0
16
Pattern D
0
0
0
0
Max
8
16
16
16
[0000]
TABLE 4
average value of the polarity reversal
Evaluation
numbers between two neighbor frames
Pattern
The Second Implementation
1 dot
1 + 2 dot
2 dot
Pattern A
4
0
4
4
Pattern B
4
4
0
8
Pattern C
4
4
8
0
Pattern D
4
8
4
4
Max
4
8
8
8
[0053] Table 4 illustrates an alternating change numbers averaged in each frame between the pulling-up and the pulling-down for the Vcom due to the coupling of the polarities of the data signals in respective rows with respect to Vcom in one polarity arrangement period, when the common-used evaluation patterns shown in FIG. 2 are displayed by the second implementation of the present invention and the existing driving method. The maximum alternating change number for pulling the Vcom by the respective patterns is 4 as utilizing the driving method of the second implementation of the present invention, while the maximum alternating change number for pulling the Vcom by the respective patterns is 8 as utilizing the existing driving method. Because using the polarity arrangement and driving method of the present invention will reduce the alternating change number for pulling the Vcom due to coupling obviously, the green crosstalk or color offset phenomenon could be lightened effectively.
[0054] FIG. 10 illustrates a schematic view of a driving apparatus for implementing the second implementation of the present invention, and the apparatus generates two polarity reversal control signals POL 4 and POL 5 , wherein the POL 4 controls the polarities of the image data signals in the first frame and the third frame during one polarity reversal driving period, while the POL 5 controls the polarities of the image data signals in the second frame and the fourth frame, wherein POL 1 , POL 2 and POL 3 are intermediary signals generated by different function module units in the apparatus and are used for generating the POL 4 and POL 5 . The apparatus comprises a timing controller 201 , a signal delay unit 202 , a logic operating unit 206 , a first signal polarity switching switch 204 - 1 , a second signal polarity switching switch 204 - 2 and a source driver 205 . The signal delay unit 201 receives a first polarity reversal signal POL 1 and a timing signal clock CPV output from the timing controller 201 so as to generate a second polarity reversal signal POL 2 . The logic operating unit 206 receives the second polarity reversal signal POL 2 output from the signal delay unit 202 and the first polarity reversal signal POL 1 output from the timing controller 201 so as to generate a third polarity reversal signal POL 3 . The first signal polarity switching switch 204 - 1 alternatively switches the second polarity reversal signal POL 2 and the first polarity reversal signal POL 1 according to a high, low level of a switching pulse 1 output from the timing controller 201 , generates a fourth polarity reversal signal POL 4 and outputs the same to the source driver 205 , in order to control signal output polarities of the first frame. The second signal polarity switching switch 204 - 2 alternatively switches the first polarity reversal signal POL 1 and the third polarity reversal signal POL 3 according to a high, low level of a switching pulse 2 output from the timing controller 201 , generates the fifth polarity reversal signal POL 5 and outputs the same to the source driver 205 , in order to control signal output polarities of the second frame. The fourth polarity reversal signal POL 4 and the fifth polarity reversal signal POL 5 control signal output polarities of the third frame and the fourth frame, respectively, when the first polarity reversal signal POL 1 output from the timing controller 201 is reversed in polarity. The timing controller 201 alternatively outputs the switching pulse 1 and the switching pulse 2 in a unit of frame, wherein the periods of the switching pulse 1 and the switching pulse 2 are the same as one polarity arrangement period.
[0055] FIGS. 11 - a , 11 - b , 11 - c and 11 - d illustrate, respectively, schematic timing charts of the periodic polarity reversal control signals POL 4 and POL 5 generated in the first frame, the second frame, the third frame and the fourth frame during one polarity reversal driving period according to the second implementation of the present invention. During the scan display of the first frame, as illustrated in FIG. 11 - a , the timing controller 201 outputs the switching pulse signal 1 but does not outputs the switching pulse signal 2 , and the first signal polarity switching switch 204 - 1 selects the second polarity reversal signal POL 2 when the switching pulse signal 1 is at a high level and selects the first polarity reversal signal POL 1 when the switching pulse signal 1 is at a low level so as to generate the fourth polarity reversal signal POL 4 for outputting to the source driver 205 and control the signal output polarities in the first frame. During the scan display of the second frame, as illustrated in FIG. 11 - b , the timing controller 201 outputs the switching pulse signal 2 and the first polarity reversal signal POL 1 which is not in polarity reversed with respect to that in the first frame, but does not output the switching pulse signal 1 . The second signal polarity switching switch 204 - 2 selects the third polarity reversal signal POL 3 when the switching pulse signal 2 is at a high level and selects the first polarity reversal signal POL 1 when the switching pulse signal 2 is at a low level so as to generate the fifth polarity reversal signal POL 5 for outputting to the source driver 205 and control the signal output polarities in the second frame. During the scan display of the third frame, as illustrated in FIG. 11 - c , the timing controller 201 outputs the switching pulse signal 1 and the first polarity reversal signal POL 1 which is in polarity reversed with respect to that in the first frame, but does not output the switching pulse signal 2 . The first signal polarity switching switch 204 - 1 selects the second polarity reversal signal POL 2 when the switching pulse signal 1 is at a high level and selects the first polarity reversal signal POL 1 when the switching pulse signal 1 is at a low level so as to generate the fourth polarity reversal signal POL 4 for outputting to the source driver 205 and control the signal output polarities in the third frame. During the scan display of the fourth frame, as illustrated in FIG. 11 - d , the timing controller 201 outputs the switching pulse signal 2 and the first polarity reversal signal POL 1 which is in polarity reversed with respect to that in the first frame, but does not output the switching pulse signal 1 . The second signal polarity switching switch 204 - 2 selects the third polarity reversal signal POL 3 when the switching pulse signal 2 is at a high level and selects the first polarity reversal signal POL 1 when the switching pulse signal 2 is at a low level so as to generate the fifth polarity reversal signal POL 5 for outputting to the source driver 205 and control the signal output polarities in the fourth frame. The same process is repeated when the next polarity reversal period starts.
[0056] For the driving apparatus illustrated in FIG. 10 , the timing controller 201 , the signal delay unit 202 , the logic operating unit 206 , the first signal polarity switching switch 204 - 1 and the second signal polarity switching switch 204 - 2 may be integrated into one or more Integrated Circuits, or their respective functions may be integrated into the timing controller according to the timing shown in FIG. 11 and the polarity reversal control signals POL 4 and POL 5 are output directly.
[0057] Third Implementation-Fifth Implementation
[0058] FIG. 12 , FIG. 13 and FIG. 14 illustrate the third implementation, the fourth implementation and the fifth implementation according to the polarity reversal driving method of the present invention, wherein the polarity arrangement manners in two neighbor frames are different in any one of the implementations and are not reversed simply with each other as in the prior art. Table 5 lists comparison results, in one polarity arrangement period, of the polarity accumulative magnitude differences between the data signals of two neighbor frames with respect to Vcom, when the common-used evaluation patterns A, B, C and D as shown in FIG. 2 are displayed by the third implementation, the fourth implementation, the fifth implementation of the present invention and by the existing driving method, respectively. When the driving method of the embodiment of the present invention is used, a maximum difference of the polarity accumulative magnitudes between two neighbor frames is only 8V, which is smaller than 16V of the prior art, thus the deterioration degree of the flicker is lightened as displaying the above patterns. Table 6 illustrates an alternating change numbers between the pulling-up and the pulling-down for Vcom averaged in each frame due to the coupling to the Vcom from the polarities of the data signals in respective rows with respect to the Vcom during one polarity arrangement period, when the common-used evaluation patterns are displayed by the third implementation, the fourth implementation, the fifth implementation of the present invention and the existing driving method. The maximum alternating change number for pulling the Vcom by the respective patterns is 6 as utilizing the driving method of the third implementation and the fourth implementation of the present invention, and the maximum alternating change number of the fifth implementation is 4, and all of them are smaller than the maximum alternating change number for pulling the Vcom by the respective patterns as utilizing the existing driving method, which is 8. Because using the polarity arrangement and driving method of the embodiments of present invention will reduce the alternating change number for pulling the Vcom due to the coupling, the green crosstalk or color offset phenomenon could be lightened effectively.
[0000]
TABLE 5
polarity difference between two neighbor frames
with respect to Vcom during one polarity
arrangement period (absolute value)
Third
Evaluation
Imple-
Fourth
Fifth
1
1 + 2
2
Pattern
mentation
Implementation
Implementation
dot
dot
dot
Pattern A
8
8
0
16
0
0
Pattern B
0
8
8
0
16
0
Pattern C
8
0
8
0
0
16
Pattern D
0
0
0
0
0
0
Max
8
8
8
16
16
16
[0000]
TABLE 6
average value of the polarity reversal numbers
between two neighbor frames
Third
Evaluation
Imple-
Fourth
Fifth
1
1 + 2
2
Pattern
mentation
Implementation
Implementation
dot
dot
dot
Pattern A
2
2
4
0
4
4
Pattern B
6
2
4
4
0
8
Pattern C
2
6
4
4
8
0
Pattern D
6
6
4
8
4
4
Max
6
6
4
8
8
8
[0059] For the third implementation, the fourth implementation and the fifth implementation of the present invention, the polarity reversal control signals of respective frames may be obtained by the timing controller alternating the output from every two frames and are in polarity reversed every two frames. Also, the signal output polarities in each of the frames may be controlled by the polarity signal delay unit, signal polarity switching unit and logic operating unit externally attached to the timing controller, just similar to the first implementation or the second implementation, and the details are omitted herein.
[0060] The above are only exemplary embodiments of the present invention, and please note that various changes and modifications may be made in these embodiments without departing from the spirit and scope of the present invention. Therefore, all the variation and alternations will fall into the scope of the present invention, which is defined in the appended claims.
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The invention discloses a polarity reversal driving method for liquid crystal display panel and an apparatus thereof, wherein a polarity reversal driving period comprises four frames and any one of the four frames may be a start frame, and images are scanned and displayed in a forward or backward order of the four frames; wherein during the polarity reversal driving period, the polarity arrangement manners of a first frame and a third frame are same, while their polarities are opposite; the polarity arrangement manners of a second frame and a fourth frame are same, while their polarities are opposite, and the polarity arrangement manner of the first frame is different from that of the second frame. The driving method designed by the present invention can lighten the flicker and crosstalk phenomenon arisen when the liquid crystal display panel displays some pictures.
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BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to drain plugs for bathtubs.
[0002] Bathtub drains include a “tub shoe” providing a drain aperture located at a low slope in the bathtub. The drain aperture may be formed by an upper portion of a metallic drain fitting designed to connect with a pipe that takes waste water from the bathtub. A drain stopper may be used to plug the drain aperture while the bathtub is in use.
[0003] Drop-in screens have also been used to prevent solid detritus (hair, clippings, etc.) from clogging the drain. There are disadvantages to the use of such screens. For example, the screen and plug may not be sized to fit together, and use of the screen can cause the plug to be lost. Also, the screen can loosen during use and float, allowing detritus to clog the drain. Such devices may also not provide the stock appearance of bathtub drain plugs. Additionally, it may not be possible to fill the bathtub unless the screen and drain plug are re-installed, which can be difficult, particularly if the bathtub is already partially filled with water.
[0004] Conventional screens for bathtub drains can also be difficult to clean/unclog, as many have more apertures in the screen than are necessary given the flow of water passing through the screen, or the screen may have a relatively large circumference, such that it is time-consuming to remove hair from it, for example.
[0005] Conventional drain plugs include rubber seals/plugs that simply press-fit into the drain aperture, and can easily loosen during use. Unless only an elastomeric plug is used, conventional drain plugs may require a fixed (threaded) connection with the drain opening, such as drain plugs that are rotated into a sealing connection using a lift-and-turn movement, which can be cumbersome and/or tricky to seal in place and to unseal. “Pop and seal” (e.g., spring-loaded) drain plugs have also been used, with similar problems. Such drain plugs are also typically fixed to the screen, allowing hair to wrap around the screen, which can be time-consuming to remove.
SUMMARY OF THE INVENTION
[0006] The objects mentioned above, as well as other objects, are solved by the present invention, which overcomes disadvantages of prior screens and drain plugs for bathtubs, while providing new advantages not previously associated with them.
[0007] The present invention includes a bathtub drain stopper assembly with a built-in screen which is removable from the stopper assembly for ease in cleaning. The stopper and screen are drop-in ready and easy to use, and assume use by a consumer with no plumbing experience. In appearance, the invention also provides, when installed, a stock appearance.
[0008] In a preferred embodiment of the invention, a drain stopper assembly for a bathtub having a drain aperture is provided, having a top cover, a gasket, a guide slide attached to the top cover, and a guide rod with proximal and distal ends, capable of sliding within the guide slide. A plurality of magnets may also be provided, including at least a first magnet located at the proximal end of the guide rod, and a second magnet located in the guide slide. Alternatively, instead of or in addition to magnets, a spring-loaded assembly may be used. When downward pressure is applied to the top cover, the gasket is enabled to seal against the drain aperture, and the guide rod slides upwardly within the guide slide to a second position; the guide rod may be facilitated in being maintained in the second position by the first and second magnets.
[0009] The guide slide may be removably attached to the top cover, and the gasket may be mounted to the guide slide. The top cover may include a knurled gripping surface. The guide rod may be integral with the slide guide, or may be removably attached to the slide guide.
[0010] A collecting filter may be provided which is removably attached to the distal end of the guide rod. The filter may be a cylindrical screen with a plurality of apertures located on a sidewall and a bottom surface of the screen. A third magnet may be located at the distal end of the guide rod, attracted to the collecting filter.
[0011] In an alternative embodiment, the distal end of the guide rod may include a finger useful for removing hair from the filter basket. The magnets may be encased by a protective coating. The top cover may be attached to the guide slide using a threaded connection. The collecting filter may include an upwardly facing nub, and the distal end of the guide rod may include an aperture sized to fit over the nub.
[0012] A method of providing a drain stopper assembly for a bathtub having a drain aperture, also forms a part of the present invention. The method includes providing a top cover, a gasket, a guide slide attached to the top cover, a gasket capable of being sealed to and unsealed from the drain aperture, and a guide rod having proximal and distal ends, wherein the guide rod slides within the guide slide. Pushing down on the top cover causes the guide rod to slide relative to the guide slide, enabling the gasket to be sealed against the drain aperture. Raising the top cover causes the guide rod to slide relative to the guide slide, enabling the gasket to be unsealed from the drain aperture. Magnetic or spring-loaded means may be used to facilitate the sealing and unsealing of the gasket relative to the drain aperture. A filter may be mounted within the drain aperture.
DEFINITION OF CLAIM TERMS
[0013] The terms used in the claims of the patent are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The novel features which are characteristic of the invention are set forth in the appended claims. The invention itself, however, together with further objects and attendant advantages thereof, can be better understood by reference to the following description taken in connection with the accompanying drawings, in which:
[0015] FIG. 1 is a partial side perspective view of a portion of a bathtub and drain aperture, and a preferred embodiment of the drain plug assembly of the invention;
[0016] FIGS. 2 a and 2 b are partial sectional views of the drain plug assembly taken along reference line 2 a - 2 a of FIG. 1 , showing the drain plug assembly in compressed and raised positions, respectively;
[0017] FIG. 3 is a perspective view showing the components of the drain plug assembly; and
[0018] FIG. 4 is a sectional view along reference line 4 - 4 of FIG. 3 , showing the guide slide and guide rod of the preferred drain plug assembly.
[0019] The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. In the drawings, like reference numerals designate corresponding parts throughout the several views.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Set forth below is a description of what are believed to be the preferred embodiments and/or best examples of the invention claimed. Future and present alternatives and modifications to this preferred embodiment are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure, or in result are intended to be covered by the claims of this patent.
[0021] Referring first to FIG. 1 , a bathtub 5 includes a bottom surface 6 with a drain aperture 7 into which drain plug assembly 10 of the present invention may be inserted.
[0022] Referring now to FIGS. 1-4 , drain plug assembly 10 may generally include a top cover 20 , a guide slide 40 attached to the top cover, a guide rod 50 attached or integral with guide slide 40 , and a filter basket 60 .
[0023] Top cover 20 may include a top portion 20 a and a bottom portion 20 b , as shown. (Alternatively, cover 20 may consist of a single cylindrical-shaped portion 20 b as is more conventional.) Top portion 20 a may have a smaller diameter and have knurled side surfaces 21 , for easier gripping. (Top portion 20 a need not be used, and only bottom portion 20 b may be used, if desired.) Bottom portion 20 b may include a cylindrical ring 23 with male/female threads 24 designed to mate with corresponding female/male threads 41 on guide slide 40 (see FIG. 3 ). Gasket 30 , which may be made of rubber or another suitable material, may include an inner ring surface 31 sized to fit over guide slide threads 41 , and may be fixed in place adjacent guide slide shelf 42 , between the guide slide and top cover, when the guide slide and the top cover are threadably attached. (Alternatively, the inner surface of ring 23 of top cover 20 may be connected in a frictional press-fit manner to the outer surface of the upper portion 40 a of guide slide 40 , obviating the need for threads 24 and 41 .) Gasket 30 is designed to provide a water-resistant seal over drain aperture 7 when drain plug assembly 10 is inserted into the drain aperture.
[0024] In the preferred embodiment, while the upper portion 40 a of guide slide 40 may be removably attached to cover 20 , the lower portion 40 b of the guide slide may be adapted to allow guide rod 50 to slide within the guide slide. For this purpose, a retaining clip 50 b with any suitable cross-section may be used to press-fit into and cover the upper opening of guide slide 40 , covering magnet 62 . The guide rod 50 may be permitted to slide within guide slide 40 , but is preferably prevented from dropping out of the guide slide (and thus potentially being lost down the drain opening), such as by forming channel 83 with step 83 a , such that the upper end of guide rod 50 with retaining clip 50 b will catch on step 83 a.
[0025] Guide slide 40 may be made with a single thick wall. However, as shown in FIG. 4 , it may be preferred to fabricate guide slide 40 with opposing inner 40 b and outer 40 a walls, to use less material and to allow for more rapid fabrication in an injection mold process, for example.
[0026] While in the preferred embodiment, the guide rod slides within the guide slide, those of ordinary skill in the art will appreciate that the guide rod could be configured so that it has a hollow shell that slides outside of the outer surface of the guide slide.
[0027] In the preferred embodiment, to facilitate providing the drain plug assembly in compressed, plugging ( FIG. 2 a ) and raised, unplugged ( FIG. 2 b ) positions, magnets may be used. Here, magnet 61 may be provided in guide slide 40 , such as within guide slide protuberance 46 , and magnet 62 may be provided at a proximal (upper) end of guide rod 50 (see FIG. 4 ). By insuring that these magnets, when located in proximity, attract each other, they will cause the drain plug assembly to be induced to, and/or remain in, the raised, unplugged position when that position is desired. Additionally, magnet 73 may be provided in a distal end protuberance 54 of the guide rod, insuring by its attraction to metal filter basket 60 , that the drain plug assembly will be induced to, and/or remain in, the compressed, plugging position when that position is desired. Magnet 73 need not be used, however, as the distal end 57 of guide rod 50 may be designed to have a press-fit connection to nub 64 .
[0028] Preferably, the magnets may be provided in a protective plastic, water-resistant sleeve, for example, so that they are not visible and they are not exposed to potential rust-inducing agents such as air and water.
[0029] Filter basket 60 is preferably made of a magnetized metal to insure attraction to magnet 63 . Filter basket may include apertures 61 on sidewalls 62 and bottom wall 63 , preferably roughly evenly-spaced and sized as shown, to catch objects which may clog the drain, such as hair and other detritus, while allowing water and smaller particles such as dirt which will not clog the drain to pass through the screen. An upwardly-standing locating nub 64 may be located on the upper surface of bottom wall 63 , for receiving a like-sized aperture 57 at the bottom of guide rod 50 , providing a frictional engagement that facilitates the user's proper location and attachment of the guide rod to the screen. Nub 64 may be a separate attachment or may be integrally made with filter basket 60 . Referring to FIG. 3 , the distal end of nub 64 that protrudes from the lower end of the basket may terminate in a small dimple or raised area 64 a . If nub 64 is integrally made with the basket, this obviates the need for dimple 64 a.
[0030] Accordingly, it will be appreciated that a drop-in-ready bathtub drain stopper is provided, with a built-in screen that is removable for cleaning of the filter basket. The device is easy to use with the consumer in mind, and requires no prior plumbing experience. The device of the present invention also does not sacrifice in appearance, as when installed it can still provide the bathtub with a conventional appearance. The invention also preferably provides magnetic technology for the drain-and-fill feature, which is easy to use and glides smooth.
[0031] It will also be appreciated that the bathtub drain plug assembly of the present invention need not be fixed to any other fixture or fixed object, and is easy to use. To plug the tub, the user simply pushes down on the top cover, causing the magnet at the distal end of the guide rod to be attracted to the filter basket, allowing gravity to keep the top cover down in the plugged/lowered position shown in FIG. 2 a , and inducing a water-resistant seal between the gasket and the upper bathtub surface 6 around drain aperture 7 . (As water fills the tub, this water-head pressure acts as an additional force tending to seal the gasket down against the bathtub bottom wall surface, insuring a water-tight seal.)
[0032] To drain the tub, the user simply pulls up on the top cover, releasing the gasket and causing magnets 61 , 62 to be located within their respective magnetic fields, causing the drain plug assembly to remain in the raised/open position shown in FIG. 2 b.
[0033] The top portion of the drain plug assembly is easily separated from the filter basket for easy cleaning. First, the user may simply grab hold of the top cover and lift the entire device out of the drain hole. Next, the basket and top portion of the drain plug assembly can be easily separated by pulling in opposite directions. Preferably, to insure the force required to remove the entire assembly 10 from drain aperture 7 less than the force required to separate the upper half of assembly 10 from filter basket 60 , aperture 57 on the distal end of guide rod 50 and upstanding nub 64 on basket 60 are precision-machined male and female ends that slide into each other with a tight tolerance, providing a frictional connection that will hold in place when desired, but will easily separate when pulled apart by a user, as needed.
[0034] Referring to FIG. 3 , protuberance 53 located at the distal end of guide rod 50 may be provided, and acts like a hook or finger to allow the user to easily clean the basket by swiping out hair in the basket, for example.
[0035] Persons of ordinary skill in the art will appreciate that the invention may be made of various metal and/or plastic materials. For example, top cover 20 may be made of chrome, brushed nickel, stainless steel, or other materials. “Economy” (all plastic) or “luxury” (all stainless steel and brass) models of the drain plug assembly may be provided, if desired. Color choices for the top may include oil-rub bronze, gold, silver or other colors. The guide slide and guide rod may be made of plastic, for example, or from a metal, if desired.
[0036] Use of the present invention will save on the use expensive plumbers to unclog bathtub drains, and also reduce or eliminate the use of drain-cleaning chemicals that may be harmful to the environment and/or toxic to breathe and contact with the skin or eyes.
[0037] The above description is not intended to limit the meaning of the words used in the following claims that define the invention. Persons of ordinary skill in the art will understand that a variety of other designs still falling within the scope of the following claims may be envisioned and used. For example, while preferred embodiments involving a top cover threadably attached to a guide slide have been disclosed, in other embodiments the top cover could be frictionally press-fit to the guide slide. Also, while the filter basket has been disclosed as removably engaged to the slide rod, it could be permanently attached instead. It is contemplated that these additional examples, as well as future modifications in structure, function, or result to that disclosed here, will exist that are not substantial changes to what is claimed here, and that all such insubstantial changes in what is claimed are intended to be covered by the claims.
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A drain stopper assembly for a bathtub having a drain aperture, and a method for using the assembly. A guide rod may be slid within a guide slide, allowing a gasket to be sealed or unsealed against the drain aperture. Magnets or, alternatively, a spring-loaded mechanism, may be used to facilitate sealing/unsealing of the gasket. A filter may be mounted within the drain aperture, and be removably or permanently attached to the assembly.
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REFERENCE TO OTHER APPLICATIONS
The method and structure of the present application may utilize improvements disclosed in our co-pending application Ser. No. 860,191 filed Dec. 15, 1977 which is a continuation of our application Ser. No. 616,256 filed Sept. 24, 1975, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method of producing heat for an area heating system remote from a thermal electric power station and to said power station for performing the said method.
Power stations used for remote area heating have the disadvantage that the efficiency drops owing to the elevated condensation temperature, so that the power yield for any given primary energy consumption is considerably less than in the case of conventional power stations. Since the temperature gradient in nuclear power stations is less than in fossil fired power stations, this advantage is particularly pronounced in the former.
The object of the invention is the utilisation of the waste heat from power station installations used for remote area heating, in which the efficiency of such installations is not subject to any load-dependent reduction.
The invention fulfils this object in a method of producing remote heat in power station installations, in which waste heat appears at a different temperature in dependence on the electric power generated, in that firstly the return water from the remote heating grid is subjected to the waste heat which is given off at a low temperature, that thereafter this water is stored and that finally this water is heated further by waste heat given off at a higher temperature and supplied to the inlet to the remote heating grid.
One way of performing this method is to utilize a multi-stage turbine which has at least one steam discharge between adjacent stages of the turbine and to provide a condenser downstream of the steam discharge. A further steam discharge is located downstream of the last stage of the turbine with a second condenser connected thereto. A water storage vessel is provided to which the cooling water of the second condenser is admitted during the period of peak load and from which the cooling water stream for the first condenser is withdrawn during the off-peak load period.
A further embodiment consists in that in power station installations, consisting of a base-load steam turbine installation with a condenser and a peak-load generator with a gas engine, e.g. a gas turbine, the latter being, if desired, arranged spatially separate from the former, the invention is seen in taking the input to the remote heating grid through a condenser and thereafter supplying it to a storage vessel from which the water for receiving the waste heat from the gas engine is withdrawn and supplied to the input to the remote heating grid.
In each case the quantity of water required for disposing of the heat is intermediately stored in a storage tank located in the vicinity of the power station. This storage tank is, for example, charged in the course of the day with water which has been pre-heated by condensation of the fully de-energised steam. During the night, during which in any case the electricity demand is less than during the day, the turbine unit is run at a lower energy level. The steam which has been tapped off is supplied to the condenser, which is now cooled by the water which has already been heated during the day, the water which has been preheated during the day being heated up to the required temperature at which it is utilised in the remote heating grid. The cooling water is discharged during the night preferably at an intermediate level of the storage vessel, whereas the fully heated water is returned in the upper region of the storage vessel. Preferably a device is provided at an intermediate level which discharges the water of that layer which has the correct temperature for any particular requirement. During the night the water volume which has been heated during the day and which has been stored at an intermediate temperature, is used up, and the vacated storage volume is again recharged by cold return water from the remote heating grid.
The invention will now be described with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic diagram of a power station installation embodying the invention, having several turbine stages.
FIG. 2 shows a schematic diagram of a power station installation embodying the invention having a base-load steam turbine and a peak-load gas turbine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
From the power station turbine 1 shown in FIG. 1 the fully de-energised steam passes into the condenser 2. A stream of somewhat less de-energised steam is condensed in a further condenser 3. From the return conduit 4 of the remote heating grid cold water reaches the storage vessel 5 and enters it at its lowest point. At an intermediate level a pivotable pipe 6 is arranged, through which the heated cooling water can be admitted at a level comprising that layer which coincides as accurately as possible with the cooling water temperature. During the day the supply of cold water which has entered during the night flows through the condensers 2 and 3, almost the entire volume of the storage vessel 5 being charged with heated cooling water in the evening. During the night relatively hot tapped-off steam is removed from the power station turbine 1 through the conduit 7. This steam is condensed in the condenser 8. In addition the heated cooling water is discharged from the interior of the storage vessel 5 through the pivotable pipe 6, heated to the remote heating temperature, and admitted to the upper part of the storage vessel, whence part of it is discharged to the input to the remote heating grid 9. The following morning the heating water supply of the previous day has been consumed, the lower half of the storage vessel 5 is filled with cold water fed in from the input 4, and the upper half with hot water which is conducted to the remote heating grid 9. Thereafter the next day's cycle commences.
A further increase in efficiency and output for the brief periods of peak demand can, in accordance with the invention, be achieved by providing a further storage vessel 10 which is provided either upstream of the return conduit 4 or through which cold tap water is passed. During these peak periods the waste steam from the turbine 1 is supplied to the evaporator 11 which, in operative association with the turbine 12 and the condenser 13, forms a low-temperature secondary circuit containing a low-boiling point working fluid. During the brief operational phase during the load peaks, the turbine 12 is also coupled to the generator 16. For disposing of the heat of condensation at a low temperature the content of the storage vessel 10 is conducted through the condenser 13. The large scale stream of cold water which passes through the storage vessel 10 between the inlet 14 and the outlet 15 is heated up by a few K.
The embodiment shown in FIG. 2 the turbine 21 generates the base load. The nuclear reactor 22 continuously supplies a constant stream of heat. The condensation takes place in the condenser 23. Through the conduit 24 the return flow of remote heat enters the storage vessel 25 at the bottom and is supplied to the condenser 23 by the pump 28 and is then admitted to the intermediate region of the storage vessel 25 via the three-way valve 29 and via the pipe 26 which is pivotable to different levels.
For generating peak loads an independent gas turbine installation (or a Diesel engine) is provided, which drives the generator 30.
The gas which has been compressed by the compressor 31 flows through the heating device 32, thence through the gas turbine 33 and, after being de-energised, through the heat exchanger 34. During peak load operation the heat exchanger 34 is, by means of the pump 35, supplied with hot water, which, upon rotation of the three-way valve 29 into the position 29a, originates partly from the condenser 23 and partly from the storage vessel 25. The water which has been heated in the heat exchanger 34 to the required remote heat temperature is admitted through the conduit 36 to the upper region of the storage vessel 25, and thence enters the input to the remote heating grid 29.
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In a thermal power station installation the waste heat of the last stage is utilized by storing the cooling water which receives this waste heat, and heating it further during the periods during which the installation is not on full load, whereafter it is supplied to the grid of a remote area heating system.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of application Ser. No. 09/324,249 filed on Jun. 2, 1999, entitled “Apparatus and System for Prompt Digital Photo Delivery and Archival”.
FIELD OF THE INVENTION
[0002] The present invention relates to digital cameras and particularly to digital cameras which include a radio frequency (RF) transceiver for transmitting digital photos to a remote destination according to user preferences.
BACKGROUND OF THE INVENTION
[0003] Digital cameras are increasingly popular, which popularity is due in part to their elimination of processing delays involved with conventional film-based photography. With a digital camera, one does not have to shoot an entire roll of film and send it to a processor for development before seeing the resulting photograph. Instead, one can immediately download a digital image to a computer and display the photograph, or in some instances link the digital camera to a TV monitor to display the photograph. Another attractive feature of digital cameras is that the digital images they create, after being stored on a computer, can be forwarded to others via e-mail or can be incorporated into other electronic documents, including Internet web pages.
[0004] However, the process of connecting the digital camera to a computer and then downloading images to the computer for storage and viewing can be complicated. Some digital camera manufacturers have attempted to make this process easier by including in the camera a standard format 3.5 inch floppy disk drive for storing digital images so that the images can be easily accessed by computers with similar disk drives. Others provide flash card memory which can store a high number of images, or provide an infrared (IR) port for transferring images to a computer.
[0005] Even with these features, the image transfer cannot be begun until the digital camera (or storage device) is physically connected to a computer, or in the case of digital cameras and computers which include IR transceivers these must be located in close proximity before a transfer can be made. For many users, this process is confusing and detracts from the usefulness of the device. When a user wishes to view or share access to a digital photo quickly, this delay and manual transfer process can be both inconvenient and frustrating.
[0006] Another potential problem with current digital cameras is that they generally require creation of a database of images on a home or office computer, which often has limited accessibility, is unsecured, and is infrequently backed up. With the growing popularity of Internet accessible software programs, and “network computers” which include little or no data storage, there is a need for a networked image storage and archival service that provides secure, reliable, and universally accessible image storage services. Such a service would allow shared access to and transfer of images by family or business groups in a format which would greatly enhance the ability to categorize and sort each image by time, date, and occasion, and which would at the same time greatly reduce the possibility of losing important images. The Fujifilm company is known to offer an Internet archival service in connection with conventional film processing, but there is no known similar service for digital photos.
[0007] When compressed, a color digital image is typically 10K bytes or more in size, and transmission of such an image requires from 10 to more than 30 seconds, depending on wireless modem transmission rates. Cellular service providers typically charge for total circuit connection time or, in the case of wireless data services providers, for the amount of data transferred, and it is therefore advantageous to reduce the required connection time to perform a file transfer or the amount of data to be transferred. One way to do this is to compress the file before transmission. But even when a file is to be sent to multiple recipients one would not want to initiate multiple calls in order to transfer the file to each recipient, even if the file is compressed. It would be beneficial to have a system which allowed one to forward an image file, with distribution instructions, to a central repository, and know that the repository would then save and/or automatically distribute the image file according to prior user instructions, without incurring another expensive wireless transfer.
[0008] Digital cameras which include the ability to effect a wireless RF image transfer are not known to be currently marketed in the United States. A search of issued U.S. patents has revealed U.S. Pat. No. 4,884,132 to Morris et al, which provides a “personal security unit” which includes a digital image sensor, a cellular transmitter, a window aligned with the image sensor, and which transmits digital information identifying the hand-held unit to a remote cellular receiving station where all cellular communications received from the personal security units are recorded. Morris states that the recorded data can be accessed at a later time if a crime is reported.
[0009] Another known device is disclosed in U.S. Pat. No. 5,712,679 to Coles which discloses a security system with a method for locatable portable electronic camera image transmission to a remote receiver. This device provides the means to transmit a video image along with device identifying information and position coordinate information to a remote receiver. Coles states that the transmission may be accomplished by cellular radio and is received by a remote receiver where the image may be displayed or printed by facsimile.
SUMMARY OF THE INVENTION
[0010] The present invention comprises a wireless digital camera device (also referred to herein as a wireless device) including a processor, RF communications device (modem), memory, and digital camera which is configured to transmit a digital data message, including at least a digital image, an account ID, and a recipient code, across a combined wireless and wired network to a host system at a predefined Internet Protocol (IP) address. The portable apparatus is programmed to minimize the number of user inputs required for operation in order to operate much like other automatic cameras, providing “aim and shoot” operation. While it is presently possible to assemble a portable device which can transfer data files, including image files, to a destination computer by using readily available commercial products, such as a portable computer, camera, and cellular modem, such a system requires user input to configure and initialize, including a destination phone number for modem dialing or a host IP or e-mail address to send the image to. The present invention provides a simple wireless photo delivery system which requires minimal user inputs for successful configuration and operation.
[0011] In order to simplify the wireless camera apparatus set up and operation, the present invention provides a user-friendly means to customize operational features of the camera. Many computer users today have access to web sites on the Internet, and are familiar with the process of interacting with programs and forms posted on Internet web sites. In one embodiment of the present invention, a digital camera service server provides a means for users to define distribution nicknames and custom operation options, and automatically downloads these custom operational parameters to the wireless camera whenever they are updated.
[0012] In order for an e-mail system to resolve e-mail addresses into IP addresses it is necessary for a user device to have access to a domain name server (DNS) resolver. This exchange of messages between the remote device and the DNS at time of message delivery is eliminated in one embodiment of the present invention by having e-mail addresses resolved into their corresponding IP addresses by the digital camera service server (subsequently referred to herein as the server) prior to downloading these IP addresses with address nicknames to the wireless camera device. This enables embodiments of the wireless camera device which contain a wireless packet data communications device such as a Cellular Digital Packet Data (CDPD) modem to construct and send messages directly to the intended recipient's known IP address in a protocol format known to those of ordinary skill in the art, such as TCP, Simple Mail Transfer Protocol (SMTP), Internet Message Access Protocol (IMAP), Multipurpose Internet Mail Extensions (MIME), Serial Line Internet Protocol (SLIP), Point to Point (PPP), or Post Office Protocol (POP) without reference to a DNS resolver.
[0013] Wireless device users may wish to maintain control over who can send messages to them, in order to avoid paying for unwanted message transmissions. Another aspect of the present invention allows messages generated by the wireless device to be formatted so that the message origin address appears as a server address. This causes all message replies to be routed to the server, which receives and filters all replies addressed to the wireless device and only forwards messages which are from approved sources and in appropriate formats to the wireless device.
[0014] There is then a need to provide an apparatus and system which will allow for effortless transfer of a message including a digital image, an account identifier, and an optional recipient code, across a combined wireless/wired network to a host device at a pre-defined IP address. One aspect of the invention provides a digital camera service server host device at the pre-defined IP address which can store portions of the message, and/or forward select portions of the message and digital image to one or more recipients associated with a message recipient code.
[0015] In the case where the delivery IP address corresponds to a server, the data message may be stored at the server for later access or may be immediately forwarded to one or more IP addresses that correspond to a recipient code included in the data message. When an image is to be sent to multiple recipients, it is much more economical to only incur one transmission from the wireless camera device across the wireless communications link to the server, and then forward the image to each intended recipient through a conventional wire-line or fiber optic network.
[0016] In one embodiment of the present invention, an account is established on the server which corresponds to at least one wireless camera device. This server may be a private system accessible only via a private network, or may be connected to the Internet and be configured to allow wireless device users to access the server by using commonly available world wide web browsers. In either case the server is preferably remotely accessible in order to establish or update account parameters, or to access previously transmitted digital images and or responses thereto. In the preferred system, each server account is password protected for access only by authorized users. Authorized users may update their server accounts to establish recipient codes, or nicknames, and associate these codes with one or more destination e-mail addresses, IP addresses, phone numbers (for delivery of audio messages), or storage destinations (such as a server path name), thereby creating nicknames for the purpose of controlling how messages will be archived and/or distributed to individuals or groups.
[0017] When certain account parameters, such as nicknames, are changed on the server, they are automatically flagged to be downloaded in a list to the wireless camera device the next time the wireless device contacts the server. Alternately, the wireless device may be programmed to get a fresh copy of account parameters, or portions thereof, upon each new connection to the server. This nickname list is viewable in a scrollable window on the wireless camera device, providing a quick means for selecting who a particular data message is to be sent to, without concern for entering an e-mail or IP address.
[0018] For example, a camera user who is employed as a Realtor may define both business nicknames and personal nicknames. Business nicknames may include codes based on property attributes (a 3BR2BA code for all customers who are currently looking for a house with at least three bedrooms and two baths) or may include codes for different communities or property price ranges. Finance companies could also use the wireless camera to automatically create a photo of the collateral property, as required in many states, and simultaneously send the photo to the loan processor and to an archive file.
[0019] Other potential uses for the invention include (i) photo-advertisements—for example, camera can be used by sales agents to send pictures to a list of current clients, to an office webmaster, print shops, etc., or to save photos in a pre-defined server directory; (ii) journalists could use the system to submit late breaking news pictures; (iii) insurance adjusters—photo with claim or file number can be mailed directly to the home office or saved in a pre-defined server directory associated with the file; (iv) police—photos of accident site/crime scene can be captured and archived; and (v) a holiday photo system where the camera can be rented while on vacation in order to have photos automatically e-mailed to a printing service, or to a list of friends/relatives with whom you want to share trip events.
[0020] In the preferred embodiment, the invention comprises a battery powered wireless camera device, including a digital camera for creating a digital image, a memory for storing digital images, a delivery IP address, and a list of nicknames, an RF communications device connected to the wireless device, and processor means for transmitting a message to the delivery IP address via the communications device. Backup memory in the form of a removable disk or memory card may be provided in some embodiments for message storage with or without message transmission. The message includes an account ID, a recipient code (nickname), and at least one digital image created by the digital camera. As further described in the Detailed Description section of this disclosure, in some embodiments, the message may include message origination date, time, a message classification indicator, digital audio recordings, and/or location coordinates, and in some instances may not include a digital image.
[0021] The delivery IP address may be saved in the wireless camera device memory in response to input commands entered at a device user interface, input commands entered remotely via the communications device, or input commands during manufacture of the wireless device. The RF communications device may be a circuit-switched data modem or packet data modem, and may respectively establish a switched connection through the Public Switched Telephone Network (PSTN) to the server or to a host device and router system at a particular phone number from which messages are transmitted to the destination IP address, or may transmit the message directly through a cellular service provider digital packet network connection, such as CDPD, to the destination IP address through an Internet connection.
[0022] In alternate embodiments, the wireless camera includes a microphone interface for recording audio messages to be transmitted in a digital format with messages. In such embodiments where the interface includes a microphone, a voice recognition module may be used to translate spoken messages into operational commands. For example, the wireless apparatus may be activated to record a spoken nickname, address, or alphanumeric identifier for association with the message, process this recording with the voice recognition module, and then include the character output of the voice recognition module as a nickname, e-mail address, classification or message field in the next message transmission. Other interface means may include a bar code scanner, or numeric or alphanumeric keypad
[0023] Another embodiment is configured to function as an enhanced digital phone that includes a digital camera. Other embodiments include an optional global positioning system (GPS) unit for capturing location data that may then be included in the message. Yet another embodiment of the invention includes a data port which is connected directly to the communications device so that the wireless camera device can be used as a portable RF modem for external devices which are connected to the data port from time to time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a high level diagram of the photo delivery system of the present invention.
[0025] FIG. 2 is a block diagram of the wireless device.
[0026] FIG. 3 shows a representative user configuration table for the wireless device.
[0027] FIG. 4 shows a representative recipient selection view of the wireless device interface means.
[0028] FIG. 5 shows a representative mode selection view of the wireless device interface means.
[0029] FIG. 6 shows a representative classification selection view of the wireless device interface means.
[0030] FIG. 7 shows a representative account configuration record on the server of the present invention.
[0031] FIG. 8 shows a server interface means display of account recipient information.
[0032] FIG. 9 shows a server interface means display of representative individual recipient information.
[0033] FIG. 10 shows a server interface means display of representative group information.
[0034] FIG. 11 shows a server interface means display for editing representative group information.
[0035] FIG. 12 shows a process flow chart for one embodiment of the wireless camera device of the present invention.
[0036] FIG. 13 shows a process flow chart of the register process of FIG. 12 .
[0037] FIG. 14 shows a process flow chart of the get image process of FIG. 12 .
[0038] FIG. 15 shows a process flow chart of the audio recording process of FIG. 12 .
[0039] FIG. 16 shows a process flow chart of the format process of FIG. 12 .
[0040] FIG. 17 shows a process flow chart of the custom input process of FIG. 16 .
[0041] FIG. 18 shows a process flow chart of the transmit process of the preferred embodiment wireless camera device.
[0042] FIG. 19 shows a data format for data transmitted from the wireless camera device to the server of the preferred embodiment.
[0043] FIG. 20 shows a process flow chart of how the server processes messages received from a wireless camera device.
[0044] FIG. 21 shows a process flow chart for how the server responds to wireless camera device queries.
[0045] FIG. 22 shows a process flow chart for how the server responds to messages addressed to a wireless camera device.
DETAILED DESCRIPTION OF THE INVENTION
[0046] As will be understood from reading and understanding the following more detailed description, the present invention includes a wireless digital camera apparatus, and in the preferred embodiment includes the digital camera apparatus as part of a digital photo delivery system, which system also includes a server that is accessible through the Internet for user updates. Each user of such a system has an assigned server account ID and password which is required in order to update account parameters and access messages stored on the server although in some embodiments users may designate that certain images may be stored in a public area from which they may be freely accessed or linked to. This photo delivery system 100 is shown in FIG. 1 as including a wireless camera apparatus 110 , which transmits and receives messages via a radio network 120 . The radio network 120 can be any data-capable airlink (such as GSM, TDMA, CDMA), or wireless data network such as CDPD, or may be a short range radio link such as an in-building network or a radio link between the wireless device and other devices via a standard protocol such as the Bluetooth Specification sponsored by Ericsson, IBM, Intel, Nokia, and Toshiba. The radio network 120 is connected to an external network 130 , which may be the Internet, an intranet, or other private data network. The external network 130 is connected to at least one wireless camera service server 140 , and one or more viewer stations 150 (which will ordinarily comprise a personal computer and may be configured to include a viewer microphone 160 or a viewer camera 170 ). In alternate embodiments the external network is connected to a printing service 180 .
[0047] Major elements of the wireless camera apparatus 110 are shown in block form in FIG. 2 , as including a digital camera 210 , a memory 220 , a processor 230 , a RF modem 240 which includes an antenna 250 , interface means 260 , and digital signal processor 266 , which in the preferred embodiment are integrated into one unit. However, the wireless camera device 110 and the server 140 may be programmatically implemented by using many general purpose hardware components. For example, the wireless device 110 may be implemented with a handheld PC such as the Mobilon HC 4100 connected to a CE-AG04 color digital camera card, both available from Sharp Electronics Corporation, and a wireless CDPD modem such as the Sage modem available from Novatel Wireless, Inc. Alternately, the wireless device may be implemented by programming a Novatel Wireless CONTACT handheld PC (which includes an integrated CDPD modem), now available for beta testing from Novatel, and which is connected to any one of several digital cameras presently available on the market. The invention may also be programatically implemented on a combination of notebook computer running the Windows 95 operating system, wireless CDPD modem such as the PM100C CDPD modem from Motorola, and digital camera, such as the QuickCam VC from Connectix Corporation or the CMOS-PRO from Sound Vision Incorporated, or the Sony Vaio C1 Picturebook computer that incorporates a digital camera, and a CDPD PC card modem such as the Sierra Wireless Aircard.
[0048] Although the RF modem for the preferred embodiment is configured for packet data transmissions, circuit switched modems may be used without departing from the spirit of the invention. For example, alternate embodiments may include a combined CDPD and circuit switched modem, such as the Sierra Wireless SB220 OEM communications module, in order to allow wireless communication via a circuit switched connection to the server 140 when the wireless device is used in an area where CDPD service is not available.
[0049] FIG. 3 shows a representative configuration table 310 for the wireless device which in the preferred embodiment system is built on the server 140 and stored in server memory, and downloaded to the wireless device memory 220 after each change to table contents, or upon initial activation of the wireless device 110 , although for wireless device embodiments with interface means 260 which provide the ability to input alphanumeric text, the configuration table 310 or portions of it can be modified directly on the wireless device 110 . In FIG. 3 the items in recipient code column 312 are nicknames that may be selected by users of the wireless device 110 in order to control distribution of messages transmitted from the wireless device. Optional recipient type column 314 represents an indication of whether the nickname designates a group nickname (G) an individual nickname (N) or a system processing code (S). Two system processing codes CUSTOM and HOLD are shown. HOLD is the default nickname that is used if no other nickname is selected. When the apparatus is activated to send a photo with HOLD, a message is constructed and sent to the server 140 where it is held for predetermined period of time to await further processing instructions. When the wireless device 110 is activated to send a photo with CUSTOM, a process is activated on the wireless device 110 to allow the user to designate a custom e-mail address prior to transmitting the photo message to the server. Recipient IP address column 316 corresponds to IP address data which is generated by the server 140 before downloading the table to the wireless device 110 , and which is applicable only when the nickname is for an individual. Although not shown here, the preferred embodiment configuration table 310 also includes a list of message classifications as further described in reference to FIG. 6 below, as well as other custom parameters used to control operation of the wireless device 110 .
[0050] FIGS. 4-6 show a portion of the preferred embodiment wireless device interface means 260 as including a configuration display 198 , mode display 200 , vertical scroll key 190 , horizontal scroll key 192 , and select key 194 . As will be apparent to one skilled in the art, the configuration display 198 and mode display 200 may be comprised of an active matrix display, LCD display, or other appropriate display means. In other embodiments the scroll keys 190 and 192 , and select key 194 , may be incorporated into a touch screen display.
[0051] Mode display 200 of the preferred embodiment includes three possible operation modes, “TO”, “MODE”, and “CLASS”, which are selected by the horizontal scroll key 192 , and the currently selected operation mode is highlighted. When the TO mode is selected, the preferred embodiment configuration display 198 shows up to four recipient codes and their corresponding recipient types from the current configuration table 310 . In FIG. 4 , three group nicknames and one individual nickname are displayed, with the current selection (“FAMILY”) being highlighted. Nickname selection in the preferred embodiment is controlled by the vertical scroll key 190 .
[0052] FIG. 5 shows that when the MODE operation mode view is selected on mode display 200 the configuration display 198 shows a list of current operation modes for that embodiment of the wireless device. The display shown is for an embodiment that allows operation in a “SEND”, “SAVE”, and “SEND LAST” mode. For illustration purposes, the preferred embodiment, which allows the capability to record an audio message for transmission along with a digital photo image, would have operational modes of “SEND”, “SEND W/AUDIO”, “SAVE”, “SAVE W/AUDIO”, “SEND LAST” and “AUDIO ONLY”, corresponding respectively to transmitting an image without an audio message, transmitting an image with an audio message, saving an image without transmitting it, saving an image and an audio message without transmitting, transmitting the last saved message, and transmitting only an audio message.
[0053] FIG. 6 shows that when the CLASS operation mode is selected on mode display 200 the configuration display 198 shows a list of current message classifications, which may be selected by operation of vertical scroll key 190 . When the wireless device 110 is activated to send a message with the CUSTOM classification selected, a process is activated on the wireless device 110 to allow the user to designate a custom message classification, such as a customer number or name, prior to transmitting the photo message to the server 140 . Various message classifications may be customized on the server 140 of the preferred embodiment and downloaded to the wireless device 110 along with other portions of the configuration table 310 as will be later described in relation to FIG. 13 .
[0054] FIG. 7 shows a representative account configuration record on the server 140 of the present invention. In the preferred embodiment wireless photo delivery system each wireless device user will have an account configuration record on the server which includes an account ID 321 , a password 322 , an account name 323 , a contact name 324 , a billing address 325 , a camera id 326 which corresponds to the RF modem 240 network equipment identifier or IP address (for those devices with a packet data modem), a wireless device dial ID number 327 corresponding to the phone number associated with the RF modem 240 (for those devices with a standard circuit switched cellular modem), and date fields 328 and 329 corresponding to the dates for which account service has been established. Other embodiments include a Direct or Server switch field 330 that is used to indicate whether wireless device messages to individual nicknames will be transmitted first to the server for distribution or directly to the nicknames associated IP address. In such embodiments, only messages that are transmitted to the server can be archived.
[0055] FIGS. 8-11 depict server interface means displays in the preferred embodiment for establishing and maintaining account recipient information which are preferably accessible via any Internet browser program, and which are stored in server database tables, along with the FIG. 7 account configuration record, in any number of ways which will be apparent to those who are skilled in the relevant art using standard techniques such as active server pages accessing a relational database. FIG. 8 shows a people or individual address screen 340 view of all account message recipients in column 342 , associated nicknames in column 344 , associated e-mail addresses in column 346 , and edit and delete selector buttons in columns 348 and 350 . Other user selection buttons in this screen view are a drop down list view selector 352 and a group view selector button 354 . The top of this display shows the account e-mail address 341 that is associated with this server account. This address 341 in the preferred embodiment is comprised of the Account ID (represented here as XXXXXX), and the server domain name (represented here as YYYY.COM). In one embodiment, any e-mail messages that are received by the server for this e-mail address in an acceptable format from authorized e-mail addresses (as further described below) will be forwarded to the associated wireless device.
[0056] FIG. 9 shows a server interface means display address book detail screen 360 of representative individual recipient information, corresponding to the last address book entry shown in FIG. 8 , and indicating the allowed level of detailed information which is stored on the server 140 for each account individual recipient record in the preferred embodiment. Most of these fields are self-describing, but e-mail reply OK indicators 362 and 364 are used by one embodiment server to build an account table of all e-mail addresses where this indicator is set to Y. This table is checked when the server receives e-mail addressed to the account e-mail address, and if the sender's e-mail address is found in the table then the e-mail will be forwarded in an appropriate format to the wireless device. Phone numbers 366 are optional, but are included for embodiments that are capable of forwarding wireless device messages that include an audio portion to a telephone or voice mail number, which can be accomplished in many ways apparent to those skilled in the relevant art. Path 367 is optional and is included for embodiments where the message is to be saved under a specific server directory path in lieu of or in addition to being distributed.
[0057] FIG. 10 shows a server 140 interface means group view display 370 of representative group information that is accessed in the preferred embodiment by selecting the group view selector button 354 shown in FIG. 8 . This group view display 370 shows currently defined account groups and includes a people view selector button 372 , an add new entry selector button 374 , a group names display column 376 , an edit selector button column 378 for each group name, and a delete selector button column 380 . Selection of people view button 372 will take you back to the view of FIG. 8 , and selection of add new entry selector button 374 or any edit selector button in column 378 will take you to the group detail view of FIG. 11 .
[0058] Server 140 interface means group detail view display 390 for editing representative group information in the preferred embodiment is shown in FIG. 11 . This particular group detail view shows hypothetical entries for a group name “MANSE” in group name selector field 392 . When the detail view 390 is activated by the add new entry selector button 374 of FIG. 10 , the group name selector field would be blank, and all defined individuals would be displayed in non-member display column 394 . The preferred group detail view 390 includes vertical scroll bars 396 and 396 ′ and a group member display column 398 . Other user selectable buttons on the preferred group detail view include add, remove, delete, and done buttons, which operate respectively to add highlighted non members shown in column 394 to the group, to remove highlighted members shown in column 398 from the group, to delete the entire group, or to return to the group view display 370 of FIG. 10 after processing any changes.
[0059] FIG. 12 shows the overall method used to operate one embodiment of the wireless camera device of the present invention that includes both switched circuit cellular and wireless packet data modem capabilities. The process begins at block 402 where a flag is checked to determine whether the wireless packet data modem is to be used. If so, processing continues with the registration process of block 404 , which is shown in further detail in FIG. 13 . In the alternative the registration process is skipped and (although not shown here) wireless devices with circuit switched modems may contact the server 140 to obtain a fresh configuration table 310 before processing continues at block 406 , where processing halts until a signal is received indicating the send key 196 has been activated. At block 408 the operation mode is checked, and if the SEND LAST switch is set, processing branches to block 410 where the first previously held message is marked to be sent, after which processing returns to a wait state at block 406 . If the send last flag is not set, and the operation mode is not AUDIO ONLY, the GET IMAGE routine of FIG. 14 is activated at block 412 . If at block 414 the AUDIO ONLY, SAVE W/AUDIO, or SEND W/AUDIO operation mode is set, the AUDIO routine of FIG. 15 is activated at block 416 before activating the FORMAT routine of FIG. 16 at block 418 . If at block 420 the operation mode is set to SAVE or SAVE W/AUDIO processing branches to block 422 where the formatted message is saved in memory 220 and marked to be held in the wireless device memory, but if the operation mode is not set to save the message, then at block 423 the message is saved in memory 220 and marked to be sent as soon as possible, and at block 424 the Transmit function of FIG. 18 is invoked, if this is not already active. In either case processing continues at block 426 where if memory is full, a warning is issued to the operator via the user interface means 260 which, in those embodiments that have flash memory or other removable memory devices, would prompt the user to replace memory device 220 , before branching back to the beginning of the method at block 400 . While this describes the best mode embodiment process, it will be apparent to those skilled in the art that many steps may be executed in an altered order or may be otherwise modified without departing from the scope of the invention as claimed herein.
[0060] FIG. 13 shows a process flow chart of the registration process of FIG. 12 that is activated in the preferred embodiment as well as any other embodiments that include a wireless packet data modem. Once registered with a wireless packet data service provider network, wireless packet data modems can remain registered for an indefinite period of time and most such modems, including the wireless packet data modem of the preferred embodiment, periodically query the network to verify that the device is still registered and set an indicator if the registration is dropped. In most instances, this FIG. 13 routine will execute only once upon powering up the wireless device 110 , and thereafter the indicator check at block 432 will branch to return back to the calling routine of FIG. 12 . In case the wireless device is not registered with the network, a registration routine on the RF modem 240 will be initiated to register with the network at block 434 . Next, at block 436 a query will be transmitted to the server 140 indicating that the device is registered, and requesting the server to transmit a copy of the configuration table 310 if this has been updated since the last time the wireless device was used. Finally, at step 438 the wireless device will receive and save any configuration table updates received from the server. In alternate embodiments, the wireless device 110 may simply log in to the server and retrieve its associated configuration table 310 in a manner well known in the art.
[0061] FIG. 14 shows a process flow chart of the get image process routine that is activated from block 412 of the preferred embodiment main process of FIG. 12 . This process initially signals the digital camera 210 to save a digital image at block 440 , may then compresses this image in memory 220 according to a standard compression scheme such as GIF or JPEG at block 442 , and for embodiments with a interface means 260 which includes a display capable of showing a reduced version of the image, display the image at block 444 . Other embodiments may alternately be configured to constantly display the image currently being received by the digital camera 210 , or in very simple embodiments may be configured only with a viewfinder and have no interface means 260 capable of displaying any image. Still other embodiments may skip the compression stage as it is recognized that larger files generally are more detailed and desirable, and compression to a small size prior to transmission may be less important in the future as greater wireless bandwidth becomes available.
[0062] FIG. 15 shows a process flow chart of the audio recording process of FIG. 12 as including a first processing step 450 which displays or plays a visual or audible prompt asking the wireless device user to record a voice message. Wireless devices which are equipped to allow audible message recording, including the preferred embodiment, have an interface means 260 which includes a record button which must be depressed and held while a message is recorded at block 452 . Otherwise the record function could be automatically activated for a set period of time at block 452 . After the recording ceases, the message is played back at block 454 , and the user is asked at block 456 if the message is acceptable. If the user indicates the message is acceptable, the audio process ends, and if the message is not acceptable processing branches back to block 450 to repeat the message recording process.
[0063] FIG. 16 shows a process flow chart of the preferred embodiment message format process 418 of FIG. 12 as including a first check 460 to determine whether the operation mode is set to include a custom classification. If so, the custom input process is invoked at a first entry block 466 with a parameter indicating that a custom classification is requested, before processing continues at block 461 where the message header is constructed in a buffer area of memory 220 . This message header 534 , as shown in more detail in FIG. 19 , includes such data as the account ID, Classification, date, time, and location coordinates if available. At block 462 the currently designated recipient code 536 is moved into the buffer area. At block 464 a check is performed to determine whether a custom recipient code/e-mail address was requested. If so, the custom input process is invoked at a second entry block 466 ′ with a parameter indicating that a custom address is requested, after which the custom address is moved into the buffer area at block 467 . Otherwise, processing continues at block 468 where the image is moved into the buffer area. Then at block 470 a check is performed to determine whether the AUDIO ONLY, SAVE W/AUDIO, or SEND W/AUDIO operation mode is set, indicating that an audio message was recorded. If so, the audio message is moved into the buffer area at block 472 . Otherwise, processing continues at block 474 where an end of message indicator is moved into the buffer area. Throughout this process appropriate delimiters will be added to indicate message field boundaries, and a current message length field updated appropriately, in a manner which is well known in the art.
[0064] In other embodiments, the message may be formatted by the wireless device 110 , and account ID and recipient code transmitted to the server, by a different mechanism without departing from the spirit of the invention. For example, an image file may be assigned a unique file name, including the account ID, recipient code, and an image identifier, for later transfer via FTP Put command to the server 140 . Similarly, audio messages could be sent separately to the server 140 under a corresponding file name for later association with the image file by a process on the server.
[0065] FIG. 17 shows a process flow chart of the preferred embodiment custom input process 466 and 466 ′ of FIG. 16 , wherein at block 480 a check is performed to determine whether the routine was activated to provide a custom address or a custom classification. If for a custom address, the user is prompted by the interface means 260 display or by audio prompt to enter the recipient's e-mail address. The address is entered via the user interface means 260 , via a microphone and voice recognition module on certain embodiments or via other input means such as selections from a scrollable list of alpha numeric characters, or via keyboard input. The address is displayed at block 484 and the user is asked to verify this at block 485 . If the address displayed is incorrect, processing branches back to block 482 , and, if correct, processing continues at block 486 where the custom address is saved in memory. If the custom input routine of FIG. 17 is entered to provide a custom message classification, then a similar process is executed at blocks 488 through 494 whereby a custom classification is entered and saved in a designated area of memory 220 .
[0066] In the preferred embodiment a separate processing loop, as shown in FIG. 18 , is invoked to transmit messages from the wireless device to the server. This allows users to quickly take several pictures without waiting for the prior picture to be transmitted. A standard wireless packet data routine is utilized to receive messages by the RF modem 240 in a manner well known to those of ordinary skill in the art and is not further described here. As previously described in relation to FIG. 12 , the transmit process is invoked (if it is not already active) after a message has been formatted in memory 220 for transmission. Upon activation an indicator on the wireless device is checked to determine whether the transmission is to be accomplished as packet data or as circuit switched data. This indicator may be set to only allow packet or circuit data transmissions, or may be set dynamically in embodiments which include the capability to transmit both as packet data or circuit data depending on the availability of a packet data network, so that one form of transmission may be established as preferred, but if that form is not available, then the other form of transmission will be attempted.
[0067] If as circuit switched data, block 512 process is invoked to establish a switched circuit modem connection between the wireless device and either the server 140 or a known host which is capable of transmitting the message according to an IP protocol to a defined destination IP address. Formatted messages are stored in memory 220 until transmission is complete, and at block 514 a pointer is established to the first message in queue in memory. At block 516 the message is checked to determine whether the message is on hold, or is marked to be sent, and if marked to be held processing branches to block 526 . If not held, a second check regarding packet data is performed at block 518 , and if the wireless device 110 is set for packet data transmissions a routine at block 520 formats the message for transmission, preferably by the TCP/IP protocol, or by other IP protocols which are well known to those of ordinary skill in the art of packet data transmissions, and activates the RF Modem, which in some embodiments may be preconfigured to transmit the message according to a particular protocol.
[0068] If the wireless device 110 is not set for packet data transmissions, then the message is transmitted to the server 140 or a known host which is capable of forwarding the message according to an IP protocol to the server. This is preferably accomplished as an asynchronous data transmission in compressed form, such as the V.42bis compression protocol in order to reduce transmission time.
[0069] Regardless of the type of transmission, after the transmission is attempted in the preferred embodiment, common processing continues at block 524 , and if no error flag was set during transmission, the transmitted message is deleted from memory. However, in other embodiments, the user may wish to maintain a copy of the message after transmission, for back up or other purposes, in which case the message may be marked to be held instead of being deleted at this point. At block 526 the next message slot in the memory queue is pointed to and if another message is in the memory queue processing continues back at block 516 . Otherwise, a final check is performed at block 528 to see if a circuit switched data transmission is being used, and if so, the circuit is terminated at block 530 .
[0070] In addition to the processing routines which drive the server interfaces of FIGS. 7 through 11 and the database calls which are required to support these interfaces, the preferred embodiment server 140 includes several specific processes related to message transmissions both from and to wireless camera devices 110 , and which are shown in FIGS. 20 through 22 . FIG. 20 shows a process flow chart of how the server processes messages received from a wireless camera device. At block 544 the server receives a message, parses out information such as account number, image, audio data, date, time, classification, location, and recipient code which is included in the message, saves this in a server memory for future access and in a holding area designated for this account, and if a path is associated with the recipient code saves the message at that location. At block 546 the server determines whether the message is to be held or if the account is no longer valid, in which case no further action is taken, and the message will be marked for deletion after a predetermined period of time absent further action. At block 548 , if a custom address was included in the message, then processing branches to block 550 , where the address may be resolved into an IP address before being formatted as a standard e-mail message and transmitted to the recipient or this may be handled automatically by a commercially available e-mail program such as MS Outlook, depending on how the server is configured. Otherwise, if the message is to an individual then processing continues directly at block 554 . If the message is to a group, then a list of recipient addresses is retrieved at block 556 , and at block 558 the message is formatted as a standard e-mail message and transmitted to each recipient. Some embodiments may only send out a thumbnail version of images and/or a hyperlink to the server path or URL where the message has been saved.
[0071] Certain embodiments may allow delivery of the audio portion of messages to a recipient's phone number, in which case a separate server process would be invoked to make a set number of attempts to deliver the message to the listed phone number or a voice mail system at that number, after which the message would be marked undelivered. If the message recipient wished, they could leave a reply message immediately, via an interactive voice process on the server, which reply the server would later attempt to deliver, or the recipient could call back later to a designated number and enter a response ID number, both as specified with the original message delivery, in order to leave a reply message.
[0072] FIG. 21 shows a process flow chart for how the preferred embodiment server 140 responds to queries from the wireless camera device 110 in order to download the current account configuration table to the wireless device. At block 572 the server receives a query from the wireless device as previously discussed in relation to FIG. 13 . If there have been any changes to the account since the last download, then processing continues from block 574 to block 576 where the server contacts a domain server in order to resolve all individual IP addresses for e-mail addresses associated with account individuals' e-mail addresses. At block 578 the updated configuration table is transmitted to the camera in a prescribed format, and the last download data is updated for the account. In other embodiments the wireless device 110 may simply log into the server 140 upon initial activation of the wireless device and registration with the wireless packet data network and retrieve its associated configuration table, as by an FTP Get command.
[0073] FIG. 22 shows a process flow chart for how the server responds to messages received by the server 140 and addressed to an address associated with a wireless camera device 110 . The message is typically received at block 588 as an e-mail message, but as previously discussed may comprise a voice mail message. If the account is valid, then processing will continue at block 594 ; otherwise the server will attempt to respond that the account is no longer valid. As discussed previously in relation to FIG. 9 , the account data is checked at block 594 to determine whether a reply from this source is authorized. If a reply is authorized, the message is reformatted in a form which will be recognized by the wireless device, and transmitted to the camera ID at block 596 . In either case, in the preferred system the reply is archived for a predetermined number of days before being deleted, and will be accessible for review prior to deletion via Internet account access or via other means, such as for example embodiments where the server 140 and wireless device 110 are configured respectively as server and client using the IMAP protocol as previously discussed.
[0074] Use and operation of the preferred embodiment of the present invention may be better understood by reference to the figures in connection with the following description. The wireless device user will obtain a wireless device 110 and register it with a wireless packet data network service provider, who will assign a camera id 326 , or dial id 327 , account validity dates 328 and 329 , initialize the RF modem to recognize the appropriate id, and arrange for initialization of the account information 320 ( FIG. 7 ) on the server 140 . The user will then be able to logon to the server and initialize preferred address book entry details as shown in FIGS. 8-11 , or this information may be provided directly to a service provider who will initialize the address book on behalf of the user. Alternately, and in cases where the user does no own a wireless device but only rents one on occasion, the user may establish an account and initialize address book details at his or her convenience prior to obtaining a wireless device, and the wireless device provider will associate a particular device with this account information when the user picks up the device. Next, the user can activate the wireless device 110 , which will automatically initiate the process of FIG. 12 to register the wireless device with the packet data network and download updates as previously described in relation to FIGS. 13 and 21 . After the configuration table is initialized on the wireless device, the user will be able to operate the wireless device 110 interface in order to select a recipient code, mode, and classification, as described in relation to FIGS. 4-6 . If this step is skipped, the default values for any transmitted messages will be respectively set for HOLD, SEND, and NONE. The user will then be able to activate the camera by pressing the send key 196 , which will activate processing of FIG. 12 subsequent to block 406 in order to capture an image and transmit it as part of a message to the server 140 for processing and distribution according to the selected recipient code as described in relation to FIG. 20 .
[0075] Whereas the present invention has been described in detail with specific reference to particular embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the present invention as hereinbefore described and as defined in the appended claims.
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The invention comprises a wireless apparatus and system for automatic processing of digital “messages” to a remote system at a predefined destination address. Initial transmission occurs via a wireless network, and the apparatus process allows the simultaneous capture of new messages while transmissions are occurring. The destination address may correspond to an e-mail account, or may correspond to a remote server from which the message can be efficiently processed and/or further distributed. In the latter case, data packaged with the digital message is used to control processing of the message at the server, based on a combination of pre-defined system and user options. Secured Internet access to the server allows flexible user access to system parameters for configuration of message handling and distribution options, including the option to build named distribution lists that are downloaded to the wireless apparatus. For example, configuration data specified on the server may be downloaded to the wireless apparatus to allow users to quickly specify storage and distribution options for each message, such as archival for later retrieval, forwarding to recipients in a distribution list group, and/or immediate presentation to a monitoring station for analysis and follow-up. The apparatus and system is designed to provide quick and simple digital message capture and delivery for business and personal use.
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CROSS-REFERENCE TO RELATED APPLICATION 35 USC §119(e)
[0001] Not applicable
FIELD OF INVENTION
[0002] The present invention relates generally to trailer hitch mounting inserts used to form a self-supporting, interlocking, modular component, variable width, length and height apparatus for suspending or elevating items above the ground.
BACKGROUND OF INVENTION
[0003] The use of trailer hitches on automobiles is very common today. Trailer hitches can be temporarily installed on most vehicles. Some vehicles, such as pick-up trucks, SUVs and off-road vehicles typically have permanently installed trailer hitches. Today, a common trailer hitch consists of a two-piece apparatus comprised of a receiver which is permanently mounted to the vehicle; and, an insert.
[0004] One common insert is a ball hitch. Another common insert is a key-vault. Yet another common insert is a flag pole holder. And still yet another is a cargo carrier or a bike rack. This list is not limiting and is offered to illustrate the widely acceptable and common uses of trailer hitches.
[0005] To meet the market demand for towing, supporting, extending, and carrying objects by using the trailer hitch, many manufacturers have products in the market to meet demand for durable, easy to use and interchangeable applications. Accordingly, the manufacturers have developed products with dimensions for the standard ball size, standard receiver size and standard tongue size to allow interoperability between trailer hitch receivers and the apparatuses inserted into them.
[0006] The present embodiment introduces a new apparatus to enable users to multiply the number of objects being supported by a single trailer hitch receiver connected to a vehicle, or mounted to a suitable supporting structure, or supported by stands. The present embodiment also introduces a new apparatus designed to meet the needs of using a trailer hitch receiver in an array of multiple supporting mounts simultaneously. Furthermore, the present embodiment introduces a modular apparatus system whereby the user can configure the array of multiple supporting mounts to occupy lateral and vertical space directly behind and above the vehicle so as not to extend beyond the dimensions of the vehicle to which the array is attached; to extend completely outside the dimension of the vehicle to which the array is attached; to rise and be suspended above the vehicle to which the array is attached; or, any other configuration to which the user desires.
[0007] The present embodiment introduces a simple modular concept wherein each modular component has a receiver mating end, the tongue, of appropriate dimension to fit into the standard trailer hitch receiver; while also having opposing receiver end or ends to accept support inserts. The present embodiment provides flexibility in configuring the array of multiple supporting mounts using two basic modules, an extension module and a “t” module which interconnect. The limitation of the present embodiment is the number of modules available on hand.
[0008] The present embodiment provides a new solution for multiple supporting mounts configured in array for use illustrated by an amateur radio operator requiring multiple antennas suspended at various heights above the ground, directly behind, or completely outside the wheel wells of a pick-up truck. The array can also be illustrated by using the array to support a BBQ grill, foot-step, satellite dish, a television monitor and a college flag elevated on a flag pole at a tailgate event in the parking lot of a stadium. And yet another illustration for using the array could be a Community Emergency Response Team mobile command center supporting HAM radio antenna, flood lights, loud speakers, table tops or umbrellas when deployed into a disaster area after an earthquake, flood, hurricane or tornado.
[0009] Although there are several apparatuses which may have various functions related to the modular expandable trailer hitch mounting array system, none of these either separately or in combination with each other, teach or anticipate the current invention. Therefore, there remains an unmet need in the field of the apparatus to enable users to multiply the number of objects being supported by a single trailer hitch receiver. The current invention will fulfill this unmet need.
SUMMARY OF INVENTION
[0010] The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed invention. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
[0011] The present embodiment introduces a modular apparatus comprised of two basic components used to form mounting arrays connected to a standard trailer hitch receiver mounted to a vehicle, post or other suitable structure with additional supplemental attachments being included with which more complex arrays can be assembled.
[0012] The preferred material for constructing the basic modular components is square metal tubing. The first modular component, the extension module, is a two-piece extension module constructed using a larger outer and smaller inner element. The larger outer element is formed by cutting a larger outer square tube to length and drilling hole pairs at both ends suitable to accepting a standard trailer hitch pin or threaded bolt used to interlock other smaller, inner elements which are inserted into the larger outer element. The opposite end of the first larger outer element is used as a receiver for accepting other extension modules; receiving custom mounts made to support items such as a pole to mount televisions, satellite receivers and antenna, foot-steps, BBQ grills, fryers or table tops; or, receiving any other commercially available supporting mounts. The opposite end of the larger outer element is also used as a receiver to receive the second inner element; which when extended forms the tongue to insert into the trailer hitch receiver or receiver of other first or second modules.
[0013] The second inner element of the first modular component is formed by cutting a smaller inner tube to length and drilling a single pair of holes at the distant end and also drilling a series of hole pairs at the insert end.
[0014] The function of the extension module is to separate the supporting mount in spatial distance to the single trailer hitch receiver. The dimensions of the extension module are calculated to provide flexibility in using the modular system to form an array which can be configured completely within the wheel-well of the vehicle to which the array is attached; or, which can be configured to extend wholly outside the wheel well of the vehicle to which the array is attached. The extension module is also specifically dimensioned to minimize the number of modules a user must have on hand to configure the array.
[0015] The second modular component, the “t” module, is a two-piece “t” module constructed similarly to the extension module using a larger outer and smaller inner element. The larger outer element is formed by cutting a larger outer tube, of same dimension as the tube used for the extension module, to length and drilling hole pairs at both ends, and on each end of the “t” cross-member described below, suitable to accepting a standard trailer hitch pin used to interlock other smaller, inner elements which are inserted into the larger outer element. One end of the first larger outer element is used as a receiver for accepting other extension modules; receiving customer mounts made to support items such as pole to mount televisions, satellite receivers and antenna, BBQ grills, fryers or table tops; or, receiving commercially available supporting mounts. The opposite end of the larger outer element and both ends of the “t” cross-member is also used as a receiver to receive the second inner element.
[0016] Additionally, the “t” cross member is formed out of the first outer element which is modified by cutting a segment from the mid span of the first outer element, rotating that span 90 degrees and welding the rotated segment to the open ends of the first outer element which resulted from cutting the first outer element. Additionally, a plate which can serve as a step and which also provides support to the “t” cross member welds can be attached to the top side of the “t” module positioned across the end of the “t” module.
[0017] Finally, additional hole pairs are drilled on the ends of the segment forming the cross member of the “t”. Once the welds are complete, the first outer element will have the form of a cross. Each end of the “t” cross member is used as a receiver for accepting other extension modules; receiving customer mounts made to support items such as pole to mount televisions, satellite receivers and antenna, BBQ grills, fryers or table tops; or, receiving commercially available supporting mounts.
[0018] The second inner element of the second modular component, the “t” module, is formed by cutting a smaller inner tube to length and drilling a single hole pair at the distant end and also drilling a series of hole pairs at the insert end. This element, which when extended, forms the tongue to insert into the trailer hitch receiver or receiver of other first or second modules.
[0019] For both the first and second module, the small inner elements can be inserted into the open end of the larger outer elements to form the tongue which inserts into the receiver end of the modules or a standard trailer hitch receiver.
[0020] Using these two components, a user may form a suitable array of multiple supporting mounts connected to the vehicle at a single trailer hitch receiver. By way of illustration, using a single “t” module, a user can extend the support mount for a flag pole far enough away from the rear of a pick-up truck to allow sufficient clearance to lower the tailgate. Additional array configurations are possible when utilizing elbow or riser adapters connected to the first or second modules. The elbow and riser adapters can be utilized in series with multiple extension or “t” cross member modules.
[0021] Alternatively, the user can configure the array so that all supporting mounts extend beyond the outside wheel well base of the vehicle; or, by using elbow and/or riser adapters, position supporting mounts above and inside the perimeter of the bed of a pick-up truck.
[0022] Since the modules presented by the present embodiment are used to form the self-supporting array of multiple supporting mounts, originating from a common connection point at the trailer hitch receiver, the vehicle can be moved with the array configured and attached to the vehicle.
[0023] Still other objects of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described the embodiments of this invention, simply by way of illustration of the best modes suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modifications in various obvious aspects all without departing from the scope of the invention. Accordingly, the drawing and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Various exemplary embodiments of this invention will be described in detail, wherein like reference numerals refer to identical or similar components, with reference to the following figures, wherein:
[0025] The novel features believed characteristic of the embodiments of the present application are set forth in the appended claims. However, the embodiments themselves, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein:
[0026] FIG. 1 is a simplified schematic illustrating an array of the first and second modular components using a trailer hitch receiver to suspend the array also illustrating multiple supporting mounts simultaneously;
[0027] FIG. 1A is a simplified schematic illustrating an array of the first and second modular components using a trailer hitch receiver to suspend the array also illustrating multiple supporting mounts simultaneously with additional support stands deployed to increase the array stability;
[0028] FIG. 2 is a simplified schematic illustrating an array of the first and second modular components with multiple stands illustrated to stabilize a free standing configuration array of the first and second modular components also illustrating multiple supporting mounts simultaneously;
[0029] FIG. 3 is a schematic of the second modular component, the “t” module.
[0030] FIG. 4 is a schematic of the first modular component, the “extension” module
[0031] FIG. 5 is a schematic of the “elbow” adapter.
[0032] FIG. 6 is a schematic of the “riser” adapter.
[0033] FIG. 7 is a schematic of the “short” support mount.
[0034] FIG. 8 is a schematic of the “long” support mount.
[0035] FIG. 9 is a schematic of the “tall” support mount.
[0036] FIG. 10 is a schematic of the stand.
[0037] While the system and method of use of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present application as defined by the appended claims.
DETAILED DESCRIPTION
[0038] The claimed subject matter is now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident; however, that the claimed subject matter may be practiced with or without any combination of these specific details, without departing from the spirit and scope of this invention and the claims.
[0039] Illustrative embodiments of the system and method of use of the present application are provided below. It will of course be appreciated that in the development of any actual embodiment, numerous implementation-specific decisions will be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0040] The system and method of use in accordance with the present application overcomes one or more of the above-discussed problems commonly associated with trailer hitch mounting mechanisms. Specifically, the apparatus and method of use of the present embodiment provides rapid and effective means to deploy an array of multiple mounting supports for use during amateur radio filed operations, CERT disaster response situations, while tailgating and other applicable situations discussed above. These and other unique features of the apparatus and method of use are discussed below and illustrated in the accompanying drawings.
[0041] The apparatus and method of use will be understood, both as to its structure, configuration and operation, from the accompanying drawings, taken in conjunction with the accompanying description. Several embodiments of the system are presented herein. It should be understood that various components, parts, and features of the different embodiments may be combined together and/or interchanged with one another, all of which are within the scope of the present application, even though not all variations and particular embodiments are shown in the drawings. It should also be understood that the mixing and matching of features, elements, and/or functions between various embodiments is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that the features, elements, and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless described otherwise.
[0042] The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to enable others skilled in the art to follow its teachings.
[0043] Referring now to the drawings wherein like reference characters identify corresponding or similar elements throughout the several views, the apparatus and method of use are illustrated.
[0044] In FIG. 1 , the array of modular components 100 with a plurality of supporting mounts is shown as being connected to and being self-supporting by the trailer hitch receiver connected to a pick-up truck. In FIG. 1A , the same array of modular components 100 with a plurality of supporting mounts is shown with additional stability introduced to the array using four stands 180 , with the stand 180 FIG. 10 connected under each of four perimeter supporting mounts.
[0045] In FIG. 2 , the array of modular components 100 with a plurality of supporting mounts 150 , 160 , and 170 is shown as being free-standing being supported by four stands 180 stabilizing the array.
[0046] In FIG. 2 , the central point is the base T 110 component, a “t” module. The next component to the right is the extension 120 component, an extension module, connected to the right receiver port of the base T 110 component. The tongue of the extension 120 , is inserted into the receiver of the base T 110 . The next component to the right is another base T 110 component connected to the prior extension 120 component. The tongue of the base T 110 component is inserted into the receiver port of the extension 120 component. This configuration can be repeated to create an array of components suitable to the user's preference.
[0047] Next, the elbow 130 component is inserted into the center port of prior base T 110 component. The function of the elbow 130 is to change direction of the array. The elbow 130 can be inserted to turn the direction of the next component left or right, or if the elbow 130 is rotated 90 degrees, turn the direction vertical. Each elbow 130 component has a tongue which inserts into the prior receiver of an extension 120 component, or a base T component 110 as shown here.
[0048] The next component shown is a short 150 support mount connected to the prior elbow 130 component. The short 150 support mount is illustrative of any number of commercially available mounting supports sized to fit a standard trailer hitch receiver.
[0049] Returning to the base T component 110 which the elbow 130 is connected to the center port, FIG. 2 shows two extension 120 components, one each connected to each the right and left port of the base T 110 component. For each extension 120 component, the tongue is inserted into the respective right and left receiver port of the base T 110 component.
[0050] Looking at the extension 120 component connected to the right receiver port of the base T component, a tall 170 support mount is shown. A stand 180 is positioned underneath the base of the tall 170 support mount. Looking at the extension 120 component connected to the left receiver port of the base T 110 component, a riser 140 component is connected to the extension 120 component by inserting the tongue of the riser 140 into the receiver of the extension 120 . A stand 180 is positioned underneath the base of the Riser 140 support mount to provide additional stability when desired. The riser 140 component has a built in elbow to change from the horizontal direction of the extension 120 component to the vertical direction of the riser 140 . The user may utilize the riser 140 component as a long extension elbow by rotating the riser 140 90 degrees.
[0051] FIG. 2 shows next an elbow 130 component connected to the riser 140 component. The tongue of the elbow 130 component is inserted into the receiver of the riser 140 component. Next, a long 160 support mount is shown as being connected to the elbow 130 . The tongue of the long 160 support mount is inserted into the receiver of the elbow 130 component.
[0052] Universally, the interconnection of components described above illustrate the present embodiment and versatility of the array of modular components 100 presented herein. The present embodiment shown illustrates how the components 110 , 120 , 130 , 140 , 150 , 160 , 170 and 180 can be sequenced to form the array of modular components 100 . Also shown and described above is the inherent flexibility to rotate any component 90 degrees to change direction and elevation.
[0053] Returning to the central point, which is the base T 110 component inserted into the trailer hitch receiver connect to the vehicle, a “t” module, the next component to the left is the extension 120 connected to the left receiver port of the base T 110 component. The tongue of the extension 120 , an extension module, is inserted into the left receiver of the base T 110 . The next component to the left is another base T 110 component connected to the prior extension 120 component. The tongue of the base T 110 component is inserted into the receiver port of the extension 120 component. This configuration can be repeated to create an array of components suitable to the user's preference.
[0054] The next component shown is a long 160 support mount connected to the center port of the prior base T 100 component. The long 160 support mount is illustrative of any number of commercially available mounting supports sized to fit a standard trailer hitch receiver.
[0055] Returning to the base T component 110 , FIG. 2 , left branch, two extension 120 components are shown, one each connected to each the right and left port of the base T 110 component. For each extension 120 component, the tongue is inserted into the left and right receiver port of the Base T 110 component, respectively.
[0056] Looking at the extension 120 component connected to the left receiver port of the base T component, a short 150 support mount is shown. A stand 180 is positioned underneath the base of the short 150 support mount. Looking at the extension 120 component connected to the right receiver port of the base T 110 component, a tall 170 support mount is connected to the extension 120 component by inserting the tongue of the tall 170 support mount into the receiver of the extension 120 . A stand 180 is positioned underneath the base of the tall 170 support mount to provide additional stability when desired.
[0057] Such versatility allows the user to configure the array of modular components 100 to occupy space behind the rear of a pick-up truck as shown in FIG. 1 or to be deployed free-standing as shown in FIG. 2 . The user may decide to extend the array of modular components to a length sufficient to support all attached mast supports outside the wheel base of the vehicle, inside the wheel-base of the vehicle, or even above the vehicle, as shown in FIG. 1 , above and inside the perimeter of the bed of the pick-up truck. In FIG. 1A , the same array of modular components is shown with four additional stand 180 components to illustrate how the user can stabilize the array under extreme uses. Other stabilizing techniques can be employed including, but not limited to using guy ropes, weights, or cross bracing.
[0058] In FIG. 2 , a standard hitch-pin 125 , alternatively a ⅝″ threaded bolt washer and nut, may be utilized to pin the modular components through the receiver and tongue coupling.
[0059] FIG. 3 illustrates the base T 110 component, the “t” module, comprised of the outside base 10 , cross member 11 , top 12 and plate 13 . Hole pair 15 a and 15 b is shown which is utilized to pin the outside base 10 element receiver with the tongue 20 element inserted. The tongue element 20 is made from the smaller inside square tubing with hole pairs 24 - 28 a and 24 - 28 b FIG. 4 positioned laterally along the span of the tongue 20 element.
[0060] FIG. 3 illustrates the cross member 11 element permanently positioned at the top of the outside base 10 element. Hole pairs 16 a and 16 b, 17 a and 17 b are positioned at the right and left ends of the cross member 11 element. These hole pairs are utilized to pin other components connected to the cross member 11 element of the base T component.
[0061] FIG. 3 also illustrates the top 12 element as being permanently connected to the cross member 11 element. Hole pairs 14 a and 14 b are utilized to pin other components connected to the top of the base T 110 component.
[0062] In FIG. 3 , plate 13 element is permanently positioned to the outside base 10 element, both left and right sides of the cross member 11 element and the top 12 element to provide structural strength to the cross member 11 element welds to the outside base 10 element and the top 12 element of the base T 110 component.
[0063] The hole pairs 24 a - 28 a and 24 b - 28 b FIG. 4 of the tongue 20 element provide versatility to the base T 110 component FIG. 3 and the extension 120 Component FIG. 4 by allowing the user to adjust the insertion depth of the tongue 20 element into the outside base 10 element of the base T 110 Component FIG. 3 and the outside sleeve 21 element of the extension 120 component FIG. 4 . This adjustability allows the base T 110 and extension 120 components to be longer or shorter depending on the dimension and clearances of the array of modular component 100 desired. This adjustable range provides for spatial separation of support mounts; horizontal and vertical RF isolation, EMI isolation and antenna pattern interference mitigation; and balancing of weight supported by the array of modular components 100 .
[0064] In FIG. 4 , the extension 120 component is illustrated. Here, the outside sleeve 21 element is shown. The tongue 20 element is also shown as being inserted into the lower receiver of the outside sleeve 21 element. Hole pair 22 a - 22 b of the outside sleeve 21 element is used in conjunction with hole pairs 24 - 28 a and 24 - 28 b of the tongue 20 element to secure the length of the extension 120 component. Hole pair 23 a - 23 b of the outside sleeve 21 element is used to pin the tongue of other elements or components inserted into the receiver of the extension 120 component.
[0065] In FIG. 5 , the elbow 130 component is shown. The elbow 130 component is made by fitting smaller square tubing to form the tongue 30 element at a right angle with larger outside tubing to form the receiver 31 element. Hole pairs 34 a - 34 b, 35 a - 35 b are positioned to be utilized to pin other components inserted into the receiver 31 element of the elbow 130 component. Hole pairs 32 a - 32 b, 33 a - 33 b are positioned to be utilized to pin the tongue 30 element to other receiver of components which the elbow 130 component is inserted.
[0066] In FIG. 6 , the riser 140 component is shown. The riser 140 component is made by fitting smaller square tubing to form the tongue 40 element at a right angle with larger and longer outside tubing to form the receiver 41 element. Hole pair 43 a - 43 b of the receiver 41 element is positioned to be utilized to pin other components inserted into the receiver 41 element of the riser 140 component. Hole pair 42 a - 42 b of the tongue 40 element is positioned to be utilized to pin other receiver of components which the riser 140 component is inserted. Additional hole pairs may be added to increase the versatility providing for the rotation of the riser to meet other configuration requirements. Hole 44 a and 44 b are provided to allow connection using a Stand 180 FIG. 10 to provide additional stability when desired.
[0067] FIG. 7 illustrates the short 150 support mount. This component is made using the smaller square tubing to for the tongue 50 element, which is joined at a right angle with the round receiver 51 element. Hole pair 53 a - 53 b is positioned to pin the tongue 50 element with the other component receivers which the short 150 support mount is inserted. The corner brace 52 element is shown as additional support between the tongue 50 element and the round receiver 51 element. Hole 54 is positioned at the bottom of the round receiver 51 element to facilitate draining and/or to connect the Stand 180 for support as shown in FIG. 2 .
[0068] As an additional note, FIG. 7 illustrates the short 150 support mount as a fixed 90-degree fixture. The present embodiment does not limit the support mount to a ridged fixture. If desired, the corner brace 52 element can be detachable from the round receiver 51 element which could pivot on hinges attached to the tongue 50 element and the round receiver 51 element.
[0069] FIG. 8 illustrates the long 160 support mount. This component is made using longer smaller square tubing to for the tongue 60 element, which is joined at a right angle with the round receiver 51 element. Hole pair 61 a - 61 b is positioned to pin the tongue 60 element with the other component receivers which the long 160 support mount is inserted. The corner brace 52 element is shown as additional support between the tongue 60 element and the round receiver 51 element. Hole 54 is shown as described above.
[0070] FIG. 9 illustrates the tall 170 support mount. This component is made using longer smaller square tubing to for the tongue 60 element, which is joined at a right angle with the round receiver 70 element, which is taller. Hole pair 61 a - 61 b is positioned to pin the tongue 60 element with the other component receivers which the tall 170 support mount is inserted. The corner brace 52 element is shown as additional support between the tongue 60 element and the round receiver 70 element. Hole 71 is shown to perform drainage and support functions as described for Hole 54 above.
[0071] In FIG. 7-8 , and FIG. 9 , hole 54 and hole 71 respectively illustrates the location where the stand 180 inserts to stabilize the array of modular components. Additionally, these holes allow the support mounts to drain.
[0072] In FIG. 10 , the stand 180 is shown. The stand 180 is comprised of a solid round bar 181 element with a shoulder 182 suitable to inserting the shaft of the solid round bar 181 element into hole 54 or 71 of the support stands 150 , 160 or 170 or into the hole 44 a or 44 b of the riser 140 . Hole pairs 185 a - e and 186 a - e are positioned along the lower shaft of the solid round bar 181 element. A stand sleeve 183 element with hole pairs 187 a - e and 188 a - e is inserted into the collar 184 a attached to the stand base 184 . The collar 184 a is secure to and supported by corner braces 184 b. The hole pairs positioned on the solid round bar 181 element and the stand sleeve 183 element are utilized to adjust the height of the Stand 180 .
[0073] This versatility described above to arrange the assembly sequence of the various modular components allows the user to deploy the array in a wide variety of configurations which illustrates the versatility of the present embodiment.
[0074] The present embodiment is not restricted in use or application to round support system similar to what is described herein. Addition supports for televisions, BBQ grills, satellite antennas, flog poles, foot-steps, banner supports and other commercially available or custom made support mounts are feasible and would not diminish the utilize of the embodiment presented herein. Nor is the present embodiment restricted in use or application to trailer hitch receivers affixed to a vehicle. The trailer hitch receiver utilized to support the central base T or central extension components could be affixed to a building structure, post in the ground, trailer, tractor or any other plausible mounting solution.
[0075] It may be advantageous to set forth definitions of certain words and phrases used in this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
[0076] What has been described above includes examples of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art can recognize that many further combinations and permutations of such matter are possible. Accordingly, the claimed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
[0077] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.
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A modular apparatus to enable users to multiply the number of objects being supported by a single trailer hitch receiver which installs into a trailer hitch receiver, which can be connected to an automobile, or which rests independently on stands positioned underneath the apparatus, forming a three dimensional array of interconnected mounting brackets used to support objects above the ground with a plurality of configurations possible wherein the user can vary the width, length and height of the array by adjusting the modular components within the limits of the modular component.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application of U.S. Ser. No. 12/142,957, filed Jun. 20, 2008, and entitled “Arrangement for Controlling Fluid Jets Injected into a Fluid Stream,” which is a divisional application of U.S. Ser. No. 11/131,976, filed May 18, 2005, now U.S. Pat. No. 7,418,827. The content of these applications is incorporated herein by reference it its entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to the mixing of fluid flow streams and, more particularly to the injection of a primary fluid into a secondary fluid cross-stream, as found in, but not limited to, jet engine combustion chambers, jet engine bleed-air discharge nozzles, and jet-engine thrust vectoring nozzles.
[0003] A fluid jet injected essentially normally to a fluid cross-stream is an important phenomenon that is ubiquitous in industrial processes involving mixing and dispersion of one fluid stream into another. For example, the “jet in cross-flow” phenomenon, as it is commonly called, dictates the efficiency of the mixing process between different gases in a jet combustor, controlling the rates of chemical reactions, NO x and soot formation, and unwanted temperature non-uniformity of gases impinging on the turbine blades.
[0004] The jet-in-cross-flow phenomenon is also present at the discharge port of high temperature compressor bleed-air into the fan steam of jet engines, as well as in fuel injector nozzles on afterburners and in fluidic thrust-vectoring devices.
[0005] Herein, we define as “primary fluid” the fluid of the injected jet, and as “secondary fluid” the fluid of the cross-stream. The two main characteristics of the jet-in-cross-flow phenomenon are:
a) the penetration depth of the primary fluid plume into the secondary fluid stream, and b) the rate of dispersion and mixing of the primary fluid plume into the secondary fluid stream.
[0008] Comprehensive parametric studies of multiple round jets to optimize crossflow mixing performance have been reported since the early '70s, the most general and applicable to subsonic crossflow mixing in a confined duct being reported by J. D. Holdeman at NASA (Holdeman, J. D., “Mixing of Multiple Jets with a Confined Subsonic Crossflow”, Prog. Energy Combust. Sci., Vol. 19, pp. 31-70, 1993.). Those studies, both numerical and experimental, developed correlating expression to optimize gas turbine combustor pattern factor. The primary result was that the jet-to-mainstream momentum-flux ratio was the most significant flow variable and that mixing was similar, independent of orifice diameter, when the orifice spacing and the square-root of the momentum-flux were inversely proportional. More recent efforts at Darmstadt (Doerr, Th., Blomeyer, M. M., and Hennecke, D. K., “Optimization of Multiple Jets Mixing with a Confined Crossflow”, ASME-96-GT-453, 1996 and Blomeyer, M. M., Krautkremer, B. H., Hennecke, D. K., “Optimization of Mixing for Two-sided Injection from Opposed Rows of Staggered Jets into a Confined Crossflow”, ASME-96-GT-453, 1996.) further studied the optimization of round jet configurations for gas turbine applications.
[0009] Although optimized round jets provide control of pattern factor, reduction of NO x emissions could be attained by more rapid mixing in the combustion chamber. Since axisymmetric coflow configurations on non-circular orifices, such as an ellipse, had been shown to increase entrainment relative to a circular jet (Ho, C-M and Gutmark, E, “Vortex Induction and Mass Entrainment in a Small-Aspect-Ration Elliptic Jet”, J. Fluid Mech., Vol. 179, pp. 383-405, 1987 and Gutmark, E. J. and Grinstein, F. F., “Flow Control with Noncircular Jets”, Annual Rev Fluid Mech., Vol. 11, pp. 239-272, 1999.), similar orifices were considered for NO x reduction in crossflow configurations during NASA's High Speed Research program in the early '90s. Liscinsky (Liscinsky, D. S., True, B., and Holdeman, J. D., “Mixing Characteristics of Directly Opposed Rows of Jets Injected Normal to a Crossflow in a Rectangular Duct”, AIAA-94-0218, 1994.) and Bain (Bain, D. B., Smith, C. E., and Holdeman, J. D., “CFD Assessment of Orifice Aspect Ratio and Mass Flow Ration on Jet Mixing in Rectangular Ducts”, AIAA-94-0218, 1994.) using parallel-sided orifices (squares, rectangles and round-ended slots) launched an investigation to improve upon the mixing performance of round jets. Optimizing correlations were developed but a significant enhancement in mixing relative to round holes was not achieved. The slots were also rotated relative to the mainstream to control jet trajectory but mixing enhancement was not observed for optimized configurations. Concurrent investigations in cylindrical ducts were performed experimentally and numerically by Sowa (Sowa, W. A., Kroll, J. T., and Samuelsen, G. S., “Optimization of Orifice Geometry for Crossflow Mixing in a Cylindrical Duct”, AIAA-94-0219, 1994.) and numerically by Oeschle (Oeschle, V. L., Mongia, H. C., and Holdeman, J. D., “An Analytical Study of Jet Mixing in a Cylindrical Duct”, AIAa-93-2043, 1993.) also without significant mixing improvement relative to circular jets.
[0010] Detailed single jet studies of symmetric noncircular orifice shapes in crossflow were also performed in the late 90s (Liscinsky, D. S., True, B., and Holdeman, J. D., “Crossflow Mixing of Noncircular Jets”, Journal of Propulsion and Power, Vol. 12, No. 2, pp. 225-230, 1996 and Zamn, KBMQ, “Effect of Delta Tabs on Mixing and Axis Switching in Jets from Axisymmetric Nozzles”, AIAA-94-0186, 1994.). These investigations also included the use of tabs placed at the nozzle exit as vortex generators. Azimuthal non-uniformity at the jet inlet is naturally unstable and introduces streamwise vorticity which increases entrainment for axisymmetric flows, however in a crossflow configuration the vorticity field is dominated by the bending imposed by the mainstream. The vorticity generated by the initial jet condition was found to be insignificant and appreciable mixing enhancement relative to a circular jet was not observed.
[0011] In summary, a round orifice is the most commonly used shape from which the primary fluid emanates, leading to a jet of essentially cylindrical shape in the vicinity of the orifice. This cylindrical shape is rapidly bent by the secondary cross-stream into a plume oriented with the cross-stream direction. Prior-art investigations have been directed at discovering improved orifice shapes in the hope of passively improving either or both of the plum penetration and dispersion and mixing. While slanted slots have provided some reduction in penetration depth, no shapes have been reported that offer significant improvements over the round orifice shape. The lack of a mechanism for the control of plume penetration depth that is independent of the exit jet velocity is a shortcoming that forces compromises into the design of industrial systems.
[0012] Furthermore, the downstream development of the plume from prior-art non-circular orifices is similar to that of the plume form the circular orifice. In particular, both circular and non-circular cases generated a plume characterized by a cross-sectional area of kidney-like form containing two counter-rotating vortices oriented parallel to the secondary-fluid stream direction. Far from the plume, the velocity induced by one vortex of this vortex pair is essentially cancelled by the other counter-rotating vortex of the pair. Consequently, when multiple plumes are present, the counter-rotating vortices produce a weak interaction between neighboring plumes emitted from near-by orifices, leading to relatively weak overall dispersion of the primary fluid.
[0013] It is thus desirable to have an orifice shape that leads to a strong control of primary-fluid plume penetration independent of exit jet velocity, thus allowing authoritative placement of the jet plume at a desired, predetermined depth into the secondary steam. It is also desirable to have an orifice shape leading to a plume containing a single, rather than a pair, of vortices, that allows stronger interaction between neighboring plumes.
[0014] Objects of the current invention are thus to:
1) provide a geometry for the primary-fluid orifice that leads to a strong control authority over the primary fluid plume penetration depth into the secondary stream, the penetration control being independent of exit jet velocity, and 2) provide a geometry for the primary-fluid orifice that leads to a primary fluid plume having a single dominant component of streamwise vorticity, leading to stronger plume-plume interaction and mixing.
SUMMARY OF THE INVENTION
[0017] The orifice from which the primary fluid is emitted is given a streamlined, airfoil-like shape to create (in an extruding fashion) a steamlined jet having a wing-like form in the vicinity of the orifice. The term “streamlined” refers to a body dominated by frictional drag, as opposed to pressure drag. When the wing-like jet is placed at an angle of attack in the secondary fluid cross-stream, a strong tilting force develops on the jet, much like the well known lifting force on a solid wing, causing the jet to bend away from the plane defined by the initial injection direction and the cross-stream direction. By varying the angle of attack, the magnitude of the lifting force is altered, and the penetration of the jet is strongly affected. Additionally, the lift force creates circulatory-flow (i.e. single-sided vorticity) around the jet that maintains itself far downstream of the jet orifice. Both of these effects strongly affect the penetration, mixing, and interaction of multiple fluid-wings. For a given airfoil-like orifice shape, the variation of angle of attack provides a strong control authority over the jet penetration depth. Since the angle of attack is a geometric quantity, it is independent of the exit velocity of the jet, and, thus, provides a control of jet penetration that is independent of jet exit velocity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic perspective illustration of one possible embodiment of the present invention, namely a wing-like orifice geometry.
[0019] FIG. 2 is a schematic perspective illustration of a wing-like orifice geometry, and its resulting airflow patterns.
[0020] FIG. 3 is a schematic perspective view of the embodiment shown in FIG. 1 with an included solid collar attached to the orifice.
[0021] FIG. 4 is a schematic perspective illustration of an alternative embodiment of the present invention, namely a main-wing orifice and an auxiliary flap orifice.
[0022] FIG. 5 is a schematic perspective illustration of another embodiment of the present invention, namely both circular and wing-like orifices.
[0023] FIGS. 6 a - 6 c are schematic perspective illustrations of yet another embodiment of the present invention, namely a bleed-port attachment with:
[0024] FIG. 6 a being a top view,
[0025] FIG. 6 b being the front view looking along the secondary fluid stream direction and
[0026] FIG. 6 c being a side view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] In the first embodiment of the invention as shown in FIGS. 1 and 2 , a surface 100 separates an upper region containing a secondary fluid moving essentially parallel to said plate from a lower region having a primary fluid at higher pressure than the pressure of the secondary fluid. The surface 100 could be part of any device that mixes cross-streams of fluids, such as combustion chambers, bleed air discharge nozzles and thrust vectoring nozzles of gas turbine engines.
[0028] In a jet engine combustion chamber, the primary air is combustion-free air injected into a combustion chamber and is referred to as quench air and the secondary air is air having fully or partially burned fuel and is referred to as front-end air.
[0029] In a jet engine bleed air discharge nozzle, the primary air is compressor bleed air and the secondary air is air external to the compressor (e.g. fan-stream air). In a jet engine thrust vectoring nozzle, the primary air is compressed bleed air and the secondary fluid is jet engine exhaust flow.
[0030] The direction of the secondary fluid is indicated by arrow 110 . The plate has at least one orifice 200 allowing fluid communication between the primary and secondary fluids. The orifice 200 comprises a perforation shaped with an airfoil-like form having a leading edge 205 , an upper 206 and a lower edge 207 slowly diverging to a point of maximum separation then slowly converging to a sharp cusp at the trailing edge 208 , so as to form an airfoil profile of conventional form. The imaginary line connecting the leading and trailing edge is called the chord, shown at line 209 . The orifice is oriented with the leading edge located upstream in the secondary fluid flow from the trailing edge and with the chord aligned with a predetermined angle to the secondary flow direction, the angle being indicated by the symbol a in FIG. 1 . The predetermined angle is called the angle of attack, and the combination of angle of attack and orifice shape, including the camber (camber is the curvature of the air foil center-line) of the airfoil, determines the lift force experienced by the primary fluid particles leaving the orifice, and hence determines the plume penetration. Airfoil shapes designed for low Reynolds number flows, as known in the art, are best suited. Given an airfoil shape, the angle of attack is chosen to satisfy the needs of each specific engineering application: low angles of attack when high penetration is desired, high angles of attack (essentially between 0 and 20 degrees) when low penetration is desired.
[0031] Due to the pressure difference between the primary fluid and the secondary fluid, a jet of primary fluid 210 is emitted from the orifice 200 into the secondary fluid cross-stream. The jet of primary fluid 210 inherits the airfoil cross-section of the orifice 200 and, consequently, forms a wing-like shape in the vicinity of the orifice 200 . The wing-shaped jet experiences a lateral force shown at arrow 300 which is proportional in strength to said angle of attack. The lateral force 300 brings the jet of primary flow substantially perpendicularly away from the plane defined by the direction of the primary fluid jet at the orifice and the direction of the secondary cross-stream, thereby lowering the overall penetration depth of the jet plume into the secondary cross-stream.
[0032] In the process of developing lift, a circulatory component of fluid motion, shown at arrows 310 and referred to as “circulation” within conventional airfoil theory, is established at the base of the jet of primary fluid 210 . This circulatory motion is convected with the primary fluid particles and remains with the primary fluid particles (Kelvins' theorem), as shown by arrows 320 , even after the jet has lost its wing-like shape and has reoriented itself in the cross-stream direction. The circulatory motion of the primary fluid particles establishes a single dominant component of streamwise voracity in the jet plume (i.e. avoiding the two counter-rotating vortices produced by conventional orifice shapes). Thus, the circulating movement of air, as shown by the arrows 310 , is dependent on the airfoil shape of the primary fluid flow 210 and is generally proportional to the angle of attack α. In turn, the force, as shown by the arrow 300 , is generally proportional to the circulatory motion 310 and will effect both the penetration depth and the rate of dispersion for the primary fluid flow 210 into the secondary fluid flow 110 . Generally, a larger attack angle α will result in less penetration but greater dispersion. It is thus necessary to choose an appropriate attack angle that will bring about an optimum balance of penetration and dispersion. As a general guideline, it is estimated that an airfoil shaped orifice having an angle of attack of α=0°, provides a 30% greater penetration than a round orifice of the same area. Further if the same airfoil shaped orifice is presented so as to have an angle of attack of α=10°, then the penetration is estimated to be about half (50%) that of a corresponding round orifice, but with much better dispersion characteristics. As further guidance, an attack angle in the range of negative 5 to positive 25 degrees is suggested for a jet engine combustion chamber, and an attack angle of 5 to 15 degrees (as needed to place the plume away from the nacelle surfaces at downstream locations) is suggested for a jet engine bleed air discharge nozzle.
[0033] In reference to FIG. 3 , a collar, or solid sleeve 220 , is added to the perimeter of orifice 200 to “lift” the orifice off the plane 100 . Essentially, the collar gives the orifice an extension into the third dimension. The collar is beneficial, for example, in those cases when the flow through the orifice is reduced to a trickle and the trickling fluid must avoid contact with the plane 100 . Such a case exists, for example, for the bleed-air port on jet engines, wherein the trickle is caused by an incomplete closure of the bleed-air valve, and the hot trickling air can damage the nacelle when contacting the nacelle surface.
[0034] In another embodiment of the invention as shown in FIG. 4 , the orifice comprises a first and second opening. The first opening, shown at 201 , forms the “main wing” jet and the second opening, shown at 202 , forms an auxiliary flap jet whose role is to increase the efficiency and the lift force experienced by the main-wing jet, much like a conventional trailing edge flap aids the performance of the main wing at lower wing translational velocities. Furthermore, the close proximity of the main-wing jet to the flap jet creates a strong interaction between the downstream plume 330 from the main opening and the downstream plume 340 from the flap opening. This interaction leads to increased mixing of primary fluid with the secondary fluid.
[0035] Another embodiment of the invention is shown in FIG. 5 which relates to a combustor application, wherein it is desired to provide a substantially increased amount and penetration of primary airflow. For example, where the combustor maybe constrained in length and there isn't sufficient surface to rely on only airfoil shaped orifices, it maybe advantageous to use a combination of orifice shapes as shown.
[0036] In the FIG. 5 embodiment, a surface 100 of a combustor liner separates an upper region (i.e. the combustion zone) containing a secondary fluid moving parallel to said plate from a lower region having a primary fluid at higher pressure than the pressure of the secondary fluid. The secondary fluid direction is indicated by arrow 110 . The plate has a pattern of orifices for communication between the primary and secondary fluid, the pattern comprising a mixture of wing-like orifices and non-wing-like orifices. Although other shapes could be used, FIG. 5 shows the non-wing-like orifices having a circular shape. A part of this pattern is shown in FIG. 5 wherein circular orifices are shown at 400 and orifices having a wing-like streamlined cross-section are shown at 410 . Examples or orifice patterns maybe the alternating rows of circles and wings, as shown in FIG. 5 , or maybe a checkerboard pattern of circles and wings (not shown), or other patterns. A jet from circular holes forms a downstream plume of kidney-shaped cross sections, as indicated by 420 that is located away from the plate 100 , leaving a volume of secondary fluid below said plume that is not active in the mixing of the primary fluid with the secondary fluid. The juxtaposition of circular orifices with wing-like orifices, each at a predetermined angle of attack, allows a positioning of the downstream plumes from the wing-like orifices 430 below the downstream plumes from the circular orifices 420 . This produces mixing between the primary fluid and the secondary fluid over a greater volume of secondary fluid above the plate. As a further benefit, the pressure-drop between primary and secondary fluids is less than the pressure drop associated with an orifice pattern consisting of large and small diameter circular holes, wherein the small-diameter holes are used to generate an overall plume distribution that approximates the distribution generated by the airfoil-shaped orifices.
[0037] A further embodiment of the invention is shown in FIGS. 6 a , 6 b and 6 c wherein, in a bleed port attachment application, the authority over plume penetration is used to construct a bleed-port attachment that positions and shapes the exhausted bleed-air plume into a desired form and trajectory. A surface 100 ( FIG. 6 ) separates an upper region (e.g. the fan duct) containing a secondary fluid (namely bypass air) moving parallel to said plate from a lower region (e.g. ducts in communication with the compressor section of the gas turbine engine) having a primary fluid (namely core engine air) at higher pressure than the pressure of the secondary fluid. The attachment comprises at least two wing-shaped orifices with collars, and preferably four orifices with collars oriented with an angle of attack with respect to the secondary fluid stream direction, indicated by arrow 110 in FIG. 6 a . The orifices and collars provide communication between the primary and secondary fluids, and the pressure difference between the primary and secondary fluids generates a jet of primary fluid from each orifice, the jet having an airfoil-like cross section and a wing-like form in the vicinity of each orifice. When the primary fluid plume must be spread over a wide space within the secondary fluid stream, at least two orifices with collars are positioned with opposite directed lift directions, such as collars 602 and 603 in FIG. 6 , such that the corresponding emitted plumes 702 and 703 spread laterally away from one another as each plume convects in the secondary cross-stream flow. The angle of attack of the orifices plus collars 602 and 603 is increased or decreased to reduce or increase plume penetration into the secondary stream, as desired.
[0038] When four orifices with collars are used, the outer two collars 601 and 604 are each oriented to give a lift directed in the same direction as that of the neighboring inner collar, and the outer two collars 601 , 604 are preferably titled away from the perpendicular direction to plane 100 to further assist the lateral displacement of associated plumes 701 and 704 . When the plumes emitted from the inner orifices 601 , 602 penetrate further into the secondary air stream than the plumes from the outer orifices 601 , 604 , and an essentially equal penetration of plumes from all four orifices is desired, the collars of the inner two orifices 602 , 603 are preferably lower in height than the height of the outer collars 601 , 604 .
[0039] When an asymmetric plume development downstream of the bleed port is desired, the lift direction of same, or all, of the orifices and collars maybe oriented toward the desired side of the bleed port (asymmetric bleed-port attachment not shown).
[0040] Guide vanes 620 extend from the bleed-port attachment into the piping feeding the bleed-port to partition the primary fluid flow into parts appropriate for each orifice. Furthermore, the guide vanes help prevent undesired unsteadiness in the fluid emitted from each orifice.
[0041] In addition to the advantages and benefits of the present invention as discussed hereinabove, the reduction in NO x gas resulting from lowered operating temperatures should be mentioned. In this regard, it should be recognized that, in a jet engine combustion chamber, the secondary fluid contains combustible fuel as it approaches and passes around the plume being introduced by the primary fluid. When this plume is substantially round, as will be the case for round orifices, there will be a substantial wake created on the downstream side of the primary fluid plume. The entrained fuel tends to remain within that wake and its temperature is, accordingly, caused to rise to the point where NO x gases are formed. This is to be contrasted with the rather sharp trailing edge of a primary fluid plume resulting from an airfoil shaped orifice. Here, there is very little, if any, wake created at the trailing edge and therefore the fuel is not trapped in this area, but continues to flow downstream and remain at temperatures that are not likely to cause NO x formation.
[0042] While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail maybe effected therein without departing from the scope of the invention as defined by the claims.
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In an air mixing arrangement wherein a primary fluid is introduced through an opening in a wall to be mixed with a secondary fluid flowing along the wall surface, the opening is airfoil shaped with its leading edge being orientated at an attack angle with respect to the secondary fluid flow stream so as to thereby enhance the penetration and dispersion of the primary fluid stream into the secondary fluid stream. The airfoil shaped opening is selectively positioned such that its angle of attack provides the desired lift to optimize the mixing of the two streams for the particular application. In one embodiment, a collar is provided around the opening to prevent the secondary fluid from contacting the surface of the wall during certain conditions of operation. Multiple openings maybe used such as the combination of a larger airfoil shaped opening with a smaller airfoil shaped opened positioned downstream thereof, or a round shaped opening placed upstream of an airfoil shaped opening. Pairs of openings and associated collars maybe placed in symmetric relationship so as to promote mixing in particular applications, and nozzles maybe placed on the inner side of wall to enhance the flow characteristics of the primary fluid.
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RELATED APPLICATIONS
[0001] This application is a divisional of co-pending application Ser. No. 09/693,272 filed Oct. 20, 2000, which is a continuation-in-part of U.S. Provisional Patent Application Ser. No. 60/160,891, filed Oct. 22, 1999, and entitled “Facet Arthroplasty Devices and Methods,” which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to devices and surgical methods for the treatment of various types of spinal pathologies. More specifically, the present invention is directed to several different types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments which may be used to perform the surgical procedures.
BACKGROUND OF THE INVENTION
[0003] Back pain is a common human ailment. In fact, approximately 50% of persons who are over 60 years old suffer from lower back pain. Although many incidences of back pain are due to sprains or muscle strains which tend to be self-limited, some back pain is the result of more chronic fibromuscular, osteoarthritic, or ankylosing spondolytic processes of the lumbosacral area. Particularly in the population of over 50 year olds, and most commonly in women, degenerative spine diseases such as degenerative spondylolisthesis and spinal stenosis occurs in a high percentage of the population. Iida, et al, 1989.
[0004] Degenerative changes of the adult spine have traditionally been determined to be the result of the interrelationship of the three joint complex; the disk and the two facet joints. Degenerative changes in the disc lead to arthritic changes in the facet joint and vice versa. See Farfan and Sullivan, 1967; see also Farfan, 1969; see also Farfan, 1980.
[0005] One cadaver study of 19 cadavers with degenerative spondylolisthesis showed that facet degeneration was more advanced than disc degeneration in all but two cases. Farfan. In mild spondylolisthetic cases, the slip appeared to be primarily the result of predominantly unilateral facet subluxation. Other studies into degenerative changes of the spine have revealed extensive contribution of facet joint degeneration to degenerative spinal pathologies such as degenerative spondylolisthesis, central and lateral stenosis, degenerative scoliosis, and kypho-scoliosis, at all levels of the lumbar spine. See Kirkaldy-Willis et al, 1978; see also Rosenberg, 1975.
[0006] It has been determined that facet joint degeneration particularly contributes to degenerative spinal pathologies in levels of the lumbar spine with sagittally oriented facet joints, i.e. the L4-L5 level.
[0007] When intractable pain or other neurologic involvement results from adult degenerative spine diseases, such as the ones described above, surgical procedures may become necessary. Traditionally, the surgical management of disease such as spinal stenosis consisted of decompressive laminectomy alone. Herkowitz, et al, The Diagnosis and Management of Degenerative Lumber Spondylolisthesis, 1998. Wide decompressive laminectomies remove the entire lamina, and the marginal osteophytes around the facet joint. Because a lot of degenerative spine disease has been demonstrated to be caused by facet joint degeneration or disease, this procedure removes unnecessary bone from the lamina and insufficient bone from the facet joint.
[0008] Furthermore, although patients with one or two levels of spinal stenosis tend to do reasonably well with just a one to two level wide decompressive laminectomy, patients whose spinal stenosis is associated with degenerative spondylolisthesis have not seen good results. Lombardi, 1985. Some studies reported a 65% increase in degree of spondylolisthesis in patients treated with wide decompressive laminectomy. See Johnson et al; see also White and Wiltse. The increase in spinal slippage especially increased in patients treated with three or more levels of decompression, particularly in patients with radical laminectomies where all of the facet joints were removed.
[0009] To reduce the occurrence of increased spondylolisthesis resulting from decompressive laminectomy, surgeons have been combining laminectomies, particularly in patients with three or more levels of decompression, with multi-level arthrodesis. Although patients who undergo concomitant arthrodesis do demonstrate a significantly better outcome with less chance of further vertebral slippage after laminectomy, arthrodesis poses problems of its own. Aside from the occurrence of further spondylolisthesis in some patients, additional effects include non-unions, slow rate of fusion even with autografts, and significant morbidity at the graft donor site. Furthermore, even if the fusion is successful, joint motion is totally eliminated at the fusion site, creating additional stress on healthy segments of the spine which can lead to disc degeneration, herniation, instability spondylolysis, and facet joint arthritis in the healthy segments.
[0010] An alternative to spinal fusion has been the use of an invertebral disc prosthesis. There are at least 56 artificial disc designs which have been patented or identified as being investigated. McMillin C. R. and Steffee A. D., 20th Annual Meeting of the Society for Biomaterials (abstract)(1994). Although different designs achieve different levels of success with patients, disc replacement mainly helps patients with injured or diseased discs; disc replacement does not address spine pathologies such as spondylolisthesis and spinal stenosis caused by facet joint degeneration or disease.
SUMMARY OF THE INVENTION
[0011] There is a need in the field for prostheses and prosthetic systems to replace injured and/or diseased facet joints, which cause, or are a result of, various spinal diseases. There is also a need for surgical methods to install such prostheses. There is also a need for prostheses and prosthetic systems to replace spinal fusion procedures.
[0012] The present invention overcomes the problems and disadvantages associated with current strategies and designs in various treatments for adult spine diseases. The present inventive spinal arthroplastic systems avoid the problems of spine stiffness, increased loads on unfused levels, and predictable failure rates associated with spinal arthrodesis.
[0013] The present invention pertains to spinal prostheses designed to replace facet joints and/or part of the lamina at virtually all spinal levels including L1-L2, L2-L3, L3-L4, L4-L5, L5-S-1, T11-T12, and T12-L1. Various types of joint replacement prostheses are described for treating different types of spinal problems.
[0014] One aspect of the invention provides a facet prosthesis, which suitable for use in virtually all levels of the spine, including all lumbar levels, lower thoracic levels, and the first sacral level. The facet prosthesis may comprise, e.g., a body which attaches to a pedicle and includes a surface defining a facet.
[0015] Another aspect of the invention provides a bilateral facet arthroplasty system. The bilateral facet arthroplasty system may comprise, e.g., an inferior lamina/facet prosthesis that spans the distance from one inferior facet joint to another and replaces both inferior facet segments and any inferior section of a lamina which has been cut. The bilateral facet arthroplasty system may also comprise, e.g., facet prostheses which have replaced the superior facets to form a complete prosthetic facet joint with the inferior facet prosthesis.
[0016] Another aspect of the invention provides a hemi-lamina/facet prosthesis, which may replace parts of a lamina and inferior facet which have been removed in a hemiarthroplasty with or without wide decompressive laminectomy.
[0017] Another aspect of the invention provides surgical procedures for performing replacements of various facets and lamina in the spine, as well as surgical instruments for facilitating performance of the disclosed surgical procedures, including spinal fusion.
[0018] Another aspect of the invention allows sequential replacements of all facet joints from S1 to T11, allowing for motion on all levels.
[0019] Features and advantages of the inventions are set forth in the following Description and Drawings, as well as in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a lateral view of a spine with degenerative spondylolisthesis at L4-L5;
[0021] FIG. 2 is a front view of a universal facet replacement prosthesis;
[0022] FIGS. 2A, 2B , and 2 C are view of an alternative embodiment of a universal facet replacement prosthesis;
[0023] FIG. 3 is a lateral view of a spine with a superior universal facet prosthesis installed in a L5 vertebra;
[0024] FIG. 4 is a superior view of a L5 vertebra with an installed superior universal facet prosthesis;
[0025] FIG. 5 is a superior view of a L5 vertebra depicting removal of the prominent bone of the superior articular process;
[0026] FIG. 6 is a diagram illustrating the trimming of the superior facet to decompress a nerve root prior to reaming;
[0027] FIG. 7 is a superior view of a L5 vertebra depicting the reaming of the facet into the pedicle;
[0028] FIG. 8 is a front view of a facet reamer;
[0029] FIG. 9 is a superior view of a vertebral body depicting broaching an opening into a vertebral body;
[0030] FIG. 10 is a superior view of a vertebral body depicting two universal facet prostheses which have been installed in a vertebral body to form two superior facets;
[0031] FIG. 11 is a posterior view of a spine depicting an installed inferior lamina/facet prosthesis;
[0032] FIG. 12 is a superior view of a vertebral body depicting complete prosthetic facet joints comprising an inferior lamina/facet prosthesis and two superior universal facet prostheses;
[0033] FIG. 13 is a lateral view of an installed complete prosthetic facet joint;
[0034] FIG. 14 is a superior view of a vertebral body depicting sagittally oriented arthritic facets with lateral stenosis;
[0035] FIG. 15 is a superior view of a vertebral body depicting removal of the inferior one eighth of the spinous process;
[0036] FIG. 16 is a superior view of a vertebral body after an inferior lamina/facet resection;
[0037] FIG. 17 is a posterior view of a spine at an L4-L5 showing a spinous process resection line and inferior facet resection line;
[0038] FIG. 18 is a posterior view of an L4-L5 after part of the lamina and inferior facets have been removed, showing an installed universal facet prosthesis;
[0039] FIG. 19 is a posterior view of an L4-L5 after part of the lamina and inferior facets have been removed with an alternative V-type laminal cut, showing an installed universal facet prosthesis;
[0040] FIG. 20 is a posterior view of a L4 vertebra with an alternative shaped inferior lamina/facet prosthesis installed over a V-type laminal cut;
[0041] FIG. 21 is a posterior view of one embodiment of an installed hemi-lamina/facet prosthesis of the present invention;
[0042] FIG. 22 is a front view of one embodiment of a hemi-lamina/facet prosthesis of the present invention;
[0043] FIG. 23 is a posterior view of a spine, at an L4-L5 joint which has undergone hemiarthroplasty with wide decompressive laminectomy, with two base members of a hemi-lamina/facet prosthesis in the process of being installed onto the L4-L5;
[0044] FIG. 24 is a posterior view of one embodiment of an installed hemi-lamina/facet prosthesis of the present invention;
[0045] FIG. 25 is a posterior view of one embodiment of an installed hemi-lamina/facet prosthesis of the present invention;
[0046] FIG. 26 is a posterior view of the L4-L5 depicting various cuts which may be made into the lamina a facets for a hemiarthroplasty with or without wide decompressive laminectomy;
[0047] FIG. 27 is a lateral view of the L4 and L5 vertebrae;
[0048] FIG. 28 is a superior view of the L4 and L5 vertebrae in a separated condition;
[0049] FIG. 29 is a front elevation view of a single-side prosthesis that embodies the feature of the invention;
[0050] FIG. 30 is a side elevation view of the prosthesis shown in FIG. 29 ;
[0051] FIG. 31 is a lateral view of the L3, L4, and L5 vertebrae, with the prosthesis shown in FIG. 29 secured to the L4 vertebral body;
[0052] FIG. 32 is a lateral view of the L3 and L4 vertebrae, with a link secured to the L4 vertebral body;
[0053] FIG. 33 is a lateral view of the L3 and L4 vertebrae, with a link secured to the L4 vertebral body;
[0054] FIG. 34 is a front elevation view of another single-side facet prosthesis that embodies the feature of the invention;
[0055] FIG. 35 is a lateral view of the L3 and L4 vertebrae, with the prosthesis shown in FIG. 34 secured to the L4 vertebral body;
[0056] FIG. 36 is a front elevation view of a double-side facet joint link assembly that embodies the feature of the invention, being formed of two criss-crossing, mating link bodies;
[0057] FIGS. 37 and 38 are front elevation views of the link bodies forming the joint link assembly shown in FIG. 36 , being shown in a mutually separated condition;
[0058] FIG. 39 is a front elevation view of an alternative embodiment of a link body that, when assembled with a mating link body, forms a joint link assembly like that shown in FIG. 36 ;
[0059] FIG. 40 is a front elevation view of the double-side facet joint link assembly shown in FIG. 36 in relation to its location on a vertebral body;
[0060] FIG. 41 is a side view of a prosthesis, like that shown in FIGS. 29, 34 , or 36 , secured for use on the pedicle of a vertebral body (shown in lateral view); and
[0061] FIG. 42 is a side view of the lower end of the prosthesis shown in FIG. 41 , forming the inferior half of a facet joint, the superior half of the facet joint being formed by a superior universal facet prosthesis shown in FIG. 2 .
[0062] The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0000] I. Anatomy of Lumbar Vertebrae
[0063] FIGS. 27 and 28 show the fourth and fifth lumbar vertebrae L4 and L5, respectively, in a lateral view (while in anatomic association) and in a superior view (separately). The lumbar vertebrae (of which there are a total of five) are in the lower back, also called the “small of the back.”
[0064] As is typical with vertebrae, the vertebrae L4 and L5 are separated by an intervertebral disk 25 . The configuration of the vertebrae L4 and L5 differ somewhat, but each (like vertebrae in general) includes a vertebral body 10 , which is the anterior, massive part of bone that gives strength to the vertebral column and supports body weight. The vertebral arch 12 is posterior to the vertebral body 10 and is formed by the right and left pedicles 14 and lamina 16 . The pedicles 14 are short, stout processes that join the vertebral arch 12 to the vertebral body 10 . The pedicles 14 project posteriorly to meet two broad flat plates of bone, called the lamina 16 .
[0065] Seven other processes arise from the vertebral arch. Three processes—the spinous process 18 and two transverse 20 processes—project from the vertebral arch 12 and afford attachments for back muscles, forming levers that help the muscles move the vertebrae. The remaining four processes, called articular processes, project superiorly from the vertebral arch (and are thus called the superior articular processes 22 ) and inferiorly from the vertebral arch (and are thus called the inferior articular processes 24 ). The superior and inferior articular processes 22 and 24 are in opposition with corresponding opposite processes of vertebrae superior and inferior adjacent to them, forming joints, called zygapophysial joints or, in short hand, the facet joints or facets. The facet joints permit gliding movement between the vertebrae L4 and L5. Facet joints are found between adjacent superior and inferior articular processes along the spinal column.
[0066] The facet joints can deteriorate or otherwise become injured or diseased, causing lack of support for the spinal column, pain, and/or difficulty in movement.
[0067] As described in this Specification, a facet joint has a superior half and an inferior half. The superior half of the joint is formed by the vertebral level below the joint, and the inferior half of the joint is formed by the vertebral level above the joint. For example, in the L4-L5 facet joint, the superior half of the joint is formed by structure on the L-5 vertebra, and the inferior half of the joint is formed by structure on the L-4 vertebra.
[0000] II. Superior Universal Facet Prosthesis
[0068] A. Structure
[0069] A superior universal facet prosthesis 330 is shown in FIG. 1 that embodies features of the invention. The prosthesis 330 is designated “superior” because it creates an artificial facet surface for the superior half of the facet joint. The artificial surface articulates with the inferior half of the facet joint. The prosthesis 330 allows for the replacement of injured, diseased and/or deteriorating components along the superior half of facet joints, to provide improved support for the spinal column.
[0070] The universal facet prosthesis 330 may be constructed and configured in various ways. The universal facet prosthesis 330 may, e.g., comprise a cup member 315 . The cup member 315 itself may be made of various materials commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, titanium alloys, chrome cobalt, surgical steel, or any other total joint replacement metal and/or ceramic, bony in-growth surface, sintered glass, artificial bone, any uncemented metal or ceramic surface, or a combination thereof. The cup member 315 may also be any appropriate shape including, but not limited to, rectangular, disc shaped, trough shaped, or cup shaped. The cup member may be fixed or anchored directly to a vertebra with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away anchors and/or wires to facilitate any future removal of the prosthesis, or a combination thereof, or any other means known in the art.
[0071] As shown in FIG. 2 , the cup member 315 is made of any joint materials commonly used in the prosthetic arts, including, but not limited to, metals, ceramics, titanium, titanium alloys, tantalum, chrome cobalt, surgical steel, bony in-growth surfaces, artificial bone, uncemented surface metals or ceramics, or any combination thereof, preferably covered with a bony in-growth surface.
[0072] In the illustrated embodiment, the cup member 315 is fixed to a stem 310 , e.g., pre-welded, or glued with a biocompatible adhesive, or removably secured using a frictional Morse taper. If desired, the stem 310 can incorporate one or more fins or ribs (not shown), extending outward from the stem 310 , which desirably reduce and/or eliminate rotation of the stem 310 once positioned within the targeted bone. In addition, the stem 310 can be cannulated, if desired, to allow the use of guide pins during insertion of the stem, as is well known in the art.
[0073] The stem 310 may itself be made of any joint materials commonly used in the prosthetic arts, including, but not limited to, metals, ceramics, titanium, titanium alloys, tantalum, chrome cobalt, surgical steel, bony in-growth surfaces, artificial bone, uncemented surface metals or ceramics, or a combination thereof. In a preferred embodiment, the stem 310 is covered with a bony in-growth surface.
[0074] In the illustrated embodiment, the cup member 315 carries a surface member, which is made of a material, e.g. polyethylene, ceramic, or metal, which provides glide and cushioning ability for any potential contacting components, such as the articular head members described below. In one embodiment (see FIG. 2 b ), the surface member 325 can be formed in a gently upwardly curving shape, similar in shape to a catcher's mitt. In another embodiment (see FIG. 2 c ), the surface member 325 is rectangular in shape with rounded corners. The cup member 315 is sized to be larger than the articulating superior half of the facet joint, to allow for motion of the joint.
[0075] The surface member 325 may be a separate component that is fixed to the cup member 315 , e.g., with a biocompatible adhesive, screws, nails, or comprise a formed part of the cup member 315 . The surface member 325 may also be held into the cup member 315 with compressive forces or friction (e.g., using a Morse taper).
[0076] As shown in FIGS. 2 a and 2 b , the stem 310 a could alternately comprise a threaded portion, such as in a pedicle screw, with the head or pedestal 315 a incorporating a depression 316 a sized to accommodate a hexagonal driver or other surgical driving tool well know in the art. In addition, the prosthesis 320 a could incorporate a lower insert 321 a sized to fit into the depression 316 a in the head 315 a . If desired, the insert 321 a could comprise a Morse taper. In this embodiment, the stem 310 a can be screwed into the bone, with the insert 321 a positioned or otherwise secure within the depression 316 a . The stem 310 a could be placed by tapping without screwing. If revision surgery is required, or some other condition required removal of the prosthesis, the insert 321 a can be removed from the stem 310 a , and the stem 310 a can subsequently be removed from the bone.
[0077] As FIG. 2 a shows, the stem 310 a can also include an enlarged projection or collar 311 a abutting the cup member 315 a . The collar 311 a serves to prevent unintended ingress of the stem 310 a further into the pedicle, beyond a desired distance.
[0078] FIG. 1 depicts a spondylolisthetic spine with slippage at the L4-L5 joint between the L4 and L5 vertebrae. FIG. 3 and FIG. 4 depict a universal facet prosthesis 330 which has been installed into an L5 vertebra 105 to replace the inferior half 305 of a facet joint. In one embodiment, the stem 310 of universal facet prosthesis 330 is fixed into the L5 vertebra 105 with poly (methylmethacrylate) bone cement, hydroxyapatite, a ground bone composition, or a combination thereof. In another embodiment, both the stem 310 and the cup member 315 are fixed to a vertebra with stainless steel wire to provide addition stability.
[0079] The new support provided by a universal facet prosthesis 330 helps correct degenerative spine diseases such as spondylolisthesis, spinal stenosis, or any spine disease. As demonstrated by comparing FIG. 1 showing a spondylolisthetic spine with slippage between the L4 vertebra 100 and the L5 vertebra 105 with FIG. 3 where the diseased superior half 305 of the facet joint has been replaced with a superior universal facet prosthesis 330 of the present invention, correcting spondylolisthesis at the L4-L5 joint and preventing further spondylolisthesis. Similarly, where correction of scoliosis and/or kypho-scoliosis is desired, the size and/or shape of the prosthesis may be chosen to re-orient the affected level(s) of the spine.
[0080] The superior universal facet prosthesis 330 described above may be used as a replacement for the superior half of one or more of facet joints at any facet joint at any level of the spine. In the preferred embodiment, the universal facet prosthesis 330 is used to replace the superior half of one or more facet joints in one or more facet joints. The superior facet prosthesis 330 is designed such that it has the appropriate cephalad and caudad directions as well as the appropriate medial/lateral angulation for the given level of the spine where the implant occurs.
[0081] In further embodiments, one or more surfaces of a universal facet prosthesis 330 may be covered with various coatings such as antimicrobial, antithrombotic, and osteoinductive agents, or a combination thereof. See, e.g., U.S. Pat. No. 5,866,113, which is incorporated herein by reference. These agents may further be carried in a biodegradable carrier material with which the pores of the stem and/or cup member of certain embodiments may be impregnated. See, e.g., U.S. Pat. No. 5,947,893, which is also incorporated herein by reference.
[0082] In still further embodiments of the present invention, a universal facet prosthesis may be attached to strengthened or fortified bone. Vertebrae may be strengthened prior to or during fixation of the prostheses using the methods, e.g., described in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening is particularly suggested for osteoporotic patients who wish to have facet replacement.
[0083] B. Surgical Method for Facet Replacement Using the Superior Universal Facet Prosthesis
[0084] A surgical procedure that embodies features of the invention replaces the superior half of a facet joint with the superior universal facet prosthesis 330 described above. The surgical procedure comprises exposing the spinous process, lamina, and facet joints at a desired level of the spine using any method common to those of skill in the medical arts. The prominent bone 306 b (see FIG. 5 ) may then be rongeured using any means common in the field. The superior facet 305 may also be trimmed, as depicted in FIG. 6 , to decompress the nerve root 203 . A reamer 400 , or any other instrument that is useful for grinding or scraping bone, may be used to ream the facet 305 b into the pedicle 304 b as depicted in FIG. 7 and FIG. 8 .
[0085] In a preferred embodiment (see FIG. 9 ), an opening 407 is made into the vertebral body 107 with a broach 405 . The universal facet prosthesis 330 b is installed into the opening 407 made by the broach 405 , as shown in FIG. 10 . The opening 407 may be partly filled with bone cement, hydroxyapatite, or any bone adhesive before installation of the universal facet prosthesis 330 b.
[0086] In an alternative embodiment, the stem 310 of the superior universal facet prosthesis 330 may be constructed in such a way that the superior universal facet prosthesis 330 can be directly screwed or tapped into the vertebral body 107 .
[0087] In another arrangement, the cup member 315 of the universal facet member 330 may additionally be fixed to the vertebral body 107 with bone cement, hydroxyapatite, or any other biocompatible adhesive. In yet another arrangement, a universal facet prosthesis without a stem 310 may be attached to the vertebral body with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away anchors to facilitate later removal of the prosthesis, or a combination thereof, or any other means known in the art.
[0088] In a further embodiment of the present invention, the universal facet prosthesis 330 may be fixed into strengthened or fortified bone. Vertebrae may be strengthened prior to or during fixation of the prosthesis using the methods described in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening procedure is particularly suggested for osteoporotic patients who wish to have facet replacement surgery.
[0000] III. Inferior Lamina/Facet Prosthesis
[0089] A. Structure
[0090] An inferior lamina/facet prosthesis 500 that embodies features of the invention is shown in FIG. 11 . The prosthesis 500 is designated “inferior” because it creates an artificial facet surface for the inferior half of a facet joint. The artificial surface articulates with the superior half of the facet joint. The prosthesis 330 allows for the replacement of injured, diseased and/or deteriorating components along the inferior halves of facet joints to provide improved support for the spinal column.
[0091] The prosthesis 330 may span the distance from a region on one side of a vertebra to a region of the other side of the vertebra. It can thus replace both inferior halves of a facet joint.
[0092] FIG. 14 depicts a superior view of a vertebral body depicting sagitally oriented arthritic facets with lateral stenosis, showing how the spinal process 631 presses forward onto the nerve roots 205 and 200 . The prosthesis 500 allows for replacement of diseased and deteriorating inferior regions of the vertebra and partial replacement of lamina (see FIG. 12 ), which may be pressing on the spinal nerves, to relieve pain. The prosthesis 500 creates artificial facet surfaces for the inferior half of facet joints in the spine, which provide improved support for the spinal column.
[0093] As FIG. 12 shows, a superior universal facet prosthesis 330 , as described above, may also be installed to replace the superior halves of the facet joints and, with the inferior lamina/facet prosthesis 500 replacing the inferior halves of the facet joints, forming a total facet replacement system that can result in entire artificial facet joints along a length of the spinal column. Alternatively, just the inferior half one or more facet joints, or just the superior half of one or more facet joints, may be replaced. The inferior and/or superior halves of facet joints may be replaced on one side of a given vertebra (unilateral), on the both sides of a given vertebra (bilateral), or a combination of each along a length of the spinal column.
[0094] The inferior lamina/facet prosthesis 500 may be constructed in various ways. As shown in FIG. 11 , the prosthesis 500 can comprise a base member 505 . The base member 505 may be made of any joint materials commonly used in the prosthetic arts, including, but not limited to, metals, ceramics, titanium, titanium alloys, tantalum, chrome cobalt, surgical steel, bony in-growth surfaces, artificial bone, uncemented surface metals or ceramics, or a combination thereof. The base member 505 may also be any appropriate shape to give appropriate support to the spine and to appropriately and sturdily attach to the inferior portions of a vertebral body. The base member 505 may be fixed or anchored directly to the inferior portion of a vertebral body with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away screws to facilitate any future removal of the prosthesis, or a combination thereof, or any other means known in the art.
[0095] In a preferred arrangement, as depicted in FIG. 11 , FIG. 12 , and FIG. 13 , the base member 505 of the inferior lamina/facet prosthesis 500 is attached to each pedicle 102 a and 102 b with bilateral pedicle screws 520 a and 520 b . The base member 505 of the inferior lamina/facet prosthesis 500 may further be attached to the spinous process 630 with a trans-spinous-process screw 515 to provide additional stability.
[0096] In another embodiment, the inferior lamina/facet prosthesis 500 may have a head member 510 for articulation with the cup member 315 of a superior universal facet prosthesis 330 or with a superior articular process of the adjoining vertebral body. The head member 510 may be made of various materials commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, tantalum, titanium, chrome cobalt, surgical steel, bony in-growth surfaces, ceramics, artificial bone, or a combination thereof. The head member 510 may further be any shape which facilitates attachment to the rest of the inferior lamina/facet prosthesis 500 and to smooth connection to, and movement in orientation to, a universal facet prosthesis 330 or a superior articular process of an adjoining vertebral body. In one embodiment, a head member 510 is attached to the base member 505 of the inferior facet/lamina prosthesis 500 with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, or any other means known in the art. The head member 510 may also be removably attached by frictional engagement (e.g., using a Morse taper).
[0097] In a preferred embodiment (see FIGS. 11 and 12 ), the inferior facet/lamina prosthesis 500 comprises two head members 510 a and 510 b formed in the shape of an articular head. The head members 510 a and 510 b preferably each have a Morse taper 512 at their upper surface to allow them to lock into the base member 505 of the inferior facet/lamina prosthesis 500 . Of course, either or both head members 510 a and 510 b could be formed integrally with the prosthesis 500 . In the preferred arrangement, a complete prosthetic facet joint 560 is provided (see FIG. 11 ), in which the head members 510 a and 510 b articulate with the cup member 315 of the superior universal facet prosthesis 330 .
[0098] In further embodiments, one or more surfaces of the inferior lamina/facet prosthesis 500 may be covered with various coatings such as antimicrobial, antithrombotic, and osteoinductive agents, or a combination thereof. See, e.g., U.S. Pat. No. 5,866,113, which is incorporated herein by reference. These agents may further be carried in a biodegradable carrier material with which the pores of the base member and/or any screws, bolts, or nails of certain embodiments may be impregnated. See, e.g., U.S. Pat. No. 5,947,893, which is incorporated herein by reference.
[0099] In other arrangements, an inferior lamina/facet prosthesis 500 may be attached to strengthened or fortified bone. Vertebrae may be strengthened prior to or during fixation of the prosthesis using the methods described, e.g., in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening is particularly suggested for osteoporotic patients who wish to have facet replacement.
[0100] B. Surgical Method for Partial Inferior Lamina/Facet Replacement Using the Inferior Lamina/Facet Prosthesis
[0101] A surgical procedure that embodies features of the invention replaces inferior lamina and articulated processes with the inferior lamina/facet prosthesis 500 as described above. The surgical procedure exposes the spinous process, lamina, and facet joints at a desired level of the spine using any method common to those of skill in the medical arts. As FIG. 15 shows, an inferior one eighth to one half of the spinous process 302 may be cut along the spinous process resection line 610 and removed, if the spinous process appears diseased or damaged. The cutting and removal of the spinous process may be performed using any means common in the field.
[0102] As shown in FIGS. 16 and 17 , the inferior half of the facet joint may also be cut at or near the inferior facet resection line 600 . In a preferred embodiment (see FIGS. 16 and 17 ), most of the lamina 615 is preserved, as is the facet joint capsule 625 , which may be opened and folded back. In a preferred embodiment, the facet joint capsule 625 may be cut perpendicular to its direction. The inferior half 621 of the facet joint 620 may then be retracted from the superior half 622 . Once the facet joint 620 is separated, the cut inferior bone 615 of the upper joint (i.e. the cut inferior portion of the L4 vertebra in the L4-L5 joint) may be removed. Alternatively, it may be possible to remove the cut inferior bone 615 while simultaneously separating the facet joint 620 .
[0103] In a preferred embodiment (see FIGS. 18 and 19 ), a superior universal facet prosthesis 330 is then installed as previously described. Alternatively, the superior universal facet prosthesis 330 may be installed before the inferior bone is removed or even cut.
[0104] An inferior lamina/facet prosthesis 500 as described above may be placed onto the facet joints and over the spinous process. The inferior lamina/facet prosthesis 500 may be fixed or anchored to the vertebral body with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away screws, or a combination thereof to facilitate any future removal of the prosthesis, or any other means known in the art. In the preferred embodiment (see FIG. 11 , FIG. 12 , and FIG. 13 ), the inferior lamina/facet prosthesis 500 is attached to each pedicle 102 a and 102 b of the inferior facets with bilateral pedicle screws 520 a and 520 b and is further attached to the spinous process 630 with a trans-spinous-process screw 515 to provide additional stability.
[0105] A head member 510 of an inferior lamina/facet prosthesis 500 may articulated into the cup member 315 of the superior universal facet prosthesis 330 , or into a inferior half of a facet joint if the inferior half has not been replaced, to create a complete prosthetic facet joint.
[0106] In an alternative embodiment, as depicted by FIG. 19 , the inferior facet resection line 610 may be a V-type cut. If a V-type cut is used, an appropriately shaped inferior lamina/facet prosthesis 550 should be used, such as depicted in FIG. 20 . The inferior facet resection line may alternatively be cut in other ways, which are apparent to one of skill in the art of orthopedic surgery and will require inferior lamina/facet prostheses of varying shapes to appropriately fit the cut vertebra.
[0107] In a further embodiment of the present invention, a universal facet prosthesis and/or an inferior lamina/facet prosthesis may be fixed into strengthened or fortified bone. Vertebrae may be strengthened prior to or during fixation of the prosthesis using the methods described, e.g., in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening procedure is particularly suggested for osteoporotic patients who wish to have facet replacement surgery.
[0000] IV. Hemi-Lamina/Facet Prosthesis
[0108] A. Structure
[0109] A hemi-lamina/facet prosthesis 700 that embodies features of the invention (see FIG. 21 ) may be used to replace parts of a lamina and inferior processes, some or all which may have been removed in a primary procedural bone resection, (i.e. with or without wide decompressive laminectomy). The hemi-lamina/facet prosthesis 700 may be designed similarly, or even identically, to the inferior lamina/facet prosthesis 500 described above, depending on how much of the bone is removed.
[0110] The hemi-lamina/facet prosthesis 700 may be constructed in various ways. In one embodiment, hemi-lamina/facet prosthesis 700 may, e.g., comprise a base member 705 . The base member 705 may be made of any joint materials commonly used in the prosthetic arts, including, but not limited to, metals, ceramics, titanium, titanium alloys, tantalum, chrome cobalt, surgical steel, bony in-growth surfaces, artificial bone, uncemented surface metals or ceramics, or a combination thereof. The base member 705 may be any shape which gives appropriate support to the spine and can be appropriately attached to the bone of the remaining lamina. The base member 705 may be fixed or anchored directly to the inferior portion of a vertebral body with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away screws to facilitate any future removal of the prosthesis, a combination thereof, or any other means known in the art.
[0111] In a preferred embodiment (see FIG. 21 ) of a prosthesis for hemiarthroplasty (depicted as cut line 800 and further described below) without decompressive laminectomy, the base member 705 of the hemi-lamina/facet prosthesis 700 is attached to superior pedicle 102 b with a pedicle screw 720 . In another preferred embodiment, the base member 705 of the hemi-lamina/facet prosthesis 700 may further be attached to the spinous process 630 with a trans-spinous-process screw 715 to provide additional stability.
[0112] In a preferred embodiment (see FIGS. 24 and 25 ) of a prosthesis for hemiarthroplasty with wide decompressive laminectomy, the hemi-lamina/facet prosthesis 700 comprises at least one base member 705 . The base member 705 may further comprise a pedicle attachment hole 725 through which a pedicle screw 720 , or a nail, anchor, break-away anchor, bolt, or any other fastening means, may be installed to help secure the hemi-lamina/facet prosthesis 700 to the inferior pedicle. In the preferred embodiment, the base member 705 may also have at least one lamina attachment hole, with two lamina attachment holes 741 and 742 pictured in FIG. 22 , to further secure the hemi-lamina/facet prosthesis 700 to the remaining laminal bone with screws, nails, anchors, break-away anchors, bolts, or any other fastening means. Parts of the hemi-lamina/facet prosthesis 700 which overlap bone may be additionally fixed with bone cement, or any biocompatible adhesive.
[0113] A hemi-lamina/facet prosthesis 700 may further comprise a connection plate, similar to the connection plate 750 depicted in FIG. 24 , to connect two base members, i.e. 705 a and 705 b , together. The connection plate 750 may be fixed to each base member 705 a and 705 b with a biocompatible adhesive, screws, nails, bolts, compressive force, a combination thereof, or any other means common to those of skill in the art. Alternatively, a hemi-lamina/facet prosthesis 700 may further comprise at least one stabilization bar, similar to the stabilization bars 761 and 762 depicted in FIG. 25 . A stabilization bar or bars may be fixed to each base member 705 a and 705 b with a biocompatible adhesive, screws, nails, bolts, compressive force, a combination thereof, or any other means common to those of skill in the art. A hemi-lamina/facet prosthesis 700 may have any type of bridging or stabilizing members, or no bridging members at all, and may be comprised of any number of base members to provide appropriate stability to the spine. The bridging members may be made of any joint materials commonly used in the prosthetic arts, including, but not limited to, metals, ceramics, titanium, titanium alloys, tantalum, chrome cobalt, surgical steel, bony in-growth surfaces, artificial bone, uncemented surface metals or ceramics, or a combination thereof.
[0114] In another embodiment, a hemi-lamina/facet prosthesis 700 may have a head member 710 for articulation with the cup member 315 of a superior universal facet prosthesis 330 or with the superior articular process of an adjoining superior pedicle. The head member 710 may be made of various materials commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, chrome cobalt, surgical steel, bony in-growth sintering, sintered glass, artificial bone, or a combination thereof. The head member 710 may further be any shape which allows it to attach to the rest of the hemi-lamina/facet prosthesis 700 and to smoothly connect to, and move in orientation to, the universal facet prosthesis 330 or superior articular facet of the adjoining superior pedicle. In one embodiment, the head member 710 is attached to the rest of the hemi-lamina/facet prosthesis with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, a combination thereof, or any other means known in the art. The head member 710 may be removably attached, using, e.g., a Morse taper.
[0115] In a preferred embodiment, hemi-lamina/facet prosthesis 700 comprises a head member 710 made in the shape of an articular head. The head member 710 preferably has a Morse Taper at its upper surface to allow it to lock into hemi-lamina/facet prosthesis 700 .
[0116] In further embodiments, one or more surfaces of a hemi-lamina/facet prosthesis 700 may be covered with various coatings such as antimicrobial, antithrombotic, and osteoinductive agents, or a combination thereof. See, e.g., U.S. Pat. No. 5,866,113, which is incorporated herein by reference. These agents may further be carried in a biodegradable carrier material with which the pores of the base member and/or any screws, bolts, or nails of certain embodiments may be impregnated. See, e.g., U.S. Pat. No. 5,947,893, which is incorporated herein by reference.
[0117] In still further embodiments of the present invention, a hemi-lamina/facet prosthesis 700 may be attached to strengthened or fortified bone. Vertebrae may be strengthened prior to or during fixation of the prosthesis using the methods described, e.g., in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening is particularly suggested for osteoporotic patients who wish to have facet replacement.
[0118] B. Hemiarthroplasty With or Without Wide Decompressive Laminectomy Using the Hemi-Lamina/Facet Prosthesis
[0119] A surgical procedure that embodies features of the invention removes at least part of a lamina and at least one superior portion of a facet joint and replacing it with a hemi-lamina/facet prosthesis 700 as described above. The general surgical procedure is generally similar to the inferior lamina/facet replacement previously described, with the main difference being the types of cuts made into the laminal bone, and that two separate prostheses are used to replace the superior portions of two facet joints (left and right) of a given vertebra.
[0120] One embodiment of the surgical procedure comprises exposing the spinous process, lamina, and facet joints at a desired level of the spine using any method common to those of skill in the medical arts. The inferior facet joint and part of the lamina may be cut with a hemiarthroplasty resection line 800 as depicted in FIG. 26 for a hemiarthroplasty. The lamina may additionally be cut for a wide decompressive laminectomy along the decompression resection line 810 as depicted in FIG. 26 . The inferior facet joint may be cut on one side or both sides of the lamina. Likewise, the lamina may be cut along a decompression resection line on one side or both sides.
[0121] In a preferred embodiment of a hemiarthroplasty without a wide decompressive laminectomy, leaving the cut inferior facet bone 300 in place, the facet joint capsule 625 may be opened and folded back. In the preferred embodiment, the facet joint capsule 625 may be cut perpendicular to its direction. The inferior half 621 of the facet joint 620 may then be retracted from the superior half 622 . Once the facet joint 620 is separated, the cut inferior facet bone 825 may be removed. Alternatively, it may be possible to remove the cut inferior facet bone 825 while simultaneously separating the facet joint 620 .
[0122] In a preferred embodiment of a hemiarthroplasty with a wide decompressive laminectomy, a superior universal facet prosthesis 330 is then installed as previously described, and depicted in FIG. 18 .
[0123] A base member 705 of hemi-lamina/facet prosthesis 700 as described in any of the embodiments above may be placed onto at least one facet joint and at least one pedicle as depicted in FIG. 23 , and over the spinous process if it has not been removed for hemiarthroplasty without decompressive laminectomy as depicted in FIG. 21 . The hemi-lamina/facet prosthesis 700 may be fixed or anchored to the vertebral body with poly(methylmethacrylate) bone cement, hydroxyapatite, screws, nails, bolts, anchors, break-away screws to facilitate any possible future removal of the prosthesis, a combination thereof, or any other means known in the art. In the preferred embodiment, as depicted in FIG. 21 , FIG. 24 , and FIG. 25 , the hemi-lamina/facet prosthesis 500 is attached to each pedicle with bilateral pedicle screws 720 .
[0124] A hemi-lamina/facet prosthesis 700 that may be used in hemiathroplasty without wide decompressive laminectomy, depicted in FIG. 21 , may further be attached to the spinous process 630 with a trans-spinous-process screw 715 to provide additional stability. A hemi-lamina prosthesis 700 that may be used in hemiathroplasty with wide decompressive laminectomy, as depicted in FIGS. 23, 24 , and 25 , may further be attached to remaining laminal bone with screws, bolts, nails, anchors, or breakaway anchors through at least one lamina attachment hole 741 to provide additional stability.
[0125] In embodiments where a hemi-lamina/facet prosthesis 700 with more than one base member 705 is installed, a connection plate, depicted as connection plate 750 in FIG. 24 , at least one stabilization bar, depicted as stabilization bars 761 and 762 in FIG. 25 , or any other connecting or stabilizing means known in the art, may be installed with the base members to provide additional stability to the spine:
[0126] At least one head member, depicted as head member 710 in FIGS. 21, 23 , 24 , and 25 , of a hemi-lamina/facet prosthesis 700 may be articulated into a cup member of a superior universal facet prosthesis 330 to create a prosthetic facet joint capsule.
[0127] The embodiments may be used to replace one or more facet joints for the entire length of the spine from S1 to T11, on one side of a given vertebra, or both sides of a given vertebra, or a combination thereof along a length of the spine. If only one facet joint at a given level is to be replaced, the unilateral arthroplasty prosthesis for the inferior half of the joint may be fixed to the superior ipso-lateral pedicle and include a box fitted over the spinous process, combined with screw fixation. The spinous process box is similar to the spinous process box in the bilateral total facet arthroplasty embodiment previously discussed.
[0128] In a further embodiment of the present invention, a universal facet prosthesis 330 and/or a hemi-lamina/facet prosthesis 700 may be fixed into strengthened or fortified bone. The vertebrae may be strengthened prior to or during fixation of the prosthesis using the methods described, e.g., in U.S. Pat. No. 5,827,289, which is incorporated herein by reference. This type of bone strengthening procedure is particularly suggested for osteoporotic patients who wish to have facet replacement surgery.
[0000] V. Other Facet Prostheses
[0129] A. Single Side
[0130] FIGS. 29 and 30 show an inferior prosthesis 26 that embodies features of the invention. The prosthesis 26 is designated “inferior” because it creates an artificial facet surface in the inferior half of a facet joint. The artificial surface articulates with the superior half of the facet joint. The prosthesis 26 is particularly well suited to single-sided procedures and/or for procedures involving vertebral bodies which are not symmetrical.
[0131] When the processes on one side of a vertebral body are differently spaced from those on the other side of the same body, the prostheses on each side would desirably be of differing sizes as well. Moreover, it is often difficult and/or impossible for a surgeon to determine the precise size and/or shape necessary for a prosthesis until the surgical site has actually been prepared for receiving the prosthesis. In such a case, the surgeon typically needs a family of prostheses possessing differing sizes and/or shapes immediately available during the surgery. The surgeon cannot wait for a custom-fitted device to be created during the surgery, so a number of prostheses of varying sizes and/or shapes must be available for each procedure.
[0132] The prosthesis 26 can be conveniently formed in different sizes and shapes, to offer an array of prostheses 26 from which the surgeon can pick and choose as surgery proceeds. This allows a surgeon to create a “custom” implant during the surgical procedure.
[0133] In the illustrated embodiment (see FIGS. 29 and 30 ), the prosthesis 26 comprises a body 28 sized and shaped to span the distance between a pedicle 14 and an inferior articular process 24 on the same side of a vertebral body (see FIG. 31 ). The body 28 may be formed of a material commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, chrome cobalt, surgical steel, bony in-growth sintering, sintered glass, artificial bone, or a combination thereof.
[0134] The upper section of the body 28 desirably includes an opening 32 . The opening 32 accommodates a pedicle screw 34 (see FIG. 41 ), which secures the upper end of the body 28 into the pedicle 14 of the vertebral body. The opening 32 could be elongated, to allow for varying orientations and/or sizes of the pedicle screw 34 . The remainder of the link body 28 can be secured to the exterior of the vertebra using, e.g., biocompatible adhesive.
[0135] The lower section of the body 28 is oriented to serve as the superior half of a facet joint. The lower section of the body 28 desirably incorporates a head 30 . The head 30 can be permanently affixed to the body 28 , using, e.g., adhesive. Alternatively, the head can be frictionally secured, e.g., using a Morse taper, for removal and replacement (as FIG. 41 shows). Like the body 28 , the head 30 can be formed of a material commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, chrome cobalt, surgical steel, bony in-growth sintering, sintered glass, artificial bone, or a combination thereof. The head 30 possesses a curvilinear shape that desirably curves along a gradual arc (as FIG. 42 shows), or can present a “button” shape.
[0136] If desired, the lower section of the joint link body 28 could be angled, to more naturally mimic the orientation of a non-diseased facet joint. In one alternative embodiment, the lower section of the joint link body 28 could rotate relative to the upper section, and could be rotationally secured in a desired position by a surgeon using a locking screw or other locking means known in the art. Such an embodiment would allow the surgeon to alter the orientation of the lower section to fit the particular needs of a patient during the actual surgical procedure.
[0137] In use (see FIG. 31 ), the head 30 articulates with the superior half of the facet joint. The superior facet 22 can comprise the natural superior articular process itself (as FIG. 31 shows), or it can comprise a superior prosthetic facet created, e.g., by the previously described universal facet prosthesis 330 (as FIG. 42 shows). The surface member 320 of the universal facet prosthesis 330 can comprise a metal material made of, e.g., titanium, cobalt, chrome, etc., or a plastic material such as, e.g., polyethylene, or a ceramic material. Thus the surgeon can select the same or different materials to form the joint interface between the head 30 and facet prosthesis 330 .
[0138] FIGS. 34 and 35 show another embodiment of an inferior universal prosthesis 36 that embodies features of the invention. The prosthesis 36 , like the prosthesis 26 , is designated “inferior” because it creates an artificial facet surface in the inferior half of the facet joint. The artificial surface articulates with the superior half of the facet joint. Like the prosthesis 26 , the prosthesis 36 is particularly well suited to single-sided procedures and/or for procedures involving vertebral bodies which are not symmetrical.
[0139] The prosthesis 36 comprises a body 38 sized and shaped to span the distance between a pedicle 14 and an inferior articular process 24 (see FIG. 35 ). The body 38 may be formed of the same types of material as the link body 28 . Like the link body 28 , the upper section of the joint link body 38 desirably includes an opening 42 , to accommodate a pedicle screw 34 (see FIG. 35 ), which secures the upper end of the body 38 into the pedicle 14 of the vertebral body, in similar fashion as generally shown in FIG. 41 . As before described with reference to the link 26 , the opening 42 in the link body 38 could be elongated, to allow for varying orientations and/or sizes of the pedicle screw 34 . The remainder of the link body 28 can be secured to the exterior of the vertebra using, e.g., biocompatible adhesive.
[0140] Unlike the link body 28 , the link body 38 includes an intermediate opening 44 . In use (see FIG. 35 ), the spinous process 18 (if present) can extend through the opening 44 , to stabilize the link body 38 on the vertebral body. Desirably, a trans-spinous-process screw 45 can be used to provide additional stability.
[0141] The lower section of the joint link body 38 is oriented to serve as the inferior half of a facet joint. The lower section of the joint link body 38 desirably incorporates a head 40 , which can be constructed in the same fashion as the head 30 of the link 26 . Like the head 30 , the facet head 40 can be permanently affixed to the body 38 or can be secured in with a frictional fit (e.g., using a Morse taper) for removal and replacement. Like the head 30 , the head 40 can be formed of a material commonly used in the prosthetic arts.
[0142] In use (see FIG. 35 ), the head 40 articulates with the superior half of the facet joint with the next adjacent vertebra level. As before explained for the link 26 , the superior facet 22 can comprise the natural superior articular facet 22 itself, or it can comprise a prosthetic facet created, e.g., by the previously described universal facet prosthesis 330 .
[0143] FIG. 32 shows a superior prosthetic link 26 ′ that also embodies features of the invention. The prosthetic link 26 ′ is designated “superior” because it creates an artificial facet surface in the superior half of a facet joint. The artificial surface articulates with the inferior half of the facet joint. The superior prosthesis link 26 ′, like the prosthesis 26 , is particularly well suited to single-sided procedures and/or for procedures involving vertebral bodies which are not symmetrical.
[0144] A stem 37 extends out from the upper end of the link 26 ′. The stem 37 is inserted (by screwing or tapping) into the pedicle, to thereby secure the link 26 ′ to the vertebral body.
[0145] As FIG. 32 shows, the upper end of the link 261 is shaped to form a cup 36 , which articulates with the inferior half of the facet joint.
[0146] The inferior half of the facet joint can comprise the natural inferior articular process 24 itself (as FIG. 32 shows), or it can comprise the head 30 of an inferior prosthesis 26 or link 26 ′ attached to the next adjacent upper vertebra level (as FIG. 33 shows).
[0147] The lower end of the link 26 ′ can also carry a head 30 for articulation with the superior half of a facet joint with the next adjacent lower vertebra. The superior half of the facet joint can comprise the natural superior articular process 22 itself, or it can comprise the cup of a link 26 ′ attached to the next adjacent lower vertebra level.
[0148] It can thus be appreciated that the link 26 ′ is well suited for use in procedures requiring replacement of multiple levels of facet joints, and can be interlinked in superior and inferior pairs, like a structure formed out of interlinking tinker-toy pieces. The link 26 ′ also allow subsequent surgeries to build upon already replaced levels, rather than requiring the removal and replacement of an existing implant to accommodate replacement of failing facet joints in an adjacent level. It should be appreciated that the upper end of the prosthesis 36 can also be shaped to form a cup to articulate with the superior half of the facet joint with the next adjacent upper vertebra level.
[0149] The prosthesis 26 , 36 , or link 26 ′ are well suited for use in a single side of the vertebral body, such as where the facet joints need only be replaced on a single side of the vertebral body. The prosthesis 26 , 36 , or link 26 ′ are also well suited for use in a dual-sided procedure where the vertebral body is either symmetrical or non-symmetrical. In this arrangement, other prostheses 26 , 36 , or links 26 ′ can be secured on the opposite side of the vertebral body, allowing both sides of the vertebral body to be treated. Because the surgeon can pick prostheses 26 , 36 , and links 26 ′ of varying sizes, depending upon the size of the vertebral site, and can individually position each prosthesis 26 or link 26 ′ relative to the vertebral body, the surgeon can tailor the linked implant system to the individual's needs.
[0150] B. Multiple Level, Sequential Link Assemblies
[0151] FIG. 36 shows a universal prosthetic joint link assembly 56 that embodies features of the invention. The joint link assembly 56 is particularly well suited to double-sided procedures and for sequential, multiple level procedures.
[0152] In the illustrated embodiment (see FIG. 36 ), the joint link assembly 56 comprises two criss-crossing link bodies 58 and 60 . Each body 58 and 60 (shown mutually separated in FIGS. 37 and 38 , respectively) may be formed of a material commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, chrome cobalt, surgical steel, bony in-growth sintering, sintered glass, artificial bone, or a combination thereof.
[0153] As FIG. 36 shows, the link bodies 58 and 60 are desirably locked together for use at an intermediate key-way 62 , to form the x-shaped, criss-crossing assembly 56 . The key-way 62 is formed by a shaped opening 68 in one body 60 (see FIG. 37 ) and a mating shaped key 70 in the other body 58 (see FIG. 38 ). The key 70 nests within the opening 60 (as FIG. 36 shows), to frictionally hold the bodies 58 and 60 together and resist relative rotation between the bodies 58 and 60 .
[0154] Of course, the shape of the opening 68 and key 70 can vary. In FIGS. 36, 37 , and 38 , the opening 68 and key 70 are generally square or rectilinear in shape. In FIG. 39 , an alternative link body 58 is shown, which possesses a key 70 ′ that is generally octagonal in shape, sized to nest within a corresponding octagonal opening in the other link (not shown). In this arrangement, the two link bodies 58 and 60 can be mutually assembled in different arcuately spaced orientations, allowing for variations in facet joint size and positioning. If desired, the key-way 62 could alternately be formed in a tooth and gear arrangement, which would desirably allow a multiplicity of potential arcuately spaced orientations for the two link bodies 58 and 60 forming the assembly 56 .
[0155] The key 70 desirable peripherally defines an opening 72 (see FIG. 38 ), through which the spinous process 18 can (if present) project during use. This is generally shown in phantom lines by FIG. 41 .
[0156] Alternatively, the link bodies 58 and 60 could be formed in a criss-crossing shape as a single, unitary body.
[0157] The upper section of each link body 58 and 60 desirably includes a cup 64 . The cups 64 form the left and right superior halves of a facet joint and, in use, articulate with the left and right inferior halves of the facet joint.
[0158] A stem 65 extends out from the upper end of each link body 58 and 60 . The stem 67 is inserted (by screwing or tapping) into the pedicle, to thereby secure the link bodies 58 and 60 to the vertebral body. In use, the stems 67 secure the upper end of the bodies 58 and 60 into an opposite pedicle 14 of a vertebral body.
[0159] As FIG. 40 best shows, the bodies 58 and 60 are each sized, shaped and mutually oriented to span the distance between a pedicle 14 on one side of the vertebral body and the region of the inferior articular process on the opposite side of the vertebral body. The remainder of the link bodies 58 and 60 can be secured to the exterior of the vertebra using, e.g., biocompatible adhesive. A trans-spinous-process screw 63 can also be used to provide additional stability.
[0160] The lower section of each link body 58 and 60 is oriented to serve as the inferior half of a facet joint. As FIG. 40 shows, the link body 58 , secured to the right pedicle, is positioned to serve as the inferior half of the facet joint on the left side of the vertebra. The link body 60 , secured to the left pedicle, is positioned to serve as the inferior half of the facet joint on the right side of the vertebra. For this purpose, the lower section of each link body 58 and 60 desirably incorporates a head 66 . As before explained, the head 66 can be permanently affixed to each body 58 and 60 or it can be secured in a frictional way using, e.g., a Morse taper for removal and replacement. Like the bodies 58 and 60 , the head 66 can be formed of a material commonly used in the prosthetic arts including, but not limited to, polyethylene, rubber, titanium, chrome cobalt, surgical steel, bony in-growth sintering, sintered glass, artificial bone, or a combination thereof.
[0161] In use, the heads 66 articulate with the superior halves of the left and right facet joints with the next adjacent vertebra level. As earlier described with reference to the single link structures, the superior halves of the facet joints can comprise the natural superior articular process 22 itself, or it can comprise a prosthetic facet created, e.g., by the cups 64 of another link assembly 56 secured to the next adjacent lower vertebra.
[0162] The interlocking of the crisscrossing link bodies 58 and 56 increases the strength of the overall link assembly 56 . The link assembly 56 distributes forces to both of the pedicles (and the spinous process, if desired), rather than relying upon fixation to a single pedicle.
[0163] Like the link 26 ′, the link assembly 56 is well suited for implantation in procedures requiring replacement of multiple levels of facet joints, and can be interlinked in superior and inferior pairs, like a structure formed out of interlinking tinker-toy pieces. Like the link 26 ′, the link assembly 56 also allows subsequent surgeries to build upon already replaced levels, rather than requiring the removal and replacement of an existing implant to accommodate replacement of failing facet joints in an adjacent level.
[0164] The size and shape of any prosthesis disclosed herein are desirably selected by the physician, taking into account the morphology and geometry of the site to be treated. The shape of the joint, the bones and soft tissues involved, and the local structures that could be harmed if move inappropriately, are generally understood by medical professionals using textbooks of human anatomy along with their knowledge of the site and its disease and/or injury. The physician is also desirably able to select the desired shape and size of the prosthesis and its placement in and/or around the joint based upon prior analysis of the morphology of the targeted joint using, for example, plain film x-ray, fluoroscopic x-ray, or MRI or CT scanning. The shape, size and placement are desirably selected to optimize the strength and ultimate bonding of the prosthesis to the surrounding bone and/or tissue of the joint.
[0165] Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. All documents referenced herein are specifically and entirely incorporated by reference. The specification and examples should be considered exemplary only with the true scope and spirit of the invention indicated by the following claims. As will be easily understood by those of ordinary skill in the art, variations and modifications of each of the disclosed embodiments can be easily made within the scope of this invention as defined by the following claims.
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Devices and surgical methods treat various types of adult spinal pathologies, such as degenerative spondylolisthesis, spinal stenosis, degenerative lumbar scoliosis, and kypho-scoliosis. Various types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments are used to perform the surgical procedures.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation in part of U.S. patent application Ser. No. 11/103,959, “MRI BIOPSY DEVICE LOCALIZATION FIXTURE” to Hughes et al., filed on 12 Apr. 2005, the disclosure of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates, in general, to a method of imaging assisted tissue sampling and, more particularly, to an improved method for positioning a biopsy probe with respect to a magnetic resonance imaging (MRI) breast coil for acquiring subcutaneous biopsies and for removing lesions.
BACKGROUND OF THE INVENTION
[0003] Core biopsy devices have been combined with imaging technology to better target a lesion in breast tissue. One such commercially available product is marketed under the trademark name MAMMOTOME™, by Ethicon Endo-Surgery, Inc. An embodiment of such a device is described in U.S. Pat. No. 5,526,822 issued to Burbank, et al., on Jun. 18, 1996, and is hereby incorporated herein by reference. Its handle receives mechanical and electrical power as well as vacuum assist from a remotely positioned control module that is spaced away from the high magnetic field of a Magnetic Resonance Imaging (MRI) machine
[0004] As seen from that reference, the instrument is a type of image-guided, percutaneous coring, breast biopsy instrument. It is vacuum-assisted, and some of the steps for retrieving the tissue samples have been automated. The physician uses this device to capture “actively” (using the vacuum) the tissue prior to severing it from the body. This allows the sampling of tissues of varying hardness. In addition, a side opening aperture is used, avoiding having to thrust into a lesion, which may tend to push the mass away, cause a track metastasis, or cause a hematoma that, with residual contrast agent circulating therein, may mimic enhancement in a suspicious lesion. The side aperture may be rotated about a longitudinal axis of the probe, thereby allowing multiple tissue samples without having to otherwise reposition the probe. These features allow for substantial sampling of large lesions and complete removal of small ones.
[0005] Vacuum assisted core biopsy devices have been adapted to be safe and compatible with various imaging modalities, including Magnetic Resonance Imaging (MRI). In particular, portions of a biopsy system placed near the magnet core of an MRI machine need to be nonresponsive to the strong magnetic field to prevent becoming drawn toward the magnet core or to malfunction. Further, the MRI machine depends upon sensing extremely weak radio frequency (RF) signals emanated by tissue after being excited by a strong change in the magnetic field. Components placed in the RF shielded MRI suite need to avoid producing electromagnetic interference (EMI) and need to avoid having materials that would distort RF signals sufficient to create artifacts in the MRI scan data.
[0006] A successful approach has been to segregate motive power generation, graphical user interface, vacuum assist, and closed loop control in a control module that has typically been placed about 6 feet away from the magnet core to mitigate detrimental interaction with its strong magnetic field and/or sensitive radio frequency (RF) signal detection antennas. An intuitive graphical user interface (GUI) provides a range of preprogrammed functionality incorporated into a control module to efficiently use time in an MRI suite to take tissue samples.
[0007] As an example, in U.S. Pat. No. 6,752,768, the disclosure of which is hereby incorporated by reference in its entirety, a control button may be depressed to change a mode of operation of a core biopsy device with this mode displayed remotely on a display.
[0008] While a full function GUI has numerous clinical benefits, the clinician may find the control module inconveniently remote during hands-on portions of the procedure. In addition, some MRI machines have such increased sensitivity and/or increased magnet field strength that it is desirable to increase the distance of the control monitor (e.g., 30 feet) from the MRI machine. Further, even if the control monitor is sufficiently close, some clinicians prefer a simplified user interface to simplify training familiarity.
[0009] Consequently, a significant need exists for a biopsy system compatible for use in an MRI suite with biopsy controls with enhanced convenience and intuitiveness.
BRIEF SUMMARY OF THE INVENTION
[0010] The invention overcomes the above-noted and other deficiencies of the prior art by providing a handpiece of a magnetic resonance imaging (MRI) compatible core biopsy system that includes a graphical user interface that facilitates user control even with vacuum, power generation, and control processing components remotely positioned away from the MRI magnet and sensitive radio frequency (RF) receiving components. Thereby, a clinician may have the full functionality of vacuum assisted core biopsy systems yet not be inconvenienced by the distance from a remotely positioned control module.
[0011] These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
[0013] FIG. 1 is a perspective disassembled view of a Magnetic Resonance Imaging (MRI) biopsy system including a handpiece (“biopsy device”) having intuitive graphical controls consistent with aspects of the invention.
[0014] FIG. 2 is an isometric view of a lateral fence and pedestal of a localization fixture of the MRI biopsy system of FIG. 1 .
[0015] FIG. 3 is an isometric view of a guidance assembly mounted on a right primary targeting rail of FIG. 2 .
[0016] FIG. 4 is an exploded isometric view of the guidance assembly of FIG. 3 and the sleeve trocar and introducer obturator of FIG. 1 .
[0017] FIG. 5 is an isometric view of the introducer obturator inserted into the sleeve trocar of FIGS. 1 and 4 .
[0018] FIG. 6 is an aft right isometric view of the MRI biopsy device of FIG. 1 with a disposable probe assembly and keypad control disengaged from a reusable holster portion.
[0019] FIG. 7 is a fore left isometric view of the MRI biopsy device of FIG. 1 with the disposable probe assembly and keypad control disengaged from the reusable holster portion.
[0020] FIG. 8 is a fore left exploded isometric view of the reusable holster portion of FIG. 7 .
[0021] FIG. 9 is a top view of the disposable probe assembly of FIG. 7 with an upper cover removed to expose interior components of a carriage cavity.
[0022] FIG. 10 is a fore left exploded isometric view of the disposable probe assembly of FIG. 7 .
[0023] FIG. 11 is an aft left isometric view of the localization fixture and guidance assembly installed into a breast coil of FIG. 1 .
[0024] FIG. 12 is an aft isometric view of the MRI biopsy device of FIG. 7 into the guidance assembly of FIG. 11 .
[0025] FIG. 13 is a top detail view of a display portion of the MRI biopsy device of FIG. 7 .
[0026] FIG. 14 is an aft right isometric view of the MRI biopsy device, localization fixture and breast coil of FIG. 12 with insertion of a marker deploying instrument through a probe of the disposable probe assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0027] An MRI biopsy device advantageously includes is partially disposable for sterility purposes with a reusable portion for economy. Inconvenience of mechanical, electrical, and pneumatical coupling to a remotely placed control portion, necessitated by a strong magnetic field and sensitive RF receiving components of an MRI machine, is mitigated. First, proximal detachable intuitive controls and displays on the MRI biopsy device give interactive control even after insertion into localizing and guiding structures. Second, binding of mechanical coupling to the MRI biopsy device is sensed prior to equipment damage or malfunction. Third, mechanical coupling is moved closer to engagement points between the MRI biopsy device and guiding structures to reduce torque loads, especially those transferred through its distal probe. Fourth, a single mechanical drive cable drives a fixed ratio transmission that translates and rotates a cutter of the distal probe to realize an effective fixed ratio translation/rotation sampling cut without the encumbrance of two mechanical drive cables.
[0028] Turning to the Drawings, wherein like numerals denote like components throughout the several views, in FIGS. 1-3 , a Magnetic Resonance Imaging (MRI) compatible biopsy system 10 has a control module 12 that typically is placed outside of a shielded room containing an MRI machine (not shown) or at least spaced away to mitigate detrimental interaction with its strong magnetic field and/or sensitive radio frequency (RF) signal detection antennas. As described in U.S. Pat. No. 6,752,768, which is hereby incorporated by reference in its entirety, a range of preprogrammed functionality is incorporated into the control module 12 to assist in taking these tissue samples. The control module 12 controls and powers an MRI biopsy device (“handpiece”) 14 that is positioned and guided by a localization fixture 16 attached to a breast coil 18 that is placed upon a gantry (not shown) of the MRI machine.
[0029] A cable management spool 20 is placed upon a cable management attachment saddle 22 that projects from a side of the control module 12 . Wound upon the cable management spool 20 is a paired electrical cable 24 and mechanical cable 26 which are bundled into sheathed cable 27 for communicating control signals and cutter rotation/advancement motions respectively. In particular, electrical and mechanical cables 24 , 26 each have one end connected to respective electrical and mechanical ports 28 , 30 in the control module 12 and another end connected to a reusable holster portion 32 of the MRI biopsy device 14 . An MRI docking cup 34 , which may hold the holster portion 32 when not in use, is hooked to the control module 12 by a docking station mounting bracket 36 .
[0030] An interface lock box 38 mounted to a wall provides a tether 40 to a lockout port 42 on the control module 12 . The tether 40 is advantageously uniquely terminated and of short length to preclude inadvertent positioning of the control module 12 too close to the MRI machine. An in-line enclosure 44 may advantageously register the tether 40 , electrical cable 24 and mechanical cable 26 to their respective ports 42 , 28 , 30 on the control module 12 .
[0031] Vacuum assist is provided by a first vacuum line 46 that connects between the control module 12 and an outlet port 48 of a vacuum canister 50 that catches liquid and solid debris. A tubing kit 52 completes the pneumatic communication between the control module 12 and the MRI biopsy device 14 . In particular, a second vacuum line 54 is connected to an inlet port 56 of the vacuum canister 50 . The second vacuum line 54 divides into two vacuum lines 58 , 60 that are attached to the MRI biopsy device 14 . With the MRI biopsy device 14 installed in the holster portion 32 , the control module 12 performs a functional check. Saline is manually injected into biopsy device 14 to serve as a lubricant and to assist in achieving a vacuum seal. The control module 12 actuates a cutter mechanism (not shown) in the MRI biopsy device 14 , monitoring full travel. Binding in the mechanical cable 26 or within the biopsy device 14 is monitored with reference to motor force exerted to turn the mechanical cable 26 and/or an amount of twist in the mechanical cable 26 sensed in comparing rotary speed or position at each end of the mechanical cable 26 .
[0032] Just proximal to a display area 61 on the reusable holster portion 32 , a remote keypad 62 , which is detachable from the reusable holster portion 32 , communicates via the electrical cable 24 to the control module 12 to enhance clinician control of the MRI biopsy device 14 , especially when controls that would otherwise be on the MRI biopsy device 14 itself are not readily accessible after insertion into the localization fixture 16 and/or placement of the control module 12 is inconveniently remote (e.g., 30 feet away). An aft end thumbwheel 63 on the reusable holster portion 32 is also readily accessible after insertion to rotate the side from which a tissue sample is to be taken.
[0033] Left and right parallel upper guides 64 , 66 of a localization framework 68 are laterally adjustably received respectively within left and right parallel upper tracks 70 , 72 attached to an under side 74 and to each side of a selected breast aperture 76 formed in a patient support platform 78 of the breast coil 18 . A base 80 of the breast coil 18 is connected by centerline pillars 82 that are attached to the patient support platform 78 between the breast apertures 76 . Also, a pair of outer vertical support pillars 84 , 86 on each side spaced about a respective breast aperture 76 respectively define a lateral recess 88 within which the localization fixture 16 resides.
[0034] In FIGS. 1-2 , a selected breast is compressed along an inner (medial) side by a medial plate 90 downwardly received into a medial three-sided frame 92 of the localization framework 68 . The breast is compressed from an outside (lateral) side of the breast by a lateral fence 94 downwardly received into a lateral three-sided frame 96 of the localization framework 68 , defining an X-Y plane. The X-axis is vertical (sagittal) with respect to a standing patient and corresponds to a left to right axis as viewed by a clinician facing the externally exposed portion of the localization fixture 16 .
[0035] Perpendicular to this X-Y plane extending toward the medial side of the breast is the Z-axis, which typically corresponds to the orientation and depth of insertion of a probe 98 of a disposable probe assembly 100 of the MRI biopsy device 14 or of a sleeve trocar 102 with inserted introducer obturator 104 . For clarity, the term Z-axis may be used interchangeably with “axis of penetration”, although the latter may or may not be orthogonal to the spatial coordinates used to locate an insertion point on the patient. Versions of the localization fixture 16 described herein allow a nonorthogonal axis of penetration to the X-Y axis to a lesion at a convenient or clinically beneficial angle. An origin of the spatial coordinates may be imaging the dents imparted to the tissue by the lateral fence 94 . Alternatively, a disposable fiducial pointer 106 held by a fiducial holder 108 is filled with an MRI imagable material (e.g., KY jelly, saline, gadolinium) and sealed with a cap 110 .
[0036] The probe 98 , sleeve trocar 102 and fiducial pointer 106 are guided by the localization fixture 16 . With particular reference to FIG. 2 , a lateral fence supported pedestal 120 spatially positions left and right primary targeting rails 121 , 122 that in turn guide the fiducial pointer 106 , the sleeve/trocar 102 , or the probe 98 of the biopsy device 14 ( FIG. 1 ). The primary targeting rails 121 , 122 each include an attachment axle 124 that receives in either a left or right side axle hub 125 of a (Y-axis) height yoke 126 that is vertically adjustable upon a pedestal main body 128 , that in turn is laterally adjustable upon the lateral fence 94 . Alternatively, a breast coil may enable mounting the pedestal main body on the medial plate 90 for accessing medially. The pedestal main body 128 includes a proximal upright rectangular column 132 with a thinner wall 134 projecting from its distal side that flares laterally outward (defining left and right vertical rectangular slots 136 , 138 ) as part of a bracket 140 with top and bottom hanger arms 144 , 146 that slide laterally respectively on a top track 148 and a proximally open lower track 150 formed in the lateral fence 94 . A lateral (X-axis) adjustment lever 151 may be raised to lift its distal end 149 out of engagement with a bottom track 147 formed in the lateral fence 94 as the lateral adjustment lever 151 is repositioned to the left or right to a desired location with reference to a lateral measurement guide 145 .
[0037] The height yoke 126 is a rectangular cuff interrupted in a mid-portion of a distal side to form locking left and right hands 152 respectively which ride vertically in the left and right vertical rectangular slots 136 , 138 . The locking left and right hands 152 have respective ridged proximal surfaces (not shown) that are selectively drawn proximally into locking engagement by a height locking lever 156 with a ridged surface 158 on a proximal side of each vertical rectangular slot 136 , 138 . Lifting the height locking lever 156 takes the height yoke 126 out of locking engagement to the pedestal main body 128 as the height yoke 126 is vertically repositioned. For height adjustment, the proximal top surface of the height yoke 126 serves as a sight 160 to read a height measurement scale 162 presented on a proximal surface of the height locking lever 156 .
[0038] The attachment axle 124 allows rotation so that an axis of penetration may include an upward or downward trajectory. In the illustrative version, proximal corners of the height yoke 126 include angle detents 164 (e.g., −15°, 0°, +15°) that are selectable by an angle lock lever 166 . The primary targeting rail 122 includes a distal detent 167 that serves as a home reference for the fiducial holder 108 ( FIG. 1 ).
[0039] In FIGS. 3-4 , a guidance assembly 200 , that may be attached to the lateral fence supported pedestal 120 of FIG. 2 , includes a cradle 202 whose upper lateral side 202 a flares upwardly to engage a bottom channel 203 of the primary targeting rail 122 . A lower lateral side 202 b flares horizontally to provide a holster guide track 204 that underlies the axis of penetration. To provide additional guidance to the MRI biopsy device 14 ( FIG. 1 ), a secondary targeting rail 206 includes a lateral channel 208 that is guided along a longitudinal guide tab 210 of the primary targeting rail 122 . When fully engaged thereon, a pawl 212 pivoting under urging of a pawl spring 214 about a vertical pawl pin 216 in a lateral window 218 proximally positioned in the secondary targeting rail 206 drops into a proximal detent 220 proximally positioned on the primary targeting rail 122 . The pawl spring 214 may maintain the pawl 212 in a neutral position that serves in both assembly and later removal of the secondary targeting rail 206 or comprises a pair of opposing pawl springs (not shown) for that purpose.
[0040] In FIGS. 4-5 , the sleeve trocar 102 includes a hollow shaft (or cannula) 223 that is proximally attached to a cylindrical hub 224 and has a lateral aperture 226 proximate to an open distal end 228 . The cylindrical hub 224 has an exteriorly presented thumbwheel 230 for rotating the lateral aperture 226 . The cylindrical hub 224 has an interior recess 232 that encompasses a duckbill seal 234 , wiper seal 236 and a seal retainer 238 to provide a fluid seal when the shaft 223 is empty and for sealing to the inserted introducer obturator 104 .
[0041] The introducer obturator 104 advantageously incorporates a number of components with corresponding features. A hollow shaft 242 includes a fluid lumen 244 that communicates between an imagable side notch 246 and a proximal port 248 . The hollow shaft 242 is longitudinally sized to extend when fully engaging a piercing tip 249 out of the distal end 228 of the sleeve trocar 102 . An obturator handle 250 encompasses the proximal port 248 and includes a locking feature 252 , which includes a visible angle indicator 254 , that engages the sleeve thumbwheel 230 to ensure that the imagable side notch 246 is registered to the lateral aperture 226 in the sleeve trocar 102 . An obturator seal cap 256 may be engaged proximally into the obturator handle 250 to close the fluid lumen 244 . The obturator seal cap 256 includes a locking or locating feature 258 that includes a visible angle indicator 259 that corresponds with the visible angle indicator 254 on the obturator thumbwheel cap 230 . The obturator seal cap 256 may be fashioned from either a rigid, soft, or elastomeric material.
[0042] Returning to FIGS. 3 , 4 , the sleeve trocar 102 is guided, during penetration of tissue, by a sleeve mount 260 having a sleeve hub 262 that receives the cylindrical hub 224 of the sleeve trocar 102 . The sleeve mount 260 has a lateral sleeve hub channel 264 that slides along top and bottom guide flanges 266 , 268 of the secondary targeting rail 206 , each having an aligned and recess ridged, ratcheting surface 270 that interacts with a respective top and bottom ratcheting feature 272 , 274 on respective top and bottom rail lock rocker latches 276 , 278 that are engaged by respective top and bottom latch pins 280 , 282 in respective sides of the sleeve mount 260 . The ratcheting features 272 , 274 are proximally ramped such as to allow distal movement. Distal portions of each rail lock rocker latches 276 , 278 are biased away from the sleeve mount 260 by respective rail lock compression springs 284 , 286 to bias the ratcheting features 272 , 274 into contact with the ridges surfaces 270 of the guide flanges 266 , 268 . Simultaneous depression of the rail lock rocker latches 276 , 278 allow the sleeve mount 260 to be drawn proximally, withdrawing any sleeve trocar 102 supported therein, until the sleeve mount 260 reaches a proximal end of the secondary targeting rail 206 , whereupon the sleeve mount 260 rotates the pawl 212 clockwise (as viewed from the top) and is thus engaged to the secondary targeting rail 206 as the secondary targeting rail 206 is unlocked from the primary targeting rail 122 , causing removal therefrom with continued proximal movement.
[0043] Before mounting the secondary targeting rail 206 onto the primary targeting rail 122 in the first place, the sleeve mount 260 is advantageously adjustably positioned on the secondary targeting rail 206 to set a desired depth of penetration. In particular, a depth guide 290 is formed by a crescent-shaped depth indicator 292 having a lateral channel 296 shaped to engage the top and bottom guide flanges 266 , 268 . Forward ramped surfaces 298 on the top and bottom of the lateral channel 296 are positioned to engage the ridged ratcheting surfaces 270 on the secondary targeting rail 206 , allowing assembly by inserting the depth indicator 292 from a distal end of the secondary targeting rail 206 . Frictional engagement thereafter resists further proximal movement and strongly opposes any distal movement, especially from a depth lead screw 300 of the depth guide 290 , whose distal end 302 rotates within an outboard hole 304 in the depth indicator 292 and whose proximal end deflects laterally as a depth actuator lever 305 is used to rotate and longitudinally position the depth lead screw 300 therein. A mid portion of the depth lead screw 300 is received in a longitudinal through hole 306 formed in the sleeve mount 260 outboard of its lateral channel 208 . For coarse depth adjustment, outer lead threads 307 on the depth lead screw 300 selectively engage the sleeve mount 260 until top and bottom coarse adjust buttons 308 , 310 are inwardly depressed into the sleeve mount 260 , compressing respective top and bottom coarse adjust compression springs 312 , 314 . Each coarse adjust button 308 , 310 includes a respective vertically elongate aperture 316 , 318 whose inward surface presents a worm gear segment 320 , 322 to engage the outer lead threads 307 on the depth lead screw 300 when urged into engagement by relaxed coarse adjust compression screws 312 , 314 .
[0044] Returning to FIG. 3 , the thumbwheel 230 is depicted as engaged to the sleeve hug 262 of the sleeve mount 260 with other portions of the sleeve trocar 102 omitted. Application s consistent with the present invention may include a probe of an MRI biopsy device that includes a piercing tip or that otherwise is used without passing through a hollow shaft (cannula) 223 . As such, the thumbwheel with similar sealing members may be incorporated into the sleeve mount 260 .
[0045] In FIGS. 6-7 , the MRI biopsy device 14 has the disposable probe assembly 100 depicted detached from the reusable holster portion 32 and with the remote keypad 62 released from the reusable holster portion 32 . The sheathed cable 27 is joined to an underside of the reusable holster portion 32 distal to the aft end thumbwheel 63 to enhance balance and support of the reusable holster portion, which in turn may be engaged to the holster guide track 204 ( FIG. 4 ) by an I-beam shaped holster rail 324 whose upper surface 326 is engaged within a bottom channel 328 of a holster base plate 330 . A ridged member 331 upon the holster base plate 330 guides the disposable probe assembly 100 during engagement. A narrowed upper distal surface 332 of the holster rail 324 also engages downward gripping flanges 334 extending downward just proximal to a distal thumbwheel 336 of the disposable probe assembly 100 . An under slung shell 337 is fastened to the proximal undersurface portion of the holster base plate 330 .
[0046] The disposable probe assembly 100 also has an undersurface that backwardly slides into engagement with the reusable holster portion 32 . In particular, a narrowed proximal end 338 is formed into an upper cover 340 with a distal locking arm 342 separated from the upper cover 340 on each side except proximally to present an unlocking button 344 on an exposed surface 346 of the upper cover 340 that is depressed to disengage a locking surface 348 ( FIG. 6 ) from a distal lip 350 of a distally open receiving aperture 352 in the reusable holster portion 32 of the holster plate 330 .
[0047] A recessed deck 354 in an upper proximal surface of a proximal top cover 356 of the reusable holster portion 32 is shaped to receive the remote keypad 62 . A lower shell 358 mates to the proximal top cover 356 . The proximal top cover 356 also defines the upper portion of the receiving aperture 352 . The recessed deck 354 has a front guide hole 360 and a back locking aperture 362 registered to respectively receive a front tooth 363 and a flexing unlock tab 364 at an aft end of the remote keypad 62 to selectively engage and disengage the keypad 62 from the reusable holster portion 32 . The keypad 62 also includes a translation rocker button 366 that has a distal advance, a default neutral, and an aft retract command position. An aft button 368 may be programmed for mode functions such as saline flush.
[0048] With particular reference to FIG. 6 , the disposable probe assembly 100 has a plurality of interconnections presented on an aft docking end 370 . A rightward canted vacuum hose nib 372 is positioned to receive a vacuum conduit (not shown) that would be gripped by a friction clip 373 extending under and aft thereof to prevent inadvertent release. A right side slot 374 is distally open and formed between the holster base plate 330 and proximal top cover 356 to receive such a vacuum conduit as the disposable probe assembly 100 is engaged to the reusable holster portion 32 . A center splined driveshaft 375 engages the aft end thumbwheel 63 and communicates with the distal thumbwheel 336 to rotate a side aperture 376 in probe 98 to a desired side, as visually confirmed by an arrow indicator 378 on the distal thumbwheel 336 . A right splined driveshaft 380 effects cutter translation and a left splined driveshaft 382 effects cutter rotation.
[0049] The distal thumbwheel 336 and probe 98 are mounted to a cylindrical hub 384 , which is a distal portion of the lower shell 358 that extends beyond the mating with the upper cover 340 . A sample through hole 386 communicates through the cylindrical hub 384 for receiving a rotating and translating cutter tube 388 ( FIG. 9 ) that enters the probe 98 and for receiving tissue samples (not shown) deposited by a retracting cutter tube 388 . As the cutter tube 388 fully retracts into a carriage cavity 390 formed between the upper cover 340 and proximal portion of the lower shell 358 , a distally extending tip 392 from a vacuum tube 394 encompassed by the cutter tube 388 dislodges the retracted tissue sample onto a sample retrieval platform 396 , which is a relieved area between the upper cover 340 and the cylindrical hub 384 .
[0050] In FIG. 8 , it should be appreciated that the sheathed cable 27 connects to the holster base plate 330 and communicates a single mechanical drive rotation to a fixed ratio transmission 398 mounted to the holster base plate 330 and electrically communicates with an encoder 400 coupled to the fixed ratio transmission 398 aft of the receiving aperture 352 . The sheathed cable 27 also communicates electrically with the display area 61 via a wire bundle (not shown) and with the keypad 62 via a cable assembly 402 , the latter including a strain relief bracket 404 that grips a keypad cable 406 and is fastened proximate to the sheathed cable 27 . The fixed ratio transmission 398 has a pass-through port 408 that receives a distal end the center splined driveshaft 375 ( FIG. 6 ) to rotatingly engage a proximally received beveled shaft 410 distally presented by the aft end thumbwheel 63 and sealed by an O-ring 412 . A right port 414 distally presented by the fixed ratio transmission 398 engages for rotation the right splined driveshaft 380 from the disposable probe assembly 100 for advancing and retracting (“translation”) the cutter tube 388 . A left port 416 distally presented by the fixed ratio transmission 398 engages for rotation the left splined driveshaft 382 from the disposable probe assembly 100 for rotating the cutter tube 388 when a distal cutting edge of the cutter tube 388 slides past the side aperture 376 of the probe 98 .
[0051] In FIGS. 9-10 , the carriage cavity 390 of the disposable probe assembly 100 includes a cutter carriage 418 having a threaded longitudinal bore 420 that encompasses an elongate translation shaft 422 whose proximal termination is the right splined driveshaft 380 supported by an aft right cylindrical bearing 424 received in an aft wall 425 of the lower shell 358 . A race about the outer circumference of the cylindrical bearing 424 receives an O-ring 426 . A distal end 428 of the threaded translation shaft 422 rotates within a distal right cylindrical bearing 430 engaged to a forward wall 432 of the lower shell 358 . A race about the outer circumference of the cylindrical bearing 430 receives an O-ring 434 . A threaded central portion 436 of the elongate translation shaft 422 resides between an unthreaded distal over-run portion 438 and an unthreaded proximal over-run portion 440 , both sized to allow the threaded longitudinal bore 420 of the cutter carriage 418 to disengage from the threaded central portion 436 .
[0052] A distal compression spring 442 and a proximal compression spring 444 respectively reside on the unthreaded distal and proximal over-run portions 438 , 440 to urge the threaded longitudinal bore 420 of the cutter carriage 418 back into engagement with the threaded central portion 436 upon reversal of rotation of the elongate translation shaft 422 . In particular, the cutter carriage 418 includes a top longitudinal channel 446 that slidingly engages an undersurface of the upper cover 340 (not shown) and a bottom longitudinal guide 448 that engages a longitudinal track 450 on a top surface of the lower shell 358 . Thus rotationally constrained, rotation of the elongate translation shaft 422 causes corresponding longitudinal translation of the cutter carriage 418 with distal and aft pairs of gripping flanges 452 , 454 maintained laterally to the left to engage respectively distal and proximal races 456 , 458 formed on each side of a toothed portion 460 of a cutter spur gear 462 , which has a longitudinal bore for applying vacuum.
[0053] To that end, the vacuum hose nib 372 is attached to a mounting structure 464 that is gripped between the upper cover 340 and the lower shell 358 to present an orifice 466 within the carriage cavity 390 that is aligned with the longitudinal bore of the cutter gear 462 and that is in fluid communication with the vacuum hose nib 372 .
[0054] With particular reference to FIG. 10 , the proximal end of the vacuum tube 394 is received in the orifice 466 . A rectangular guide 467 supports the distally extending tip 392 of the vacuum tube 394 and is engaged between the upper cover 340 and the lower shell 358 . The cutter tube 388 encompasses and translates relative to the vacuum tube 394 . A seal cap 468 attached to a proximal end of the cutter gear 462 dynamically seals to the outer circumference of the vacuum tube 394 so that vacuum pressure supplied proximate to the distally extending tip 392 is not released within the carriage cavity 390 . The cutter tube 388 is advanced around the open distal end of the vacuum tube 394 , across the sample retrieval platform 396 to seal against a back seal 470 that substantially closes a proximal opening 472 into a sleeve union 474 that rotates within the cylindrical hub 384 . The sleeve union 474 has a distal end 476 engaged for rotation with the distal thumbwheel 336 . Distal and proximal O-rings 478 , 480 reside respectively within distal and proximal races 482 , 484 that straddle a lateral passage 486 of the sleeve union 474 to provide a degree of frictional resistance against inadvertent rotation and advantageously seal the lateral passage 486 for vacuum assistance to prolapse tissue and to retract samples. A noncircular opening 488 is centered in a distal face of the distal thumbwheel 336 . A proximal end of a probe tube 490 of the probe 98 extends through the noncircular opening 488 to receive a distal end of the cutter tube 388 . A lateral tube 492 attached along its length to the probe tube 490 communicates with the lateral passage 486 of the union sleeve 474 . The lateral tube 492 defines a lateral lumen that communicates with the a cutter lumen defined by the probe tube 490 /cutter tube 388 below the side aperture 376 through lumen holes 494 ( FIG. 9 ).
[0055] The center splined driveshaft 375 that is turned by the aft end thumbwheel 63 rotates in turn a shaft 496 whose keyed distal end 498 in turn is engaged to and rotates a pinion gear 500 that is in gear engagement to a proximal spur gear 502 that forms an outer proximal circumference of the sleeve union 474 . A cylindrical distal tip 504 of the keyed distal end 498 rotates within an axle hole (not shown) in the lower shell 358 . Rotation of the aft end thumbwheel 63 thus rotates the probe 98 .
[0056] A distal elbow pneumatic fitting 506 is supported in the lower shell 358 to have an upper end 508 communicating with the lateral passage 486 of the sleeve union 474 and an aft end 510 attached to a vent pneumatic conduit 512 supported by the lower shell 358 . The other end of the vent pneumatic conduit 512 is attached to a distal end 514 of a proximal elbow pneumatic fitting 516 whose lateral end 518 is open to atmosphere. Sizing of various components that vent atmospheric pressure through the lumen holes 494 from the lateral end 518 are such that a tissue sample may be withdrawn through the probe tube 490 . Yet a greater pneumatic draw of air through the vacuum hose nib 372 prior to severing a tissue sample results in a sufficient low pressure at the side aperture 376 to prolapse tissue for severing.
[0057] An elongate rotation shaft 520 proximally terminates in the left splined driveshaft 382 that is supported for rotation by a left aft cylindrical bearing 522 having a race about an outer circumference that receives an O-ring 524 and is received in the aft wall 425 of the lower shell 358 . A distal end 526 of the elongate rotation shaft 520 is received for rotation in a left distal cylindrical bearing 528 having a race about an outer circumference that receives an O-ring 530 and that is received within the front wall 425 of the lower shell 358 . As the cutter carriage 418 advances to position the cutter tube 388 to slide past the side aperture 376 , the cutter spur gear 460 engages a spur gear portion 532 of the elongate rotation shaft 520 . Rotating the cutter tube 388 in proportion to an amount of rotation advantages secures an effective severing of tissue. Eliminating rotation when not severing advantageously enhances retraction of tissue sample retraction.
[0058] In use, in FIG. 11 , the localization fixture 16 has been installed into the breast coil 18 . The guidance assembly 200 has been preset for a desired insertion point, a desired axis of penetration, and a depth of penetration. After the sleeve trocar 102 /introducer obturator 104 have been inserted and imaged to confirm placement, the introducer obturator 104 is removed and the probe 98 of the biopsy device 14 is inserted, as depicted in FIG. 12 . The shape of the sleeve trocar 102 aligns the probe 98 , visually assisted by lining up the arrow indicator 378 on the distal thumbwheel 336 with the visible angle indicator on the thumbwheel 230 of the sleeve trocar 102 . The surgeon may effect operation of the biopsy device 14 by depressing the translation rocker button 366 and aft button 368 on the keypad 62 while referencing status information about the biopsy device 14 on the display area 61 . In FIG. 13 , the display area 61 advantageously includes a cutter position bar graph 534 having distal and proximal indications 536 , 538 that may be compared with how many light segments 540 have been illuminated to indicate progress of the cutter tube 388 relative to the side aperture 376 . The aft button 368 may be toggled to cycle the biopsy device 14 through three modes, indicated by a position LED indicator 542 , a sample LED indicator 544 , and a clear LED indicator 546 with a corresponding label that graphically depicts operation of the biopsy device in that mode. In particular, a position mode depiction 548 illustrates that the cutter tube 388 may be advanced and retracted, for instance, closing the side aperture 376 prior to insertion of the probe 98 into the sleeve trocar 102 . In a sample mode depiction 550 , vacuum assistance is implemented, drawing sufficient air through the cutter tube 388 to prolapse tissue into the open side aperture 376 that is maintained while translating the cutter tube 388 . In a clear mode depiction 552 , vacuum is maintained while fully retracting the cutter tube 388 to retract a tissue sample. In FIG. 14 , a marker device 548 is deployed through the sample through hole 386 in the cylindrical hub 388 .
[0059] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein, will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
[0060] While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.
[0061] For example, while closed loop feedback sensing of a component that is related to cutter tube position has various advantages, determination of cutter position may be achieved in other ways consistent with the present invention. For instance, loading on drive components may be sensed at either full advancement and/or full retraction which are used to calibrate an estimate cutter position based on duration of a translation command.
[0062] As another example, rather than discrete LED indicators and labeled depictions, applications consistent with aspects of the invention may include a graphical display (e.g., organic liquid crystal display) that is capable of interactive presentations of intuitive instrument status information. Alternatively or in addition, a touch screen capability may be incorporated to allow instrument control input as well as display.
[0063] For another example, applications consistent with aspects of the present invention may be used in conjunction with different diagnostic imaging modalities (e.g., ultrasonic, computed tomography (CT).
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A magnetic resonance imaging (MRI) compatible core biopsy system uses a biopsy device having intuitive graphical displays and a detachable remote keypad that advantageously allows convenient control even within the close confines afforded by a localization fixture installed within a breast coil that localizes a patient's breast and guides a probe of the biopsy device relative to the localized breast. A control module for interactive control and power generation are remotely positioned and communicate and transmit rotational mechanical energy via sheathed cable.
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FIELD OF THE INVENTION
This invention relates to memory devices and more particularly, to disc type storage drives that incorporate magnetic or optical discs as an information storage medium.
BACKGROUND OF THE INVENTION
Electronic members are used to store large quantities of digital data and other information used in computers and other computerized electronic devices in which large amounts of information need to be recorded and/or retrieved and displayed upon a cathode ray tube or other video display device. In more recent years, forms of digital storage devices have been incorporated within computerized entertainment devices such as those used for presenting video information, pictures as well as digitally stored music. A typical form of storage device employs a rotatable storage medium or "disc", either permanently housed within the device or which is removable and may be removed and replaced by another disc; and a transducer or "head" by means of which the information stored on the disc is interrogated or "read out" and coupled to other devices in the system. Disc drives of this type include magnetic disc drives in which the discs are of magnetic material and in which the information is stored in the form of magnetic flux, whereby the information is read out by magnetic type transducer means, and optical disc drives in which the information is stored in the form of pits or other broader optical discontinuities in the disc material and in which a readout is accomplished by light transducer means, typically a laser diode and photodetector combination. The information is arranged and stored in the "tracks" located on the disc. Those tracks may be in the form of a continuous spiral track or a series of concentric circular tracks.
Information is stored by filling the disc tracks with closely spaced disc continuities; so called "pits" for optical discs, magnetic flux reversals for magnetic discs. In a typical arrangement for an optical disc, there may be approximately 5,000-10,000 of such "pits" in each centimeter of circumferential track length.
The information stored is retrieved by a pick-up transducer, suitably a servo driven head which contains a sensor, either optical or magnetic. The servo positions the head over a selected track and the sensor reads the information previously stored on that track. In additional to reading the information on a particular track, a provision in the system provides rapid switching between one track and another, which may be spaced some distance apart on the disc; an action that is referred to as "seeking" in magnetic disc drives and/or "track jumping" in optical disc parlance. In the operation of a computerized device a "command" is given to procure certain information from within storage. Given the identifying information, the command causes the sensor to seek the track location in which the particular information is stored, following which, the head or sensor retrieves the stored information and returns it to the other electronic circuits within the computer for further processing or for display.
In particular, interactive video used that is often used for games, education, training, and the like, frequently requires a "branching" function; that is, instantaneous switching to a new scenario under user control. The branching is accomplished by interleaving a number of scenarios on the disc track. The user initiates a branch by causing the video disc player to execute "track jumps" in a sequence which selects one of the interleaved scenarios. In order to create a steady video image, the track jumps must be accomplished within the video display's vertical retrace inverval and the number of tracks in each jump must be precisely controlled.
The foregoing retrieval operations require that the head and sensor be moved rapidly in a radial direction with a controlled motion so that the sensor comes to rest over the desired track. Various technologies for accomplished sensor positioning in this arrangement are known and are in wide use. Those existing techniques are, however, either quite elaborate, typically requiring a separate channel for track jumping which is electronically switched in at the beginning of a track jump, followed by a switch out at the conclusion, or is of crude design in that only short track jumps can be executed with acceptable levels of precision. The present invention provides a relatively simple means to permit highly accurate track jumps of any length.
With existing technology, the first approach to head positioning is accomplished in a three-step process. First, the tracking servo loop is opened and an "accelerate signal" is applied to the sensor head. Second, at the mid-point of head travel between the two track positions, the signal applied to the sensor head is changed to a "decelerate" signal. And, at the conclusion of travel, the "decelerate" signal is removed and the tracking servo loop is closed which, ideally, leaves the sensor positioned over the correct disc track. Because there is no closed loop control of the sensor head during a track jump, this approach is believed to be suited only to short jumps.
The existing technology for long "jumps" or "seeks" contains some means for monitoring the movement of the sensor as it travels from its start position to the selected disc track. This uses a closed loop control insuring that the sensor remains on course, so to speak, and arrives at the correct track, even after lengthy travel. Typically, the velocity of the sensor movement is a parameter used for head positioning control. In addition, a technique for sampling position error once for each track crossing is presented in U.S. Pat. No. 4,547,822, granted to Stewart Brown, the present application.
An advantage of the present invention is that it avoids the need for an additional channel and the accompanying electronic hardware as in the case of the prior drives.
A principle object of the invention is to provide an improved control for positioning a moveable disc head transducer. A further object is to provide accurate track jumps under adverse conditions such as video disc with dust, fingerprints, etc., on the optical surface. A further object is to provide a disc head control circuit that accurately positions the head even over long jumps and is less expensive than existing techniques that perform that function. A still additional object is to provide a lowcost disc head position controller capable of accurately positioning the head.
SUMMARY
In accordance with the aforecited objects, the disc drive of the invention includes a reference signal generating means for sythesizing a signal that is a real time analogue representation of a "perfect signal", one that would be outputted from the tracking sensor during a perfect movement of the head to the specified disc track and, in effect, simulates the perfect signal as a reference. This reference signal is combined in a subtractive relationship with the actual signal generated by the sensor during its movement. The resulting difference signal is applied to the input of the tracking servo and functions as an error signal to control the sensor position during the track jump. As is apparent, in this system the existing tracking servo is employed, avoiding the need for an additional channel.
A further important advantage is that this difference signal is a position difference signal, and it is valid for a high percentage of time (as opposed to a signal derived only once per track crossing).
The foregoing advantages and objects of the invention, together with additional advantages, are better understood by giving consideration to the detailed description of the preferred embodiment, which follows in this specification, taken together with the illustrations thereof presented in the figures of the drawings.
DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a block diagram of the tracking servo control system in accordance with the invention;
FIG. 2 is a diagrammatic depiction of the servo head position relative to time when crossing a plurality of tracks of a disc, or the like;
FIG. 3 is a position versus time waveform showing an idealized or perfect signal from the sensor head of the system of FIG. 1, with portions of the waveforms highlighted in solid and open blocks, the waveform being correlated to the servo head position of FIG. 2 by vertical broken lines;
FIG. 4 is a partial analog waveform showing a reference signal derived from the waveform of FIG. 2, and correlated thereto by vertical broken lines;
FIG. 5a is a partial graphical depiction of a digital control signal for the track and hold circuit of the system of FIG. 1 correlated in time to the waveforms thereabove by vertical broken lines;
FIG. 5b is a partial graphical depiction of a digital control signal for the normal/invert circuit of the system of FIG. 1 correlated in time to the waveforms and control signals thereabove by vertical broken lines;
FIG. 5c is a partial graphical depiction of a digital control signal for the accelerate positive signal generated by the microprocessor circuit of the system of FIG. 1 correlated in time to the waveforms and control signals thereabove by vertical broken lines; and
FIG. 5d is a partial graphical depiction of a digital control signal for the accelerate negative signal generated by the microprocessor circuit of the system of FIG. 1 correlated in time to the waveforms and control signals thereabove by vertical broken lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In a preferred form, the embodiment contains the sensor and head 1; a servo driver 3; and a transfer function generator 5. A positive accelerator signal input 7 and an accelerate negative or a decelerate signal input 9 are included and are coupled to the corresponding inputs of driver 3. The sensor head 1, contains an output 11, the tracking signal output which output 11 is designated "E", and is a serve head tracking signal. The elements described are found in conventional disc drives. As those skilled in the art appreciate, the various mechanical details of the disc or the sensor head positioning means and other aspects of the conventional structure depicted in block diagram form, may be of any conventional type and, hence, are not illustrated in detail in the drawings and are not further described.
A digital-to-analogue converter 13, has an input 15, coupled to associated equipment which equipment may include a microprocessor or other logic circuits for performance of the function to be described, which equipment is represented by dash line 17 and an output with the output 19 being, coupled by resistor 21 to the input 23 of track and hold circuit 25. In the drawings, the output 19 is designated "R", which is a reference signal as will be hereafter described. Output 27 of the track and hold circuit 25 is connected to the input of an invert/normal circuit 29. In turn, the output 31 of invert/normal 29 is coupled to the input of the servo transfer circuit 5. A second input 33 to track and hold circuit 25 is coupled to the associated equipment 17. A second input 35 to invert/normal circuit 29 is coupled to the output of the associated circuit 17. Circuit 17, represented in block form, contains the microprocessor and its associated program. The program contains the information which is processed to provide a reference signal in digital form in a waveform that meets the criteria elsewhere described in this specification. The program also contains the commands for applying, at appropriate intervals, a positive accelerate signal to lead 7, a negative accelerate, or decelerate signal to input 9, an invert/normal signal to input 35 and a track and hold signal to input 33.
The trajectory of the sensor head in a perfect jump over eight tracks of the disc, is illustrated in FIG. 2. There is a constant acceleration from the start, T-0, to the midpoint, T/2, followed by constant deceleration from the mid-point of travel, to the final position on the 8th track, T-End; FIG. 3 illustrates a frequency modulated quasi sinusoidal wave form outputted from the tracking sensor during the hypothetical perfect track jump in the example of FIG. 2.
FIG. 2 depicts a curve of servo head position relative to time as a function of track position, with the track being designated track "0" through track "8", this being used as an example to show an eight track jump of the servo head. This jump takes place between the times designated T-0 and T-END, with the mid-point of the cycle designated T/2.
FIG. 3 depicts an idealized or perfect waveform 50, which would be the output waveform from the servo head sensor 1 under ideal or perfect conditions. The waveform 50 is of a generally quasi-sinusoidal configuration, with this waveform 50 having segments thereof shown in blackened or solid blocks, e.g. 51-59, and other segments of the waveform depicted in open blocks, e.g., 60-67. The significance of this particular marking of the waveform relates to the correlation of the waveform segment to the track position of FIG. 2. For example, all solid or darkened blocks 51-59 depict segments of the waveform 50 relative to an "on-track position", while the open blocks 60-67 depict segments of the waveform 50 which correlate to the "inter-track" positions, that is, the servo head is between tracks of the disc.
With respect to the highlighted segments of waveform 50, the on-track segments 51-59 and the inter-track segments 60-67 are valid analogues of the instantaneous position of the servo head sensor 1. It is to be noted that the segments 51-59 have an ascending or positive slope, while the segments 60-67 have a descending or negative slope. These on-track and inter-track segments are then replicated to synthesize portions of a reference signal, in digital form, which portions are stored in the associated microprocessor circuit 17. The portions of the waveform 50 between these segments, that is, the tops and bottoms of the quasi-sinusoidal waveform 50, do not contain much useful information and, accordingly, those waveform portions are not used in connection with the generation of the reference signal.
Useful information extracted from this waveform 50, is shown by the truncated waveform of FIG. 4, which depicts the reference signal. By correlating, via the vertical broken lines, it can be seen, that solid line segment 51 of FIG. 3 corresponds to the segment 51a of FIG. 4, the open block segment 60 of waveform 50 corresponds to the segment 60a of FIG. 4, segment 52 corresponds to segment 52a, etc., with segments 67 and 59 of waveform 50 corresponding to segments 67a and 59a, respectively, in FIG. 4.
The on-track segments 51-59 and the inter-track segments 60-67 are replicated to synthesize the reference signal of FIG. 4 indicative of the perfect waveform. The inter-track segments 60-67 have a polarity opposite that of track segments 51-59 and, accordingly, for use, provision is made in the circuitry for taking this into consideration, that is, invert/normal circuit 29 is triggered by the associated circuit 17 to effect polarity reversal during the time the inter-track segments 60-67 are being used.
The reference signal R is depicted in FIG. 4. The reference signal is presented, as a digital signal, from control circuit 17, as an input 15 to the digital-to-analogue converter 13 by the microprocessor as shown in FIG. 1. Alternatively, if the disc drive microprocessor is too slow or too busy, the digital-to-analogue converter can be driven by hardware that consists of an electronic counter, a read-only memory and associated logic, the exact details of which, including its assembly, are apparent to those skilled in the art from the foregoing description.
The analogue equivalent, designated as reference signal "R" in FIG. 1, is outputted from the digital to analogue converter 13 at 19, and is then subtracted from the head sensor tracking signal "E" appearing at output 11 of the head sensor 1, and the resulting difference signal is inputted via lead 23 to the input of the track and hold circuit 25, and this difference is presented at output 27 to the input of the inverter 29. The output 31 of inverter 29 is a polarity-correlated error signal "e", which is applied to the input of servo circuit 5.
In operation, at such time as the associated control circuitry 17 determines that a track jump is to occur, the elements of that control circuit contain information as to the present position of the sensor head and the position to which the sensor head is to be moved, such as from track number "0" to track number "8", as shown in FIG. 2, a jump of 8 tracks in the example discussed in the preceding figures. It is to be understood that any number of tracks may be jumped, with corresponding information relating to all permitted track jumps, programmed or stored within the control circuitry 17.
At the time a jump is to be performed, the control circuitry 17 at that time issues an accelerate signal to driver 3 on input 7 in FIG. 1, with the "accelerate signal" represented by waveform 70 in FIG. 5c. As a result, the command causes an open loop acceleration of the servo head. The detailed mechanisms that actually move the head are not illustrated, but are conventional in the disc drive art.
The associated circuitry in control circuit 17 generates digital information that represents, in digital form, the idealized waveform of the type described in connection with FIGS. 3 and 4, which digital information is based on the information as to the present track position and the final track position anticipated after the desired number of tracks to be jumped. In the preferred form, this digital information, on the idealized or perfect jump, is synthesized mathematically and, for example, is of the form R=sin Kt 2 , where t represents time and K represents an empirically determined constant. Thus, the control circuitry 17 supplies digital numbers at input 15 of digital-to-analogue converter 13 that are representative of the instantaneous value of reference signal amplitude as of the given point in time. The digital-to-analogue converter 13 converts that digital information into an analogue signal "R", which signal is represented in FIG. 4, which is the output at lead 19.
By reference to FIGS. 3 through 5d, the waveform of FIG. 3 shows relevant time intervals, such as T 0 , T 1 , T 2 , T 3 , etc., which are designated times at which certain events occur, these events being correlated to the time by the vertical broken lines. The track and hold gating signal 33 (in FIG. 1) is depicted as waveform 72 in FIG. 5a, the normal/invert gating signal 35 (in FIG. 1) is depicted as waveform 74 in FIG. 5b, the accelerate positive signal 7 (in FIG. 1) is depicted as waveform 70 in FIG. 5c, and the accelerate negative (or decelerate) signal 9 (in FIG. 1) is depicted as waveform 75 in FIG. 5d.
During the time interval between the start T 0 and T 1 , the difference between reference signal "R" at 19 and the servo head tracking signal "E" generated by the head sensor 1 appearing at output lead 11, is applied at input 23 of track and hold circuit 25. The track and hold circuit 25, whose input signal is represented by waveform 50, during this same time interval, is in track condition. Similarly, the normal/invert signal 35, represented by waveform 74, is in a normal state, since the segment 51a is of a positive slope. Of course, as previously described, the accelerate positive signal 35, represented by waveform 70 is on, while the accelerate negative signal, represented by waveform 75, is off.
During the next time interval between T 1 and T 2 , by reference to waveform 50 of FIG. 3, the idealized waveform is at the top, which as shown in FIG. 4, is not used as part of the synthesizing of the idealized or perfect signal waveform. During this time, the microprocessor in circuit 17 issues a hold signal, portion 72a of the waveform 72, which signal is applied at input 33 to place the track/hold circuit 25 in the hold condition. A normal signal of waveform 74 is still applied, along with the accelerate positive signal 7 of waveform 74. During this time, the servo head coasts, maintaining its acceleration.
During the time inverval between time T 2 and time T 3 , the microprocessor places normal/invert circuit 29 in the invert condition (portion 74a) to reverse the polarity of the intertrack error signal. Simultaneously, the signal 33 to the track and hold circuit 25 is changed, as depicted at portion 72b of waveform 72, to issue a tracking signal. The reference signal "E" and sensor tracking signal "E", are, again, used to create a polarity corrected difference or error signal "e", at lead 31, which is input to the function generator 5, and to the driver 3, and during that interval the sensor head is thus again placed under closed loop control to control its motion.
During the time interval between time T 3 and T 4 , the sensor head again coasts. The track and hold signal 33 is changed to hold (portion 72c of waveform 72), with the waveforms 70, 74 and 75 remaining unchanged. The process described is thus repeated.
The process continues until the sensor head is positioned at the mid-point, designated T/2 in FIG. 2, which is midway through the cycle between the initial position T-0 and the intended final position T-END. At that time, the microprocessor in circuitry 17 terminates the accelerate positive signal 7, as shown by portion 70a of waveform 70 in FIG. 5C and, instead, places an accelerate negative signal on lead 9 as represented by the portion 75a of waveform 75 in FIG. 5d. The process continues until the end time T-END, at which time the microprocessor in control circuit 17 terminates the accelerate negative signal 9. The sensor is now located over the correct track, that is, the requisite number of track jumps have been completed.
An alternative to microprocessor control as represented in block 17, is a hardware circuit consisting of logic elements and counters which drives a ROM, of conventional structure that contains the desired data. The ROM is outputted to D/A block 19. With that hardware arrangement, each time that the reference signal passes through zero an output is provided from the ROM. These outputs ("ZEROS") are counted down in order to determined the mid-point of the jump. In addition, a second set of outputs ("PREZEROS") from the ROM is counted down in order to provide a signal occurring prior to the mid-point. This signal is used to initiate deceleration of the head; it is advanced in time to compensate for the unavoidable delays associated with the head. A special group of "PREZEROES" prior to the end of a jump provides an advanced timing for the end of deceleration. A programmed delay in the start of the reference waveform compensates for the starting delay of the head.
If a specific program is written for each jump length, and many different lengths are required, the amount of memory may cause a problem. If available memory is exceeded in a particular design, additional approaches may be used. First, one need store only the program which synthesizes the reference signal for the longest jump that may be required. For shorter jumps, the middle portion of the synthesized signal may be depleted by using the following algorithm: In the program which synthesizes the reference signal R for the longest jump, "max track" make a program jump from [(actual track)/2] to [(max track-actual track)/2]. The result is a reference signal R which is correct for the actual number of tracks in the jump. If the jump is very long, a velocity limited or "flat top" profile may be required. This does not affect the basic technology described. It is noted that if the direction of the jump is reversed, the preceding description is changed by reversing the polarities of the reference signal and acceleration commands from those used in the preceding description.
It is believed that the foregoing description of the preferred embodiment of the invention is suffucient in detail to allow one skilled in the art to make and use the invention. However, it is expressly understood that the invention is not limited to the details disclosed for that purpose. Inasmuch as alternative elements which may be substituted for those described and improvements become apparent to those skilled in the art upon reading this specification. Accordingly, the invention is to be broadly construed within the full scope and the appended claims.
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In a disc drive head positioning system a reference signal generator synthesizes a real time analogue representation of a perfect signal as would be outputted by the tracking sensor during a theoretically perfect movement to the desired disc track, which is used as a reference; the analogue representation is subtractively combined with the actual signal generated by the sensor during movement; and the difference forms the error signal that controls the sensor's position.
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FIELD OF THE INVENTION
[0001] The present invention relates to devices having deployable ultrasound transducers for performing endometrial ablation.
BACKGROUND OF THE INVENTION
[0002] Menorrhagia is a common problem in women that is characterized by extended or irregular menstrual cycles or excessive amounts of bleeding during menstrual cycles. The endometrium is the uterine lining which is responsible for the bleeding that occurs during menstrual cycles, as well as dysfunctional uterine bleeding. Heating to at least superficially destroy the endometrium, also known as endometrial ablation, has been shown to reduce the aforesaid abnormal bleeding. In some cases ablating the endometrium results in cessation of the menstrual bleeding altogether, which may be preferable to the irregular cycles and excessive bleeding that otherwise occur.
[0003] There are many technologies on the market and in clinical trials which utilize a range of energy sources, but the goal for each is the same, i.e., endometrial tissue destruction by thermal cryo-coagulation. For example, Neuwirth, et al, “The Endometrial Ablator: A New Instrument”, Obst. & Gyn., 1994, Vol. 83, No. 5, Part 1, 792-796, performed endometrial ablation using a dextrose-filled balloon device mounted at the end of a carrier catheter and including a heating element inside the balloon. This device also includes a system that monitors the pressure and temperature inside the balloon. Neuwirth, et al. determined that if the surface of the balloon-tissue interface is maintained at about 90° C. for 7-12 minutes, the depth of damage to the endometrium was about 4-10 millimeters. This depth of damage is believed to be clinically acceptable to the extent that such a procedure could be considered as an alternative to surgical procedures, such as hysterectomy.
[0004] High frequency, or radiofrequency (RF), energy has been used to ablate the endometrium as well as cryo-techniques. For example, Prior, et al., “Treatment of Mennorrhagia By Radiofrequency Heating”, Int. J. Hyperthermia, 1991 Vol. 7, No. 2, 213-220, achieved a significant reduction in dysfunctional uterine bleeding using a device that includes a probe having a high frequency RF energy source that is inserted directly into the patient's uterus through the vagina and cervix. The energy source is an RF system having an electrode on the probe and a belt placed around the patient that serves as the return electrode. This RF system is operated at 27.12 MHz at a power of 550 Watts for about 20 minutes and achieves a deeper penetration than the Neuwirth, et al. device, which is an advantage over the Neuwirth, et al. device.
[0005] A system marketed under the tradename THERMACHOICE®, by Ethicon, Inc. of Somerville, N.J., is currently used to perform endometrial ablation and includes a latex balloon filled with a heated dextrose and water solution. The balloon is attached to the distal end of a catheter carrier and the device often delivers satisfactory results. Some patients, however, present a need for deeper and broader endometrial penetration during ablation.
[0006] U.S. Pat. No. 5,620,479 discloses a device for thermal treatment having an array of tubular piezoelectric transducers disposed on a semi-flexible tubular carrier for delivering ultrasound energy directly to tissue to be ablated. The transducers are covered with a sealant coating and there is an outer covering over the sealant coating. This device also includes thermocouple sensors embedded in the sealant coating over each transducer for continuous monitoring of the tissue-applicator interface temperatures for feedback control of the power delivered to the transducers.
[0007] U.S. Pat. No. 5,733,315 also discloses a device for ablating tissue using ultrasound energy, but is adapted specifically for insertion into the rectum for treating the prostate. This device includes one or more ultrasound transducers disposed at least partly about a support tube, each ultrasound transducer having inactivated portions for reducing ultrasound energy directed to the rectal wall. The transducers of this device are also enclosed in a sealant.
[0008] U.S. Pat. No. 5,437,629 discloses an apparatus and method for recirculating heated fluid in the uterus to perform endometrial ablation, without using a balloon. U.S. Pat. No. 5,769,880 discloses an apparatus and method for performing tissue ablation, including endometrial ablation, using bipolar RF energy. This device includes an electrode-carrying member mounted to the distal end of a shaft and an array of electrodes mounted to the surface of the electrode carrying member. A vacuum is utilized to draw out vapors, which are created when the tissue is ablated.
[0009] The foregoing devices and techniques are all either too complex or provide less than optimal results. In addition, they all deliver energy in a general manner, without the ability to control or direct the application of energy in situ to the tissue to be treated. It is further noted that there are no devices specifically adapted for endometrial ablation that use therapeutic ultrasound.
[0010] The device of the present invention addresses the shortcomings of the existing apparatus and process for endometrial ablation by providing a device that delivers ultrasound energy to the endometrial tissue in a controlled and efficient manner by having deployable piezoelectric transducers mounted on movable carriers that are deployed after insertion into the uterus.
SUMMARY OF THE INVENTION
[0011] A device for thermal ablation therapy having emitting means for emitting ultrasound energy capable of heating tissue and moving means for moving the emitting means between an undeployed position, in which the emitting means is in a first orientation which facilitates insertion of the device, and a deployed position, in which the emitting means is in a different second orientation that is selected to efficiently deliver ultrasound energy to the tissue to be ablated. The emitting means is movable from the undeployed position to any one of an infinite number of orientations for efficiently delivering ultrasound energy to the tissue. The moving means is one or more movable carriers and the emitting means is one or more piezoelectric transducers that are securely mounted on the carriers for conjoint movement therewith.
[0012] The moving means includes a rod which has a distal end and a proximal end, and a hollow sleeve, which has a through passage. The rod is slideably received in the through passage and the distal end of the rod is connected to a carrier, whereby sliding movement of the rod moves the piezoelectric transducer or transducers mounted thereon between the undeployed and deployed positions. The piezoelectric transducer and the sleeve are linearly arranged relative to each other when the piezoelectric transducer is in its undeployed position. When the piezoelectric transducer is in its deployed position, the piezoelectric transducer and the sleeve are arranged relative to each other in a non-linear manner. In addition, moving means may also include a handle having a movable part that is connected to the proximal end of the rod for moving the piezoelectric transducer between its undeployed and deployed positions in response to movement of the movable part of the handle.
[0013] In one embodiment, a set of first transducers is mounted linearly on a first carrier and a set of second transducers is mounted linearly on a second carrier. When the first and second transducers are in their undeployed positions, the first transducers are arranged linearly relative to the sleeve and the second transducers are also arranged linearly relative to the sleeve. When the first and second transducers are in their deployed positions, the first transducers are arranged at an angle relative to the sleeve and the second transducers are arranged at an angle relative to the sleeve and relative to said second transducers
[0014] In another embodiment, a plurality of transducers are mounted linearly on a carrier. When the transducers are in their undeployed positions, they are arranged linearly relative to the sleeve and when the transducers are in their deployed positions, they are arranged perpendicularly relative to the sleeve.
[0015] In still another embodiment, a first carrier has a first transducer mounted thereon and a second carrier includes a second transducer mounted thereon and the first and second carriers are pivotable relative to one another such that the first and second transducers are movable between their undeployed and deployed positions. When the first and second transducers are in their undeployed positions the first and second transducers are both arranged linearly relative to the sleeve. When the first and second transducers are in their deployed positions, the first and second transducers are oriented substantially perpendicularly relative to the sleeve and the first and second transducers are arranged linearly relative to one another.
[0016] A method for thermal ablation therapy using ultrasound energy involves positioning an ultrasound device in an undeployed position in which said ultrasound device in is a first orientation which facilitates positioning of the device proximate to tissue to be heated; moving the ultrasound device from its undeployed position to a deployed position which is selected to efficiently deliver ultrasound energy to tissue to be heated; and activating the ultrasound device to emit ultrasound energy for a predetermined period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a better understanding of the present invention, reference is made to the following detailed description of a preferred embodiment of the present invention considered in conjunction with the accompanying drawings, in which:
[0018] [0018]FIG. 1A is a schematic perspective view of a cylindrical piezoelectric transducer used in connection with certain embodiments of the present invention;
[0019] [0019]FIG. 1B is a schematic top plan view of the cylindrical piezoelectric transducer of FIG. 1A showing the direction of ultrasound energy emission therefrom;
[0020] [0020]FIG. 1C is a schematic side elevational view of the cylindrical piezoelectric transducer of FIG. 1A showing the direction of ultrasound energy emission therefrom;
[0021] [0021]FIG. 2A is a schematic perspective view of a hemi-cylindrical piezoelectric transducer used in connection with certain embodiments of the present invention;
[0022] [0022]FIG. 2B is a schematic top plan view of the hemi-cylindrical piezoelectric transducer of FIG. 2A showing the direction of ultrasound energy emission therefrom;
[0023] [0023]FIG. 2C is a schematic side elevational view of the hemi-cylindrical piezoelectric transducer of FIG. 2A showing the direction of ultrasound energy emission therefrom;
[0024] [0024]FIG. 3 is a perspective view of a first embodiment of the device of the present invention, in an undeployed state;
[0025] [0025]FIG. 4 is a top plan view of the first embodiment of the device of FIG. 3;
[0026] [0026]FIG. 5 is a perspective view of the first embodiment of the device of FIG. 3, in a deployed state;
[0027] [0027]FIG. 6 is a schematic cut away view of the first embodiment of the device of FIG. 5, in a delpoyed state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers;
[0028] [0028]FIG. 7 is an exploded perspective view of the major components of the first embodiment of the device of FIG. 3;
[0029] [0029]FIG. 8 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the first embodiment of FIG. 3, with the device in the undeployed state;
[0030] [0030]FIG. 9 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the first embodiment of FIG. 5, with the device in the deployed state;
[0031] [0031]FIG. 10 is a perspective view of a second embodiment of the device of the present invention, in an undeployed state;
[0032] [0032]FIG. 11 is a top plan view of the second embodiment of the device of FIG. 10;
[0033] [0033]FIG. 12 is a perspective view of the second embodiment of the device of FIG. 10, in a deployed state;
[0034] [0034]FIG. 13 is a schematic cut away view of the second embodiment of the device of FIG. 12, in a deployed state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers;
[0035] [0035]FIG. 14 is an exploded perspective view of the major components of the second embodiment of the device of FIG. 10;
[0036] [0036]FIG. 15 is an enlarged perspective cut-away view of the connections between the carrier bar bearing the piezoelectric transducer and the actuator rods of the second embodiment of FIG. 12, with the device in the deployed state;
[0037] FIGS. 16 A- 16 C are sequential perspective cut-away views of the piezoelectric transducer and the actuator rods of the second embodiment of FIG. 11, showing the progressive movement of the transducer and actuator rods from the undeployed state to the deployed state;
[0038] [0038]FIG. 17 is a perspective view of a third embodiment of the device of the present invention, in an undeployed and extended state;
[0039] [0039]FIG. 18 is a top plan view of the third embodiment of the device of FIG. 17;
[0040] [0040]FIG. 19 is a perspective view of the third embodiment of the device of FIG. 17, in a deployed and extended state;
[0041] [0041]FIG. 20 is a perspective view of the third embodiment of the device of FIG. 17, in a deployed and retracted state;
[0042] [0042]FIG. 21 is a schematic cut away view of the first embodiment of the device of FIG. 20, in a delpoyed and retracted state, positioned within the uterus of a patient and showing, schematically, the direction of emission of ultrasound energy from the transducers;
[0043] [0043]FIG. 22 is an exploded perspective view of the major components of the third embodiment of the device of FIG. 17; and
[0044] [0044]FIG. 23 is an enlarged perspective cut-away view of the connections between the carrier bars bearing the piezoelectric transducers and the actuator rods of the third embodiment of FIG. 17, with the device in the deployed state.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The three embodiments of the device of the present invention that are described hereinafter each employ piezoelectric transducers for producing and emitting ultrasound energy to ablate the endometrium of patients experiencing dysfunctional uterine bleeding. The basic construction and operation of piezoelectric transducers are well known and understood to those having ordinary skill in the art. However, in order to facilitate the description of the device present invention, the following discussion provides a general description of piezoelectric transducers of two particular shapes, i.e., cylindrical and hemi-cylindrical, that are most suitable for use with the preferred embodiments of the present invention. Both of these piezoelectric transducers are made of ceramic material such as, PZT4, PZT8, or C5800, each of which is commercially available from ValpeyFischer Corp, Hopkinton, Mass.
[0046] With reference initially to FIGS. 1 A- 1 C a cylindrical piezoelectric transducer 10 is shown schematically from an elevational perspective view (FIG. 1A), from a top plan view (FIG. 1B) and from a front elevational view (FIG. 1C). More particularly, the cylindrical transducer 10 has an inner surface 12 and an outer surface 14 . Both the inner and outer surfaces 12 , 14 are coated with a conductive coating, such as gold, nickel, gold/chromium, etc., to provide electrical contact with the entire area of each surface 12 , 14 , while also avoiding electrical contact therebetween. The conductive coatings may be formed by vapor deposition, or any other suitable method that is known and understood to persons having ordinary skill in the art. An electrically conductive wire 16 is connected at one end thereof to the inner surface 12 and another electrically conductive wire 18 is connected at one end thereof to the outer surface 14 of the cylindrical transducer 10 . Both wires 16 , 18 are preferably a coaxial cable (not shown) and connected at their opposite ends to a source of electrical voltage, more particularly, an RF power source 20 (shown schematically only in FIG. 1A) so that a radiofrequency (RF) electrical voltage can be applied to the cylindrical transducer 10 . The RF power source 20 typically operates at about 1-12 MHz. In operation, as shown schematically by the arrows in FIGS. 1B and 1C, when an RF voltage is applied to the cylindrical transducer 10 , a collimated acoustical wave of ultrasound energy is emitted radially outwardly from the entire outer surface 14 of the cylindrical transducer 10 , in a direction perpendicular to the outer surface 14 .
[0047] With reference now to FIGS. 2 A- 2 C, a hemi-cylindrical piezoelectric transducer 22 is shown schematically from an elevational perspective view (FIG. 2A), from a top plan view (FIG. 2B) and from a front elevational view (FIG. 2C). More particularly, the hemi-cylindrical piezoelectric transducer 22 has an inner surface 24 and an outer surface 26 , both of which are coated with a conductive coating, such as gold, nickel, gold/chromium, etc., to provide electrical contact with the entire area of each surface 24 , 26 , while also avoiding electrical contact therebetween. In a manner similar to that described hereinabove in connection with the cylindrical transducer 10 , electrically conductive wires 28 , 30 , which are preferably a coaxial cable (not shown), are connected to the inner surface 24 and the outer surface 26 , respectively, of the hemi-cylindrical transducer 22 and also to a source of electrical voltage, more particularly, an RF power source 32 (shown schematically only in FIG. 2A) so that a radiofrequency (RF) electrical current can be applied to the hemi-cylindrical transducer 10 . The RF power source 32 typically operates at about 1-12 MHz. In operation, as shown schematically by the arrows in FIGS. 2B and 2C, when an RF voltage is applied to the hemi-cylindrical transducer 22 , a collimated acoustical wave of ultrasound energy is emitted radially outwardly from the entire outer surface 26 of the hemi-cylindrical transducer 22 , in a direction perpendicular to the outer surface 26 .
[0048] When ultrasound energy is absorbed by tissue, it is converted into heat and, therefore, the tissue becomes heated. The RF power is supplied by the RF power sources 20 , 32 at the resonant frequency of the transducers 10 , 22 , respectively, which is proportional to the thickness of each transducer 10 , 22 between the inner and outer surfaces 12 , 24 , 14 , 26 , respectively, thereof. Typically, for use in connection with the present invention, the transducers 10 , 22 should each be constructed having resonant frequencies ranging between about 4 to 12 MHz, preferably about 7 MHz. It is noted that the direction of ultrasound energy emissions from the transducers 10 , 22 are easier to control than the direction of RF energy emissions from bipolar or monopolar RF devices known in the prior art. This is partly because the ultrasound energy emissions are collimated and partly because their direction of travel does not depend upon the placement of an antipolar electrode or ground plate, nor on tissue electrical properties that vary with tissue dessication that occurs during ablation. Since the transducers 10 , 22 are directional, moving the transducer 10 , 22 along a certain angle will also angle the ultrasonic acoustic field and redirect the tissue heating.
[0049] Since all three embodiments of the device of the present invention include one or more piezoelectric transducers of the two general types described hereinabove, and because the transducers are constructed and operated as described hereinabove, the transducers and their components shown in FIGS. 3 - 23 are labeled using variations of the reference numbers used in FIGS. 1 A- 1 C and 2 A- 2 C. For example, where the embodiment being discussed includes one or more cylindrical piezoelectric transducers like that described hereinabove, they will be labeled using reference number “ 10 ” followed by a lower-case letter, for example, 10 a , 10 b , 10 c , etc. Where the embodiment being discussed includes one or more hemi-cylindrical piezoelectric transducers like that described hereinabove, they will be labeled using reference number “ 22 ” followed by a lower-case letter, for example 22 a , 22 b , 22 c , etc. In addition, where the terms “distal” and “proximal” are used hereinafter in connection with the device of the present invention or components thereof, these terms refer to positions that are relative to the user, or surgeon, operating the device.
[0050] With reference now to FIGS. 3 - 9 , a first embodiment of a device 34 in accordance with the present invention is shown. More particularly, FIGS. 3 and 4 show the device 34 in an undeployed state in a perspective view and a top plan view, respectively. FIG. 5 shows a perspective view of the device 34 in a deployed state. The device 34 includes a handle 36 having a fixed arm 38 and a pivotable arm 40 . The pivotable arm 40 is pivotably attached to the fixed arm 38 such that the handle provides means for manual manipulation and operation of the device 34 , as will be described in further detail hereinafter. As seen in FIG. 7, the fixed and pivotable arms 38 , 40 each include connecting means, such as connecting ears 42 , 44 proximate to their distal ends, that cooperate in a manner known in the art to facilitate connecting the pivotable arm 40 to the fixed arm 38 in a pivotable manner. The fixed and pivotable arms 38 , 40 of the first embodiment also each include a finger grip 46 , 48 sized and shaped to receive the fingers of the surgeon therethrough for facilitating manual manipulation and operation of the device 34 . The fixed arm 38 also includes a stop post 50 to prevent the pivotable arm 40 from moving too closely toward the fixed arm 38 , thereby controlling the degree of deployment of the device 34 , as explained in further detail hereinafter.
[0051] With further reference to FIGS. 3, 4, 5 and 7 , the handle 36 also has a hollow shaft 52 that extends from the distal end of the fixed arm 38 . The hollow shaft 52 has a through passage 54 and may be formed integrally with the fixed arm 38 or it may be formed as a separate component and attached to the fixed arm 38 by conventional means, such as welding or gluing. A hollow sleeve 56 also having a through passage 58 is connected to, and extends from, the distal end of the hollow shaft 52 . The hollow sleeve 56 is sized and shaped to conform to the size and shape of the hollow shaft 52 such that their outer diameters are approximately equal and their through passages 54 , 58 , respectively, align with one another.
[0052] The device 34 also includes six hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f that are aligned and grouped with one another at the distal end of the hollow sleeve 56 as shown in FIGS. 3 - 9 . More particularly, as can be seen in FIGS. 5 and 7, three of the hemi-cylindrical transducers 22 a , 22 b , 22 c are securely mounted on a first carrier bar 60 such that their outer surfaces 24 a , 24 b , 24 c all face one direction, which is perpendicular to the length of the first carrier bar 60 . The other three hemi-cylindrical transducers 22 d , 22 e , 22 f are securely mounted on a second carrier bar 62 , such that their outer surfaces 24 d , 24 e , 24 f all face a direction perpendicular to the length of the second carrier bar 62 and opposite that of the three hemi-cylindrical transducers 22 a , 22 b , 22 c mounted on the first carrier bar 60 . It is noted that, when the device 34 is in its undeployed state (see FIGS. 3 and 4), the six hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f are aligned and grouped with one another to form three pairs 22 a - 22 d , 22 b - 22 e , 22 c - 22 f of transducers.
[0053] It is noted that, although not specifically shown in the figures, each of the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f has a pair of electrically conductive wires (not shown) that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the hemi-cylindrical transducer 22 . To protect the wires, which are preferably coaxial cables (not shown), and minimize interference with the manipulation and operation of the device 34 by the surgeon, the aforesaid wires (not shown) can be attached to the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f , and extended through the through passages 54 , 58 of the hollow shaft 52 and hollow sleeve 56 , to the RF power source or sources. As such, each hemi-cylindrical transducer 22 a , 22 b , 22 c , 22 d , 22 e , 22 f may have a separate power control if a multi-channel RF power source is used (not shown, but known to those of ordinary skill in the art). In this way, the thermal field and heating of tissue can be varied and further controlled.
[0054] In the foregoing arrangement, during operation of the device 34 , ultrasound energy is emitted by the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f in a radially outward direction, thereby approximating the directional effect of three cylindrical transducers when the device 34 is in an undeployed state (as shown in FIGS. 3 and 4). Furthermore, when the device 34 is in its deployed state, the carrier bars 60 , 62 and also, therefore, the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f mounted thereon, form a “V” shape (see FIGS. 5 and 6). When the device 34 is in its deployed state, the ultrasound energy is emitted by the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f in the direction shown by the arrows in FIG. 6 (which shows the device 34 in use, in its deployed state, after insertion into the vagina 100 and uterus 98 of a female patient). The method of operating the device 34 in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter.
[0055] With reference to FIGS. 5, 6 and 7 , in particular, the proximal ends of the first and second carrier bars 60 , 62 each have an extended tongue 64 , 66 , respectively, by which each of the first and second carrier bars 60 , 62 is pivotably attached to the distal end of a corresponding actuator rod 68 , 70 , respectively. More specifically, as seen most clearly in FIGS. 7, 8 and 9 , the extended tongue 64 of the first carrier bar 60 includes a first pivot hole 72 that is proximate to the first carrier bar 60 and a second pivot hole 74 that is remote from the first carrier bar 60 (in other words, proximate to the end of the extended tongue 64 ). The extended tongue 66 of the second carrier bar 62 includes a first pivot hole 76 that is proximate to the second carrier bar 62 and second pivot hole 78 that is remote from the second carrier bar 62 (in other words, proximate to the end of the extended tongue 66 ).
[0056] In addition, each of the actuator rods 68 , 70 has a ninety-degree bend proximate its distal end, which forms a pivot hook 80 , 82 on each actuator rod 68 , 70 , respectively. The pivot hooks 80 , 82 of the actuator rods 68 , 70 are each sized and shaped to fit into the first pivot hole 72 , 76 of a corresponding one of the first and second carrier bars 60 , 62 , respectively (see FIGS. 7, 8 and 9 ). The hollow sleeve 56 has two pivot pins 84 , 86 at its distal end that are each sized and shaped to be received through the second pivot hole 74 , 78 of a corresponding one of the first and second carrier bars 60 , 62 , respectively (see FIGS. 7, 8 and 9 ).
[0057] With continued reference to FIGS. 7, 8 and 9 , it is noted that the positions of each of the pivot pins 84 , 86 of the hollow sleeve 56 are stationary relative to the hollow sleeve 56 and relative to the first and second carrier bars 60 , 62 . Thus, when the pivot pins 84 , 86 of the hollow sleeve 56 are received within the second pivot holes 74 , 78 of the first and second carrier bars 60 , 62 , respectively, they form the pivot point of each of the first and second carrier bars 60 , 62 thereby allowing the first and second carrier bars 60 , 62 , with the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f mounted thereon, to form the abovementioned “V” shape. As seen most clearly in FIGS. 8 and 9, when the pivot hooks 80 , 82 of the actuator rods 68 , 70 are received within the first pivot holes 72 , 76 of the first and second carrier bars 60 , 62 , respectively, the distal ends of the actuator rods 68 , 70 extend together in between the pivot pins 84 , 86 of the hollow sleeve 56 . The purpose of the foregoing arrangement of pivot holes 72 , 74 , 76 , 78 , pivot hooks 80 , 82 and pivot pins 84 , 86 will become apparent hereinafter during discussion of the operation of the device 34 .
[0058] With reference now specifically to FIGS. 3, 4 and 7 , the actuator rods 68 , 70 are slidingly received in the through passages 58 , 54 of the hollow sleeve 56 and the hollow shaft 52 , respectively, and extend together from the first and second carrier bars 60 , 62 , through the through passages 58 , 54 , and out of the proximal end of the hollow shaft 52 . The proximal end of each actuator rod 68 , 70 is affixed to the distal end 88 of the pivotable arm 40 . More particularly, the proximal end of each actuator rod 68 , 70 is inserted through one of a pair of holes 90 , 92 provided in the distal end 88 of the pivotable arm 40 (see FIG. 7) and the proximal end of each actuator rod 68 , 70 includes an enlarged stop 94 , 96 , respectively, thereon for retaining the proximal ends of the actuator rods 68 , 70 through the holes 90 , 92 .
[0059] With reference to the overall size and shape of the device 34 , it is noted that while the device 34 of the present invention may be adapted for ablation of tissue within cavities or lumens other than the uterus, the embodiments disclosed herein are intended for use in performing endometrial ablation and, therefore, they are sized and shaped to be inserted and operated within the uterus of a patient. More particularly, the sum of the lengths of the hollow shaft 52 and hollow sleeve 56 should be between about 15 and 50 centimeters (cm), preferably about 25 cm. Regarding the individual lengths of these components, the length of the hollow shaft 52 should be from about 5 to 15 cm, preferably about 10 cm, and the length of the hollow sleeve 56 should be from about 10 to 35 cm, preferably 15 cm. Moreover, the outer diameters of the hollow shaft 52 and the hollow sleeve 56 should be substantially the same as one another and, more specifically, from approximately 5 to 10 millimeters (mm), preferably about 5 mm. The diameter of the through passages 54 , 58 of the hollow shaft 52 and the hollow sleeve 56 , respectively, should be large enough to slidingly receive therethrough both actuator rods 68 , 70 and all of the wires (not shown) attached to the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f , more particularly, from about 3 mm to 8 mm, preferably about 3.5 mm. In addition, the lengths of the first and second carrier bars 60 , 62 should be the same as one another and be between about 3 and 6 cm, preferably about 4 cm.
[0060] With regard to the size of the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f , it is noted that although they are shown in FIGS. 3 - 9 as being of the same size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the members of each pair of hemi-cylindrical transducers (for example, 22 a - 22 d , 22 b - 22 e , 22 c - 22 f in FIG. 3) should be the same size as each other. In the present embodiment of the device 34 , each hemi-cylindrical transducer 22 a , 22 b , 22 c , 22 d , 22 e , 22 f is between about 1 and 3 cm long, preferably about 1.5 cm long. In addition, each hemi-cylindrical transducer 22 a , 22 b , 22 c , 22 d , 22 e , 22 f is about 5 to 10 millimeters (mm) wide at its greater width, such that the pairs of hemi-cylindrical transducers 22 a - 22 d , 22 b - 22 e , 22 c - 22 f approximate the shape of three cylindrical transducers having an overall diameter of about 5 to 10 mm, preferably about 5 mm.
[0061] The method of using the device 34 to perform endometrial ablation will now be described. Initially, it is noted that the device 34 of the present invention may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid. The fluid is required to provide a means for the ultrasound energy emitted from the ultrasound transducers to travel to, and be absorbed by, the endometrial tissues to be treated. For purposes of the following discussion, the uterus will be prepared for surgery and filled with a suitable fluid, such as saline, in a manner that is well-known to those of ordinary skill in the art and consistent with currently accepted medical/surgical standards.
[0062] With reference now to FIG. 6, after the uterus has been prepared and filled with fluid, as described above, the device 34 in its undeployed state (see FIGS. 3 and 4) is inserted into the uterus 98 of a patient. More particularly, the device 34 is held by the finger grips 46 , 48 of the handle 36 by the surgeon and the first and second carrier bars 60 , 62 (with the undeployed hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f mounted thereon) and at least a portion of the hollow sleeve 56 are inserted through the vagina 100 and into the uterus 98 . The hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f are positioned approximately centrally within the uterus 98 , or at an otherwise appropriate position within the uterus as clinically determined by the surgeon. With reference now to FIG. 5, the device 34 is then deployed by squeezing the fixed and pivotable arms 38 , 40 together such that the pivotable arm 40 moves toward the fixed arm 38 as far as the stop post 50 , which causes the distal end 88 of the pivotable arm 40 to move away from the fixed arm 38 and the hollow shaft 52 in the direction indicated by the arrow A in FIG. 5. When the distal end 88 of the pivotable arm 40 moves away from the fixed arm 38 , the actuator rods 68 , 70 are pulled through the through passages 54 , 58 and the pivot hooks 80 , 82 at the distal ends of the actuator rods 68 , 70 are moved toward the hollow sleeve 56 in the direction indicated by the arrow B in FIGS. 5, 8 and 9 , which, in turn, causes the first and second carrier bars 60 , 62 to move away from one another, as indicated by the arrows C in FIGS. 5 and 9, into a deployed “V” shape. The RF power source (not shown) is then turned on, which causes RF power to be delivered to the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f which causes them to emit ultrasound energy, as shown by the arrows in FIG. 6, which travels to the endometrial tissue where it is absorbed, resulting in heating and ablation of the tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes.
[0063] As shown in FIG. 6, the lateral walls 102 , 104 of the uterus 98 and also, therefore, a portion of the endometrium 106 , are sloped. When the device 34 is in its deployed state, the outer surfaces 24 a , 24 b , 24 c , 24 d , 24 e , 24 f of the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f are substantially aligned with the sloping portion of the endometrium 106 such that the ultrasound energy emitted by the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f will contact the sloping portion of the endometrium 106 from a direction that is nearly perpendicular thereto, which maximizes the amount of heat energy that will be received by the endometrial tissue at this location. During in situ operation of the device 34 , the device 34 can be moved, for example back and forth or tilted, such that the carrier bars 60 , 62 and the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f mounted thereon are also so moved within the uterus 98 of the patient. Such movement will direct at least a portion of the ultrasound energy from the hemi-cylindrical transducers 22 a , 22 b , 22 c , 22 d , 22 e , 22 f upward to heat and ablate the upper endometrial tissue.
[0064] With reference now to FIGS. 10 - 16 C, a second embodiment of the device 108 in accordance with the present invention is shown. More particularly, FIGS. 10 and 11 show the device 108 in an undeployed state in a perspective view and a top plan view, respectively. FIG. 12 shows a perspective view of the device 108 in a deployed state. The device 108 includes a handle 110 having a fixed arm 112 and a pivotable arm 114 . The pivotable arm 114 is pivotably attached to the fixed arm 112 such that the handle 110 provides means for manual manipulation and operation of the device 108 , as will be described in further detail hereinafter. As seen in FIG. 14, the fixed and pivotable arms 112 , 114 each include connecting means, such as connecting ears 116 , 118 proximate to their distal ends, that cooperate in a manner known in the art to facilitate connecting the pivotable arm 114 to the fixed arm 112 in a pivotable manner. The fixed and pivotable arms 112 , 114 of the first embodiment also each include a finger grip 120 , 122 sized and shaped to receive the fingers of the surgeon therethrough for facilitating manual manipulation and operation of the device 108 . The fixed arm 112 also includes a stop post 124 to prevent the pivotable arm 114 from moving too closely toward the fixed arm 112 , thereby controlling the degree of deployment of the device 108 , as explained in further detail hereinafter.
[0065] With further reference to FIGS. 10, 11, 12 and 14 , the handle 110 also has a hollow shaft 126 that extends from the distal end of the fixed arm 112 . The hollow shaft 126 has a through passage 128 and may be formed integrally with the fixed arm 112 or it may be formed as a separate component and attached to the fixed arm 112 by conventional means, such as welding or gluing. A hollow sleeve 130 also having a through passage 132 is connected to, and extends from, the distal end of the hollow shaft 126 . The hollow sleeve 130 is sized and shaped to conform to the size and shape of the hollow shaft 126 such that their outer diameters are approximately equal and their through passages 128 , 132 , respectively, align with one another.
[0066] The device 108 also includes a cylindrical transducer 10 a positioned proximate to the distal end of the hollow sleeve 130 , as well as two incomplete cylindrical transducers 10 b , 10 c mounted upon a carrier 134 that is positioned proximate to the cylindrical transducer 10 a . Furthermore, the carrier 134 is pivotably attached, at a location intermediate its ends, to the distal end of a stationary bar 136 that has a hole 138 therethrough for such pivotable attachment (see FIGS. 14 and 15). The proximal end of the stationary bar 136 is attached to the distal end of the hollow sleeve 130 and the stationary bar 136 extends out of the hollow sleeve 130 and completely through the interior of the cylindrical transducer 10 a (see FIGS. 15 and 16A- 16 C).
[0067] With reference to FIGS. 12, 13 and 14 , in particular, the device 108 also includes an actuator rod 140 with a hole 142 at its distal end and an enlarged plug 144 at its proximate end. The actuator rod 140 is slidingly received within the through passages 132 , 128 of the hollow sleeve 130 and the hollow shaft 126 and is pivotably attached at its distal end to the carrier 134 , at a position that is proximate to the position at which the stationary bar 136 is attached to the carrier 134 (see FIGS. 15 and 16A- 16 C). Furthermore, the enlarged plug 144 of the actuator rod 140 is received within a recess 146 provided in the distal end 148 of the pivotable arm 114 of the handle 110 .
[0068] It is noted that, although not specifically shown in the figures, the cylindrical transducer 10 a and the incomplete cylindrical transducers 10 b , 10 c each have a pair of electrically conductive wires (not shown), preferably as a coaxial cable (not shown), that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the cylindrical transducer 10 . To protect the wires and minimize interference with the manipulation and operation of the device 108 by the surgeon, the aforesaid wires (not shown) can be attached to the cylindrical transducer 10 a and the incomplete cylindrical transducers 10 b , 10 c and extended through the through passages 128 , 132 of the hollow shaft 126 and hollow sleeve 130 , to the RF power source (not shown).
[0069] In the foregoing arrangement, during operation of the device 108 , when RF power is supplied to the transducers 10 a , 10 b , 10 c , ultrasound energy is emitted by the cylindrical transducer 10 a in a radially outward direction, as discussed hereinabove in connection with the typical cylindrical transducer 10 . Furthermore, when the device 108 is in its deployed state, the carrier 134 and also, therefore, the incomplete cylindrical transducers 10 b , 10 c mounted thereon, are oriented perpendicularly to the cylindrical transducer 10 a (see FIGS. 12 and 15) and ultrasound energy is emitted by the incomplete cylindrical transducers 10 b , 10 c in the direction shown by the arrows in FIG. 13 (which shows the device 108 in use, in its deployed state, after insertion into the vagina 100 ′ and uterus 98 ′ of a female patient). The method of operating the device 108 in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter.
[0070] With reference now to FIGS. 15 and 16A- 16 C, it is noted that the position of the stationary bar 136 which extends from the hollow sleeve 130 is stationary relative to the hollow sleeve 130 and relative to the cylindrical transducer 10 a . Thus, the connection between the carrier 134 and the distal end of the stationary bar 136 forms the pivot point of the carrier 134 . As shown in FIGS. 16 A- 16 C, the carrier 134 , with the incomplete cylindrical transducers 10 b , 10 c mounted thereon, is pivotable between an undeployed position (shown in FIGS. 10, 11 and 16 A), wherein the incomplete cylindrical transducers 10 b , 10 c align longitudinally with the cylindrical transducer 10 a and the hollow sleeve 130 , and a deployed position (shown in FIGS. 12 16 C), wherein the incomplete cylindrical transducers 10 b , 10 c are aligned perpendicularly to the cylindrical transducer 10 a and the hollow sleeve 130 . More particularly, when the fixed and pivotable arms 112 , 114 of the handle 110 are squeezed together, the pivotable arm 114 moves toward the fixed arm 112 as far as the stop post 124 which causes the distal end 148 of the pivotable arm 114 to move away from the fixed arm 112 and the hollow shaft 126 , in the direction indicated by the arrow D in FIG. 12. When the distal end 148 of the pivotable arm 114 moves away from the fixed arm 112 , the actuator rod 140 is pulled through the through passages 128 , 132 in the direction indicated by the arrow E in FIG. 12 and, as shown in the sequential cut away views of FIGS. 16 A- 16 C, the actuator rod 140 pulls the carrier 134 from its undeployed position (FIG. 16A) to its deployed position (FIG. 16C), which results in the repositioning of the incomplete cylindrical transducers 10 b , 10 c such that they are oriented perpendicularly to the cylindrical transducer 10 a.
[0071] With reference to the overall size and shape of the device 108 , the sum of the lengths of the hollow shaft 126 and hollow sleeve 130 should be between about 15 and 20 cm, preferably about 25 cm. Regarding the individual lengths of these components, the length of the hollow shaft 126 should be from about 5 to 15 cm, preferably about 10 cm, and the length of the hollow sleeve 130 should be from about 10 to 35 cm, preferably 15 cm. Moreover, the outer diameters of the hollow shaft 126 and the hollow sleeve 130 should be substantially the same as one another and, more specifically, from approximately 5 to 10 mm, preferably about 5 mm. The diameter of the through passages 128 , 132 of the hollow shaft 126 and the hollow sleeve 130 , respectively, should be large enough to slidingly receive therethrough the actuator rod 140 (without interfering with the stationary bar 136 ) and all of the wires (not shown) attached to the cylindrical transducer 10 a and the incomplete cylindrical transducers 10 b , 10 c . More particularly, the diameter of the through passages 128 , 132 should be from about 3 mm to 15 mm, preferably about 5 mm in diameter. In addition, the length of the carrier 134 should be between about 2 and 3 cm, preferably about 3 cm.
[0072] With regard to the size of the cylindrical transducer 10 a and the incomplete cylindrical transducers 10 b , 10 c , it is noted that, although they are shown in FIGS. 3 - 9 as being of the same general size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the two transducers 10 b , 10 c that are mounted onto the carrier 134 be of similar size and shape to one another. In the present embodiment of the device 108 , each of the transducers 10 a , 10 b , 10 c is between about 1 and 3 cm long, preferably about 1.5 cm long and about 5 to 10 in diameter, preferably about 5 mm in diameter.
[0073] The method of operating the device 108 of the second embodiment to perform endometrial ablation will now be described. Initially, it is noted that, like the device 34 of the first embodiment discussed hereinabove, the device 108 of the second embodiment may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid.
[0074] With reference now to FIG. 13, after the uterus 98 ′ has been prepared and filled with fluid, as described hereinabove, the device 108 in its undeployed state (see FIGS. 10 and 11) is inserted into the uterus 98 ′ of a patient. More particularly, the device 108 is held by the finger grips 120 , 122 of the handle 110 by the surgeon and the carrier 134 (with the cylindrical transducer 10 a and undeployed incomplete cylindrical transducers 10 b , 10 c mounted thereon) and at least a portion of the hollow sleeve 130 are inserted through the vagina 100 ′ and into the uterus 98 ′. The transducers 10 a , 10 b , 10 c are positioned approximately centrally within the uterus 98 ′, or at an otherwise appropriate position within the uterus as clinically determined by the surgeon. The device 108 is then deployed, as described above in connection with FIGS. 15 and 16A- 16 C, by squeezing the fixed and pivotable arms 112 , 114 together such that the carrier 134 is moved to its deployed position and the incomplete transducers 10 b , 10 c are reoriented to be perpendicular to the cylindrical transducer 10 a and hollow sleeve 130 . The RF power source (not shown) is then turned on, which causes RF power to be delivered to the transducers 10 a , 10 b , 10 c , which causes them to emit ultrasound energy, as shown by the arrows in FIG. 13, that travels to the endometrium 106 ′ where it is absorbed, resulting in heating and ablation of the endometrial tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the transducers 10 a , 10 b , 10 c . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes.
[0075] As can be seen from viewing FIG. 13, the ultrasound energy emitted by the transducers 10 a , 10 b , 10 c when the device 108 is in its deployed state achieves wider coverage of the endometrium 106 ′ than the ultrasound energy that would be emitted from a device having only longitudinally aligned transducers (such as, for example, the arrangement of the transducers 10 a , 10 b , 10 c when the device 108 is in its undeployed state as in FIG. 10). More particularly, in its deployed state, the device 108 delivers ultrasound energy directly to the top wall 150 ′ of the uterus 98 ′, which would otherwise be nearly entirely neglected by existing devices having only longitudinally aligned transducers. As with the device 34 of the first embodiment, the device 108 of the second embodiment can be moved, for example back and forth or tilted, during in situ use such that the transducers 10 a , 10 b , 10 c are also so moved within the uterus 98 of the patient. Such movement will allow the surgeon to have greater directional control of at least a portion of the ultrasound energy that is emitted from the transducers 10 a , 10 b , 10 c toward the endometrial tissue.
[0076] With reference now to FIGS. 17 - 23 , a third embodiment of the device 152 in accordance with the present invention is shown. More particularly, FIGS. 17 and 18 show the device 152 in an undeployed and extended state in a perspective view and a top plan view, respectively. FIG. 19 shows a perspective view of the device 152 in a deployed and extended state, while FIG. 20 shows a perspective view of the device 152 in a fully deployed and retracted state.
[0077] With reference in particular to FIGS. 17 - 20 and 22 , the device 152 includes a handle 154 with lateral walls 156 , 158 and a bottom portion 160 that form a cavity 162 therebetween. The handle 154 includes a first pair of aligned holes 164 (only one of which is visible) through the lateral walls 156 , 158 and a second pair of aligned holes 166 (only one of which is visible) through the lateral walls, for a purpose to be explained hereinafter. The handle 154 also includes a deploying lever 168 and a retraction trigger 170 that are sized and shaped to fit at least partly within the cavity 162 , as described hereinafter.
[0078] More particularly, with reference to FIG. 22, the retraction trigger 170 has a planar body 172 with a finger pad 174 and a post 176 extending therefrom and an elongate slot 178 . When the retraction trigger 170 is positioned within the cavity 162 of the handle 154 , a pivot hole 180 on the planar body 172 aligns with the first pair of holes 164 (only one of which is visible) and a pin 182 is inserted therethrough, thereby pivotably mounting the retraction trigger 170 within the cavity 162 . In addition, the elongate slot 178 on the planar body 172 aligns with the second pair of aligned holes 166 (only one of which is visible) and a bolt 167 is inserted therethrough, whereby the retraction trigger 170 is pivotable between a predetermined extended position (shown in FIGS. 17 and 19) and a predetermined retracted position (see FIG. 20). Furthermore, the post 176 and finger pad 174 extend out of the cavity 162 when the retraction trigger 170 is pivotably mounted within the cavity 160 , for purposes which will become apparent hereinafter.
[0079] With reference again to FIG. 22, the deploying lever 168 has a pair of leg extensions 184 , 186 with holes 188 , 190 for receiving therethrough a pin 192 which extends from the retraction trigger 170 , whereby the deploying lever 168 is pivotably mounted onto the retraction trigger 170 . As shown in FIGS. 17 and 19- 21 , the deploying lever 168 also has a thumb peg 194 which extends out of the cavity 162 and with which the deploying lever 168 is movable between an undeployed position (see FIG. 17) and a deployed position (see FIG. 19), as will be described hereinafter.
[0080] With reference to FIGS. 17 - 20 and 22 , the handle 154 also includes a hollow shaft 196 extending therefrom and having a through passage 198 . The device 152 further includes a hollow sleeve 200 that is connected to and extends from the hollow shaft 196 of the handle 154 . The hollow sleeve 200 has a through passage 202 (see FIG. 22 only), as well as a proximal portion 204 and a distal portion 206 that is narrower than the proximal portion 204 . An actuator sleeve 208 is slideably received within the through passages 198 , 202 of the hollow shaft 196 and the hollow sleeve 200 . The actuator sleeve 208 has a fork extension 210 at its proximal end that is sized and shaped to be moveably attached to the thumb peg 194 of the deploying lever 168 (see FIGS. 17, 19 and 20 ). The actuator sleeve 208 also has a pair of prongs 212 , 214 , each with a hole 216 , 218 , respectively, at its distal end, for a purpose which will be explained hereinafter.
[0081] With continued reference to FIGS. 17 - 20 and 22 , the actuator sleeve 208 has a bore 220 (shown in phantom in FIG. 22 only) therethrough within which a retraction rod 222 is slideably received. The proximal end of the retraction rod 222 is provided with a connector 224 having a hole 226 which is sized and shaped to receive the post 176 of the retraction trigger 170 therethrough, in a moveable manner (see FIGS. 17 - 20 ). The retraction rod 222 also has, at its distal end, a tab 228 with a hole 230 and a pin 232 , for a purpose which will be explained hereinafter.
[0082] The device 152 also includes a cylindrical transducer 10 d that is securely received about the narrow distal portion 206 of the hollow sleeve 200 . In addition, a first hemi-cylindrical transducer 22 g is mounted onto a first carrier bar 234 . The first carrier bar 234 has a tongue 236 at one end with a first hole 238 proximate to the first carrier bar 234 and a second hole 240 located remotely from the first carrier bar 234 . The second hole 240 of the first carrier bar 234 is aligned with the hole 230 on the tab 228 at the distal end of the retraction rod 222 and a plug 242 is inserted through both holes 230 , 238 , thereby moveably attaching the first carrier bar 234 to the retraction rod 222 (see dotted lines in FIG. 22 and see FIG. 23). The first carrier bar 234 is moveably connected to the distal end of the actuator sleeve 208 by a first connector rod 244 having two hooked ends 246 , 248 , as follows. As indicated by the dotted lines provided in FIG. 22 and shown in FIG. 23, one hooked end 246 of the first connector rod 244 is pivotably inserted into the hole 216 of one of the prongs 212 at the distal end of the actuator sleeve 208 and the other hooked end 248 is pivotably inserted into the first hole 238 on the tongue 236 of the first carrier bar 234 .
[0083] The device 152 also includes a second hemi-cylindrical transducer 22 g mounted onto a second carrier bar 250 . The second bar carrier bar 250 has a tongue 252 at one end with a first hole 254 proximate to the second carrier bar 250 and a second hole 256 located remotely from the second carrier bar 250 . The pin 232 on the tab 228 at the distal end of the retraction rod 222 is moveably received within the second hole 256 of the second carrier bar 250 , thereby moveably attaching the second carrier bar 250 to the retraction rod 222 (see dotted lines in FIG. 22 and see FIG. 23). The second carrier bar 250 is moveably connected to the distal end of the actuator sleeve 208 by a second connector rod 258 having two hooked ends 260 , 262 , as follows. As indicated by the dotted lines provided in FIG. 22 and shown in FIG. 23, one hooked end 260 of the second connector rod 258 is pivotably inserted into the hole 218 of the other prong 214 at the distal end of the actuator sleeve 208 and the other hooked end 262 of the second connector rod 258 is pivotably inserted into the first hole 254 on the tongue 252 of the second carrier bar 250 .
[0084] It is noted that, although not specifically shown in the figures, the cylindrical transducer 10 d and the hemi-cylindrical transducers 22 g , 22 h each have a pair of electrically conductive wires (not shown), preferably as a coaxial cable (not shown), that are connected to their inner and outer surfaces, as well as to one or more RF power sources (not shown), as described hereinabove in connection with the construction and operation of the cylindrical and hemi-cylindrical transducers 10 , 22 . To protect the wires and minimize interference with the manipulation and operation of the device 152 by the surgeon, the aforesaid wires (not shown) can be attached to the cylindrical transducer 10 d and the hemi-cylindrical transducers 22 g , 22 h and extended through the through passages 198 , 202 of the hollow shaft 196 and hollow sleeve 200 (or through the bore 220 of the actuator sleeve 208 ), to the RF power source (not shown).
[0085] In the foregoing arrangement, during operation of the device 152 , when RF power is supplied to the transducers 10 d , 22 g , 22 h , ultrasound energy is emitted by the cylindrical transducer 10 d in a radially outward direction, as discussed hereinabove in connection with the typical cylindrical transducer 10 . Furthermore, when the device 152 is in its deployed state (see FIGS. 19 and 20), the carrier bars 234 , 250 and also, therefore, the hemi-cylindrical transducers 22 g , 22 h mounted thereon, are oriented perpendicularly to the cylindrical transducer 10 d and ultrasound energy is emitted by the hemi-cylindrical transducers 22 g , 22 h in the direction shown by the arrows in FIG. 21 (which shows the device 152 in use, in its deployed state, after insertion into the vagina 100 ″ and uterus 98 ″ of a female patient). The method of operating the device 152 in accordance with the present invention, as well as the advantages achieved thereby, will be described in further detail hereinafter.
[0086] With reference now to FIGS. 17, 19 and 20 , operation of the device to move the hemi-cylindrical transducers 22 g , 22 h from their undeployed positions to their deployed and retracted positions will now be explained. It is noted that the cylindrical transducer 10 d is not deployable and, therefore, remains in a fixed position with respect to the hollow sleeve 200 . With reference in particular to FIG. 17, the device 152 is shown with the hemi-cylindrical transducers 22 g , 22 h in their undeployed and extended positions and, when they are in such positions, the retraction lever 170 of the handle 154 is positioned such that the finger pad 174 extends fully out of the cavity 162 and the post 176 is at a position nearest to the hollow shaft 196 . In addition, the deploying lever 168 is pivoted away from the retraction lever 170 such that the thumb peg 194 is pivoted to a position away from the post 176 .
[0087] When the thumb peg 194 is pressed (for example, by a surgeon's thumb) toward the post 176 and hollow shaft 196 , in the direction indicated by the arrow F in FIG. 19, the actuator sleeve 208 is moved slideably through the through passages 198 , 202 of the hollow shaft 196 and the hollow sleeve 200 , respectively, in the direction indicated by the arrow G in FIG. 19. The distal end of the actuator sleeve 208 , in turn, pushes the first and second connector rods 244 , 258 also in the direction of the arrow G in FIG. 19. The retractor rod 222 remains stationary and, as a result of the movement of the first and second connector rods 244 , 258 , the first and second carrier bars 234 , 250 (with the hemi-cylindrical transducers 22 g , 22 h mounted thereon) are pivotably moved (in the directions indicated by the arrows H in FIGS. 17 and 19) from their undeployed positions (see FIG. 17) to their deployed positions (see FIGS. 19 and 20), which is perpendicular to the cylindrical transducer 10 d and the hollow sleeve 200 .
[0088] As shown in FIG. 19, when the first and second carrier bars 234 , 250 (with the hemi-cylindrical transducers 22 g , 22 h mounted thereon) are pivotably moved to their deployed positions, the distance between the hemi-cylindrical transducers 22 g , 22 h and the cylindrical transducer 10 d become significant. Thus, it is preferable to move, or retract, the hemi-cylindrical transducers 22 g , 22 h closer to the cylindrical transducer 10 d and hollow sleeve 200 (i.e., in the direction indicated by the arrow J in FIG. 20).
[0089] Thus, when the finger pad 174 is pushed into the cavity 162 of the handle 154 (in the direction indicated by the arrow K in FIG. 20), the entire retraction lever 170 is pivoted backward, which moves the post 176 and the thumb peg 194 (with the actuator sleeve 208 connected thereto) backward away from the hollow shaft 196 (in the direction indicated bythe arrow L in FIG. 20). The actuator sleeve 208 is moved slideably backward though the through passages 198 , 202 of the hollow shaft 196 and the hollow sleeve 200 , respectively, in the direction indicated by the arrow J in FIG. 20). Similarly and simultaneously, the retraction rod 222 is also slideably moved in the direction indicated by the arrow J in FIG. 20, through the bore 220 of the actuator sleeve 208 , which pulls, or retracts, the first and second carrier bars 234 , 250 (with the hemi-cylindrical transducers 22 g , 22 h mounted thereon), in their deployed positions, backward toward the cylindrical transducer 10 d and hollow sleeve 200 , in the direction of the arrow J. After the foregoing procedure, the device 154 and hemi-cylindrical transducers 22 g , 22 h are in their deployed positions, which are shown in FIG. 20.
[0090] With reference to the overall size and shape of the device 152 , the sum of the lengths of the hollow shaft 196 and hollow sleeve 200 should be between about 10 and 30 cm, preferably about 20 cm. Regarding the individual lengths of these components, the length of the hollow shaft 196 should be from about 5 to 10 cm, preferably about 10 cm, and the length of the hollow sleeve 200 should be from about 5 to 15 cm, preferably 10 cm. Moreover, the outer diameters of the hollow shaft 196 and the proximal portion 204 of the hollow sleeve 200 should be substantially the same as one another and, more specifically, from approximately 3 to 10 mm, preferably about 5 mm. The outer diameter of the narrow distal portion 206 of the hollow sleeve 200 should correspond to the inner diameter of the cylindrical transducer 10 d such that the cylindrical transducer 10 d is snugly received thereon. Furthermore, the length of the narrow distal portion 206 of the hollow sleeve 200 should be the same or slightly (i.e., about 2 to 5 mm) longer than the length of the cylindrical transducer 10 d , which is specified hereinafter.
[0091] The diameter of the through passages 198 , 202 of the hollow shaft 196 and the hollow sleeve 200 , respectively, should be large enough to slidingly receive therethrough the actuator sleeve 208 all of the wires (not shown) attached to the cylindrical transducer 10 a and the incomplete cylindrical transducers 10 b , 10 c , more particularly, from about 3 mm to 10 mm, preferably about 4 mm. In addition, the length of the first and second carrier bars 234 , 250 should, but do not have to be, approximately the same as one another, for example, between about 10 and 3 mm long each, preferably about 15 mm long each.
[0092] With regard to the size of the cylindrical transducer 10 d and the hemi-cylindrical transducers 22 g , 22 h , it is noted that, although they are shown in FIGS. 17 - 22 as being of the same general size as one another, they do not have to be the same size and, in fact, may be differently sized. It is preferable, however, that the two hemi-cylindrical transducers 22 g , 22 h be of similar size and shape to one another. In the present embodiment of the device 152 , each of the transducers 10 d , 22 g , 22 h is between about 1 and 3 cm long, preferably about 1.5 cm long. Moreover, a suitable diameter for the cylindrical transducer 10 d is about 5 to 10 mm in diameter, preferably about 5 mm in diameter. In addition, each hemi-cylindrical transducer 22 g , 22 h is about 5 to 10 millimeters (mm) wide at its greater width such that, when the hemi-cylindrical transducers 22 g , 22 h are in the undeployed state, they approximate the shape of a cylindrical transducer having an overall diameter of about 5 to 10 mm, preferably about 5 mm.
[0093] The method of operating the device 152 of the second embodiment to perform endometrial ablation will now be described. Initially, it is noted that, like the devices 34 , 108 of the first and second embodiments discussed hereinabove, the device 152 of the second embodiment may be used in conjunction with a fluid-filled balloon, such as is well-known in the art for treating the endometrium, or it may be used without such a balloon and, instead the uterus should be filled with fluid.
[0094] With reference now to FIG. 21, after the uterus 98 ″ has been prepared and filled with fluid, as described hereinabove, the device 152 in its undeployed state (see FIGS. 10 and 11) is inserted into the uterus 98 ″ of a patient. More particularly, the device 152 is held by the handle 154 by the surgeon and the first and second carrier bars 234 , 250 (with the undeployed hemi-cylindrical transducers 22 g , 22 h mounted thereon), the cylindrical transducer 10 d , and at least a portion of the hollow sleeve 200 are inserted through the vagina 100 ″ and into the uterus 98 ″. The transducers 10 d , 22 g , 22 h are positioned approximately centrally within the uterus 98 ″, or at an otherwise appropriate position within the uterus 98 ″ as clinically determined by the surgeon. The hemi-cylindrical transducers 22 g , 22 h are then deployed and retracted, as described above in connection with FIGS. 17, 19 and 20 , by first pressing the thumb peg 194 in the direction indicated by the arrow F in FIG. 19 to deploy the hemi-cylindrical transducers 22 g , 22 h into a position that is perpendicular to the cylindrical transducer 10 d . Then the finger peg 174 is in the direction of the arrow K in FIG. 20 to retract the hemi-cylindrical transducers 22 g , 22 h into a position that is closer to the cylindrical transducer 10 d.
[0095] The RF power source (not shown) is then turned on, which causes RF power to be delivered to the transducers 10 d , 22 g , 22 h , which causes them to emit ultrasound energy, as shown by the arrows in FIG. 21, that travels to the endometrium 106 ″ where it is absorbed, resulting in heating and ablation of the endometrial tissue. After a period of time, which is clinically determined by the surgeon, the RF power source (not shown) is turned off, which ceases the ultrasound energy emissions from the transducers 10 d , 22 g , 22 h . Typically, the period of time between turning the RF power source on and turning it off is between about 2 and 10 minutes, but no more than about 20 minutes and preferably from about 2 to 3 minutes.
[0096] As can be seen from viewing FIG. 21, the ultrasound energy emitted by the transducers 10 a , 10 b , 10 c when the device 152 is in its deployed state achieves wider coverage of the endometrium 106 ″ than the ultrasound energy that would be emitted from a device having only longitudinally aligned transducers (such as, for example, the arrangement of the transducers 10 d , 22 g , 22 h when the device 152 is in its undeployed state as in FIG. 17). More particularly, in its deployed state, the device 154 delivers ultrasound energy directly to the top wall 150 ″ of the uterus 98 ″, which would otherwise be nearly entirely neglected by existing devices having only longitudinally aligned transducers. As with the devices 34 , 108 of the first and second embodiments, the device 152 of the third embodiment can be moved, for example back and forth or tilted, during in situ use such that the transducers 10 d , 22 g , 22 h are also so moved within the uterus 98 ″ of the patient. Such movement will allow the surgeon to have greater directional control of at least a portion of the ultrasound energy that is emitted from the transducers 10 d , 22 g , 22 h toward the endometrial tissue. The RF source may have multiple (for example, three) individual channels such that the power level supplied to each of the transducers 10 d , 22 g , 22 h can be individually controlled. The transducers 10 d , 22 g , 22 h may also be “multiplexed” such that a single RF power source is sequentially switched among the transducers 10 d , 22 g , 22 h.
[0097] It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications, including but not limited to those discussed hereinabove, without departing from the spirit and scope of the present invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.
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A device for thermal ablation therapy having emitting means for emitting ultrasound energy capable of heating tissue and moving means for moving the emitting means between an undeployed position, in which the emitting means is in a first orientation which facilitates insertion of the device, and a deployed position, in which the emitting means is in a different second orientation that is selected to efficiently deliver ultrasound energy to the tissue to be ablated. The moving means includes one or more movable carriers and the emitting means is one or more piezoelectric transducers that are securely mounted on the carriers for conjoint movement therewith. A method for thermal ablation therapy using ultrasound energy involves positioning an ultrasound device in an undeployed position proximate to tissue to be heated; moving the ultrasound device from its undeployed position to a deployed position; and activating the ultrasound device to emit ultrasound energy for a predetermined period of time.
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CROSS REFERENCE TO RELATED APPLICATIONS
Patent applications entitled “Restoration of Data Backed up on Archive Media”, “Backing up Computer Data”, Redundant Storage of Computer Data”, and “Hierarchical Performance System” filed by me concurrently herewith, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to mirroring computer data stored on a host computer storage disk.
One way to automatically provide backup of data on a computer system is by mirroring. It is known to implement mirroring on a desktop computer by having a disk driver that does all writes to two disks which thus have identical images of the stored data in the event of catastrophic failure of one disk. If one disk fails, the complete image of the data on the other disk can be accessed.
SUMMARY OF THE INVENTION
In one aspect, the invention features, in general, a computer having capabilities for backing up data to a remote archive repository. The computer includes the usual components of an interpreter (e.g., a file system or a database application that does physical to logical mapping), a host storage disk, and a host storage driver for the host storage disk. In addition the computer includes a mirror system having a disk driver interface to the interpreter and a remote procedure call interface to a remote archive repository. The mirror system sends the write requests and the data to be written from the interpreter to the host storage driver and to the remote archive repository.
In another aspect the invention features in general a computer system including a plurality of desk top computers that are connected to a network to which a remote archive repository is connected. The computers each have a mirror system as has already been described and send copies of data to be backed up to the common remote archive repository.
In another aspect the invention features in general a computer implemented method of backing up data to a remote archive repository. An interpreter on the computer maps logical user write requests to physical block level write requests. A mirror system having a disk driver interface to the interpreter and a remote procedure call interface to a remote archive repository sends the write requests and data to be written to a host storage driver for writing on a host storage disk and to the remote archive repository.
In another aspect the invention features a computer program that resides on a computer-readable medium and includes instructions causing the computer to create a mirror system as has already been described.
Certain implementations of the invention may include one or more of the following features. In certain implementations: the mirror system includes a mirror driver and an archive media system, the mirror driver providing the disk driver interface and also having an operating system device driver application programming interface to the archive media system, the archive media system being implemented in the user space of the computer and communicating with the remote archive repository; the remote archive repository includes a control program, disk storage, and a tape library.
Embodiments of the invention may have one or more of the following advantages. Mirroring is provided for a computer without the need to add hardware or backup software. The remote archive repository can be shared by a large number of computers. The approach is portable across different vendors' implementations of an operating system and different operating systems.
Other advantages and features of the invention will be apparent from the following description of a preferred embodiment thereof and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of system for mirroring of data on a plurality of computers connected to a network.
FIG. 2 is a diagram of a computer of the FIG. 1 system.
FIG. 3 is a diagram illustrating the images of stored data on a remote archive repository of the FIG. 2 computer.
FIG. 4 is a flow chart showing the steps employed by an archive media system of the FIG. 2 computer.
FIG. 5 is a flow chart showing the steps employed by a mirror driver of the FIG. 1 system.
FIG. 6 is a flow chart showing the steps employed by a central repository control program of the FIG. 1 system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown networked computer system 10 . It includes a large number of desktop or other computers 12 and remote archive repository 14 all connected over network 16 , which can be a local area or wide area network. Remote archive repository 14 includes repository control program 18 , disk storage 19 (e.g., an ICDA) and tape library 20 , though other archive media can be employed. Tape library 20 includes a plurality of tapes 36 , drives 38 to access tapes 36 , and a robot (not shown) to move tapes 36 into drives 38 .
Referring to FIG. 2, computer 12 includes user applications 22 and archive media system 24 in the user application space of the computer. As also shown in FIG. 24, computer 12 includes file system 26 (e.g., the file system present in a UNIX operating system), host storage driver 28 , and mirror driver 30 in the kernel space of the computer, and host disk 32 . Archive media system 24 is connected to communicate with remote archive repository 14 through network 16 . Mirror driver 30 and archive media system 24 together make up mirror system 34 .
File system 26 , host storage driver 28 , and host disk 32 are common components of a computer. File system 26 and host storage driver 28 are provided in the operating system of the computer, and disk 32 is the physical medium on which the data are actually stored. A “block” of data (which might be 512 or 1K bytes or larger depending on the computer and the media type) is the smallest set of data that can be accessed on the physical media (e.g., disk 32 ). File system 26 carries out a logical to physical mapping; given a file name, it accesses file tables to determine where the file is physically located and converts a file name to a set of physical blocks. The file tables, which are stored along with actual data on disk 32 , identify, for each file name, the starting block and the number of blocks in the file.
Archive media system 24 processes both read (after there is a failure of disk 32 ) and write requests (i.e., the mirroring). FIG. 4 is a flow chart showing the steps employed by archive media system 24 . Archive media system 24 uses the network identifier for its respective computer 12 to identify the mirror data being stored at remote archive repository 14 . Archive media system 24 has a remote procedure call interface for transmitting data to remote archive repository 14 . When blocks of data are sent from desktop computers 12 to remote archive repository 14 , they are tagged with information as to which computer they came from (in the preferred implementation this is inferred from the network address) and the device name and the physical block number.
Mirror driver 30 has a disk driver interface to file system 26 , and looks like a disk driver to file system 26 , but its function is to make a copy of all data being written to host storage driver 28 and to transfer that copy to archive media system 24 for updating a mirror image in remote archive repository 14 . Mirror driver 30 has an operating system device driver application programming interface to archive media system 24 . In a Unix operating system environment, archive media system 24 and mirror driver 30 can communicate via IOCTL messages, which have the following format: (operation, address of a given buffer, optional arguments). FIG. 5 is a flow chart showing the steps employed by mirror driver 30 . When first started up, archive media system 24 makes an IOCTL call to mirror driver 30 ; there would initially not be a return of the call, because there would not be any copied data to process. When there are copied data to process, the IOCTL call is returned by mirror driver 30 , and archive media system 24 looks at the return values of the IOCTL, which specify whether the operation is a read or write, the starting block number, and the number of blocks. If the operation is a write, the return includes the data being written, which are then transmitted to remote archive repository 14 (or other archive media). Archive media system 24 then sends another IOCTL call and waits for mirror driver 30 to return the IOCTL return when there are more copied data for processing.
Referring to FIGS. 2 and 3, on remote archive repository 14 , a file corresponding to an image 40 A- 40 J in FIG. 3 is kept on disk storage 19 for each host disk 32 of each desktop computer 12 . The blocks are placed at the correct position inside the file. This file represents a real-time copy of the actual disk on the desktop computer. Alternatively, a full copy of the disk could be maintained on tape library 20 , with incremental changes being kept on disk storage 19 . The data backed up in the physical level mirror copies of host disks 32 include the file tables used by file system 26 to correlate file names with physical blocks. FIG. 7 is a flow chart showing the steps employed by central repository control program 18 to store backed up information and access storage disk 19 , tapes 36 and drives 38 .
In operation, read operations from disk 32 are handled in the normal course without copying of information. When writing, file system 26 communicates with mirror driver 30 to write the data beginning at a starting block and continuing for a number of blocks as if mirror driver 30 were a conventional host storage driver. Mirror driver 30 then passes the information on the starting block and number of blocks to host storage driver 28 and to archive media system 24 . The actual data are copied by mirror driver 30 and passed to both host storage driver 28 , for storage on disk 32 , and to archive media system 24 , for storage at remote archive repository 14 .
Remote archive repository 14 treats the copied data as a regular file. Special requests can be made to the mirror driver 30 and passed on to remote archive repository 14 to freeze the current image for that personal computer 12 ; remote archive repository 14 would freeze the image and start a new mirrored image for subsequent changes. The user could then access the frozen image when desired for recovery or back up at any time to tape library 20 .
When host disk 32 has failed and a new disk has been installed, a recovery process on desktop computer 12 can be accessed to ask for the physical blocks to be sent back. Archive media system 24 also has a user interface to identify the data set to be restored and to cause information that was stored on disk 32 to be restored from remote archive repository 14 .
In system 10 a large number of computers 12 share remote archive repository 14 for mirroring, avoiding the need for additional hardware at the individual computers. The use of mirror driver 30 and AMS 24 makes the approach portable across different vendors' implementations of an operating system and also across different operating systems.
OTHER EMBODIMENTS
Other embodiments of the invention are within the scope of the appended claims. E.g., in a computer where a user application 22 is a database server application that does logical to physical mapping on a so-called raw partition that bypasses file system 26 , mirror driver 30 would communicate directly with the database server application 22 . In this case the database server application 22 would be considered the interpreter.
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A computer including an interpreter that maps logical user write requests to physical block level write requests, a host storage driver having a disk driver interface for receiving block level write requests, a host storage disk connected to be controlled by disk control signals of the host storage driver, and a mirror system having a disk driver interface to the interpreter and a remote procedure call interface to a remote archive repository, the mirror system sending write requests and data to be written from the interpreter to the host storage driver and to the remote archive repository.
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The present patent application is a continuation-in-part of U.S. patent application Ser. No. 09/407,253 filed Sep. 28, 1999, now abandoned.
FIELD OF THE INVENTION
The present invention relates to retaining walls. More particularly, the present invention relates to internally filled retaining walls prepared from a plurality of open core, man-made block elements having a trapezoidal structure, wherein the major face of the block elements form the outer surface of the retaining wall. Even more specifically, the present invention relates to a retaining wall comprised of a series of open core retaining wall block elements that are securely arranged using an anchoring composition including a plurality of anchoring stones and a synthetic resin.
BACKGROUND OF THE INVENTION
Soil retention, protection of natural and artificial structures, and increased land use are only a few reasons which motivate the use of landscape structures. For example, soil is often preserved on a hillside by maintaining the foliage across that plane. Root systems from trees, shrubs, grass, and other naturally occurring plant life work to hold the soil in place against the forces of wind and water. However, when reliance on natural mechanisms is not possible or practical man often resorts to the use of artificial mechanisms such as retaining walls.
In constructing retaining walls many different materials may be used depending upon the given application. If a retaining wall is intended to be used to support the construction of an interstate roadway, a steel retaining wall, perhaps combined with concrete, may be appropriate. However, if the retaining wall is intended to landscape and conserve soil around a residential or commercial structure, a material may be used which compliments the architectural style of the structure such as wood timbers or concrete block.
Of all these materials, concrete block has received wide and popular acceptance for use in the construction of retaining walls and the like. Blocks used for these purposes include those disclosed by Risi et al, U.S. Pat. Nos. 4,490,075 and Des. 280,024 and Forsberg, U.S. Pat. Nos. 4,802,320 and Des. 296,007 among others. Blocks have also been patterned and weighted so that they may be used to construct a wall which will stabilize the landscape by the shear weight of the blocks. These systems are often designed to “setback” at an angle to counter the pressure of the soil behind the wall. Setback is generally considered the distance which one course of a wall extends beyond the front of the next highest course of the same wall. Given blocks of the same proportion, setback may also be regarded as the distance which the back surface of a higher course of blocks extends backwards in relation to the back surface of the lower wall courses. In vertical structures such as retaining walls, stability is dependent upon the setback between courses and the weight of the blocks.
For example, U.S. Pat. No. 2,313,363 to Schmitt discloses a retaining wall block having a tongue or lip which secures the block in place and provides a certain amount of setback from one course to the next. The thickness of the Schmitt tongue or lip at the plane of the lower surface of the block determines the setback of the blocks. However, smaller blocks have to be made with smaller tongues or flanges in order to avoid compromising the structural integrity of the wall with excessive setback. Manufacturing smaller blocks having smaller tongues using conventional techniques results in a block tongue or lip having inadequate structural integrity. Concurrently, reducing the size of the tongue or flange with prior processes may weaken and compromise this element of the block, the course, or even the entire wall.
The current design of pinless, mortarless masonry blocks generally also fails to resolve other problems such as the ability to construct walls which follow the natural contour of the landscape in a radial or serpentine pattern. Previous blocks also have failed to provide a system allowing the use of anchoring mechanisms which may be affixed to the blocks without complex pinning or strapping fixtures. Besides being complex, these pin systems often rely on only one strand or section of a support tether which, if broken, may completely compromise the structural integrity of the wall. Reliance on such complex fixtures often discourages the use of retaining wall systems by the every day homeowner. Commercial landscapers generally avoid complex retaining wall systems as the time and expense involved in constructing these systems is not supportable given the price at which landscaping services are sold. As can be seen the present state of the art of forming masonry blocks as well as the design and use of these blocks to build structure has definite shortcomings.
The applicant herein has solved some of the problems with a concrete block approach wherein the block was constructed in a trapezoidal form with parallel front and rear walls and a pair of sidewalls converging from front to rear. Unfortunately, while the blocks were quite useful in allowing a wall made therefrom to follow a serpentine pattern, the strength of the blocks was insufficient to avoid breakage during installation of numerous blocks, thus making the use of the blocks uneconomical.
SUMMARY OF THE INVENTION
The present invention is intended for use in decorative and functional walls which can be constructed as a gravity wall system, geogrid system, pyramid system, or as a combination of all of the these. In general, the retaining element disclosed in the assembly discussed herein is an improvement over the shaped block previously used by the applicant and provides greater strength per unit for the fabrication of the wall. As with the prior art system used by the Applicant, each element has a large core. In the present invention, the block elements provide maximum stability through the inclusion anchoring stone and a synthetic resin that surround a mesh grid or mat that is placed between the block elements. More specifically, two rows of block elements are separated by the mesh grid, with anchoring stones traversing the cores of the block elements. The liquid resin is thereby used to connect the mesh grid and the anchoring
stones to provide a positive connection and strength not found in competitive products without more complicated designs. The construction of the block elements increases the wall strength of the converging walls such that they are less susceptible to fracture during construction of the wall, by adding mass to the walls without significantly diminishing the core area, and the anchoring stones and resin further strengthen the completed retaining wall.
These and other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The improved retaining wall assembly formed is depicted in the appended drawings which form a portion of this disclosure and wherein:
FIG. 1 is a top plan view of the prior art block element;
FIG. 2 is a top plan view of an block element used in the improved retaining wall assembly of the present invention;
FIG. 3 is a sectional top view of the block element used in the improved retaining wall assembly of the present invention, with the view illustrating an anchoring composition filing the central core of the block element;
FIG. 4 is a perspective view of a straight retaining wall constructed with block elements of the present invention; and
FIG. 5 is a perspective view of a curved retaining wall constructed with block elements of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, block elements 11 used in the Applicant's initial prototype system are illustrated. The block elements 11 were generally trapezoidal in shape, having a face 12 measuring seventeen and five-eighths inches across, a parallel face 13 measuring thirteen and one-fourth inches and having a depth from front face to rear face of twelve inches. The height of each block element 11 was eight inches. Moreover, each block element 11 defined a central core 15 traversing the block element 11 , with the central core 15 having an internal volume of approximately one-half cubic foot. The thickness of the major face 12 was three inches, and the thickness of the minor face 13 was two and three-eighths inches. The thickness of each of the converging walls 14 was two and one-fourth inches.
These prototype elements were used in retaining walls in both residential and commercial landscaping environments. Through this research and use, it was determined that the strength of the converging walls 14 was insufficient to allow the block elements 11 to be used as anticipated. Specifically, the block elements 11 are laid one over the other in a laterally overlapping pattern such that the converging walls 14 are not supported along their entire length by the converging walls 14 of the subjacent block element 11 , but rather, cross the subjacent converging walls 14 at an included angle of about 60 degrees. It is routinely necessary to use a mallet to tap or pound one the top of the block elements 11 to properly seat the individual block elements 11 in close fitting courses. Unfortunately the crossing of the converging walls 14 of abutting block elements 11 creates stress points which are accentuated by the use of the mallet such that the converging wall 14 or subjacent converging wall 14 frequently fractures in the prototype. On several occasions, these block elements 11 had been tested under through applying compressive forces to the block elements 11 . Such testing studies indicated that these block designs provided only marginal results, and that it improvements in the block elements 11 , particularly the wall size of the block elements 11 , were necessary.
Referring now to FIGS. 2 through 5, the trapezoidal block elements 20 for forming an improved retaining wall 30 of the present invention are illustrated. The retaining wall 30 is designed to provide retention of a desired backfill material 8 , such as dirt or rocks. As with the block elements 11 of the prior design, the block elements 20 of the present invention have a major face 22 , a minor face 24 , and a pair of converging walls 26 that join the two faces 22 , 24 . Additionally, an open central core 28 or aperture traverses the block elements 20 as in prior designs. However, the improved block elements 20 are designed to alleviate the problem of weakness that occurred in the prototype block elements 11 while maintaining the high stability offered by the open core design. More specifically, the improved block elements 20 provide a means to strengthen retaining wall 30 , with the block elements 20 having converging walls 26 that do not significantly diminish the volume of the open central core 28 of the block elements 20 , and that are further reinforced by the distribution of an anchoring composition 31 in the central core 28 .
Continuing to view FIGS. 2 and 5, the block elements 20 have an isosceles trapezoidal shape and may be laid to form a corner at perpendicular walls using two adjacent block elements 20 abutting along adjacent converging faces 26 . A third block element 20 with a converging face 26 adjacent the second block element 20 further yields a semi-circular turn in the retaining wall 30 (see FIG. 5 ). Thus it may be seen that the shape of block elements 20 lends itself to excellent continuous flexibility of design of the retaining wall 30 . As a result, it is desirous to preserve the trapezoidal shape of the block elements 20 to maintain the strength of the retaining wall 30 .
In view of this determination, two alternatives were devised to provide strength of the retaining wall 30 but maintaining the trapezoidal shape. In the first alternative, each converging wall 26 is uniformly increased in thickness in the interior of the block element 20 by up to 0.30 inches. In so doing the volume of central core 28 is maintained at least 0.45 cubic feet. In the second alternative, converging walls 26 are gradually increased in thickness such that they flare inwardly from the minor wall 24 to the major wall 22 such that the widest portion of the converging wall 26 has an increased thickness of up to three inches. Once again, the interior volume of open core 28 is maintained at greater than 0.45 cubic feet, while the volume of the central core 28 remains equivalent to the open core 15 of block element 11 .
It should also be noted that any variation of the exterior size of the individual block elements 20 would affect handling and versatility of the block element 20 by the user (such as a mason). That is to say, masons are accustomed to handling conventional concrete blocks which are 18″×8″×12″, thus the present block elements 20 are designed to maintain the block elements 20 close to the same dimensions. Additionally, with the existing dimensions, the block elements 20 can be readily adjusted in relation to each adjacent block element 20 to form a serpentine or faceted retaining wall 30 (see FIG. 5) which can follow a contour along eighteen-inch segments.
Looking at FIGS. 4 and 5, the retaining wall 30 made of block elements 20 is strengthened using an anchoring composition 31 , preferably comprised of a plurality of anchoring stones 32 . Generally, the anchoring composition 31 is distributed into the open core 28 to provide a “positive connection” between adjacent block elements 20 . The positive connection created by the anchoring stones 32 will resolutely tie each block element 20 to the block elements 20 positioned above and below to form the steadfast retaining wall 30 . Consequently, this anchoring composition 31 joins the vertically abutting block elements 20 to provide the resolute and securely positioned retaining wall 30 .
Continuing to look at FIGS. 4 and 5, the preferred embodiment of the process for preparing the retaining wall 30 begins with the user arranging various block elements 20 in the number of multi-tiered rows as desired. The rows of the block elements 20 abut a backfill or other reinforced zone 8 . Additionally, a mesh mat or grid 9 is preferably placed between rows of the block elements 20 to further secure the assembly to the ground surface 8 . Each row of block elements 20 should preferably be offset a desired amount when compared to the abutting rows of block elements 20 .
In the preferred embodiment, the typical retaining wall 30 is assembled as follows, although the designs of retaining walls are varied as according to the stresses that are applied to the walls. Initially, a first row or course of block elements 20 is aligned on a foundation, with the block elements 20 being aligned in the desired manner with respect to each other. A second row of block elements 20 is further aligned on top of the first row of block elements 20 . The user then distributes the anchoring stones 32 into the open central cores 28 of the block elements 20 of the second row of block elements 20 in the retaining wall 30 . The anchoring stones 32 will descend through the central cores 28 of the block elements 28 in both the first and second rows due to gravitational pull and aggregate the anchoring stones 32 within the block elements 28 . This aggregation of anchoring stones 32 in the central cores 28 will reinforce and lock the position of the retaining wall 30 , and the anchoring stones 32 may be compacted within each row or course of block elements 20 such that they form a mechanical interlock between adjacent rows or courses of block elements 20 . The anchoring stones 32 are preferably conventional natural rocks or consecrations of mineral material, with the anchoring stones 32 varying in size from small pebbles to rocks having approximately a one inch diameter. In addition, the anchoring stones 32 may be either natural or made of other synthetic materials having the desired rigidity and strength properties required for the present application.
Once the anchoring stones 32 have traversed the central cores 28 to secure the position of the initial rows of the retaining wall 30 , the backfill material 8 is distributed proximate the retaining wall 30 such that the backfill material 8 is level with the uppermost edge of the second row of block elements 20 . The mesh grid 9 is then placed substantially on the second row of block elements 20 and the backfill material 8 . A third row of block elements 20 is further positioned on top of the second row of block elements 20 and the mesh grid 9 and properly aligned. To provide the positive connection and enhance the mechanical lock, the user will then pour a liquid resin 34 into the open central cores 28 of the block elements 20 of the third row of block elements 20 . The synthetic resin 34 will distribute around the mesh grid 9 and into the interstices surrounding the various anchoring stones 32 . The viscosity of the thick resin mixture 34 is such that it slowly spreads out over the mesh grid 9 and penetrates into the anchoring stones 32 below the mesh grid 9 . The open central cores 28 of the third row of block members 28 are ten filed with additional anchoring stones 32 which comes into contact with liquid resin 34 .
Consequently, the resin 34 will form the positive connection between the anchoring stones 32 , the mesh grid 9 , and the block elements 20 to form a positive interlock in a unitized structure. More specifically, once the synthetic resin 34 becomes motionless, it will coagulate or harden into a mass within the central cores 28 and around the anchoring stones 32 and the mesh grid 9 to form the positive connection. The coagulated synthetic resin 34 will reduce the amount of undesired redistribution of anchoring stones 32 in the retaining wall 30 . Moreover, the coagulated synthetic resin 34 will lock the mesh grid 9 within the retaining wall 30 and will not allow the mesh grid 9 to be pulled out of the retaining wall 30 , thus creating the positive connection between the mesh grid 9 and the block elements 20 . It is to be noted that this process may be repeated for as many courses or levels of block members 20 as may be desired. Furthermore, it should be noted that the coagulated synthetic resin 34 also minimizes the loss of the anchoring stones 32 from the retaining wall 30 by keeping the anchoring stones 32 secured in place.
The synthetic resin 34 used in the present invention can be one of various types of resin materials having properties to transform from a liquid state to a solid state. For example, the synthetic resin 34 used in the present invention may be any one of the following: orthopathalic based polyester resin (unsaturated); isophthalic based polyester resin (unsaturated); dicyclopentadiene based polyester resin (unsaturated); vinyl ester based polyester resin (unsaturated); bisphenol epoxy vinyl ester resin, urethane-modified vinyl ester resin; elastomer-modified vinyl ester resin; biphenol fumarate polyester resin; terephthalic based polyester resin; epoxy resin; fumaric anhydride based polyester resin; polyurethane foaming resin; urethane elastomer resin; and adipic acid based polyester resin. Any and all combinations of these various synthetic resins 34 may be used in the anchoring composition 31 . These synthetic resins 34 are helpful in that they are resistant to mildew, aging, and abrasion, so they will therefore maintain the positions of the surrounding stones 32 . Furthermore, the synthetic resins 34 are virtually nonbiodegradable, such that the user will not be concerned with repeating the steps of dispensing the synthetic resin 34 in the central core 28 after a period of time.
Additionally, the block elements 20 described herein may be produced in a block-molding machine (not illustrated), as is well known. Preferably, the mold (not illustrated) is loaded with a selected mix of concrete or cement, and the mixture is set to form two block elements 20 simultaneously in a “siamese” pattern. Once the mixture has formed and cured, the block elements 20 may be split along the joined major faces 22 to form two trapezoidal split face block elements 20 . Likewise, the block elements 20 may be formed from suitable plastic materials such as ABS or PVC by extrusion or molding. Decorative aluminum castings suitable for use as block elements 20 may be made by the lost foam casting method as is well known.
It should further be noted that the positive connection created through the use of the anchoring stones 32 , synthetic resin 34 , and mesh grid 9 reduces problems commonly found in conventional retaining walls. For example, when an excessive or unusual pressure is applied to conventional retaining walls to push the retaining wall forward, the mesh grid 9 frequently has a tendency to slide outward from between courses or levels of block elements 20 (which is called “pull out”). In the present invention, however, the positive connection created through the use of resin 34 with the anchoring stones 32 significantly increases the resistance of the mesh grid 9 to pull out from the retaining wall. Moreover, it should be noted that the mesh grid 9 may be placed on every other row of block elements 20 such that the positive connection is important to prevent the pull out of the mesh grid 9 between any of the rows of block elements 20 .
Thus, although there have been described particular embodiments of the present invention of a new and useful IMPROVED RETAINING WALL ASSEMBLY, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.
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A retaining wall assembly includes a plurality of block elements having a major face wall and minor face wall and a pair of opposing converging walls connecting the major face wall and the minor face wall. The block elements are arranged in multiple rows with a mesh grid separating predefined rows of block elements. The block elements define an open core into which a plurality of anchoring stones are distributed. A synthetic resin is also dispersed in the open cores of the block elements to provide a positive connection between the anchoring stones and the mesh grid, thereby reinforcing the position of the retaining wall.
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FIELD OF THE INVENTION
[0001] The invention relates to the field of mixing devices, especially mixing devices used for household appliances like food processors, hand blenders and/or hand mixers.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 3,656,718 describes an electrical domestic mixer for foods and ingredients of foods comprising a housing, beater means including a first and a second hollow shaft members supported in journaled relationship in said housing and extending downwardly from said housing, said shafts being substantially parallel, a helical blade member secured to each of said shafts and extending along the lower length thereof, said blade members having oppositely spiralled multicurved lands of substantially uniform radius disposed in interdigitating relationship and secured along their inner edges to their respective shafts, and driving means within said housing for rotating said shafts in opposite directions. The mixer described in U.S. Pat. No. 3,656,718 is adapted to operate with highly viscous materials, particularly those which are kneaded without aeration. The helical blades interact with each other so as to perform a mixing or kneading function which drives the material vertically downwardly and upwardly depending on their relative locations with respect to the rotation of the drive shafts. Relating to the functionality of this electrical domestic mixer it is very difficult or even not possible to mix small quantities of foods and ingredients of foods.
SUMMARY OF THE INVENTION
[0003] It is an object of the invention to provide a mixing device with which it is possible to even mix small quantities of mixable substances with good results.
[0004] The mixing device according to the invention for mixing mixable substances comprises aerating means with a rotational axis adapted to add air to the mixable substances and screw-shaped feeding means with a rotational axis adapted to transport mixable substances at least partly into the direction of the aerating means.
[0005] The mixing device is adapted to mix all possible mixable substances. Preferably the mixing device is adapted to mix mixable substances, like foods and ingredients of foods. In an operating mode the aerating means rotates around its rotational axis. The aerating means are formed as at least one beater, like a balloon beater, or a whisk. The aerating means mixes the mixable substances and adds air to the mixable substances, which is especially important by processing foods, like egg whites or cream. To increase the mixability of especially small quantities of mixable substances a screw-shaped feeding means is provided, which transport at least partly the mixable substances into the direction of the aerating means. Thus, the screw-shaped feeding means feeds the aerating means with the mixable substances. The screw-shaped feeding means provides very good conveying characteristics for mixable substances. The screw-shaped feeding means may easily lift up the mixable substances and may feed the mixing element with the lifted up mixable substances, which is essential for processing small quantities and additionally increases the beating effect of the mixing means while reducing the processing time. The screw-shaped feeding means lifts the mixable substances up and thru centrifugal forces the lifted mixable substances are transported towards the aerating means, which causes an additional volume increase of the actually mixed substances and better mixing results and thereby reduces the processing time. Thus, the mixable substances are transported by the screw-shaped feeding means vertically and horizontally relating to the rotational axis of the screw-shaped feeding means. In an operating mode the aerating means and the screw-shaped feeding means rotate around their rotational axis. Preferably, the screw-shaped feeding means and the aerating means rotate in the same direction. Furthermore, it is possible that the mixing device provides more than one aerating means and/or more than one screw-shaped feeding means. The screw-shaped feeding means and/or the aerating means may be made of any possible material, for example of a metal material, a plastic material, a glass material, a wood material and/or a ceramic material.
[0006] In a preferred embodiment of the invention, the rotational axis of the aerating means is arranged substantially parallel to the rotational axis of the screw-shaped feeding means. Preferably, the rotational axis of the aerating means corresponds to the longitudinal axis of the aerating means and the rotational axis of the screw-shaped feeding means corresponds to the longitudinal axis of the screw-shaped feeding means. Since the rotational axis of the aerating means is arranged substantially parallel to the rotational axis of the screw-shaped feeding means the transport of mixable substances by the screw-shaped feeding means into the direction of the aerating means has a high efficiency so that it is possible to achieve very good results by mixing small quantities of mixable substances.
[0007] According to another preferred embodiment of the invention the aerating means and/or the screw-shaped feeding means are driven by at least one drive unit. Preferably, both the aerating means and the screw-shaped feeding means are actively driven. It is possible that the aerating means and the screw-shaped feeding are separately driven, which means that the aerating means is provided with a drive unit and the screw-shaped feeding means is provided with a drive unit. This has the advantage that the aerating means and the screw-shaped feeding means are driven independently from each other. It is also possible, that only one drive unit is provided for both the aerating means and the screw-shaped feeding means so that the construction effort and the manufacturing costs of the device can be reduced. The drive unit is preferably a motor unit. But, it is also possible that the drive unit is hand driven preferably comprising a crank.
[0008] If only one drive unit is provided for both the aerating means and the screw-shaped feeding means it is preferred that the screw-shaped feeding means and the aerating means are coupled by transaction means. By providing transaction means only one drive unit is needed, which allows a reduction of costs of the mixing device.
[0009] Preferably, the transaction means is a gearing and/or a belt drive. The gearing may comprise at least two gear-wheels. Preferably, three gear-wheels are provided. At least one gear-wheel is connected with the rotational axis of the screw-shaped feeding means and at least one gear-wheel is connected with the rotational axis of the aerating means. For example, the screw-shaped feeding means is driven along its rotational axis by a drive unit, the rotation of the rotational axis of the screw-shaped feeding means is transmitted to the rotational axis of the aerating means by the gear-wheels, so that the aerating means is actively driven via the gearing. It is also possible to provide a belt drive, for example a tooth belt or a flat belt. Further it is possible to combine a gearing with a belt drive, for example using two gear-wheels which are connected by a belt drive. Using a gearing and/or a belt drive provides a simple implementation for transaction means.
[0010] According to another preferred embodiment of the invention the mixing means is arranged rotatable around the screw-shaped feeding means or the screw-shaped feeding means is arranged rotatable around the aerating means. Preferably, the aerating means is arranged rotatable around the rotational axis of the screw-shaped feeding means or the screw-shaped feeding means is arranged rotatable around the rotational axis of the aerating means. Thus, it is possible to provide three rotational movements in one mixing device within an operating mode, which allows better mixing results.
[0011] Preferably, the aerating means is rotatable clockwise and counter-clockwise around the screw-shaped feeding means, especially around the rotational axis of the screw-shaped feeding means, or the screw-shaped feeding means is rotatable clockwise and counter-clockwise around the aerating means, especially around the rotational axis of the aerating means. Thus, the rotation direction of the screw-shaped feeding means around the rotational axis of the aerating means or the rotation direction of the aerating means around the rotational axis of the screw-shaped feeding means is changeable. Preferably, the change of the rotation direction depends on the properties, especially on the viscosity, of the mixable substances and/or the mixture. The change of the rotation direction may be preformed automatically without the interference of an user of the mixing device. This rotation direction change may simulate the natural behavior of a user whisking a medium or a mixable substance. During the operation mode or application of the mixing device the viscosity of the mixable substance and/or the mixture regulates the rotation direction and thereby adjusts itself to its optimum processing parameters.
[0012] Furthermore, it is preferred, that the rotation speed of the aerating means by rotating around the screw-shaped feeding means, especially around the rotational axis of the screw-shaped feeding means, or the rotation speed of the screw-shaped feeding means by rotating around the aerating means, especially around the rotational axis of the aerating means, is adjusted automatically by self regulating. Preferably, the rotation speed is self regulating depending from the characteristics, especially the friction and viscosity, of the mixable substances. For example, if the viscosity of the mixable substances and/or the mixture raises the rotation speed decreases especially the rotation speed decreases until the rotation direction of the screw-shaped feeding means rotatable around the aerating means changes or until the rotation direction of the aerating means rotatable around the screw-shaped feeding means changes. After a rotation direction change the rotation speed increases again. During application or during the operation mode of the mixing device the rotation speed is self regulated by the characteristics of the mixable substances and/or the mixture and thereby the mixing device adjusts itself to its optimum processing parameters of the mixable substances. The term self regulating means that the rotation speed adjusts itself without an interfering of the user of the mixing device. Thus, by the self regulated rotation speed, the rotation speed adjusts itself to the respective optimum rotation speed regarding the current characteristics of the mixable substances and/or the mixture. Hence, optimum mixing results are obtained.
[0013] In another preferred embodiment of the invention, the aerating means is connected with the screw-shaped feeding means by a rigid connecting element. The connecting element may be formed as a rectangular-shaped and or round-shaped bar, rod, profile or arm and the connecting element may be made of a metal or a plastic material. The connecting element may provide a constant distance between the screw-shaped feeding means and the aerating means and a precise guidance of the screw-shaped feeding means and the aerating means to each other. The connecting element may be fixed to the rotational axis of the screw-shaped feeding means and the rotational axis of the aerating means.
[0014] Preferably, the connecting element is arranged rotatable around the screw-shaped feeding means, especially around the rotational axis of the screw-shaped feeding means, or the connecting element is arranged rotatable around the aerating means, especially around the rotational axis of the aerating means. It is possible that the aerating means is in a fixed position with the connecting element, whereas the connecting element is fixed to the screw-shaped feeding means rotatable around the rotational axis of the screw-shaped feeding means. Thus, the aerating means is rotatable around the rotational axis of the screw-shaped feeding means via the connecting element. Furthermore, it is possible, that the screw-shaped feeding means is in a fixed position with the connecting element, whereas the connecting element is fixed to the aerating means rotatable around the rotational axis of the aerating means. Thus, the screw-shaped feeding means is rotatable around the rotational axis of the aerating means via the connecting element. The connecting element may provide a precise guidance of the rotatable screw-shaped feeding means or the rotatable aerating means. The connecting element is driven separately from the rotational movement of the screw-shaped feeding means around its rotational axis and from the rotational movement of the aerating means around its rotational axis. Preferably, the connecting element is driven by a motor unit to conduct a rotational movement.
[0015] According to a further embodiment of the invention, the screw-shaped feeding means is mounted along its rotational axis at at least two points. Preferably, the screw-shaped feeding means is mounted at one end along its rotational axis and at the opposite end of the one end along its rotational axis. By mounting the screw-shaped feeding means at two points, the feeding means may be centered in a predefined position. The screw-shaped feeding means is preferably mounted at at least one point of these two points by a pin.
[0016] Preferably, the screw-shaped feeding means comprises at least one screw flight, wherein the at least one screw flight comprises at least one section with a screw pitch of zero degrees. Providing the screw flight with at least one section with a screw pitch of zero degrees undercuts at the screw flight may be prevented. It is preferred, that the at least one screw flight provides more than one thread, wherein each thread provides at least one of the at least one section with a screw pitch of zero degrees. By providing each thread with at least one section with a screw pitch of zero degrees the screw-shaped feeding means may be demoulded during die cast production with a simple two-part tooling without the need of sliders. Thus, it is possible to use cheap die cast methods for a simple and a cheap production of the screw-shaped feeding means.
[0017] Preferably, each thread provides two sections of the at least one section with a screw pitch of zero degrees. The other sections than the at least one section with a screw pitch of zero degrees provide a screw pitch of more than zero degrees, especially a screw pitch between 30 and 50 degrees. Preferably, the at least one of the at least one section with a screw pitch of zero degrees is positioned at the same position for each thread so that these sections with a screw pitch of zero degrees are lined on top of each other.
[0018] The invention further relates to a screw with the embodiments as described above.
[0019] Another aspect of the invention is a food processor comprising a mixing device as described above. The food processor may comprise a bowl, where the mixable substances may be mixed with the mixing device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
[0021] In the drawings:
[0022] FIG. 1 is a schematic view of an embodiment of a mixing device according to the invention;
[0023] FIG. 2 is a schematic view of the mixing device shown in FIG. 1 being part of a food processor;
[0024] FIG. 3 is a schematic view of a first embodiment of the screw-shaped feeding means according to the invention;
[0025] FIG. 4 is another schematic of the first embodiment of the screw-shaped feeding means shown in FIG. 3 ;
[0026] FIG. 5 is a schematic view of a second embodiment of the screw-shaped feeding means according to the invention; and
[0027] FIG. 6 is another schematic view of the second embodiment of the screw-shaped feeding means shown in FIG. 5 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] FIG. 1 shows a schematic view of an embodiment of a mixing device 10 according to the invention. The mixing device 10 comprises aerating means 12 with a rotational axis 14 and screw-shaped feeding means 16 with a rotational axis 18 . The aerating means 12 is formed as a balloon beater. The aerating means 12 is positioned next to the screw-shaped feeding means 16 , whereas the rotational axis 14 of the aerating means 12 is arranged parallel to the rotational axis 18 of the screw-shaped feeding means 16 . The aerating means 12 and the screw-shaped feeding means 16 are actively driven, wherein the aerating means 12 and the screw-shaped feeding means 16 are coupled by transaction means, like a gearing 20 . The gearing 20 comprises three gear-wheels 22 , 24 , 26 , wherein a first gear-wheel 22 is positioned at the rotational axis 14 of the aerating means 12 , a second gear-wheel 24 is positioned at the rotational axis 18 of the screw-shaped feeding means 16 and a third gear-wheel 26 is positioned between the first gear-wheel 22 and the second gear-wheel 24 . Thus, in this embodiment it is sufficient to drive the screw-shaped feeding means 16 and the aerating means 12 by a drive unit (not shown), like a motor unit, via the rotational axis 18 of the screw-shaped feeding means 16 . The aerating means 12 may rotate around its rotational axis 14 in the same direction as the screw-shaped feeding means 16 may rotate around its rotational axis 18 . Further, it is possible that the aerating means 12 may rotate around its rotational axis 14 in a different direction as the screw-shaped feeding means 16 may rotate around its rotational axis 18 . Preferably, the aerating means 12 and the screw-shaped feeding means 16 rotate clockwise.
[0029] The aerating means 12 and the screw-shaped feeding means 16 are connected by a rigid connecting element 28 , formed like an arm. The connecting element 28 is free to rotate around the rotational axis 18 of the screw-shaped feeding means 16 . The aerating means 12 is guided by the connecting element 28 to rotate around the rotational axis 18 of the screw-shaped feeding means 16 . The connecting element 28 and thus the aerating means 12 are free in its rotation direction around the rotational axis 18 of the screw-shaped feeding means 16 . The rotation direction changes between clockwise and counter-clockwise. Moreover, the rotation speed of the connecting element 28 and the aerating means 12 around the rotational axis 18 of the screw-shaped feeding means is adjusted automatically by self-regulating. The rotation speed and the rotation direction of the connecting element 28 and the aerating means 12 depend for example on the viscosity of the mixable substances. While the viscosity of the mixable substances raises the rotation speed decreases until the rotation direction of the connecting element 28 together with the aerating means 12 changes, for example a change from clockwise to counter-clockwise. After a change of the rotation direction the rotation speed increases again.
[0030] To center the screw-shaped feeding means 16 in a predefined position the screw-shaped feeding means 16 is mounted at two points 30 , 32 along its rotational axis 18 . One point 30 is at one end along the rotational axis 18 of the screw-shaped feeding means 16 and the other point 32 is at the opposite end of the one end along the rotational axis 18 of the screw-shaped feeding means 16 . The feeding means 16 is preferably mounted at the point 32 at the opposite end along its rotational axis 18 by a pin. But, it is also possible that the screw-shaped feeding means 16 is mounted only at one point 30 , 32 along its rotational axis 18 , preferably at the point 30 in the area of the transaction means.
[0031] FIG. 2 shows the mixing device 10 positioned in a bowl 34 of a food processor 36 .
[0032] FIGS. 3 and 4 show a possible first embodiment of the screw-shaped feeding means 16 . The screw-shaped feeding means 16 comprises a screw flight 38 , wherein the screw flight 38 provides more than one thread. One thread of the screw flight 38 extends 360 degrees around the body 40 of the screw-shaped feeding means 16 . Each thread preferably provides four sections, wherein two sections 42 of these four sections provide a screw pitch of zero degrees. The other two sections 44 of these four sections provide a screw pitch of more than zero degrees, preferably a screw pitch between 30 and 50 degrees. As it can be seen in FIGS. 5 and 6 the screw-shaped feeding means 16 may provide two screw flights 38 , wherein each screw flight 38 provides more than one thread, wherein each thread preferably provides four sections, wherein two sections 42 provide a screw pitch of zero degrees. Using sections 42 with a screw pitch of zero degrees the screw-shaped feeding means 16 may be demoulded during die cast production, whereas the demouldable direction is shown by arrow 46 in FIG. 4 , with a simple two-part tooling without the need of sliders. The at least one of the at least one section with a screw pitch of zero degrees is positioned at the same position for each thread so that these sections with a screw pitch of zero degrees are lined on top of each other, as it can be seen in FIGS. 3 and 4 .
[0033] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive, the invention is not limited to the disclosed embodiments.
[0034] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
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A mixing device ( 10 ) for mixing mixable substances, comprising aerating means ( 12 ) with a rotational axis ( 14 ) adapted to add air to the mixable substances and screw-shaped feeding means ( 16 ) with a rotational axis ( 18 ) adapted to transport mixable substances at least partly into the direction of the aerating means ( 12 ). With the inventive mixing device ( 10 ) it is possible to provide a mixing device ( 10 ) with which it is possible to even mix small quantities of mixable substances with good results.
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This is a divisional of application Ser. No. 08/311,101 filed on Sep. 23, 1994, now U.S. Pat. No. 5,521,099.
BACKGROUND OF THE INVENTION
The present invention relates to the detection and concentration measurement of combustible gases including, for example, the detection and measurement of concentrations of combustible gases in ambient air and, more particularly, to a combustible-gas sensing method employing a gas sensing apparatus having a relatively pure noble metal or noble metal alloy sensing element that, when maintained at a predetermined elevated temperature, exhibits the ability to react with combustible gases that otherwise would have little or no affinity for the sensing element.
Current sensor methods for monitoring and controlling combustible gases and their by-products employ sensors that suffer from at least one of the following drawbacks: poor long-term stability; need for frequent maintenance and calibration; low sensitivity to the gas being monitored; and high sensitivity to common interference gases including water vapor, with the latter being perhaps the most serious deficiency for many environmental applications.
For example, semiconductor gas sensors are normally plagued by high sensitivity to interference gases present in ambient air, such as common solvents and water vapor. Especially serious is the interference caused by water vapor, which is present in virtually all ambient air and which has a similar effect on semiconductor sensors as the target combustible gases such devices are intended to detect. U.S. Pat. No. 4,911,892 to Grace et al. (the '892 patent) discloses a semiconductor gas detection apparatus having enhanced capability for rejecting interference gases. Although improvements to semiconductor sensors such as those disclosed in the '892 patent may help to limit error, the semiconductor gas sensor's inherent sensitivity to common interference gases remains.
U.S. Pat. No. 3,714,562 to McNerney and U.S. Pat. No. 5,010,021 to Bell et al. disclose a gas detection method using a sensor comprising a relatively pure thin noble metal film sensor element selected for its chemical affinity for the target gas to be detected (hereinafter "metal affinity" gas sensors). When a sample mixture containing the target gas is passed over the sensor, the target gas adsorbs onto the surface of the sensor element causing the sheet resistance of the element to change. This resistive change is measured and, by comparison to a data base, converted into concentration units.
Metal affinity gas sensors do not exhibit the same sensitivity to water vapor as do semiconductor gas sensors. They are, however, limited to detecting target gases that have a natural affinity for the sensor surface at ambient temperature and they cannot be used by themselves to sense dynamic changes in concentration of the target gas because the sensor element surface reacts with the target gas to form stable surface species. These stable species saturate the sensor surface and, once its surface is saturated, the sensor cannot be used until it is regenerated, for example, by heating to desorb the compounds, or by rinsing with ozone.
Combustible gases, such as most hydrocarbons, which are able to react readily with oxygen, are critical to human existence. Because they represent a major source of energy as well as raw materials, these substances are essential to many industrial activities. However, their widespread use generates various hazards ranging from pollution to toxicity and even fire and explosion. Combustion is a major source of air pollution, much of which could be reduced by timely sensing of combustion products to indicate an out-of-specification combustion condition, and, of course, explosion caused by undetected leakage of combustible gases is an all-too-common occurrence. Unfortunately, shortcomings inherent in current gas sensor methods and devices have prevented widespread use of sensors capable of continuous operation to monitor combustible gases to avoid these and other similar occurrences.
For the foregoing reasons, there is a critical need for a combustible gas sensor that can be used continuously to detect and determine the concentration of a wide variety of combustible gases in the atmosphere or in a gas stream without being subject to false alarms caused by water vapor or other interference gases, yet having high sensitivity, fast dynamic response to changes in concentration, and the ability to distinguish between a variety of combustible gases.
SUMMARY OF INVENTION
The present invention is a method and apparatus that satisfies the need for a gas sensor that meets the foregoing requirements. The invention takes advantage of the fact that certain noble metals are able to become "oxygen activated" when maintained above a certain threshold temperature (the "oxygen activation temperature") and exposed to a gaseous mixture containing oxygen. By "oxygen activated" it is meant that these metals are able to dissociate oxygen gas in the mixture and adsorb the resulting atomic oxygen onto their surfaces without forming stable oxides; and once oxygen activated, they are able to react with combustible gases that otherwise would have little or no affinity for these metals. These metals will remain oxygen activated in the presence of oxygen over a range of temperatures above the oxygen-activation temperature up to a second threshold temperature (the "oxygen dissociation temperature") above which surface oxygen atoms recombine into oxygen gas and are desorbed from the surface. Above the dissociation temperature, the metals exhibit little or no enhanced reactivity with combustible gases. At various temperatures between the oxygen activation temperature and the oxygen dissociation temperature, oxygen-activated metals exhibit varying degrees of enhanced reactivity caused by the effect of temperature on the ability of the target gas species to adsorb on the metal surface before reacting with the surface oxygen.
According to the present invention, a target combustible gas is detected and its concentration measured by exposing a gaseous mixture containing oxygen to a noble metal sensor element maintained at a preselected temperature between the metal's oxygen activation temperature and its oxygen dissociation temperature. A baseline measurement of an electrical property of the sensor element, such as its work function, is taken after the surface has become oxygen activated. As a target combustible gas is introduced into the mixture, or as the sensor is introduced into a mixture already containing a combustible gas, the work function of the sensor element changes as the combustible gas reacts with the oxygen-activated surface of the sensor element. The work-function change is directly related to the concentration of the combustible gas within the mixture and is used to derive a concentration measurement.
The surface reactions of the sensor element are dynamic, that is, the reactions are ongoing with the sensor surface being continuously replenished with oxygen from the gaseous mixture. Therefore, the work function of the sensor element responds almost instantaneously to any changes in the concentration of the combustible gas within the mixture. When used in this manner, a single sensor element is able to determine the instantaneous concentration of a single known combustible gas or to detect the presence of a plurality of combustible gases individually or in combination.
Of particular interest, however, are that the work function response of a given sensor element as a function of temperature varies uniquely depending on the species of combustible gas within the mixture and that different sensor element materials exhibit different responses to the same combustible gas. Accordingly, in addition to being capable of measuring concentration of a known combustible gas, a single sensor element is capable of distinguishing between various combustible gases based on their work-function "signatures." An array of sensor elements of different materials at different temperatures would be capable of determining the identity and concentration of a plurality of combustible gases within the same mixture.
An object of the present invention, then, is to utilize the oxygen activation phenomenon as the basis for a gas sensor having improved sensitivity for target gases with decreased sensitivity to interference gases.
Another object is to provide a highly sensitive combustible gas sensor capable of continuous operation under ambient conditions and having wide detection capability.
A further object is to provide a noble metal gas sensor capable of determining the identity and concentration of various target gases.
BRIEF DESCRIPTION OF THE DRAWINGS
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from a consideration of the following detailed description of the presently-contemplated best mode of practicing the invention, by reference to a preferred embodiment of the invention disclosed in conjunction with the accompanying figures of drawing, in which:
FIG. 1(a)-(e) illustrates one theoretical stepwise mechanism for the oxygen-activation process exploited by the present invention.
FIG. 2 is a schematic drawing of an electrical circuit for utilizing the combustible-gas sensor element in FIG. 1.
FIG. 3 is a perspective view of an illustrative embodiment of a sensor element used in the present invention.
FIG. 4 is a plan view of an illustrative embodiment of a reference element used in the present invention.
FIG. 5(a)-(b) are cross sectional views of an illustrative embodiment of an apparatus embodying the present invention.
FIG. 6 is a response curve showing the work-function changes of a gold-film sensor as a function of temperature in air, oxygen, and nitrogen.
FIG. 7 is a response curve showing work-function changes of a gold-film sensor heated to 250° C. as a function of time upon exposure to 50 parts per million of ethanol in air for 1 minute.
FIG. 8 is a response curve showing the work-function changes of a gold-film sensor as a function of temperature upon exposure to 10, 100, and 1,000 parts per million of methane.
FIG. 9 is a response curve showing the work-function changes of a gold-film sensor as a function of temperature upon exposure to 10, 100, and 1,000 parts per million of ethanol.
FIG. 10 is a response curve showing the work-function changes of a gold-film sensor as a function of temperature upon exposure to 10, 100, and 1,000 parts per million of carbon monoxide.
FIG. 11 shows the work-function response of a gold-film sensor to ethanol as a function of ethanol concentration at 178° C., 266° C., 317° C., and 355° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
When a noble metal is oxygen activated, the surface-adsorbed oxygen reacts readily with combustible gases, where present, to form quasi-stable surface intermediate products. These intermediate products then react to form stable oxidation products that are driven off the surface and replaced by more atomic oxygen. Oxygen activation occurs only with noble metals. Transition metals, such as cobalt, nickel and copper form stable oxides and so cannot be used as oxygen-activated sensor elements.
Referring to FIG. 1, it is believed that the surface reactions proceed according to a generalized acid-base reaction. FIG. 1(a) contains a representation of a noble metal surface 10 having molecules 11 at the surface. The metal surface 10 is shown at a temperature below its oxygen-activation temperature, exposed to a gaseous mixture 12 that contains oxygen. Below its oxygen-activation temperature (T o ), the exposed metal surface 10 neither dissociates oxygen from the gaseous mixture nor exhibits a tendency to react readily with the target combustible gas. FIG. 1(b) illustrates the oxygen activation of the metal surface 10 at a temperature above T o , at which the surface causes the dissociation of oxygen gas (O 2 ) and adsorbs the atomic oxygen (O) onto its surface.
In FIG. 1(c), the target gas BH, contained in gaseous mixture 12, is adsorbed and dissociated on the metal surface 10. This surface reaction proceeds according to the general acid-base reaction BH(g)+O a →B a +(OH) a , where B is the residual resulting from the dissociation of a BH molecule and OH is the hydroxyl species resulting from the partial oxidation of hydrogen from the BH molecule. The subscript "a" refers to the status of the chemical species as being adsorbed on the surface.
FIG. 1(d) is a representation of the adsorption and dissociation of a second molecule of BH on the metal surface 10. Finally, referring to FIG. 1(e), the metal surface 10 is shown as regenerated for another cycle of operation by the oxidation of the residual B on the metal surface by O 2 in the gaseous mixture.
Since only the metal surface participates in the oxygen-activation process, the metal can be in the form of a thin film, thick film, foil, or plate. The thin-film form is preferred, however, because it is economical where precious metals are involved, permits greater design flexibility, and allows close conformity to differing surface contours.
The presence of atomic oxygen and other adsorbed products on the surface has an effect on the electrical properties of the noble metal surface itself. FIG. 2 is a schematic drawing of an electrical circuit 20 for detecting the change of one such property, the work function of surface 10. The circuit 20 includes a variable direct current (D.C.) voltage source 28, a means for detecting alternating current (A.C.), such as an ammeter 26, a stationary sensor surface 10 composed of gold, platinum or other noble metal or noble metal alloy that exhibits the capability of oxygen activation as described with reference to FIG. 1 above and a reference surface 22. Reference surface 22, composed of a material that is incapable of becoming oxygen-activated, for example chromium-contaminated gold or gold at a temperature below its oxygen activation temperature, is juxtaposed in a spaced-apart, confronting relationship to surface 10, and is adapted to be movable toward and away from the confronting surface 10, as further described with reference to FIG. 5 below, to create a parallel-plate capacitor in which the gap between the plates can be varied in a periodic fashion. Oscillation of the reference plate is preferred because the reference surface, in contrast to the sensor surface, is not heated. This arrangement allows both the heat loss from the sensor plate and the mass of the reference plate to be minimized. The sensor surface 10 and reference surface 22 function as a parallel-plate capacitor, with the gap between them allowing introduction of a gaseous mixture containing the combustible gas to be detected.
The charge on the capacitor plates is related to the capacitance, C, and the voltage across the capacitor, V, by the equation
Q=CV
Varying the gap between the plates in a fluctuating manner causes a fluctuating change in both the plate charge and capacitance resulting in a fluctuating current flow through the circuit 20 that is described by taking the derivative with respect to time of the above equation: ##EQU1##
The voltage V is comprised of V b , the bias voltage and Δ.O slashed., the difference in work function between the plates. Since the current, i, is the time derivative of the charge Q (i.e., dQ/dt), the above equation becomes: ##EQU2##
The work-function difference between the plates can be measured by adjusting the D.C. bias voltage from source 28 to reduce the alternating current measured by ammeter 26 to zero. In practice, instead of using an ammeter, both higher sensitivity and convenience of operation can be achieved by detecting and amplifying the alternating voltage associated with the alternating current by conventional means using, for example, a lock-in amplifier. The voltage output of the lock-in amplifier may also be fed into an automatic controller that is part of a feedback circuit loop to provide the appropriate bias voltage to maintain at all times a zero-current condition.
If the substrate of reference surface 22 is a magnetizable material, it can be made to vibrate by an alternating magnetic field produced by an electromagnetic coil driven by a frequency generator. It should be understood, however, that any means of inducing a variable capacitance between sensor surface 10 and reference surface 22 will accomplish the same result. It may also be possible to induce a periodic mechanical oscillation of reference surface 22 using piezoelectric means. Alternately, it may be possible to induce a variable capacitance by periodically altering the dielectric constant between the two surfaces, for example, by means of a variable dielectric material, or by using, as a reference, a semiconductor device such as a metal-insulator-semiconductor (MIS) structure, in which the dimension of the depletion layer can be modulated. Likewise, any capacitor configuration that permits gas flow between the sensor and reference element will also accomplish the same result. For example, the sensor and reference plates may be arranged concentrically.
FIG. 3 is a perspective view of an illustrative embodiment of the gas sensor element assembly 50 of the present invention. Substrate 42 is composed of alumina 2.5 cm long by 0.6 cm wide by 0.064 cm thick having a surface roughness of approximately 2 microns. The planar dimensions are unimportant: however, for good heat transfer, the thickness of the substrate should be kept to the minimum necessary for the structural integrity of the assembly. A thick-film resistive heater 44 is applied to one surface of the substrate by depositing resistive nickel in a serpentine pattern, having thick film silver electrodes 46. In an alternative embodiment, heater overglaze is applied by conventional means to the resistive heater 44 to permit sustained operation at temperatures of up to 500° C. It should be understood that the means for heating the sensor element is immaterial provided the appropriate temperature can be maintained. It would be equally acceptable to heat the gas stream itself to maintain the sensor element at the appropriate temperature. On the side of the substrate opposite the heater element, a thin-film noble-metal sensor element 40 is vapor deposited. The exposed surface of sensor element 40 comprises sensor surface 10, as described with reference to FIG. 2. For improved adhesion, a very thin film of chromium (less than about 50Å) can be deposited first, followed by a relatively thick (greater than about 1,000Å) film of noble metal. Typical thicknesses for the sensor elements are 500-6,000Å. Since the gas sensing occurs on the surface of the sensor element, however, the actual thickness is immaterial, as long as the noble metal film forms a continuous deposit on the substrate. Accordingly, sensor elements may be in the form of thin film, thick film, foil, or plate. Both gold and platinum sensor elements 40 have been made successfully by ordinary vapor deposition techniques.
FIG. 4 is a plan view of an illustrative embodiment of reference element assembly 70 of the present invention. Substrate 72 is composed of conventional spring steel. Reference body 74 is composed of a layer of chromium deposited on substrate 72 followed by a layer of gold. The surface of reference body 74 comprises reference surface 22 as described with reference to FIG. 2. The presence of the chromium layer underneath the gold allows chromium to diffuse through the gold film upon heating to temperatures up to 300° C., thereby contaminating the gold surface and disabling its ability to become oxygen activated. The chromium layer needs to be sufficiently thick to provide a stable reference surface for extended operation of the capacitor at elevated temperatures. Chromium films thicker than approximately 1,000Å provided a stable reference surface for several weeks at temperatures up to 500° C. Reference surfaces may also be prepared in several other ways, including by (i) depositing a relatively thick overlayer of chromium (greater than about 1,000Å) on gold followed by thermal annealing at temperatures up to 300° C.; (ii) depositing only a thick film of chromium; or (iii) using the bare surface of a stainless steel plate. Because only the exposed surface of the reference element must be incapable of becoming oxygen activated, the total thickness of the reference element is immaterial. Accordingly, reference elements may be fabricated in the form of thin film, thick film, foil, or plate. Chromiated reference surfaces can also be refurbished by further deposition of a relatively thick layer of chromium.
FIGS. 5(a) and 5(b) are cross-sectional views of an illustrative embodiment of the invention. Referring to FIG. 5(a), sensor element assembly 50 is supported by structure 80. Temperature probe 82 is a conventional thermocouple probe supported by structure 80 such that the thermocouple element of the probe is in contact with or in close proximity to sensor element 50. In lieu of a temperature probe, the power inputted to the heating element may also be used to derive a temperature. Reference element assembly 70 is supported at one end by arm 81 inserted into structure 80, reference element 70 forming a cantilever juxtaposed in a spaced apart confronting configuration parallel to element assembly 50. Reference element assembly 70 is caused to oscillate mechanically by subjecting it to an oscillating magnetic field produced by the extended metal core of an electromagnetic coil 84. In practice, an average separation between the sensor and reference surface of approximately 0.5-1.0 millimeters (mm), an oscillation amplitude of approximately 0.1-0.3 mm, and an oscillation frequency of about 500-1,000 Hertz produced an acceptable signal. However, it is desirable to minimize the average plate separation to maximize the capacitor signal, and it is also desirable to minimize the coil-to-reference element distance to reduce the power required to actuate the reference surface oscillation as well as to reduce the strength of any stray electromagnetic fields contributing to the background noise. A small average plate separation maximizes the capacitor signal because the amplitude of the reference plate motion, although small on an absolute scale, is large relative to the plate separation, thereby producing a large change in capacitance. A small average plate separation also allows higher oscillation frequencies to be used because of the small absolute amplitude necessary. Edge card connector 86 provides connections for power to resistance heater 44 and for the signal output from sensor element 40 to circuit 20. Shield 88 shields circuit 20 from interference.
FIG. 5(b) is a cross sectional view of an illustrative embodiment of the present invention through a plane orthogonal to the plane of the view in FIG. 5(a). Apertures 76 and 78 define a gas flow path through the structure permitting the gas to come into contact with the sensor element. The gas flow path may be connected to a pump or other means for forcing gas to flow past the sensor surface, or the apertures may be left disconnected, to allow natural circulation to bring the mixture into contact with the sensor surface.
Experimental data taken using alternate embodiments of the invention are summarized in FIGS. 6-11. FIG. 6 is a curve showing the work-function changes of an embodiment of the present invention using a gold-film sensor on alumina as a function of temperature in air or oxygen, as shown by line 90, and in nitrogen, as shown by line 92. When the sensor surface was heated in air from ambient temperature to approximately 200° C., its work function increased linearly by an amount on the order of microvolts per degree Celsius (μv/°C.). However, when the sensor reached approximately 200° C., the change in work function began to increase rapidly until reaching a temperature of about 320° C. Between these two temperatures a dramatic increase of over 1000 millivolts (mV) was obtained, as shown by the vertical scale line 94. An identical response was observed when the sensor was heated in pure oxygen, but not in nitrogen. In both air and pure oxygen, this increase is completely reversible and nonlinear. When, however, the experiment was performed in a nitrogen atmosphere, as shown by line 92, little change in the work function was observed when the sensor was heated from ambient to 350° C. However, when the sensor was maintained at 320° C. and oxygen introduced into the nitrogen atmosphere, the work function increased rapidly to approximately 1000 mV. Repeated exposure to nitrogen followed by air demonstrated that the response was reversible. Similar behavior has been observed for an alternate embodiment of the present invention utilizing a platinum-film sensor element, except that the onset of the increase in work function upon exposure to oxygen occurred at a lower temperature of approximately 150° C.
The increase in work function is strongly dependent upon the nature of the substrate. For example, a 6,000Å gold film on alumina sensor exhibited a 1,000 mV increase in work function on heating, whereas similar gold films on a very flat polyimide substrate showed only a 300 mV increase on heating. Since the gold surface is much smoother on the polyimide surface than on the highly granular alumina surface, the difference in response is believed to result from the different gold-film morphologies and defect structures produced by these substrates. It appears that the high grain boundary densities in granular metal films result in the largest response to oxygen as well as the highest sensitivity to combustible gases.
FIG. 7 is a curve 96 showing work-function changes of the preferred embodiment of the present invention where the gold-film sensor is heated to 250° C. as a function of time upon exposure to 50 parts per million ("ppm") of ethanol in air for one minute. Upon exposure of the sensor to ethanol, indicated by arrow 98, a stable steady-state signal of approximately 150 mV is developed within one minute, as may be seen by reference to arrow 100 and vertical scale line 102. Upon exposure to pure air, initiated at arrow 100, the sensor returns to the baseline also within about one minute. Since the response at the sensor surface is essentially instantaneous, the speed of response reflected in this experiment is that of the flow dynamics, not the sensor itself. The sensor response to ethanol occurs in the same temperature range as the oxygen-activation process, so that below about 200° C., which is the threshold temperature for oxygen activation of a gold surface, there was essentially no signal.
FIG. 8 is a group of curves showing work-function changes of a gold-film sensor embodiment of the present invention as a function of temperature upon exposure to 10 ppm of methane represented by the curve having (▴) symbols, 100 ppm of methane represented by the curve having () symbols and 1,000 ppm of methane represented by the curve having (▪) symbols. The response increases rapidly above about 200° C., which is consistent with the oxygen-activation process, whereby reactive oxygen adsorbed to the gold surface above 200° C. is then removed by reaction with methane. In contrast, no response was observed when an embodiment of the present invention incorporating a platinum-film sensor was used, which indicates that the activity of oxygen above the oxygen-activation threshold temperature for platinum (150° C.) is not sufficient to react with methane, demonstrating that different metal surfaces are capable of becoming oxygen activated to different degrees.
FIG. 9 is a group of curves showing work-function changes of a gold-film sensor embodiment of the present invention as a function of temperature upon exposure to 10 ppm of ethanol represented by the curve having (▴) symbols, 100 ppm of ethanol represented by the curve having () symbols, and 1,000 ppm of ethanol represented by the curve having (▪) symbols. The response at temperatures below the oxygen-activation threshold temperature of gold (200° C.) is believed to be due to adsorption of ethanol on the gold surface, since no response is observed when the ethanol is removed. At intermediate temperatures (200° C. to 300° C.) there are believed to be two competing reactions: ethanol adsorption/desorption and active oxygen that is removed by ethanol oxidation. At higher temperatures (greater than about 300° C.), it is believed that ethanol adsorption is absent, primarily because the gold surface is covered with active oxygen, so that the sole effect that causes the response is the decrease in active oxygen concentration. The same general considerations also apply to the response of an embodiment of the present invention incorporating a thin-film platinum sensor. Similar qualitative behavior also has been observed for the organic alcohol methanol, the ether ethyl ether, the ketone acetone and the alkene ethylene, except that the quantitative response curves are different for each gas and sensor metal combination. Therefore, by operating the sensor at a sufficiently high temperature above the oxygen-activation threshold temperature, active oxygen removal becomes the dominant reaction mechanism for organic combustible gases.
FIG. 10 is a group of curves showing work-function changes of the gold film sensor embodiment of the present invention as a function of temperature upon exposure to 10 ppm of carbon monoxide represented by the curve having (▴) symbols, 100 ppm of carbon monoxide represented by the curve having () symbols, and 1,000 ppm of carbon monoxide represented by the curve having (▪) symbols. The same considerations as discussed with reference to FIG. 9 also apply here, except that the adsorption of carbon monoxide at lower and intermediate temperatures causes a complete change in the sign of the response prior to the creation of a pronounced response maximum at higher temperatures (greater than about 300° C.). Similar qualitative behavior has been observed for an alternate embodiment of the present invention incorporating a thin-platinum-film sensor and also for exposure of both embodiments to hydrogen and ammonia, except that the quantitative response curves are different for each gas and sensor combination. These results suggest that the multicomponent analysis of several gases in a stream is feasible using a relatively simple sensor array consisting of two or more different sensors based upon the operating temperature of the individual sensors and their composition. Unlike other sensing methods, the sign as well as the magnitude of the signal at different temperatures can be used to speciate a mixture of gases.
FIG. 11 is a group of curves showing the response of the preferred embodiment of the present invention to ethanol as a function of ethanol concentration at various temperatures. The curve having (+) symbols represents the response of a sensor maintained at 178° C.; the curve having (▪) symbols, 266° C.; the curve having () symbols, 317° C.; and the curve having (▴) symbols, 355° C. The response varies approximately linearly with the logarithm of the concentration. This log-linear relationship is consistent with a steady-state balance between adsorption and desorption of molecules on the sensor surface and reduced response as surface sites for adsorption approach saturation at higher concentrations. The lower limit of detection is approximately 100 parts per billion, which is typical of most of the gases studied and is well below the detection level of existing solid-state combustible-gas sensors which generally are limited to detection ranges on the order of 50 ppm or more.
Based on an analysis of the response results, preferred operating temperatures that maximize the overall magnitude and speed of response have been established for both gold and platinum thin-film sensors on alumina substrates and are shown in Table 1.
TABLE 1______________________________________Preferred temperatures for combustible gas detectionusing alumina substrates. Temperature °C.Gas Platinum Film Gold Film______________________________________Ethanol >350 >350Acetone >350 >350Ether >350 >350Methanol >350 >350Ethylene >350 >350Methane .sup.a >350Carbon Monoxide 200 275Hydrogen 200 225Ammonia 130 80______________________________________ .sup.a Methane could not be detected in these experiments even at the highest sensitivities.
Although the foregoing data were collected using pure gold and pure platinum sensor surfaces, it follows from the above results that alloys of gold and platinum should also exhibit oxygen activation and, hence, be useful as materials for sensor elements for combustible gas detection. Other noble metals that are expected to demonstrate oxygen activation are silver, palladium, rhodium and iridium. Based on average oxygen desorption temperatures measured in ultra high vacuum experiments, the oxygen activation temperatures are expected to follow the order Ag<Au<Pt<Pd<Ir<Rh. Therefore, it is reasonable to expect that oxygen-activated thin-film sensors fabricated from these noble metals and/or alloys can function over a wide range of operating temperatures and combustible-gas concentrations to permit a wide range of applications.
Although the foregoing discussion has focused primarily on use of the present invention as a combustible gas sensor, it should also be noted that, because oxygen activation depends on oxygen being present in the gas stream, the present invention is equally capable of functioning as an oxygen sensor, as demonstrated by the reversibility of the reaction discussed with reference to FIG. 6. The present invention also may, under certain circumstances, function as an oxygen/fuel ratio sensor as well. However, because the present invention is capable of operating in gas streams at temperatures well below those at which Y 2 O 3 -doped solid-electrolyte-based solid-state devices operate, without being subject to false readings caused by moisture or other common interference gases, the present invention, if used for example as an air/fuel ratio sensor in an automobile engine control system, would provide nearly instantaneous feedback, thereby reducing or eliminating the period during which the engine must operate in an open-loop condition after a cold start.
The present invention overcomes the limitations in the prior art for combustible-gas detection by operating the noble metal sensor surface at an elevated temperature, which is required for oxygen activation, as well as by employing durable noble-metal sensor place surfaces, such as gold. By operating the sensor at elevated temperature: (1) the sensor can operate continuously and in real time without the sensor surface becoming saturated because the sensor surface is being regenerated continuously by oxygen in the gaseous mixture; (2) impurities desorb from the sensor surface at elevated temperatures, so that contamination effects are minimized; and (3) the sensor operation is unaffected by completely oxidized molecules in the gaseous mixture, such as carbon dioxide and water vapor, since no further oxidation of these molecules is possible. Furthermore, in the preferred embodiment, where work function, rather than some other property, is measured, the thicknesses of the sensor and reference films are immaterial, since only their surfaces contribute to the work-function response.
These innovations have achieved the desired reversible reactions at the sensor surfaces that have permitted circuit 20 to be used to evaluate the work-function change for several noble-metal sensor elements and combustible gases with a typical precision of ±3 mV. Although the preferred embodiment presently exploits change in work function to measure the instantaneous status of gas adsorption, other properties affected by gas adsorption, such as resistance, may also be exploited. Initial experiments have indicated that sufficiently thin films (less than about 1,000Å) are required for the detection of combustible gases by resistance methods. For example, at 250° C., an 800Å platinum film exhibited an increase in resistance from 6 MegaOhms (MΩ) to 10 MΩ in air and a further increase in resistance to 11 MΩ upon exposure to methanol at concentrations of several hundred parts per million.
Although certain preferred embodiments of the invention and methods of fabrication and implementation thereof have been described herein, it will be apparent to those skilled in the art from the foregoing description that variations and modifications of the disclosed embodiments and methods may be made without departing from the true spirit and scope of the invention. Accordingly, it is intended that the invention shah be limited only to the extent required by the appended claims and the rules and principles of applicable law.
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A combustible gas sensor having a noble metal sensor element with a surface that is heated above a critical temperature at which the surface is able to dissociate oxygen in a gas stream and adsorb the oxygen onto its surface. The adsorbed oxygen present on the noble metal surface enhances the reactivity of the sensor element and permits it to react with combustible gases that otherwise would have little or no affinity for the sensor element. The balance of adsorbed oxygen and combustible gas species on the sensor surface cause a change in an electrical property that is used to determine the presence or identity of a combustible gas, or to derive a concentration measurement. The electrical property measured to determine the presence, identity, or concentration of combustible gas includes the work function of the noble metal surface, which may be measured by incorporating the sensor element as a component of a variable capacitor contained in an electrical circuit adapted to measure change in current caused by the change in capacitance of the variable capacitor.
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This is a division of application Ser. No. 08/672,148, now U.S. Pat. No. 5,829,912, that was filed on Jun. 27, 1996 and is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for impeding the motion of a land vehicle. More particularly, a barrier is rapidly deployed through the rapid extension of telescoping supports.
2. Description of the Prior Art
The military and police officials are at times required to stop a moving land vehicle. For example, the military may be called on to stop a truck laden with explosives. The police may be called on to stop a speeding car containing suspected criminals. It is desirable that the occupants of these vehicles, that may include hostages, not be injured by immobilization of the vehicle. Therefore, immobilization by conventional methods such as road blocks using other vehicles and tire puncturing is not acceptable.
Devices to stop a moving land vehicle without injury to the occupants are disclosed in U.S. Pat. Nos. 4,576,507 to Terio et al. and in U.S. Pat. No. 4,824,282 to Waldecker, both of which are incorporated by reference in their entireties herein.
The Terio et al. patent discloses a pair of I-beams disposed on opposing sides of a roadway supported in an underground enclosure. Cables supported by shock absorbers extend between the I-beams. When the barrier is actuated, the I-beams rise from the underground enclosure, extending the cables across the roadway.
The Waldecker patent discloses a plurality of fabric cylinders disposed in a trench extending across a roadway. A net is supported on one side of these cylinders. When actuated, gas generators fill the cylinders causing them to rise and form a barrier across the roadway. Impact with the gas-filled cylinders serves as a primary braking means to impede the land vehicle. The net forms a secondary braking means.
While the above vehicle immobilization systems are useful, they have the disadvantage of being complex, heavy and immobile. They are useful for protection of a fixed target, but are less useful for protecting temporary targets, such as an arena being visited by a head of state. They are also not useful for rapid deployment in a remote site, such as encountered by police seeking to stop the escape of criminals.
There exists, therefore, a need for a transportable, rapidly deployed, vehicle immobilization system that does not suffer from the disadvantages of the prior art.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a vehicle immobilization system that is both transportable and rapidly deployed. It is a feature of this vehicle immobilization system that telescoping supports are rapidly extended by a propulsion unit. The telescoping supports may be either embedded in the ground or anchored above ground. A barrier extending between the telescoping supports permits free travel of land vehicles when the telescoping supports are compressed, but stops moving vehicles with a deceleration force of less than 2 g (twice the force of gravity) when the telescoping supports are extended.
Among the advantages of the vehicle immobilization system of the invention are that the system is both lightweight and transportable. The system is readily deployed as and where needed. A further advantage is that a moving land vehicle is not destructively immobilized facilitating the safe removal of the occupants.
In accordance with the invention, there is provided a transportable device for impeding the motion of a land vehicle that is travelling along a pathway. This device has first and second supports positioned at first and second sides of the pathway, respectively, each capable of being actuated from a compressed condition to an extended condition. A propulsion system is effective to actuate the supports. A barrier extends between the supports at a mean first height that is effective to permit passage of vehicles when the supports are compressed and held by each support at a mean second height effective to impede passage of a vehicle when the supports are extended. When the supports are compressed, vehicles pass over the barrier unimpeded. When the supports are extended, the barrier impedes the motion of a vehicle traveling along the pathway. At least one deceleration cable mechanically couples the barrier to a brake system.
In specific implementations of the invention, each support may have a housing, a first telescoping element, and a second telescoping element. The first telescoping element is moveable upward relative to the housing upon actuation of the associated support. The second element is concentric with the first element and moveable upward relative to the first element to reach an extended height upon actuation of the associated support. The barrier is supported by the second element of each support. The propulsion system may comprise a rapidly combusting chemical mix. The supports may be positioned so that their respective housings are atop and not substantially sunk into the ambient terrain so that majorities of the first and second telescoping elements are positioned above the terrain when the supports are in the compressed condition. The supports may each have a plurality of anchors effective to anchor the supports against force transmitted from the impact of the vehicle with the barrier. The anchors may be at least partially embedded in the terrain. The telescoping elements may be inner and outer intermeshed cylinders.
Prior to deployment, the barrier may be housed in a barrier enclosure. The barrier enclosure may have a top including first and second hinged cover elements. The cover elements may be moveable from a closed condition for storing the barrier beneath the top and protecting the barrier from vehicles passing over the enclosure to an open condition in which the barrier may be deployed upward through a gap between the cover elements.
In the closed condition, the cover elements may be separated by a convoluted separation line defining intermeshing inboard edges of the first and second cover elements. Such edges may be directed generally upward in the open condition and effective to puncture the tires of a vehicle passing over the enclosure. The enclosure may have a generally trapezoidal cross-section.
The deceleration cables may be configured to cross behind a vehicle which has collided with the barrier so as to extend along first and second sides of such vehicle and impede opening of the doors of such vehicle sufficiently to impede escape of occupants of the vehicle.
The above stated objects, features and advantages will become more apparent from the specification and drawings that follow.
IN THE DRAWINGS
FIG. 1 illustrates in partial cross-section the vehicle immobilization device of the invention prior to deployment.
FIG. 2 illustrates in top isometric view a portion of the device of FIG. 1.
FIG. 3 illustrates mechanisms for piercing the tires of a vehicle.
FIG. 4 illustrates in cross-sectional representation the device of FIG. 1 subsequent to deployment.
FIG. 5 illustrates in cross-sectional representation a telescoping support in accordance with the invention.
FIG. 6 illustrates in partial cross-section a mechanism for anchoring a telescoping support above ground.
FIGS. 7 through 11 schematically illustrate the operation of the vehicle immobilization device of the invention.
FIG. 12 schematically illustrates a braking system in accordance with an embodiment of the invention.
FIG. 13 schematically illustrates a braking system in accordance with a second embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 illustrates, in partial cross-sectional representation, a transportable device 10 for impeding the motion of a vehicle that is travelling along a pathway 12. While the pathway 12 is illustrated as a paved road, the invention is equally applicable to other pathways such as unpaved roads, rails and narrow waterways, such as canals.
The device 10 includes a first telescoping support 14 and a second telescoping support 16. The first telescoping support 14 and second telescoping support 16 are anchored to opposing sides of the pathway 12. Such anchoring may be by partial embedding in the ground 18 as illustrated in FIG. 1 or by explosively driven anchors as illustrated in FIG. 5.
The telescoping supports 14, 16 support a barrier 20 by a breakaway cord 21 or other detachable connection. When compressed, the telescoping supports 14, 16 extend the barrier 20 across the pathway 12 at a mean first height, D, that is typically between 0 inches (flush with the pathway) and 6 inches. Preferably, D is from 0 inches to 2 inches.
Preferably, both the first telescoping support 14 and the second telescoping support 16 are at the same height to support the barrier uniformly across the pathway 12. When extended by a suitable propulsion system, the first telescoping support 14 and second telescoping support 16 raise the barrier 20 to a height, D' (indicated as an alternate position in FIG. 1) above pathway 12.
The barrier 20 extends between the telescoping supports 14, 16. When the telescoping supports 14, 16 are compressed, the height of the barrier 20 above the pathway 12 is sufficiently low to permit passage of land vehicles, preferably, D is less than 2 inches. When the telescoping supports 14, 16 are extended, the barrier 20 is at a height effective to impede passage of vehicles. D' is dependent on the vehicle to be stopped, including the tire size and vehicle weight. Preferably, D' is at least equal to the diameter of the vehicle tires. For an all terrain vehicle or a truck, D' is more than 36 inches and preferably from about 48 inches to about 80 inches.
The device 10 further includes at least one deceleration cable 22 that mechanically couples the barrier 20 to a brake system 24. The deceleration cable is an extended length, high strength, flexible strand such as a rope, cable, chain or webbing that transfers momentum imparted by the land vehicle from the barrier 20 to the brake system 24. The deceleration cable 22 has a yield strength and an elongation capacity sufficient to avoid breaking when the barrier 20 engages a moving vehicle. Since the barrier 20 may be called on to stop a moving truck having a weight of several tons, the yield strength of the deceleration cable 22 should be sufficient to stop that vehicle. High strength nylon rope and steel cable are exemplary. A preferred material for the deceleration cable 22 is 2 inch wide webbing formed from nylon.
The momentum of the vehicle is dissipated by the brake 22 to non-destructively stop the land vehicle.
FIG. 2 illustrates in top isometric view, the device 10 prior to deployment. The telescoping supports 14, 16 are anchored to opposing sides of the pathway 12 and support the barrier 20 (shown in phantom). The barrier 20 is optionally housed within a barrier enclosure 26 that both protects the barrier from damage and facilitates the unimpeded passage of moving land vehicles.
The barrier enclosure 26 has the shape of a conventional speed bump, such as hemispherical or trapezoidal. The trapezoidal barrier enclosure 26 illustrated in FIG. 2 has gradually sloped surfaces 28 to guide a moving land vehicle over the barrier enclosure 26. Preferably, the barrier enclosure is a minimum height necessary to enclose the barrier 20. Typically, the barrier enclosure will extend from about 0 inch to about 6 inches above the pathway 12 and the surfaces 28 form an angle of between 0° and 15° with the pathway 12.
The barrier enclosure 26 is formed from any material having sufficient strength to withstand the passage of heavy land vehicles. Suitable materials include steel, aluminum and fiberglass. A top surface 30 is designed to avoid impeding deployment of the barrier 20. Preferably, the top surface 30 is hinged for accelerated opening. The top surface 30 may comprise two pieces separated by a jagged line 31. The jagged line forms pointed spikes or prongs on opening that are effective to pierce the tires of the vehicle.
FIG. 3 illustrates alternative mechanisms to pierce the tires of the vehicle to be stopped. The barrier enclosure 26 includes one or more piercing devices such as pointed spikes 32 or cutting blades 33 that are deployed when the top surface 30 opens.
FIG. 4 illustrates the device 10 with telescoping supports 14, 16 deployed and the barrier 20 at the mean second height D' above the pathway 12. The barrier 20 at this height is effective to impede passage of a land vehicle.
The barrier 20 is any structure effective to stop the travel of a vehicle. Suitable structures for the barrier 20 include cables, webs and bands running either horizontally or vertically. In a preferred embodiment, the barrier 20 is a mesh or net having bands of sufficient strength to avoid breaking when engaging the moving vehicle. Suitable materials for the bands include high tenacity nylon and polyester. A suitable webbing has these bands with a width of from 1 inch to 4 inches and maximum openings of about 12 inches separating the bands.
The webbing forming the barrier 20 is preferably opaque or translucent, or supports an opaque or translucent film, such as a fabric. This obstructs the view of the occupants in the stopped vehicle increasing the safety of the personnel that deployed the vehicle stopping device.
In addition to the breakaway cord 21 and the deceleration cable 22, an elastic cord 36, such as a "bungee cord" is provided. The elastic cord is fastened near the top and bottom of the barrier to hold the webbing taut and open during deployment.
Deployment of the barrier 20 is by extension of the telescoping supports 14, 16. A compressed telescoping support 14 is illustrated in cross-sectional representation in FIG. 5. The support 14 is contained within an enclosure 37, typically manufactured from steel or aluminum, having a frangible or hinged cover 38. The housing 37 is a closed cylinder or other confined shape. A propulsion system 39 is contained adjacent to the closed end of the housing 37. A barrier 40 such as a thin strip of steel separates the propulsion system 39 from a support top plate 41. Activation of the propulsion system 39 communicates at propellant through an aperture 42 extending through barrier 40, driving the support top plate 41 upwards through the cover 38. The support top plate 41 engages the innermost of a plurality of intermeshed cylinders 44 that telescope outward to the second height, D'.
The propulsion system 39 is any suitable force generating composition such as compressed air or pressurized hydraulic fluid. Any gas generating chemical composition, such as a nitrocellulose/nitroglycerine based composition or an ammonium nitrate based composition may be employed.
Preferably, the propulsion system 39 is a rapidly combusting mix that is actuated by a conventional initiator 46. Rapidly combusting mixes are preferred over mechanically, hydraulically or pneumatically actuated systems because the rate of deployment of the telescoping supports is much quicker and the required volume of force generating composition is much less. The initiator 46 is actuated by an electrical signal from leads 48.
The electrical signal may be generated by any suitable signal source such as a manually operated button, a pressure activated sensor embedded in the pathway or a light beam extending across the pathway.
A control system may be used to detect the approaching vehicle and to determine speed and distance. Suitable devices to determine these parameters include pressure sensors embedded in the pathway, electo-optical sensing devices and electromagnetic radiation sensing devices. The control system erects the battier at the appropriate time, based on vehicle speed, to insure the vehicle can not pass over the device and that the driver has inadequate time to take evasive action to avoid the barrier.
The rapidly combusting mix, that is preferably an ammonium nitrate based propellant, when initiated generates a pressure effective to fully deploy the telescoping support 14 in less than 5 seconds. Preferably, the telescoping support 14 is fully deployed in under 1 second and most preferably in from 0.1 to 0.4 seconds.
For a telescoping support having an inside diameter of about 3 inches that extends from a compressed height of about 2 feet to an extended height of up to 8 feet, it is anticipated that about 100 grams of the ammonium nitrate based propellant is required.
The intermeshing cylinders 44 are formed from any material having sufficient strength to withstand forces imposed by a vehicle striking the barrier that is connected to the intermeshing cylinders, such as through connector 50. Suitable materials for the intermeshing cylinders include steel and aluminum.
The telescoping supports 14 are anchored to avoid dislocation when the barrier engages a moving vehicle. The telescoping supports may be embedded in the ground, as illustrated in FIG. 4 and, optionally, are supported by a cement block (not shown) if the vehicle immobilization device is to be permanently installed at a fixed location. If mobility is desired, then a telescoping support 14 as illustrated in FIG. 5 is employed. The telescoping support is anchored through tether lines 52 by explosively driven anchors 54, stakes driven into the ground, buried anchors or other suitable means. Generally, from about 2 to about 8 anchors are effective to prevent dislocation of the telescoping support 14 when the barrier is engaged with a moving land vehicle.
FIGS. 7 through 11 illustrate the operation of the vehicle immobilizer system of the invention. In FIG. 7, a vehicle 56 approaches the device 10 that is in the pre-deployment mode. The sloped surfaces 28 of the barrier enclosure 26 permit passage by non-threatening vehicles.
The approach of a hostile vehicle causes deployment of the barrier 20 as illustrated in FIG. 8. The top surface 30 of the barrier enclosure 26 opens and, optionally, presents tire piercing spikes 32 to the vehicle 56. The telescoping supports 14, 16 rise to the upright position deploying the barrier 20 to a height effective to stop the vehicle 56.
The insert to FIG. 8 shows the attachment of the barrier 20 to the telescoping support 14. Breakaway cords 21 initially fasten the barrier to the telescoping supports so that raising of the supports deploys the barrier. Optionally, elastic cords 38 are attached to the top and the bottom of the barrier 21.
A harness 58 is disposed between the top and bottom elastic cords. A deceleration cable 22 is attached to the barrier 20 through the harness 58 and couples the barrier to the brake system 24.
FIG. 9 illustrates the vehicle 56 impacting the barrier 20. The breakaway cords snap freeing the barrier 20 from the telescoping supports 14, 16. The barrier is held taut against the vehicle 56 by the elastic cord.
FIG. 10 illustrates the barrier 20 fully engaged against the front of the vehicle 56. Elastic cords 36 maintain the barrier against the vehicle. Deceleration cables 22, optionally supported by harness 58, is deployed from the brake system 24. The deceleration cables extend along the side of the vehicle 56 to prevent opening of the vehicle doors and the escape of the occupants. The deceleration cables preferably cross 60 at the rear of the vehicle to prevent escape by going in reverse.
FIG. 11 illustrates the barrier 20 fully engaged against the vehicle 56, obstructing both the door and windshield of the vehicle. The elastic cords 36 have snapped engaging the deceleration cables 22 that are coupled to the braking system 24. The deceleration cables 22 pass through the telescoping supports 14, 16 to one or more brake systems 22. The brake systems absorb the force communicated to the barrier 20 by the vehicle 56 and gradually bring the vehicle to a stop.
The brake system 24 applies a constant rate of mechanical braking to the vehicle 56 at a relatively low deceleration rate, typically between 0.5 g and 3 g and preferably between 1 g and 2 g. "g" is defined as the acceleration of gravity at sea level on the earth.
To stop a vehicle travelling at 60 miles per hour (88 feet/second) with a constant deceleration of 1 g requires a distance of 120 feet. The deceleration cables combined with the braking system therefore have a sufficient length for a stopping distance of at least 60 feet, for 2 g deceleration, and preferably, the effective length is at least 120 feet.
Constant braking is achieved by any suitable means. FIG. 12 illustrates one embodiment where the deceleration cable 22 engages a ripcord 64 anchored to the brake system 24. The ripcord 64 is a plurality of intertwined fibers 66 that require a constant force to unravel. A suitable ripcord is intertwined fibers of nylon or "KEVLAR" (trademark of DuPont, Wilmington, Del.) requiring a constant force of between about 2000 pounds and about 8000 pounds to unravel dependent on the vehicle to be stopped. It is anticipated that about 120, feet of ripcord 64 would be required to bring a vehicle travelling at 60 miles per hour to a stop within desired less than 2 g deceleration.
A second embodiment, illustrated in FIG. 13, is similar to a conventional automobile braking system. The deceleration cable 22 is wound around a shaft 68 of a first metal plate 70. Engagement of the deceleration cable by impact of the barrier by a vehicle (reference arrow 72) causes the shaft to rotate (reference arrow 74) rotating the first metal plate 70. The first metal plate 70 engages a friction plate 76. Friction between the first metal plate 70 and the friction plate 76 provide the braking action. Hydraulic, electric, water brakes and torque converters are also suitable braking systems.
A governor 78 determines the rate of deceleration by varying the friction between the first metal plate 70 and the friction plate 76. Preferably, the deceleration rate does not exceed about 2 g. The friction required to safely decelerate a moped is much less than that required to stop a fully loaded truck.
While telescoping supports are described herein, other rapidly extending structures such as pistons and tractor rockets may also be used. The selection of the support structure is dependent on both the intended application and the size of the vehicle to be immobilized.
While the barrier enclosure is described as a speed bump extending above the surface of a pathway, it is within the scope of the invention for the barrier enclosure to be embedded either in the pathway surface or underground below the pathway surface.
While the barrier and the brake system are illustrated as aligned, they may also be offset.
The entire vehicle immobilization system is transportable in a pick-up truck or similar vehicle. It is believed the entire system could be easily installed and removed by a two person crew.
It is apparent that there has been provided in accordance with this invention a transportable device for immobilizing a land vehicle that fully satisfies the objects, features and advantages set forth hereinabove. While the invention has been described in combination 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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There is disclosed a transportable device and associated method for impeding the motion of a land vehicle travelling along a pathway on a terrain surface. First and second supports are positioned at first and second sides of the pathway, respectively, each capable of being actuated from a compressed condition to an extended condition. A propulsion system is effective to actuate the supports. A barrier extends between the supports at a mean first height that is effective to permit passage of a vehicle when the supports are compressed and supported by each support at a mean second height effective to impede passage of the vehicle when the supports are extended. When the supports are compressed, vehicles pass over the barrier unimpeded. When the supports are extended, the barrier impedes the motion of a vehicle travelling along the pathway. At least one deceleration cable mechanically couples the barrier to a brake system.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to an image processing circuit as well as an image data processing method suited for application to an electrooptic device, wherein video signals obtained by dividing a video signal into a plurality of channels and extending the time axis thereof, so as to maintain a predetermined signal level every unit time, are fed to corresponding data lines at a predetermined timing. Also, it relates to an electrooptic device and electronic equipment which employ such a processing circuit or method.
[0003] 2. Description of Related Art
[0004] A conventional electrooptic device, for example, an active matrix-type liquid-crystal display device, will be explained with reference to FIGS. 11 and 12. First, as shown in FIG. 11, the conventional liquid-crystal display device is constructed of a liquid-crystal display panel 100 , a timing circuit 200 , and a video signal processing circuit 300 . The timing circuit 200 outputs timing signals for use in various portions. The video signal processing circuit 300 can include a D/A converter circuit 301 that converts image data Da supplied by external equipment from a digital signal into an analog signal and outputs the resulting signal as a video signal VID. Further, a phase expansion circuit 302 can be included that expands the received video signal VID of one channel into video signals of N phases (N=6 in the figure) and outputs the resulting video signals. Here, the video signal is expanded into N phases by a sampling circuit so that a time period for which the video signal fed to thin film transistors (TFTs) is applied is lengthened, thereby sufficiently securing a sampling time period for the data signals and a charge/discharge time period for the TFT panel 100 for the data signals.
[0005] In turn, an amplifier/inverter circuit 303 subjects the video signals to polarity inversion under the following conditions and amplifies the inverted signals as required, so as to feed phase-expanded video signals VID 1 -VID 6 to the liquid-crystal display panel 100 . Here, “polarity inversion” signifies alternately inverting the voltage levels of the video signals with respect to a reference potential set at the center potential of the amplitudes of the video signals. Besides, the inversion of the video signals is done when the method of applying the data signal is (1) polarity inversion in scanning line units, (2) polarity inversion in data signal line units, or (3) polarity inversion in pixel units, and the inversion period is set at one horizontal scanning period or one dot clock period.
[0006] The liquid-crystal display panel 100 can be constructed so that an element substrate and a counter substrate are opposed to each other with a gap defined therebetween, and a liquid crystal is enclosed in the gap. Here, each of the element substrate and the counter substrate can be made of a quartz substrate, a hard glass, or the like.
[0007] In the element substrate, a plurality of scanning lines 112 are arrayed and formed in parallel so as to extend in the X-direction in FIG. 12, while a plurality of data lines 114 are formed in parallel so as to extend in the Y-direction orthogonal to the scanning lines 112 . Here, the data lines 114 are divided into blocks each consisting of six lines, and the blocks are termed “blocks B 1 -Bm”. For brevity of the ensuing explanation, when referring to the data lines in general, they will be designated by the reference numeral 114 , but when referring to specified ones of the data lines 114 , they will be designated by reference numerals 114 a - 114 f.
[0008] At the intersection points between the scanning lines 112 and the data lines 114 , TFTs 116 are connected as switching elements, by way of example. More specifically, the gate electrodes of the TFTs 116 are connected to the scanning lines 112 , while the source electrodes thereof are connected to the data lines 114 , and the drain electrodes thereof are connected to pixel electrodes 118 . Individual pixels are configured of the pixel electrodes 118 , a common electrode formed on the counter substrate, and the liquid crystal sandwiched in between both the electrodes, and they are arrayed in the shape of a matrix at the intersection points between the scanning lines 112 and the data lines 114 . Incidentally, retention capacitors (not shown) are further formed in a state where they are respectively connected to the pixel electrodes 118 .
[0009] Meanwhile, a scanning line driver circuit 120 can be formed on the element substrate, and the scanning line driver circuit 120 outputs pulse-like scanning signals to the respective scanning lines 112 in succession on the basis of a clock signal CLY, the inverted clock signal CLYinv thereof, a transfer start pulse DY, etc. delivered from the timing circuit 200 . More specifically, the scanning line driver circuit 120 successively shifts the transfer start pulse DY fed at the beginning of a vertical scanning period in accordance with the clock signal CLY and the inverted clock signal CLYinv, and it outputs the resulting signals as scanning line signals, to thereby successively select the respective scanning lines 112 .
[0010] On the other hand, a sampling circuit 130 includes a sampling switch 131 at one end of each of the data lines 114 . The switches 131 can be made of TFTs which are also formed on the element substrate, and the source electrodes of these switches 131 are fed with the corresponding video signals VID 1 -VID 6 through video signal feed lines L 1 -L 6 . Besides, the gate electrodes of the six switches 131 connected to the data lines 114 a - 114 f of the block B 1 are connected to a signal line which is fed with a sampling signal S 1 , and those of the six switches 131 connected to the data lines 114 a - 114 f of the block B 2 are connected to a signal line which is fed with a sampling signal S 2 . Likewise, the gate electrodes of the six switches 131 connected to the data lines 114 a - 114 f of the block Bm are connected to a signal line which is fed with a sampling signal Sm. Here, each of the sampling signals S 1 -Sm is a signal for sampling the video signals VID 1 -VID 6 every block within a horizontal effective display period.
[0011] A shift register circuit 140 is also formed on the element substrate, and the shift register 140 outputs the sampling signals S 1 -Sm in succession on the basis of a clock signal CLX, the inverted clock signal CLXinv thereof, a transfer start pulse DX, etc. delivered from the timing circuit 200 . More specifically, the shift register circuit 140 successively shifts the transfer start pulse DX fed at the beginning of the horizontal scanning period in accordance with the clock signal CLX and the inverted clock signal CLXinv, and it successively outputs the resulting signals as the sampling signals S 1 -Sm.
[0012] In such a construction, when the sampling signal S 1 is outputted, the video signals VID 1 -VID 6 are respectively sampled by the six data lines 114 a - 114 f belonging to the block B 1 , and they are respectively written into the six pixels associated with the selected scanning lines at the current time by the corresponding TFTs 116 .
[0013] Thereafter, when the sampling signal S 2 is outputted, the video signals VID 1 -VID 6 are respectively sampled by the six data lines 114 a - 114 f belonging to the block B 2 , on this occasion, and they are respectively written into the six pixels associated with the selected scanning lines at that time by the corresponding TFTs 116 .
[0014] Likewise, when the sampling signals S 3 , S 4 , . . . and Sm are successively outputted, the video signals VID 1 -VID 6 are respectively sampled by the six data lines 114 a - 114 f belonging to the blocks B 3 , B 4 , . . . and Bm, and they are respectively written into the six pixels associated with the selected scanning lines at those times. Then, the next scanning lines are subsequently selected, and similar write operations are repeatedly executed in the blocks B 1 -Bm.
[0015] With the above driving system, the number of stages of the shift register circuit 140 for driving and controlling the switches 131 in the sampling circuit 130 is reduced to ⅙ as compared with the number of stages in a system in which the respective data lines are driven in point sequence. Moreover, the frequencies of the clock signal CLX and the inverted clock signal CLXinv to be fed to the shift register circuit 140 may be as small as ⅙, so that a lower power dissipation can be attained along with a reduction in the number of stages.
[0016] However, in the system in which a video signal of one channel is subjected to phase expansion into a plurality of channels so as to drive a liquid-crystal display panel by employing multi-channel video signals, there can be a problem in that gradations to be displayed deviating from the desired ones are displayed in block units (hereinbelow, the phenomenon shall be termed “block ghost”).
[0017] By way of example, consider a liquid-crystal display panel which operates in a normally-white mode, and one screen of which is constituted by blocks B 1 -B 7 , as shown in FIG. 13A. It is assumed that black is displayed in the blocks B 1 -B 3 and in the area b 41 of the block B 4 , as shown in FIG. 13B, while a gray level is displayed in the area b 42 of the block B 4 and in the blocks B 5 , B 6 and B 7 . Then, the area b 42 becomes somewhat brighter than the gray level, and the following block B 5 becomes somewhat darker than the gray level.
[0018] As a result of repeated experiments and studies on such block ghosts, it has been found that the major factors of the block ghost are the two factors stated below.
[0019] In the liquid-crystal display panel 100 shown in FIG. 12, an equivalent circuit concerning the i-th block Bi is as shown in FIG. 14. Referring to FIG. 14, letter R indicates the equivalent resistance of the counter electrode (common electrode). Since the liquid crystal is sandwiched between the video signal feed lines L 1 -L 6 and the counter electrode, parasitic capacitances appear. Reference characters Cxa-Cxf denote the parasitic capacitances as equivalent capacitances. Further, reference characters 131 a - 131 f denote the sampling switches 131 which correspond to the respective video signal feed lines L 1 -L 6 . In addition, reference characters Cya-Cyf denote the parasitic capacitances of the data lines 114 a - 114 f (chiefly appearing between these data lines and the counter electrode) and the capacitances of pixel capacitors as equivalent capacitances.
[0020] The first factor consists in the point that differentiator circuits are formed by the equivalent capacitances Cxa-Cxf and the resistance R, so when the video signals VID 1 -VID 6 are inputted to the liquid-crystal display panel 100 , a waveform corresponding to the magnitude of the voltage changes of the video signals VID 1 -VID 6 is generated on the counter electrode.
[0021] The second factor is that voltage change of the counter electrode is due to charging/discharging in the case where the block Bi is selected. More specifically, when the block Bi is selected to turn ON the switches 131 a - 131 f , the equivalent capacitances Cya-Cyf are charged/discharged from an initial voltage Vs (the voltage at the nodes between the equivalent capacitances Cya-Cyf and the switches 113 a - 113 f at the start of the selection time period of the block Bi) to the voltages of the video signals VID 1 -VID 6 . The second factor results from a differential waveform being generated on the counter electrode by charging/discharging currents on this occasion.
[0022] The voltage distortions of the differential waveforms caused by the first and second factors appear at the start of the selection time period of the block Bi, and attenuate over time. Letting Ve denote an error voltage which remains on the counter electrode at the end of the selection time period of the block Bi, non-uniformity in display occurs unless Ve is set to zero. The reason is that the switches 113 a - 113 f are turned OFF at the end of the selection time period, so voltages affected by the error voltage Ve are held in the pixel capacitors.
[0023] A first error voltage Ve 1 attributable to the first factor is given by the following equation (1), where α denotes a constant, and V k,i denotes the video signal which is to be fed to the k-th data line in the i-th block:
Ve1 = α ∑ k = 1 6 ( V k , t - V k , i - 1 ) ( 1 )
[0024] A second error voltage Ve 2 attributable to the second factor is given by the following equation (2), where β denotes a constant:
Ve2 = β ∑ k = 1 6 ( V k , 1 - Vs ) ( 2 )
[0025] Accordingly, the error voltage Ve which is the total of the error voltages Ve 1 and Ve 2 is given by the following equation (3):
Ve = α ∑ k = 1 6 ( V k , i - V k , i - 1 ) + β ∑ k = 1 6 ( V k , i - Vs ) ( 3 )
[0026] Using equations (1)-(3), luminance changes in the blocks B 3 to B 5 shown in FIG. 13B will be studied. Here, as shown in FIG. 13B, it is assumed that a black level Vb is fed to the four left-hand data lines (in the area b 41 ) among the six data lines 114 a - 114 f constituting the block B 4 , that a gray level Vc is fed to the two right-hand data lines (in the area b 42 ), and that the initial voltage Vs agrees with the gray level Vc.
[0027] First, consider the change of the luminance level of the block B 3 at I=3. As shown in FIG. 13A, the block B 2 directly preceding the block B 3 displays black similarly to the block B 3 . Therefore, both the terms V k,i and V k,i−1 in equation (1) become the black level Vb, and Ve 1 =0 holds. Since the initial voltage Vs agrees with the gray level Vc, Ve 2 =6β(Vb−Vc)>0 holds. Accordingly, the error voltage Ve becomes positive, and the block B 3 brightens. Human vision, however, cannot substantially detect a luminance change for black though it can detect even a slight luminance change for a gray level. Therefore, a person would hardly notice that the block B 3 has become brighter.
[0028] Secondly, regarding the block B 4 , black is displayed in the ⅔ area b 41 , and a gray level is displayed in the remaining ⅓ area b 42 . Therefore, Ve 1 =−2α(Vb−Vc)<0 and Ve 2 =4β(Vb−Vc)>0 hold. Whether the error voltage Ve takes a positive value or a negative value, depends upon the values of the constants α and β. In general, the values of the equivalent capacitances Cya-Cyf are greater than those of the equivalent capacitances Cxa-Cxf, so that β>α holds in many cases. Accordingly, the error voltage Ve usually becomes positive, and the entire block B 4 brightens. Owing to the visual characteristic stated above, however, a person can detect that the area b 42 displaying the gray level has brightened, though they hardly notices that the luminance of the area b 41 displaying black has increased.
[0029] Thirdly, since the gray level is displayed in the block B 5 , Ve 1 =−4α(Vb−Vc)<0 and Ve 2 =0 hold, and the error voltage Ve takes a negative value. Therefore, the block B 5 darkens.
SUMMARY OF THE INVENTION
[0030] The present invention has been made in view of the above circumstances, and has one object to strongly enhance the display quality in such a way that, in a case where a gray level to be displayed changes midway in a block, block ghosting in the remaining area (for example, b 42 ) of the pertinent block and in the next block (for example, B 5 ) are cancelled.
[0031] In order to accomplish the object, an image processing circuit according to a first aspect of the present invention is an image processing circuit for use in an electrooptic device having a plurality of scanning lines, a plurality of data lines, switching elements which are respectively disposed in correspondence with intersections between the scanning lines and the data lines, and pixel electrodes which are electrically connected to the corresponding switching elements. The image processing circuit can include a delay circuit which delays externally supplied image data by a unit time so as to output delayed image data, a first correction-data generation circuit for generating first correction data on the basis of data which has been obtained by averaging a difference between the image data and the delayed image data every unit time, a second correction-data generation circuit for generating second correction data on the basis of data which has been obtained by averaging a difference between the image data and predetermined reference data every unit time, a correction circuit for generating corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data, and a phase expansion circuit which divides the corrected image data into a plurality of phase-expanded video signals and which feeds the phase-expanded video signals to the plurality of data lines.
[0032] In the electrooptic device to which the invention is applied, an image is displayed on the basis of phase-expanded video signals divided into a plurality of channels. In this regard, parasitic capacitances occur in video signal feed lines which lead to the corresponding data lines. Further, parasitic capacitances also occur in the data lines themselves, and pixel capacitors are disposed. Moreover, a distributed resistance exists in a counter electrode. Therefore, differentiator circuits are equivalently formed between the video signal feed lines and the counter electrode, while differentiator circuits are equivalently formed between the data lines and the counter electrode. Accordingly, when the signal level of a video signal which is fed to the electrooptic device changes, a first error voltage is induced in the counter electrode by the differentiator circuit formed between the video signal feed line and the counter electrode. Moreover, when a certain one of the data lines is selected, charging/discharging takes place, so that the second error voltage of the counter electrode changes. Ghosting can be caused by these factors.
[0033] According to the first aspect of present invention, the first correction-data generation circuit can average the first difference data every unit time, thereby generating the first correction data, which corresponds to the first error voltage. The second correction-data generation means averages the second difference data every unit time, thereby generating the second correction data, which corresponds to the second error voltage. That is, the first and second correction data correspond to the voltage changes of the counter electrode as predicted. The corrected image data is generated by correcting the delayed image data on the basis of the first and second correction data, so that even when the first and second error voltages occur in the counter electrode, they can be cancelled by generating the video signals on the basis of the corrected image data. As a result, the block ghosting can be greatly reduced and the quality of a displayed image can be strongly enhanced.
[0034] In the first aspect of performance of the present invention, the first correction-data generation circuit can preferably include a first subtracter circuit which calculates the difference between the image data and the delayed image data as first difference data, a first averaging circuit which generates first average data obtained by averaging the first difference data every unit time, and a first coefficient circuit which generates the first correction data by multiplying the first average data by a first coefficient.
[0035] The first averaging circuit may preferably include an accumulator circuit which accumulates the first difference data every unit time, and a divider circuit which divides the accumulated result by the number of the video signals divided the corrected image data into the plurality of phase-expanded video signals.
[0036] In the first aspect of the present invention, the second correction-data generation circuit can include a second subtracter circuit which calculates the difference between the image data and the reference data as second difference data, a second averaging circuit which generates second average data obtained by averaging the second difference data every unit time, and a second coefficient circuit which generates the second correction data by multiplying the second average data by a second coefficient.
[0037] The second averaging circuit can include an accumulator circuit which accumulates the second difference data every unit time, and a divider circuit which divides a result of the accumulation by the number of the video signals divided the corrected image data into the plurality of phase-expanded video signals.
[0038] Accordingly, the accumulated results are divided by the number of the divided video signals (the number of the phase-expanded video signals), so that the first and second difference data averaged in each block can be calculated.
[0039] Preferably, the reference data corresponds to an initial voltage which is applied to pixel capacitors including the pixel electrodes, a counter electrode held opposite to the pixel electrodes, and an electrooptic material.
[0040] Alternatively, the reference data may be a precharge voltage which is applied to pixel capacitors including the pixel electrodes, a counter electrode held in opposition to the pixel electrodes, and an electrooptic material.
[0041] Since the second error voltage described above is due to the charging/discharging, the changes of the voltages of the data lines and the pixel capacitors become problematic. Therefore, the initial voltage or the precharge voltage can be employed as the reference data. In the actual electrooptic device, however, the optimum value of the reference data can deviate from the initial or precharge voltage on account of various factors, and hence, the reference data may be essentially set so as to visually minimize the block ghosting.
[0042] The electrooptic device can further include a plurality of switching elements which sample the respective phase-expanded video signals in accordance with sampling signals and which feed them to the corresponding data lines, and video signal feed lines which feed the respective video signals to the corresponding switching elements. The first coefficient of the first coefficient circuit may preferably be determined on the basis of, at least, parasitic capacitance components due to the respective video signal feed lines and a resistance component of a counter electrode held opposite to the pixel electrodes. Thus, the ghosting attributable to the first error voltage can be effectively cancelled.
[0043] The second coefficient of the second coefficient circuit may preferably be determined on the basis of, at least, parasitic capacitance components due to the respective data lines and a resistance component of a counter electrode held opposite to the pixel electrodes. Thus, the ghosting attributable to the second error voltage can be effectively cancelled.
[0044] An image processing circuit according to a second aspect of the present invention can include a delay circuit which delays externally supplied image data by a unit time so as to output delayed image data, a first correction-data generation circuit that generates first correction data on the basis of data which has been obtained by averaging a difference between the image data and the delayed image data every unit time, a second correction-data generation circuit that generates second correction data on the basis of data which has been obtained by averaging a difference between the image data and predetermined reference data every unit time and a correction circuit that generates corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data.
[0045] According to the second aspect of the present invention, the first correction-data generation circuit averages the first difference data every unit time, thereby generating the first correction data, which corresponds to a first error voltage. The second correction-data generation circuit averages the second difference data every unit time, thereby generating the second correction data, which corresponds to a second error voltage. That is, the first and second correction data correspond to the voltage changes of a counter electrode as predicted. The corrected image data is generated by correcting the delayed image data on the basis of the first and second correction data, so that even when the first and second error voltages occur in the counter electrode, they can be cancelled by generating video signals on the basis of the corrected image data. As a result, block ghosting can be substantially reduced and the quality of the displayed image can be strongly enhanced.
[0046] An electrooptic device according to a third aspect of the present invention can include a plurality of scanning lines, a plurality of data lines, switching elements which are respectively disposed in correspondence with intersections between the scanning lines and the data lines, pixel electrodes which are respectively electrically connected to the switching elements, and a delay circuit which delays externally supplied image data by a unit time so as to output delayed image data. The device can further include a first correction-data generation circuit for generating first correction data on the basis of data which has been obtained by averaging a difference between the image data and the delayed image data every unit time, a second correction-data generation circuit for generating second correction data on the basis of data which has been obtained by averaging a difference between the image data and predetermined reference data every unit time, a correction circuit for generating corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data, and a phase expansion circuit which divides the corrected image data into a plurality of phase-expanded video signals and which feeds the phase-expanded video signals to the plurality of data lines.
[0047] According to the electrooptic device, block ghosting can be substantially reduced and quality of the displayed image can be strongly enhanced.
[0048] Preferably, the above electrooptic device may further include a data line driver circuit which generates sampling signals in succession; and a sampling circuit which samples the phase-expanded video signals on the basis of the sampling signals and feeds the sampled signals to the corresponding data lines.
[0049] According to this electrooptic device, the quality of the display image can be strongly enhanced, and a time period for which the video signals are fed to the data lines can be lengthened.
[0050] Electronic equipment according to the present invention is characterized by including the electrooptic device described above, and includes, for example, a video projector, a notebook-type personal computer, and a mobile telephone.
[0051] A a first image data processing method according to a fourth aspect of the present invention is an image data processing method for use in an electrooptic device wherein video signals are fed to a plurality of data lines. The method includes the steps of generating delayed image data by delaying externally supplied image data by a unit time, generating a difference between the image data and the delayed image data as first difference data, generating first average data by averaging the first difference data every unit time, generating first correction data by multiplying the first average data by a first coefficient, generating a difference between the image data and predetermined reference data as second difference data, generating second average data by averaging the second difference data every unit time, generating second correction data by multiplying the second average data by a second coefficient, generating corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data, and dividing the corrected image data into the plurality of phase-expanded video signals, and then feeding said video signals to the plurality of data lines.
[0052] According to this image data processing method, the first correction data corresponds to a first error voltage, and the second correction data corresponds to a second error voltage, so that the first and second correction data correspond to the voltage changes of a counter electrode as predicted. The corrected image data is generated by correcting the delayed image data on the basis of the first and second correction data, so that even when the first and second error voltages occur in the counter electrode, they can be cancelled by generating the video signals on the basis of the corrected image data. As a result, block ghosting can be substantially reduced and the quality of the displayed image can be strongly enhanced.
[0053] An image data processing method according to a fifth aspect of the present invention can include the steps of generating delayed image data by delaying externally supplied image data by a unit time, generating a difference between the image data and the delayed image data as first difference data, generating first average data by averaging the first difference data every unit time, generating first correction data by multiplying the first average data by a first coefficient, generating a difference between the image data and predetermined reference data as second difference data, generating second average data by averaging the second difference data every unit time, generating second correction data by multiplying the second average data by a second coefficient, and generating corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data.
[0054] According to this image data processing method, block ghosting can be substantially reduced and the quality of the displayed image can be greatly enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] The invention is described in detail with reference to the following Figures, wherein like numerals reference like elements, and wherein:
[0056] [0056]FIG. 1 is an exemplary block diagram showing the overall construction of a liquid-crystal display device in accordance with the present invention;
[0057] [0057]FIG. 2 is a block diagram showing the construction of a deghosting circuit in the liquid-crystal display device;
[0058] [0058]FIG. 3 is a block diagram showing the construction of a phase expansion circuit in the liquid-crystal display device;
[0059] [0059]FIG. 4 is a timing chart showing the operation of a first correction unit of the deghosting circuit;
[0060] [0060]FIG. 5 is a timing chart showing the operation of a second correction unit of the deghosting circuit;
[0061] [0061]FIG. 6 is a timing chart showing the operation of the phase expansion circuit in the liquid-crystal display device;
[0062] [0062]FIG. 7 is a timing chart of phase-expanded video signals in the case of phase-expanding image data without employing the deghosting circuit, and corrected image data generated by employing the deghosting circuit;
[0063] [0063]FIG. 8 is a sectional view showing the construction of a projector which is an example of electronic equipment to which the liquid-crystal display device is applied;
[0064] [0064]FIG. 9 is a perspective view showing the construction of a personal computer which is an example of electronic equipment to which the liquid-crystal display device is applied;
[0065] [0065]FIG. 10 is a perspective view showing the construction of a portable telephone which is an example of electronic equipment to which the liquid-crystal display device is applied;
[0066] [0066]FIG. 11 is a block diagram showing the overall construction of a conventional liquid-crystal display device;
[0067] [0067]FIG. 12 is a connection diagram showing the electrical construction of a liquid-crystal display panel in the conventional liquid-crystal display device;
[0068] [0068]FIGS. 13A and 13B are explanatory diagrams showing an example of ghosting; and
[0069] [0069]FIG. 14 is a circuit diagram showing an equivalent circuit in a given block.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0070] First, an active matrix-type liquid-crystal display device will be described as an example of an electrooptic device according to the present invention.
[0071] [0071]FIG. 1 is a block diagram showing the overall construction of the liquid-crystal display device. The liquid-crystal display device in this embodiment is constructed similarly to the conventional liquid-crystal display device shown in FIG. 11, except that, in a video signal processing circuit 300 A, a deghosting circuit 304 is included at a stage preceding a D/A converter 301 . The image data Da in this example can be a data string which has 8 bits in a parallel and whose sampling period is equal to the period of a dot clock signal DCLK, and it is supplied by external equipment (not shown).
[0072] The deghosting circuit 304 predicts block ghost components caused by the first and second factors explained above, and corrects the image data Da so as to cancel the predicted block ghost components, thereby generating corrected image data Dout.
[0073] A phase expansion circuit 302 subjects a video signal VID obtained by D/A-converting the corrected image data Dout, to serial-to-parallel conversion, thereby generating phase-expanded video signals VID 1 -VID 6 expanded into six phases. More specifically, the phase expansion circuit 302 samples-and-holds the video signal VID on the basis of a sample-and-hold pulse SS and 6-phase sample-and-hold pulses SP 1 -SP 6 , which become active every six cycles of the dot clock signal DCLK, so as to extend the time axis of the video signal VID by a factor of six, and it divides the extended video signal into six channels, thereby generating the phase-expanded video signals VID 1 -VID 6 .
[0074] The phase-expanded video signals VID 1 -VID 6 are generated on the basis of the video signal VID obtained by D/A-converting the corrected image data Dout in synchronization with the dot clock signal DCLK. Therefore, if the value of the original corrected image data Dout changes every dot clock cycle, the respective phase-expanded video signals VID 1 -VID 6 change every six dot clock cycles. Accordingly, the phase-expanded video signals VID 1 -VID 6 become signals which change with one unit time being a time period that is determined by the product between the number of expanded phases (the number of divided channels) and one cycle of the dot clock signal DCLK.
[0075] A liquid-crystal display panel 100 is the same as that employed in the conventional liquid-crystal display device shown in FIG. 12, and therefore a description is omitted here.
[0076] [0076]FIG. 2 is a detailed circuit diagram of the deghosting circuit 304 . As shown, the deghosting circuit 304 is constructed of a delay unit Ud, a first correction unit Uh 1 , a second correction unit Uh 2 , and a subtracter circuit 45 .
[0077] First, the delay unit Ud is constructed by connecting six latch circuits LAT 1 -LAT 6 in series, and it delays the image data Da by a predetermined time period so as to output image data Db. Here, the latch circuits LAT 1 -LAT 6 latch the 8-bit input data Da on the basis of the dot clock signal DCLK.
[0078] The dot clock signal DCLK is the master clock of the liquid-crystal display device, and is generated in the timing circuit 200 . The timing circuit 200 divides the frequency of the dot clock signal DCLK so as to generate a clock signal CLX for driving the data line driver circuit of the liquid-crystal display panel 100 , and a clock signal CLY for driving the scanning line driver circuit thereof. In this example, phase expansion into six phases is carried out in the phase expansion circuit 302 . Therefore, the clock signal CLX is generated by dividing the frequency of the dot clock signal DCLK by 6.
[0079] Since the delay unit Ud is constructed of the series connection consisting of the six latch circuits LAT 1 -LAT 6 which are driven by the dot clock signal DCLK, the image data Db becomes data delayed by six dot clock periods relative to the image data Da.
[0080] Meanwhile, as described above, the phase-expanded video signals VID 1 -VID 6 change with one unit time being the time period which is determined by the product between the number of expanded phases (the number of channels into which the video signal VID is divided) and one period of the dot clock signal DCLK. In this example, one unit time becomes the six dot periods, which agree with the delay time of the delay unit Ud. In other words, the delay unit Ud generates the image data Db by delaying the image data Da for the time period which corresponds to one unit time of the phase-expanded video signals VID 1 -VID 6 (the selection time period of a certain block) obtained by the phase expansion (serial-to-parallel conversion). Here, when the image data Da is current data, the image data Db is previous data one unit time before the current data one unit time.
[0081] Next, the first correction unit Uh 1 includes a first subtracter circuit 41 , a first averaging circuit 42 , a first coefficient circuit 43 , and a latch circuit 44 , and it generates first correction data Dh 1 corresponding to the first error voltage Ve 1 explained before. The first subtracter circuit 41 subtracts the image data Db (previous) from the image data Da (current), thereby generating first difference data Dx.
[0082] Subsequently, the first averaging circuit 42 averages the first difference data Dx for each block, thereby generating first average data Dw 1 . The averaging circuit 42 has an adder circuit 421 and a latch circuit 422 . The latch circuit 422 latches the output signal of the adder circuit 421 on the basis of the dot clock signal DCLK. The first difference data Dx is fed to one input terminal of the adder circuit 421 , while the output data of the latch circuit 422 is fed back to the other input terminal thereof. Accordingly, the adder circuit 421 and the latch circuit 422 function as an accumulator circuit. A reset signal RS of six dot clock cycles is fed to the reset terminal R of the latch circuit 422 . Therefore, the first difference data Dx is reset and is accumulated every unit time.
[0083] The first averaging circuit 42 further includes a divider circuit 423 and a latch circuit 424 . The divider circuit 423 divides data obtained by accumulating the first difference data Dx in block units by “6” (the number of expanded phases). The latch circuit 424 latches the output data of the divider circuit 423 in accordance with a block clock signal BCLK which becomes active every unit time, and it outputs the latched data as the first average data Dw 1 . Incidentally, the block clock signal BCLK is generated by the timing circuit 200 shown in FIG. 1.
[0084] Subsequently, the first coefficient circuit 43 includes a multiplier unit, and first coefficient circuit 42 multiplies the first average data Dw 1 by a first coefficient K 1 and outputs the resulting product. The latch circuit 44 is used for time adjustment, and latch circuit yy latches the output data of the coefficient circuit 43 and outputs the latched data as the first correction data Dh 1 .
[0085] In this manner, in the first correction unit Uh 1 , the image data Db of the directly preceding block is subtracted from the image data Da of the current block, the subtracted result is integrated in block units, the integrated result is divided by the number of expanded phases (the number of divided channels), and the divided result is multiplied by the first coefficient K 1 , whereby the first correction data Dh 1 is obtained. Accordingly, when K 1 /6=α is set, the first correction data Dh 1 agrees with the first error voltage Ve 1 explained before. Here, the first coefficient K 1 should desirably be determined on the basis of, at least, the parasitic capacitance components occurring in the respective video signal feed lines L 1 -L 6 and the resistance component of the counter electrode.
[0086] Next, the second correction unit Uh 2 includes a second subtracter circuit 51 , a second averaging circuit 52 , a second coefficient circuit 53 , and a latch circuit 54 , and it generates second correction data Dh 2 corresponding to the second error voltage Ve 2 explained before.
[0087] The second subtracter circuit 51 subtracts predetermined reference data Dref from the image data Da, thereby generating second difference data Dy. Here, the reference data Dref can be experimentally determined so as to minimize the block ghosting.
[0088] As the reference data Dref, it is desirable to select the initial voltage Vs which was written to and held in the pixel capacitors of the pixels belonging to a certain block when the block was selected. The reason for this is that, as explained before, the second factor arises when the initial voltages Vs of the pixel capacitors change, to the voltages of the video signals VID 1 -VID 6 .
[0089] Meanwhile, the liquid-crystal display panel 100 is driven by an A.C. drive method so as not to apply a D.C. voltage to the liquid crystal. Therefore, at a certain pixel, the polarity of a voltage which is applied to the liquid crystal needs to be inverted with respect to the voltage of the counter electrode as a center voltage between even-numbered fields and odd-numbered fields. An image has a high correlation between the fields, so that when black is displayed in the even-numbered field for the certain pixel, it is often displayed in the succeeding odd-numbered field. In this case, the voltage which is applied to the pixel capacitor needs to be greatly changed between the fields. Since, however, the data line 114 and the pixel capacitor are capacitive loads, the voltage of the pixel capacitor sometimes fails to be changed to a target voltage during the selection time period of the block. In this regard, a predetermined voltage is sometimes applied to the pixel capacitors beforehand in a vertical blanking period, a horizontal blanking period, or the like. This voltage is called a “precharge voltage” and is set to, for example, a gray level. In a drive method wherein the precharge voltage is applied, this precharge voltage acts as the initial voltage Vs, and it may well be employed as the reference data Dref.
[0090] Subsequently, similarly to the first averaging circuit 42 , the second averaging circuit 52 includes an adder circuit 521 and a latch circuit 522 which perform accumulation every block, a divider circuit 523 , and a latch circuit 524 . The second averaging circuit 52 averages second difference data Dy for each block, thereby generating second average data Dw 2 .
[0091] Further, the second coefficient circuit 53 includes a multiplier unit, and it multiplies the second average data Dw 2 by a second coefficient K 2 and outputs the resulting product. The latch circuit 54 is used for time adjustment, and it latches the output data of the second coefficient circuit 53 and outputs the latched data as the second correction data Dh 2 .
[0092] In this manner, in the second correction unit Uh 2 , the reference data Dref is subtracted from the image data Da of the current block, the subtracted result is integrated in block units, the integrated result is divided by the number of expanded phases (the number of divided channels), and the divided result is multiplied by the second coefficient K 2 , whereby the second correction data Dh 2 is obtained. Accordingly, when K 2 /6=β is set, the second correction data Dh 2 agrees with the second error voltage Ve 2 described before. Here, the second coefficient K 2 should desirably be determined on the basis of, at least, the parasitic capacitance components due to the respective data lines 114 a - 114 f and the resistance component of the counter electrode. According to the second correction unit Uh 2 , in a case, by way of example, where luminance has changed from black to a gray level midway within a certain block, the value of the second correction data Dh 2 can be adjusted in accordance with the black area occupied in the pertinent block.
[0093] Next, the subtracter circuit 45 subtracts the first correction data Dh 1 and the second correction data Dh 2 from the image data Db and outputs the resulting difference as the corrected image data Dout. Since the first correction data Dh 1 and second correction data Dh 2 correspond to the respective error voltages Ve 1 and Ve 2 as explained before, the subtraction thereof from the image data Db permits the generation of the corrected image data Dout in which reverse block ghost components are contained in the image data Db. Thus, the block ghosting caused by the first and second factors can be cancelled.
[0094] The reason why the image data Da before the phase expansion is subjected to correction in this embodiment is as follows. Since the signals after the phase expansion have been divided into the six channels, when deghosting circuits are disposed for the respective channels, the circuit arrangement becomes complicated. In contrast, when the image data Da is subjected to correction, the ghosting can be cancelled by the circuit for one channel. Therefore, according to this embodiment, the ghosting can be effectively cancelled by asing a simple construction.
[0095] Next, the phase expansion circuit 302 will be described. FIG. 3 is a block diagram showing the main construction of the phase expansion circuit 302 . As shown in the figure, the phase expansion circuit 302 has a first sample-and-hold unit USa which includes sample-and-hold circuits SHa 1 -SHa 6 , and a sample-and-hold unit USb which includes sample-and-hold circuits SHb 1 -SHb 6 .
[0096] The sample-and-hold circuits SHa 1 -SHa 6 of the first sample-and-hold unit USa sample-and-hold the video signal VID on the basis of the sample-and-hold pulses SP 1 -SP 6 fed from the timing circuit 200 , so as to generate signals vid 1 -vid 6 , respectively. Here, one period of all the sample-and-hold pulses SP 1 -SP 6 is six times larger than the period of the dot clock signal DCLK, and the phases of the adjacent ones of these pulses are shifted by one period of the dot clock signal DCLK. Accordingly, the time axis of all the signals vid 1 -vid 6 is extended by a factor of six relative to that of the video signal VID, and the phases of the signals vid 1 -vid 6 are successively shifted by a dot clock signal period.
[0097] Next, the sample-and-hold circuits SHb 1 -SHb 6 of the second sample-and-hold unit USb sample-and-hold the signals vid 1 -vid 6 on the basis of the sample-and-hold pulse SS fed from the timing circuit 200 , so as to output the resulting signals as the phase-expanded video signals VID 1 -VID 6 through corresponding buffer circuits (not shown). The sample-and-hold pulse SS has a period of one unit time. Accordingly, the signals vid 1 -vid 6 are phased at a timing at which the sample-and-hold pulse SS becomes active, so that in-phase phase-expanded video signals VID 1 -VID 6 are generated.
[0098] Now, the operation of the liquid-crystal display device will be described. First, the operation from after the input of the image data Da until the corrected image data Dout is generated by the deghosting circuit 304 will be explained. FIG. 4 is a timing chart for explaining the operation of the deghosting circuit 304 . In this figure, suffix X in symbol DX,Y denotes the number of the data lines 114 within one block in the scanning direction of the block, while suffix Y denotes the number of blocks. By way of example, data D 1 ,n+1 corresponds to the first data line 114 a in a block, and the pertinent block is the (n+1)-th block.
[0099] The operation of the first correction unit Uh 1 will be explained. When the image data Da is fed to the deghosting circuit 304 , the delay unit Ud delays the image data Da by one unit time (six dot clock cycles) and outputs the delayed data as the image data Db.
[0100] Thus, the image data Db which precedes the image data Da by one unit time is obtained. By way of example, for a time period Tx indicated in FIG. 4, the image data Da is data D 2 ,n, which corresponds to the data line 114 b of the block Bn. On the other hand, the image data Db is data D 2 ,n−1, which corresponds to the data line 114 b of the block Bn−1. The data line 114 b of each of the blocks is fed with the video signal VID 2 through the video signal feed line L 2 . That is, both the image data Da and the image data Db in the pertinent time period Tx correspond to the video signal VID 2 which is fed through the video signal feed line L 2 . Moreover, since the image data Da and the image data Db correspond to adjacent blocks, they are data before and after the signal level of the video signal VID 2 is changed over.
[0101] When the image data Da and Db are fed to the first subtracter circuit 41 , this circuit 41 subtracts the image data Db (previous: one block before) from the image data Da (current), thereby generating the first difference data Dx. By way of example, in the time period Tx indicated in the figure, the image data Da and the image data Db are the data “D 2 ,n” and “D 2 ,n−1”, respectively, and hence, the first difference data Dx becomes data “D 2 ,n−D 2 ,n−1”.
[0102] As shown in FIG. 14, the video signal feed lines L 1 -L 6 are capacitively coupled. Therefore, when the video signal VID which is applied to any of the video signal feed lines L 1 -L 6 changes, the first error voltage Ve 1 is induced in the counter electrode, and the whole pertinent block is affected. Since the whole block is affected by the change of the video signal fed to a certain video signal feed line, the first averaging circuit 42 is used in order to reflect this change in the other video signals.
[0103] Since the first difference data Dx are accumulated by the adder circuit 421 and the latch circuit 422 included in the first averaging circuit 42 , the output data of the latch circuit 422 corresponding to the last timing within each block becomes the sum of the first difference data Dx accumulated in the pertinent block. By way of example, in a time period from a time t 10 to a time t 12 indicated in FIG. 4, the output data of the latch circuit 422 becomes Dx 1 ,n+Dx 2 ,n+ +Dx 6 ,n.
[0104] The output data of the latch circuit 422 is divided by the divider circuit 423 , and the latch circuit 424 latches the divided result on the basis of the block clock signal BCLK. Therefore, the latch circuit 424 generates the first average data Dw 1 before the output data of the latch circuit 422 is reset. In the illustrated example, when the block clock signal BCLK rises from a low level to a high level at a time t 11 , the latch circuit 424 generates the first average data Dw 1 in synchronization with the rising edge of the signal BCLK. Thereafter, when the time t 12 is reached, the reset signal RS becomes active (high level), and hence, the latch circuit 422 has its output data reset to prepare for the accumulation of the first difference data Dx of the next block.
[0105] Further, when the first average data Dw 1 is fed to the coefficient circuit 43 , it is multiplied by the first coefficient K 1 . The resulting data, however, is out of phase with the image data Db. Therefore, the latch circuit 44 latches the output data of the coefficient circuit 43 in accordance with the dot clock signal DCLK so as to output the first correction data Dh 1 in-phase with the image data Db.
[0106] Next, the operation of the second correction unit Uh 2 will be explained. FIG. 5 is a timing chart showing the operation of the second correction unit Uh 2 . When the second subtracter circuit 51 is fed with the image data Da, it subtracts the reference data Dref from the image data Da (current), thereby generating the second difference data Dy. By way of example, in the time period Tx indicated in the figure, the second difference data Dy becomes data “D 2 ,n−Dref”.
[0107] As shown in FIG. 14, the equivalent capacitances constituted by the parasitic capacitances of the data lines 114 a - 114 f and the capacitances of the pixel capacitors are capacitively coupled. Therefore, when a voltage which is applied to any of the equivalent capacitances changes, the error voltage Ve 2 corresponding to the magnitude of the change is induced in the counter electrode, and the whole pertinent block is affected. Since the whole block is affected by the voltage change of a certain one of the data lines 114 a - 114 f , the second averaging circuit 52 is used in order to reflect this change in the video signals in advance.
[0108] In a similar manner to that of the first averaging circuit 42 averaging the first difference data Dx, the second averaging circuit 52 averages the second difference data Dy every block, thereby generating the second average data Dw 2 . When the second average data Dw 2 is fed to the coefficient circuit 53 , it is multiplied by the second coefficient K 2 . The resulting data, however, is out of phase with the image data Db, as illustrated in the figure. Therefore, the latch circuit 54 latches the output data of the coefficient circuit 53 in accordance with the dot clock signal DCLK so as to output the second correction data Dh 2 in-phase with the image data Db.
[0109] Further, the first and second correction data Dh 1 and Dh 2 are subtracted from the image data Db, whereby the corrected image data Dout is generated. The corrected image data Dout is converted into an analog signal through the D/A converter 301 , and the analog signal is fed to the phase expansion circuit 302 as the video signal VID.
[0110] Next, the operation in which the phase-expanded video signals VID 1 -VID 6 are generated on the basis of the video signal VID will be explained. FIG. 6 is a timing chart showing the operation of the phase expansion circuit 302 .
[0111] When the video signal VID is fed to the phase expansion circuit 302 , the sample-and-hold circuits SHa 1 -SHa 6 extend the time axis of the video signal VID by a factor of six and divide the extended video signal into six channels in synchronization with the corresponding sample-and-hold pulses SP 1 -SP 6 , thereby generating the respective signals vid 1 -vid 6 shown in the figure. Further, the sample-and-hold circuits SHa 1 -SHa 6 sample-and-hold the signals vid 1 -vid 6 in synchronization with the sample-and-hold pulse SS, thereby generating the video signals VID 1 -VID 6 , respectively.
[0112] Here, the operation in which the ghost is cancelled will be concretely explained. FIG. 7 is a timing chart of the phase-expanded video signals VID 1 -VID 6 in the case of phase-expanding the video signal VID by feeding the image data Da to the D/A converter 301 without employing the deghosting circuit 304 , and the corrected image data Dout generated by employing the deghosting circuit 304 . In FIG. 7, in order to facilitate understanding, data values are expressed in terms of the levels of the analog signals, and delay times due to the phase expansion are ignored. In this example, it is assumed that the same display as in FIG. 13A is presented and that the initial voltage Vs is the gray level Vc.
[0113] As shown in FIG. 7, the image data Da takes the data value corresponding to the black level Vb for the time period t 0 -t 10 , and it takes the data value corresponding to the gray level Vc for the time period t 10 -t 18 . Therefore, the phase-expanded video signals VID 1 -VID 4 shift from the level Vb to the level Vc at the time t 12 at which the selection time period of the block B 4 changes over to that of the block B 5 . On the other hand, the phase-expanded video signals VID 5 and VID 6 shift from the level Vb to the level Vc at the time t 6 at which the selection time period of the block B 3 changes over to that of the block B 4 .
[0114] A voltage Vcom 1 which is induced in the counter electrode due to the first factor appears in accordance with the change of each of the phase-expanded video signals VID 1 -VID 6 . Accordingly, the waveform of the induced voltage Vcom 1 becomes a differential waveform at the time t 6 and the time t 12 , as shown in the figure.
[0115] Besides, a voltage Vcom 2 which is induced in the counter electrode due to the second factor appears in accordance with the change of each of the phase-expanded video signals VID 1 -VID 6 . Accordingly, the waveform of the induced voltage Vcom 2 becomes a differential waveform at the time t 6 and the time t 12 , as shown in the figure. The polarity of the induced voltage Vcom 2 , however, becomes opposite to that of the induced voltage Vcom 1 .
[0116] A voltage Vcom which is actually induced in the counter electrode is given by the total of the induced voltages Vcom 1 and Vcom 2 , and the value of the voltage Vcom at the time at which the selection time period of each block ends becomes the error voltage Ve. Accordingly, the absolute value of the error voltage Ve of the block B 4 becomes 4β(Vb−Vc)−2α(Vb−Vc), while the absolute value of the error voltage Ve of the block B 5 becomes 4α(Vb−Vc).
[0117] In the deghosting circuit 304 according to this embodiment, as explained before, the first correction data Dh 1 based on the first factor is generated by the first correction unit Uh 1 , while the second correction data Dh 2 based on the second factor is generated by the second correction unit Uh 2 . The first and second correction data Dh 1 and Dh 2 correspond to the error voltages Ve 1 and Ve 2 , respectively.
[0118] Here, letting signs Vea, Veb, and Vec denote the differences between the counter electrode voltage Vcom and its center voltage at the times t 6 , t 12 , and t 18 , the corrected image data Dout obtained by the deghosting circuit 304 becomes as shown in FIG. 7. Also in this case, a voltage is induced in the counter electrode in accordance with the change of each of the phase-expanded video signals VID 1 -VID 6 or the proportion of the black level in a certain block. Since, however, the corrected image data Dout has been corrected in consideration of the differences Vea, Veb, and Vec shown in FIG. 7, the induced voltage of the counter electrode can be cancelled. Accordingly, even in the case where the black level changes to a gray level within a block, it is permitted to cancel the block ghosting which appears in the pertinent block and in the following block, and to strongly enhance the quality of the displayed image.
[0119] Next, modifications to the foregoing embodiments will be described.
[0120] In the foregoing embodiment, the D/A converter 301 is interposed between the deghosting circuit 304 and the phase expansion circuit 302 . It is to be understood, however, that it is possible to construct either of the phase expansion circuit 302 and the amplifier/inverter circuit 303 out of a digital circuit, and to dispose the D/A converter 301 on the output side of the digital circuit without departing from the spirit and scope of the present invention.
[0121] In the foregoing embodiment, the phase expansion circuit 302 includes the first sample-and-hold unit USa and the second sample-and-hold unit USb shown in FIG. 3, and the signals vid 1 -vid 6 are phased by the second sample-and-hold unit USb. It is also to be understood, however, that it is possible to omit the second sample-and-hold unit USb. In this case, the signals vid 1 -vid 6 whose phases shift every dot clock cycle may be outputted as the phase-expanded video signals VID 1 -VID 6 .
[0122] Next, examples in which the liquid-crystal display devices explained in the foregoing embodiments are applied to electronic equipment will be described.
[0123] A projector which employs the liquid-crystal display device as a light valve will be explained first. FIG. 8 is a plan view showing an example construction of the projector. As shown in the figure, a lamp unit 1102 including a white light source, such as halogen lamp, is disposed inside the projector 1100 . Projection light emerging from the lamp unit 1102 is separated into three primary colors R, G and B by four mirrors 1106 and two dichroic mirrors 1108 which are arranged in a light guide 1104 . The lights of the three primary colors enter liquid-crystal panels 1110 R, 1110 B and 1110 G which act as light valves for the respective primary colors.
[0124] Each of the liquid-crystal panels 1110 R, 1110 B and 1110 G has the same construction as that of the foregoing liquid-crystal display panel 100 , and these liquid-crystal panels are respectively driven by primary color signals R, B and G which are supplied by video signal processing circuits (not shown). Further, the light modulated by these liquid-crystal panels enters a dichroic prism 1112 in three directions. In the dichroic prism 1112 , the light of the colors R and B is refracted at 90 degrees, whereas the light of the color G is transmitted straight through. The images of the respective colors are accordingly combined, with the result that a color image is projected on a screen or the like through a projection lens 1114 .
[0125] Incidentally, the light corresponding to the respective primary colors R, G and B enters the liquid-crystal panels 1110 R, 1110 B and 1110 G owing to the dichroic mirrors 1108 , so that color filters need not be disposed on the counter substrates.
[0126] As explained before, the deghosting circuit 304 or 305 is included in an image processing circuit 300 of the liquid-crystal display device. It is therefore possible to cancel the first or second ghost component and to strongly enhance the quality of the displayed image.
[0127] Next, an example in which the liquid-crystal display device is applied to a portable computer will be explained. FIG. 9 is a front view showing the construction of the computer. Referring to the figure, the computer 1200 is constructed of a body 1204 including a keyboard 1202 , and a liquid-crystal display 1206 including a liquid-crystal panel 1005 . The liquid-crystal display 1206 is constructed by attaching a back light onto the rear surface of the liquid-crystal panel 100 described above.
[0128] Further, an example in which the liquid-crystal display device is applied to a mobile telephone will be explained. FIG. 10 is a perspective view showing the construction of the mobile telephone. Referring to the figure, the mobile telephone 1300 includes a reflection-type liquid-crystal panel 1005 together with a plurality of operating buttons 1302 . The reflection-type liquid-crystal panel 1005 is furnished with a front light on its front surface, as required.
[0129] Apart from the electronic equipment described with reference to FIGS. 8 - 10 , the present invention can also be used in a liquid-crystal television set, a viewfinder-type or monitor direct-view-type video tape recorder, car navigation equipment, a pager, an electronic notebook, a pocket or desk calculator, a word processor, a workstation, a video telephone, a POS terminal, equipment including a touch panel, and the like.
[0130] As thus far described, according to the present invention, in a case where video signals generated by dividing an input video signal into a plurality of channels and extending the time axis thereof, so as to maintain a predetermined signal level every unit time, are fed to corresponding data lines at a predetermined timing, ghosting which appears in a display image is predicted even when a luminance level changes midway in a block, and image data is corrected so as to cancel the ghosting, so that the quality of the display image can be strongly enhanced.
[0131] 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, 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.
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The present invention provides an image processing circuit for use in an electrooptic device having a plurality of scanning lines, a plurality of data lines, switching elements which are respectively disposed in correspondence with intersections between the scanning lines and the data lines, and pixel electrodes which are electrically coupled to the corresponding switching elements. The image processing circuit includes a delay circuit that delays externally supplied image data by a unit time so as to output delayed image data, first correction-data generation circuit that generates correction data on the basis of data which has been obtained by averaging a difference between the image data and the delayed image data every unit time, second correction-data generation circuit that generates second correction data on the basis of data which has been obtained by averaging a difference between the image data and predetermined reference data every unit time, correction circuit that generates corrected image data by correcting the delayed image data on the basis of the first correction data and the second correction data, and a phase expansion circuit which divides the corrected image data into a plurality of phase-expanded video signals and which feeds the phase-expanded video signals to the plurality of data lines. Thus, block ghosting can be cancelled in a case where an image is displayed by successively selecting blocks in each of which a plurality of data lines are collected.
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BACKGROUND OF THE INVENTION
The present invention relates to electric motors, and more particularly to electric motors controllable to operate at a number of distinct output speeds.
Various electric motor controls have been used to control various electric motors to operate at multiple output speeds. Nevertheless, it would be desirable to have a new electric motor that is controllable by a less expensive controller to provide efficient operation at a number of distinct speeds.
SUMMARY OF THE INVENTION
Accordingly, the invention provides an electric motor that is controllable by an inexpensive controller to independently provide efficient operation at a number of distinct output speeds. The electric motor includes a single set of mechanical parts (e.g., housing, shaft, bearings, etc.) in combination with multiple sets of electromagnetic parts (e.g., first and second stators adapted to independently receive power from the controller and thereby produce first and second magnetic fields, respectively, and first and second rotating members connected to the shaft for rotation therewith and adapted to interact with the first and second magnetic fields), where the number of electromagnetic parts corresponds to the number of distinct output speeds of the electric motor. In some embodiments, each set of electromagnetic parts has a different configuration (e.g., a low speed set, a high speed set, etc.).
In one embodiment, the electric motor independently provides either a first or a second output speed. The motor includes two sets of electromagnetic parts (i.e., a first stator and a first rotating member, and a second stator and a second rotating member). The controller independently provides the electric motor either a first or a second power, where the first power corresponds to the first speed and the second power corresponds to the second speed. When the first power is provided, the first stator receives the first power and produces a first magnetic field. The first rotating member interacts with the first magnetic field and, as a result of the interaction, the rotor rotates at the first output speed. Similarly, when the second power is provided, the second stator receives the second power and produces a second magnetic field. The second rotating member interacts with the second magnetic field and, as a result of the interaction, the rotor rotates at the second output speed.
The electric motor of the invention can be used in many different environments requiring low numbers (e.g., 2, 3) of distinct output speeds. For example, the electric motor can be incorporated in a heating, ventilation, and air conditioning (HVAC) system to drive a blower assembly at either the first speed or the second speed. The first and second speeds provide a first or a second volume of air, respectively, to the environment the HVAC system is conditioning.
In other embodiment, the electric motor provides a different number of output speeds and/or is incorporated in other systems.
Other features of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a HVAC system incorporating an electric motor of the present invention.
FIG. 2 is a sectional view of the electric motor shown in FIG. 1 .
FIG. 3 is a schematic diagram of the electric motor shown in FIG. 1 and a controller connected to the motor.
DETAILED DESCRIPTION
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” and “coupled” are used broadly and encompass both direct and indirect mountings, connections, and. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
FIG. 1 schematically illustrates an HVAC system 5 having an electric motor 10 of the invention. The electric motor 10 is electrically coupled to a controller 15 and drivingly coupled to a driven unit 20 . As described herein, the HVAC system 5 is a dual capacity heating and cooling system, the functionality of the controller 10 is incorporated in the controls of the HVAC system 5 , and the driven unit 20 is a blower assembly which delivers either a first or a second volume of air to the environment conditioned by the HVAC system 5 . The controller 15 independently provides either a first power V 1 (e.g., an alternating current (AC) power, a direct current (DC) power, etc.) or a second power V 2 (e.g., an AC power, a DC power, etc.) to the motor 10 based on a user input (e.g., an adjustment of a thermostat associated with the HVAC system 5 ) and/or a feedback (e.g., a trigger resulting from a failure to reach a commanded temperature in the environment conditioned by the HVAC system in a set amount of time). As described further below, supplying the first power V 1 to the motor 10 results in a first output motor speed S 1 , and supplying the second power V 2 to the motor 10 results in a second output motor speed S 2 . When the blower assembly 20 is driven at the first output speed S 1 , the first volume of air is provided to the environment, and when the blower assembly 20 is driven at the second output speed S 2 , the second volume of air is provided to the environment. The motor 10 is capable of use in other systems and the HVAC system 5 is shown and described as an example of one such system.
As used herein, the first and second output speeds S 1 and S 2 , respectively, may include a range of output speeds. Description of the output speeds S 1 and S 2 as distinct output speeds refers to the generally unvaried supply of the first and second powers V 1 and V 2 which are utilized to generate the first and second output speeds S 1 and S 2 . Although the output speeds S 1 and S 2 may vary based on characteristics of the motor 10 and/or loads applied to the motor 10 , the speeds S 1 and S 2 generally will not vary based on the control provided by the controller 15 . In one embodiment, the first output speed S 1 is a low speed (e.g., 550 revolutions per minute (RPM)) and the second output speed S 2 is a high speed (e.g., 1075 RPM).
As shown in FIG. 2, the motor 10 includes a housing 25 , a first stator 30 fixed relative to the housing 25 , a second stator 35 fixed relative to the housing 25 , and a rotor 40 . The rotor 40 includes a shaft 45 rotatable relative to the housing 25 about an axis 50 , a first rotating member 55 connected to the shaft 40 for rotation therewith relative to the first stator 30 , and a second rotating member 60 connected to the shaft 45 for rotation therewith relative to the second stator 35 .
The first and second stators 30 and 35 , respectively, are independently electrically coupled to the controller 15 to receive power. In one embodiment, as shown in FIG. 3, the first stator 30 receives the first power V 1 and the second stator 35 receives the second power V 2 . When the first stator 30 receives the first power V 1 , the first stator 30 produces a first magnetic field, and when the second stator 35 receives the second power V 2 , the second stator 35 produces a second magnetic field. The first rotating member 55 interacts with the first magnetic field to produce a first torque in the rotor 40 causing the rotor 40 to rotate at the first output speed S 1 . The second rotating member 60 interacts with the second magnetic field to produce a second torque in the rotor 40 causing the rotor 40 to rotate at the second output speed S 2 .
As shown in FIG. 3, in one embodiment, the motor 10 includes a permanent split capacitor induction motor. Each stator 30 and 35 includes a main winding W 1 and a starting or an auxiliary winding W 2 . Each auxiliary winding W 2 is connected in series with a capacitor C for startup and normal operation of the motor 10 . The first and second rotating members 55 and 60 , respectively, include a laminated core, conductor bars running parallel to the axis 50 , and conducting rings located on the longitudinal ends of each rotating member 55 and 60 and electrically coupled to the conductor bars.
As the first power V 1 (e.g., a first AC power) is passed through the windings W 1 and W 2 of the first stator 30 , a moving magnetic field (i.e., the first magnetic field) is formed near the energized stator 30 . The moving magnetic field induces a current in the first rotating member 55 , thereby forming a magnetic field near the first rotating member 55 . Interaction between the field of the first stator 30 and the field of the first rotating member 55 produces a torque on the rotor 40 which causes the rotor 40 to rotate at the first output speed S 1 . Similarly, supply of the second power V 2 to the windings W 1 and W 2 of the second stator 35 results in the rotor 40 rotating at the second output speed S 2 . In one specific embodiment, the first and second powers V 1 and V 2 , respectively, are electrically the same.
In other embodiments, the motor 10 includes other types of motors (e.g., AC motors, DC motors, brush motors, brushless motors, etc.) and other types of induction motors (e.g., split-phase, capacitor start/induction run, capacitor start/capacitor run, shaded-pole, etc.).
In the illustrated embodiment, the first and second stators 30 and 35 , respectively, each include a standard speed connection HIGH and two alternative speed connections MED and LOW. In other embodiments, the first and second stators 30 and 35 may each independently include different numbers of alternate speed connections (e.g., the first stator 30 includes a standard speed connection and no alternate speed connections, and the second stator 35 includes a standard speed connection and three alternate speed connections). Alternative speed connections are commonly known as taps. The alternative speed connections allow the individual installing the HVAC system 5 to adjust the first and second speeds S 1 and S 2 to fit the particular installation. Variation in equipment and ductwork design changes the first and second volumes of air needed to optimally condition the environment of the HVAC system. Utilization of the alternative speed connections provides flexibility in the installation process. In other embodiments, the first and second stators 30 and 35 may include multiple sets of main windings W 1 and/or auxiliary windings W 2 for adjusting the output speeds S 1 and S 2 .
In the illustrated embodiment, the first stator 30 includes ten poles and the second stator 35 includes six poles. In other embodiments, the stator configurations can vary. Further, the first stator 30 and the first rotating member 55 form a low speed, high efficiency set of electromagnetic parts and the second stator 35 and the second rotating member 60 form a high speed, high efficiency set of electromagnetic parts. Utilization of such sets allows for efficient operation at each of the distinct output speeds.
In one embodiment, the controller 15 is implemented using a programmable device (e.g., a microprocessor, a microcontroller, a digital signal processor (DSP), etc.) that utilizes software stored in a memory and a discrete power component (e.g., a switch such as a relay, etc.). In other embodiments, the controller 15 may be implemented using other combinations of software and hardware or using solely software or hardware.
Based on a user input and/or a feedback, the controller 15 provides either the first power V 1 or the second power V 2 to the motor 10 . In one embodiment, the first and second powers V 1 and V 2 are both 115 volt/60 Hz power. In other embodiments, the first and second powers V 1 and V 2 include other powers (e.g., 230 volts/60 Hz AC power, etc.).
Various features of the invention are set forth in the following claims.
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An electric motor controllable to operate at a number of distinct output speeds. The electric motor includes a single set of mechanical parts in combination with a multiple sets of electromagnetic parts having different configurations, where the number of electromagnetic parts corresponds to the number of distinct output speeds of the electric motor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus and method for quickly and completely automatically producing a compressed, rolled package of resilient foam material. The invention utilizes a unique wrapper sheet delivery system whereby adhesive is applied to one surface of the wrapper sheet. The foam product and the wrapper sheet are then compressed and rolled. The wrapper sheet adheres to the circumference of the foamed material package, and to itself, to maintain the package in a tightly rolled and compressed state.
2. Description of the Prior Art
U.S. Pat. No. 3,927,504 discloses a method and apparatus of making a compressed, rolled package of resilient compressible foamed sheet material wherein a cylindrical roller engages and compresses an edge of the foamed sheet material causing the foam material behind the roller to curl up and fold over upon itself. Directly behind the cylindrical roller is a carrier which continues the pressurized engagement with the rolling foamed material and continues the rolling of the package until it is formed into a compressed rolled package. This patent further discloses the wrapping of the compressed rolled foam material with a plastic wrapping sheet to maintain the package in a compressed rolled state.
The apparatus of this patent utilizes a stationary table 10 upon which a foam sheet (S) and a wrapping sheet (W) are manually placed and arranged for subsequent rolling and wrapping. The rolling and wrapping operation is accomplished by advancing carrier 20, having cylindrical roll 35 at its leading edge, over the foam sheet and wrapper sheet respectively. The typical operation of this apparatus is to have a workman place and position the foam sheet and the wrapper sheet on the table and then to activate the moving carrier (20) to perform the rolling and wrapping operation.
U.S. Pat. No. 3,710,536 discloses a method and apparatus for automatically compressing and banding a stack of compressible articles. A stack of articles is fed along a path and a pair of banding or wrapping sheets are brought into engagement with the stack. The stack is compressed between oppositely directed forces and the ends of the wrapping sheets are overlapped and joined to form an endless band around the articles. When the compressive forces are relieved, the articles are held in a compressed and stacked state by the wrapping sheets. The individual wrapping sheets are severed from long supply webs, separated into sections by score lines, perforations or other types of pre-weakened areas, prior to being joined into an endless band around the compressed stack.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to provide a method and apparatus for completely automatically packaging a rolled and compressed foam piece with a flexible sheet material.
It is a further important object of the present invention to utilize a long length of flexible wrapping sheet material, in the form of a roll of flexible sheet material, divided into a plurality of sections separated by pre-weakened areas along its length.
It is a still further important object of the present invention to provide a method and apparatus for automatically feeding such a flexible sheet material, in the form of a rolled length which is divided into a plurality of sections separated by pre-weakened areas, and automatically separating and feeding individual wrapper sections from the length of flexible sheet material for wrapping a rolled and compressed foam piece.
These and other objects are met by a method and apparatus for packaging a rolled and compressed foam piece with a flexible sheet material wherein the flexible sheet material is fed to an upstream set of clutch-brake nip rolls and engaging the clutch-brake nip rolls to feed the flexible sheet material to a downstream set of drive nip rolls. The flexible sheet material is guided during its travel between the two set of nip rolls. After the drive nip rolls have engaged the leading edge of the flexible sheet material, the brake in the clutch-brake nip rolls engages which exerts a drag on the advancing sheet material. This drag creates a tension on the flexible sheet material which is sufficient to tear it along a pre-weakened area. As soon as a pre-weakened area advances to a position between the two sets of nip rolls, the sheet material tears at the pre-weakened area and a separated single wrapper section is advanced by the drive nip rolls apart from the remainder of the flexible sheet material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of an apparatus comprising one specific embodiment of the present invention.
FIG. 2 is a side elevation, partly in section, of a set of nip rolls according to the present invention.
FIG. 3 is a side elevation of a rolled and compressed foam piece just prior to completion of the rolling operation.
Although specific forms of apparatus embodying the invention have been selected for illustration in the drawings, and although specific terminology will be resorted to in describing those forms in the specification which follows, their use is not intended to define or to limit the scope of the invention, which is defined in the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 the packaging apparatus is designated as 10. Furthermore, with respect to the packaging apparatus 10 and/or any individual part thereof, the side or end closest to the convolutor shall be designated upstream, and the side or end closest to the rolling device shall be designated downstream.
In the method and apparatus illustrated in the figures, the foam piece is a convoluted foam pad 18 which is manufactured in a well-known manner by feeding a sheet of foam material into a convoluter (not shown in the figures). In the convoluter, the foam sheet material is cut into two convoluted foam pads 18 which are then fed to conveyor belts which move the pads downstream to the rolling and packaging apparatus 10. Thus, as one convoluted foam pad 18 exits from the convoluter it is fed, convoluted side up, onto endless belt 12 of conveyor 11 which is driven in a known manner by drive roller 13. Upon reaching the end of conveyor 11, the foam pad 18 is deposited on, and slides down, metal ramp 14 onto conveyor 15 comprised of an endless belt 16 driven by drive roller 17.
At the same time that convoluted foam pad 18 is being conveyed along conveyors 11, 15 and ramp 14, the wrapper feed device 19 is activated to advance a plastic wrapper section 42 into adhesive contact with the flat or non-convoluted side of the foam pad 18. Preferably, the plastic wrapping material is in the form of a continuous roll 30 of perforated plastic sheet material. The plastic sheet 31 is divided into individual wrapper sections by perforations running across the width of the plastic sheet 31. A preferable plastic sheet material is polyethylene or polyurethane.
Thus, in a known manner, the plastic sheet 31 is unwound from roll 30 and runs over idler roller 32 to the wrapper feed device 19. Wrapper feed device 19 comprises two sets of nip rolls; an upstream set of clutch-brake nip rolls 33a, b and a downstream set of drive nip rolls 34a, b. Both sets of nip rolls 33 and 34 are preferably composed of neoprene rubber of 35 dural hardness. In typical packaging operations the nip rolls 33, 34 will have a diameter of approximately 4 inches and a length of approximately 4 feet.
Referring now to FIG. 2 of the drawings, the set of clutch-brake nip rolls 33 is illustrated from a side view, shown partly in section. Although the set of clutch-brake nip rolls 33 was chosen for further illustration in FIG. 2, the set of drive nip rolls 34 has the same shape and configuration so that many of the features of clutch-brake nip rolls 33 shown in FIG. 2 are also present in the drive nip rolls 34. As can be seen, nip roll 33a has a plurality of grooves 50a in its surface. Grooves 50a run completely around the circumference of the roll 33a. Likewise, roll 33b has a plurality of grooves 50b in its outer surface. The depth of the grooves 50a and 50b is typically 0.25 inches. The width of the grooves 50a and 50b is typically 0.125 inches. Successive grooves are spaced approximately 1.5 inches apart along the length of each roll 33a, b. As can be seen in FIG. 2, the number, position and spacing of the grooves 50a exactly corresponds with the number, position and spacing of the grooves 50b so that the grooves 50a and 50b are exactly adjacent one another at the nip point of the clutch-brake rolls 33a, b.
Positioned within the grooves 50a are a plurality of guide wires 35a, one guide wire 35a positioned in each groove 50a. Likewise, a plurality of guide wires 35b are each positioned in grooves 50b. As can be seen in FIG. 1, the guide wires 35a and 35b provide a path for the advancing plastic sheet 31 between the two sets of nip rolls 33, 34. The guide wires are supported at their ends by attachment to supports 36, 37, 38 and 39 in a known manner.
Attached to the downstream side of support 39 are a plurality of adhesive sprayers 41 positioned to spray adhesive on the wrapper sections 42.
In the operation of the wrapper feed device 19, the plastic sheet 31 is unrolled from roll 30 over idler roller 32 to the set of clutch-brake nip rolls 33a, b. At this point, the clutch-brake nip rolls 33a, b engage to feed the plastic sheet 31 toward the downstream set of drive nip rolls 34a, b. During the advance of the sheet 31 between the two sets of nip rolls 33, 34, the plastic sheet 31 is guided between the two sets of guide wires 35a, b. When the forward edge of the plastic sheet 31 reaches the nip between the drive nip rolls 34a, b the clutch of the clutch-brake rolls disengages and the downstream edge of sheet 31 is taken up by the drive nip rolls 34a, b. After the clutch of the clutch-brake rolls 33a, b disengages, the brake on the clutch-brake rolls 33a, b engages thereby exerting a drag on the advancing sheet material 31. The tension exerted on the sheet material 31 by the drive nip rolls 34a, b and the braked clutch-brake rolls 33a, b is sufficient to tear the plastic sheet material 31 across the perforations but is insufficient to tear the plastic sheet material in any other areas. Thus, as soon as a line of perforations advances to a point between the two sets of nip rolls 33, 34, the sheet material 31 will tear along the perforations and a single wrapper section 42 will be advanced by the drive nip rolls 34a, b. As the single section 42 advances beyond nip rolls 34a, b, it is sprayed with adhesive by the adhesive sprayer 41 while supported by support 40. Thus the single wrapper section 42, having one side thereof sprayed with adhesive, is deposited on the endless belt 16 of conveyor 15.
The advance of the single wrapper section 42 is timed such that the trailing portion of convoluted foam pad 18 is dropped off of ramp 14 onto the leading portion of the individual wrapper section 42. Since the entire surface of the wrapper sheet 42 is coated with adhesive, the area of overlap between the convoluted foam pad 18 and the single wrapper section 42 provides adhesive contact between the convoluted foam pad 18 and the single wrapper section 42 which are then conveyed by endless belt 16 to rolling device 25.
Referring to both FIGS. 1 and 3, rolling device 25 comprises a stationary inclined plate 21 having a roughened surface 26 on its lower side. At the upstream edge of inclined plate 21 is positioned an air delivery tube 22 having a plurality of jets spaced along the length of the tube 22. The purpose of the air jets is to ensure that the plastic wrapper sheet 42 lies flat on the endless belt 16. Sometimes, during operation of the machine, the force of the spray from the adhesive sprayers will cause the trailing edges of the individual wrapper sections 42 to fold over. Thus, the air jets spaced along the upstream edge of plate 21 assures that the upstream portion of section 42 lies flat on endless belt 16.
Immediately below endless belt 16 in the region of inclined plate 21 is a support table 20. Support table 20 is provided to prevent deflection of endless belt 16 during the compression rolling of convoluted foam pad 18, which will be described in more detail hereinafter.
The height between the upstream edge of incline plate 21 and the endless belt 16 is adjusted for the particular size convoluted pad 18 being rolled and in any event is somewhat less than the height of the convoluted pad 18. Thus, as the downstream edge of convoluted pad 18 encounters the upstream edge of the incline plate 21, the pad 18 is forced to curl up and roll over on itself in a known manner as shown in U.S. Pat. No. 3,927,504 which is incorporated herein by reference. Furthermore, the angle of inclination of plate 21 is adjusted so that the pad 18 is continuously rolled under a substantially uniform compression into a tightly rolled and compressed package as is clearly shown in FIG. 3.
It will be appreciated that the incline plate 21 may be constructed of wood or any other desirable material. However, it is preferable to provide it with a roughened surface 26 in order to prevent any sliding movement of the foam pad 18 or of the wrapper sheet 42 during the rolling operation. As is clearly shown in FIG. 3, the wrapper sheet 42 having one face thereof completely covered with adhesive, is in contact with, and adheres to, the foam pad 18 along its entire circumference and prevents any loss of compression in the compressed foam roll after the compressed and rolled package has been freed from between the incline plate 21 and the endless belt 16 for further handling.
A typical further handling step is to heat seal the open ends of the wrapper sheet 42 with a hot wire sealing device (not shown).
It will be appreciated that many other modifications may be made without departing from the scope of this invention. For example, certain parts may be used independently of others, parts may be reversed, and equivalent elements may be substituted for those selected for illustration in the drawings, all without departing from the spirit and scope of the invention as defined in the appended claims.
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Apparatus and method are provided for producing a compressed, rolled package of resilient foam material, wrapped with a flexible sheet material which is divided into a plurality of sections separated by pre-weakened areas along its length. The flexible sheet material is advanced by an upstream set of clutch-brake nip rolls and a downstream set of drive nip rolls. The two sets of nip rolls are operated in such a manner as to separate a single wrapping sheet from the length of flexible sheet material and to advance the single sheet into contact with the foam piece for feeding to a rolling and compressing packaging apparatus.
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FIELD OF THE INVENTION
This invention involves poultry chillers for reducing the temperature of whole birds after the birds have been eviscerated on a poultry processing line.
BACKGROUND OF THE INVENTION
It is desirable to reduce the temperature of chickens and other type poultry after the birds have been processed, are defeathered, eviscerated and are otherwise oven-ready and before the birds are packaged for delivery to the retail customer. A conventional poultry chiller is the “auger type” chiller which includes a trough-shaped half-round tank filled with ice water in which the auger provides positive movement of the birds through the tank. The cooling effect for the water and the birds was originally provided by crushed ice added to the water. The later designs include a counter-flow recirculation of the chilled water through the tank, with the water being chilled by a refrigerated heat exchanger instead of using ice. The water is introduced at one end of the tank and flows progressively to the other end, where it is recirculated. In the meantime, the birds are continually delivered to the tank and moved under the influence of the auger in the counter-flow direction, and are lifted from the delivery end of the tank for further processing. A prior art poultry chiller of this general type is disclosed in U.S. Pat. No. 5,868,000, and a heat exchanger for the water refrigeration system suitable for this purpose is shown in U.S. Pat. No. 5,509,470.
The trough-shaped tanks of the chillers can be five to ten feet in diameter. The United States Department of Agriculture rules require one-half gallon of fresh makeup water to be added to the chiller for each bird that is processed through the chiller, which is 70 gallons per minute for a processing line that moves 140 birds per minute. The fresh makeup water is added to the tank at the delivery end of the tank, where the birds have been chilled and are being lifted out of the tank. The water flows against the birds in the opposite direction of movement of the birds and the auger of the tank, and the water overflows at the bird inlet end of the tank, assuring that the birds are always flowing into the cleanest water and that there is always a temperature drop between the temperature of each bird and the temperature of the water about each bird.
One of the problems of counter-flowing the refrigerated water through the tank is that the auger, by its rotation as it moves the birds forward, also pushes approximately the same volume of water toward the bird outlet end, along with the birds. The water must find its way back in counter-flow direction with respect to the birds and to the moving surfaces of the auger.
It is desirable that the augers of the chillers utilize solid auger flights so as to prevent the birds becoming trapped or hanging against the auger and not moving properly through the tank, and to avoid damaging the birds. Because of the desirability to employ augers with solid flights, the accepted way to move the water through the tank in a counter-flow direction with respect to both the auger and the birds is to flow the water around the outside perimeter of the auger flights, between the auger and the facing surface of the tank, which is normally limited to a small dimension, such as between 1 inch and 1½ inches clearance space. This small space at the perimeter of the auger avoids having the smaller birds becoming caught or trapped between the auger and the tank, and avoids damage to the birds.
Usually, the auger of the chiller has a 360° flight every 4 linear feet of the auger. Therefore, the water is required to flow about the peripheries of several auger flights when moving along the tank.
In addition to the critical restriction of water flow through this narrow restriction between the perimeter of the auger flights and the facing surface of the tank there is an additional restriction at the perimeter of the auger blades by the birds which tend to follow the path of the water about the blade and partially block the perimeter opening about the auger blades. This significantly limits the amount of water that can be circulated through the birds at this position in the tank, thereby resulting in inadequate cooling of the birds.
Also, since the counter-flow water movement that occurs in this arrangement flows only around the edges of the flights of the auger, and not uniformly through the mass of birds at the centerline of the tank, there is a lack of uniformity and effectiveness in chilling the birds that are at the centerline of the tank or which are “clumped” or clustered together in the tank. Typically, most of the birds will migrate toward one sidewall of the tank because of frictional contact with the rotating auger, leaving the opposite side of the tank with fewer birds, and the major circulation of water is about the edges of the auger flight that is free of birds and therefore open for water movement.
Another problem with the typical prior art auger driven poultry chiller is that when the operation of the processing line which delivers birds to the chiller is being progressively terminated between shifts of the workers in the plant, by terminating the introduction of birds to the processing line and allowing the birds already on the line to move through the line, the absence of delivery of birds to the chiller tank in combination with the removal of birds from the delivery end of the tank results in less volume of birds and water in the tank, causing a reduction in the water level of the tank. This means that the water has even less space to pass around the perimeter of the auger blade to the next segment of the tank, resulting in starving the downstream segments of the tank of water. The reduction of supply of water in the last segment of the tank may result in starving the circulating pump of water.
It is to the above noted problems of the prior art that this invention is directed.
SUMMARY OF THE INVENTION
Briefly described, the present invention comprises a chiller for previously eviscerated oven-ready whole poultry birds which utilizes a trough-shaped open top, half-round tank and a rotary auger that is partially submerged in the tank. Chilled water is delivered to the first end of the tank and moves in a counter-flow relationship with respect to the auger and birds that are moving in the tank.
The auger includes an auger shaft that extends along the length of the tank at the anticipated level of the water in the tank with a helical blade structure formed about the shaft so that approximately one-half the helical blade structure will be submerged in the water while the other half protrudes upwardly out of the water. This separates the tank into segments that confine the birds in separate groups moving along the tank, so that all of the birds are retained in the tank for an equal time. The helical blade structure includes helical segments, with the segments being offset axially of the auger shaft, so that the segments overlap one another longitudinally. This longitudinal offset of the helical segments with each other forms water passages through the helical blade structure at intervals along the auger. In the embodiment disclosed herein, these water passages extend axially along the auger shaft and face approximately tangentially of the auger shaft and intersect the perimeter of the auger segments. Typically, the water passages formed by the adjacent overlapping auger segments are formed at each 180° interval about the auger. The placement of water passages at intervals of 180° about the auger assures that at least one water passage for each 360° turn of the helical auger blade structure is submerged in the chilled water so as to continuously provide passage for the water through all segments of the tank. In some instances, it may be desirable to have more water passages per 360° turn of the helical blade structure of the auger. This is particularly so when the width of the chiller tank and the diameter of the auger are increased.
The water passages are arranged so that they tend to move with the auger away from the birds as the auger rotates, so that the birds naturally tend to avoid moving through the water passages during the operation of the chiller. Also, grills extend over the water passages so as to avoid any inadvertent movement of birds through the water passages. In a preferred embodiment, the grills at the water passages are formed of parallel, spaced bars that extend radially from the auger shaft out to the perimeter of the helical blade structure. This radial arrangement of the grill bars assures that the birds that might come in contact with a grill will always be able to fall from the grill as the grill is lifted above the level of the water, so that as the bars of the grill become vertically oriented there is no impediment to hold the birds on the grill.
In effect, the segmented helical blade structure amounts to cutting the blade flight at each half revolution of the auger blade, sliding the portion of the flight that is toward the bird-inlet end straight back on the shaft to provide the space that becomes the water passage. This causes the water passage to face circumferentially or tangentially of the auger shaft as opposed to axially of the auger. The water moving through the water passages tends to circulate in each segment of the tank between adjacent flights of the auger and thereby increases the tendency to move the birds in the body of water, to contact the warmer birds and to rapidly chill the birds.
This effective sliding of the cut flight backward on the auger shaft also assures that birds being pushed forward by the helical blade structure are momentarily relieved of contact with the auger blade and the pushing of the birds by the surfaces of the auger is intermittently terminated as each water passage moves past the birds. This tends to break up and reorient the birds from clumps or clusters of birds that may have formed in the water and it assures that the chilled water will have greater access to all surfaces of the birds for uniform chilling of the birds.
Since the water level in the tank normally can achieve a height of from level to the auger shaft to approximately 12 inches above the upper surface of the auger shaft, the helical blade structure having water passages at each 180° turn of the helical blade structure assures that one water passage and its grill on each flight is always fully submerged to allow the water full access to a complete water passage at all times.
Although the speed of operation of the auger is variable, the typical speed is one revolution per four minutes in a 10 foot diameter tank. The movement of the auger creates some tumbling action of the birds, particularly as the water passages with their stainless steel grills move through the bird mass. Also, since the water passages extend radially outward from the auger shaft as opposed to only at the perimeter of the auger, the force of the water is felt more uniformly through the center of the tank than only at the perimeter as was achieved by the prior art chillers. This tends to more uniformly and more rapidly cool the birds in the water. This is important since the birds must be chilled below the specified maximum temperature of 40° F. when leaving the chiller, because if the poultry inspector finds an occasional bird above the maximum leaving temperature, the inspector will stop the entire plant operation, including the eviscerating line, for a 15 minute interval to allow additional chilling time for the birds in the chiller, until the specified temperatures are achieved in every bird in the tank. Therefore, the uniform and more rapid chilling achieved by this invention in comparison to the prior art has the potential of reducing the length of the tank, of increasing the speed of rotation of the auger, or in either of the prior instances, of reducing the time of each bird in the chiller. This reduction in chilling time has an indirect benefit in that at the end of a shift in a poultry processing plant, there will be more time available to the workers to clean the chiller before the next work shift commences.
Therefore, it is an object of this invention to provide an improved chiller for poultry and other carcasses for more rapidly and more uniformly chilling the birds received from a processing line.
Another object of this invention is to provide a poultry chiller that has a short bird residence time in the chiller while still achieving the desired reduction in bird temperature.
Another object of this invention is to provide a poultry chiller which more thoroughly distributes the cold water through the tank and about the birds and which tends to reduce the tendency of the birds to become clustered together in masses of birds that would result in less effective chilling of the birds.
Another object of this invention is to provide an improved chiller that requires less floor space in a poultry processing plant.
Another object of this invention is to provide a poultry chiller which, by requiring a shorter residence time for the birds in the chiller, provides more cleanup time after the operation of the hiller has been terminated and before its operation is resumed.
Another object of this invention is to provide an improved poultry chiller that reduces the tendency of water starvation at the last segments of the chiller tank at shutdown of the operation of the tank.
Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the poultry chiller.
FIG. 2 is a partial plan view of a portion of the poultry chiller.
FIG. 3 is a side cross sectional view of a portion of the poultry chiller.
FIG. 4 is a perspective illustration of a water passage between adjacent helical segments of the auger blade structure, and a grill positioned in the water passage.
FIG. 5 is a schematic side elevational view of a portion of a chiller, showing the movement of the birds in a portion of the chiller.
FIG. 6 is an end view of the auger and tank, taken along lines 6 — 6 of FIG. 5 .
FIG. 7 is a perspective illustration of another embodiment of the invention, showing an alternate water passage structure.
DETAILED DESCRIPTION
Referring now in more detail to the drawings, in which like numerals indicate like parts throughout the several views, FIG. 1 illustrates the poultry chiller 10 that includes a trough-shaped water reservoir or tank 12 having a semi-cylindrical bottom wall 13 , end walls 14 and 16 , and a rim 18 formed at the upper edge of the bottom wall 12 . The tank forms a reservoir for chilled water.
An auger 20 is positioned in the tank 12 . Electric motor or other conventional power means 21 (FIG. 5) is arranged to rotate the auger. The auger includes an auger shaft 22 and a helical blade structure 23 formed around the shaft. The blade structure 23 is formed of a series of helical blade segments 24 A- 24 G (FIG. 1 ), each of which is mounted to the auger shaft 22 and rotates in unison with the auger shaft. Each blade segment 24 A- 24 G is offset axially with respect to the next adjacent blade segments along the length of the auger shaft 22 and the blade segments form gaps that function as water passages 26 for the passage of water along the tank.
As shown in FIGS. 2 and 3, the auger blade segments 24 A- 24 F are axially offset along the auger shaft 22 so that the gaps 26 extend axially of the auger shaft but face approximately tangentially or circumferentially with respect to the auger shaft. The gaps extend radially from the auger shaft entirely across the helical blade structure. The auger shaft 22 rotates in the direction indicated by arrow 28 , so that the faces 24 ′ (FIG. 3) of the helical blade segments 24 function as the bird engagement surfaces and the surfaces 24 ″ function as the opposed following surfaces. The water passages permit the movement of water 30 adjacent the bird engagement surfaces 24 ′ to a position adjacent the following surfaces 24 ″. This is illustrated by the arrows 32 in FIGS. 4, 5 and 6 .
In order to avoid having a bird 34 inadvertently move through a water passage 26 , a grill 36 is positioned in each water passage 26 . The grills 36 each include a plurality of elongated parallel bars 38 that extend radially from the auger shaft 22 to the perimeter 40 of the auger blade segments 24 . The gaps between the adjacent auger blade segments 24 are approximately 9 inches, and the length of the gap extending radially from the auger shaft 22 is 42 inches for an 8 foot diameter tank, with the auger shaft having a diameter of 12 inches. The bars that form the grill 26 are ⅝ inch diameter stainless steel rods placed on 3 inch centers. An additional bar 50 extends parallel to the auger shaft 22 and is mounted to the distal ends of the bars 48 , thereby bracing the bars as well as bracing the adjacent edges of the auger blade segments. If desired, additional brace bars 50 (not illustrated) can be placed at intervals along the length of the grill bars 48 for additional bracing of the bars 38 , as may be necessary. The grills function as deflector means which fend the birds away from the water passages.
The perimeter 40 of each auger blade segment 24 is a continuous spiral from one water passage to the next, while the portions of the auger blade segments located inwardly of the perimeter are folded for purposes of strength enhancement, as well as to provide a rectangular shape for the gaps that form the water passages 26 between adjacent ones of the auger blade segments.
While FIGS. 2-4 illustrate gaps that form water passages 26 at 180° intervals about the helical blade structure 23 , it will be noted from FIG. 6 that other structural arrangements can be provided by having the gaps formed at 120° intervals about the helical blade structure. This permits more passage of water along the tank through the helical blade structure of the auger, and is more desirable for the larger width chillers, such as the 12 foot wide chiller. Other intervals of water passages can be utilized, as may be desired, such as water passages at each 90° interval about the helical blade structure. However, it is highly desirable to have at least one water passage 26 submerged for each 360° rotation about the helical blade structure, so as to make sure that there is adequate passage of water at all times through the tank.
While the water passages 26 have been illustrated as being rectangular in shape, other shaped passages can be utilized, if desired. For example, wedge shaped passages could be used so that more space is available for water to flow adjacent the perimeter of the helical blade structure than adjacent the auger shaft.
Also, while the auger is illustrated as having helical blade segments 24 A- 24 G, fewer or more blade segments can be used, depending on the length of the tank and other design features of the chiller.
In addition to the water being moveable through the water passages 26 , water is also moveable around the perimeter 40 of the helical blade structure, as illustrated by arrows 44 (FIGS. 5 and 6 ).
As is commonplace for poultry chillers utilizing an auger for urging the birds, such as birds 34 , along the length of the tank, the birds 34 tend to accumulate on one side of the tank due to the frictional contact made between the birds and the bird engagement surfaces 24 ′ of the helical blade structure. Those birds 34 A (FIG. 6) that become positioned adjacent the perimeter 40 of the helical blade structure 23 tend to block the passage of water from the bird engagement surface 24 ′ to the following surface 24 ″ of a blade. This tends to reduce the overall movement of water through the chiller; however, the water passages 26 between the staggered auger blade segments 24 tend to remain open and provide adequate space for the passage of large volumes of water through the chiller.
When the birds 34 , which are driven by the auger 20 in the direction indicated by arrow 46 , move off the edge 48 of one auger blade segment 24 , the urging of the birds along the length of the tank by the auger is intermittently terminated as the birds wait to become engaged by the following auger blade segment. At this moment a water passage 26 passes the birds. This momentary relieving of the urging of the birds by the auger and the movement of the water from about the birds and through the water passage tend to assure that all surfaces of the birds are uniformly contacted and chilled by the cold water and tend to reorient the birds and to reposition the birds with respect to the other birds. All of this tends to expedite the transfer of heat from the birds.
Since the bars 38 of the grills 36 are oriented radially with respect to the helical blade structure 23 , if any bird should become trapped in the bars of a grill, the grill will eventually move above the water line 30 , so that the weight of the bird will tend to move the bird under the influence of gravity down the face of the grill and back into the water. Since the grill is made primarily of radially extending bars, there is substantially no impediment to the weight of the bird moving the bird back into the water and freeing the bird of the grill.
FIG. 7 shows another embodiment of the invention in which the water passages 126 are formed in angled segments 130 of a continuous helical blade structure 132 . The water passages are formed as a series of holes 130 in the angled segment. The holes 134 are in the form of elongated rectilinear slots that extend approximately at a right angle with respect to a radius from the axis of rotation 136 of the auger. The auger rotates in the direction as indicated by arrow 128 .
In both embodiments of the invention, and as schematically illustrated in FIG. 5, the water 30 is recirculated from a first end to a second end of the tank 12 . A drain 52 is positioned at the second end of the tank, and the water is moved from the drain 50 through a pump 54 , from the pump through a heat exchanger 56 generally of the type disclosed in U.S. Pat. No. 5,509,470, and through a conduit 60 , where it is directed to the first end of the tank 12 . Makeup water from a source of fresh water is likewise moved through a pump 62 , heat exchanger 64 , conduit 66 , where it is similarly added to the body of water in the tank 12 . The heat exchangers reduce the temperature of the water to approximately 34° F., or at such other desired temperatures. With this arrangement, fresh water is continuously added to the tank, and a corresponding amount of water is drained away from the tank, thereby assuring the quality of water in the tank.
While the water level 30 is shown above the auger shaft 22 so as to conveniently illustrate the flow of water through the water passages, the normal level of water will be maintained at the level of the auger shaft 22 .
The speed of rotation of the auger can be adjusted as may be desired, but typically runs at one revolution for each four minutes. As it revolves, the auger creates some tumbling action of the birds as the water passages move by the birds. Also, since there is a counter-flow of the chilled water that passes through the water passages formed in the helical blade structure, the water is channeled in a rotating manner through the birds, moving the water flow uniformly through the entire mass of birds, and creating more rapid and uniform chilling action of the birds.
It will be noted from FIGS. 1-3, 5 and 7 that the water passages are aligned at each 180° interval about the helical blade structure. However, it is not critical that the water passages be aligned as illustrated.
When the invention is embodied in, for example, an 8 foot wide tank, the tank has a capacity of 450 lb. per linear foot of birds. For a 10 foot wide tank, the capacity is 650 lb. per linear foot of birds.
The water being delivered to the tank, both recirculated water and fresh water, for a 10 foot tank is 950 GPM through a 50 hp pump. For an 8 foot wide tank, 440 gallons are delivered per minute with a 25 hp pump. This can be increased with the use of the 50 hp pump that typically is associated with a 10 foot diameter tank.
Although preferred embodiments of the invention has been disclosed in detail herein, it will be obvious to those skilled in the art that variations and modifications of the disclosed embodiments can be made without departing from the spirit and scope of the invention as set forth in the following claims.
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Poultry is chilled by moving the birds with an auger in one direction and chilled water in the opposite direction. The auger that moves the birds has a segmented auger blade ( 23 ) formed with a series of blade segments ( 24 ) which overlap one another along the auger shaft ( 22 ) and define water passages ( 26 ) therebetween. A grill ( 36 ) is positioned in the passages. The water passages permit movement of chilled water through the tank, and the offset edges of adjacent auger blade segments, together with the water movement, causes a tumbling and reorientation of the birds as they are chilled and conveyed through the tank.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of U.S. Ser. No. 10/452,322 filed Jun. 2, 2003, which claims the benefit under 35 C.S.C. 119(e) to U.S. Provisional Application No. 60/385,778 filed Aug. 6, 2002.
FIELD OF THE INVENTION
[0002] The present technique relates to the field of expandable devices and methods. More particularly, the technique comprises an expandable device and a method related to an expandable device that has reduced axial shrinkage during radial deformation or expansion thereof.
BACKGROUND OF THE INVENTION
[0003] In the production of sub-terrain fluids, such as oils or natural gas, a variety of expandable devices have been used to cultivate wellbore environments. For example, generally tubular devices, such as expandable liners, expandable sandscreens, well linings and well patches have been employed. These devices may be expandable devices which, under the proper stimuli, transition from a collapsed (small diameter) configuration to an expanded (large diameter) configuration. In many instances, expandable devices comprise a plurality of longitudinal slots or openings that increase in size as the device is expanded (U.S. Pat. Nos. 5,366,012 and 5,667,011). These openings, if so desired, may be configured to permit the flow of desirable production fluids into the interior of the wellbore while simultaneously preventing the ingress of contaminants, such as sand.
[0004] Expandable devices are typically deployed downhole into the wellbore, while in their respective collapsed configurations. In other words, the diameter of the collapsed expandable device is less than that of the wellbore and, as such, the expandable device feeds easily into the wellbore. Once the expandable device is lowered to a desired location within the wellbore, a radial expansion force is applied to drive the device to an expanded configuration. Accordingly, the device may better conform to the interior surface of the wellbore.
[0005] If so desired, expandable devices may be coupled to form a conduit that extends for great distances below the Earth's surface. Indeed, wellbores may extend thousands of feet below the Earth's surface to reach production fluids disposed in subterranean geological formations commonly know as “reservoirs”.
[0006] In many traditional systems (U.S. Pat. Nos. 5,366,012 and 5,667,011), however, an increase in the radial dimension of the device induces a decrease in the axial dimension thereof. In other words, as the device diameter increases, the device length decreases. Accordingly, it may be more difficult to properly position the device into the wellbore. Moreover, a change in axial length may lead to separation or damage of already coupled devices.
[0007] The present invention is directed to overcoming, or at least reducing the effects of one or more of the problems set forth above, and can be useful in other applications as well.
SUMMARY OF THE INVENTION
[0008] The present invention generally relates to a technique for forming an expandable device. The technique comprises forming an expansion compensation portion in an expandable device, e.g., an expandable tubular. The expansion compensation portion substantially limits axial contraction as the expandable device undergoes radial expansion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
[0010] FIG. 1 is a depiction of a wellbore having a plurality of exemplary expandable devices disposed therein.
[0011] FIG. 2 is a depiction of a portion of an embodiment of an expandable device.
[0012] FIG. 3A is a depiction of a portion of an embodiment of an expandable device in a collapsed configuration.
[0013] FIG. 3B illustrates the device of FIG. 3A in an expanded configuration.
[0014] FIG. 4A is a depiction of a portion of another embodiment of an expandable device in a collapsed configuration.
[0015] FIG. 4B illustrates the device of FIG. 4A in an expanded configuration.
[0016] FIG. 5 is an illustration of an embodiment of a cell of an expandable device, the cell being in the collapsed configuration.
[0017] FIG. 6A is a depiction of a portion of another embodiment of an expandable device in a collapsed configuration.
[0018] FIG. 6B illustrates the device of FIG. 6A in an expanded configuration.
[0019] FIG. 7 is a flattened elevational view of an embodiment of an expandable device having a certain pattern of slots.
[0020] FIG. 8 is a cross-sectional view of an expandable device having a cutout portion; and
[0021] FIG. 9 is a depiction of a wellbore having an embodiment of an expandable device disposed therein with an expansion mechanism for expanding the device.
DETAILED DESCRIPTION
[0022] Referring generally to FIG. 1 , an exemplary wellbore environment is illustrated.
[0023] For example, FIG. 1 illustrates a wellbore 20 having at least one lateral branch section 22 . The wellbore 20 may be drilled into the surface of the Earth to facilitate removal of production fluids (i.e. natural gas, oil, etc.) therefrom. In operation, production fluids may enter from the “reservoir” into the wellbore 20 . Subsequently, by employing traditional production methods well known to the skilled artisan, the production fluids may be retrieved to the Earth's surface.
[0024] Disposed along the interior surface of the wellbore 20 may be a casing 24 . The casing 24 may provide structural integrity to the wellbore 20 and can be cemented into location if so desired. Indeed, the casing 24 may extend for thousands of feet into the wellbore 20 as well as into the lateral branch sections 22 .
[0025] At least one expandable device 26 also is disposed within the wellbore 20 . As further discussed below, devices 26 may comprise, casing patches, expandable packers, expandable hangers, expandable liners, expandable casings 24 , expandable sandscreens or expandable control line conduits (i.e. conduits for fiber optic lines, electric lines, hydraulic lines, etc.). As is also further discussed below, devices 26 may be inserted into the wellbore in a collapsed configuration and subsequently expanded. By inserting devices 26 into the wellbore 20 in a collapsed state, a number of advantages may be achieved over traditional systems. For example, a device 26 in the collapsed state may have a diameter less than that of the wellbore it is to be inserted into, and, as such, require less effort for downhole insertion.
[0026] Referring next to FIG. 2 , a section 28 of an expandable device 26 ( FIG. 1 ) is illustrated. The device 26 comprises a wall 30 having a plurality of slots 32 disposed therein. Although the embodiment is illustrated as having slots 32 disposed in the wellbore, the present technique may also be employed with thinned or weakened areas in lieu of the slots 32 . In this embodiment, slots 32 define thick and thin struts 34 and 36 , respectively. The thick and thin struts 34 and 36 may include various expansion compensation portions 38 , the compensation portions 38 being adapted to prevent axial contraction of the device 26 upon radial expansion thereof.
[0027] For example, the compensation portions 38 may comprise spring segments 40 that facilitate axial expansion of the appropriate strut members 36 . Thus, during radial expansion of the device 26 , the spring segment 40 may flex, thereby allowing the strut member 36 upon which it is integrated, to contract or expand as necessary. In other words, the spring segment 40 changes length axially during device expansion, thereby enabling the device 26 , as a whole, to radially expand without substantial axial contraction thereof. In some embodiments, the spring segment 40 may undergo both elastic deformation as well as plastic deformation.
[0028] Under expansion loads, relatively thick struts 34 remain essentially undeformed and, as such, maintain the overall axial length of the device 26 . Contemporaneously, however, the expansion loads applied to the thin members 36 induce axial contraction lengthening thereof, thereby facilitating radial expansion of the device 26 . Moreover, the spring segments 40 may also provide additional flexibility to the device 26 thereby reducing the expansion forces necessary to drive device 26 to its expanded configuration.
[0029] Additionally, compensation portions 38 may comprise rotational segments 42 disposed along respective strut members 36 . Rotational segments 42 also substantially reduce axial contraction of the device 26 ( FIG. 1 ), as a whole, upon radial expansion thereof. Indeed, during expansion, the exemplary rotational segments 42 , as well as the relatively thin strut 36 within which it is disposed, tend to rotate whereas the relatively thick struts 34 retain their original configuration. This torsional deformation of the thin struts 36 , being either plastic or elastic, allows the device 26 to radially expand while the rigid thick struts 34 substantially maintain the original axial length of device 26 . The rotational segments 42 may have tapering portions, rounded portions or other variations in the thickness of the strut 36 to optimize the properties of the rotational segments 42 .
[0030] Disposed between adjacent, relatively, thick and thin struts 34 and 36 may be hinge portions 44 . In the exemplary embodiment, hinge portions 44 facilitate the pivotal movement of the strut members 34 and 36 with respect to one another. The hinge portions 44 may be thinned sections of wall 30 disposed at the intersection of the respective ends of the struts 34 and 36 . The thinner hinge portions 44 reduce the overall expansion force required to drive the exemplary device from a collapsed to an expanded configuration.
[0031] Various features of the expandable device 26 , such as the strut members 34 and 36 , compensation portions 38 as well as the corresponding slots 32 may be formed by a number of processes. For example, these features may be formed by targeting a high-pressure water jet stream against the stock material from which the device 26 is to be formed. The water pressure carves out desired features on to the device. In a similar vein, these features may be carved by laser-jet cutting the stock material. Additionally, the features may be formed by a stamping process. In this process, the flat stock material is placed into a press which then stamps the features into the material. Once stamped, the material may be rolled into a rounded or tubular form. To ensure structural integrity of the stamped material, the features may be at least as wide as the thickness of the material being stamped.
[0032] Referring next to FIGS. 3A and 3B , an alternate embodiment of the present technique is illustrated. Particularly, FIGS. 3A and 3B illustrate one embodiment of section 28 of device 26 in the collapsed configuration and expanded configuration respectively. Section 28 comprises compensation portions 38 , such as spring segments 40 and rotational segments 42 . Again, as the device 26 is taken from the collapsed to expanded configuration, the expansion forces may induce deformation of the thin strut 36 . However, the relatively thick strut 34 , because of its size, resists deformation. Accordingly, the thin struts 36 facilitate radial expansion of the device while the thick struts 34 , concurrently, maintain the axial length of the device 26 .
[0033] Referring next to FIGS. 4A and 4B , another embodiment of the present technique is illustrated. In the collapsed state, as illustrated in FIG. 4A , section 28 comprises thick and thin struts 34 and 36 , respectively, traversed by a linking member 46 . The linking member is connected to the respective struts 34 and 36 by hinge portions 44 . The linking member 46 , in conjunction with the thin and thick struts 34 and 36 , respectively may define parallelogramic slots 32 .
[0034] During radial expansion of device 26 to the expanded configuration illustrated in FIG. 4B , the linking member 46 pivots about hinge portions 44 . The linking members 46 may pivot such that the thick and thin struts 34 and 36 remain parallel to one another. Additionally, similar to the above embodiments, compensation portions 38 facilitate radial expansion of the device while concurrently maintaining the overall length of the device. In the exemplary embodiment, the spring segments 40 may deform thereby facilitating radial expansion of the device without substantially affecting axial length. Moreover, the linking members 46 may be configured to elastically or plastically deform, thereby assisting in the radial expansion of the device 26 .
[0035] Referring next to FIG. 5 , an expandable cell 48 of an expansion section 28 in a collapsed configuration is illustrated. In this embodiment, a relatively thin bending connector 50 traverses adjacent thick struts 34 . The bending connector 50 may comprise folding portions 52 and spring segments 40 . During radial expansion, the thick struts 34 distance themselves from one another, and resultantly, the folding portions 52 begin to unfold. As the radial expansion continues, bending connector 50 may undergo axial deformation. Indeed, the spring segments 40 of the bending connector 50 may undergo elastic or plastic deformation to facilitate the radial expansion of the device 26 without axial contraction thereof. The bending connector 50 maintains the thick struts 34 generally parallel to one another during the expansion process.
[0036] Referring next to FIGS. 6A and 6B , another embodiment of the present device is illustrated in collapsed and expanded configurations, respectively. In this embodiment, section 28 comprises a series of linking members 46 and thin struts 36 which, in combination, define three separate slot shapes 32 a , 32 b , and 32 c . The linking members 46 as well as the thin struts 36 may comprise spring portions as well as rotation portions, e.g. spring portions 40 and rotation portions 42 . Spring portions 40 and rotation portions 42 serve as expansion compensators radial expansion of the device to prevent shortening the original axial length of device 26 . Referring to FIG. 7 , the slot pattern of FIGS. 6A and 6B is illustrated as a flat sheet. Advantageously, tubulars may be formed from flat sheets which are subsequently bent into a cylindrical shape.
[0037] Returning to FIG. 1 , the present technique may be employed in many types of devices 26 employable within a wellbore 20 . For example, the device 26 may be a casing patch 54 . If, for illustrative purposes, a hole were to develop in the casing 24 , the structural integrity of the casing 24 may be affected. Accordingly, a casing patch 54 may be deployed to the location of the hole in the collapsed configuration. Subsequently, the casing patch 54 may be expanded to secure the casing patch 54 to the damaged portion of the original casing 24 . The device may also comprise an expandable liner 56 for the multilateral junctions. Again, the liner 56 may be deployed to the desired location and subsequently expanded for securing at such location. The device 26 may also comprise an expandable packer 58 deployed, for example, to isolate portions of a wellbore 20 . In operation, the packer 58 , similar to other expandable devices described herein, may be deployed to a desired location and subsequently expanded. Yet another embodiment of device 26 is an expandable sand-screen 60 . Sand-screens 60 may be placed into the wellbore 20 to prevent the ingress of sand from the interior wellbore surface while concurrently permitting the ingress of desirable production fluids. Lastly, although not exhaustively, the device 26 may comprise an expandable hanger 62 . In operation, the expandable hanger 62 facilities, for example, the coupling of casing or lining segments together. Indeed, the hanger 62 may allow casings or linings to extend for hundreds of feet into the wellbore. Again, each of the exemplary devices 26 discussed above may be formed, at least in part, of the expandable devices of the present technique.
[0038] Referring to FIG. 8 , a cross-sectional view of an expandable device 26 having a cutout portion 64 is illustrated. The cutout portion 64 may be employed as a passageway for the routing of control lines 66 therethrough. Additionally, intelligent completions equipment, monitoring devices, fiber optic lines and other equipment may be positioned in the cutout portion 64 . As illustrated, cutout portion 64 lies in a generally axial direction along the exterior of device 26 , although the cutout can be formed along an interior surface or entirely within the wall of device 26 .
[0039] Referring to FIG. 9 , a cone 68 is illustrated as expanding the device 26 . A variety of expansion devices may be employed and cone 68 is just one option. Once the expandable device 26 has been placed at the appropriate position in the wellbore, cone 68 is then pulled or pushed therethrough. A tapered end 70 of cone 68 may easily be fed into the device 26 when in its collapsed configuration. As the cone 68 progresses further, the widening diameter of the cone abuts against the interior surface of the device and imparts the necessary radial forces for expansion.
[0040] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Indeed, the present technique may be employed in any number of oilfield applications such as umbilical or conduit repairs for example.
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The present system and method comprises an expandable device for use in wellbores. In one embodiment, the present device comprises a plurality of slots disposed within the device. The slots define expansion compensation portions, wherein the compensation portions facilitate radial expansion of the device while concurrently maintaining essentially constant the axial length of the device. The present technique also comprises a method of forming the device in accordance therewith.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/129,332 filed on Jun. 19, 2008, the complete disclosure of which, in its entirety, is herein incorporated by reference. This application is also a continuation-in-part of U.S. patent application Ser. No. 11/253,609 filed on Oct. 20, 2005, the complete disclosure of which, in its entirety, is also herein incorporated by reference.
GOVERNMENT INTEREST
[0002] The embodiments described herein may be manufactured, used, and/or licensed by or for the United States Government without the payment of royalties thereon.
BACKGROUND
[0003] 1. Technical Field
[0004] The embodiments herein generally relate to microelectronic devices and fabrication methods and, more particularly, to gallium nitride semiconductor devices and fabrication methods thereof.
[0005] 2. Description of the Related Art
[0006] Gallium nitride is being widely investigated for microelectronic devices including but not limited to transistors, field emitters, and optoelectronic devices. It will be understood that, as used herein, gallium nitride also includes alloys of gallium nitride such as aluminum gallium nitride, indium gallium nitride and aluminum indium gallium nitride.
[0007] A major problem in fabricating gallium nitride-based microelectronic devices is the fabrication of gallium nitride semiconductor layers having low defect densities. It is known that contributors to defect density are the lattice and thermal mismatch between the substrate and the gallium nitride layer. Accordingly, although gallium nitride layers have been grown on sapphire substrates, it is possible to reduce defect density by growing gallium nitride layers on aluminum nitride buffer layers which are themselves formed on silicon carbide substrates.
SUMMARY
[0008] In view of the foregoing, an embodiment herein provides a gallium nitride semiconductor device comprising: a first gallium nitride layer comprising a plurality of gallium nitride columns etched into the first gallium nitride layer and a first dislocation density; and a second gallium nitride layer that extends adjacent to the side walls and over the gallium nitride columns and comprises a second layer of regions with low and high dislocation density.
[0009] The first gallium nitride layer may be vertically aligned over the second gallium nitride layer. Furthermore, each of the plurality of gallium nitride columns may be of width between about 1 μm and about 100 μm wide. In addition, each of the plurality of gallium nitride columns may be separated by a distance in the range of about 1 μm to about 100 μm, but is not necessarily limited to this range. Additionally, the second gallium nitride layer may be grown using a lateral epitaxial overgrowth. In addition, the on the second gallium nitride layer a Schottky contact may be fabricated comprising, but not limited to 500 Å of Ni and approximately 1,500 Å of Au.
[0010] In addition, an embodiment herein provides a method of fabricating a gallium nitride semiconductor layer, the method comprising: masking an underlying gallium nitride layer with a mask that comprises an array of columns therein; and growing the underlying gallium nitride layer through the columns and onto the mask using metal-organic chemical vapor deposition pendeo-epitaxy to thereby form a pendeo-epitaxial gallium nitride layer coalesced on the mask to form a continuous pendeo-epitaxial monocrystalline gallium nitride semiconductor layer.
[0011] In addition, at least one semiconductor device may be formed in the pendeo-epitaxial gallium nitride semiconductor layer. The growing process may comprise metal-organic chemical vapor deposition pendeo-epitaxy of at least triethylgallium at 13-39 μmol/min. Furthermore, the pendeo-epitaxial gallium nitride semiconductor layer may be grown in growth temperatures between approximately 1,000° C. and 1,120° C. Moreover, the pendeo-epitaxial gallium nitride semiconductor layer may be grown with a V:III ratio of 2600. Additionally, the pendeo-epitaxial gallium nitride semiconductor layer may be grown with a chamber pressure of approximately 100 Torr.
[0012] Furthermore, an embodiment herein provides a semiconductor device comprising a substrate; a plurality of gallium nitride columns coupled to the substrate; a plurality of gallium nitride trenches, coupled to the substrate, wherein each of the plurality of gallium nitride columns are positioned alternate with each of the plurality of gallium nitride trenches; a low-defect density gallium nitride layer formed over the gallium nitride columns; and an active region including, but not limited to, a source, a drain, and a gate, wherein the active region is vertically aligned over the low-defect density layer. The source and the drain may comprise an ohmic contact and the gate may comprise a Schottky contact. Additionally, each of the plurality of gallium nitride columns may comprise at least two sidewalls and a post, and each of the at least two sidewalls is preferably directly coupled to a gallium nitride trench and the post. The substrate may comprise at least one of sapphire and gallium nitride. Furthermore, the plurality of gallium nitride columns and the plurality of gallium nitride trenches may be etched from a gallium nitride layer using at least one of front and backside photolithography. Moreover, the low-defect density gallium nitride layer may be formed over the gallium nitride columns using pendeo epitaxy. Also, the low-defect density gallium nitride layer may comprise a first defect density region formed over each of the plurality of gallium nitride columns and a second defect density formed over each of the plurality of gallium nitride trenches, and the second defect density region is preferably higher than first defect density region.
[0013] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0015] FIG. 1 illustrates a schematic diagram of a semiconductor device according to an embodiment herein;
[0016] FIG. 2 illustrates a schematic diagram of a column and trench according to an embodiment herein;
[0017] FIG. 3 illustrates a schematic diagram of a column and trench with lateral GaN growth according to an embodiment herein;
[0018] FIG. 4 is a flow diagram illustrating a method according to an embodiment herein;
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0020] The embodiments herein provide optimized metal-organic chemical vapor deposition (or “MOCVD”) growth parameters to produce a low-defect density pendeo-epitaxial gallium nitride material within a large area. Referring now to the drawings, and more particularly to FIGS. 1 through 6 , where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0021] Gallium nitride (or “GaN”) is a wide band-gap semiconductor having superior material characteristics for many electronics applications, compared to commonly used semiconductors such as silicon (or “Si”) and gallium arsenide (or “GaAs”). GaN is a material that offers high-power, high frequency, high temperature applications and, performs much greater in these areas when compared to Si and much greater when compared to GaAs. Benefits of GaN-based devices are numerous and are beneficial to devices such as laser diodes, light emitting diodes, and p-n junctions, where each device shows significant improvement in operational characteristics such as lifetime, leakage current, and internal quantum efficiency when the devices are fabricated on GaN with a low-defect density region grown via selective area epitaxy.
[0022] However, inadequate long-term device reliability is currently a critical issue that must be solved to enable the insertion of GaN devices and integrated circuits into systems. Problems with long-term device reliability are related to a number of failure mechanisms that arise from degradation of the material properties within the GaN layers, and at the interfaces between GaN and other materials. Examples of structural defects that reduce the long-term device reliability include dislocations, stacking faults, microcrystalline grains, and grain boundaries. One approach for reduction of the defect density in GaN material is via selective area epitaxy; a common name for both the lateral epitaxial overgrowth (LEO) and the pendeo-epitaxial (PE) growth techniques. Methods of forming lateral gallium nitride layers that extend from an underlying gallium nitride layer are described in U.S. Pat. No. 6,051,849, the complete disclosure of which is herein incorporated by reference in its entirety. The pendeo-epitaxial approach for growth of GaN utilizes the lateral epitaxial growth mechanism, enabling the GaN material to grow laterally from the sidewalls of etched GaN rectangular columns with two to four orders of magnitude lower dislocation density than conventional growth techniques. Further details about the LEO and the PE growth techniques are discussed in Zheleva, T. et al., “Pendeo-Epitaxy—A New Approach for Lateral Growth of Gallium Nitride Films,” Journal of Electronic Materials, 28, L5-L8 (1999), the complete disclosure of which, in its entirety, is herein incorporated by reference:
[0023] FIG. 1 shows a semiconductor device 1 ; for example, a High Electron Mobility Transistor (or “HEMT”) semiconductor device 1 . Semiconductor device 1 includes an active region 20 a which is vertically aligned over a low-defect density GaN region described below. The active region in FIG. 1 includes portions 10 a of the source 10 , portions of the drain 15 a of the drain 15 , and portions of the gate 20 a, specifically the fingers of the gate 20 . GaN columns 5 are used to grow the low-defect density layer, as described below. While not shown in FIG. 1 , source 10 and drain 15 include Ohmic contacts and are optionally formed between the low-defect density GaN layer and Ti/Al. In addition, gate 20 includes a Schottky contact (not shown) and is optionally formed between the low-defect density GaN layer and Ni/Au.
[0024] FIGS. 2 and 3 , with reference to FIG. 1 , illustrate in further detail the pendeo-epitaxy growth of low-defect density GaN layer 9 around the GaN columns 5 . An underlying GaN layer is grown on a substrate 25 . Substrate 25 may include sapphire or gallium nitride or Si or GaAs or other types of substrates. Substrate 25 may also include 6H-SiC and optionally an aluminum nitride buffer layer (not shown). The crystallographic designation conventions used herein are well-known to those having skill in the art, and need not be described further. In addition, the fabrication of substrate 25 is well-known to those having skill in the art and need not be described further. Fabrication of silicon carbide substrates are described, for example, in U.S. Pat. No. 4,865,685 to Palmour; Re 34,861 to Davis et al.; U.S. Pat. No. 4,912,064 to Kong et al., and U.S. Pat. No. 4,946,547 to Palmour et al., the complete disclosure of which, are herein incorporated by reference in their entireties.
[0025] For example, the underlying GaN layer 9 may be between approximately 1.0 and 2.0 μm thick, but not limited to this thickness. In addition, the underlying GaN layer 9 may be grown at approximately 1,000° C. on a high temperature (1,100° C.) aluminum nitride buffer layer that is deposited on a 6H-SiC substrate in a cold wall vertical and inductively heated metalorganic vapor phase epitaxy system using triethylgallium at approximately 26 μmol/min, ammonia at approximately 1,500 sccm and approximately 3,000 sccm hydrogen diluent. Additional details of this growth technique may be found in Weeks, T. et al., “GaN Thin Films Deposited Via Organometallic Vapor Phase Epitaxy on α(6H)-SiC(0001) Using High-Temperature Monocrystalline AlN Buffer Layers,” Applied Physics Letters, Vol. 67, No. 3, Jul. 17, 1995, pp. 401-403, the complete disclosure of which, in its entirety, is herein incorporated by reference. In addition, other substrates, with or without buffer layers may be used in accordance with the embodiments herein.
[0026] Still referring to FIG. 2 , the underlying GaN layer 9 includes a plurality of GaN columns 5 etched therein. Each column 5 includes sidewalls 7 and post 6 . It will be understood by those having skill in the art that sidewalls 7 may be thought of as being defined by a plurality of spaced apart columns 5 . Sidewalls 7 may also be thought of as being defined by a plurality of trenches 8 , also referred to as “wells” in the underlying GaN layer 9 . Methods of forming gallium nitride layers into trenches are described in U.S. Pat. No. 6,265,289 the complete disclosure of which is herein incorporated by reference in its entirety. Sidewalls 7 may also be thought of as being defined by a series of alternating trenches 8 and columns 5 . It will be understood that posts 6 and trenches 8 that define sidewalls 7 may be fabricated by selective etching and/or selective epitaxial growth and/or other suitable techniques. For example, columns 5 may be etched using front and backside photolithography. Moreover, it will also be understood that sidewalls 7 need not be orthogonal to substrate 25 , but rather may be oblique thereto. Finally, it will also be understood that although sidewalls 7 are shown in cross-section in FIG. 2 , posts 6 and trenches 8 may define elongated regions that are straight, V-shaped or have other shapes. While not shown in FIGS. 2 and 3 , trenches 8 may extend into an optional buffer layer and into substrate 25 , so that subsequent GaN growth occurs preferentially on sidewalls 7 rather than on the trench floors. In other embodiments, trenches 8 may not extend into substrate 25 , and also may not extend into an optional buffer layer, depending, for example, on the geometry of trenches 8 and the lateral versus vertical growth rates of the GaN (as discussed below).
[0027] Referring now to FIG. 3 , sidewalls 7 of the underlying GaN layer 9 are laterally grown to form a lateral GaN layer 9 formed in trenches 8 . Lateral growth of GaN may be obtained at approximately 1,000 to 1,120° C. and 45 Torr. The precursors trimethyl gallium (TMG) at 13-39 μmol/min and NH 3 at 1,500 sccm may be used in combination with a 3,000 sccm H 2 diluent. If GaN alloys are formed, additional precursors of aluminum or indium, for example, may also be used. As used herein, the term “lateral” refers to a direction that is orthogonal to sidewalls 7 . It will also be understood that some vertical growth on posts 6 may also take place during the lateral growth from sidewalls 7 . As used herein, the term “vertical” denotes a directional parallel to sidewalls 7 . At different temperatures, however, the shape of a grown lateral GaN layer 30 changes. As shown in FIG. 3 , lateral GaN layer 30 is formed at approximately 1,060° C. Lateral GaN layer 35 is formed at approximately 1,080° C. Finally, lateral GaN layer 40 is formed at approximately 1,100° C. While not shown in FIG. 3 , optimal lateral growth of a low-defect density GaN layer occurs at approximately 1,120° C.
[0028] In addition, the continued growth of the lateral GaN layer 40 causes vertical growth onto the underlying GaN layer 9 , specifically onto columns 5 . Growth conditions for vertical growth may be maintained and characterized as was described in connection with lateral growth.
[0029] While not shown in FIG. 3 , low-defect density pendeo growth is allowed to continue until the lateral growth fronts coalesce in trench 8 with an adjacent column (not shown) to form a continuous low-defect density layer in the trenches 8 . In one example embodiment, the total growth time of a continuous low-defect density pendeo GaN layer takes approximated 60 minutes. As shown in FIG. 1 , semiconductor device 1 (which includes source 10 , drain 15 , and gate 20 ) may then be vertically aligned over the low-density GaN layer. In addition, semiconductor structures may also be formed in a vertical GaN layer.
[0030] As discussed above, a lateral GaN layer 40 coalesces to form a continuous lateral GaN semiconductor layer in the trenches (e.g., trench 8 ). The dislocation densities in the underlying GaN layer 9 generally do not propagate laterally from sidewalls 7 with the same density as vertically from the underlying GaN layer 9 used to form column 5 . Accordingly, low-defect density lateral GaN layer 40 may form device quality GaN semiconductor material. Thus, semiconductor device 1 may be formed in the lateral gallium nitride semiconductor layer 40 via a mask (not shown).
[0031] In addition, to characterize the electrical properties of the low dislocation density pendeo-grown GaN material and the conventional (non-pendeo) GaN material, Ohmic and Schottky contacts (not shown) may be fabricated on semiconductor 1 , using standard lift-off photolithography on two types of material. The Ti (140 Å)/Al (2,200 Å) Ohmic contacts are annealed at approximately 800° C. for 60 seconds prior to the Schottky contact metallization. The Ni (500 Å)/Au (1,500 Å) Schottky contacts are prepared via e-beam deposition. Current-voltage (I-V) characteristics are measured between −10 V and 5 V after preparation.
[0032] FIG. 4 , with reference to FIGS. 1 through 3 , describes an exemplary method for growing a low-defect density GaN layer. At step 50 , a first GaN layer 9 is grown using conventional metal-organic chemical vapor deposition (or “MOCVD”) techniques. Desirably, the first GaN layer 9 is grown to approximately 1.5 μm depth. The crystallographic designation conventions used herein, and specifically conventional MOCVD growth techniques, are well-known to those having skill in the art, and need not be described further. Next, at step 55 , a plurality of pendeo-growth columns 5 and trenches 8 are etched into the first GaN layer 9 . Optionally, the pendeo-growth columns 5 are etched into the first GaN layer 9 using front and/or backside photolithography. Finally, at step 60 , pendeo-epitaxial GaN is grown using MOCVD.
[0033] During step 60 , optimal pendeo-epitaxial GaN growth is obtained when using the following MOCVD growth parameters: growth temperature between 1,060° C.-1,120° C., ammonia to triethylgallium (V/III ratio 1,200 to 3,600), chamber pressure to grow the GaN is between 1.07×10 4 Pascal (or 80 Torr) to 1.6×10 4 Pascal (or 120 Torr)), and mask geometry, to etch the pendeo-growth columns, that include a column width between approximately 2 μm or 3 μm and a trench width, as situated between a pair of columns 5 , is either approximately 12 μm, 14 μm, or 20 μm. These growth parameters are used to optimize the lateral to vertical growth rate at a given pattern geometry (e.g., the gate 20 shown in FIG. 1 ). In addition, a broad range of material characterization techniques are employed to establish the optimized growth and device processing parameters.
[0034] The structural quality of the GaN material is commonly characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), spectroscopic cathodoluminescence (CL), and etch pit density (EPD) measurements. In addition, in determining the distribution of dislocations throughout the material grown is determined by etching with molten potassium hydroxide (KOH) at approximately 450° C. for approximately 5 minutes, to expose the areas with threading dislocations that have a higher etch rate than dislocation-free areas.
[0035] An optimal low-defect density GaN layer, with the highest lateral-to-vertical growth rate ratio, is achieved at growth temperatures of approximately 1,100° C. to 1,120° C., V:III ratio of 2600 and chamber pressure of approximately 100 Torr. Under these conditions, the pendeo-epitaxial “wing” (or lateral growth area for each pendeo-growth column) areas of dimensions 7 μm×100 μm, corresponding to lateral growth, are nearly free of dislocation-related etch-pits. AFM imaging of the etched GaN stripe grown via pendeo-epitaxy, with dislocations revealed as etch-pits having densities of 8.95±0.6×10 8 and 2.8±3×10 6 cm −2 for the non-pendeo (vertical growth) and the pendeo (lateral growth) regions, respectively. Areas of pendeo-epitaxial GaN investigated by AFM as large as 5 microns by 10 microns are consistently observed to be free of dislocations. The root-mean-squared (RMS) surface roughness of the non-pendeo and the pendeo GaN regions is 1.38±0.9 nm and 0.3±0.08 nm, respectively. Thus, the dislocation density goes through drastic reduction of 320 times, while the surface roughness is reduced nearly five times.
[0036] Further characterization of the structural and optical properties of the pendeo and non-pendeo GaN material according to the embodiments described herein are performed via cathodoluminescence (CL) imaging and spectroscopy. The CL intensity is seen to be distinctly higher from the low defect density pendeo GaN regions than from the non-pendeo material in the center of each GaN column 5 (shown in FIG. 1 ). The CL intensity is also very low from trenches 8 between the GaN columns 5 , as shown in FIGS. 2 and 3 . This difference is attributed to the presence of a higher density of non-radiative recombination centers in the non-pendeo material, associated with impurities and point defects clustered around the dislocation cores. Local areas of lower CL intensity (dark contrast), with a highly non-uniform spatial distribution, are also observed near the outer edges of the pendeo-grown regions adjacent to trenches 8 between columns 5 . These localized “dark contrast” areas arise from the extended defects, mostly threading dislocations, that propagate initially vertically from the center of columns 5 and then laterally to the outer edges of columns 5 . In FIG. 5 , with reference to FIGS. 1 though 4 , CL spectra in the 1.5 eV to 3.7 eV range are shown for pendeo growth 70 and non-pendeo growth 75 , and are acquired from the center region 77 (e.g., vertical growth about the pendeo-growth columns 5 ) and the wing region 79 (e.g., lateral growth from the pendeo-growth columns 5 ). There is over one order of magnitude increase in the PL intensity of the near band edge or excitonic peak 80 (in the 3.2 eV to 3.5 eV range), from the pendeo-GaN region (shown as 80 a ), as compared to the non-pendeo region (shown as 80 b ). Interestingly, band 81 (2.0 eV to 2.3 eV) is stronger for the pendeo-GaN region (shown as 81 a ), by about a factor of two, than the non-pendeo region (shown as 81 b ). On the other hand, band 82 (2.65 eV to 2.9 eV) is relatively strong for the non-pendeo region (shown as 82 b ), while the pendeo-GaN region (shown as 82 a ) does not show a distinct peak in band 82 . Band 81 and band 82 in GaN are attributed to impurities or (impurity—point defect) complexes. In particular band 81 is ascribed to deep donor—acceptor recombination involving C and O impurities, or to (gallium vacancy)—(C or O impurity) complexes acting as deep acceptors. Band 82 is ascribed to deep donor—acceptor recombination involving C impurities, or to Zn deep acceptors. Since the intensity of band 81 is reduced by a factor of two in the high dislocation density non-pendeo regions 81 b (as compared to the pendeo-grown region 81 a ), it suggests that band 81 is quenched by the same non-radiative recombination centers, associated with dislocations, that give rise to quenching of the exciton band in the non-pendeo regions. In addition, since a distinct band 82 occurs only in the non-pendeo region 82 b, it suggests that the luminescence centers corresponding to ban 82 (impurities and point defects) occur near the dislocation cores.
[0037] As mentioned previously, the low-defect density GaN layer 9 is used to fabricate Schottky Ni (500 Å)/Au (1500 Å) contacts such that the Schottky diodes are aligned with the low defect density pendeo-GaN regions. FIG. 6 illustrates the current-voltage characteristics of Schottky diodes fabricated on both pendeo region (shown as 85 ) and non-pendeo GaN region (shown as 86 ) are measured between −10 V and 5 V. The ideality factor, n, describes how closely the Schottky diode follows thermionic emission theory. A perfectly ideal diode has n=1.0. In practicality, ideality factors are greater than unity. Schottky contacts with low ideality factors indicate an improved metal-semiconductor interface, while higher ideality factors indicate current transport mechanisms other than thermionic emission. All diodes fabricated on the pendeo epitaxial material, as discussed in the embodiments described herein, display near-ideal characteristics under forward bias with an average ideality factor of n=1.32±0.04. Conversely, Schottky diodes on non-pendeo material display non-ideal characteristics with an average ideality factor of 1.73±0.35. While the Schottky diodes on the pendeo-GaN material display close to ideal linear behavior, the Schottky diodes on the non-pendeo columns 5 all display a characteristic “knee” (shown as 87 ) at low forward voltage that is typical of two barrier heights acting in parallel. These phenomena occur when “patches” of inhomogeneous Schottky barrier height materials are present at the metal-semiconductor interface. In addition, at a −2V reverse bias the average leakage current is measured to be 6.7±2.8×10 −5 A and 2.1±6.8×10 −4 A for the pendeo and non-pendeo material, respectively. For both cases of the leakage current, the large standard deviation can be explained by the large differences in the leakage current, likely due to the proximity to an extended defect such as a threading dislocation core. These variations can be over an order of magnitude from the lowest value to the highest value. The larger standard deviations for the non-pendeo material are likely due to the large variation in ideality factors and leakage currents. Overall, the diodes on the pendeo-epitaxial material show more uniformity in terms of ideality and leakage current, due to the lower defect density material. The reduction of the leakage current is another indication of the improved electrical properties of the pendeo-epitaxial material.
[0038] The optimization of the MOCVD growth parameters described herein produce low-defect density pendeo-epitaxial GaN material within a large area (7 μm×100 μm). Devices fabricated on the pendeo-epitaxial GaN, such as Schottky diodes, show nearly two orders of magnitude reduction in leakage current and approximately 25% improvement in ideality factor, as compared to diodes of similar structure fabricated on non-pendeo material.
[0039] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
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A low-defect gallium nitride structure including a first gallium nitride layer comprising a plurality of gallium nitride columns etched into the first gallium nitride layer and a first dislocation density; and a second gallium nitride layer that extends over the gallium nitride columns and comprises a second dislocation density, wherein the second dislocation density may be lower than the first dislocation density. In addition, a method for fabricating a gallium nitride semiconductor layer that includes masking an underlying gallium nitride layer with a mask that comprises an array of columns and growing the underlying gallium nitride layer through the columns and onto said mask using metal-organic chemical vapor deposition pendeo-epitaxy to thereby form a pendeo-epitaxial gallium nitride layer coalesced on said mask to form a continuous pendeo-epitaxial monocrystalline gallium nitride semiconductor layer.
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TECHNICAL FIELD
The present invention relates to a down feather sheet or membrane as well as the method of fabricating same.
BACKGROUND ART
Down feather sheets are usually provided by forming a pouch, which may be of rectangular outline or patterned shape, by stitching together two fabric sheets and leaving an unseamed area wherein down feathers may be inserted within the pouch. The unseamed area is then sewn to trap the down feathers in the pouch. These feathers are then distributed within the pouch by shaking the pouch to displace the feathers substantially evenly therein. Cross-stitched lines are then formed across the fabric sheets whereby to trap the down feathers therebetween.
One of the major problems with this method of fabrication is that the down feathers are often unevenly distributed within the pouch due to the fact that in the manufacturing process the pouches are formed with fabrics which conceal the down feathers within the pouch and this often results in areas of the pouch not having enough down feathers and others having too many. Accordingly, the product does not have even insulating properties and its appearance is not suitable for use in fabricating a garment. Furthermore, by making many stitch lines across the fabric, cold spots are developed and the stitch lines where there is no insulation. The process is also very labor intensive and cannot be adapted to automatic fabrication. Another problem associated with down feathers is their uneven color. When these are inserted into a pouch formed by thin, light colored, fabrics, the down feathers within the pouch will give an uneven color appearance to the light colored fabric.
SUMMARY OF INVENTION
It is a feature of the present invention to provide a method of fabricating a down feather sheet or membrane which substantially overcomes the above-mentioned disadvantages of the prior art.
Another feature of the present invention is to provide a down feather sheet or membrane which is comprised of a substantially homogeneous distribution of down feathers which are retained together in a sheet form by a binder such as a chemical binding agent.
According to the above features, from a broad aspect, the present invention provides a method of fabricating a down feather sheet which comprises the step of forming a sheet of down feathers having been treated to retain a homogeneous form.
Another feature of the present invention is to provide a down feather sheet which comprises a substantially homogeneous distribution of down feathers retained together in sheet form by a binding means.
Another feature of the present invention is to provide a down feather sheet and a method of fabricating same wherein the binding means is a chemical binding agent which causes the feathers to adhere to one another.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a down feather sheet constructed in accordance with the present invention;
FIG. 2 is a schematic illustration showing a method of fabricating the down feather sheet using a liquid or powder binding agent;
FIG. 3 is a schematic view similar to FIG. 2 but wherein the method comprises the fabrication of patterned down feather sheets and wherein the down feathers can be colored;
FIG. 4 is a perspective view showing a dye-cut pattern down feather sheet; and
FIGS. 5 and 6 are schematic illustrations showing that the down feather sheet can be fabricated in roll form or in stacked sheet form.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and more particularly to FIG. 1, there is shown generally at 10 the down feather sheet of the present invention. It consists of a substantially homogeneous distribution of down feathers 11 retained together in sheet form by a binder means which will be described later. The down feather sheet 10 may be produced in roll form as illustrated at 12 in FIG. 5 or in sheet form, which may be stacked one on top of the other, as illustrated at 13 in FIG. 6.
Referring now to FIG. 2, there is shown one method of fabricating the down feather sheet 10 of the present invention. The method consists of providing a conveyor support surface, herein shown as an endless belt 14 supported between rollers 15. A supply of down feathers 11 is disposed within a hopper 16 at a feed end 17 of the conveyor and the feathers are deposited on the top surface 18 of the endless belt 14 at the feed end 17. The distribution of the feathers 11 is controlled by a rotor 19. A shroud, not shown, could be installed between the discharge end of the hopper 16 and the conveyor to shield the feathers against air currents, etc.
As can be seen a substantially even layer of down feathers 11 is disposed on the top surface 18 of the conveyor 14 and is displaced towards a binder applicating station 20 where a liquid or powder binder is applied to the down feathers. An agitator mechanism 21 may also be provided under the endless belt 14 at the binder application station whereby to cause the binder to mix thoroughly with the feathers.
After the binder application station 20 the layer of down feathers is fed under a heater or dryer station 22 where the binding agent is caused to set whereby to bind the feathers together. At the outlet of the heater or dryer station 22, the sheet is of substantially homogeneous form and can then be slit by a slitter 23 whereby to produce down feather sheets, as illustrated in FIG. 6, which may be disposed on a support platform 24 to produce stacks of sheets 13 as shown in FIG. 6. A sheet transfer mechanism 25 disposes the sheets in stack form.
Referring now to FIG. 3, there is shown a further method of producing the down feather sheet 10 of the present invention. As hereinshown the down feathers are retained in even distribution on the conveyor belt 14 by an electrostatic field or charge which extends to at least the dryer station 22'. The electrostatic field is produced by a voltage source 26 which creates an electrostatic field between the top side and bottom side of the endless belt 14. As hereinshown the binder application station 20' is comprised of jet nozzles 27 which emit a spray of binder onto the down feathers. This binder is then dried at the dryer station 22'. A dye applicator 28 may also be provided if it is desirable to dye the down feather sheet 10 a certain color. The sheet may also be cut into a pattern by a dye-cut press 29 to produce the dye-cut down feather sheets 30 as illustrated in FIG. 4
The thickness of the feathers deposited on the belt may be regulated by the speed of displacement of the endless belt or else the speed of operation of the rotor 19 which dispenses down feathers from the hopper. The binding agent, when in powder form, may also be mixed with feathers in the hopper 16. Accordingly, it is not necessary to use the agitator 21.
It is within the ambit of the present invention to cover any obvious modifications of the examples of the preferred embodiment described herein. It is also readily apparent that with the process of manufacturing of the present invention down feather sheets of predetermined thickness and density may be produced by controlling the output of the hopper or the velocity of the endless belt and this can be done by automatic control means. Sensors may also be provided along the conveyor to detect the density and thickness of the down feather sheets. Further sensors may also be provided at the outlet end of the sheet to operate the slitter or the dye-cut press and to regulate the density of the coloration of the sheet should a dye be applied thereto. As previously described the binder may be a liquid powder or fibers added to the down feathers but it may also be provided in vapor spray or as a gas spray provided it has binding properties associated therewith. Although an automatic layering of the down feathers on the endless belt is described, this could also be done manually but to obtain a more even consistency in the distribution of the down, it is preferable that it be done by an automatic layering process. The entire process may also be performed in a regulated air pressure chamber or a vacuum could be provided under the endless belt to retain the down feathers evenly distributed on the top surface 18 of the conveyor belt 14. The vacuum would retain the feathers in place from the feed end of the conveyor to the dryer station. Such an optional vacuum system is illustrated in FIG. 1 and identified by reference numeral 34.
Another modification is to feed the down feather sheet 10 from the output of the conveyor between a pair of fabric sheets which can then be sewn together whereby to sandwich the down feather sheet between fabric sheets to form quilts or fabric to be later pattern cut for the production of articles of apparel. It is also pointed out that in the process herein described the down feather sheet remains reasonably subtle to the feel rather than rigid and the thermal property of the down is substantially preserved. The sheets also produced may be fragile or delicate and it is not essential that these be strong like a blanket. They merely need to be capable of packaging and onward shipment to some other facilities to accommodate further processing.
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A method of fabricating a down feather sheet is described and it comprises forming a sheet of down feathers having been treated whereby to retain a homogeneous form. A binder is associated with the down feathers whereby they are retained together in sheet form. The down feather sheet product is also described.
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[0001] This invention relates generally to the art of packaging films, in particular to films useful in the packaging of food and other products, especially perishable food products, and to a method of making such films.
BACKGROUND
[0002] Packaging films, and especially films of polyolefin materials, have been used in the past to package various articles including perishable food-products that require protection from the environment.
[0003] Bags made from heat shrinkable polymeric films have wide acceptance for poultry, fish, red meats and processed meats packaging. One of the benefits of using heat-shrinkable packaging is the ability to provide an intimate contact between the product and the film packaging to prevent ice build up between the product and the film packaging during freezing. This intimate contact prevents problems such as freezer burn and moisture loss. At the same time as premium perishable food products are produced, many processors also produce frozen products which often require a separate packaging line. Many frozen perishable foods are either over-wrapped or bagged without vacuum packaging where they are classified as commodity food products. In the past this has not been easy to do because traditionally a different film is used for wrapping chilled cuts as opposed to those cuts which are selected to be frozen. This has meant that two packaging lines are needed, with one line dedicated to cuts which will be subsequently frozen and one line dedicated to cuts that are to remain chilled.
[0004] With the increased focus on food safety and product traceability processors desire to put commodity products through the same processing lines as non-commodity (premium) products. In order to do this it is necessary to develop a low cost, hot water shrinkable material that will have the required thermal resistance to the heat sealing and shrinking processes used for non-commodity products.
[0005] It is an object of the invention to provide a packaging film that overcomes some of these known difficulties, or which at least provides the public with a useful alternative.
STATEMENT OF INVENTION
[0006] In a first aspect the present invention provides a non-oxygen barrier packaging film including:
[0007] (a) an outer layer comprising an ionomer to provide thermal resistance and
[0008] (b) an inner layer comprising a polymeric material having a sealing temperature lower than the sealing temperature of said outer layer.
[0009] Preferably, the packaging film may further include a core layer.
[0010] Preferably, said inner layer and said core layer may further include a tinting material.
[0011] Preferably, the packaging film is transparent.
[0012] Preferably, said inner layer or said core layer comprises a polymeric material selected from the group consisting of: ethylene vinyl acetate, linear low density polyethylene, low density polyethylene, very low density polyethylene, or metallocene catalysed polyethylenes and blends thereof.
[0013] Preferably, the packaging film has a gauge of between 19-120 microns.
[0014] More preferably the packaging film has a gauge of between 40-80 microns.
[0015] Most preferably, each layer of the packaging film has gauge of between 9-60 microns.
[0016] Preferably the packaging film is oriented.
[0017] More preferably the packaging film is biaxially oriented.
[0018] Preferably said tinting material is selected from a range of known dyes or pigments that are food approved additives.
[0019] In a second aspect of the present invention there is provided a method of making a non-oxygen barrier packaging film which includes the steps of
[0020] (a) co-extruding a first layer comprising an ionomer and a second layer comprising a polymeric material having a sealing temperature lower than said first layer; and
[0021] (b) cooling the co-extruded film.
[0022] Preferably, the method includes the further step of heating the co-extruded film to its orientation temperature range and stretching and orienting the heated film.
[0023] Preferably, the co-extrusion step is a tubular co-extrusion step.
[0024] Most preferably, the film produced in the tubular co-extrusion step is biaxially oriented and stretched by a trapped bubble technique.
[0025] Preferably the film produced in the tubular co-extrusion step has said first layer is the outer layer and said second layer is the inner layer.
[0026] In a further aspect of the present invention there is provided a method of packaging a food product, including the steps of
[0027] (a) taking a heat shrinkable film as described above;
[0028] (b) wrapping a food product in said film such that said first layer is the outer layer and said second layer is the inner layer;
[0029] (c) heat sealing together the edges of said film about said food product; after vacuum packaging; and
[0030] (d) heat shrinking said film about said food product.
[0031] Preferably, the film is a co-extruded tubular film and step (b) involves cutting a length of said tube and locating said food product within the tube. Preferably, the film is a co-extruded tubular film and step (c) involves heat sealing each end of said tube.
[0032] Preferably, one end of the tubular film is heat sealed prior to locating the food product in the tube.
[0033] Preferably, said heat shrinking is achieved by a hot air stream or a hot water bath.
[0034] Preferably, the method further includes the step of printing onto the outer layer of said film.
[0035] The term “sealing temperature” as used in this specification is intended to refer to the temperature at which the layers of the packaging film are welded or sealed together, when passed through, for example a thermal impulse sealer. The outer layer will resist the thermal impulse more than the inner layer with the inner layer becoming more tacky than the outer layer and enabling a weld or seal to be formed.
[0036] The term “ionomers” as used in this specification includes ionomers that are derived from acid copolymers by wholly or partially neutralizing the acid moiety of the acid copolymer with a cation, such as sodium or zinc. Acid copolymers are well known and generally comprise an olefin monomer (such as ethylene) which is copolymerized with an acid comonomer (such as acrylic acid or methacrylic acid).
[0037] The term “oriented” is used to define a polymeric material that has been heated and stretched to realign the molecular configuration, the stretching being accomplished typically by a trapped bubble process. Such a process is well-known in the art. A thermoplastic material stretched in one direction only is uniaxially oriented and a material stretched in a longitudinal as well as the transverse direction is biaxially oriented.
[0038] Further aspects of the invention will become apparent with reference to the following description and accompanying examples thereof.
DETAILED DESCRIPTION
[0039] The films of the invention may be produced by a conventional tubular coextrusion technique. In this technique a hot melt of resins is extruded through an annular circular die. The tube that is formed is cooled and flattened. The resulting tape is then fed through a hot water bath, at a temperature of from about 80-98° C. This heating step is done just prior to orienting the film. The orientation temperature ranges are well known for many polymeric materials and are generally below the melting point of the film. Preferably films according to the invention are heated from about 80 to 98° C. On leaving the bath the tube is then inflated and blown to give a wall thickness in the blown tube of about 19-120 microns. This “trapped bubble” technique is known in the art. The tube is then drawn away from the nip rollers that trap the air bubble. The rate of draw is controlled to provide the longitudinal stretch. The film is then rapidly cooled to set the orientation and rolled up to give the desired biaxially oriented bi-layer film. By this technique, shrinkability is imparted to the film by the orientation of the film during its manufacture. This allows the film to shrink or, if restrained, to create shrink tension within the packaging film on exposure to heat, for example, in a hot water bath or by exposure to hot air. In a typical process, the degree of stretch in both the longitudinal and transverse directions can be varied to impart the desired degree of shrinkability to the film upon subsequent heating.
[0040] Premade bags or bags made from rollstock at point of use from such heat shrinkable film are supplied to a meat packer being sealed at one end to receive a meat product. After the cut of meat is placed in the bag, the bag will be closed as part of a vacuum packaging process. Afterwards each food product is heat shrunk by applying heat, for example, by immersing the filled bag in a hot water bath or by conveying it through a hot air or hot water tunnel.
[0041] The product typically has a free shrink in the transverse direction of 35-75% and in the machine (longitudinal) direction of 25-65% over the temperature range 70-98° C.
[0042] The product is typically sealed at a temperature of 110-160° C. The product is also preferably internally dusted (for example with starch) to prevent blocking during manufacture.
EXAMPLE 1
[0043] A packaging film was produced in accordance with the process described above. The outer layer was extruded from the Du Pont Surlyn™ 1601B2 resin, which has a density of 0.93 g/cm 3 at a temperature of 165-185° C. The melt flow index of Surlyn™ is 0.13 g/10 min.
[0044] The inner layer was extruded from, Exxon Escorene™ EVA at a temperature of 145-150° C. The EVA resin comprises 9% by weight of vinyl acetate and has a density of 0.93 gm/cm 3 . The melt flow index of the EVA is 2.0 gms/10 min. The sealing temperature of the EVA is 110-160° C.
[0045] The gauge of the outer layer was between 20-30 microns and the gauge of the inner layer was 25-35 microns.
[0046] The film produced in Example 1 was a shrinkable film that provided a tight, smooth appearance to a product wrapped in the film. The film has an added toughness providing good abuse resistance. The film also had good optical properties after shrinking.
EXAMPLE 2
[0047] A packaging film was produced in accordance with the process described above. The outer layer was extruded from the DuPont Surlyn 1601B2 resin, which has a density of 0.93 g/cm3 at a temperature of 165-185 C. The melt flow index of Surlyn is 0.13 g/10 min.
[0048] The inner layer was extruded from Exxon Escorene EVA at a temperature of 145-150 C. The EVA resin comprises 9% by weight of vinyl acetate and has a density of 0.93 g/cm3. The melt flow index of EVA is 2.0 g/10 min. The sealing temperature of the EVA is 110-160 C.
[0049] A blue masterbatch tint was added to the inner layer at a loading of 5 g/10 kg of EVA.
[0050] The gauge of the outer layer was between 20-30 microns and the gauge of the inner layer was 25-35 microns.
EXAMPLE 3
[0051] A packaging film was produced in accordance with the process described above. The outer layer was extruded from the DuPont Surlyn 1601B2 resin, which has a density of 0.93 g/cm3 at a temperature of 165-185 C. The melt flow index of Surlyn is 0.13 g/10 min.
[0052] The inner layer was extruded from Exxon Escorene EVA at a temperature of 145-150 C. The EVA resin comprises 9% by weight of vinyl acetate and has a density of 0.93 g/cm3. The melt flow index of EVA is 2.0 g/10 min. The sealing temperature of the EVA is 110-160 C.
[0053] The gauge of the outer layer was between 35-55 microns and the gauge of the inner layer was 35-55 microns.
EXAMPLE 4
[0054] A packaging film was produced in accordance with the process described above. The outer layer was extruded from the DuPont Surlyn 1601B2 resin, which has a density of 0.93 g/cm3 at a temperature of 165-185 C. The melt flow index of Surlyn is 0.13 g/10 min.
[0055] The inner layer was extruded from Exxon Escorene EVA at a temperature of 145-150 C. The EVA resin comprises 10% by weight of vinyl acetate and has a density of 0.93 g/cm3. The melt flow index of the EVA is 0.35 g/10 min. The sealing temperature of the EVA is 110-160 C.
[0056] The gauge of the outer layer was between 35-40 microns and the gauge of the inner layer was 30-40 microns.
[0057] Oriented multi-layer films in accordance with the invention have good abuse resistance, good optical properties, especially after shrinking, and good sealability making them especially suitable for packaging food, especially frozen red and white meat products.
[0058] An advantage of the films produced by this method is that they are lower cost to produce than oxygen barrier shrink bags which can also be used for packaging frozen meat products. The films also have excellent strength and puncture resistance properties. The films have an excellent colour and clarity and heat sealing properties.
[0059] Another advantage of the films of the present invention is that the first layer tends to have a natural tendency to shrink very slightly at room temperature relative to the second layer. This tendency means that the ends or cut edges of the film tend to curl slightly making it easier to locate the edge or end of the film. This also assists when one is wrapping or locating a food product in a tube of film.
[0060] Where in the foregoing description reference has been made to integers having known equivalents, then those equivalents are herein incorporated as if individually set forth.
[0061] Although the invention has been described with reference to specific embodiments, it is to be appreciated that variations and modifications may be made without departing from the spirit and scope of the invention.
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The present invention provides a packaging film including: (a) an outer layer comprising an ionomer to provide thermal resistance; and (b) an inner layer comprising a polymeric material having a sealing temperature lower than the sealing temperature of the outer layer. The invention also provides a method of making a paCkaging film as described above, which includes the steps of (a) co-extruding a first layer comprising an ionomer and a second layer comprising a polymeric material having a sealing temperature lower than the first layer; and (b) cooling the co-extruded film. A method of packaging a food product is also provided.
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CROSS REFERENCE TO RELATED APPLICATIONS
This Application is related to application Ser. No. 07/625,574 filed on even date herewith entitled "A Method of Forming High-Temperature Resistant Polymers" (McArdle et al).
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to difunctional styryloxy compounds which are cationically polymerizable, and to polymers thereof, particularly for use in surface coatings, films, inks, adhesives, sealants and the like.
2. Description of the Related Art
U.S. Pat. No. 4,543,397 Woods et. al., describes polyfunctional cationically polymerizable styryloxy compounds of the formula I or II ##STR3## where R 1 and R 2 are H, or one of R 1 and R 2 is H and the other is methyl; R 3 and R 4 are H, lower alkyl or alkoxy if R 2 is not methyl; R 5 is a divalent hydrocarbon radical; G is a multivalent organic or inorganic radical free of amine, aliphatic hydroxyl, aliphatic thiol or other groups which interfere with cationic polymerization; and n is an integer of two or more.
Polyfunctional telechelic styryloxy monomers of the kind described in U.S. Pat. No. 4,543,397 are generally of high molecular weight. Even so, example 10 of that Patent describes the preparation of 4-allyloxystyrene of the formula III ##STR4##
This compound is cationically active but it forms linear polymers which are purple/blue in color and only 10% insoluble in organic solvents i.e. little if any crosslinking has occurred.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide simple low viscosity liquid styryloxy monomers which can be crosslinked and which form transparent polymers.
The invention provides styryloxy compounds of the formula IV ##STR5## wherein R 1 and R 2 are H, or one of R 1 and R 2 is H and the other is methyl; R 7 and R 8 (which may be the same or different) are H, C 1 -C 5 alkyl or C 1 -C 5 alkenyl; or one of R 7 and R 8 may be --OR 6 or C 1 -C 5 alkoxy or C 1 -C 5 alkenyloxy if R 2 is not methyl;
R 6 is selected from the group consisting of: ##STR6## where R 10 is C 1 -C 5 alkyl; and R 11 , R 12 and R 13 , which may be the same or different, are H or C 1 -C 5 alkyl.
Preferably at least one of R 11 , R 12 and R 13 is C 1 -C 5 alkyl.
In one preferred embodiment, R 11 is H and R 12 and R 13 are both C 1 -C 5 alkyl. In another preferred embodiment, R 11 and R 12 are H, and R 13 is C 1 -C 5 alkyl.
A preferred group of compounds within the scope of the present invention are those wherein the styryl moiety (R 2 CH═C(R 1 )--) is para to the --OR 6 moiety. In such compounds, it is also further preferred that at least one position ortho to the --OR 6 moiety is unsubstituted, i e., H. Especially preferred compounds are those wherein R 1 , R 2 , R 7 and R 8 are H.
The most preferred compounds are of the formula V ##STR7## wherein R 9 is selected from the group consisting of: ##STR8##
The compounds of the present invention are monofunctional with respect to the styryl group but are difunctional because of the other cationically active substituent --OR 6 . They are compatible with photoinitiators, which are soluble therein, and they can be photocured to give highly transparent polymeric films with good mechanical properties after short irradiation times e.g. 10 seconds or less. Thus, low viscosity monomers may be converted to strong crosslinked polymers.
In one aspect therefore, the present invention provides a polymerizable composition comprising a styryloxy compound of formula IV together with a photoinitiator.
The compounds of the present invention may also be used as reactive diluents e.g. in epoxy resins, vinyl ether resins, styryloxy resins, etc. As reactive diluents, these compounds may co-react with the other constituent(s) or they may react concurrently with the polymerization of the co-constituent(s).
The compounds of the present invention are especially useful as co-constituents in combination with other styryloxy monomers. Additionally, they have a particularly surprising effect in admixture with 4-allyloxystyrene (formula III) in that the addition of even small percentages of one of the compounds of formula IV to 4-allyloxystyrene produces a monomer mixture which polymerizes to a transparent insoluble film.
The present invention therefore also provides a polymerizable composition comprising 4-allyloxystyrene of formula III in admixture with a styryloxy compound of formula IV as defined herein, together with a photoinitiator. In general, the styryloxy compound of formula IV is present in an amount of at least 1% by weight, preferably in the range of from about 2.5% to about 35% by weight, most preferably in the range of from about 3% to about 10% by weight based on the combined weight of the allyloxystyrene and the styryloxy compound of formula IV.
It has also surprisingly been found that a synergistic effect is achieved by combining an admixture of 4-allyloxystyrene and a styryloxy compound of formula IV with a vinyl ether monomer, specifically a divinyl ether of a polyalkylene oxide e.g. the divinyl ether of triethylene oxide.
In a further aspect therefore the present invention provides a photopolymerizable composition comprising:
(A) a styryloxy component selected from the group consisting of:
(i) 4-allyloxystyrene,
(ii) at least one styryloxy compound of formula IV as defined above, and
(iii) a mixture of (i) and (ii),
(B) a divinyl ether of a polyalkylene oxide and
(C) a photoinitiator, the ratio of (A):(B) being in the range from 1:9 to 20:1.
Preferably the ratio of (A) to (B) is in the range 2:1 to 9.1, more preferably 1:1 to 4:1, most preferably about 3:1.
It is especially preferred that the styryloxy component (A) be a mixture (iii) of the allyloxy styrene (i) and styryloxy compound of formula IV (ii). Within said mixture, the ratio of (i) to (ii) is preferably in the range 20:1 to 1:2, more particularly 7.5:1 to 2:1, especially about 6:1 to 3:1. These ratios are calculated without reference to any small amounts of other components.
The divinyl ether of a polyalkylene oxide preferably is of the formula CH 2 ═CH--O--(CH 2 ) n --O] m CH═CH 2 , wherein n=1-6 (preferably n=2 ) and m is greater than or equal to 2 (preferably m=2-10). The preferred compound is the divinyl ether of triethylene oxide, which is commercially available.
Although any of the individual compounds above as well as combinations of A(i) or A(ii) with (B) provide cured compositions with excellent properties, the synergistic combination A(iii) and mixtures thereof with B have been found to manifest superior properties, particularly as regards bond strength.
The photoinitiator may be any suitable UV cationic initiator. Such UV cationic photoinitiators include salts of a complex halogenide having the formula:
[A].sub.b.sup.+ [MX.sub.e ].sup.-(e-f)
where A is a cation selected from the group consisting of iodonium, sulfonium, pyrylium, thiopyrylium and diazonium cations, M is a metalloid, and X is a halogen radical, b equals e minus f, f equals the valence of M and is an integer equal to from 2 to 7 inclusive, e is greater than f and is an integer having a value up to 8. Examples include di-p-tolyl iodonium hexafluorophosphate, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroarsenate and UVE (or GE) 1014 (trademark of General Electric), a commercially available sulfonium salt of a complex halogenide.
The precise mechanism or mechanisms by which the compounds of the present invention homopolymerize and/or copolymerize, as appropriate, to form a substantially insoluble crosslinked polymer is not known. Although not intending to be bound by any particular theory, it is believed that occurs through the unsaturation in the oxy (--OR 6 or --OR 9 ) moiety. Specifically, it is believed that the oxy mo may crosslink between pendant oxy moieties of other styryloxy monomers or between pendant oxy moiety and free styryl moiety (R 2 CH═C(R 1 )--) as well. In compositions comprising other co-constituents, e.g., 4-allyloxystyrene and/or divinyl ether, the crosslinking will also occur by a co-reaction between the styryl or oxy moieties of the styryloxy compounds of formula IV with co-reactive sites on the co-constituent.
Furthermore, although it is believed that there may be some minor degree of a photoinduced claisen-type rearrangement in the styryloxy compounds of formula IV, it is not believed that the resultant monomers participate to a large extent, if at all, in the concurrent photo induced crosslinking reaction. This claisen-type rearrangement does, however, play an important role in a subsequent heat treatment step as described in the aforementioned co-filed patent application of McArdle et al.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention may be illustrated by reference to the following non-limiting examples, in which all percentages are by weight unless otherwise indicated.
4-Isobutenyloxystyrene
4-Ethyl acetoxy benzaldehyde was prepared by the reaction of one mole of ethyl bromoacetate with one mole of 4-hydroxy benzaldehyde in the presence of one mole of anhydrous Potassium Carbonate in refluxing acetone. This precursor material was vacuum distilled after filtration and concentration of the reaction mixture. The precursor boiled in the range 138°-140° C. at 0.2 mbar and appeared as a slightly yellowish liquid which crystallized on standing.
4-Isobutenyloxystyrene was prepared from 4-ethyl acetoxy benzaldehyde by Wittig reduction. Thus to Methyl triphenyl phosphonium bromide (205.6 g, 0.576 mole) in anhydrous tetrahydrofuran and under a nitrogen atmosphere, was added Sodium Amide (26 g, 0.576 mole plus excess to account for its 90% strength). The mixture was stirred at room temperature and became slightly yellow after 30 minutes. After 31/2 hours of stirring the mixture was deep yellow and 4-ethylacetoxy benzaldehyde (60 g, 0.288 mole) was added portionwise. When the addition was complete, the mixture had turned a deep tan color. The mixture was further refluxed for 2-3 hours. On cooling and filtering, the reaction mixture was concentrated and continuously extracted with 40°-60° C. bp petroleum ether in which reaction by-product triphenylphosphine oxide is sparingly soluble, whereas the desired product has high solubility. On concentration of the extracts a yellow-brown oil resulted, 10 g of which subjected to vacuum distillation. Three fractions resulted which has the following characteristics:
Fraction (1): bp˜150° C. @0.3 mbar; IR (Key bands) split C═O stretch (1760, 1735 cm -1 , weak), olefinic=C--H stretch (1660 cm -1 weak), conjugated olefinic=C--H (1625 cm -1 medium).
Fraction (2): bp˜170° C. @0.3 mbar; IR (Key bands) as for (1) with more intense C═O bands and an ill defined ester pattern --C(O)--O-- (1220-1240 cm -1 ).
Fraction (3): bp˜195° C. @0.3 mbar; IR (Key bands), --CH stretch [2995 (asym.), 2800 (sym) cm -1 ], split C═O (1760, 1735 cm.sup. -1 intense), conjugated olefin (only) (1625 cm -1 , med.), characteristic (1205-1240 cm -1 , intense). The ratio for Fraction 1:2:3 was 11:3:1.
Fraction 1 was further purified by spinning plate preparative thin layer chromatography with 40°-60° C. bp petroleum ether as eluant. Six grammes of a water clear low viscosity liquid with a characteristic aniseed smell were thus isolated which was 100% pure by HPLC. GC-MS evidence confirmed a molecular weight of 174; the major abundances from the fragmentation pattern were 159, 120, 91, 77, 65, 55 and 39 m/g z . High field H' N.M.R. (CDCl 3 ; TMS) assignments were as follows:
______________________________________ ##STR9##
______________________________________ 2H d 7.33 ppm H.sub.5, 5.sup.1, 6, 6.sup.1, J.sub.5,6 = 8.5 H.sub.z2H d 6.90 ppm1H dd 6.65 ppm H.sub.7, J.sub.7,8 = 17 H.sub.z ; J.sub.7,9 = 17 H.sub.z1H dd 5.60 ppm H.sub.9, J.sub.9,7 = 17 H.sub.z ; J.sub.9,8 = 1 H.sub.z1H dd 5.10 ppm H.sub.82H Septet 4.95 ppm H.sub.2,12H S 4.36 ppm H.sub.4,33H S 1.78 ppm Me.sub.1______________________________________
The cationically active monomer 4-isobutenyloxystyrene when formulated with the commercially available cationic photoinitiators known as UVE (or GE) 1014 or alternatively Degacure(®) K126 (the former being products of General Electric Company whilst the latter is a Degussa material) at levels typically of 15 μl initiator per gramme of monomer, gave compatible clear compositions of low viscosity which photocured in 5 seconds at 100 mW/cm 2 exposure at predominantly 366 nm to give tack free clear and colorless films with high gloss and flexibility. These films showed a minimum of 75% insolubility after room temperature photocure in repeated solvent extractions over 24 hours with solvents such as toluene, CH 2 Cl 2 and DMSO.
Photocured films (at room temperature) had a glass transition temperature (Tg) at 55° C. with a maximum Tan δ amplitude of 0.42 and a dynamic modulus E'≧562 MPa at temperatures of 50° C. to -100° C., the last data being measured by Dynamic Mechanical Thermal Analysis (DMTA) at a frequency of 1 Hz. Photocured films at elevated temperature (50° C.) show Tg at 67° C. with similar modulus performance.
An alternative procedure for the direct introduction of isobutenyl groups into phenols employs methylallyl chloride as a reagent (cf. Bartz, Miller and Adams, J. Am Chem Soc. 57, 371, 1935). Thus the Wittig reduction and isobutenyl formation may be separated into two steps by using 4-isobutenyloxy benzaldehyde as a substrate in place of 4-ethyl acetoxy benzaldehyde.
2-Methylpropenyloxystyrene
A saturated methanolic KOH solution was prepared, 15 g. of which was charged into a round bottom flask. To the saturated solution was added approximately 5 g of 4-isobutenyloxystyrene (Example 1) and the mixture was heated and stirred for 6 hours at 110° C., during this time the upper liquid layer turned from yellow to pink. On cooling, the upper liquid layer was easily drawn off from the solid bottom layer and the former was vacuum distilled, boiling in the range 52°-60° C. at 0.1 mbar. The distillate was a water clear low viscosity liquid with a characteristic aniseed smell. IR analysis indicated the presence of an intense 1670 cm -1 band characteristic of β-substituted vinyl ethers and not present in the parent monomer (Example 1) and also the 960 cm 1 band due to, CH wag in substituted vinyl ethers. High resolution H' NMR (CDCl 3 ; TMS) gave the following assignments:
______________________________________ ##STR10##
______________________________________ 2H d 7.33 ppm H.sub.2,2.spsb.1.sub.,3,3.spsb.1, J.sub.2,3 = 8.5 H.sub.z2H d 6.90 ppm1H dd 6.65 ppm H.sub.4, J.sub.4,5 = 11 H.sub.z J.sub.4,6 = 17 H.sub.z1H septet 6.20 ppm H.sub.1, J.sub.1, Me = 1 H.sub.z1H dd 5.60 ppm H.sub.6, J.sub.4,6 = 17 H.sub.z J.sub.5,6 = 1 H.sub.z1H dd 5.10 ppm H.sub.56H 2Xd 1.70 ppm; Me J.sub.1, Me = 1 H.sub.z______________________________________
This monomer was cationically active as before, curing tack free i 10 seconds @100 mW/cm 2 @predominantly 366 nm. The resulting polymer was a flexible solid with a Tg of 85° C. (1 Hz by DMTA).
EXAMPLE 3
4-Allyloxystyrene
4-allyloxybenzaldehyde was prepared by reaction of allyl bromide on 4-hydroxybenzaldehyde in refluxing acetone in the presence of K 2 CO 3 . The distilled product was used as a precursor for 4-allyloxystyrene synthesis.
To approximately one liter of anhydrous THF and under a N 2 atmosphere was added 265 g (0.74 mole) of methyl triphenyl phosphonium bromide in a multinecked flask equipped with an efficient mechanical stirrer. Sodium amide 93-97%, (approximately 0.74 mole) was added and stirring at room temperature continued for about three hours until a deep canary yellow color had formed. 4-allyloxybenzaldehyde (100 g, 0.62 mole) was then added gradually and the reaction mixture, now tan in color, was subsequently brought to reflux and maintained there for about four hours. The reaction was stopped when TLC analysis showed the aldehyde to be consumed. On cooling the filtrate was extracted with 40°-60° C. bp petroleum ether until HPLC analysis showed that less than 40% of the contents was by-product triphenyl phosphine oxide. The concentrated extracts at that stage were subjected to vacuum distillation yielding a water clear liquid of low viscosity, bp≅50° C. at 0.6 mbar, with a characteristic aniseed smell.
Analysis by GC-MS indicated the liquid to contain two components, a lower boiling component present at 3% and a higher boiling component at 97%. Both were isomeric materials of 160 mass units by MS analysis. The major component was identified as 4-allyloxystyrene by 1 H 270 MHz NMR analysis, IR analysis and GC-MS analysis following separation of a sample of the distillate by preparative TLC. The minor component was identified, by the same techniques and from the same isolation procedure, as 4-propenyloxystyrene (see Example 4).
EXAMPLE 4
4-Propenyloxystyrene
This material was prepared by base catalyzed isomerization of 4-allyloxystyrene using saturated methanolic KOH in the same way as described in Example 2 (6 hours, 150° C). IR analysis indicated intense 1670 cm -1 absorption due to β-substituted vinyl ether with concomitant disappearance of the 1640 cm -1 allyl olefinic signal present in the precursor, again a strong 960 cm -1 absorbance was noted in the new molecule. The pure material was prepared by vacuum distillation boiling at 48° C. at 0.3 mbar (cf. 60° C. @0.3 mbar for 4-alloxystyrene). GC-MS analysis confirmed a molecular weight of 160 with major m/z peaks at 120, 91, 77, 65, 39. High resolution 'H NMR (CDCl 3 ; TMS) gave the following assignments:
______________________________________ ##STR11##
______________________________________2H d 7.37 ppm H.sub.2,2.spsb.1, J.sub.1,2 = 8.5 H.sub.z2H d 6.95 ppm H.sub.1, 1.sup.11H dd 6.65 ppm H.sub.5, J.sub.5,6 = 11.0 H.sub.z J.sub.5,7 = 18.0 H.sub.z1H dq 6.40 ppm H.sub.3, J.sub.3,4 = 6.0 H.sub.z J.sub.B,Me = 1.5 H.sub.z1H dd 5.60 ppm H.sub.7, J.sub.6,7 = 1.0 H.sub.z J.sub.5,7 = 18 H.sub.z1H dd 5.15 ppm H.sub.6, J.sub.5,6 = 11 H.sub.z J.sub.6,7 = 1.0 H.sub.z1H dq 5.40 ppm H.sub.4, J.sub. 3,4 = 6.0 H.sub.z J.sub.4,Me = 8.0 H.sub.z3H dd 1.70 ppm Me.______________________________________
An alternative method of synthesis involves reaction of 1-bromo-1-propene with 4-hydroxybenzaldhyde in basic conditions followed by Wittig reduction of the reaction product.
The monomer was cationically active, photocuring tack free in about 5 seconds at room temperature when formulated with the photoinitiators mentioned in Example 1. The monomer is compatible with the said photoinitiators giving clear solutions with characteristic aniseed like smell.
EXAMPLE 5
Compositions which photocure cationically to give tack free insoluble films were prepared, starting with the mixture produced in Example 3 i.e. 97% 4-allyloxystyrene and 3% 4-propenyloxystyrene, and increasing the proportion of the propenyl compound up to 100% propenyl compound. The photoinitiator(s) from Example 1 were also present at about 1% level. The presence of the propenyloxystyrene transforms the properties of cationically active allyloxystyrene in that even at 3% level of 4-propenyloxystyrene crosslinking occurs and colorless largely insoluble films result. Without propenyloxystyrene, highly colored soluble linear polymers from cationically active allyloxystyrene result. Thus polymer films photocured from monomer mixtures such as 97% 4-allyloxystyrene and 3% 4-propenyloxystyrene or 91% 4-allyloxystyrene and 9% 4-propenyloxystyrene gave 90% insoluble residues in duplicated solvent extraction tests. Photocured films submitted to DMTA as in Example 1 had glass transition temperatures as follows:
______________________________________% 4-propenyloxystyrene Tg______________________________________0 62° C.3 75° C.9 87° C.______________________________________
The dynamic modulus E' for the crosslinked copolymers was 200 MPa to 60° C. from at least 10° C.; all DMTA data being quoted at 1 Hz.
As described above, the crosslinking resulting from the photopolymerization of the allyloxystyrene and propenyloxystyrene is believed to be largely due to the cationically active propenyloxy moiety of the 4-propenyloxystyrene. Generally, the styrenic portions of the two components will polymerize to form polystyrene-type chains having the respective allyloxy and propenyloxy moieties pendant thereto. The propenyloxy moiety will cationically crosslink with other propenyloxy moieties, as well as other pre-(non-reacted) styrenic (CH 2 ═CH--) moieties from either monomers. Although less active, it is also possible that the propenyloxy moiety may also crosslink with other pendant allyloxy moieties. In any event, as noted from the compositions of this Example 5, even low amounts of 4-propenyloxystyrene in the admixture results in a high degree of crosslinking as compared to 4-allyloxystyrene without the propenyloxystyrene.
EXAMPLE 6
A mixture of 4-allyloxystyrene and 4-propenyloxystyrene was prepared and analyzed by the GC-MS technique. The instrument used was a Hewlett-Packard 58-90 GC system with an electron impact mass selective detector. The column head pressure was 15 p.s.i. of Helium as carrier, column type was a 25 m capillary type of 0.25 mm with a BP10 coating. Injection was made at 300° C. from Analar (Trade Mark) grade chloromethane. Total ion current traces for the styryloxy mixture indicated three components to be present. Two components are isomeric and have molecular mass of 160 units. In order of ascending boiling points these two were identified as propenyloxystyrene and allyloxystyrene. The analysis also indicated the presence of a third compound referred to hereafter as K. The concentration of K in the gas chromatogram was dependent on the temperature of sample injection. Integration of GC data at 300° C. injection temperature characterized the styryloxy mixture as 22% propenyloxystyrene, 63% allyloxystyrene and 15% K. Proton NMR run at room temperature in CDCl 3 as solvent and TMS as reference indicated the styryloxy mixture to contain propenyloxystyrene and allyloxystyrene only.
Combinations of this styryloxy mixture with the divinyl ether of triethylene oxide known as DVE-3 commercially available from the GAF company, when formulated with the initiators described in Example 1, produced photocurable compositions which had superior properties to any of the individual components or to any mixtures outside of the optimized formulation range.
Pin-to-glass bond strengths for the respective compositions are summarized below (Table 1).
In Table 1, the following abbreviations are used:
DVE-3: Divinyl ether of triethylene oxide
H o : Composition containing 75% of the styryloxy mixture with 25% of DVE-3.
HI: Composition containing 50% of the styryloxy mixture with 50% of DVE-3.
HII: Composition containing 25% of the styryloxy mixture with 75% of DVE-3.
All percentages being by weight.
It will be seen from Table 1, that composition H o gives the best results of all those tested and that the combination of styryloxy type monomers with DVE-3 at the optimized range gives performance much better than either of the styryloxy monomers alone or the DVE-3 alone.
TABLE 1______________________________________Photocurable compositions containing 15 μl/gm GE1014 andexposed with 100 mW/cm.sup.2 at predominantly 366 nm. Pin-to-Glass Bond Strength (dN per sq. cm.) after exposure for:Compound/ 20 40 60Formulation Seconds Seconds Seconds Entry No.______________________________________Propenyloxystyrene 14 -- -- 1Allyloxystyrene 12 12 13 2DVE-3 76 66 72 3Propenyloxystyrene:DVE-3at 75:25 59 57 -- 4at 50:50 49 50 -- 5at 25:75 69 57 -- 6Allyloxystyrene:DVE-3at 75:25 87 84 80 7at 50:50 75 83 86 8at 25:75 72 79 90 9H.sub.o 125 125 127 10H.sub.I 95 103 87 11H.sub.II 85 82 103 12______________________________________
EXAMPLE 7
In Example 6 a synergistic improvement in bond strengths has been described for 75:25 styryloxy mixture: DVE-3 formulations containing photoinitiators. In the present example, the importance of the relative concentrations of various styryloxy isomers within the 75% styryloxy mixture content of the optimized formulation, is described.
In order to study the effect of varying the relative propenyloxystyrene and allyloxystyrene contents within the 75% styryloxy content photocurable compositions, a new batch of styryloxy monomers was prepared, characterized and modified. This batch of GC-MS analysis at 300° C. injection temperature indicated 22% propenyloxystyrene, 72% allyloxystyrene and 2% of K. The relative proportions of propenyloxystyrene and allyloxystyrene monomers were adjusted by addition of pure materials from separate stock so that nominally 50:50, 30:70, 20:80, 10:90 mixtures of propenyloxy to allyloxy monomers resulted, the K content never exceeded 2%. The said monomer mixtures then formed the 75% component of a mixture with DVE-3 (25%) together with photoinitiator. Pin-to-glass bond strengths were measured after photocuring with various exposure conditions. The results are summarized in Table 2 indicating that the optimum ratio of propenyloxy to allyloxy, is around 1:4.
TABLE 2______________________________________Photocurable compositions containing 15 μl/gm GE1014 andexposed with 100 mW/cm.sup.2 at predominantly 366 nm. Relative improvement (%) in Pin-to-glass bond strength for various mixtures (taking Entry 1 as standard) after exposure for: EntryFormulation: 20 Seconds 40 Seconds No.______________________________________37.5% propenyloxystyrene 100 100 137.5% allyloxystyrene 25% DVE-322.5% propenyloxystyrene 129 111 252.5% allyloxystyrene 25% DVE-3 15% propenyloxystyrene 153 154 3 60% allyloxystyrene 25% DVE-3 7.5% propenyloxystyrene 140 145 467.5% allyloxystyrene 25% DVE-3______________________________________
EXAMPLE 8
A further batch of styryloxy monomers was prepared and analyzed by the GC-MS technique at 300° C. injection temperature as 88% allyloxystyrene and 12% propenyloxystyrene only. The styryloxy monomer mixture was then formulated with DVE-3 in various proportions, together with photoinitiator pin-to-glass bond strengths were measured after photocuring for 20 seconds. The results are summarized in Table 3:
TABLE 3______________________________________Photocurable compositions containing 15 μl/gm GE1014 andexposed with 100 mW/cm.sup.2 at predominantly 366 nm.Formulation Styryloxy Pin-to-Glass Bond StrengthsDVE-3 Mixture (dN per sq. cm.)______________________________________90% 10% 6270% 30% 22*50% 50% 6925% 75% 115______________________________________ *Anomalous result
EXAMPLE 9
Another batch of styryloxy monomers was prepared and analyzed by the GC-MS Technique at 80% allyloxystyrene and 20% propenyloxystyrene only. A formulation consisting of 75% styryloxy monomer mixture, 25% DVE-3 and 15μl/gm -1 GE1014 was photocured for 20 seconds at 100 mW/cm 2 . Pin-to-glass bond strengths were measured and results in excess of 100 dN/sq. cm were obtained.
Certain of the photocured compositions produced as described above may be further crosslinked by treatment with heat to form high-temperature resistant polymers, as described in co-pending application Ser. No. 07/625,574 filed on even date herewith entitled "A Method of forming High-Temperature Resistant Polymers".
Obviously, other modifications and variations to the present invention are possible and may be apparent to those skilled in the art in light of the above teachings. Thus, it is to be understood that such modifications and variations to the specific embodiments set forth above are to be construed as being within the full intended scope of the present invention as defined by the appended claims.
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Styryloxy compounds of the formula IV ##STR1## wherein R 1 and R 2 are H, or one of R 1 and R 2 is H and the other is methyl;
R 7 and R 8 (which may be the same or different) are H, C 1 -C 5 alkyl or C 1 -C 5 alkenyl; or one of R 7 and R 8 may be --OR 6 or C 1 -C 5 alkoxy or C 1 -C 5 alkenyloxy if R 2 is not methyl;
R 6 is selected from the group consisting of: ##STR2## where R 10 is C 1 -C 5 alkyl; and R 11 , R 12 and R 13 , which may be the same or different, are H or C 1 -C 5 alkyl, are described as new low viscosity liquid styryloxy monomers which can be photocured and which form transparent polymers. They have an advantageous effect in a mixture with 4-allyloxystyrene, and this mixture has a synergistic effect in combination with divinyl ethers of a polyalkylene oxide.
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This is a divisional of application Ser. No. 08/664,442 filed Jun. 21, 1996.
This invention relates to composite framing members, more specifically to studs and tracks, joists and bands, headers, and rafters formed from wood and metal composites.
BACKGROUND AND PRIOR ART
Residential and light commercial construction generally use wood as the primary building material for studs, plates, joists, headers and trusses. However, all-wood construction has problems. The rapidly rising cost of raw wood supplies has in effect substantially raised the cost of these members. Further, the quality of available framing lumber continues to decline. Finally, wood is flammable and susceptible to insects and rot.
Due to these problems, many builders have been switching to using all steel framing. The costs between using wood or steel framing is getting closer. In January 1990, the cost of framing lumber was about $225 per thousand board feet, peaking to highs of $500 in both January, 1993 and January 1994. Since June 1995, the framing lumber composite price has been rising from $300 per thousand board feet. Estimates from the AISI and NAHB Research Center state at a framing lumber cost of $340 to $385, there would be no difference between the cost of framing a house in steel as compared in wood. Thus, the break-even point between wood and steel framing is at about $360 per thousand board feet of framing lumber, and the lumber price has exceeded that point several times in recent years by as much as 40%, giving steel a competitive advantage.
Recycling has additionally helped the cost of steel to remain on a stable or downward trend. Steel costs have varied little in recent years. Traditionally variations can be correlated to steel demand by the automobile industry when demand is high, steel usually increases slightly in price. Consequently, the use of metal framing in residential and light commercial construction is increasing, a trend recognized and encouraged by the American Iron and Steel Institute (AISI).
All steel studs, tracks and trusses are being manufactured by Tri-Chord, HL Stud Corporation, Truswall Systems, Techbuilt Manufacturing, Knudson Manufacturing, John McDonald, and MiTek Ultra-Span Systems.
A problem with using all steel framing is its high thermal conductivity, leading to thermal bridging, "ghosting", and greater potential for water vapor condensation on interior wall surfaces. "Ghosting" is when an unsightly streak of dust accumulates on the interior wallboard, where the steel studs lie behind, due to an acceleration of dust particles toward the colder surface. Another problem of using all steel framing is the increased energy use for space conditioning (heating and cooling). Metal used for exterior framing members allows greater conduction heat transfer between the outside and inside surfaces of a wall, roof or floor. In colder climates, this increased conduction can cause condensation in interior surfaces, contributing to material degradation and mold and mildew growth. Metal framing also decreases the effectiveness of insulation installed in the cavity between the metal framing due to increased three dimensional thermal shorting effects. Higher sound transmission is another disadvantage of metal framing since sound conductivity is greater in metal than in wood. Electricians have more difficulty working with all steel framing when running holes for wiring since metal is more difficult to drill than wood, and grommets or conduits must be used to protect the wire.
U.S. Pat. No. 5,285,615 to Gilmour describes a thermal metallic building stud. However, the Gilmour member is entirely formed from metal. In Gilmour, the thermal conductivity is only partially reduced by having raised dimples on the ends contacting other building materials.
U.S. Pat. No. 3,960,637 to Ostrow describes impractical wood and metal composites. Ostrow requires each end flange have tapered channels, the end flanges being formed from extruded aluminum, molded plastic and fiberglass. Ends of the vertical wood web must be fit and pressed into a tapered channel. Besides the difficulty of aligning these parts together, other inherent problems exist. Extruding the channel flanges from aluminum or using molds, cuts and rolling to create the channelled plastic and fiberglass end flanges is expensive to manufacture. To stabilize the structures, Ostrow describes additional labor and manufacturing costs of gluing members together and sandwiching mounting blocks on the outsides of each channel.
Other metal and wood framing member patents of related but less significant interest include: U.S. Pat. No. 5,452,556 to Taylor; U.S. Pat. No. 5,440,848 to Deffet; U.S. Pat. No. 5,072,547 to DiFazio; U.S. Pat. No. 4,875,316 to Johnston; U.S. Pat. No. 4,301,635 to Neufeld; U.S. Pat. No. 4,274,241 to Lindal; U.S. Pat. No. 4,031,686 to Sanford; and U.S. Paat. No. 3,531,901 to Meechan.
SUMMARY OF THE INVENTION
The first objective of the present invention is to provide a metal/wood composite wall stud that increases the total thermal resistance of a typical steel framed insulated wall section by some 43 percent and would eliminate interior condensation and "ghosting" for all but the coldest regions of the United States.
The second object of this invention is to provide a wood and metal composite framing combinations that achieve a resource efficient and economic construction framing member. Metal is used for its high strength, and potentially lower cost and resource efficiency through recycling. Wood is used primarily for its lower thermal conductivity and for its availability as a renewable resource, and for its workability.
The third object of this invention is to provide a wood and metal composite framing members that allows electricians to be able to route wires through walls in the same way they are accustomed to doing with solid framing lumber.
The fourth object of this invention is to provide a wood and metal composite framing member that would be easy to manufacture.
The fifth object of this invention is to provide a wood and metal composite framing member that has low sound conductivity compared to prior art steel framing members.
The sixth object of this invention is to provide a wood and metal composite framing member that has reduced effects from flammability compared to all wood members.
The invention includes J-shaped, L-shaped, triangular shaped cross-sectional metal forms (Plate legs) connected by a wood midsections, whereby the wood is fastened to the metal by machine pressing of the metal to wood, similar to the common truss plate, or by nails, staples, screws, or other mechanical fastening means, or by adhesive glue. The outward faces of the metal members are pre-formed with four longitudinal ridges such that the contact surface area to applied sheathings is reduced by about 90%.
Metal and wood composites are used to create framing members (studs and tracks, joists and bands, headers, rafters, and the like) for light-weight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break. The metal used can be steel of approximately 18 to approximately 22 gauge.
Metal/wood composite framing members can be used in place of conventional wood framing members such as: 2×4 and 2×6 wall studs, and 2×8, 2×10, 2×12 and other dimensions of roof rafters, floor joists and headers. The novel framing members can be used to replace conventional light-gauge steel framing to reduce thermal transmittance and sound transmission.
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1A is a perspective isometric view of a first preferred embodiment metal/wood stud.
FIG. 1B is a cross-sectional view of the embodiment of FIG. 1A along arrow AA.
FIG. 2A is a perspective isometric view of a second preferred embodiment metal/wood stud.
FIG. 2B is a cross-sectional view of the embodiment of FIG. 2A along arrow BB.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal/wood stud.
FIG. 3B is a cross-sectional view of the embodiment of FIG. 3A along arrow CC.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment metal/wood joist, rafter and header.
FIG. 4B is a cross-sectional view of the embodiment of FIG. 4A along arrow DD.
FIG. 5A is a top perspective view of a fifth embodiment track for metal/wood stud systems.
FIG. 5B is a bottom perspective view of the embodiment of FIG. 5A along arrow El.
FIG. 5C is a cross-sectional view of the embodiment of FIG. 5B along arrow EE.
FIG. 6A is a perspective view of a sixth preferred embodiment metal/wood band.
FIG. 6B is a cross-sectional view of the embodiment of FIG. 6A along arrow FF.
FIG. 7 cross-sectional view a framing system utilizing the embodiments of FIGS. 1A-6B.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
The preferred method of calculating thermal transmittance for building assemblies with integral steel is the zone method published by the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE). A recent study by the National Association of Home Builders Research Center and Oak Ridge National Laboratory verified the usefulness of the zone method for calculating thermal transmittance for light gauge steel walls.
Thermal transmittance calculations were completed using the zone method for the metal/wood stud invention embodiments. Table 1 shows a comparison of thermal transmittance (given as total R-value) for nine wall configurations. The first wall listed is a conventional 2×4 wood frame wall with 1/2" plywood sheathing and R-11 fiberglass cavity insulation. The total wall R-value is 13.2 hr-F-ft 2 /Btu. the second and third walls listed are conventional metal stud walls, one with 1/2" plywood sheathing (R-7.9) and the other with 1/2" extruded polystyrene sheathing (R-11.4). With conventional metal studs, high resistivity insulated sheathing is necessary to limit the large loss of total thermal resistance when low resistivity sheathings are used. In some cases, it is not desirable to use the non-structural insulated sheathing, such as when brick ties are needed, or when higher racking resistance is needed.
In comparison, the metal/wood stud walls corresponding to those described in the subject invention has a 43 percent greater total R-value than the conventional stud wall when using plywood sheathing. Thermal performance of the metal/wood stud wall with plywood sheathing is nearly the same as the conventional wall with 1/2" extruded polystyrene (XPS insulated sheathing). Where non-structural sheathing is acceptable, fiber board sheathing, which is much less expensive than plywood, further increases the total R-value of the metal/wood stud wall.
TABLE 1__________________________________________________________________________COMPARISON OF THERMAL TRANSMITTANCE FOR CONVENTIONALMETAL STUD WALL AND NOVEL METAL/WOOD STUD WALL Stud Size Stud Spacing Cavity Exterior TotalDescription Inch Inch O.C. Insulation Sheathing R-Value__________________________________________________________________________1. Conventional metal stud,* 1.625 × 3.625 24 R-11 1/2" plywood 7.92. Conventional metal stud,* 1.625 × 3.625 24 R-11 1/2" XPS 11.43. Novel metal/wood stud, 1.5 × 3.5 24 R-11 1/2" plywood 11.34. Novel metal/wood stud 1.5 × 3.5 24 R-13 1/2" plywood 12.85. Novel metal/wood stud 1.5 × 3.5 24 R-15 1/2" plywood 14.26. Novel metal/wood stud 1.5 × 3.5 24 R-11 1/2" fiber board 12.17. Novel metal/wood stud 1.5 × 3.5 24 R-13 1/2" fiber board 13.68. Novel metal/wood stud 1.5 × 3.5 24 R-15 1/2" fiber board 15.0__________________________________________________________________________ *Conventional metal stud values from "Thermodesign Guide for Exterior Walls, American Iron and Steel Institute, Washington, D.C., Pub. No. RG9405, Jan. 1995. Comparison of vertical, transverse, and racking load capacities of 2 × 4 wood stud, metal stud, and subject invention wood/metal composite stud. Structural analysis by Kim McLeod, P.E. Of Keymark Enterprises, Boulder, Colorado.
Summary calculation results compared the allowable axial load for stud elements subjected to combined loading with axial and bending components. The three elements analyzed were a conventional 2×4 wood, a conventional 20 gauge steel stud, and the present invention metal/wood composite stud. All elements were 8' tall, and spaced 16" O.C.. Wind (transverse) load at 110 mph. Table 2 shows that the metal/wood composite section can support 54% more weight than the metal stud, and 250% more weight than the wood stud. This gives the opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required, or for reducing the amount of steel used in the composite section.
TABLE 2______________________________________STRUCTURAL CALCULATION RESULTS FOR NOVELMETAL/WOOD STUD 3.5" 20 Gauge 3.5" Metal/Wood 2 × 4 Wood Stud Metal Stud Composite Section______________________________________Allowable Axial 551 lb 894 lb 1378 lbLoad8' tall stud16" O.C.110 mgh wind______________________________________
FIG. 1A is a perspective isometric view of a first preferred embodiment metal/wood stud 100. FIG. 1B is a cross-sectional view of the embodiment 100 of FIG. 1A along arrow AA. Referring to FIGS. 1A-1B, embodiment 100 includes metal forms 110, 120 such as but not limited to 20 gauge steel has been cold-formed in a roll press into a cross-sectional channel J-shape. Each form 110, 120 includes steel web portions 112, 122 that have staggered rows of cut-out portions 115, 125 which are of a pressed tooth type triangular shape. Web portions 112, 122 are perpendicular to flanges 116, 126 which include approximately 4 rows of raised V-shaped grooves 117, 127 running longitudinally along the exterior of the flanges 116, 126. Flange returns 118, 128 are perpendicular to flanges 116, 126. Teeth 115, 125 can be hydraulically pressed adjacent the top and bottom rear side 152 of central web board 150. Central web board 150 can be solid wood, OSB, (oriented strand board) plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, web portions 112, 122 of forms 110, 120 can be fastened to the central web board 150 by nails, screws, staples and the like, or adhesively glued. A finished metal/wood stud 100 can have a length, L1, of approximately 8 feet or longer, height H1 of approximately 3.5 to 5.5 inches, width W1 of approximately 1.5 inches. Web portions 112, 122 can have a height, hi of approximately 1.125 inches, front plate height, h2 of approximately 0.75 inches, raised grooves R1, of approximately 0.125 inches. A spacing, x1 of approximately 0.125 inches separates each flange 116, 126 from the top and bottom of central web board 150.
FIG. 2A is a perspective view of a second preferred embodiment metal/wood stud 200. FIG. 2B is a cross-sectional view of the embodiment 200 of FIG. 2A along arrow BB. Referring to FIGS. 2A-2B, embodiment 200 includes metal forms 210, 220 such as but not limited to 20 gauge steel that has been roll pressed into a cross-sectional channel right-triangular-shape. Each form 210, 220 includes outer web portions 212, 222 that have staggered rows of cut-out portions 213, 223 which are of a pressed tooth type triangular shape. Outer web portions 212, 222 are perpendicular to flanges 214, 224 which include approximately 4 rows of raised V-shaped grooves 215, 225 running longitudinally along their exterior surface. Flange returns 216, 226 are approximately 45 degrees to flanges 214, 224, and are connected to inner web portions 218, 228 each having staggered rows of cut-out portions 219, 229 which also are of the pressed tooth type triangular shape. Teeth 213, 219 and 223, 229 can be firmly pressed adjacent the top and bottom of central web board 250. Central web board 250 can be solid wood, OSB, plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, web portions 212, 218, 222, 228 can be fastened to the central web board 250 by nails, screws, staples and the like. Outer web portions 212, 222 can have a height, B1 of approximately 1.1625 inches, flanges 214, 224 can have a width, B2 of approximately 1.5 inches, flange returns 216, 226 can have a height, B3 of approximately 0.925 inches and inner web portions 218, 228 can have a height, B4 of approximately 1 inch. A finished metal/wood stud 200 can have the remaining dimensions and spacings similar to the embodiment 100 previously described, except height, B5 can be approximately 5.5 to approximately 7.25 inches.
FIG. 3A is a perspective isometric view of a third preferred embodiment metal/wood stud 300. FIG. 3B is a cross-sectional view of the embodiment 300 of FIG. 3A along arrow CC.
Referring to FIGS. 3A-3B, embodiment 300 includes metal forms 310, 320 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 310, 320 includes metal web portions 312, 322, 318, 328 that have staggered rows of cut-out portions 313, 323, 319, 329 which are of a pressed tooth type triangular shape. Web portions 312, 322, 318, 328 attach to 45 degree flange returns 314, 324 which are attached to respective flanges 315,325 which include approximately 4 rows of raised V-shaped grooves 316, 326 running longitudinally along their exterior surface. Teeth 313,319 and 323, 329 can be pressed adjacent the top and bottom of central web board 350. Central web board 350 can be solid wood, OSB, plywood and the like, having a thickness of approximately 1/2 an inch. Alternatively, metal web portions 312, 318, 322, 328 can be fastened to the central web board 350 by nails, screws, staples and the like. Metal web portions 312, 318, 322, 328 can have a height, C1 of approximately 0.875 inches, flanges 315, 325 can have a width, C2 of approximately 1.5 inches, flange returns 314, 317, 324, 327 can have a height, C3 of approximately 0.4625 inches. A finished metal/wood stud 300 can have remaining dimensions and spacings similar to the embodiment 200 previously described.
FIG. 4A is a perspective isometric view of a fourth preferred embodiment 400 useful as a metal/wood joist, rafter and header. FIG. 4B is a cross-sectional view of the embodiment 400 of FIG. 4A along arrow DD. Referring to FIGS. 4A-4B, embodiment 400 includes metal forms 410, 420 such as but not limited to 20 gauge steel has been roll pressed into a cross-sectional channel triangular-shape with parallel plates on the apex of the triangle. Each form 410, 420 includes metal web portions 412, 422, 418, 428 that have staggered rows of cut-out portions 413, 423, 419, 429 which are of a pressed tooth type triangular shape. Metal web portions 412, 422, 418, 428 attach to 45 degree flange returns 414, 424, 417, 427 which are attached to respective flanges 415, 425 which include approximately 4 rows of raised V-shaped grooves 416, 426 running longitudinally along their exterior surface. Teeth 413, 419 and 423, 429 can be pressed adjacent the top and bottom portions of central web boards 452, 454. A central metal plate 460 has left facing tooth rows 463 and right facing tooth rows 465 for connecting to adjacent respective web boards 452, 454. Plate 460 has a spacing above and below to separate such from flanges 415, 425. Central web boards 452, 454 can be solid wood, OSB, plywood and the like, having a thickness of approximately 0.375 inches. Alternatively, metal web portions 412, 418, 422, 428 can be fastened to the central web boards 452, 454 by nails, screws, staples and the like. Metal web portions 412, 418, 422, 428 can have a height, D1 of approximately 1.0188 inches, flanges 415, 425 can have a width, D2 of approximately 1.5 inches, flange returns 414, 417, 424, 427 can have a height, D3 of approximately 0.3188 inches. A finished embodiment 400 can have practically any length, L2 to serve as a floor joist, rafter or header, width D2 can be approximately 1.5 inches and height D4, can be approximately 5.5 inches or more.
FIG. 5A is a top perspective view of a fifth embodiment track 500 for metal/wood stud and track systems. FIG. 5B is a bottom perspective view of the embodiment 500 of FIG. 5A along arrow E1. Fig. 5C is a cross-sectional view of the embodiment 500 of FIG. 5B along arrow EE. Referring to FIGS. 5A-5C, embodiment 500 includes metal forms 510, 520 each having a generally L-shaped cross-section. Forms 510, 520 each include flanges 512, 522 approximately 1.125 inches in height perpendicular to metal web portions 514, 524, which are approximately 1.1625 inches in length. Metal web portions 514, 524 have tooth shaped triangular cut-outs 515, 525, which are pressed into sides of center-web-board 550. A spacing E2 of approximately 0.125 inches separates the ends of center-web-board 550 from flanges 512, 522, respectively. A finished embodiment 500 can have remaining dimensions and spacings similar to the embodiments 100, 200, and 300 above.
FIG. 6A is a perspective view of a sixth preferred embodiment metal/wood joists and bands 600. FIG. 6B is a cross-sectional view of the embodiment 600 of FIG. 6A along arrow FF. Referring to FIGS. 6A-6B, embodiment 600 includes top metal form 610 having a T-cross-sectional shape and lower metal form 620 having a straight line cross-sectional shape. Form 610 includes metal web portion 612, having a length, F1 of approximately 1.0375 inches having tooth shaped triangular cut-outs 613 which are pressed into upper end sides of wood center web board 650. Form 610 further includes an upright leg 614 having a length F2 of approximately 1.3 inches, perpendicular to a third leg 616, having a length, F3 of approximately 1.25 inches, which abuts against and overlaps top end 652 of centerboard 650. Lower metal form 620 has a metal web portion 622 having tooth shaped triangular cut-outs 623 which are pressed into upper end sides of wood center board 650, and a continuous extended plate 624. The continuous width F4, of metal plate 622, 624 is approximately 1.75 inches, with plate 624 extending a length F5 of approximately 0.75 inches from the lower end 654 of center-web-board 650 having thickness of approximately 0.5 inches. A finished embodiment 600 can have a width F6 and length L3 similar to embodiment 400.
FIG. 7 is a cross-sectional view a framing system 700 utilizing the embodiments of FIGS. 1A-6B. Embodiment 700 can be a two story building having a metal/wood bottom track 500 attached at floor 702 by conventional fasteners such as nails, screws, bolts and the like. Vertically oriented metal/wood studs 100/200/300 can be attached to floor and ceiling tracks 500 by steel framing screws 715 and the like. A metal/wood band 600 attaches first floor ceiling track 500 to metal/wood floor joist 400 and subfloor 710, which has conventional steel framing flathead type screws 716 and the like. The second floor has a similar arrangement with rafters 400 attached at conventional angles to upper metal/wood top track 500.
A cost of a metal/wood composite stud such as those described in the previous embodiment 100 is estimated to be $4.24. The lowest cost of conventional 20 gauge steel studs is $2.52 each, however, to obtain the same thermal performance, an insulated sheathing is required which raises the cost to $4.55 per stud. The metal/wood framing member's invention is directly cost effective compared to the conventional metal stud. In addition, structural calculations show that the metal/wood stud configuration can support 54% more weight at the same 8' wall height, 16" O.C. spacing, and 110 mph wind load. This give opportunity for further cost optimization by increasing the spacing which would reduce the number of studs required. For example, a 2000 square foot house framed 16" O.C. will have about 168 conventional steel exterior wall studs, the same house framed 24" O.C. with the stronger metal/wood composite exterior wall studs will use only 107 studs. With 61 fewer exterior wall studs required, the builder can save about $270.
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. For the claims, the invention will be described as having all metal portions including the forms to be referred to as flanges, and all mid wood portions will be referred to as wood web members.
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Metal and wood composites are used to create framing members (studs and tracks, joists and bands, rafters, headers and the like.) for lightweight construction. Metal is utilized for its high strength, resistance to rot and insects, cost stability, and potentially lower cost through recycling. Metal that can be used includes roll formed steel approximately 18-22 gauge. Wood is used primarily for its lower thermal conductivity, and availability. The metal components form the primary structure while wood, either solid or other engineered wood, provides some structure and a thermal break. The invention connects J-shaped or triangular shaped metal forms to wood sections. The metal flange ends can have various J, C, L, right triangular, triangular, T and straight line cross-sectional shapes. The wood is fastened to the metal by machine pressing of the metal to wood. Alternatively the fastening includes nails, staples, screws, and the like, and also by adhesive glue. The outward faces of the metal members are pre-formed with four longitudinal ridges such that the contact surface area to applied sheathings is reduced by about 90%.
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CROSS REFERENCE TO OTHER APPLICATIONS
This application is filed as a continuation-in-part of application Ser. No. 09/829,416 entitled “Toroidal and Compound Vortex Attractor”, filed Apr. 9, 2001, which is a continuation-in-part of application Ser. No. 09/728,602, filed Dec. 1, 2000, entitled “Lifting Platform”, which is a continuation-in-part of co-pending application Ser. No. 09/316,318, filed May 21, 1999, entitled “Vortex Attractor.”
TECHNICAL FIELD OF THE INVENTION
The present invention relates initially, and thus generally, to an improved vacuum cleaner. More specifically, the present invention relates to an improved vacuum cleaner that utilizes a toroidal vortex such that the air pressure within the device housing is below atmospheric. In the present invention, this prevents dust-laden air within the device from being carried to the surrounding atmosphere.
BACKGROUND OF THE INVENTION
The use of vortex forces is known in various arts, including the separation of matter from liquid and gas effluent flow streams, the removal of contaminated air from a region and the propulsion of objects. However, a toroidal vortex has not previously been provided in a bagless vacuum device having light weight and high efficiency.
The prior art is strikingly devoid of references dealing with toroidal vortices in a vacuum cleaner application. However, an Australian reference has some similarities. Though it does not approach the scope of the present invention, it is worth disusing its key features of operation such that one skilled in the art can readily see how its shortcomings are overcome by the present invention disclosed herein.
In discussing Day International Publication number WO 00/19881 (the Day publication), an explanation of the Coanda effect is required. This is the ability for a jet of air to follow around a curved surface. It is generally referred to without explaining the effect, but is simply understood provided that one makes use of “momentum” theory; a system based on Newton's laws of motion, rather than try to weave an understanding from Bernoulli.
FIG. 1 shows the establishment of the Coanda effect. In (A) air is blown out horizontally from a nozzle 100 with constant speed V. The nozzle 100 is placed adjacent to a curved surface 102 . Where the air jet 101 touches the curved surface 102 at point 103 , the air between the jet 101 and the surface 102 as it curves away is pulled into the moving airstream both by air friction and the reduced air pressure in the jet stream, which can be derived using Bernoulli. As the air is carried away, the pressure at point 103 drops. There is now a pressure difference across the jet stream so the stream is forced to bend down, as in (B). The contact point 104 has moved to the right. As air is continuously being pulled away at point 104 , the jet continues to be pulled down to the curved surface 102 . The process continues as in (C) until the air jet velocity V is reduced by air and surface friction.
FIG. 2 shows the steady state Coanda effect dynamics. Air is ejected horizontally from a nozzle 200 with speed represented by vector 201 tangentially to a curved surface 203 . The air follows the surface 203 with a mean radius 204 . Air, having mass, tries to move in a straight line in conformance with the law of conservation of momentum. However, it is deflected around by a pressure difference across the flow 202 . The pressure on the outside is atmospheric, and that on the inside of the airstream at the curved surface is atmospheric minus ρV 2 /R where ρ is the density of the air.
The vacuum cleaner coanda application of the Day publication has an annular jet 300 with a spherical surface 301 , as shown in FIG. 3 . The air may be ejected sideways radially, or may have a spin to it as shown with both radial and tangential components of velocity. Such an arrangement has many applications and is the basis for various “flying saucer” designs.
The simplest coanda nozzle 402 described in the Day publication is shown in FIG. 4 . Generally, the nozzle 402 comprises a forward housing 407 , rear housing 408 and central divider 403 . Air is delivered by a fan to an air delivery duct 400 and led 401 to an output nozzle 402 . At this point the airflow cross section is reduced so that air flowing through the nozzle 402 does so at high speed. The air may also have a rotational component, as there is no provision for straightening the airflow after it leaves the air pumping fan. The central divider 403 swells out in the terminating region of the output nozzle 402 and has a smoothly curved surface 404 for the air to flow around into the air return duct using the coanda effect.
Air in the space below the coanda surface moves at high speed and is at a lower than ambient pressure. Thus dust in the region is swept up 405 into the airflow 409 and carried into the air return duct 406 . For dust to be carried up from the surface, the pressure is preferably low and carrying the air up the return duct 406 , requires a steady airflow. After passing through a dust collection system the air is connected through a fan back to the air delivery duct. Constriction of the airflow by the output nozzle leads to a pressure above ambient in this duct ahead of the jet. In sum, air pressure within the system is above ambient in the air delivery duct and below ambient in the air return duct. The overall system is not shown, as this is not necessary to understand its fundamental characteristics.
Coanda attraction to a curved surface is not perfect, and as shown in FIG. 5, not all the air issuing from the output nozzle is turned around to enter the air return duct. An outer layer of air proceeds in a straight fashion 501 . When the nozzle is close to the floor, this stray air will be deflected to move horizontally parallel to the floor and should be picked up by the air return duct if the pressure there is sufficiently low. In this case, the system may be considered sealed; no air enters or leaves, and all the air leaving the output nozzle is returned.
When the nozzle is high above the ground, however, there is nothing to turn stray air 501 around into the air return duct and it proceeds out of the nozzle area. Outside air 502 , with a low energy level is sucked into the air return to make up the loss. The system is no longer sealed. An example of what happens then is that dust underneath and ahead of the nozzle is blown away. In a bagless system such as this, where fine dust is not completely spun out of the airflow but recirculates around the coanda nozzle, some of this dust will be returned to the surrounding air.
Air leakage is exacerbated by rotation in the air delivery duct caused by the pumping fan. Air leaving the output nozzle rotates so that centrifugal force spreads out the airflow into a cone. The results in the generation of a larger amount of stray air. Air rotation can be eliminated by adding flow straightening vanes to the air delivery duct, but these are neither mentioned nor illustrated in the Day publication.
A side and bottom view of an annular coanda nozzle 600 is shown in FIG. 6 . This is a symmetrical version of the nozzle shown in FIG. 4 . Generally, the nozzle 600 comprises outer housing 602 , air delivery duct 601 , air return duct 605 , flow spreader 603 and annular coanda nozzle 604 . Air passes down though the central air delivery duct 601 , and is guided out sideways by a flow spreader 603 to flow over an annular curved surface 604 by the coanda effect, and is collected through the air return duct 605 by a tubular outer housing 602 .
This arrangement exhibits similar behavior as previously described. Air strays away from the coanda flow, particularly when the jet is spaced away from a surface.
While it is conceivable that the performance of the invention of the Day publication would be improved by blowing air in the reverse direction, down the outer air return duct and back up through the central air delivery duct, stray air would then accumulate in the central area rather than be ejected out radially. Unfortunately, the spinning air from the air pump fan would cause the air from the nozzle to be thrown out radially due to centrifugal force (centripetal acceleration) and the system would not work. This effect could be overcome by the addition of flow straightening vanes following the fan. However, the Day publication does not disclose a means for staightening airflow.
The Day publication has more complex systems with jets to accelerate airflow to pull it around the coanda surface, and additional jets to blow air down to stir up dust and others to optimize airflow within the system. However, these additions are not pertinent to the analysis herein.
The new toroidal vortex vacuum cleaner is a bagless design and one in which airflow must be contained within itself at all times. Air continually circulates from the area being cleaned, through the dust collector and back again. Dust collection is not perfect and so air returning to the surface is dust laden. This air must, of course, contact the surface in order to pick up more dust but must not be allowed to escape into the surrounding atmosphere. It is not sufficient to design the cleaner to ensure essentially sealed operation while operating adjacent to a surface being cleaned, it must also remain sealed when away from a surface to prevent fine dust particles from re-entering the surrounding air.
Another reason for maintaining sealed operation when away from the surface is to prevent the vacuum cleaner nozzle from blowing surface dust around when it is held at a distance from the surface.
The Day publication, in most of its configurations, is coaxial in that air is blown out from a central duct and is returned into a coaxial return duct. The toroidal vortex attractor is coaxial and operates the reverse way in that air is blown out of an annular duct and returned into a central duct. The one is the reverse of the other.
The inventor has also noted the presence of cyclone bagless vacuum cleaners in the prior art. The present invention utilizes an entirely different type of flow geometry allowing for much greater efficiency and lighter weight. Nonetheless, the following represent references that the inventor believes to be representative of the art in the field of bagless cyclone vacuum cleaners. One skilled in the art will plainly see that these do not approach the scope of the present invention.
Dyson U.S. Patent No. 4,593,429 discloses a vacuum cleaning appliance utilizing series connected cyclones. The appliance utilizes a high-efficiency cyclone in series with a low-efficiency cyclone. This is done in order to effectively collect both large and small particles. In conventional cyclone vacuum cleaners, large particles are carried by a high-efficiency cyclone, thereby reducing efficiency and increasing noise. Therefore, Dyson teaches incorporating a low-efficiency cyclone to handle the large particles. Small particles continue to be handled by the high-efficiency cyclone. While Dyson does utilize a bagless configuration, the type of flow geometry is entirely different. Furthermore, the energy required to sustain this flow is much greater than that of the present invention.
Song, et al U.S. Pat. No. 6,195,835 is directed to a vacuum cleaner having a cyclone dust collecting device for separating and collecting dust and dirt of a comparatively large particle size. The dust and dirt is sucked into the cleaner by centrifugal force. The cyclone dust collecting device is biaxially placed against the extension pipe of the cleaner and includes a cyclone body having two tubes connected to the extension pipe and a dirt collecting tub connected to the cyclone body. Specifically, the dirt collecting tub is removable. The cyclone body has an air inlet and an air outlet. The dirt-containing air sucked via the suction opening enters via the air inlet in a slanting direction against the cyclone body, thereby producing a whirlpool air current inside of the cyclone body. The dirt contained in the air is separated from the air by centrifugal force and is collected at the dirt collecting tub. A dirt separating grill having a plurality of holes is formed at the air outlet of the cyclone body to prevent the dust from flowing backward via the air outlet together with the air. Thus, the dirt sucked in by the device is primarily collected by the cyclone dust connecting device, thus extending the period of time before replacing the paper filter. The device of Song et al differs primarily from the present invention in that it requires a filter. The present invention utilizes such an efficient flow geometry that the need for a filter is eliminated. Furthermore, the conventional cyclone flow of Song et al is traditionally less energy efficient and noisier than the present invention.
Thus, there is a clear and long felt need in the art for a light weight, efficient and quiet bagless vacuum cleaner.
SUMMARY OF THE INVENTION
The present invention was developed from the applicant's prior inventions regarding toroidal vortex attractors.
Described herein are embodiments that deal with both toroidal vortex vacuum cleaner nozzles and systems. The nozzles include simple concentric systems and more advanced, optimized systems. Such optimized systems utilize a thickened inner tube that is rounded off at the bottom for smooth airflow from the air delivery duct to the air return duct. It is also contemplated that the nozzle include flow straightening vanes to eliminate rotational components in the airflow that would greatly harm efficiency. The cross section of the nozzle need not be circular, in fact, a rectangular embodiment is disclosed therein, and other embodiments are possible.
A complete toroidal vortex bagless vacuum cleaner is also disclosed. The air mover is a centrifugal pump, much like those used in certain toroidal vortex attractor embodiments. Air leaving the centrifugal pump blades is spinning rapidly so that dust and dirt are thrown to the sidewalls of the casing. Ultimately, dirt is deposited in a centrifugal dirt separation area. The air then turns upwards over a dirt barrier and down the air delivery duct. At this point, the air is quite clean except for the finest particulates that do not deposit in the centrifugal dirt separation area. These particulates circulate through the system repeatedly until they are eventually deposited. The system operates below atmospheric pressure so that air laden with fine dust is constrained within the system, and cannot escape into the surrounding atmosphere.
Unlike other vacuum cleaners that employ centrifugal dust separation (e.g., the “cyclone” types discussed above), the present invention spins the air around at the blade speed of the centrifugal pump. Thus, the system acts like a high speed centrifuge capable of removing very small particles from the airflow. Therefore, no vacuum bag or HEPA filter is required.
One of the main features of the present invention is the inherent low power consumption. There are no losses that must exist when bags or HEPA filters are utilized. These devices restrict the airflow, thus requiring greater power to maintain a proper flow rate. The majority of the power saving, however, comes from the closed air system in which energy supplied by the pump is not lost as air is expelled into the atmosphere, but is retained in the system. The design is expected to be practically maintenance free.
Thus, it is an object of the present invention to utilize toroidal vortices in a vacuum cleaner application.
It is a further object of the present invention to provide toroidal vortex vacuum cleaner nozzles.
It is yet another object of the present invention to provide a complete toroidal vortex vacuum cleaner system.
Additionally, it is an object of the present invention to provide an efficient vacuum cleaner.
Furthermore, it is an object of the present invention to provide a quiet vacuum cleaner.
It is a further object of the present invention to provide a light weight vacuum cleaner.
In addition, it is an object of the present invention to provide a low-maintenance vacuum cleaner.
It is yet another object of the present invention to provide a bagless vacuum cleaner.
It is a further object of the present invention to provide a vacuum cleaner that does not require the use of filters.
SUMMARY OF THE DRAWINGS
A further understanding of the present invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated embodiment is merely exemplary of systems for carrying out the present invention, both the organization and method of operation of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention.
For a more complete understanding of the present invention, reference is now made to the following drawings in which:
FIG. 1, already discussed, depicts the establishment of the coanda effect (PRIOR ART);
FIG. 2, already discussed, depicts the dynamics of the coanda effect (PRIOR ART);
FIG. 3, already discussed, depicts the coanda effect on a spherical surface with both radial and tangential components of motion (PRIOR ART);
FIG. 4, already discussed, depicts a coanda vacuum cleaner nozzle (PRIOR ART);
FIG. 5, already discussed, depicts the undesirable airflow in a coanda vacuum cleaner nozzle (PRIOR ART);
FIG. 6, already discussed, depicts a side and bottom view of an annular coanda vacuum cleaner nozzle (PRIOR ART);
FIG. 7 depicts a toroidal vortex, shown sliced in half;
FIG. 8 graphically depicts the pressure distribution across the toroidal vortex of FIG. 7;
FIG. 9 depicts a toroidal vortex attractor;
FIG. 10 depicts a cross section of a concentric vacuum system;
FIG. 11 depicts a concentric vacuum system with air being sucked up the center and blown down the sides;
FIG. 12 depicts the dynamics of the re-entrant airflow of the system of FIG. 11;
FIG. 13 depicts a cross section of an exemplary toroidal vortex vacuum cleaner nozzle in accordance with the present invention;
FIG. 14 depicts a perspective view of an exemplary rectangular toroidal vortex vacuum cleaner nozzle in accordance with the present invention; and
FIG. 15 depicts a cross section of an exemplary toroidal vortex bagless vacuum cleaner having an exemplary circular plan form.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, a detailed illustrative embodiment of the present invention is disclosed herein. However, techniques, systems and operating structures in accordance with the present invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein which define the scope of the present invention. The following presents a detailed description of a preferred embodiment (as well as some alternative embodiments) of the present invention.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “in” and “out” will refer to directions toward and away from, respectively, the geometric center of the device and designated and/or reference parts thereof. The words “up” and “down” will indicate directions relative to the horizontal and as depicted in the various figures. The words “clockwise” and “counterclockwise” will indicate rotation relative to a standard “right-handed” coordinate system. Such terminology will include the words above specifically mentioned, derivatives thereof and words of similar import.
A toroidal vortex is a donut of rotating air. The most common example is a smoke ring. It is basically a self-sustaining natural phenomenon. FIG. 7 shows a toroidal vortex 700 , at an angle, and sliced in two to illustrate the airflow 701 . In a section of the vortex, a particular air motion section is shown by a stream tube 702 , in which the air constantly circles around. Here it is shown with a mean radius 703 and mean speed 704 . Circular motion is maintained by a pressure difference across the stream tube, the pressure being higher on the outside than the inside. This pressure difference Δp is, by momentum theory, Δp=ρV 2 /R where ρ is the air density, R is radius 703 and V is velocity 704 . Thus the pressure decreases from the outside of the toroid to the center of the cross section, and then increases again towards the center of the toroid. The example shows air moving downwards on the outside of the toroid 700 , but the airflow direction can be reversed for the function and pressure profile to remain the same. The downward outside motion is chosen because it is the preferred direction used in the toroidal vortex vacuum cleaner of the present invention.
FIG. 8 shows a typical pressure profile across the toroidal vortex. Shown is the pressure on axis 801 as a function of distance in the x direction 802 . Line 803 is a reference for atmospheric pressure, which remains constant along the x direction.
The present invention was developed from a toroidal vortex attractor previously described by the inventor. FIG. 9 shows a toroidal vortex attractor that has a motor 901 driving a centrifugal pump located within an outer housing 902 . The centrifugal pump comprises blades 903 and backplate 904 . This pumps air around an inner shroud 905 so that the airflow is a toroidal vortex with a solid donut core. Flow straightening vanes 906 are inserted after the centrifugal pump and between the inner shroud 905 and the outer casing 902 in order to remove the tangential component of air motion from the airflow. The air moves tangentially around the inner shroud 905 cross section, but radially with respect to the centrifugal pump.
Air pressure within the housing 902 is below ambient. The pressure difference between ambient and inner air is maintained by the curved airflow around the inner shroud's 905 lower outer edge. The outer air turns the downward flow between the inner shroud 905 and outer casing 902 into a horizontal flow between the inner shroud and the attracted surface 907 . This pressure difference is determined by ρv 2 /r where v is the speed of the air circulating 908 around the inner shroud 905 , r is the radius of curvature 909 of the airflow and ρ is the air density. The maximum air pressure differential is determined by the centrifugal pump blade tip speed (V) at point 910 , and tip radius (R) 911 (ρV 2 /R).
The toroidal vortex attractor 900 can be thought of as a vacuum cleaner without a dust collection system. Dust particles picked up from the attracted surface 907 are picked up by the high speed low pressure airflow and circulate around.
The new toroidal vortex vacuum cleaner is a bagless design and one in which airflow must be contained within itself at all times. Air continually circulates from the area being cleaned, through the dust collector and back again. Dust collection is not perfect and so air returning to the surface is dust laden. This air must, of course, contact the surface in order to pick up more dust but must not be allowed to escape into the surrounding atmosphere. It is not sufficient to design the cleaner to ensure essentially sealed operation while operating adjacent to a surface being cleaned, it must also remain sealed when away from a surface to prevent fine dust particles from re-entering the surrounding air.
Another reason for maintaining sealed operation is to prevent the vacuum cleaner nozzle from blowing surface dust around when it is held at a distance from the surface.
The toroidal vortex attractor is coaxial and operates in a way that air is blown out of an annular duct and returned into a central duct. FIG. 10 shows a system 1000 comprising outer tube 1001 and inner tube walls 1002 (which form inner tube 1003 ) in which air passes down the inner tube 1003 and returns up the outer tube 1001 . While it would be desirable that the outgoing air returns up into the air return duct 1005 , a simple experiment shows that this is not so. Air from the central delivery duct 1004 forms a plume 1007 that continues on for a considerable distance before it disperses. Thus, air is sucked into the air return duct from the surrounding area 1006 . This arrangement, without coanda jet shaping is clearly unsuited to a sealed vacuum cleaner design.
FIG. 11 shows a system 1100 having the reverse airflow of FIG. 10 . Again, system 1100 comprises outer tube 1101 and inner tube walls 1102 (which form inner tube 1103 ). Air is blown down the outer air delivery duct 1104 and returned up the central return duct 1105 . Air is initially blown out in a tube conforming to the shape of the outer air delivery duct 1104 . As this air originates in the inner tube 1103 , replacement air must be pulled from the space inside the tube of outgoing air. This leads to a low pressure zone at A, within and below the air return duct 1105 . Consequently air is pulled in at A from the outgoing air. Thus the air (whose flow is exemplified by arrows 1107 ) is forced to turn around on itself and enter the return duct 1105 . Such action is not perfect and a certain amount of air escapes 1108 at the sides of the air delivery duct, and is replaced by the same small amount of air 1106 being drawn into the air return duct 1105 .
Air interchange is reduced by the lowering of the air pressure within the concentric system. FIG. 12 shows air returning from the delivery duct 1104 into the return duct 1105 with radius of curvature (R) 1203 and the velocity at 1204 . With airspeed V at 1204 , the pressure difference between the ambient outer air and the inside is ρV 2 /R, where ρ is the air density. The airflow at the bottom of the concentric tubes is in fact half of a toroidal vortex, the other half being at the top of the inner tube within the outer casing 1101 . The system of FIGS. 11 and 12 is thus a vortex system, with a low internal pressure and minimal mixing of outer and inner air.
The simple concentric nozzle system shown in FIGS. 11 and 12 can be optimized into an effective toroidal vortex vacuum cleaner nozzle 1300 depicted in FIG. 13 . The inner tube 1301 is thickened out and rounded off at the bottom (inner fairing 1306 ) for smooth airflow around from the air delivery duct 1302 to the air return duct 1303 . The outer tube 1304 is extended a little way below the inner tube 1301 end and rounded inwards somewhat so that air from the delivery duct 1302 is not ejected directly downwards but tends towards the center. This minimizes the amount of air leaking sideways from the main flow. The nozzle has flow straightening vanes 1305 to eliminate any corkscrewing in the downward air motion in the air delivery duct 1302 that would throw air out sideways from the bottom of the outer tube 1304 due to centrifugal action. When compared to the coanda nozzles of the prior art, the vortex nozzle 1300 has less leakage and has a much wider opening for the high speed air flow to pick up dust.
The vortex nozzle has so far been depicted as circular in cross section, but this is not at all necessary. FIG. 14 shows a rectangular nozzle 1400 in which the ends are terminated by bringing the inner fairings 1401 to butt against the outer tube 1402 . Air is delivered via the delivery duct 1403 and returns via the return duct 1404 . Flow straightening vanes are omitted from FIG. 14 for clarity, but are, of course, essential. An alternate system, not shown, is to carry the nozzle cross section of FIG. 13 around the ends, as there will be some air leakage around the flat ends.
FIG. 15 shows the addition of a centrifugal dirt separator, yielding a complete toroidal vortex vacuum cleaner 1500 . Again, the ducting is created by an inner tube 1507 placed concentrically within outer tube 1508 . Airflow through the outer air delivery duct 1502 , the inner air return duct 1503 and the toroidal vortex nozzle 1506 (comprising flow straightening vanes 1504 and inner fairing 1505 ) are as described previously in FIGS. 12, 13 and 14 . The air mover is a centrifugal air pump (as in the toroidal vortex attractor of FIG. 9) comprising motor 1509 , backplate 1510 and blades 1511 . Air leaving the centrifugal pump blades is spinning rapidly so that dust and dirt are thrown to the circular sidewall of the outer casing 1512 . Air moves downward and inwards to follow the bottom of the dirt box 1501 so that dirt is precipitated there as well. The air then turns upwards over a dirt barrier 1513 and down the air delivery duct 1502 . At this point, the air is clean except for fine particulates that fail to be deposited. These circulate through the system repeatedly until they are finally deposited out. The system operates below atmospheric pressure so that air laden with fine dust is constrained within the system and cannot escape into the surrounding atmosphere. After use, the dirt that has been collected in the dirt box 1501 can be emptied via the dirt removal door 1514 .
FIG. 15 depicts a circular nozzle 1506 , but the system works equally well with the rectangular nozzle of FIG. 14 . Various nozzle shapes can be designed and will operate satisfactorily, providing that the basic cross section of FIG. 13 is used.
This embodiment has air mixed with dirt and dust passing through the centrifugal impeller vanes. If such an arrangement is considered undesirable, the addition of a trap for large debris may be inserted into the air return path upstream of the impeller.
While the present invention has been described with reference to one or more preferred embodiments, which embodiments have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, such embodiments are merely exemplary and are not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention.
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Disclosed are improved vacuum cleaning apparatus that utilize toroidal vortex air flow in order to establish a pressure differential capable of attracting debris. These systems differ significantly from prior vacuum cleaners in that they are essentially closed systems; there is no constant intake and exhaust of fluid. Disclosed herein are toroidal vortex vacuum cleaner nozzles that function with a fluid delivery system, which, in combination, yield a toroidal vortex that is split between the extreme ends of the nozzle. Also disclosed is a complete toroidal vortex vacuum system employing a centrifugal dirt separator. The present invention excels in being more efficient, lighter weight and quieter than the prior art.
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RELATED PRIOR PATENTS
[0001] In my prior patents, viz., U.S. Pat. No. 5,437,239 and U.S. Pat. No. 5,707,709, there are set forth fabrics, processes and uses involving at least one stretchable layer that is stretched during formation and then allowed to relax thereafter. As a result, a series of puffs are formed in rows across the layers normal to the axial stretch direction and in columns. The columns of puffs of even numbered rows are aligned with each other with each other but are laterally offset with respect to puffs of odd numbered rows a constant amount thereby creating an aesthetically pleasing finished fabric. It has now been discovered that if the stretchable layer is stretched in both the axial and laterial directions—simultaneously—during formation, there is improved throughput while retaining an aesthetically pleasing finished fabric.
SCOPE OF THE INVENTION
[0002] This invention relates to an improved puffed, quilt-like smocked fabric consisting of a series of layers stitched together in automated manner. In one aspect of the invention, only two layers are used and the second interior layer is fed from a roller via a series of positive acting driver rollers wherein the second layer is stretching in both the axial and laterial directions simultaneously, as lateral direction (or y direction)are thus separately controlled such that the elongation factors Ax and By are additive to define a total elongation that is in the range of 1.25 to 3.00 normalized to the relaxed state of the second layer. In another aspect of the invention, three layers are used in which first and second exterior layers overlay a soft interior layer wherein the second layer undergoes axial and lateral elongation. That is to say, the three layers are fed from a roller via a series of positive acting driver rollers wherein the second layer is stretching in both the axial and lateral directions simultaneously, as stitching occurs. Again, elongations in the axial direction (or x direction) and in the lateral direction (or y direction)are separately controlled such that the elongation factors Ax and By are additive to define a total elongation in the range of 1.25 to 3.00 times the normal relaxed state of the second layer.
[0003] The stitching head undergoes cam controlled lateral movement as a function of axial movement of the layers comprising the fabric of the invention. Result: a saw-toothed stitch pattern is defined when viewed from the second layer but creating worm-like folds when viewed from the outer layer.
DEFINITIONS
[0004] These terms are used in this document and are defined as follows:
[0005] SMOCKING—A decorative stitching used in gathering cloth to make it hang in folds.
[0006] QUILT—To stitch together as two pieces of cloth with a soft innerlayer in lines or patterns of square, longitudinal or lateral extending lines.
[0007] FABRIC—Cloth formed by fibers by the processes of weaving, knitting, pressing etc., wherein the fibers can be formed from naturally occurring products such as wool , hair, cotton, flax, hemp or can be formed of synthetic fibers.
[0008] FIBER—The fundamental unit used in the fabrication of textile yarns and fabrics. A unit used in the fabrication of textile yarns and fabrics. A unit of matter characterized by having a length at least 100 times its diameter or width, and having definitely preferred orientation of its crystal unit cells with respect to a specific axis.
[0009] SYNTHETIC TEXTILES—A group of man-made fibers made by chemical synthesis or by chemical compounds through interaction.
[0010] STRETCH FABRICS—Cloths that have properties of elongation and recovery from using Spandex and like yarns.
[0011] STRETCH YARNS—Specially treated, synthetic continuous filament yarn. Examples: giving torque or false twist; by deforming them. Merits are rapid and near completed recovery and improved holding power.
[0012] TRIAXIAL STRETCH FABRIC—Cloths that have the ability to stretch and recover along x, y and bias axes in equalized segments, i.e., segment measurements per common length per common tensile force per x, y or bias directions are equalized.
[0013] BIAXIAL STRETCH FABRIC—Cloths that have the ability to stretch and recover along both the bias axis and one of the x or y axis is minimum.
[0014] YARN—A continuous string of textile fibers such as spun or continuous filament yarns. Spun yarn is short fibers while the latter is a grouping of endless parallel continuous filaments, its the basic material made into fabric, thread, twine or cable. It can be woven, knotted, crocheted, tatted, netted or braided depending on the result desired and the character of the yarn. Continuous filament yarns are formed of rayon, nylon and other synthetic textiles.
[0015] YARN NUMBER—A conventional measure of fineness of yarn. In spun yarns, a lower number means the heavier the yarn while a higher number refers to finer-sized yarns. Man-made fibers are measured in deniers and is the reverse of the above, viz., lower number means finer-sized yarns and vice versa.
BACKGROUND OF THE INVENTION
[0016] In my prior patents, viz., U.S. Pat. No. 5,437,239 and U.S. Pat. No. 5,707,709, there are set forth fabrics, processes and uses involving at least one stretchable layer that is stretched during formation and then allowed to relax thereafter. As a result, a series of puffs are formed in rows across the layers normal to the axial stretch direction and in columns. The columns of puffs of even numbered rows are aligned with each other with each other but are laterally offset with respect to puffs of odd numbered rows a constant amount thereby creating an aesthetically pleasing finished fabric. It has now been discovered that if the stretchable layer is stretched in both the axial and lateral directions-simultaneously-during formation, there is improved throughput while retaining an aesthetically pleasing finished fabric.
SUMMARY OF THE INVENTION
[0017] The present invention relates to an improved puffed, smocklike quilted fabric consisting of at least a natural resilient first layer such as velvet, silk or denim overlaying a stretchable second layer. These layers are stitched together in an automated manner. The second layer is a synthetic long chain polymer comprising at least 85% of a segmented polyurethane called “Spandex”, and is fed from a roller via positive pulling and shaping roller system that includes a lateral shaping quide and axial pulling driver roller acting through a series of pole rollers. Result: the second layer undergoes stretching in both the axial and lateral directions simultaneously, as stitching occurs. Elongations in the axial direction (or x direction) and in the laterial direction (or y direction) are defined elongation factors Ax and By which are additive to define a total elongation in the range of 1.25 to 3.00 times the normal relaxed state of the second layer as the passes through a multiple stitching head. The stitching head undergoes cam controlled lateral movement as a function of axial movement of the fabric to provide a puffed, smock-like quilted fabric. The fabric is well adapted for use in making garments such coats as well a coverings for pillows and automotive seats.
[0018] The biaxial stretching capacity of the second layer is normally between 600 to 700% of its normal relaxed state. Hence axial and lateral stretching forces that are applied to the second layer in the range of 1.25 to 3 times the relaxed state, is easily achieved. Note that previously it was explained that the second layer is called by the generic name “Spandex”. Spandex itself is defined as a manufactured fiber in which the fiber-forming substance is a long chin synthetic polymer comprising at least 85% of a segmented polyurethane (Source: FTC). Examples are Lycra, Glospan and Numa, all trademarked fabrics, In the manufacturing process of Lycra, a trademark of DuPont Company, the segmented polyurethane structure is achieved by reacting dilsocyanates with long chain glycols which are usually polyester or polyethers of 1000 to 2000 molecular weight range. The reaction product is then chain extended through the use of glycol, diamine or water. This gives the final polymer which is converted into fibers by dry spinning. In the finished fiber the chains are randomly oriented and when stretched, the chains become oriented but exhibit spontaneous recovery to the disordered state upon release of the force acting on the fiber.
[0019] During manufacture of the fabric of the invention, the second layer formed of “Spandex” is wound on a roller. The roller is controlled via a positive pulling and shaping roller system that includes a lateral shaping quide and axial pulling driver roller acting in concert with a series of pole rollers. Result: the second layer undergoes stretching in both the axial and lateral directions simultaneously, as stitching occurs. The pulling and shaping roller system also provides uniform movement of the first (upper) layer but only in an axial direction without positive braking pressure being applied. The roller containing the first and second layers are pulled toward the multiple sewing head by a roller adjacent to a lateraling shaping guide and thence through a series of pole rollers to a take-up roller.
[0020] The multiple sewing head is provided with a cam assembly the provides of lateral movement of the plurality of threaded needles to provide side-by-side sinusoidal line patterns. The plurality of threaded needles are divided into a first set provided with common lateral movement through a first cam and cam follower subassembly. Between neighboring needles of the first set, there is provided a needles of the second set. Such needles is provided with opposite movement through a second cam and cam follower subassembly. As a result, its sinusoidal line pattern is complementary to line pattern of the first set. After the quilted fabric passes downstream of the driver, the second layer of Spandex is permitted to return to it relaxed state and the finished fabric is wound about a final roller. The finished fabric as viewed from the first layer in its relaxed state comprises rows of elongated puffs extending above a base line and of uniform length normal to the precursor initial stretch direction of the second layer defined during sewing. The ends of adjacent puffs of any row are crimped by stitching so that any one row of puffs resembles a string of attached wieners. Between successive rows, the crimped ends of the puffs of one row are offset relative to he crimped ends of its next adjacent neighboring row of puffs. Thus, the columns of puffs of every other row are aligned but successive columns are offset. As a result, an aesthetically pleasing fabric is formed that has be useful in making coats (the rows of puffs running in vertical manner from the neck toward the belt and sleeves) and in padding walls of a casket as well as a covering for pillows and automotive seats.
BRIEF DESCRIPTION OF DRAWINGS
[0021] [0021]FIG. 1 is a schematic view illustrating the process by which invention is performed including a series of rollers carrying thereon first and second layers in an axial direction toward a sewing head, the laying being pulled in a positive sense by a positive roller adjacent to a lateral shaping guide thence through the sewing head and then onto a take-up roller;
[0022] [0022]FIG. 2 is an end view, partially cut-away, of the take-up roller about the second layer is wound having a braking system;
[0023] [0023]FIG. 3 is a detail side view, partially schematic, of the cam assembly for providing bilateral, independent movement of the two sets of needles comprising the multiple needle head wherein sinusoidal stitching pattern is provided the layers passing adjacent to the needles head;
[0024] [0024]FIG. 4 is a plan view of the puffed fabric wound of he take up roller of FIG. 1 in which the second layer is in relaxed state:
[0025] [0025]FIGS. 5 and 6 are vertical sections taken along line 5 - 5 and 6 - 6 , respectively, of FIG. 4;
[0026] [0026]FIG. 7 is bottom view of the puffed fabric of FIG. 4;
[0027] [0027]FIG. 8 is a plan view of the puffed fabric of FIG. 4;
[0028] [0028]FIG. 9 is a bottom view of the puffed fabric of FIG. 4;
[0029] [0029]FIG. 10 is a front view of a buttoned coat constructed with the puffed fabric of the invention in which rows of puffs run in a vertical manner;
[0030] [0030]FIG. 11 is a front view of the coat of FIG. 10;
[0031] [0031]FIG. 12 is a top view of a covering that is used to cover a pillow or an automotive seat;
[0032] [0032]FIG. 13 is a front perspective view of the lateral guide of the pulling and shaping system of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0033] [0033]FIG. 1 illustrates in schematic fashion, an assembly 9 by which the process of the present invention is performed. As shown, a series of rollers 10 , 11 , 12 , and are depicted upstream of a multiple sewing head assembly 14 and together with lateral guide 13 comprise a pulling and guiding assembly 8 . The function of the pulling guiding assembly 8 is explained in more detail below. Downstream from the sewing head assembly 14 is a series of pole rollers 15 a , 15 b , and 15 c and take-up roller 16 . A non-stretch layer 20 such as velvet, silk and/or denim is wound about the roller 10 and is fed upward toward the sewing head assembly 14 via drive roller 11 i in contact with upper surface 20 a of the layer 20 . A stretchable layer 22 is wound about feed roller 12 and travels upward into contact with the non-stretch layer 20 at the driver roller 11 . A lower surface 22 a of the stretchable layer 22 is placed in contact with lateral guide 13 and is forced into lateral stretching as explained below. Suffice to say, the layers 20 , 22 pass between the drive roller 11 and lateral stretching guide 13 so that they are placed in planar face-to-face relationship with the non-stretch layer above the stretchable layer 22 but the stretchable layer 22 undergoes both axial and lateral stretching. That is to say, as the layers 20 , 22 pass between the positive roller 11 and the lateral guide 13 under positive axial pressure (because of positive axial pressure applied by the roller 11 ), the stretchable layer 22 passes over arcuate surface 13 a of the lateral guide 13 and is undergoes lateral stretching.
[0034] [0034]FIG. 13 shows how lateral stretching occurs.
[0035] As shown, the lateral guide 13 includes a series of ridges 13 b across the surface 13 a which are shaped so that the right-hand set 5 spirals to the right as viewed starting from edge 13 d , and the left-hand set 6 spirals to the left. Result: assuming that centerlines of the layer 22 coincides with centerline 13 e of the guide 13 , lateral stretching occurs as a function of the angle A of the ridges 13 b in the manner of arrows 4 . Attachment of the lateral guide 13 is via threads of bolts 13 c attached at upper edge 13 e.
[0036] Returning to FIG. 1, the formed layers 20 , 22 pass between the sewing head assembly 14 under the positive axial and lateral pressure provided by roller 11 and lateral guide 13 . The rollers 10 and 12 are thus unwound under the positive forces applied thereto by the latter at the downstream side of the sewing head assembly 14 . The roller 12 is provided with conventional tension controls for holding proper tension on the layer 22 . The same tension is also applied to positive pole rollers 15 a , 15 b and 15 c on the upstream stream side of the sewing head assembly 14 . Once in rotation, the rollers 10 , 11 and 12 tend to rotate with constant velocities. In this regard, the rollers 10 and 12 include braking assembly 30 , as shown in FIG. 2. The purpose of the braking assembly 30 : to cause biaxial stretching of the lower layer 22 wound about roller 12 (see FIG. 1) in an amount 25 to 300% of the relaxed state of the layer 22 , as previously mentioned, as well as to cause 0% elongation of the top layer 20 . After the lower layer 22 is permitted to relax the finished fabric 17 of the invention is wound about take-up roller 16 .
[0037] [0037]FIG. 2 shows the braking assembly 30 in more detail. As shown, FIG. 2 relates to roller 12 but the description which follows is also germane to similar braking assemblies associated with the roller 10 . As shown, end 31 of the roller 12 rotates within a stationary drum 32 attached to upright standard 33 . The drum 32 has an end wall 34 and side wall 35 that extend adjacent to the end 31 of the roller 12 . The end wall 34 includes a hub 36 that attaches to the upright standard 33 . Note that the circumferencial side wall 34 extends over a portion of the circuferential surface 37 of the roller 12 . An arcuate brake pad 38 is placed in contact with outer surface 37 of the roller 12 and is capable of radial movement in the direction of arrow 39 via bolts 40 having interior ends that butt against the pad 38 . As shown, the bolts 40 attach to and through threaded openings (not shown) in the side wall 35 of the drum 32 . Note that the tension applied by the separate brake assemblies 30 to the rollers 10 and 12 of FIG. 1 is separately adjustable. The purpose of the adjustments: to cause biaxial stretching of the lower layer 22 in an amount 25 to 300% of the relaxed state of the layer 22 , as previously mentioned as well as to cause 0% elongation of the top layer 20 . Since the amount of tension for the rollers 10 , 12 is constant, the maximum braking or friction force for rollers 10 , 12 is a function of the elongation strength of the layers 20 , 22 . However, such tension force is below the ultimate strength of the layer 20 but is sufficient to provide between 25 to 300% elongation of the layer 22 .
[0038] Returning to FIG. 1, while the sewing head assembly 14 is typical for the purpose of stitching the layers 20 - 22 together using side-by-side needle bars 49 a , 49 b having separate side walls 46 into which needles 47 are attached. The needle bars 49 a , 49 b are also controlled to undergo separate, lateral movement, however. The direction of such lateral movement is depicted by arrow 50 in FIG. 3. In addition, the needles 47 of the needle bars 49 a , 49 b also undergo typical vertical movement in the direction of arrow 51 . As a result, thread releasably attached to the needles 47 is caused to enter the layers 20 , 22 to provide typical stitching patterns 53 , 54 of FIGS. 8 and 9 as viewed from the top layer 20 and bottom layer 22 , respectively.
[0039] Lateral movement of the needle bars 49 a , 49 b is depicted in detail in FIG. 3.
[0040] As shown, the needle bar 49 a has an end 55 forming a cam follower surface in contact with surface 57 of cam subassembly 58 . The end 55 is provided positive surface tension via spring 60 so that the interaction of the shape of the surface 57 of the rotating cam 58 a of the cam subassembly 58 provides for left-hand stitchings 53 a , 54 a of the patterns 53 , 54 respectively shown in FIGS. 8 and 9. Returning to FIG. 3, note that needle bar 49 a is open along its bottom edge 59 . As a consequence the needles 47 associated with the needle bar 49 a form a first set, while the needles 47 associated with the needle bar 49 b forms a second set. Between neighboring needles 47 of the first set, there is a needle 47 of the second set controlled by needle bar 49 b.
[0041] That is to say, the needle bar 49 b has an end 64 forming a cam follower surface in contact with surface 67 of cam 68 a of cam subassembly 68 . The end 64 is provided positive surface tension via spring 69 so that the interaction of the shape of the surface 67 of the rotating cam 68 a of the cam subassembly 68 provides for the right-hand stitchings 53 b , 54 b of the patterns 53 , 54 , respectively shown in FIGS. 8 and 9. Note in FIGS. 8 and 9 that uniform tension has been applied to the finshed fabric 17 in the direction of arrow 60 to provide biaxial stretch as the needle bars 49 a , 49 b move laterally to the direction of application of the tensil force (T), see FIG. 1. In addition, the seam patterns 53 , 54 are seen each to be sinusoidal-like in plan view, oscillating about axes of formation 62 wherein peaks 53 b , 54 b and troughs 53 c , 54 c of side-by-side seams laterally coincide in a direction normal to arrow 60 .
[0042] As a result of the relative stetching of the layer 22 as the complementary sinudoidal stitch patterns 53 , 54 of FIGS. 8 and 9 are laid down, there is provided a series of improved puffs 70 of the surface of layer 20 and in layer 22 as shown in FIGS. 4 and 7, respectively. Note that in FIG. 4, the puffs 70 are shaped as shown as soon as the the pre-tensioning force in the direction of arrows 60 in FIGS. 8 and 9 are released and the layer 22 of FIG. 7 is permitted to relax as the finished fabric 17 of FIG. 1 is wound about take-up roller 16 . Note that the puffs 73 appear on the surface of the layer 20 and layer 22 as shown in FIGS. 4 and 7, respectively.
[0043] [0043]FIGS. 5 and 6 are sections that illustrate the shape of the puffs 70 in more detail as viewed along columnar lines 5 - 5 and 6 - 6 of FIGS. 5 and 6, respectively.
[0044] Note in FIG. 5 that the section is taken through rows R 1 , R 2 . . . Rx of the puffs 70 of FIG. 4 such that the section line of the odd rows R 1 , R 3 , R 5 . . . passes through arcuate ends 71 of the puffs 70 of such odd rows. Thus the puffs 70 of the odd numbered rows R 1 , R 3 . . . in FIG. 4 are columnarly aligned. Also the puffs of the even numbered rows R 2 , R 4 . . . are columarly aligned but offset from puffs 70 of the odd numbered rows R 1 , R 3 . . . But the section line is seen to also bisect the puffs 70 of the even rows R 2 , R 4 . . . at maximum height h of each puff 70 . As a result, the puffs 70 of the even rows R 2 , R 4 . . . define cavities 72 between top and bottom layers 20 , 22 .
[0045] While the layers 20 22 forming the puffs 70 of the odd rows R 1 , R 3 . . . follow the same contour so that the cavities 73 are of minimum volume.
[0046] Note in FIG. 6 that the section is taken through rows R 1 , R 2 . . . Rx of the puffs 70 at a columnar location in which the height h of the puffs 70 is seen to be essentially constant from row-to-row. Moreover, the cavities 72 , 73 of the rows R 1 , R 2 , R 3 . . . are of the same shape and volume. The cavities 72 , 73 are formed between top and bottom layers 20 , 22 .
[0047] But referring again to FIG. 4, the puffs 70 of odd numbered rows R 1 , R 3 , R 5 . . . are seen to be columnarly aligned. Also the puffs 70 of the even numbered rows R 2 , R 4 , R 6 . . . are likewise columnarly aligned but are offset from puffs 70 of the odd numbered rows R 1 , R 3 . . . by a constant amount, say equal to L/2 where L is the length of each puff 70 .
[0048] [0048]FIGS. 10 and 11 illustrate a garment 80 in the form of a jacket comprising an outer shell 81 formed of the finished fabric 17 associated with take-up roller 16 , see FIG. 1. The outer shell 81 has a pair of front panels 82 , 83 attached to a waistband 79 and a rear panel 85 . The rear panel 85 is attached to the front panels via shoulder seams 84 . Sleeves 86 are also a component of the outer shell 81 and are attached via an arcuate set of seams 87 to the front and rear panels 82 , 83 and 85 . An attached collar 86 , front button bands 87 , 88 and inner liner 89 , complete the garment 80 . The collar 86 attaches to the upper edges of the front and rear panels 82 , 83 and 85 . The button bands 87 , 88 attach vertically between the collar 86 and the waistband 79 and laterally via side edges 90 of front panels 82 , 83 . Note that the puffs 70 of the outer shell 81 has rows R 1 , R 2 , R 3 . . . that run generally in a vertical pattern between the waistband 79 and the collar 86 . As a result, the vertical line of the puffs 70 is generally slimming to the user and pleasing to the eye of the on-looker.
[0049] [0049]FIG. 12 is a top view of a cover 92 for use in association with a pillow or with an automotive seat. If the cover 92 is used with a pillow, the cover 92 would include both front and rear panel 93 , 94 but for use in covering an automotive seat, the cover 92 would only include a single panel 93 or 94 but not both. Each such panel 93 or 94 includes top and bottom edges 96 , 97 and a pair of side edges 98 . If used in association with pillow, the panels 93 , 49 are attached via top and bottom seams 99 and side seams 100 . The resulting puffs 70 of the cover 92 run generally parallel to the top and bottom edges 96 , 97 so as to be pleasing to the eye of the on-looker.
[0050] While preferred embodiments have been shown and described in the foregoing, it will be understood that the invention is capable of numerous modifications, rearrangements and substitutions without departing from the spirit of the invention as set forth in the appended claims. For example, the invention is capable of being carried out using a quilting machine manufactured by Edgewater Machine Company, 13-20 131st St., College Park, N.Y. wherein such machine is modified to provide correct braking of the layers of material prior to sewing and to provide correct movement of the sewing head relative to such layers as sewing occurs.
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In the proces of defining quilted fabric, non-stretchable, stretchable and interior layers of materials are wound on separate rollers. Then the layers are positively fed from the rollers to a bi-directional acting sewing assembly wherein the non-stretchable layer is provided with zero elongation and the stretchable layer is provided with 25 to 300 percent stretch. Next, the arranged layers are sewn in sets of sinusoidal-like seam patterns. Finally the stretched layer is permitted to relax to a natural state wherein a series of puffs are formed in rows across the layer normal to stretch direction of the stretchable layer. Result: columns of puffs of even numbered rows are aligned with each other but are laterally offset with respect to puffs of odd numbered rows by a constant amount.
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CROSS-REFERENCE
This application claims the benefit of priority from U.S. Provisional Application Ser. No. 60/926,139 filed Apr. 25, 2007, and entitled “Multi-Level Filter Device”.
FIELD OF THE INVENTION
The present invention is directed to filters used to separate suspended solids in a liquid solution. More specifically, the present invention is directed to methods and apparatuses for filtering septic tank effluent.
BACKGROUND
A number of different filtering devices are known for separating solid matter from water, such as, for example, waste water in septic tanks. Many of the known devices for removing waste water from septic tanks allow the solid materials to settle to the bottom of the tank and allow bacteria to react and digest the solid materials. The by-products of the reaction of the solid or semi-solid matter with the bacteria then pass through filtration to remove the remaining small particles, with the waste water being removed by overflow or by discharge pumps in to a drain field. Known filtration systems employ a filter cartridge having a stack of settling plates with a weir wall integral to the top side of the settling plate. Such known filters, however, only have one level of filtration or screening. Therefore, any solids smaller than the aperture either pass onto the drainfield or become trapped on the settling plate requiring more frequent servicing. Other known systems employ a filter that has a stack of inclined filter plates that have an integral weir wall extending from the settling plate. This design allows solids to side to slide back down the inclined surface before passing through the aperture. However, in these known designs smaller particles that pass through the aperture become trapped inside by the weir wall and again require frequent servicing.
SUMMARY OF THE INVENTION
The filter of the present invention solves the recognized problems in the field by, among other advantages, creating multiple apertures between any two settling plates. This is accomplished by making the weir wall as a separate component that is inserted between two inclined settling plates, thus allowing solid and semisolid masses larger in size than the apertures to settle on the inclined plates and then slough back into the septic tank. When solids build up and eventually block the aperture below the weir wall, the flow can continue through the filter by flowing through the aperture above the weir wall. In another embodiment of the present invention a third aperture can be formed into the weir wall itself. This can lead to double, or triple the time between servicing and cleaning of the filters. This saves the homeowner significant time and cost, while insuring that their drainfields are protected from excessive solids.
Separating the partition or weir wall from being a part of either the top or bottom surface of the settling plate, and creating a plurality of apertures in the weir wall allows for at least doubling the filter area. By adding in additional apertures into the weir wall itself, at discrete locations on the wall, even more filtration area in the same size cartridge is provided. The separation of the weir walls into completely separate, or discrete system components makes for less expensive production of multiple filter models with varying levels of filtration. Instead of having to produce molds for different filter plates, one only has to make different inserts. By creating multiple partition walls with progressively finer levels of filtration, the service interval required is greatly increased. This also allows for a greater level of filtration to be accomplished per filter with less servicing and/or down time required. Currently, to accomplish this, multiple filters must to be installed in series at great expense to the consumer.
In addition, in known field filtration systems, the alarms used for filters do not give a true indication of the capacity left in the filters, as the alarm switch for these filters can only be located on the unfiltered side of the filter. The present invention allows this alarm switch to be located on the downstream side of the first filter partition. Thus, the filter is protected from having “gross” solids attach to the switch and causing a false alarm situation.
In one embodiment, the present invention provides methods and apparatuses for filtering effluent comprising providing a filtering assembly, said assembly comprising at least one substantially planar component attached to at least one partition. The planar component and the partition are attached to create at least one aperture having a predetermined dimension, with the planar components positioned at an incline. A housing is dimensioned to receive the filtering assembly, with the housing comprising an inlet and an outlet and a means for positioning said assembly within said housing. An effluent flow is then provided to the assembly in the housing and flows through the assembly such that only the effluent having predetermined characteristics moves past the partitions and angled planar surfaces.
In a further one embodiment, the present invention provides methods and apparatuses for filtering effluent comprising providing a filtering assembly, said assembly comprising a first and second substantially planar component, said first and second planar components spaced apart by at least a first and second partitions, said partitions each comprising one or more apertures, said apertures bounded partially by a surface of the first or second planar components, with said planar components positioned at an incline, or angle. A housing is provided dimensioned to receive the filtering assembly, said housing comprising an inlet and an outlet and a means for positioning the filtering assembly within said housing. An effluent flow is provided to the assembly in the housing and is directed through the filtering assembly such that the only effluent having predetermined characteristics moves past the partitions and angled planar surfaces. Solid or semisolid material of a predetermined dimension is retained in the filtering assembly, while solids or semisolids having a dimension less than said predetermined dimension, and/or liquid effluent, is allowed to pass through the filtering assembly. In a preferred embodiment, a series of filter assemblies are maintained in the housing in a stacked orientation, and at least one partition further comprises an additional integral aperture, located at a distance from the apertures located about the perimeter of the partition. The integral apertures are preferably completely bounded by the partition.
According to a further embodiment of the present invention, the partitions have similar or varying dimensions from each other, or preferably comprise spacers extending from the edges thereof, such that the first partition, when in position with a planar component provides apertures having a first dimension, and the second partition when in position with a planar component provides apertures having a second dimension, such that the first and second aperture dimensions, etc., are not equal. In the most preferred embodiment, multiple partitions are oriented relative to a planar component to create a series of apertures of varying dimension such that the aperture dimensions progressively decrease in the direction of an effluent flow.
Further objects, advantages and embodiments of the invention will become evident from the reading of the following detailed description of the invention wherein reference is made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective drawing of one embodiment of the present invention showing a multi-partition wall filter component.
FIG. 2 shows an exploded view of one embodiment of the present invention with two inclined plates with the multi-partition wall filter to be engaged therebetween.
FIG. 3 shows a perspective view of an assembled portion of the embodiment shown in FIG. 2 .
FIG. 4 shows a perspective, partially exposed view of one embodiment of the present invention comprising a filter housing, or case.
FIG. 5 shows a partially exposed view of the housing of FIG. 4 now comprising a plurality of inclined filter plates and a maintenance plate.
FIG. 6 shows a perspective view of one embodiment of the present invention showing a dual filter housing with a plurality of receiving zones.
FIG. 7 shows a perspective view of an embodiment of the present invention showing a dual housing with two filter cartridges in place.
FIG. 8 shows a side perspective view of the dual housing embodiment of FIG. 7 , showing the maintenance plate impeding flow to the reserve filter cartridge.
DETAILED DESCRIPTION
According to one embodiment of the present invention, and with specific reference to the Figures, as shown in FIG. 5 , a new and improved effluent filter 10 is shown for uses, such as, for example, in septic systems. The filter 10 preferably comprises a housing, or case 12 surrounding at least two, and typically a plurality of inclined settling plates 14 separated by a multi-partition wall assembly 16 (See FIG. 1 ).
Referring now specifically to FIGS. 1 and 2 , according to one embodiment of the invention, the multi-partition wall assembly 16 of one embodiment of the present invention is shown. The assembly consists of at least one filtering wall(s) or dams 66 connected by at least one spacing support 64 . The top 63 and bottom 65 edges of the multi-partition wall 66 comprises a plurality of connecting pins 78 with male end 80 .
As shown in FIG. 2 , according to one embodiment of the present invention, the inclined settling plates 14 comprise a plurality of female receiving locations 82 designed and dimensioned to receive the male ends 80 of the multi-partition wall assembly 16 (See FIG. 1 ), thus forming one assembled portion 18 (See FIG. 3 ) of an embodiment of the present invention. The present invention further contemplates having fastening and spacing elements such, as, for example, the connecting pins 78 with the male end 80 as an integral part of the settling plate with the female receiving location being oriented as an integral part of the partition wall, or any combination thereof, as desired.
In one embodiment of the present invention, as shown in FIGS. 2 and 3 , the connecting pins 78 also play an important structural role in the filtering action of the filter unit 10 . The dimension (e.g. height) of each connecting pin 78 assists in determining the distance between each multi-partition wall 66 and the adjacent inclined settling plate 14 , thus creating apertures. The connecting pins 78 must provide a sufficient distance between each multi-partition wall 66 and the adjacent inclined settling plate 14 , such that a series of gaps, or apertures 122 , 124 and 126 are formed between at least the edge 65 of the filtering walls or dams 66 and the first or second surfaces 60 of an adjacent inclined settling plate 14 . Similarly, apertures 121 , 123 and 125 are formed between at least the edge 65 of the filtering walls or dams 66 and the underside of an adjacent inclined settling plate 14
As shown in FIG. 3 , the dimension of each gap, or apertures 122 , 124 and 126 in the series of apertures changes, and preferably becomes progressively smaller, such that the level of filtration becomes greater as liquid passes through. The dimensions of each connecting pin 78 , therefore, also becomes smaller as liquid moves through each subsequent gap created above or below each partition wall. This produces a progressively smaller or “thinning” aperture dimension, such that wide substances such as, for example, toilet paper, etc. become trapped within the filter, while liquid is allowed to pass through. Additional apertures, or filter slots 128 may be added as desired into the partition wall 66 on the inlet side, as well as the outlet wall. These slots 128 would be substantially the same size (opening) as apertures 122 and 126 respectively, or could be differently sized. Preferably, at least one, substantially circular rod channel 76 is positioned on diametrically opposing sides of each inclined settling plate 14 for receiving rods of a positioning unit, such as, for example, a handle. An additional opening 102 is provided in each settling plate. The openings 102 in each settling plate are aligned. One purpose for such an opening 102 is to receive an optional alarm system (not shown, but known in the field), within the filter unit 18 . One such alarm system that can be incorporated into embodiments of the present invention is provided in U.S. Pat. No. 6,841,066, which is incorporated by reference as if made a part of the present specification.
FIG. 4 shows an embodiment of the present invention, where the filter housing, or case 12 comprises a first section 30 that holds the filter assembly 18 . The base of the case 12 shows that the first section 30 comprises an inclined lower shelf 32 upon which rests the filter cartridges 18 , along with a receptacle 34 into which the assembly rod seats, to assist in retaining the cartridges in place, as desired. The interior walls of the case 12 have a series of receiving members, or tracks 36 forming a channel 38 into which a maintenance plate 40 (See FIG. 5 ) is inserted and “slid” into place, in order to block the flow of liquid from the second (unfiltered) section 42 of the case 12 to the section 30 . This allows the filter cartridge 18 to be removed and cleaned, serviced or replaced without allowing unfiltered liquids to exit the septic tank. FIG. 5 shows the filter cartridges 18 in place in the case 12 with the maintenance plate 40 also in place. Not shown is a rod, upon which the sections of settling plates stack. The rod is then preferably capped at both ends, securing the plates tightly together.
FIG. 6 shows another embodiment of the present invention, where the filter case 12 comprises dual filter receiving zones 30 and an unfiltered flow channel 42 near the center of the case 12 . FIG. 7 shows this case with two filter cartridges in place.
FIGS. 7 and 8 further show the dual filter case 31 , having two filter cartridges 18 in place. The maintenance plate 41 is in place, keeping a reserve cartridge from becoming soiled until needed to replace the cartridge 18 in the first filter zone.
The present invention, therefore, contemplates an improved filtration system having at least one partial partition wall placed substantially perpendicular to, and between, adjacent planar walls to form at least two filter apertures. Filter apertures are created between an area at the top edge of the weir wall and the bottom planar surface of one inclined plate. The second aperture is preferably created at an area between the bottom edge of the weir wall and the top planar surface of the adjoining inclined settling plate. The system preferably comprises substantially smooth surfaces that are preferably inclined at an angle of less than 90° relative to the planar floor 13 of the housing 12 , as shown by angle in FIG. 4 . However, the surfaces may be textured, if desired. As stated above, two or more partition walls may be present. In one embodiment, the aperture area of each progressive wall changes or remains constant, but preferably becomes smaller in size.
Embodiments of the present invention further comprise a mounting means for mounting a high level alert device, or alarm system, preferably located in a filtered waste water side of the filter device. The mounting means may be integral with the filter device. Further, filter elements preferably have a closed bottom mounted in the filter housing and comprise a means for installing a maintenance plate to block the flow out of the tank during filter cleaning, maintenance or replacement. The inclined shelf or shelving on the bottom of the filter housing preferably has a receptacle to allow a handle, such as, for example, a rod to engage the unit and preferably lock into place. In addition, a receptacle is preferably located in the back of the filter housing for storing at least one maintenance plate and optionally a spare filter cartridge.
A central flow channel in the system is designed to encourage a well-developed laminar flow regime to optimize separation of solids and to maximize retention time within the filter system. By facilitating and/or creating a large flow area within the case itself prior to liquid entering the filter, the velocity of the flow is reduced thus allowing the opportunity for solids to settle back into the septic tank for further treatment. This too increases the service life of the filter.
While the apertures of varying dimension are shown in the FIGs. as occurring at the “top” and “bottom” of the partitions, it is contemplated herein that the apertures may occur on the sides of the partition also, to enhance filtering performance as desired, with or without the presence of connecting pins.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be construed in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims set forth below rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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The present invention is directed to a method for filtering fluid, preferably effluent fluid in a septic system, by providing a staged, filtering array in an effluent flow path, the stages positioned in an orientation designed to maximize filtering capability in conjunction with predetermined aperture positions and dimensions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application No. 61/727,643 also titled “Method and Devices to Convey Session Participant List to a Store and Forward Group Chat Recipient” filed by the present inventors on Nov. 16, 2012.
FEDERALLY SPONSORED RESEARCH
[0002] None.
SEQUENCE LISTING
[0003] None.
FIELD OF THE INVENTION
[0004] This pertains to telecommunications message servers, telecommunications messaging clients including mobile devices and wireless tablets, and provides a method to convey an accurate list of group chat recipients to those messaging clients which are temporarily unavailable.
BACKGROUND OF THE INVENTION
[0005] Currently the telecommunications standards such as Rich Communication Suite including RCS-e and RCS-5.x and other standards define Store and Forward messaging for recipients of 1-to-1 chat sessions. RCS 5.1 further provides a store and forward notification method for group recipients which are powered off or otherwise not available during the chat session. However, as defined by current industry standards the store and forward solution is not ideal for group chat as not all information about the group is given to the unavailable recipient when the recipient becomes available. Typically recipients in a session are notified as participants join or leave the session and messaging during the session does not contain an actual recipient list for the message, as everyone currently in the session receives the message. Group chat recipients which may be powered-off or otherwise unavailable at the time of the chat therefore as they do not know who was involved in the group and who else received the same message. The present inventors have solved this problem.
SUMMARY OF INVENTION
[0006] The described method and telecommunications message server and telecommunication clients provide an accurate list of group chat participants to a store and forward group chat messages in an ad-hoc or predefined group scenario with the complete list of group participants supplied with each message. Note that either the list of group participants at the beginning of the chat session, or the list of recipients for each message (accounting for members that may have left the group) may be sent to the store and forward group chat recipient.
GLOSSARY
[0000]
200 Ok Standard response after successful request
ACK Acknowledgement that the SIP handshake is complete and a session will be setup (the third step of SIP “three way handshake.”)
3GPP Third Generation Partnership Project
CPIM Common Presence and Instant Messaging as described in IETF RFC 3862
DIAMETER DIAMETER Base Protocol as described in IETF RFC 3588
IETF Internet Engineering Task Force
IMDN Instant Message Disposition Notification (e.g. a “read reply” or a display notification)
INVITE a SIP Message that indicates a client is being invited to participate in a session (the first step of SIP “three way handshake”)
MDN Mobile Device Number
Mobile A mobile device that supports the group chat client as modified for the current invention.
MSRP Message Session Relay Protocol
MSRP 200 OK MSRP successful acknowledgement message
SIP 200 Ok Standard response after successful SIP request (the second step of SIP “three way handshake.”)
PNR DIAMETER Protocol command “Push Notification Request”
RCS Rich Communication Suite
RCS-5 Rich Communication Suite version 5
RCS-e Rich Communication Suite version e, common in Europe.
RCS Store and Forward Server A particular Telecommunications Message Store and Forward Server
RFC Request for Comments document published by Internet Engineering Task Force
Sh Diameter protocol interface as described in 3GPP technical specifications 29.328 and 29.329.
SIP Session Initiation Protocol
S&F Store and Forward
X-CSCF Any of the I-CSCF (Interrogating—Call Session Control Function), P-CSCF (Proxy—Call Session Control Function) and S-CSCF (Serving—Call Session Control Function.
BRIEF DESCRIPTION OF DRAWINGS
[0030] FIG. 1 shows delivery of a group chat message to a recipient, Mobile 2 , that was unavailable at the time of the group chat session. Note that the other recipients of the group messages are sent to Mobile 2 as part of each message as seen in the MSRP SEND messages received from the Store and Forward server. It is possible for each message to have a slightly different list of group members as group members join or leave the chat session.
[0031] FIG. 2 shows a listing of a sample store and forward group message after it has been transformed by the telecommunications store and forward server. Note the lack of a group identifier in and the repeated use of the “To” header in the CPIM formatted message.
DETAILED DESCRIPTION
[0032] For private chat messages the CPIM ‘To’ and ‘From’ header will contain the recipient's address (such as a MDN) and sender's address (MDN) respectively. Under the current art, for group chat scenarios the CPIM ‘From’ header is still the sender's address, such as MDN, but the CPIM ‘To’ header only contains an indication of the group, such as the group session identity. Specifically for adhoc groups the CPIM ‘To’ header may contain the IM Session Identity or <Session ID>@<Server Domain>. For Predefined groups the CPIM ‘To’ header contains the predefined Group ID (or short code).
[0033] In addition, during a group chat session the active participants may change over time as participants join or leave the group chat session. Typically, the current session participants are conveyed to all available participants using the SIP SUBSCRIBE/SIP NOTIFY operations. So, each client subscribed and available, will typically receive a SIP NOTIFY message each time a participant joins or leaves the chat session. However, SIP SUBSCRIBE/SIP NOTIFY are not supported in the telecommunications standards during a store and forward chat session used to deliver stored messages to an unavailable recipient client. It would also be complicated to use this method, since, once the client becomes available, the server will deliver all stored messages very quickly and the actual state of participants leaving and joining the session may not necessarily be recorded by the store and forward client recipient device.
[0034] The new method transforms the stored messages into private messages by recording the actual recipient list for each message directly in one or more CPIM ‘To’ headers as the messages are stored. For stored group messages, a telecommunications message server such a RCS Store and Forward Server will record the connected session participant addresses in the CPIM ‘To’ header similar to the format used for private group chat messages. For adhoc groups the CPIM ‘To’ header containing a list of one or more individual recipients replaces the IM Session Identity or <Session ID>@<Server Domain> used in adhoc groups. For Predefined groups the list of individual recipients in ‘To’ headers replace the CPIM ‘To’ header containing the predefined Group ID (or short code).
[0035] This method can also be used when a SIP INVITE starting a group chat session contains message payload. In this case the individual recipient list derived from the inbound group message is recorded with the message payload when the message is stored on the server for later delivery to the client.
[0036] The rule for when message storage will occur on the telecommunications server can be configurable with the possible options:
[0037] Option 1: Store messages for all participants, when none of the recipients are available initially when the group chat session is initiated. In this case the session would proceed, with all participants other than the session initiator in store and forward mode.
[0038] Option 2: Store messages for unavailable participants when one or more recipients are available for the initiated group chat session. In this case available participant including the chat session initiator and available recipients are invited to the chat session. Additional unavailable recipients are added to the session in store and forward mode.
[0039] Option 3: When a chat session participant drops from the session for a connection failure or other unexpected issues, the Server will convert the recipient to store and forward, while attempting to reestablish the session connection also. The session connection should be attempted for the remaining duration of the session. The store and forward attempts to deliver the stored message will continue after the session has been terminated
[0040] Option 4: The individual subscribers could have provisioning options for store and forward recorded in the presence server or subscriber database that control when store and forward will trigger for the individual when not available.
[0041] When the original group chat session is still active the Server attempts to connect the store and forward subscriber to the original session. If the connection is made during the session, any stored messages are forwarded to the recipient in order using that session (with the private messaging addresses in the CPIM ‘To’ headers, and original submission time stamps). Then the added participant can initiate new messages in the session as normal.
[0042] After the original session has ended, the Store and Forward Server will attempt to connect a store and forward session to the recipient with the stored messages. In this case the recipient list in the SIP INVITE will contain only the store and forward participant as the only chat session participant. In addition if SIP SUBSCRIBE is received for the session, the SIP NOTIFY will only indicate either the final participant list of the session or, alternately, indicate that only the one recipient is connected to the session. All stored messages are sent to the participant using the store and forward session which is a special session used to deliver store and forward messages to the previously disconnected recipient. A new session must be initiated if any new messages need to be sent. The CPIM ‘From’ header as normal conveys the original senders' address and the CPIM ‘To’ headers in this case conveys all the original recipients for the messages using the private addressing format. The Date and Timestamp of the message at submission to the server are conveyed as normal. The SIP INVITE used to setup the store and forward session can contain an optional text message in the SIP Subject header that indicates it is a stored session with a date and time stamp, and the initial list of participants. This text message provides basic information to the recipient allowing the recipient to determine if the session is of interest.
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This invention provides a telecommunications server apparatus and related wireless messaging client apparatus to transmit a group message with an accurate group recipient list to store and forward group message recipients.
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[0001] The invention relates to insulation systems for sub-sea hydrocarbon flowlines, and in particular to systems for controlling the overall heat transfer coefficient (OHTC) of conduits insulated by pipe-in-pipe construction.
[0002] Insulated flowlines are commonly used to maintain flow in warm hydrocarbon fluids produced from sub-sea wells. Without insulation, the fluids would cool rapidly to sea temperature and normally would solidify in the flowlines, with disastrous results. A particular type of insulation is the “pipe-in-pipe” or double walled structure.
[0003] The pipe-in-pipe flowline may be arranged horizontally on the seabed, but the invention will be described particularly in the context of a riser or riser tower of the type described in U.S. Pat. No. 6,082,391 [Stolt-Doris], or in our co-pending international application WO 02/53869A [63752WO], not published at the present priority date. The pipe-in-pipe flowline may be formed generally as described in French Patent FR 2746891 (assigned to ITP) and other patents of ITP. The pipe-in-pipe flowline may be formed using special bulkhead units, as described in application PCT/EP 03/04178 [64054WO], also not published at the present priority date. The pipe-in-pipe flowline may incorporate active heating, as described in application U.S. Prov 60/385243 [63981US] filed on the present priority date. The contents of all these applications are incorporated herein by reference.
[0004] It may be desirable under particular circumstances to control the Overall Heat Transfer Coefficient (OHTC) of a Pipe-in-Pipe system. This may be due to the fact that, during a pan of the field life, the well stream temperature may be higher.
[0005] In this case it is interesting to modify the OHTC by acting on the pressure of the gas contained in the annulus of the Pipe-in-Pipe. ITP have proposed de-pressurising the annulus of a Pipe-in-Pipe from atmospheric pressure to partial vacuum (about 10 mbar) in order to reduce the conductivity of a microporous material from (for example) 0.02 W/m 2 .K to 0.007 W/m 2 .K.
[0006] When applied to an Hybrid Riser Tower, the ITP proposed system would require to pull a vacuum from the buoyancy t located at about 50 m below sea-level. Even-though this scheme is, in theory, feasible, it is elaborate, and susceptible to catastrophic failure leading to the loss of the insulation of the riser, should water find its way into the annulus.
[0007] Gases, below their critical temperature, have, for a given temperature, a significantly larger conductivity when maintained above their critical pressure, than below. This phenomenon is described, for example, in Eckert, E. R. G., “Analysis of Heat and Mass Transfer“, McGraw-Hill, 1972, p. 770. See in particular FIG. B-6: The thermal conductivity k of water and water vapour as a unction of pressure and temperature. Referring also to Reid et al, “Properties of Gases and Liquids”, McGraw-Hill, 1987, this states on p. 518 “Increasing pressure raises the thermal conductivity, with the region around the critical pressure being particularly sensitive”. On p. 519 there is FIG. 10-5: Thermal conductivity of propane, and it is stated that the curves shown are similar in form to those of water vapour, for example. The latter book also includes a table of relevant data for several hundred gases.
[0008] The invention provides a method of controlling the heat transfer properties of a sub-sea conduit having inner and outer walls and a gas-permeable space between the walls providing thermal insulation, the method comprising varying the pressure of gas within the space between values above and below a critical pressure range at which thermal conductivity of the gas exhibits a high rate of change.
[0009] The proposed method is to pressurise the annulus above the critical pressure, and then to release the pressure to achieve a lower conductivity. The control thus achieved is a step change between two values of conductivity. the pressure change can be made in the reverse direction, and repeated if necessary for the application.
[0010] The conduit may form part of a riser for carrying flowlines from the seabed to a surface installation. The conduit may terminate at a submerged buoyant support, as in a hybrid tower riser. A port for passage of said gas may be provided at the location of the submerged buoyant support. One or more valves may be used for controlling the flow of said gas from the space.
[0011] In a preferred embodiment the pressure within the space remains equal to or greater than the ambient pressure at the port.
[0012] The valve may be adapted for operation by remotely operated vehicle (ROV), for example.
[0013] A gas inlet connection may be provided for use in increasing the gas pressure. One-way check valves may be provided for preventing unintentional ingress of seawater in the event of pressure loss.
[0014] One proposed system is to start from a pressure which is higher than the critical pressure. For many gases such as carbon dioxide or nitrogen, the critical pressure is between 30 and 50 bars. This pressure is higher that the seawater pressure at the access point at the top of the Hybrid Riser Tower.
[0015] The invention further provides a fabricated pipe-in-pipe flowline adapted for use in the method according to the invention as set forth above.
[0016] The invention fiber provides a flowline installation including a submerged pipe-in-pipe flowline having an insulating space filled with gas at a pressure above its critical pressure, and further comprising at least one port for the release of said gas to a pressure below said critical pressure.
[0017] Further features and advantages of the invention will be apparent from the following description of examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which:
[0019] FIG. 1 illustrates schematically a deepwater installation including a floating production and storage vessel and rigid pipeline riser bundles in a deepwater oil field;
[0020] FIG. 2 is a cross-sectional view of a riser bundle suitable for use in the installation of FIG. 1 ;
[0021] FIG. 3 is a partial longitudinal cross-section of an insulated pipe-in-pipe flowline in the riser bundle of FIG. 1 ;
[0022] FIG. 4 is a longitudinal cross-section of a pipe-in-pipe flowline according to an alternative construction based on pre-fabricated bulkhead assemblies in the manner of PCT/EP 03/04178 [64054WO], mentioned above;
[0023] FIG. 5 shows schematically the arrangement of as ports for regulating the pressure in the annulus of the pipe-in-pipe flowline;
[0024] FIG. 6 shows in cut-away detail the port arrangement at the bead of the riser tower
[0025] FIG. 7 illustrates a modification of the tower of any of the above examples, in which the foam blocks extend only over parts of the tower's length.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] Referring to FIG. 1 , the person skilled in the art will recognise a cut-away view of a seabed installation comprising a number of well heads, manifolds and other pipeline equipment 100 to 108 . These are located in an oil field on the seabed 110 .
[0027] Vertical riser towers constructed according to the present invention are provided at 112 and 114 , for conveying production fluids to the surface, and for conveying lifting gas, injection water and treatment chemicals such as methanol from the surface to the seabed. The foot of each riser, 112 , 114 , is connected to a number of well heads/injection sites 100 to 108 by horizontal pipelines 116 etc.
[0028] Further pipelines 118 , 120 may link to other well sites at a remote part of the seabed. At the sea surface 122 , the top of each riser tower is supported by a buoy 124 , 126 . These towers arm pre-fabricated at shore facilities, towed to their operating location and then installed to the seabed with anchors at the bottom and buoyancy at the top.
[0029] A floating production and Storage vessel (FPSO) 128 is moored by means not shown, or otherwise held in place at the surface. FPSO 128 provides production facilities, storage and accommodation for the wells 100 to 108 . FPSO 128 is connected to the risers by flexible flow lines 132 etc., for the transfer of fluids between the FPSO and the seabed, via risers 112 and 114 .
[0030] As mentioned above, individual pipelines may be required not only for hydrocarbons produced from the seabed wells, but also for various auxiliary fluids, which assist in the production and/or maintenance of the seabed installation. For the sake of convenience, a number of pipelines carrying either the same or a number of different types of fluid are grouped in “bundles”, and the risers 112 , and 114 in this embodiment comprise bundles of conduits for production fluids, lifting gas, injection water, and treatment chemicals, methanol.
[0031] As is well known, efficient thermal insulation is required around the horizontal and vertical flowlines, to prevent the hot production fluids overly cooling, thickening and even solidifying before they are recovered to the surface. It is also the case that the insulation properties the flowlines and the bundle must be specifically designed to suit the temperature, pressure and chemical composition of the fluids being conveyed, which vary from field to field. In some cases, the temperature may vary widely between reservoirs in the same field, such that a single set of insulation parameters cannot be designed that will suit all the desired operating conditions. Where a fluid is very hot, some hot loss is positively required, to avoid damage, danger, and/or handling difficulties when the fluid reaches the flexible jumpers and the surface vessel.
[0032] FIG. 2 shows in cross-section one of the riser towers 112 or 114 . The central metallic core pipe is designated C, and is empty, being provided for structural purposes only. If sealed and filled with air, it also provides buoyancy. Arrayed around the core are production flowlines P, gas lift lines G, water injection lines W and umbilicals U.
[0033] The various lines P, G, W, and U are held in a fixed arrangement about the core. In the illustrated example, the lines are spaced and insulated from one another by shaped blocks F of syntactic foam or the like, which also provides buoyancy to the structure.
[0034] Flowlines P and gas lift lines G in this example are housed within insulation 1 . This may be a solid coating of polypropylene (PP) or the like, but in at least one of the flowlines, a “pipe-in-pipe” insulation has been adopted, to give high insulation, and moreover controllable insulation, in the manner described in the introduction. As described in our co-pending international application WO 02/53869A [63752WO], additional insulation may be provided, the flowlines may be located within a core pipe, and other variations are possible, which will not be detailed herein.
[0035] Of course the specific combinations and types of conduit are presented by way of example only, and the actual provisions will be determined by the operational requirements of each installation The skilled reader will readily appreciate how the design of the installation at top and bottom of the riser tower can be adapted from the prior art including U.S. Pat. No. 6,082,391, mentioned above, and these are not discussed in further detail herein, except where they are modified to control the annular gas pressure, as further described below. Monitoring of the central temperature and pressure can be easily provided by embedding a Bragg effect optic fibre.
[0036] As will be appreciated by those skilled in the an the functional specification of the tower will generally require one or two sets of lines, and may typically include within each set of lines twin production flowlines to allow pigging and an injection line. A single water injection line may be sufficient, or more than one may be provide.
[0037] FIG. 3 of the drawings shows in more detail a first alternative construction of the “pipe in pipe” insulated flowline suitable for use within the riser described above as well as in other similar types of applications, this construction for the flowline can be described as arrangement, known per se in the art. This arrangement is generally provided in prefabricated sections 700 for fitting, for example welding, together and FIG. 7 shows in longitudinal cross-section the joint between two such sections, which naturally extend to left and right of the picture.
[0038] Each section comprises a central pipe 701 for the transport of fluids such as production fluids and a second pipe 702 in which the pipe 701 is housed for the major part of its length. Ends 703 of the pipe 701 extend beyond the second pipe 702 and enable the sections 700 of the pipe 701 to be secured together in end to end relationship so as to form a pipeline. The second pipe 702 is bent down at its ends 704 to be welded to the outside of the pipe 701 near to the ends 703 and so defines a space 705 between the two pipes. This space 705 provides and or houses the insulation for the pipeline.
[0039] In one embodiment a layer 706 of an insulating material, may be provided over the outer surface of the pipe 701 within the space 705 . The insulating material may be a microporous material, for example ISOFLEX (a Trade Mark of Microtherm) which is a ceramic like material. With this type of arrangement a gap will still be present between the layer 706 and the inner surface of the pipe 702 .
[0040] In order to protect and insulate the area around the join in the flowline, it is encased and fixed within a joint 700 . The joint 700 comprises a sleeve 711 having an outer surrounding sleeve 712 which as with the section defines a space 714 in which insulating material is located, for example a layer 714 of ISOFLEX as shown in FIG. 7 , or polyurethane foam, and two heat shrink end collars 710 . The sleeve arrangement 711 , 712 and the heat shrink collars 710 are located about one of the sections prior to welding of two sections. When welding is complete the component are slid into place about the join in the pipe. An epoxy resin material is injected into the space 707 defined between the sleeve arrangement and the flowline to fill that space. The beat shrink collars 710 are then heated so that they shrink and seal the sleeve arrangement to the flowline.
[0041] The spaces 705 and 707 would conventionally be filled with air or other gas. The pressure in this space would be normal atmospheric, or a partial vacuum may be created so as to reduce convective beat losses. In the present example, however the pressure of the gas is maintained above ambient sea pressure at all times, and is varied either side of the critical pressure” at which the thermal conductivity k of the gas varies markedly. Ports (not shown) are provided through the joints, to allow control of the gas pressure in the space 205 throughout the structure, and so to control the heat transfer coefficient OHTC of the flowline according to prevailing operation conditions.
[0042] FIG. 4 shows the upper end of a second alternative construction of pipe-in-pipe flowline, which includes a main flowline 776 and an auxiliary pipe 774 within outer casing 770 . As described in our co-pending application PCT/EP 03/04178 [64054WO], mentioned above, this structure can be assembled from pipe initiation segments on either side of the a special bulkhead 780 . After applying initiation segments to the bulkhead units, a long insulated flowline can be welded from sections by conventional orbital welding, unlike the more conventional pipe-in-pipe structure of FIG. 3 . Gas communication between segments of the annular space is provided by ports (not shown), formed in the bulkhead 780 .
[0043] The auxiliary pipe 774 may be a gas lift line, for example, or may convey sensors. Alternatively, or in addition, the pipe-in-pipe flowline may carry water for supplementary heating of the flowline, as described in application U.S. Prov 60/385243 [63981US] mentioned above.
[0044] FIG. 5 shows schematically the fluid (gas) connections around the upper end of the pipe-in-pipe riser flowline in an ROV-operated example. Diver operation or full remote control is also possible. This end of the pipe is located conveniently at the buoyancy tank ( 124 , FIG. 1 ), a depth h beneath the sea surface 122 , although other locations are possible. The inner pipe is shown at 800 , while the outer pipe and end closures are shown at 802 , with the space referred to as “the annulus” shown at 804 . The space may contain foam, in addition to gas, as desired. A port 806 is provided which connects annulus 804 to an ROV pressure relief connection 808 . A pressure gauge connection 810 is provided for monitoring the gas pressure, with pressure gauge barrier valve operable by the ROV at 812 .
[0045] An annulus pressure control valve 814 is operable by the ROV to connect the annulus to allow gas to flow from the annulus to the outside via connection 808 . A check valve 816 is included to prevent ingress of water to the annulus. Valve 814 may be of double block type. Check valve 816 may have an override facility for pressurising the annulus with gas.
[0046] FIG. 6 shows in greater detail one possible structure for the top end connection and annulus access ports inner and outer pipes 800 , 802 are welded at 801 and 803 respectively to a specialty formed termination unit 820 , supported on the buoyancy tank top structure. Production fluid connection is made to the main flange surface 822 , while annulus access ports 806 are connected through bores in the termination unit 820 as shown. The area shown generally as 824 is thermally protected by a “dog house” structure after connection of the “gooseneck” and flexible jumper. These parts are conventional, and omitted for clarity.
[0047] In operation, the annulus is initially filled with pressurised gas. The initial pressure is above the critical pressure, giving a relatively high initial OHTC. This allows the production of fluid from a well having a particularly high temperature which, without substantial beat transfer to the ambient seawater, would cause problems at the surface. At a late date, when production fluids are of a lower temperature or otherwise different in character, the OHTC can be adjusted to decrease thermal transfer can be done merely by releasing the gas under its own pressure by Operation of the valve 814 .
[0048] The pressure can be maintained at all times above the surrounding seawater pressure, avoiding seawater ingress detrimental to insulating material properties Gas can be suitably selected to meet project specific requirements. Happily, calculations show that cheap and relatively inert gases such as Carbon Dioxide and Nitrogen are likely to be suitable for the range of temperatures and pressures experienced by deepwater hybrid riser tower bundles. Of course, a mixture of gases can be used for further control or convenience.
[0049] The process can be made reversible, if in the later stages of the field it is necessary to revert to the previous OHTC. With suitable conduits, couplings and compressors, the Pipe-in-Pipe annulus may be again pressurised while in place. For the period when a higher OHTC is required the pressure can be set above the critical pressure. When the lower OHTC is required the pressure can be released to a pressure close to the seawater pressure (about 6 to 8 bar), which is well below the critical pressure of both gases.
[0050] FIG. 7 illustrates a stepped tower construction, compatible with any of the examples of FIGS. 2 to 6 . Thanks to the insulation on the flowlines themselves, the foam blocks F need not extend the full length of the tower. In this example the foam buoyancy material is provided in discrete sections spaced apart along the length of the riser tower. Advantages of the stepped tower include reduced cost, and controllable buoyancy. Another advantage of varying the cross-section along the length of the tower is a reduced tendency to vortex-induced vibration, under the influence of water currents. In embodiments where some of the warmer lines are outside the core, individual or group insulation of the lines is of course necessary, at least in the sections between the foam blocks, as in the co-pending application mentioned above.
[0051] The skilled person will recognise that the above examples are intended for illustration only, and many variations are possible without departing from the spirit and scope of the invention.
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A method of controlling the heat transfer properties of a sub-sea conduit having inner and outer walls ( 800, 802 ) and a gas-permeable space ( 804 ) between the walls providing thermal insulation, the method comprising varying the pressure of a gas within the space between values above and below a critical pressure range at which thermal conductivity of the gas exhibits a high rate of change.
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GOVERNMENT RIGHTS
The United States Government has acquired certain rights in this invention pursuant to Contract No. DTRA01-03-D-0018 and Delivery No. DTRA01-03-D-0018-0001 awarded by the Defense Threat Reduction Agency.
FIELD
The present invention relates generally to the field of integrated circuit charge pumps and more particularly to a differential charge pump with active and common mode regulators.
BACKGROUND
As Integrated Circuits (ICs) continue to become more advanced, the transistors that are used to construct them continue to decrease in size. Decreases in transistor size create changes in operating specifications associated with smaller transistors. Such changes include decreased operating voltages and tighter common mode voltage tolerances.
One type of device that is affected by decreased operating voltage and tighter common mode voltage tolerances is a charge pump. Charge pumps are fundamental components of many types of devices. For example, a charge pump may be used to adjust the amount of voltage applied to a low pass filter in a phase locked loop. One such charge pump (a differential charge pump) is illustrated in FIG. 1 . Charge pump 10 includes a current steerer 12 which is coupled to receive a source current from a current source 14 and a sink current from a current sink 16 . The current steerer distributes the source and sink current to output terminals NEG 18 and POS 20 . Signals applied to a differential control (differential input terminals 22 A-D) may be used to determine a duty cycle associated with the amount of time the source and sink currents are steered to a respective output terminal.
The output terminals 18 and 20 may each be coupled to a capacitor that uses the source and sink currents to charge and discharge. By changing the duty cycle, via the differential inputs 22 A-D, the amount of voltage stored on a particular capacitor may be adjusted. For example, if the capacitors are used in a loop filter (in a phase locked loop), the voltage level on each capacitor may be used to differentially control the output frequency of a voltage controlled oscillator.
Because the current steerer 12 is comprised of Field Effect Transistors (FETs) 24 - 27 , decreasing operating voltages (which may be associated with decreasing transistor sizes) have a direct impact on the output current range of current steerer 12 . This becomes apparent by examining nodes 28 and 30 . The maximum voltage at node 28 and the maximum voltage at node 30 limit the maximum range of output voltage available for input voltages at FETs 24 - 27 . For example, as operating voltages decrease, a larger percentage of an operating voltage intended for FETs 24 - 27 may be distributed across current source 14 and current sink 16 . When this happens less voltage is available for nodes 28 and 30 , and as a result, the output current range of current steerer 12 is reduced.
Another shortcoming with current charge pumps is common mode voltage drift. Common mode voltage drift occur when small asymmetries in the charge pump 12 (or asymmetries in the circuit referencing the charge pump) may cause the positive or negative DC voltage across output terminals 18 and 20 to drift to an undesirable voltage level. For example, due to statistical variations that occur in manufacturing (i.e., semiconductor processing), FET 24 may have a smaller channel length (ΔL), channel width (ΔW), and/or threshold voltage (ΔV t ) than FET 25 . Over time, small differences in current resulting from an asymmetry may cause a capacitor referencing output terminal 20 to store a small increment of charge at each clock cycle. Another capacitor referencing output terminal 18 may not store this increment of charge. A DC voltage, therefore, is established between output terminals and it may grow, or drift, with each clock cycle.
Current charge pumps employ a feedback mechanism that monitors the DC, or common mode, voltage. By monitoring the common mode voltage through a feedback path, and adjusting the charge pump based on the feedback, a feedback mechanism may compensate for the asymmetry. This may be done by adjusting the duty cycle applied to the current steerer 12 , for example. Unfortunately, the feedback mechanism increases the complexity of the charge pump and produce additional overhead. The problems associated with asymmetry may also be further exacerbated with decreased transistor sizes.
Therefore there is a need for a charge pump that has an output range that is not restricted by device scaling and processing asymmetries.
SUMMARY
A differential charge pump with open loop common mode is presented. The differential charge pump includes a current steerer that uses a differential control to steer source and sink currents to differential output terminals. In one example, the output terminals are coupled with a common mode regulator which drives a common mode voltage of the differential charge pump. The common mode regulator operates independent from external circuitry and does not require feedback (open loop).
In a further example, the common mode regulator includes a voltage driver coupled with a pair of resistances. The voltage driver may be an inverter having an input coupled to an output in order to establish a voltage that is about half of a power supply voltage. The output of the inverter is coupled with the resistances. A resistance value associated with the resistances may be tailored to prevent a substantial portion of the source and sink currents from entering the common mode regulator.
In another example, the current steerer is coupled with an active regulator. The active regulator reduces overhead voltage associated with a current source which is used to generate the source current. The operating range of the current steerer is thereby increased. In a further example, a second active regulator may be used to reduce overhead associated with sink current generation.
In yet another example, the differential charge pump may employ both an active regulator and a common mode regulator in order to increase operating range and create a desired common mode voltage. These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it is understood that this summary is merely an example and is not intended to limit the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain examples are described below in conjunction with the appended drawing figures, wherein like reference numerals refer to like elements in the various figures, and wherein:
FIG. 1 is a circuit diagram of a differential charge pump;
FIG. 2A is a circuit diagram of a common mode regulator;
FIG. 2B is a circuit diagram of another common mode regulator;
FIG. 3A is a circuit diagram of an active regulator;
FIG. 3B is a circuit diagram of another active regulator; and
FIG. 4 is a circuit diagram of a differential charge pump including a common mode regulator and two active regulators.
DETAILED DESCRIPTION
A differential charge pump including a common mode regulator and/or an active regulator is presented. The common mode regulator and the active regulator are coupled with a current steerer. The common mode regulator establishes, without a feedback path, the common mode voltage level of the charge pump. In doing so, an erroneous voltage build up which may be associated with asymmetries inherent to the charge pump may be mitigated. The active regulator, on the other hand, increases the amount of input voltage that is distributed to the charge pump. As a result, the output range of the charge pump is also increased.
Turning now to FIG. 2A , an example common mode regulator 32 is illustrated. The common mode regulator includes a voltage driver 34 and resistances 36 and 38 . Common mode regulator 32 includes a FET 40 , which may be used to turn the common mode regulator on and off. FET 40 may be excluded from the implementation of other common mode regulators, particularly in common mode regulators that are always on.
The output terminals 42 and 44 are respectively coupled to output terminals 18 and 20 of current steerer 12 . The resistances 36 and 38 should each have a resistance value that is high enough to prevent a substantial current from traveling through resistance 36 or 38 . Depending on the design of the common mode regulator 32 , resistances 36 and 38 may have a value such that only a minimal portion of output current (e.g. less than 1%) travels through these resistances. Resistances 36 and 38 may each be a resistor, such as a doped silicon or polysilicon resistor formed in a Complimentary Metal Oxide Semiconductor (CMOS) process, for example.
In order to establish a common mode voltage in a differential charge pump, voltage driver 34 is coupled to node 46 which joins resistance 36 and 38 . Voltage driver 34 determines the common mode voltage that is output at output terminals 18 and 20 of the current steerer 12 . Voltage driver 34 may be set to a variety of voltages. For example, the common mode voltage may be determined by the technology node (i.e., 5V, 3V, or 1.6V) or an application that a particular differential charge pump is directed to.
Common mode regulator 32 prevents deviation in common mode voltage, and in particular common mode voltage drift, in current steerer 12 by driving the voltages at the output terminals 18 and 20 to the voltage level of the voltage driver 34 . Without common mode regulator 32 (and voltage driver 34 ), deviations in common mode voltage may cause the dynamic range of current steerer 12 to decrease. In addition, other deleterious effects may occur. One effect may be any of the FETS 24 - 27 becoming pinned at a supply or common voltage, thereby further reducing or eliminating the output range.
Common mode regulator 32 , however, prevents unwanted charge build up at terminal 18 or 20 , or a voltage from developing across these terminals, by sinking extraneous charge. The common mode regulator 32 may include a ground terminal or common terminal for this purpose. Additionally, because the voltage driver 34 operates independently from the current steerer 12 , extraneous charge will not cause its voltage level to drift over time and, as a result, the common mode regulator 32 is coupled with the current steerer 12 in an open loop.
The voltage driver 34 may be designed in a variety of ways. One such voltage driver 48 is illustrated in FIG. 2 b . Voltage driver 48 includes an inverter 50 having its output coupled in negative feedback to its input. A resistance 52 is also used to couple the input of the inverter to its output. Capacitances 54 and 56 are also included in the voltage driver 48 .
The negative feedback configuration of inverter 50 sets the voltage at node 58 to the switching threshold of the inverter 50 . For example, if the switching threshold is at 1.5V the voltage at node 58 will be 1.5V and therefore the common mode voltage of the current steerer will also be set to 1.5V. The switching threshold is determined by the design of inverter 50 and, depending on the application, may be adjustable.
Resistance 52 and capacitances 54 and 56 may be used to reduce noise, or glitching, in the switching of FETs 22 A-D located in current steerer 12 . Resistance 52 and capacitances 54 and 56 may be tailored to a specific current steerer or excluded. Other types of tailoring, such as selecting a mid-rail voltage, may be used to maximize the range of output terminals 18 and 20 of current steerer 12 .
Another way to maximize the range of output terminals 18 and 20 is to implement an active regulator. The active regulator maximizes the voltage that is applied to nodes 28 and/or 30 . As mentioned above, if a voltage applied to either one of these nodes is distributed across other circuit components subsequent to it being applied to node 28 and/or node 30 , the output range of output terminals 18 and 20 will be reduced.
FIG. 3A illustrates an example active regulator 60 . Active regulator 60 includes a current mirror (formed by FETs 62 and 64 ) and an amplifier 66 . The current mirror mirrors current from current source 14 to output terminal 68 . Amplifier 66 has its inputs coupled to the drains of FETs 62 and 64 . An output of amplifier 66 is coupled to the gates of FETs 62 and 64 . Amplifier 66 may be an operational amplifier, for example.
The output of amplifier 66 supplies a voltage that allows both FETs 62 and 64 to turn “on”. The supply voltage, V P , is pulled to the output terminal 68 and to both input terminals of amplifier 66 . The voltages between the drains of FETs 62 and 64 (amplifier 66 's input terminals) cannot deviate significantly from each other without increasing the current through FETs 62 and 64 . Therefore, the drains of FETs 62 and 64 will both maintain a voltage that is about equal to the supply voltage. In addition, the current mirror will mirror the source current to output terminal 68 . As a result, the active regulator 66 allows the source current to be supplied to output terminal 68 without reducing the voltage level at output terminal 68 . Output terminal 68 may be coupled to node 28 of the current steerer 12 to provide the source current and supply voltage.
A second supply, or common supply, voltage can also be coupled with a second active regulator that is coupled to the current steerer 12 . Example active regulator 70 is illustrated in FIG. 3B . Active regulator 70 also includes a current mirror (FETs 72 and 74 ) coupled to an amplifier 76 . Output terminal 78 is coupled to one input terminal of amplifier 76 . The other input terminal of amplifier 76 is coupled to current sink 16 . The output terminal 78 provides both the sink current and the common supply voltage V N to node 30 of the current steerer 12 . In the same manner as active regulator 60 , the common supply voltage supplied to output terminal 78 is optimized as it is directly distributed to current steerer 12 and does not have to be “dropped” across current sink 16 prior to being communicated to node 30 .
All of the above examples may be used in combination to create a differential charge pump. For example, FIG. 4 is a circuit diagram of differential charge pump 80 including common mode regulator 32 , active regulator 60 , and active regulator 70 all coupled to current steerer 12 . Differential charge pump 80 offers an improved operating voltage range and a common mode voltage that is determined without feedback.
Overall, the above examples describe a differential charge pump that offers an improved output range of lower operating voltages. As described above, these lower operating voltages may be associated with decreasing transistor sizes. The differential charge pump may include active and/or common mode voltage regulators. Although several example circuit structures have been shown, the present application should not be viewed as limited to these examples. A variety of structures and implementations may be realized that would be analogous and apparent to one skilled in the art. Additionally, the output of the differential charge pump may be a voltage or a current. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all examples that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.
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A differential charge pump with common mode and active regulators is presented. Either type of regulator may be used to improve the performance characteristics of the differential charge pump. The active regulator increases the output range of the differential amplifier. The common mode regulator establishes the common mode voltage of the differential charge pump. The common mode voltage is established independently from external circuitry and does not use a feedback path. The common mode regulator may also be used to establish a mid-rail voltage, which may be used to further improve the output range of the differential amplifier.
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This application is a divisional of application Ser. No. 08/248,564, filed May 24, 1994, now abandoned which is a continuation of application Serial No. 07/904,124, filed Jun. 25, 1992 and now abandoned, which is a divisional of application Ser. No. 07/546,235, filed Jun. 29, 1990 and now abandoned.
FIELD OF THE INVENTION
The invention relates generally to methods and compositions for treating diseases associated with immune system imbalances, particularly imbalances involving humoral and cell-mediated immune responses. The invention also includes proteins and antagonists thereof capable of modulating the synthesis of certain cytokines involved in immune system to achieve therapeutic effects.
BACKGROUND
Immune responses to antigen are classified as being predominantly either cell-mediated, exemplified by the phenomena of delayed-type hypersensitivity (DTH), or humoral, exemplified by the production of antibodies. Cell-mediated immunity is of paramount importance for the rejection of tumors and for recovery from many viral, bacterial, protozoan, and fungal infections. In contrast, a humoral immune response is the most effective form of immunity for eliminating toxins and invading organisms from circulation. It has been observed that for different antigens one or the other of these two responses often predominates in a mutually exclusive fashion, and that the severity of some diseases, e.g. leprosy, leishmaniasis, and some types of autoimmunity, may be due the inappropriate dominance of one class of response over the other, Mosmann et al, Immunol. Today, Vol 8, pgs. 223-227 (1987); Mosmann et al, Ann. Rev. Immunol., Vol. 7, pgs. 145-173 (1989); Parish, Transplant. Rev, Vol. 13, pgs. 35-66 (1972); and Liew, Immunol. Today, Vol. 10, pgs. 40-45 (1989). It has further been observed that sets of cytokines are separately associated with DTH reactions and humoral immune responses, Cher et al, J. Immunol., Vol. 138, pgs. 3688-3694 (1987); and Mosmann et al (1987 and 1989, cited above), and it is thought that diseases associated with these classes of response are caused by the inappropriate production of the associated sets of cytokines.
For example, a large body of evidence suggests that excessive production of gamma interferon (IFN-γ) is responsible for major histocompatibility complex (MHC) associated autoimmune diseases: Hooks et al, New England J. Med ., Vol. 301, pgs. 5-8 (1979) (elevated serum levels of IFN-γ correlated with autoimmunity); Basham et al, J. Immunol ., Vol. 130, pgs. 1492-1494 (1983) (IFN-γ can increase MHC gene product expression); Battazzo et al, Lancet , pgs. 1115-1119 (11/12/83) (aberrant MHC gene product expression correlated with some forms of autoimmunity); Hooks et al, Ann. N.Y. Acad, Sci ., Vol., pgs. 21-32 (1980) (higher IFN-γ levels correlated to greater severity of disease in SLE patients, and histamine-release enhancing activity of interferon can be inhibited by anti-interferon sera); and Iwatani et al, J. Clin. Endocrin. and Metabol ., Vol. 63, pgs. 695-708 (1986) (anti-IFN-γ monoclonal antibody eliminated the ability of leucoagglutinin-stimulated T cells to induce HLA-DR expression). It is hypothesized that excess IFN-γ causes the inappropriate expression of MHC gene products which, in turn, causes autoimmune reactions against the tissues whose cells are inappropriately expressing the MHC products and displaying autoantigens in the context of the products.
In the area of clinical parasitology, it has recently been observed that the levels of IFN-γ and IL-2 are important factors in the progression and/or resolution of the protozoan infection, leishmaniasis. In particular, the presence of adequate levels of IFN-γ appears to be essential for the activation of infected macrophages to eliminate intracellular amastigotes, Mauel and Behin, in Cohen et al, eds., Immunology of Parasitic Infections (Blackwell, London, 1982). And, in murine models of the disease, it has been shown that high levels of IFN-γ and low levels of IL-4 are associated with resolution, whereas low levels of IFN-γ and high levels of IL-4 are associated with progression of leishmaniasis, Heinzel et al, J. Exp. Med., Vol. 169, pgs. 59-72 (1989).
In view of the above, it would be advantageous to have available agents that could shift the dominance of one class of immune response to the other, and in particular that could suppress or increase the synthesis of IFN-γ and/or other cytokines, respectively, as required for therapy. Such agents would be highly advantageous for treatment of diseases associated with inappropriate or inadequate immune responses, such as tissue rejection, leishmaniasis and other parasitic diseases, and MHC associated immune disorders including rheumatoid arthritis, systemic lupus erythematosus (SLE), myasthenia gravis, insulin-dependent diabetes mellitus, thyroiditis, and the like.
SUMMARY OF THE INVENTION
The present invention is directed to mammalian cytokine synthesis inhibitory factor (CSIF), CSIF analogs, CSIF peptides, and CSIF antagonists. It includes nucleic acids coding for polypeptides exhibiting CSIF activity, as well as the polypeptides themselves, their agonistic and/or antagonistic analogs, methods for their production, and methods of using them to treat disorders associated with cytokine imbalances, particularly those leading to an inappropriate class of immune response. The invention also includes the use of CSIF or its antagonists, alone or as vaccine adjuvants, to selectively induce a predominantly cell-mediated immune response or a predominantly humoral immune response, respectively. Preferably, antagonists of CSIF are derived from monoclonal antibodies capable of blocking the biological activity of CSIF. The nucleic acids of the invention are defined (1) by their homology to, or their ability to form detectable hybrids with, the cloned complementary DNA (cDNA) sequences disclosed herein, and (2) by functional assays for CSIF activity applied to the polypeptides encoded by the nucleic acids. As used herein, the term “CSIF activity” in reference to a protein or a polypeptide means that the protein or polypeptide is capable of inhibiting or substantially reducing the level of production of at least one of the following cytokines in the assays described below: IFN-γ, interleukin-2 (IL-2), lymphotoxin, interleukin-3 (IL-3), or granulocyte-macrophage colony stimulating factor (GM-CSF).
A preferred embodiment of the invention is a mature human CSIF of the open reading frame defined by the following amino acid sequence:
MHSSALLCCLVLLTGVRASPGQGTQSENSCTHFPGNLPNM
LRDLRDAFSRVKTFFQMKDQLDNLLLKESLLEDFKGYLGC
QALSEMIQFYLEEVMPQAENQDPDIKAHVNSLGENLKTLR
LRLRRCHRFLPCENKSKAVEQVKNAFNKLQEKGIYKAMSE
FDIFINYIEAYMTMKIRN
wherein the standard one-letter symbols for L-amino acids are listed left to right starting from the N-terminal methionine. More preferably, the mature human CSIF is defined by the following amino acid sequence:
SPGQGTQSENSCTHFPGNLPNMLRDLRDAFSRVKTFFQMKDQLD
NLLLKESLLEDFKGYLGCQALSEMIQFYLEEVMPQAENQDPDIKA
HVNSLGENLKTLRLRLRRCHRFLPCENKSKAVEQVKNAFNKLQ
EKGIYKAMSEFDIFINYIEAYMTMKIRN
The invention is based in part on the discovery and cloning of cDNAs which are capable of expressing proteins having CSIF activity. Accordingly, several such clones designated pcD(SRα)-F115 (carrying a mouse CSIF gene), and pH5C and pH15C (each carrying a human CSIF gene) have been deposited with the American Type Culture Collection (ATCC), Rockville, Md. under the accession numbers 68027, 68191, and 68192, respectively.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a dose-response relationship for the degree of IFN-γ synthesis inhibition in several mouse T cell clones treated with different amounts of CSIF.
FIG. 2 is a diagram illustrating the major features of the mammalian expression vectors pH5C and pH15C.
FIG. 3 illustrates the RBS-ATG-polylinker region of plasmid TAC-RBS-hCSIF.
FIG. 4 illustrates the nucleotide sequence of the cDNA insert of pH15C.
DETAILED DESCRIPTION OF THE INVENTION
The invention includes mature polypeptides, or proteins, of the largest open reading frames of the cDNA inserts of pH5C, pH15C, pcD(SRα)-F115, and effectively homologous cDNAs, as well as antagonists thereof. For secreted proteins, an open reading frame usually encodes a polypeptide that consists of a mature or secreted product covalently linked at its N-terminus to a signal peptide. The signal peptide is cleaved prior to secretion of the mature, or active, polypeptide. The cleavage site can be predicted with a high degree of accuracy from empirical rules, e.g. von Heijne, Nucleic Acids Research, Vol. 14, pgs. 4683-4690 (1986), and the precise amino acid composition of the signal peptide does not appear to be critical to its function, e.g. Randall et al, Science, Vol. 243, pgs. 1156-1159 (1989); Kaiser et al, Science, Vol. 235, pgs. 312-317 (1987). Consequently, mature proteins are readily expressed by vectors encoding signal peptides quite different than that encoded by the open reading frame defined by the cDNA inserts of pH5C, pH15C, and pcD(SRα)-F115.
I. Obtaining and Expressing CSIF cDNAs
The term “effectively homologous” as used herein means that the nucleotide sequence is capable of being detected by a hybridization probe derived from a cDNA clone of the invention. The exact numerical measure of homology necessary to detect nucleic acids coding for CSIF activity depends on several factors including (1) the homology of the probe to non-CSIF coding sequences associated with the target nucleic acids, (2) the stringency of the hybridization conditions, (3) whether single stranded or double stranded probes are employed, (4) whether RNA or DNA probes are employed, (5) the measures taken to reduce nonspecific binding of the probe, (6) the nature of the method used to label the probe, (7) the fraction of guanidine and cytosine bases in the probe, (8) the distribution of mismatches between probe and target, (9) the size of the probe, and the like. Preferably, an effectively homologous nucleic acid sequence is at least ninety percent (90%) homologous to the cDNA of the invention. Most particularly, an effectively homologous nucleic acid sequence is one whose cDNA can be isolated by a probe constructed from a cDNA insert of pcD(SRα)-F115, pH5C, pH15C, or an equivalent thereof, using the hybridization protocol described in the examples with no more than a few false positive signals, e.g. less than a hundred. There is an extensive literature that provides guidance in selecting conditions for such hybridizations, e.g. Hames et al, Nucleic Acid Hybridization: A Practical Approach (IRL Press, Washington, D.C., 1985); Gray et al, Proc. Natl. Acad. Sci., Vol. 80, pgs. 5842-5846 (1983); Kafatos et al, Nucleic Acids Research, Vol. 7, pgs. 1541-1552 (1979); Sambrook et al, Molecular Cloning: A Laboratory Manual, 2nd Ed. (Cold Spring Harbor Laboratory, New York, 1989); and Beltz et al, Meth. in Enzymol., Vol. 100, pgs. 266-285 (1983), to name a few.
Homology as the term is used herein is a measure of similarity between two nucleotide (or amino acid) sequences. Homology is expressed as the fraction or percentage of matching bases (or amino acids) after two sequences (possibly of unequal length) have been aligned. The term alignment is used in the sense defined by Sankoff and Kruskal in chapter one of Time Warps, String Edits, and Macromolecules: The Theory and Practice of Sequence Comparison (Addison-Wesley, Reading, Mass., 1983). Roughly,two sequences are aligned by maximizing the number of matching bases (or amino acids) between the two sequences with the insertion of a minimal number of “blank” or “null” bases into either sequence to bring about the maximum overlap. Given two sequences, algorithms are available for computing their homology, e.g. Needleham and Wunsch, J. Mol. Biol., Vol. 48, pgs. 443-453 (1970); and Sankoff and Kruskal (cited above) pgs. 23-29. Also, commercial services and software packages are available for performing such comparisons, e.g. Intelligenetics, Inc. (Palo Alto, Calif.); and University of Wisconsin Genetics Computer Group (Madison, Wis.).
Restriction endonuclease fragments of the vectors carrying the cDNAs of the invention are used to construct probes (using standard techniques such as nick-translation, e.g. see Sambrook et al., cited above) for screening at low hybridization stringencies genomic or cDNA libraries (again, constructed by standard techniques) of a cell type suspected of producing CSIF. Standard screening procedures are employed, e.g. Grunstein et al., Proc. Natl. Acad. Sci., Vol. 72, pgs. 3961-3965 (1975); or Benton et al., Science, Vol. 196, pgs. 180-183 (1977) or Woo, Methods in Enzymology, Vol. 68, pgs. 389-396 (1979). Alternatively, libraries can be screened with labeled oligonucleotide probes whose sequences are determined from the nucleotide sequences of the cDNA inserts of pcD(SRα)-F115, pH5C, and pH15C. Such probes can be synthesized on commercially available DNA synthesizers, e.g. Applied Biosystems model 381A, using standard techniques, e.g. Gait, Oligonucleotide Synthesis: A Practical Approach, (IRL Press, Washington D.C., 1984). In either case, it is preferable that the probe be at least 18-30 bases long. More preferably, the probe is at least 50-200 bases long. Hybridization probes can also be used to screen candidate sources of CSIF mRNA prior to library construction.
A wide range of single-cell and multicellular expression systems (i.e. host-expression vector combinations) can be used to produce the proteins of the invention. Possible types of host cells include, but are not limited to, bacterial, yeast, insect, mammalian, and the like. Many reviews are available which provide guidance for making choices and/or modifications of specific expression systems, e.g. to name a few, de Boer and Shepard, “Strategies for Optimizing Foreign Gene Expression in Escherichia coli ,” pgs. 205-247, in Kroon, ed. Genes: Structure and Expression (John Wiley & Sons, New York, 1983), review several E. coli expression systems; Kucherlapati et al., Critical Reviews in Biochemistry, Vol. 16, Issue 4, pgs. 349-379 (1984), and Banerji et al., Genetic Engineering, Vol. 5, pgs. 19-31 (1983) review methods for transfecting and transforming mammalian cells; Reznikoff and Gold, eds., Maximizing Gene Expression (Butterworths, Boston, 1986) review selected topics in gene expression in E. coli , yeast, and mammalian cells; and Thilly, Mammalian Cell Technology (Butterworths, Boston, 1986) reviews mammalian expression systems. Likewise, many reviews are available which describe techniques and conditions for linking and/or manipulating specific cDNAs and expression control sequences to create and/or modify expression vectors suitable for use with the present invention, e.g. Sambrook et al (cited above).
An E. coli expression system is disclosed by Riggs in U.S. Pat. No. 4,431,739, which is incorporated by reference. A particularly useful prokaryotic promoter for high expression in E. coli is the tac promoter, disclosed by de Boer in U.S. Pat. No. 4,551,433, which is incorporated herein by reference. Secretion expression vectors are also available for E. coli hosts. Particularly useful are the pIN-III-ompA vectors, disclosed by Ghrayeb et al., in EMBO J ., Vol. 3, pgs. 2437-2442 (1984), in which the cDNA to be transcribed is fused to the portion of the E. coli OmpA gene encoding the signal peptide of the ompA protein which, in turn, causes the mature protein to be secreted into the periplasmic space of the bacteria. U.S. Pat. Nos. 4,336,336 and 4,338,397 also disclose secretion expression vectors for prokaryotes. Accordingly, these references are incorporated by reference.
Numerous stains of bacteria are suitable hosts for prokaryotic expression vectors including strains of E. coli , such as W3110 (ATCC No. 27325), JA221, C600, ED767, DH1, LE392, HB101, X1776 (ATCC No. 31244), X2282, RR1 (ATCC No. 31343) MRCI; strains of Bacillus subtilus; and other enterobacteriaceae such as Salmonella typhimurium or Serratia marcescens, and various species of Pseudomonas. General methods for deriving bacterial strains, such as E. coli K12 X1776, useful in the expression of eukaryotic proteins is disclosed by Curtis III in U.S. Pat. No. 4,190,495. Accordingly this patent is incorporated by reference.
In addition to prokaryotic and eukaryotic microorganisms, expression systems comprising cells derived from multicellular organism may also be used to produce proteins of the invention. Of particular interest are mammalian expression systems because their posttranslational processing machinery is more likely to produce biologically active mammalian proteins. Several DNA tumor viruses have been used as vectors for mammalian hosts. Particularly important are the numerous vectors which comprise SV40 replication, transcription, and/or translation control sequences coupled to bacterial replication control sequences, e.g. the pcD vectors developed by Okayama and Berg, disclosed in Mol. Cell. Biol., Vol. 2, pgs. 161-170 (1982) and Mol. Cell. Biol., Vol. 3, pgs. 280-289 (1983), and improved by Takebe et al, Mol. Cell. Biol., Vol. 8, pgs. 466-472 (1988). Accordingly, these references are incorporated herein by reference. Other SV40-based mammalian expression vectors include those disclosed by Kaufman and Sharp, in Mol. Cell. Biol., Vol. 2, pgs. 1304-1319 (1982), and Clark et al., in U.S. Pat. No. 4,675,285, both of which are incorporated herein by reference. Monkey cells are usually the preferred hosts for the above vectors. Such vectors containing the SV40 ori sequences and an intact A gene can replicate autonomously in monkey cells (to give higher copy numbers and/or more stable copy numbers than nonautonomously replicating plasmids). Moreover, vectors containing the SV40 ori sequences without an intact A gene can replicate autonomously to high copy numbers (but not stably) in COS7 monkey cells, described by Gluzman, Cell, Vol. 23, pgs. 175-182 (1981) and available from the ATCC (accession no. CRL 1651). The above SV40-based vectors are also capable of transforming other mammalian cells, such as mouse L cells, by integration into the host cell DNA.
Multicellular organisms can also serve as hosts for the production of CSIF, e.g. insect larvae, Maeda et al, Nature, Vol. 315, pgs. 592-594 (1985) and Ann. Rev. Entomol., pgs. 351-372 (1989); and transgenic animals, Jaenisch, Science, Vol. 240, pgs. 1468-1474 (1988).
II. In Vitro Assays for CSIF
CSIF activity is the property of inhibiting the synthesis of at least one cytokine in the group consisting of IFN-γ, lymphotoxin, IL-2, IL-3, and GM-CSF in a population of T helper cells induced to synthesize one or more of these cytokines by exposure to syngeneic antigen presenting cells (APCs) and antigen. Preferably, the APCs are treated so that they are incapable of replication, but that their antigen processing machinery remains functional. This is conveniently accomplished by irradiating the APCs, e.g. with about 1500-3000 R (gamma or X-radiation) before mixing with the T cells.
Alternatively, cytokine inhibition may be assayed in primary or, preferably, secondary mixed lymphocyte reactions (MLR), in which case syngeneic APCs need not be used. MLRs are well known in the art, e.g. Bradley, pgs. 162-166, in Mishell et al, eds. Selected Methods in Cellular Immunology (Freeman, San Francisco, 1980); and Battisto et al, Meth. in Enzymol., Vol. 150, pgs. 83-91 (1987). Briefly, two populations of allogenic lymphoid cells are mixed, one of the populations having been treated prior to mixing to prevent proliferation, e.g. by irradiation. Preferably, the cell populations are prepared at a concentration of about 2×10 6 cells/ml in supplemented medium, e.g. RPMI 1640 with 10% fetal calf serum. For both controls and test cultures, mix 0.5 ml of each population for the assay. For a secondary MLR, the cells remaining after 7 days in the primary MLR are re-stimulated by freshly prepared, irradiated stimulator cells. The sample suspected of containing CSIF may be added to the test cultures at the time of mixing, and both controls and test cultures may be assayed for cytokine production from 1 to 3 days after mixing.
Obtaining T cell populations and/or APC populations for CSIF assays employs techniques well known in the art which are fully described in DiSabato et al, eds., Meth. in Enzymol., Vol. 108 (1984). APCs for the preferred CSIF assay are peripheral blood monocytes. These are obtained using standard techniques, e.g. as described by Boyum, Meth. in Enzymol., Vol. 108, pgs. 88-102 (1984); Mage, Meth. in Enzymol., Vol. 108, pgs. 118-132 (1984); Litvin et al., Meth. in Enzymol., Vol. 108, pgs. 298-302 (1984); Stevenson, Meth. in Enzymol., Vol. 108, pgs. 242-249 (1989); and Romain et al, Meth. in Enzymol., Vol. 108, pgs. 148-153 (1984), which references are incorporated by reference. Preferably, helper T cells are used in the CSIF assays, which are obtained by first separating lymphocytes from the peripheral blood then selecting, e.g. by panning or flow cytometry, helper cells using a commercially available anti-CD4 antibody, e.g. OKT4 described in U.S. Pat. No. 4,381,295 and available from Ortho Pharmaceutical Corp. The requisite techniques are fully disclosed in Boyum, Scand. J. Clin. Lab. Invest., Vol. 21 (Suppl. 97), pg. 77 (1968); Meth. in Enzymol., Vol. 108 (cited above), and in Bram et al, Meth. in Enzymol., Vol. 121, pgs. 737-748 (1986). Generally, PBLs are obtained from fresh blood by Ficoll-Hypaque density gradient centrifugation.
A variety of antigens can be employed in the assay, e.g. Keyhole limpet hemocyanin (KLH), fowl γ-globulin, or the like. More preferably, in place of antigen, helper T cells are stimulated with anti-CD3 monoclonal antibody, e.g. OKT3 disclosed in U.S. Pat. No. 4,361,549, in the assay.
Cytokine concentrations in control and test samples are measured by standard biological and/or immunochemical assays. Construction of immunochemical assays for specific cytokines is well known in the art when the purified cytokine is available, e. g. Campbell, Monoclonal Antibody Technology (Elsevier, Amsterdam, 1984); Tijssen, Practice and Theory of Enzyme Immunoassays (Elsevier, Amsterdam, 1985); and U.S. Pat. No. 4,486,530 are exemplary of the extensive literature on the subject. ELISA kits for human IL-2, human IL-3, and human GM-CSF are commercially available from Genzyme Corp. (Boston, Mass.); and an ELISA kit for human IFN-γ is commercially available from Endogen, Inc. (Boston, Mass.). Polyclonal antibodies specific for human lymphotoxin are available from Genzyme Corp. which can be used in a radioimmunoassay for human lymphotoxin, e.g. Chard, An Introduction to Radioimmunoassay and Related Techniques (Elsevier, Amsterdam, 1982).
Biological assays of the cytokines listed above can also be used to determine CSIF activity. A biological assay for human lymphotoxin is disclosed in Aggarwal, Meth. in Enzymol., Vol. 116, pgs. 441-447 (1985), and Matthews et al, pgs. 221-225, in Clemens et al, eds., Lymphokines and Interferons: A Practical Approach (IRL Press, Washington, D.C., 1987). Human IL-2 and GM-CSF can be assayed with factor dependent cell lines CTLL-2 and KG-1, available from the ATCC under accession numbers TIB 214 and CCL 246, respectively. Human IL-3 can be assayed by it ability to stimulate the formation of a wide range of hematopoietic cell colonies in soft agar cultures, e.g. as described by Metcalf, The Hemopoietic Colony Stimulating Factors (Elsevier, Amsterdam, 1984). INF-γ can be quantified with anti-viral assays, e.g. Meager, pgs. 129-147, in Clemens et al, eds. (cited above).
Cytokine production can also be determined by mRNA analysis. Cytokine mRNAs can be measured by cytoplasmic dot hybridization as described by White et al., J. Biol. Chem., Vol. 257, pgs. 8569-8572 (1982) and Gillespie et al., U.S. Pat. No. 4,483,920. Accordingly, these references are incorporated by reference. Other approaches include dot blotting using purified RNA, e.g. chapter 6, in Hames et al., eds., Nucleic Acid Hybridization A Practical Approach (IRL Press, Washington, D.C., 1985). Generally, cytoplasmic dot hybridization involves anchoring mRNA from a cell or tissue sample onto a solid phase support, e.g. nitrocellulose, hybridizing a DNA probe to the anchored mRNA, and removing probe sequences nonspecifically bound to the solid phase support or forming mismatched hybrids with the mRNA so that only probe sequences forming substantially perfect hybrids with target mRNAs remain. The amount of DNA probe remaining is a measure of the number of target mRNA anchored to the solid phase support. The amount of DNA probe remaining is determined by the signal generated by its label. Several standard techniques are available for labeling single and double stranded nucleic acid fragments. They include incorporation of radioactive labels, e.g. Harper et al., Chromosoma, Vol. 83, pgs. 431-439 (1984); direct attachment of fluorescent labels, e.g. Smith et al., Nucleic Acids Research, Vol. 13, pgs. 2399-2412 (1985), and Connolly et al., Nucleic Acids Research, Vol. 13, pgs. 4485-4502 (1985); and various chemical modifications of the nucleic acid fragments that render them detectable immunochemically or by other affinity reactions, e.g. Tchen et al., Proc. Natl. Acad. Sci., Vol. 81, pgs. 3466-3470 (1984); Richardson et al., Nucleic Acids Research, Vol. 11, pgs. 6167-6184 (1983); Langer et al., Proc. Natl. Acad. Sci., Vol. 78, pgs. 6633-6637 (1981); Brigati et al., Virology, Vol. 126, pgs. 32-50 (1983); Broker et al., Nucleic Acids Research, Vol. 5, pgs. 363-384 (1978); and Bayer et al., Methods of Biochemical Analysis, Vol. 26, pgs. 1-45 (1980).
Preferably mRNA from T cells is anchored for hybridization to the probe by the following protocol. Isolated T cells are lysed by suspending in a lysis buffer (0.14 M NaCl, 1.5 mM MgCl 2 , 10 mM Tris-HCl pH 8.6, 0.5% Nonidet P-40 (a nonionic detergent, e.g. from Sigma)) at 4° C. at a final concentration of 1×10 8 cells/ml. The suspension is vortexed for 10 sec and the nuclei are pelleted (13,000 g, 2.5 min). The resulting cytoplasmic lysates are then transferred to a sterile 1.5 ml tube containing 0.3 volumes of 20×SSC (1×SSC=0.15 M NaCl, 0.015 M trisodium citrate (standard saline citrate)) and 0.2 volumes of 37% (w/w) formaldehyde. The mixture is then incubated at 60° C. for 15 min and stored in aliquots at −70° C. For analysis, 15 ml of each sample is titered by serial three fold dilutions in 15×SSC into a 96-well flat-bottomed microtiter plate (Falcon, Becton Dickinson, Oxnard, Calif.) in 0.1 ml. Each dilution is applied with suction to a sheet of Nytran (a modified nylon support available from Schleicher and Schuell, Keene, NH; 0.45 mm pore size) supported on a filter paper (Whatman 3 mmChr, Whatman Inc., Clifton, N.J.) utilizing a 96 hold Minifold apparatus (Schleicher and Schuell). The Nytran paper is then baked (80° C., 2 H) and treated with a prehybridization solution consisting of 50% formamide (BRL, Gaithersburg, Md.) 6×SSC, 50 mg/ml E. coli tRNA (Sigma), 0.2% (w/v) each of ficoll (MW=400,000), polyvinylpyrollidone, and bovine serum albumin (BSA). The probe is applied to the Nytran support at a concentrate of about 50 ng probe/ml of prehybridization solution. Following hybridization, the support is washed two times for 15 min each at room temperature in 2×SSC, then twice for 30 min each at 60° C. in 2×SSC/0.5% SDS. The support is then exposed to film using an intensifying screen and quantitated by scanning with a laser densitometer (e.g. Ultroscan XL, LKB Instruments Inc., Gaithersburg, Md.). If cytoplasmic dot hybridization lacks sufficient sensitivity, preferably the RNA is first extracted from the PBLs prior to blotting. For example, RNA may be extracted by the guanidinium thiocyanate method disclosed by Chirgwin et al., in Biochemistry, Vol. 18, pgs. 5294-5299 (1979).
In some cases, samples to be tested for CSIF activity must be pretreated to remove predetermined cytokines that might interfere with the assay. For example, IL-2 increases the production of IFN-γ in some cells. Thus depending on the helper T cells used in the assay, IL-2 may have to be removed from the sample being tested. Such removals are conveniently accomplished by passing the sample over a standard anti-cytokine affinity column.
III. Monoclonal Antibodies and Antagonists Specific for CSIF
Preferably, antagonists of the invention are derived from antibodies specific for human CSIF. More preferably, the antagonists of the invention comprise fragments or binding compositions specific for human CSIF. Antibodies comprise an assembly of polypeptide chains linked together by disulfide bridges. Two major polypeptide chains, referred to as the light chain and the heavy chain, make up all major structural classes (isotypes) of antibody. Both heavy chains and light chains are further divided into subregions referred to as variable regions and constant regions. Heavy chains comprise a single variable region and three different constant regions, and light chains comprise a single variable region (different from that of the heavy chain) and a single constant region (different from those of the heavy chain). The variable regions of the heavy chain and light chain are responsible for the antibody's binding specificity.
As used herein, the term “heavy chain variable region” means a polypeptide (1) which is from 110 to 125 amino acids in length, and (2) whose amino acid sequence corresponds to that of a heavy chain of a monoclonal antibody of the invention, starting from the heavy chain's N-terminal amino acid. Likewise, the term “light chain variable region” means a polypeptide (1) which is from 95 to 115 amino acids in length, and (2) whose amino acid sequence corresponds to that of a light chain of a monoclonal antibody of the invention, starting from the light chain's N-terminal amino acid.
As used herein the term “monoclonal antibody” refers to homogeneous populations of immunoglobulins which are capable of specifically binding to human CSIF.
As used herein the term “binding composition” means a composition comprising two polypeptide chains (1) which, when operationally associated, assume a conformation having high binding affinity for human CSIF, and (2) which are derived from a hybridoma producing monoclonal antibodies specific for human CSIF. The term “operationally associated” is meant to indicate that the two polypeptide chains can be positioned relative to one another for binding by a variety of means, including by association in a native antibody fragment, such as Fab or Fv, or by way of genetically engineered cysteine-containing peptide linkers at the carboxyl termini. Normally, the two polypeptide chains correspond to the light chain variable region and heavy chain variable region of a monoclonal antibody specific for human CSIF. Preferably, antagonists of the invention are derived from monoclonal antibodies specific for human CSIF. Monoclonal antibodies capable of blocking, or neutralizing, CSIF are selected by their ability to inhibit CSIF-induced effects in standard CSIF bioassays, e.g. inhibition of IFN-γ synthesis.
Hybridomas of the invention are produced by well known techniques. Usually, the process involves the fusion of an immortalizing cell line with a B-lymphocyte which produces the desired antibody. Alternatively, non-fusion techniques for generating an immortal antibody producing cell lines are possible, and come within the purview of the present invention, e.g. virally induced transformation: Casali et al., “Human Monoclonals from Antigen-Specific Selection of B Lymphocytes and Transformation by EBV,” Science, Vol. 234, pgs. 476-479 (1986). Immortalizing cell lines are usually transformed mammalian cells, particularly myeloma cells of rodent, bovine, and human origin. Most frequently, rat or mouse myeloma cell lines are employed as a matter of convenience and availability. Techniques for obtaining the appropriate lymphocytes from mammals injected with the target antigen are well known. Generally, either peripheral blood lymphocytes (PBLs) are used if cells of human origin are desired, or spleen cells or lymph node cells are used if non-human mammalian sources are desired. A host mammal is injected with repeated dosages of the purified antigen, and the mammal is permitted to generate the desired antibody producing cells before these are harvested for fusion with the immortalizing cell line. Techniques for fusion are also well known in the art, and in general, involve mixing the cells with a fusing agent, such as polyethylene glycol. Hybridomas are selected by standard procedures, such as HAT selection. From among these hybridomas, those secreting the desired antibody, i.e. specific for human CSIF, are selected by assaying their culture medium by standard immunoassays, such as Western blotting, ELISA, RIA, CSIF neutralizing capability, or the like. Antibodies are recovered from the medium using standard protein purification techniques, e.g. Tijssen, Practice and Theory of Enzyme Immunoassays (Elsevier, Amsterdam, 1985). Many references are available for guidance in applying any of the above techniques, e.g. Kohler et al., Hybridoma Techniques (Cold Spring Harbor Laboratory, New York, 1980); Tijsscn, Practice and Theory of Enzyme Immunoassays (Elsevier, Amsterdam, 1985); Campbell, Monoclonal Antibody Technology (Elsevier, Amsterdam, 1984); Hurrell, Monoclonal Hybridoma Antibodies: Techniques and Applications (CRC Press, Boca Raton, Fla., 1982); and the like. Hybridomas producing monoclonal antibodies specific for human CSIF are then subjected to a second screen using the CSIF assays described above to select ones capable of blocking, or neutralizing, the biological activity of CSIF.
The use and generation of fragments of antibodies is also well known, e.g. Fab fragments: Tijssen, Practice and Theory of Enzyme Immunoassays (Elsevier, Amsterdam, 1985); and Fv fragments: Hochman et al. Biochemistry, Vol. 12, pgs. 1130-1135 (1973), Sharon et al., Biochemistry, Vol. 15, pgs. 1591-1594 (1976) and Ehrlich et al., U.S. Pat. No. 4,355,023; and antibody half molecules: Auditore- Hargreaves, U.S. Pat. No. 4,470,925.
Antibodies and antibody fragments characteristic of hybridomas of the invention can also be produced by recombinant means by extracting messenger RNA, constructing a cDNA library, and selecting clones which encode segments of the antibody molecule, e.g. Wall et al., Nucleic Acids Research, Vol. 5, pgs. 3113-3128 (1978); Zakut et al., Nucleic Acids Research, Vol. 8, pgs. 3591-3601 (1980); Cabilly et al., Proc. Natl. Acad. Sci., Vol. 81, pgs. 3273-3277 (1984); Boss et al., Nucleic Acids Research, Vol. 12, pgs. 3791-3806 (1984); Amster et al., Nucleic Acids Research, Vol. 8, pgs. 2055-2065 (1980); Moore et al., U.S. Pat. No. 4,642,334; Skerra et al, Science, Vol. 240, pgs. 1038-1041(1988); and Huse et al, Science, Vol. 246, pgs. 1275-1281 (1989). In particular, such techniques can be used to produce interspecific monoclonal antibodies, wherein the binding region of one species is combined with non-binding region of the antibody of another species to reduce immunogenicity, e.g. Liu et al., Proc. Natl. Acad. Sci., Vol. 84, pgs. 3439-3443 (1987).
IV. Purification and Pharmaceutical Compositions
When polypeptides of the present invention are expressed in soluble form, for example as a secreted product of transformed yeast or mammalian cells, they can be purified according to standard procedures of the art, including steps of ammonium sulfate precipitation, ion exchange chromatography, gel filtration, electrophoresis, affinity chromatography, and/or the like, e.g. “Enzyme Purification and Related Techniques,” Methods in Enzymology, 22:233-577 (1977), and Scopes, R., Protein Purification: Principles and Practice (Springer-Verlag, N.Y., 1982) provide guidance in such purifications. Likewise, when polypeptides of the invention are expressed in insoluble form, for example as aggregates, inclusion bodies, or the like, they can be purified by standard procedures in the art, including separating the inclusion bodies from disrupted host cells by centrifugation, solublizing the inclusion bodies with chaotropic and reducing agents, diluting the solubilized mixture, and lowering the concentration of chaotropic agent and reducing agent so that the polypeptide takes on a biologically active conformation. The latter procedures are disclosed in the following references, which are incorporated by reference: Winkler et al, Biochemistry, 25: 4041-4045 (1986); Winkler et al, Biotechnology, 3: 992-998 (1985); Koths et al, U.S. Pat. No. 4,569,790; and European patent applications 86306917.5 and 86306353.3.
As used herein “effective amount” means an amount sufficient to ameliorate a symptom of an autoimmune condition. The effective amount for a particular patient may vary depending on such factors as the state of the autoimmune condition being treated, the overall health of the patient, method of administration, the severity of side-effects, and the like. Generally, CSIF is administered as a pharmaceutical composition comprising an effective amount of CSIF and a pharmaceutical carrier. A pharmaceutical carrier can be any compatible, non-toxic substance suitable for delivering the compositions of the invention to a patient. Generally, compositions useful for parenteral administration of such drugs are well known, e.g. Remington's Pharmaceutical Science, 15th Ed. (Mack Publishing Company, Easton, Pa. 1980). Alternatively, compositions of the invention may be introduced into a patient's body by implantable or injectable drug delivery system, e.g. Urquhart et al., Ann. Rev. Pharmacol. Toxicol., Vol. 24, pgs. 199-236 (1984); Lewis, ed. Controlled Release of Pesticides and Pharmaceuticals (Plenum Press, New York, 1981); U.S. Pat. No. 3,773,919; U.S. Pat. No. 3,270,960; and the like.
When administered parenterally, the CSIF is formulated in a unit dosage injectable form (solution, suspension, emulsion) in association with a pharmaceutical carrier. Examples of such carriers are normal saline, Ringer's solution, dextrose solution, and Hank's solution. Nonaqueous carriers such as fixed oils and ethyl oleate may also be used. A preferred carrier is 5% dextrose/saline. The carrier may contain minor amounts of additives such as substances that enhance isotonicity and chemical stability, e.g., buffers and preservatives. The CSIF is preferably formulated in purified form substantially free of aggregates and other proteins at a concentration in the range of about 5 to 20 μg/ml. Preferably, CSIF is administered by continuous infusion so that an amount in the range of about 50-800 μg is delivered per day (i.e. about 1-16 μg/kg/day). The daily infusion rate may be varied based on monitoring of side effects and blood cell counts.
CSIF can be purified from culture supernatants of mammalian cells transiently transfected or stably transformed by an expression vector carrying an CSIF gene. Preferably, CSIF is purified from culture supernatants of COS 7 cells transiently transfected by the pcD expression vector. Transfection of COS 7 cells with pcD proceeds as follows: One day prior to transfection, approximately 10 6 COS 7 monkey cells are seeded onto individual 100 mm plates in Dulbecco's modified Eagle medium (DME) containing 10% fetal calf serum and 2 mM glutamine. To perform the transfection, the medium is aspirated from each plate and replaced with 4 ml of DME containing 50 mM Tris.HCl pH 7.4, 400 mg/ml DEAE-Dextran and 50 μg of plasmid DNA. The plates are incubated for four hours at 37° C., then the DNA-containing medium is removed, and the plates are washed twice with 5 ml of serum-free DME. DME is added back to the plates which are then incubated for an additional 3 hrs at 37° C. The plates are washed once with DME, after which DME containing 4% fetal calf serum, 2 mM glutamine, penicillin (100 U/L) and streptomycin (100 μg/L) at standard concentrations is added. The cells are then incubated for 72 hrs at 37° C., after which the growth medium is collected for purification of CSIF. Alternatively, transfection can be accomplished by electroporation as described in the examples. Plasmid DNA for the transfections is obtained by growing pcD(SRα) containing the CSIF cDNA insert in E. coli MC1061, described by Casadaban and Cohcn, J. Mol. Biol., Vol. 138, pgs. 179-207 (1980), or like organism. The plasmid DNA is isolated from the cultures by standard techniques, e.g. Maniatis et al., Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory, New York, 1982).
When the antagonists of the inventions are derived from antibodies, they are normally administered parenterally, preferably intravenously. Since such protein or peptide antagonists may be immunogenic they are preferably administered slowly, either by a conventional IV administration set or from a subcutaneous depot, e.g. as taught by Tomasi et al, U.S. Pat. No. 4,732,863. When administered parenterally, the antibodies and/or fragments are formulated in a unit dosage injectable form in association with a pharmaceutical carrier, as described above. The antibody is preferably formulated in purified form substantially free of aggregates, other proteins, endotoxins, and the like, at concentrations of about 5 to 30 mg/ml, preferably 10 to 20 mg/ml. Preferably, the endotoxin levels are less than 2.5 EU/ml.
Selecting an administration regimen for an antagonist depends on several factors, including the serum turnover rate of the antagonist, the serum level of CSIF associated with the disorder being treated, the immunogenicity of the antagonist, the accessibility of the target CSIF (e.g. if non-serum CSIF is to be blocked), the relative affinity of CSIF to its receptor(s) versus CSIF to the antagonist, and the like. Preferably, an administration regimen maximizes the amount of antagonist delivered to the patient consistent with an acceptable level of side effects. Accordingly, the amount of antagonist delivered depends in part on the particular antagonist and the severity of the condition being treated. Guidance in selecting appropriate doses is found in the literature on therapeutic uses of antibodies, e.g. Bach et al., chapter 22, in Ferrone et al., eds., Handbook of Monoclonal Antibodies (Noges Publications, Park Ridge, N.J., 1985); and Russell, pgs. 303-357, and Smith et al., pgs. 365-389, in Haber et al., eds. Antibodies in Human Diagnosis and Therapy (Raven Press, New York, 1977). Preferably, whenever the antagonist comprises monoclonal antibodies or Fab-sized fragments thereof (including binding compositions), the dose is in the range of about 1-20 mg/kg per day. More preferably the dose is in the range of about 1-10 mg/kg per day.
V. Genetically Engineered Mutant CSIFs
Once nucleic acid sequence and/or amino acid sequence information is available for a native protein a variety of techniques become available for producing virtually any mutation in the native sequence, e.g.Shortle, in Science, Vol. 229, pgs. 1193-1201 (1985); Zoller and Smith, Methods in Enzymology, Vol. 100, pgs. 468-500 (1983); Mark et al., U.S. Pat. No. 4,518,584; Wells et al., in Gene, Vol. 34, pgs. 315-323 (1985); Estell et al., Science, Vol. 233, pgs. 659-663 (1986); Mullenbach et 20 al., J. Biol. Chem., Vol. 261, pgs. 719-722 (1986), and Feretti et al., Proc. Natl. Acad. Sci., Vol. 83, pgs. 597-603 (1986). Accordingly, these references are incorporated by refercnce.
Muteins of the natural polypeptide may be desirable in a variety of circumstances. For example, undesirable side effects might be reduced by certain muteins, particularly if the side effect activity is associated with a different part of the polypeptide from that of the desired activity. In some expression systems, the native polypeptide may be susceptible to degradation by proteases. In such cases, selected substitutions and/or deletions of amino acids which change the susceptible sequences can significantly enhance yields, e.g. British patent application 2173-804-A where Arg at position 275 of human tissue plasminogen activator is replaced by Gly or Glu. Muteins may also increase yields in purification procedures and/or increase shelf lives of proteins by eliminating amino acids susceptible to oxidation, acylation, alkylation, or other chemical modifications. For example, methionines readily undergo oxidation to form sulfoxides, which in many proteins is associated with loss of biological activity, e.g. Brot and Weissbach, Arch. Biochem. Biophys., Vol. 223, pg. 271 (1983). Often methionines can be replaced by more inert amino acids with little or no loss of biological activity, e.g. Australian patent application AU-A-52451/86. In bacterial expression systems, yields can sometimes be increased by eliminating or replacing conformationally in essential cysteine residues, e.g. Mark et al., U.S. Pat. No. 4,518,584.
Preferably cassette mutagenesis is employed to generate mutant proteins. A synthetic gene is constructed with a sequence of unique (when inserted in an appropriate vector) restriction endonuclease sites spaced approximately uniformly along the gene. The unique restriction sites allow segments of the gene to be conveniently excised and replaced with synthetic oligonucleotides (i.e. “cassettes”) which code for desired mutations. Determination of the number and distribution of unique restriction sites entails the consideration of several factors including (1) preexisting restriction sites in the vector to be employed in expression, (2) whether species or genera-specific codon usage is desired, (3) the number of different non-vector-cutting restriction endonucleases available (and their multiplicities within the synthetic gene), and (4) the convenience and reliability of synthesizing and/or sequencing the segments between the unique restriction sites.
The above technique is a convenient way to effect conservative amino acid substitutions, and the like, in the native protein sequence. “Conservative” as used herein means (i) that the alterations are as conformationally neutral as possible, that is, designed to produce minimal changes in the tertiary structure of the mutant polypeptides as compared to the native protein, and (ii) that the alterations are as antigenically neutral as possible, that is, designed to produce minimal changes in the antigenic determinants of the mutant polypeptides as compared to the native protein. Conformational neutrality is desirable for preserving biological activity, and antigenic neutrality is desirable for avoiding the triggering of immunogenic responses in patients or animals treated with the compounds of the invention. While it is difficult to select with absolute certainty which alternatives will be conformationally and antigenically neutral, rules exist which can guide those skilled in the art to make alterations that have high probabilities of being conformationally and antigenically neutral, e.g. Anfisen (cited above); Berzofsky, Science, Vol. 229, pgs. 932-940 (1985); and Bowie et al, Science, Vol. 247, pgs. 1306-1310 (1990). Some of the more important rules include (1) substitution of hydrophobic residues are less likely to produce changes in antigenicity because they are likely to be located in the protein's interior, e.g. Berzofsky (cited above) and Bowie et al (cited above); (2) substitution of physiochemically similar, i.e. synonymous, residues are less likely to produce conformational changes because the replacement amino acid can play the same structural role as the substituted amino acid; and (3) alteration of evolutionarily conserved sequences is likely to produce deleterious conformational effects because evolutionary conservation suggests sequences may be functionally important. In addition to such basic rules for selecting mutein sequences, assays are available to confirm the biological activity and conformation of the engineered molecules. Biological assays for the polypeptides of the invention are described more fully above. Changes in conformation can be tested by at least two well known assays: the microcomplement fixation method, e.g. Wasserman et al., J. Immunol., Vol. 87, pgs. 290-295 (1961), or Levine et al. Methods in Enzymology, Vol. 11, pgs. 928-936 (1967) used widely in evolutionary studies of the tertiary structures of proteins; and affinities to sets of conformation-specific monoclonal antibodies, e.g. Lewis et al., Biochemistry, Vol. 22, pgs. 948-954 (1983).
VI. Human CSIF Peptide Antibodies
The invention includes peptides derived from human CSIF, and immunogens comprising conjugates between carriers and peptides of the invention. The term immunogen as used herein refers to a substance which is capable of causing an immune response. The term carrier as used herein refers to any substance which when chemically conjugated to a peptide of the invention permits a host organism immunized with the resulting conjugate to generate antibodies specific for the conjugated peptide. Carriers include red blood cells, bacteriophages, proteins, or synthetic particles such as agarose beads. Preferably, carriers are proteins, such as serum albumin, gamma-globulin, keyhole limpet hemocyanin, thyroglobulin, ovalbumin, fibrinogen, or the like.
Peptides of the invention are synthesized by standard techniques, e.g. Stewart and Young, Solid Phase Peptide Synthesis, 2nd Ed. (Pierce Chemical Company, Rockford, Ill., 1984). Preferably, a commercial peptide synthesizer is used, e.g. Applied Biosystems, Inc. (Foster City, Calif.) model 430A. Peptides of the invention are assembled by solid phase synthesis on a cross-linked polystyrene support starting from the carboxyl terminal residue and adding amino acids in a stepwise fashion until the entire peptide has been formed. The following references are guides to the chemistry employed during synthesis: Merrifield, J. Amer. Chem. Soc., Vol. 85, pg. 2149 (1963); Kent et al., pg 185, in Peptides 1984, Ragnarsson, Ed. (Almquist and Weksell, Stockholm, 1984); Kent et al., pg. 217 in Peptide Chemistry 84, Izumiya, Ed. (Protein Research Foundation, B. H. Osaka, 1985); Merrifield, Science, Vol. 232, pgs. 341-347 (1986); Kent, Ann. Rev. Biochem., Vol. 57, pgs. 957-989 (1988), and references cited in these latter two references.
In solid state synthesis it is most important to eliminate synthesis by-products, which are primarily termination, deletion, or modification peptides. Most side reactions can be eliminated or minimized by use of clean, well characterized resins, clean amino acid derivatives, clean solvents, and the selection of proper coupling and cleavage methods and reaction conditions, e.g. Barany and Merrifield, The Peptides, Cross and Meienhofer, Eds., Vol. 2, pgs 1-284 (Academic Press, New York, 1979). It is important to monitor coupling reactions to determine that they proceed to completion so that deletion peptides missing one or more residues will be avoided. The quantitative ninhydrin reaction is useful for that purpose, Sarin et al. Anal. Biochem, Vol. 117, pg 147 (1981). Na-t-butyloxycarbonyl (t-Boc)—amino acids are used with appropriate side chain protecting groups stable to the conditions of chain assembly but labile to strong acids. After assembly of the protected peptide chain, the protecting groups are removed and the peptide anchoring bond is cleaved by the use of low then high concentrations of anhydrous hydrogen fluoride in the presence of a thiocster scavenger, Tam et al., J. Amer. Chem. Soc., Vol. 105, pg. 6442 (1983). Side chain protecting groups used are Asp(OBzl), Glu(OBzl), Ser(Bzl), Thr(Bzl), Lys(Cl-Z), Tyr(Br-Z), Arg(NGTos), Cys(4-MeBzl), and His(ImDNP). (Bzl, benzyl; Tos toluene sulfoxyl; DNP, dinitrophenyl; Im, imidazole; Z, benzyloxgycarbonyl). The remaining amino acids have no side chain protecting groups. For each cycle the tBoc Na protected peptide-resin is exposed to 65 percent trifluoroacetic acid (from Eastman Kodak) (distilled before use) in dichloromethane (DCM), (Mallenckrodt): first for 1 minute then for 13 minutes to remove the Na-protecting group. The peptide-resin is washed in DCM, neutralized twice with 10 percent diisopropylethylamine (DIEA) (Aldrich) in dimethylformamide (DMF) (Applied Biosystems), for 1 minute each. Neutralization is followed by washing with DMF. Coupling is performed with the symmetric anhydride of the amino acid in DMF for 16 minutes. The symmetric anhydride is prepared on the synthesizer by dissolving 2 mmol of amino acid in 6 ml of DCM and adding 1 mmol of dicyclohexycarbodiimide (Aldrich) in 2 ml of DCM. After 5 minutes, the activated amino acid is transferred to a separate vessel and the DCM is evaporated by purging with a continuous stream of nitrogen gas. The DCM is replaced by DMF (6 ml total) at various stages during the purging. After the first coupling, the peptide-resin is washed with DCM, 10 percent DIEA in DCM, and then with DCM. For recoupling, the same amino acid and the activating agent, dicyclohexylcarbodiimide, are transferred sequentially to the reaction vessel. After activation in situ and coupling for 10 minutes, sufficient DMF is added to make a 50 percent DMF-DCM mixture, and the coupling is continued for 15 minutes. Arginine is coupled as a hydroxybenzotriazole (Aldrich) ester in DMF for 60 minutes and then recoupled in the same manner as the other amino acids. Asparagine and glutamine are coupled twice as hydroxybenzotriazole esters in DMF, 40 minutes for each coupling. For all residues, the resin is washed after the second coupling and a sample is automatically taken for monitoring residual uncoupled α-amine by quantitative ninhydrin reaction, Sarin et al. (cited above).
The general technique of linking synthetic peptides to a carrier is described in several references, e.g. Walter and Doolittle, “Antibodies Against Synthetic Peptides,” in Setlow et al., eds., Genetic Engineering, Vol. 5, pgs. 61-91 (Plenum Press, N.Y., 1983); Green et al. Cell, Vol. 28, pgs. 477-487 (1982); Lemer et al., Proc. Natl. Acad. Sci., Vol. 78, pgs. 3403-3407 (1981); Shimizu et al., U.S. Pat. No. 4,474,754; and Ganfield et al., U.S. Pat. No. 4,311,639. Accordingly, these references are incorporated by reference. Also, techniques employed to link haptens to carriers are essentially the same as the above-referenced techniques, e.g. chapter 20 in Tijsseu Practice and Theory of Enzyme Immunoassays (Elsevier, New York, 1985). The four most commonly used schemes for attaching a peptide to a carrier are (1) glutaraldehyde for amino coupling, e.g. as disclosed by Kagan and Glick, in Jaffe and Behrman, eds. Methods of Hormone Radioimmunoassay, pgs. 328-329 (Academic Press, N.Y., 1979), and Walter et al. Proc. Natl. Acad. Sci., Vol. 77, pgs. 5197-5200 (1980); (2) water-soluble carbodiimides for carboxyl to amino coupling, e.g. as disclosed by Hoare et al., J. Biol. Chem., Vol. 242, pgs. 2447-2453 (1967); (3) bis-diazobenzidine (DBD) for tyrosine to tyrosine sidechain coupling, e.g. as disclosed by Bassiri et al., pgs. 46-47, in Jaffe and Behrman, eds. (cited above), and Walter et al. (cited above); and (4) maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) for coupling cysteine (or other sulfhydryls) to amino groups, e.g. as disclosed by Kitagawa et al., J. Biochem. (Tokyo), Vol. 79, pgs. 233-239 (1976), and Lerner et al. (cited above). A general rule for selecting an appropriate method for coupling a given peptide to a protein carrier can be stated as follows: the group involved in attachment should occur only once in the sequence, preferably at the appropriate end of the segment. For example, BDB should not be used if a tyrosine residue occurs in the main part of a sequence chosen for its potentially antigenic character. Similarly, centrally located lysines rule out the glutaraldehyde method, and the occurrences of aspartic and glutamic acids frequently exclude the carbodiimide approach. On the other hand, suitable residues can be positioned at either end of chosen sequence segment as attachment sites, whether or not they occur in the “native” protein sequence. Internal segments, unlike the amino and carboxy termini, will differ significantly at the “unattached end” from the same sequence as it is found in the native protein where the polypeptide backbone is continuous. The problem can be remedied, to a degree, by acetylating the α-amino group and then attaching the peptide by way of its carboxy terminus. The coupling efficiency to the carrier protein is conveniently measured by using a radioactively labeled peptide, prepared either by using a radioactive amino acid for one step of the synthesis or by labeling the completed peptide by the iodination of a tyrosine residue. The presence of tyrosine in the peptide also allows one to set up a sensitive radioimmune assay, if desirable. Therefore, tyrosine can be introduced as a terminal residue if it is not part of the peptide sequence defined by the native polypeptide.
Preferred carriers are proteins, and preferred protein carriers include bovine serum albumin, myoglobulin, ovalbumin (OVA), keyhole limpet hemocyanin (KLH), or the like. Peptides can be linked to KLH through cysteines by MBS as disclosed by Liu et al., Biochemistry, Vol. 18, pgs. 690-697 (1979). The peptides are dissolved in phosphate-buffered saline (pH 7.5), 0.1 M sodium borate buffer (pH 9.0) or 1.0 M sodium acetate buffer (pH 4.0). The pH for the dissolution of the peptide is chosen to optimize peptide solubility. The content of free cysteine for soluble peptides is determined by Ellman's method, Ellman, Arch. Biochem. Biophys., Vol. 82, pg. 7077 (1959). For each peptide, 4 mg KLH in 0.25 ml of 10 mM sodium phosphate buffer (pH 7.2) is reacted with 0.7 mg MBS (dissolved in dimethyl formamide) and stirred for 30 min at room temperature. The MBS is added dropwise to ensure that the local concentration of formamide is not too high, as KLH is insoluble in >30% formamide. The reaction product, KLH-MBS, is then passed through Sephadex G-25 equilibrated with 50 mM sodium phosphate buffer (pH 6.0) to remove free MBS, KLH recovery from peak fractions of the column eluate (monitored by OD280) is estimated to be approximately 80%. KLH-MBS is then reacted with 5 mg peptide dissolved 25 in 1 ml of the chosen buffer. The pH is adjusted to 7-7.5 and the reaction is stirred for 3 hr at room temperature. Coupling efficiency is monitored with radioactive peptide by dialysis of a sample of the conjugate against phosphate-buffered saline, and ranged from 8% to 60%. Once the peptide-carrier conjugate is available polyclonal or monoclonal antibodies are produced by standard techniques, e.g. as disclosed by Campbell, Monoclonal Antibody Technology (Elsevier, N.Y., 1984); Hurrell, ed. Monoclonal Hybridoma Antibodies: Techniques and Applications (CRC Press, Boca Raton, Fla., 1982); Schreier et al. Hybridoma Techniques (Cold Spring Harbor Laboratory, New York, 1980); U.S. Pat. No. 4,562,003; or the like. In particular, U.S. Pat. No. 4,562,003 is incorporated by reference.
Both polyclonal and monoclonal antibodies can be screened by ELISA. As in other solid phase immunoassays, the test is based on the tendency of macromolecules to adsorb nonspecifically to plastic. The irreversibility of this reaction, without loss of immunological activity, allows the formation of antigen-antibody complexes with a simple separation of such complexes from unbound material. To titrate antipeptide serum, peptide conjugated to a carrier different from that used in immunization is adsorbed to the wells of a 96-well microtiter plate. The adsorbed antigen is then allowed to react in the wells with dilutions of anti-peptide serum. Unbound antibody is washed away, and the remaining antigen-antibody complexes are allowed to react with antibody specific for the IgG of the immunized animal. this second antibody is conjugated to an enzyme such as alkaline phosphatase. A visible colored reaction product produced when the enzyme substrate is added indicates which wells have bound antipeptide antibodies. The use of spectrophotometer readings allows better quantification of the amount of peptide-specific antibody bound. High-titer antisera yield a linear titration curve between 10 −3 and 10 −5 dilutions.
EXAMPLES
The following examples serve to illustrate the present invention. Selection of vectors and hosts as well as the concentration of reagents, temperatures, and the values of other variable parameters are only to exemplify application of the present invention and are not to be considered as limitations thereof.
Example I
Biological Activities of Mouse CSIF
Mouse CSIF-containing supernatants from the several T cell clones were obtained by incubating the T cell clones (5×10 6 cells/ml) in serum free medium (RPMI 1640 lacking phenol red and containing 0.05 mM 2-mercaptoethanol and 20 mM HEPES) and concanavalin A (5 μg/ml) for 24 hours. The clones included cell lines, D9 described in U.S. Pat. No. 4,613,459, D10 (described below), MB2-1 described in Mosmann et al, J. Immunol., Vol. 136, pgs. 2348-2357 (1986), CDC25 and CDC35 described in Tony et al, J. Exp. Med., Vol. 161, pgs. 223- (1985), and M411-2 and M411-14 6. The T cell supernatants were assayed for their ability to suppress IFN-γ synthesis in the cell line HDK-1, described in Cherwinski, et al, J. Exp. Med., Vol. 166, pgs. 1229-1244(1987). Serial twofold dilutions of samples from each T cell clone were prepared in 96-well flat-bottomed microtiter trays in a volume of 0.05 ml. HDK-1 cells (5×10 4 cells per well) along with irradiated (2500 R) syngeneic APCs (spleen cells at 5×10 5 cells per well) and antigen (keyhole limpet hemocyanin at 150 μg/ml) were added in a volume of 0.15 ml. 11B11 anti-IL-4 antibody (10 μg/ml), described in Ohara et, Nature, Vol. 315, pgs.333-336 (1985), was added to samples suspected of containing IL-4. After incubation at 37° C. for 24 h, supernatants were collected and kept at 4° C. for periods of less than a week, or at −80° C. for longer periods. Levels of IFN-γ were assayed by two site sandwich ELISA using a rat anti-mouse IFN-γ monoclonal antibody, XMG1.2, and affinity-purified rabbit anti-mouse IFN-γ antibody. FIG. 1 shows the degree of inhibition of IFN-γ synthesis as percentage of control levels.
CSIF produced by D1O cells was partially purified and applied to two different T cell clones to examine the degree of cytokine synthesis inhibition as a function of CSIF concentration. The partially purified CSIF was prepared as follows: 1-2.5 L batches of concanavalin A-induced D10 supernatant were concentrated approximately 10-fold using Amicon YM-5 membranes (Amicon Corp. , Danvers, Mass.), passed through a 5-ml mannose-conjugated agarose column (E-Y Laboratories, San Mateo, Calif.), then further concentrated another 3- to 5-fold, for a total concentration of 30-50 fold. This material was then further purified by two steps of high performance liquid chromatography: first over a hydroxylapatite-based column (Bio-Gel HPHT, Bio-Rad Laboratories, Richmond, Calif.) and then over a gel filtration column (TSK-G 3000 SW, 60 cm length, LKB Instruments, Gaithersburg, Md.). One such batch of partially purified CSIF was kept in aliquots at −80° C. and used as a standard of CSIF activity. When initially assayed, this preparation caused approximately 50% inhibition of IFN-γ production at a dilution of 1/200 in an assay volume of 0.2 ml, and so a standard unit was defined by assigning a value of 1000 U/ml to the standard CSIF preparation. In each assay below, the CSIF activity in unknown samples was quantitated by comparing levels of inhibition of IFN-γ synthesis by the unknown to that of the standard. The T cell clones that were assayed for inhibition of cytokine synthesis were HDK-1 (described above) and MD13-10, described in Cell. Immunol., Vol. 97, pgs. 357- (1986). For the assay of IL-3 and GM-CSF levels the partially purified CSIF was further treated by passing it over anti-IL-3 and anti-GM-CSF affinity columns. Antibodies in 0.1 M NaCl, 0.1 M HEPES, and 0.08 M CaCl 2 were coupled to Affi-Gel 10 (Bio-Rad) at 4° C. with gentle mixing for 4 hours. Each 1-2 ml column contained approximately 10 to 20 mg of coupled antibody.
As shown in the table below, IFN-γ production was inhibited in both clones. The synthesis of the other cytokines, IL-2, lymphotoxin, IL-3, and GM-CSF was inhibited to a lesser degree or not at all in MD13-10 cells.
TABLE
% of Control Synthesis Level
Cell line
Cytokine
14 U/ml
42 U/ml
125 U/ml
HDK-1
IFN-g
47.6
29.1
18.6
IL-2
71.7
59.6
40.4
lymphotoxin
41.9
45.1
42.8
IL-3
63.9
52.6
38.4
GM-CSF
86.9
79.1
66.8
MD13-10
IFN-g
36.0
27.5
23.2
IL-2
88.2
109.3
96.0
IL-3
60.2
63.0
51.0
GM-CSF
109.0
119.9
97.6
Example II
Construction of cDNA Library from D10 Cells and Isolation of Clone pcD(SRα)-F115
A cDNA library was constructed in the pcD(SRα) vector from mRNA extracted from D10 cells, described in Kaye et al, J. Exp. Med., Vol. 158, pgs. 836- (1983), in accordance with the method of Okayama and Berg, Mol. Cell. Biol. 2: 161-170 (1982) and 3: 280-289 (1983), also disclosed in U.S. Pat. No. 4,695,542, which is incorporated by reference. The pcD(SRα) vectors carrying cDNA inserts were amplified in E. coli. Plasmid DNA was extracted from pools of these randomly picked clones and used to transfect COS 7 monkey cells as described below. The supernatants of the COS 7 cultures were then tested for CSIF activity. COS cells were transfected as follows: One day prior to transfection, approximately 1.5×10 6 COS 7 monkey cells were seeded onto individual 100 mm plates in Dulbecco's modified Eagle medium (DME) containing 5% fetal calf serum (FCS) and 2 mM glutamine. To perform the transfection, COS 7 cells were removed from the dishes by incubation with trypsin, washed twice in serum-free DME, and suspended to 10 7 cells/ml in serum-free DME. A 0.75 ml aliquot was mixed with 20 μg DNA and transferred to a sterile 0.4 cm electroporation cuvette. After 10 minutes, the cells were pulsed at 200 volts, 960 μF in a BioRad Gene Pulser unit. After another 10 minutes, the cells were removed from the cuvette and added to 20 ml of DME containing 5% FCS, 2 mM glutamine, penicillin, streptomycin, and gentamycin. The mixture was aliquoted to four 100 mm tissue culture dishes. After 12-24 hours at 37° C., 5% CO 2 , the medium was replaced with similar medium containing only 1% FCS and the incubation continued for an additional 72 hours at 37° C., 5% CO 2 , after which the medium was collected and assayed for CSIF activity. Subsequently, the sequence of the largest open reading frame of the cDNA insert of pcD(SRα)-F115 was determined as follows:
ATGCCTGGCT CAGCACCGCT ATGCTGCCTG CTCTTACTGA
CTGGCATGAG GATCAGCAGG GGCCAGTACA GCCGGGAAGA
CAATAACTGC ACCCACTTCC CAGTCGGCCA GAGCCACATG
CTCCTAGAGC TGCGGACTGC CTTCAGCCAG GTGAAGACTT
TCTTTCAAAC AAAGGACCAG CTGGACAACA TACTGCTAAC
CGACTCCTTA ATGCAGGACT TTAACCCTTA CTTGGGTTCA
CAAGCCTTAT CGGAAATGAT CCAGTTTTAC CTGGTAGAAG
TGATGCCCCA GGCAGAGAAG CATGGCCCAG AAATCAAGGA
GCATTTGAAT TCCCTGGGTG AGAAGCTGAA GACCCTCAGG
ATGCGGCTGA GGCGCTGTCA TCGATTTCTC CCCTGTGAAA
ATAAGAGCAA GGGAGFGGAG CAGGTGAAGA TGTATTTTAA
TAAGCTCCAA GACCAAGGTG TCTACAAGGC CATGAATGAA
TTTGACATCT TCATCAACTG CATAGAAGCA TACATGATGA
TCAAAATCAA AAGCTAA
and the amino acid sequence of the mature mouse CSIF protein determined by the Heijne algorthm is as follows:
QYSREDNNCTHFPVGQSHMLLELRTAFSQVKTFFQTKDQLDNIMLLTD
SLMQDFKGYLGCQALSEMIQFYLVEVMPQAEKHGPEIKEHLNSLGE
KLKTLRMRLRRCHRFLPCENKSKAVEQVKSDFNKLQDQGVYKAM
NEFDIFINCIEAYMMIKMKS
Example III
Screening cDNA Libraries for Human CSIF Using Probes Derived from pcD(SRα)-F115: Isolation of pH5C and pH15C
A cDNA library constructed in pcD(SRα) from mRNA extracted from a human T cell clone was screened with a collection of 70-mer oligonucleotides whose sequences were complementary to the coding and noncoding strands of the fragment of the mouse CSIF gene encoding mature CSIF. Standard hybridization protocols were used, e.g. bacterial colonies grown on 150 mm petri dishes were transferred to GeneScreen membranes, treated with the radioactively labeled oligonucleotide probes, washed, then exposed to X-ray film. The probes were hybridized under low stringency conditions for the length of the probes: prehybridization consisted of incubation of the target nucleic acids in 5×SET (20×SET is 3 M NaCl+0.4 Tris-Cl (pH 7.8)+20 mM EDTA) at 60° C., followed by hybridization under the same conditions, and washing in 5×SET at 50° C. Two clones carrying plasmids pH5C and pH15C were identified. Both plasmids expressed proteins in COS 7 cells that were capable of inhibiting IFN-γ synthesis in PHA-stimulated human PBLs. The cDNA insert of pH15C is illustrated in FIG. 4, and the nucleotide sequence of its largest open reading frame is given below:
5′-
ATGCACAGCT CAGCACTGCT CTGTTGCCTG GTCCTCCTGA CTGGGGTGAG-
GGCCAGCCCA GGCCAGGGCA CCCAGTCTGA GAACAGCTGC ACCCACTTCC-
CAGGCAACCT GCCTAACATG CTTCGAGATC TCCGAGCATGC CTTCAGCAGA-
GTGAAGACTT TCTTTCAAAT GAAGGATCAG CTGGACAACT TGTTGTTAAA-
GGAGTCCTTG CTGGAGGACT TTAAGGGTTA CCTGGGTTGC CAAGCCTTGT-
CTGAGATGAT CCAGTTTTAC CTGGAGGAGG TGATGCCCCA AGCTGAGAAC-
CAAGACCCAG ACATCAAGGC GCATGTGAAC TCCCTGGGGG AGAACCTRGAA-
GACCCTCAGG CTGAGGCTAC GGCGATGCA TCGATTTCTT CCCTGTGAAA-
ACAAGAGCAA GGCCGTGGAG CAGGTGAAGA ATGCCTTTAA TAAGCTCCAA-
GAGAAAGGCA TCTACAAAGC CATGAGTGAG TTTGACATCT TCATCAACTA-
CATAAAGCC TACATGAACAA TGAAGATACG AAACTGA-3′
Example IV
Monoclonal Antibodies Specific for CSTF
A male Lewis rat is immunized with semi-purified preparations of COS 7-cell expressed human CSIF. The rat is first immunized with approximately 50 μg of human CSIF in Freund's Complete Adjuvant, and boosted twice with the same amount of material in Freund's Incomplete Adjuvant. Test bleeds are taken. The animal is given a final boost of 25 μg in phosphate-buffered saline, and four days later the spleen is obtained for fusion.
Approximately 3×10 8 rat splenocytes are fused with an equal number of P3X63-AG8.653 mouse myeloma cells (available from the ATCC under accession number CRL 1580). 3840 microtiter plate wells are seeded at 5.7×10 4 parental myeloma cells per well. Standard protocols for the fusion and subsequent culturing of hybrids are followed, e.g. as described by Chretien et al, J. Immunol. Meth., Vol. 117, pgs. 67-81 (1989). 12 days after fusion supernatants are harvested and screened by indirect ELISA on PVC plates coated with COS 7-produced human CSIF. Hybridoma JES3-19F1.1.1 was identified in this manner and deposited with the American Type Culture Collection under accession number HB10487.
Hybridomas producing blocking antibodies are selected from the initially screened hybridomas by their ability to produce antibodies that counteract the CSIF-induced inhibition of IFN-γ synthesis in PHA-stimulated human PBLs.
Example V
Expression of Human CSIF in a Bacterial Host
A synthetic human CSIF gene is assembled from a plurality of chemically synthesized double stranded DNA fragments to form an expression vector designated TAC-RBS-hCSIF. Cloning and expression are carried out in a standard bacterial system, for example E. coli K-12 strain JM101, JM103, or the like, described by Viera and Messing, in Gene, Vol. 19, pgs. 259-268 (1982). Restriction endonuclease digestions and ligase reactions are performed using standard protocols, e.g. Maniatis et al., Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory, New York, 1982).
The alkaline method (Maniatis et al., cited above) is used for small scale plasmid preparations. For large scale preparations a modification of the alkaline method is used in which an equal volume of isopropanol is used to precipitate nucleic acids from the cleared lysate. Precipitation with cold 2.5 M ammonium acetate is used to remove RNA prior to cesium chloride equilibrium density centrifugation and detection with ethidium bromide.
For filter hybridizations Whatman 540 filter circles are used to lift colonies which are then lysed and fixed by successive treatments with 0.5M NaOH, 1.5M NaCl; 1M Tris.HCl pH8.0, 1.5M NaCl (2 min each); and heating at 80° C. 25 (30 min). Hybridizations are in 6×SSPE, 20% formamide, 0.1% sodium dodecylsulphate (SDS), 100 mg/ml E. coli tRNA, 100 mg/ml Coomassie Brilliant Blue G-250 (Bio-Rad) at 42° C. for 6 hrs using 32 P-labelled (kinased) synthetic DNAs. (20×SSPE is prepared by dissolving 174 g of NaCl, 27.6 g of NaH 2 PO 4 9H2O, and 7.4 g of EDTA in 800 ml of H2O. pH is adjusted to 7.4 with NaOH, volume is adjusted to 1 liter, and sterilized by autoclaving). Filters are washed twice (15 min, room temperature) with 1×SSPE, 0.1% SDS. After autoradiography (Fuji RX film), positive colonies are located by aligning the regrown colonies with the blue-stained colonies on the filters. DNA is sequenced by the dideoxy method, Sanger et al. Proc. Natl. Acad. Sci., Vol. 74, pg. 5463 (1977). Templates for the dideoxy reactions are either single stranded DNAs of relevant regions recloned into M13mp vectors, e.g. Messing et al. Nucleic Acids Res., Vol. 9, pg. 309 (1981), or double-stranded DNA prepared by the minialkaline method and denatured with 0.2M NaOH (5 min, room temperature) and precipitated from 0.2M NaOH, 1.43M ammonium acetate by the addition of 2 volumes of ethanol. DNA is synthesized by phosphoramidite chemistry using Applied Biosystems 380A synthesizers. Synthesis, deprotection, cleavage and purification (7M urea PAGE, elution, DEAE-cellulose chromotography) are done as described in the 380A synthesizer manual.
Complementary strands of synthetic DNAs to be cloned (400 ng each) are mixed and phosphorylated with polynucleotide kinase in a reaction volume of 50 ml. This DNA is ligated with 1 mg of vector DNA digested with appropriate restriction enzymes, and ligations are in a volume of 50 ml at room temperature for 4 to 12 hours. Conditions for phosphorylation, restriction enzyme digestions, polymerase reactions, and ligation have been described (Maniatis et al., cited above). Colonies are scored for lacZ+ (when desired) by plating on L agar supplemented with ampicillin, isopropyl-1-thio-beta-D-galactoside (IPTG) (0.4 mM) and 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (x-gal) (40 mg/ml).
The TAC-RBS vector is constructed by filling-in with DNA polymerase the single BamHI site of the tacP-bearing plasmid pDR540 (Pharmacia). This is then ligated to unphosphorylated synthetic oligonucleotides (Pharmacia) which form a double-stranded fragment encoding a consensus ribosome binding site (RBS, GTAAGGAGGTTTAAC). After ligation, the mixture is phosphorylated and religated with the SstI linker ATGAGCTCAT. This complex was then cleaved with SstI and EcoRI, and the 173 bp fragment isolated via polyacrylamide gel electrophoresis (PAGE) and cloned into EcoRI-SstI restricted pUC19 (Pharmacia) (as described below). The sequence of the RBS-ATG-polylinker regions of the final construction (called TAC-RBS) is shown in FIG. 3 .
The synthetic CSIF gene is assembled into a pUC19 plasmid in eight steps. At each step inserts free of deletions and/or inserts can be detected after cloning by maintaining the lacZ(α) gene of pUC19 in frame with the ATG start codon inserted in step 1. Clones containing deletion and/or insertion changes can be filtered out by scoring for blue colonies on L-ampicillin plates containing x-gal and IPTG. Alternatively, at each step sequences of inserts can be readily confirmed using a universal sequencing primer on small scale plasmid DNA preparations, e.g. available from Boehringer Mannheim.
In step 1 the TAC-RBS vector is digested with SstI, treated with T4 DNA polymerase (whose 3′ exonuclease activity digests the 3′ protruding strands of the SstI cuts to form blunt end fragments), and after deactivation of T4 DNA polymerase, treated with EcoRI to form a 173 base pair (bp) fragment containing the TAC-RBS region and having a blunt end at the ATG start codon and the EcoRI cut at the opposite end. Finally, the 173 bp TAC-RBS fragment is isolated.
In step 2 the isolated TAC-RBS fragment of step 1 is mixed with EcoRI/KpnI digested plasmid pUC19 and synthetic fragment 1A/B which, as shown below, has a blunt end at its upstream terminus and a staggered end corresponding to an KpnI cut at its downstream terminus. This KpnI end is adjacent to and downstream of a BstEII site. The fragments are ligated to form the pUC19 of step 2.
In step 3 synthetic fragment 2A/B and 3A/B (shown below) are mixed with BstEII/SmaI digested pUC19 of step 2 (after amplification and purification) and ligated to form pUC19 of step 3. Note that the downstream terminus of fragment 3A/B contains extra bases which form the SmaI blunt end. These extra bases are cleaved in step 4. Also fragments 2A/B and 3A/B have complementary 9 residue single stranded ends which anneal upon mixture, leaving the upstream BstEII cut of 2A/B and the downstream blunt end of 3A/B to ligate to the pUCl9.
In step 4 AflII/XbaI digested pUCl9 of step 3 (after amplification and purification) is repurified, mixed with synthetic fragment 4A/B (shown below), and ligated to form pUC19 of step 4.
In step 5 XbaI/SalI digested pUC19 of step 4 (after amplification and purification) is mixed with synthetic fragment 5A/B (shown below) and ligated to form the pUC19 of step 5. Note that the SalI staggered end of fragment 5A/B is eliminated by digestion with HpaI in step 6.
In step 6 HpaI/PstI digested pUC19 of step 5 (after amplification and purification) is mixed with synthetic fragment 6A/B (shown below) and ligated to form the pUC19 of step 6.
In step 7 ClaI/SphI digested pUC19 of step 6 (after amplification and purification) is mixed with synthetic fragment 7A/B (shown below) and ligated to form the pUC19 of step 7.
In step 8 MluI/HindIII digested pUC19 of step 7 (after amplification and purification) is mixed with synthetic fragments 8A/B and 9A/B and ligated to form the final construction. The final construction is inserted into E. coli K-12 strain JM101, e.g. available from the ATCC under accession number 33876, by standard techniques. After culturing, protein is extracted from the JM101 cells and dilutions of the extracts are tested for biological activity.
AGCCCAGGGC AGGGCACCCA GTCTYGAGAAC AGCTGCACCC ACTTC-
TCGGGTCCGG TCCCGTGGGT CAGACTCTTG TCGACGTGGG TGAAG-
CCAGGtAACC ggtac
GGTCCaTTGG c
Fragment 1A/B
GtAACCTGC TAACATGCTT CGAGATCTCC GAGATGCTT CAGCA-
GACGG ATTGTACGAA GCTCTAGAGG CTCTACGGAA GTCGT-
GAGTGAAGACTTTCTTT
CTCACTTC
Fragment 2A/B
CAAATGAAGG ATCAGCTGGA CAACTTGTTc TtAAG
TGAAAGAAA GTTTACTTCC TAGTCGACCT GTTGAACAAg AaTTC
Fragment 3A/B
GAGTCCTTGC TGGAGGACTT TAAGGGTTAC CTGGGTTGCC AAGCC-
CTCAGGAAGG ACCTCCTGAA ATTCCCAATG GACCCAACGG TTCGG-
TPGCCTGAGA TGATCCAGTT TTAt
AACAGACCCT ACTAGGTCAA AATaGAtC
Fragment 4A/B
CTaGAGGAGG TGATGCCCCA AGCTGAGAAC CAAGACCCAG ACATC-
GAtCTCCTCC ACTACGGGGT TCGACTCTTG GTTCTGGGTC TGTAG-
AAGGGCATG TtAACg
TTCCGCGTAC AaTTGcagct
Fragment 5A/B
AACTCCCTGG GGGGAGAACCT GAAGACCCTC AGGCTGAGGC TACGG-
TTGAGGGGACC CCCTCTTGGA CATCTGGGAG TCCGACTCCG ATGCC-
CGCTGCATC GATctgca
GCGACAGTAG CTAg
Fragment 6A/B
CGATTTCTTC CCTGTCAAAA CAAGAGCAAG GCCGTGGAGC AGGTG-
TAAAGAAG GGACAGTTTT GTTCTCGTTC CGGCACCTCG TCCAC-
AAGAAcGCgT gcatg
TTCTTgCGcA c
Fragment 7A/B
CGCGTTTTAAT AATAAGCTCC AAGACAAAGG CATCTACAAA GCCAT-
AAATTA TTATTCGAGG TTCTGTTTCC GTAGATGTTT CGGTA-
GAGTGAGTTF GAC
CTCA
Fragment 8A/B
ATCTTCATCA ACTACATAGA AGCCTACATG ACAAT-
CTCAAACTG TAGAAGTAGT TGATGTATCT TCGGATGTAC TGTTA-
GAAGATACGA AACTGA
CTTCTATGCT TTGACTtcga
Fragment 9A/B
(Lower case letters indicate that a base differs from that of the native sequence at the same site)
Example VI
Antibodies Specific for the CENKSKAVE-Peptide
50 mg of ovalbumin (OVA) and 50 mg of myoglobulin (MYO) (e.g. available from Sigma) are each dissolvcd in 10 ml of 0.1 M sodium bicarbonate, and reacted with 1 ml of 0.12 iodoacetamide solution (88 mg of iodoacetamide dissolved in 4 ml 0.1 M sodium bicarbonate) for 1 hour at room temperature in a 15 ml Falcon tube (Falcon Plastics, Oxnard, Calif.), or the like. Each reaction mixture is dialyzed overnight against 4 liters of 0.1 M sodium bicarbonate at 4RC. Separately, 10 mg of CENKSKAVE is dissolved in 2 ml of 0.1 M DTT (dithiotheitol) solution (containing 50 mM Tris and 2.5 mM EDTA at pH8) in a 4 ml tube, incubated at 37° C. overnight; and then applied to a GF05 gel-filtration column (1.5×26.5 cm) (LKB, Bromma, Sweden) and eluted with a peptide elution buffer consisting of 0.015 M acetic acid and 0.005 M beta-mercaptoethanol. Three fractions of about 3.5 ml each which contained the reduced peptide are identified by optical density at 206 nm, collected, pooled, frozen in dry ice, and lyophilized overnight. Meanwhile OVA and MYO are recovered from dialysis, and clarified by filtration through 0.45 micrometer filters. OVA and MYO are activated by mixing each with 380 microliters of N-hydroxysuccinimide ester of iodoacetic acid (NHIA) (disclosed by Rector et al., in J. Immunol. Meth., Vol. 24, pg. 321 (1978)) dissolved in tetrahydrofuran (THF) (5 mg/ml); stirring for 30 minutes at room temperature, and dialyzing overnight against 4 liters PBS (1.8 g NaH 2 PO 4 —H 2 O, 7.2 g Na 2 HPO 4 —H 2 O; and 34g NaCl in 4 liters H 2 O). Separately the lyophilized peptide is resuspended in 5 ml of borate reduction buffer (2 g Na 2 B4O 7-10 H 2 O, 17.4 g NaCl, and 336 mg EDTA-Na 2 in liter H 2 O with pH adjusted to 8.5 with concentrated HCl, deoxygenated under nitrogen for 15 minutes, after which 178 mg ascorbate is added). The dialyzed iodoacetylated OVA and MYO are recovered, separately mixed with equal volumes (preferably 2 ml) of borate reduction buffer containing the peptide, and incubated overnight at room temperature. The resulting conjugates are analyzed by SDS-PAGE (12.5% gel). The conjugate containing solution is diluted with PBS to 1 mg/ml, sterile filtered, and aliquotted to convenient volumes (e.g. 500 microliters) for immunizations, and/or stored at 4° C. Polyclonal anti-sera against the MYO conjugate is produced in both rats and rabbits (New Zealand White). The immunization schedule for rabbits is as follows: Initially (week 0) a 10 ml sample of serum is extracted as a control. One week later (week 1) 0.5 ml of peptide-carrier conjugate is mixed with 0.5 ml Freund's Complete Adjuvant and injected I.P. Three weeks later (week 4) a booster is given consisting of 0.5 ml peptide-carrier conjugate mixed with 0.5 ml Freund's Incomplete Adjuvant. The following week (week 5) an additional booster is given, again consisting of 0.5 ml peptide-carrier conjugate mixed with 0.5 ml Freund's Incomplete Adjuvant, followed by yet another identical booster the next week (week 6). On week 7, 20 ml of serum is bled from the animal. After separating out the cellular fraction the serum assayed for positive anti-CENKSKAVE titer by ELISA. Rat immunization proceed similarly except that the initial injection consists of 0.15 ml PBS and 0.1 ml peptide-carrier conjugate mixed with 0.75 ml Freund's Complete Adjuvant, boosters consisted of 0.15 ml PBS and 0.1 ml peptide-carrier conjugate mixed with 0.75 ml Freund's Incomplete Adjuvant, and only 2-3 ml of serum is bled from the rat. Again, a positive anti-CENKSKAVE reaction is detected by ELISA.
The descriptions of the foregoing embodiments of the invention have been presented for purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention to thereby enable others skilled 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.
Applicants have deposited separate cultures of E. coli MC1061 carrying pcD(SRα)-F115, pH5C, and pH15C, respectively, and hybridoma JES3-19F1.1.1 with the American Type Culture Collection, Rockville, Md., USA (ATCC), under accession numbers 68027, 68191, 68192 and HB10487, respectively. These deposits were made under conditions as provided under ATCC's agreement for Culture Deposit for Patent Purposes, which assures that the deposits will be made available to the US Commissioner of Patents and Trademarks pursuant to 35 USC 122 and 37 CFR 1.14, and will be made available to the public upon issue of a U.S. patent, which requires that the deposits be maintained. Availability of the deposited strain is not to be construed as a license to practice the invention in contravention of the rights granted under the authority of any government in accordance with its patent laws.
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Mammalian genes and proteins, designated cytokine synthesis inhibitory factors (CSIFs now known as Interleukin-10 (IL-10)), are provided which are capable of inhibiting the synthesis of cytokines associated with delayed type hypersensitivity responses, and which, together with antagonists, are useful in treating diseases associated with cytokine imbalances, such as leishmaniasis and other parasitic infections, and certain immune disorders including MHC associated autoimmune diseases caused by excessive production of interferon-γ.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of Ser. No. 09/611,908, filed Jul. 7, 2000, which is a continuation of U.S. application Ser. No. 09/125,754, filed Sep. 29, 1998, abandoned, which is a 371 of International Application Serial No. PCT/EP97/01003, filed Feb. 28, 1997, published as PCT International Publication Number WO 97/32598 on Sep. 12, 1997, the contents of which are incorporated by this reference.
TECHNICAL FIELD
[0002] This invention relates to novel vaccine and pharmaceutical formulations and to their manufacture and use in the treatment of deafness. In particular, the invention relates to the use of the protein known as major peripheral myelin protein zero (abbreviated to MPP, Pzero or Po) in a vaccine. The invention further relates to the use of the protein in diagnostic methods and to a kit for use in carrying out such methods.
BACKGROUND
[0003] There is a high incidence of inner ear diseases such as progressive sensorineural hearing loss, sudden deafness, otosclerosis and Meniere's disease. The etiology of these inner ear diseases remains unclear or unknown. However, evidence now suggests that certain inner ear diseases, including those above, appear to be of autoimmune origin. In patients with inner ear disease, several attempts have been made to identify specific antigens with which circulating antibodies and active lymphocytes react. Antibodies against type II collagen and heat shock protein p70 have been described in patients suffering from idiopathic inner ear disease (e.g. Yoo et al., Science 1982, 217, 1153-1155).
[0004] It is known that the 30,000-M r (30 kDa) protein present in guinea pig inner ear is recognized by autoantibodies in sera from patients with inner ear disease. The 30,000-M r inner ear antigen has been partially purified by chromatography (M Y Cao et al., Mol Cell Biochem. 1995, 146, 157-163). This inner ear antigen has now been sequenced, and partial internal sequences and N-terminal sequence (in total 84 amino acids) of this protein have been obtained. It has been found that the 30 000-M r inner ear protein is the major myelin protein zero (MPP, Pzero, Po). The complete sequence of the bovine, rat, mouse, chick, and human proteins has been determined. Each contains 229 amino acids and a signal peptide of 29 amino acids. Po is highly conserved between species and the interspecific replacement rate of Po between human and guinea pig is very low.
BRIEF SUMMARY OF THE INVENTION
[0005] As a consequence of these findings, it is expected that the Po protein may be an important autoantigen in the pathogenesis of autoimmune disease, and that the Po protein may, therefore, be useful for the diagnosis, treatment or prevention of autoimmune inner ear disease.
[0006] Therefore, in a first aspect, the present invention provides the use of major peripheral myelin protein zero as an autoantigen, and the use of major peripheral myelin protein zero in a vaccine. Suitably, the vaccines of the invention are used for the treatment of autoimmune inner ear diseases, in particular, deafness caused by autoimmune inner ear disease. Preferably, the peripheral myelin protein zero has the sequence shown in SEQ ID NO: 1 or is a derivative or fragment thereof having substantially the same immunological activity.
[0007] Preferably, the major peripheral myelin protein zero is in substantially pure form, that is to say, major peripheral myelin protein zero substantially free of other proteins or materials. By “substantially pure” is meant preferably greater than 60% pure, more preferably over 75% pure, advantageously over 90% pure, for example 95-100% pure.
[0008] In a further aspect, the invention provides a method for the treatment or prophylaxis of autoimmune inner ear disease, in particular, deafness caused by autoimmune inner ear disease, which comprises administering to a host in need thereof a vaccine comprising peripheral myelin protein zero.
[0009] The amount of the protein of the present invention present in each vaccine dose is selected as an amount which induces an immunoprotective response without significant, adverse side effects in typical vaccines. Such amount will vary depending upon which specific immunogen is employed and whether or not the vaccine is adjuvanted. Generally, it is expected that each dose will comprise about 1-1000 mg of protein, preferably about 1-200 mg. An optimal amount for a particular vaccine can be ascertained by standard studies involving observation of antibody titres and other responses in subjects.
[0010] In another aspect, the invention provides for diagnostic use of major peripheral myelin protein zero. In particular, the invention provides an immunoassay for detecting antibodies directed against a Po antigen comprising contacting a biological sample, for example, blood or serum, with a polypetptide under conditions that allow for the formation of an antibody-antigen complex and detecting antibody-antigen complexes comprising said polypeptide, wherein said polypeptide comprises an antigenic determinant of the major peripheral myelin protein zero.
DETAILED DESCRIPTION OF THE INVENTION
[0011] A number of protocols for carrying out immunoassays are known, which may, for example, be based upon competition, or direct reaction, or sandwich assays. Protocols may use solid supports or may be by immunoprecipitation. Immunoassays generally involve the use of labeled antibody or polypeptide. The labels may be, for example, fluorescent, chemiluminescent, radioactive, or dye molecules. A particular aspect of the invention provides a polypeptide comprising an antigenic determinant of the major peripheral myelin protein zero, attached to said substrate.
[0012] Diagnostic kits for use in the present invention can be constructed by packaging the necessary materials, including said polypeptide, optionally on a solid support, in a container with a set of instructions.
[0013] The major peripheral myelin protein zero can be obtained and purified using standard techniques well known to those skilled in the art.
[0014] The following experimental details illustrate the invention.
EXPERIMENTAL
[0015] Sera and tissue extracts. Sera from patients with inner ear disease were the same as previously described. All gave a strong signal with the 30,000-M r inner ear antigen in immunoblots. Sera from normal individuals were taken as negative controls. Inner ear tissues were obtained from 200 g Hartley guinea pigs of both sexes. The inner ear tissues were separated into two different tissue pools during the microdissection. The “total tissue pool” included the organ of Corti, the basilar membrane, the spiral ligament, the stria vascularis, the spiral ganglion and the acoustic nerve in the modiolus, as well as the vestibular organ. The “modiolus pool” consisted of the acoustic nerve and the spiral ganglion. Each of these pools was homogenized by ultrasonication at 20 kHz in 10 volumes of Tris-HCl buffer. The homogenate was centrifuged (8000 g×10 min at 4° C.) and the supernatant was kept as the water soluble fraction. The pellets were resuspended in 10 volumes of buffer containing 10 mM Tris-HCl, 1 mM EDTA, 2.5% (w/v) SDS and 5% (v/v) 2-mercaptoethanol, pH 7.4, and supplemented with the following protease inhibitors: 10 mg/ml antipain, 2 mg/ml pepstatin, 40 mg/ml phenylmethylsulphonyl fluoride, 10 mg/ml chymostatin and 10 mM N-ethylmaleimide. The suspension was centrifuged (8000 g×10 min at 4° C.) and the supernatant was filtered through a 0.22 μm filter to yield the SDS-soluble fraction. The water-soluble and SDS-soluble fractions were boiled for 5 min and the protein concentration was adjusted with the respective buffers to 1 mg/ml. The resulting preparations were stored frozen at −20° C. for further analysis. Extracts from the sciatic nerve were likewise prepared from guinea pigs for comparison with extracts from acoustic nerve. The sciatic nerve was dissected from the guinea pigs and extracted as described above.
[0016] Two-dimensional gel electrophoresis. Two dimensional gel electrophoresis was carried out with modifications in a mini-gel system (BioRad). Protein extracts were diluted 10 times with first-dimension sample buffer (9.5 M urea, 2% (w/v) NP-40, 5% 2-Mercaptoethanol, 1.6% (v/v) Ampholine™ pH 5-7, 0.4% (v/v) Ampholine™ pH 3.5-10 to reduce the concentration of SDS to 0.25%. Protein extracts were loaded onto individual gels. Proteins were visualized with 0.25% Coomassie brilliant blue R-250 or transferred to nitrocellulose membrane for immunoblotting.
[0017] Electrophoresis. Protein extracts were prepared for one dimensional SDS-PAGE by adding an equal volume of sample buffer, containing 10% (v/v/) glycerol. A calibration protein sample (Pharmacia LKB, Uppsala) for molecular weight determination was also prepared. The protein extracts were separated by mini-SDS-PAGE in 0.5 mm-think gels containing 15% (w/v) acrylamide according to the method of Laemmli, Nature 1970, 227, 680-685, or by ultra-thin precast 10% to 15% SDS polyacrylamide gradient gels (43×50×0.45 mm) (Pharmacia) using an automated electrophoresis apparatus (Phast System, Pharmacia). Protein bands were visualized by 0.25% (w/v) Coomassie brilliant blue R-250 staining or transferred to polyvinylidine difluoride (PVDF) membranes—(Millipore Corp., Bedford, Mass.) for immunoblotting.
[0018] Immunoblotting. Following two-dimensional gel electrophoresis or SDS-PAGE, the separated proteins were transferred onto PVDF membranes as described by Towbin et al., Proc. Nat. Acad. Sci. USA 1979, 76, 4350-4356, using a mini Trans-Blot™ cell (BioRad). The efficiency of the transfer was checked by staining the gels following electroelution. The PVDF membrane was dried. The lane of the calibration protein was cut from the transferred membrane and stained with Amido Black (0.1% Amido Black B-10, 45% Methanol and 10% Acetic acid solution) and destained with 25% Methanol and 7% Acetic acid solution. The remaining PVDF membrane was used for the immunoblot.
[0019] The blots were washed with Tris-Buffer Saline (TBS, 20 mM Tris-HCl, 500 mM NaCl, pH 7.5) for 10 min, and incubated for 2 hrs at room temperature with 5% (v/v) non-fat dry milk in TTBS (TBS and 0.5% Tween-20, pH 7.5), followed by 3h of incubation with 1/50 dilution of the test sera in 5% milk at room temperature. The blots were washed twice in TTBS, and incubated again for 2 hrs with a 1/600 dilution of an alkaline phosphatase-conjugated second antibody (rabbit anti-human IgA, IgG, IgM (DAKO, Denmark) in TBS. Finally, the blots were washed twice in TTBS and once in TBS, and developed with a freshly prepared solution of alkaline phosphatase-conjugate substrate (Bio-Rad, Calif.).
[0020] N-terminal amino acid sequence analysis. This was made following separation in an agarose 15% (v/v) acrylamide SDS gel treated to remove free radicals. The protein was transferred to a PVDF membrane (Problott™, Applied Biosystems) in 10 mM Caps, pH 11, 10% (v/v) methanol and an electrophoretic cell (Trans-Blot™, BioRad) at 5 V overnight. Following transfer, the membrane was rinsed in transfer buffer (25 mM Tris, 192 mM glycine, 20% (v/v) methanol, pH 8.3), stained for 2 min in 0.25% (w/v) Coomassie brilliant blue R-250, 40% (v/v) methanol and destained in acetic acid/methanol/H 2 O (1:5:4, by vol). The membrane was then washed in distilled water 5 times and air dried. The part of the membrane corresponding to the 30,000-M r protein bands was used for the N-terminal sequencing by automated Edman degradation on an Applied Biosystems automatic sequencer (models 477A) equipped with a 120 A phenylthiohydantoin-amino-acid analyzer.
[0021] Electroelution of the 30,000-M r inner ear protein for microsequencing and MALDI-TOF mass spectrometry. An agarose-based concentration gel was cast as described. Bands corresponding to the 30,000-M r protein and containing an estimated 50 μg of protein were excised from SDS-PAGE gels and concentrated into an agarose gel as described by Rider et al., Eur J Biochem., 1995, 230, 258-265. The protein spot was excised from the agarose gel and melted in 0.1 M Tris-HCl pH 8.6, 5% (v/v) acetonitrile, 0.2% (w/v) octylglucoside. The protein was digested with trypsin (0.2 μg) at 30° C. overnight. The mixture was frozen at −80° C. for 2h, thawed and centrifuged to remove the precipitated agarose for narrow-bore reverse-phase HPLC. Peak fractions in the HPLC elution profile were monitored by the absorbance at 214 mm, collected manually in Eppendorf tubes and microsequenced as described above. Aliquots of peaks from the HPLC (1 μl) were spotted onto the target strip of the MALDI-TOF mass spectrometer (Finnigan Mat Lasermat 2000), mixed with 1 μl of matrix which was a saturated solution of α-cyano-4-hydroxycinnamic acid in 0.1% (v/v) trifluoroacetic acid/acetronitrile (2:1, v/v) and allowed to air dry. Peptide masses were measured with 20-30 laser shots with the machine calibrated on substance P (mass=1347.6).
[0022] Other methods and reagents. Protein was measured by the method of Bradford. Computer searching for homologous sequences in the SwissProt database was made using the BLAST program. Peptide mass fingerprinting was made in the MOWSE database—see Pappin et al., Curr. Biol., 1993, 3, 327-332.
[0023] RESULTS
[0024] Solubilization and purification of the 30,000-M r protein in SDS-polyacrylamide gels. Inner ear extracts were electrophoresed in ultra-thin precast 10-15% SDS gradient gels using the Phast system and stained with Coomassie blue. Lane 1—sample extracted in Tris buffer without SDS in acoustic nerve and spiral ganglion. Lane 2—total inner ear proteins extracted in SDS sample buffer. Lane 3—sample extracted from the acoustic nerve and spiral ganglion in SDS sample buffer. Several bands including one of 30,000-M r were seen with the “total tissue pool” from inner ear prepared in the presence of SDS. The 30,000-M r band was the only band seen with SDS extracts of the “modiolus pool.” By contrast, no band was seen when the “modiolus pool” was prepared in the absence of SDS, or in the presence of non-ionic detergents such as NP-40 of Triton X-100. This suggested that the protein is hydrophobic and might be associated in vivo with cell membranes. After immunoblotting, the 30,000-M r band was recognized by sera from the patients. In two-dimensional gels, the 30,000-M r protein extracted from the “modiolus pool” was detected as a diffuse spot by Coomassie Bue staining or by immunoblotting. The same data were obtained with the “total tissue pool.” Immunoblotting was carried out as follows: The extract from the acoustic nerve and spiral ganglion was subjected to isoelectric focusing (IEF),then SDS-polyacrylamide gel electrophoresis. The proteins on the two-dimensional gel were transferred onto a nitrocellulose membrane. The blot was subsequently probed with a serum from a patient with inner ear disease. One spot, corresponding to the 30,000-M r inner ear protein was identified by comparison with protein standards.
[0025] Identification of the 30,000-M r by protein microsequencing and peptide mass fingerprinting. The 30,000-M r band from the “modiolus pool” was electroeluted onto a PVDF membrane for N-terminal sequencing by classical automated Edman degradation. Twenty-three amino acids were obtained (Table 1). A protein data bank search showed that these correspond to residues 30 to 52 of the major peripheral myelin protein (MMP, Po). There was an identity score of 98% with human Po, 96% with rat Po, 95% with mouse Po, and 93% with bovine Po. Residues 1-29 of Po correspond to the single peptide. The identity of the 30,000-M r protein as protein Po was confirmed by peptide mass fingerprinting. Protein bands corresponding to the 30,000-M r protein were taken from a one-dimensional gel of the “total tissue pool,” electroeluted and concentrated in our agarose gel-concentration system for digestion with trypsin—Rider et al., Eur J Biochem., 1995, 230, 258-265. The narrowbore reverse-phase HPLC profile of the tryptic digest of the protein was obtained as follows: The 30,000-M r inner ear protein was separated in a 0.5 mm thick one dimensional gel, passed through an agarose concentration gel, melted and digested with trypsin. Peaks eluting from the narrow-bore reverse-phase HPLC were detected at 214 nm. The individual peaks numbered 1-26 were collected by hand in Eppendorf tubes for further analysis. By taking aliquots from peaks in the HPLC for MALDI-TOF mass spectrometry, we were able to obtain some masses of tryptic peptides (Table 1). When these masses were fed into the MOWSE peptide mass fingerprinting database, mouse myelin Po protein precursor (mass=27621 Da) was first hit with a score of 0.778. The score was not 1.0 because two masses could not be matched despite the fact neither of them correspond to trypsin autodigestion fragments. One of these (peak 14) was found to correspond to the N-terminal tryptic heptapeptide which has a theoretical mass of 865 Da (Table 1). This peptide had no match in the database because of the presence of the single peptide. The peptide corresponding to the other mass (1549.9 Da=peak 18, Table 1) was taken for microsequencing. Its sequence corresponds to residues 215-227 of the mouse Po protein precursor with a mutation of Pro-217 to Thr. The discrepancy between the measured mass of 1549.9 and the calculated mass of 1534.8 for the sequence in peak 18 could be explained by the presence of 3-methylhistidine. Microsequencing of peak 26 gave a sequence identical to that present in the mouse Po protein precursor (residues 215-227), in which Pro-217 was conserved. This suggests that the 30,000-M r band contains two forms of the Po protein, one of which has a Pro-217 to Thr mutation. Such a mutation, which could correspond to allelic variation, would not affect the overall charge of the protein and, therefore, the two forms would not be resolved by isoelectric focusing in two-dimensional gels. The position of the peptides described in Table 1 with respect to the sequence of the mouse Po protein precursor is shown in SEQ ID NO: 1. Amino acid sequence of mouse Po precursor protein showing positions of the peptides were analyzed by HPLC/MALDI-TOF mass spectrometry or Edman sequencing. The emboldened numbers correspond to the positions of the tryptic peptides (Table 1). The Edman sequences of guinea pig 30,000-M r antigen are shown in italics.
SEQ ID NO:1 14 ←——————→ MAPGAPSSSP SPILAALLFS SLVLSPALAI VVYTDREIYG I VVYTDREVHG 19 ←—————— 23 ←—————————————————→←—————— AVGSQVTLHC AVGSQVTLHC 20 —————→ ——————→←— SFWSSEWVSD DISFTWRYQP EGGRDAISIF HYAKGQPYID SF 16 ————→ EVGAFKERIQ WVGDPRWKDG STVIHNLDYS DNGTFTCVDK NPPDIVGKTS 6 ←———— QVTLYVFEKV —→ PTRYGVVLGA VIGGTLGVVL LLLLLFYLIR YCWLRRQAAL 26 5 ←————————————→ ←—— QRRLSAMEKG ———→ RFHKSSKDSS KRGRQTPVLY AMLDHSRSTK AASEKKSKGL QTTVLY AMLDHSR 18 GESRKDKK
[0026] Additional Experimental Data. SDS-Page patterns of the inner ear and sciatic nerve extracts. The extracts from the sciatic nerve and the acoustic nerve in the modiolus were co-migrated on SDS-PAGE gel, and stained with Coomassie blue. Lane 1—the extract from the sciatic nerve; Lane 2—the extract from the acoustic nerve and spiral ganglion; a single spot appears in each lane at about 30 kDa.
TABLE 1 Analysis of the 30 000 M r inner ear antigen by Edman degradation and MALDI-TOF mass spectrometry. HPLC peak Mol Mass (Da) Position in mouse No. Measured Theoretical Sequence Po precursor 5 618.5 617.7 GLGESR (SEQ ID NO:2) 239-244 6 686.3 685.8 QAALQR (SEQ ID NO:3) 187-192 14* 865.4 — IVVYTDR (SEQ ID NO:4) 30-36 16 970.8 970.1 IQWVGDPR (SEQ ID NO:5) 99-106 18* 1549.9 — QTTVLYAMLD(H)(Y)SR (SEQ ID NO:6) 215-227 19+ 1608.5 1608.8 GQPYIDEVGAFKER (SEQ ID NO:7) 85-98 20 1325.3 1323.5 GQPYIDEVGAFK (SEQ ID NO:8) 85-96 23+ 1952.8 1952.2 YQPEGGRDAISIFHYAK (SEQ ID NO:9) 68-84 26 1531.5 1530.8 QTPVLYAMLDHSR (SEQ ID NO:10) 215-227 N-Terminus — — IVVYTDREVHGAVGSQVTLHCSF (SEQ ID NO:11) 30-52
[0027] The underlined sequences were obtained by Edman degradation. Measured masses correspond to masses of tryptic peptides in peaks from the HPLC determined by MALDI-TOF mass spectrometry. Their sequences were assigned after feeding all of the measured masses into the MOWSE peptide database. + indicates masses derived from partial cleavages. * indicates “no match” masses. Theoretical masses were calculated from the mouse Po precursor sequence using the computer program “Peptidesort” in the GCG package.
[0028] Generation of EASNHL in Guinea Pigs
[0029] An experimental model of autoimmune sensorineural hearing loss was established by immunizing Hartley guinea pigs with an emulsion of 400 μg/ml of PO-protein antigen in complete Freund's adjuvant. The animals were boosted at three and eight weeks with 50 μg of PO-protein antigen in incomplete Freund's adjuvant. Between 1 and 4 weeks later, serum was taken for Western blot analysis and the animals were killed. The hearing of these animals was tested electrophysiologically by measuring brainstem auditory-evoked potential (BAEP). At various times up to 72 days post immunization, BAEP was recorded on a Nicolet CA-1000 system. In the BAEP study, all of the peak and interpeak latencies were prolonged significantly. The minimal hearing thresholds were elevated slightly. Furthermore, tests for antibodies to PO antigen were performed with their serum. An immunoblot analysis (Western Blot) showed that an antibody from the hearing loss animals specifically reacted with the 30,000 Dalton molecular weight antigen identified as the PO-protein.
[0030] Oral Immunization with Po Antigens in the Guinea Pig Model
[0031] In a second step, we developed immuno-intervention to ameliorate the disease processes leading into deafness by inducing oral tolerance. We used the protocol recently reported by Czerkinsky et al. A single oral administration of 500 μg of PO-antigen coupled to the B subunit of cholera toxin (CTB) can markedly suppress systemic immune responses in naive and in systemically immune Guinea pigs. Both early (2-4 hr) and late (24-48 hr) delayed-type hypersensitivity reactivities were strongly suppressed after feeding a single dose of CTB-conjugated—PO. Serum antibody responses were also decreased, although moderately, after oral administration of CTB-conjugated PO. This strategy of vaccination, based on oral administration of small amounts of PO conjugated to CTB, may find applications for preventing or abrogating hearing loss in humans.
[0032] Radioimmunoassay for Detecting Anti-Po Antibodies in Sera from Affected Individuals
[0033] Solid phase radioimmunoassay to detect antibodies to Po antigens can be developed based upon Tsu and Herzenberg (1980). Microtitre plates are coated with purified polypeptides containing Po epitopes. The coated plates are incubated with either human serum samples from patients with inner ear disease or appropriate controls. During incubation, antibody, if present, is immunologically bound to the solid phase antigen. After removal of the unbound material and washing of the microtitre plates, complexes of human antibody-Po antigen are detected by incubation with 125 I-labeled sheep anti-human immunoglobulin. Unbound labeled antibody is removed by aspiration and the plates are washed. The radioactivity in individual wells is determined: the amount of bound human anti-Po antibody is proportional to the radioactivity in the well.
1
11
1
248
PRT
Guinea Pig
1
Met Ala Pro Gly Ala Pro Ser Ser Ser Pro Ser Pro Ile Leu Ala Ala
1 5 10 15
Leu Leu Phe Ser Ser Leu Val Leu Ser Pro Ala Leu Ala Ile Val Val
20 25 30
Tyr Thr Asp Arg Glu Ile Tyr Gly Ala Val Gly Ser Gln Val Thr Leu
35 40 45
His Cys Ser Phe Trp Ser Ser Glu Trp Val Ser Asp Asp Ile Ser Phe
50 55 60
Thr Trp Arg Tyr Gln Pro Glu Gly Gly Arg Asp Ala Ile Ser Ile Phe
65 70 75 80
His Tyr Ala Lys Gly Gln Pro Tyr Ile Asp Glu Val Gly Ala Phe Lys
85 90 95
Glu Arg Ile Gln Trp Val Gly Asp Pro Arg Trp Lys Asp Gly Ser Thr
100 105 110
Val Ile His Asn Leu Asp Tyr Ser Asp Asn Gly Thr Phe Thr Cys Val
115 120 125
Asp Lys Asn Pro Pro Asp Ile Val Gly Lys Thr Ser Gln Val Thr Leu
130 135 140
Tyr Val Phe Glu Lys Val Pro Thr Arg Tyr Gly Val Val Leu Gly Ala
145 150 155 160
Val Ile Gly Gly Ile Leu Gly Val Val Leu Leu Leu Leu Leu Leu Phe
165 170 175
Tyr Leu Ile Arg Tyr Cys Trp Leu Arg Arg Gln Ala Ala Leu Gln Arg
180 185 190
Arg Leu Ser Ala Met Glu Lys Gly Arg Phe His Lys Ser Ser Lys Asp
195 200 205
Ser Ser Lys Arg Gly Arg Gln Thr Pro Val Leu Tyr Ala Met Leu Asp
210 215 220
His Ser Arg Ser Thr Lys Ala Ala Ser Glu Lys Lys Ser Lys Gly Leu
225 230 235 240
Gly Glu Ser Arg Lys Asp Lys Lys
245
2
6
PRT
Guinea Pig
2
Gly Leu Gly Glu Ser Arg
1 5
3
6
PRT
Guinea Pig
3
Gln Ala Ala Leu Gln Arg
1 5
4
7
PRT
Guinea Pig
4
Ile Val Val Tyr Thr Asp Arg
1 5
5
8
PRT
Guinea Pig
5
Ile Gln Trp Val Gly Asp Pro Arg
1 5
6
14
PRT
Guinea Pig
6
Gln Thr Thr Val Leu Tyr Ala Met Leu Asp His Tyr Ser Arg
1 5 10
7
14
PRT
Guinea Pig
7
Gly Gln Pro Tyr Ile Asp Glu Val Gly Ala Phe Lys Glu Arg
1 5 10
8
12
PRT
Guinea Pig
8
Gly Gln Pro Tyr Ile Asp Glu Val Gly Ala Phe Lys
1 5 10
9
17
PRT
Guinea Pig
9
Tyr Gln Pro Glu Gly Gly Arg Asp Ala Ile Ser Ile Phe His Tyr Ala
1 5 10 15
Lys
10
13
PRT
Guinea Pig
10
Gln Thr Pro Val Leu Tyr Ala Met Leu Asp His Ser Arg
1 5 10
11
23
PRT
Guinea Pig
11
Ile Val Val Tyr Thr Asp Arg Glu Val His Gly Ala Val Gly Ser Gln
1 5 10 15
Val Thr Leu His Cys Ser Phe
20
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The invention provides a method for the treatment of prophylaxis of autoimmune inner ear disease, in particular, deafness caused by autoimmune inner ear disease, which comprises administering to a host in need thereof a vaccine comprising peripheral myelin protein zero. The invention further provides diagnostic methods and kits derived from the protein.
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RELATED APPLICATIONS
This application is a continuation of patent application Ser. No. 09/067,420, filed Apr. 28, 1998, now U.S. Pat. No. 6,173,382 entitled “Dynamic Configuration of Memory Module Using Presence Detect Data”.
This application is also related to U.S. application Ser. No. 09/067,549, filed Apr. 28, 1998, entitled “Address Re-Mapping for Memory Module Using Presence Detect Data” (Docket BU9-97-137); U.S. application Ser. No. 08/598,857, filed Feb. 9, 1996, entitled “High Density SIMM or DIMM with RAS Address Re-Mapping”, Now U.S. Pat. No. 5,926,827 (Docket BU9-95-095); and U.S. application Ser. No. 08/582,010, filed Jan. 2, 1996, entitled “Method and Apparatus for Modifying Signals Received by Memory Cards”, Now U.S. Pat. No. 6,035,370 (Docket BU9-95-057).
FIELD OF THE INVENTION
The invention relates generally to memory modules for computer systems. More particularly, the invention relates to techniques for system level negotiation of an operating mode of a memory module by dynamic control of the presence detect data.
BACKGROUND OF THE INVENTION
Computer memory comes in two basic forms: Random Access Memory (hereinafter RAM) and Read-Only Memory (hereinafter ROM). RAM is generally used by a processor for reading and writing data. RAM memory is volatile typically, meaning that the data stored in the memory is lost when power is removed. ROM is generally used for storing data which will never change, such as the Basic Input/Output System (hereinafter BIOS). ROM memory is non-volatile typically, meaning that the data stored in the memory is not lost even if power is removed from the memory.
Generally, RAM makes up the bulk of the computer system's memory, excluding the computer system's hard-drive, if one exists. RAM typically comes in the form of dynamic RAM (hereinafter DRAM) which requires frequent recharging or refreshing to preserve its contents. Organizationally, data is typically arranged in bytes of 8 data bits. An optional 9th bit, a parity bit, acts as a check on the correctness of the values of the other eight bits.
As computer systems become more advanced, there is an ever increasing demand for DRAM memory capacity. Consequently, DRAM memory is available in module form, in which a plurality of memory chips are placed on a small circuit card, which card then plugs into a memory socket connected to the computer motherboard or memory carrier card. Examples of commercial memory modules are SIMMs (Single In-line Memory Modules) and DIMMs (Dual In-line Memory Modules).
In addition to an ever increasing demand for DRAM capacity, different computer systems may also require different memory operating modes. Present memories are designed with different modes and operational features such as fast page mode (FPM), extended data out (EDO), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), parity and non-parity, error correcting (ECC) and non error correcting, to name a few. Memories also are produced with a variety of performance characteristics such as access speeds, refresh times and so on. Further still, a wide variety of basic memory architectures are available with different device organizations, addressing requirements and logical banks. As a result, some memory modules may or may not have features that are compatible with a particular computer system.
In order to address some of the problems associated with the wide variety of memory chip performance, operational characteristics and compatibility with system requirements, memory modules are being provided with presence detect (PD) data. PD data is stored in a non-volatile memory such as an electrically erasable programmable read-only memory (EEPROM) on the memory module. A typical PD data structure includes 256 eight bit bytes of information. Bytes 0 through 127 are generally locked by the manufacturer, while bytes 128 through 255 are available for system use. Bytes 0-35 are intended to provide an in-depth summary of the memory module architecture, allowable functions and important timing information. PD data can be read in parallel or series form, but serial PD (SPD) is already commonly in use. SPD data is serially accessed by the system memory controller during boot up across a standard serial bus such as an I 2 C™ bus (referred to hereinafter as an I 2 C controller). The system controller then determines whether the memory module is compatible with the system requirements and if it is will complete a normal boot. If the module is not compatible an error message may be issued or other action taken.
It is desired, therefore, to provide a memory module that is more flexible in terms of its compatibility with different computer systems, and particularly that permits the computer system dynamically to negotiate available memory module functions and modes.
SUMMARY OF THE INVENTION
The present invention contemplates, in one embodiment, a memory module comprising: a plurality of memory chips on the module; first logic for configuring the memory module to operate in a selectable mode; second logic for storing initial presence detect (PD) data; and third logic for storing modified PD data that corresponds to a requested mode of operation of the memory module received from a system controller.
The invention also contemplates the methods embodied in the use of such a memory module, and in another embodiment, a method for system control of an intelligent-memory module, including the steps of:
a) reading initial presence detect (PD) data from a non-volatile memory on the memory module;
b) writing modified PD data to a volatile memory based on requested operating mode; and
c) controlling transfer of the modified PD data between the memory module and a system controller based on which memory stores up-to-date PD data.
These and other aspects and advantages of the present invention will be readily understood and appreciated by those skilled in the art from the following detailed description of the preferred embodiments with the best mode contemplated for practicing the invention in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of a memory module for a computer system in accordance with the present invention;
FIG. 2 is a flow chart for a negotiation process at the system level with a memory module using READ/WRITE PD data functions;
FIGS. 3A and 3B are flow charts illustrating another aspect of the invention pertaining to a multiple step negotiation process.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, an embodiment of the invention is illustrated in the environment of a computer system 10 . The computer system 10 can be any computer system that utilizes a memory module having presence detect (PD) data and program able or selectable memory module functions and modes. Personal computer systems, such as an IBM APTIVA® or IBM PC-300™, could be used for the computer system 10 , to name just two of many examples. The computer system includes a system controller 12 , and a system memory controller 14 . In this embodiment, the computer system 10 further includes a module 20 , as will be further described hereinafter. The memory controller 14 provides address, data and bus control signals for interfacing the CPU 12 and the memory module 20 . The memory controller 14 includes logic for addressing, receiving, writing and refreshing data in a plurality of memory chips 22 on the module 20 . As will be apparent from the following exemplary embodiments, however, the memory module 20 may also include logic that interfaces with or otherwise controls various functions relating to addressing and data flow with the memory chips 22 .
In accordance with one aspect of the invention, the memory module 20 is of the type that can be generally categorized as an “intelligent” module, in that the module 20 can operate in a plurality of selectable or programmable modes. The programmable feature of the module 20 is significantly advanced beyond the conventional mode selection criteria available by use of the Mode Register function of conventional memory chips such as synchronous DRAMs (SDRAMs). The memory module 20 can include memory chips such as, for example, SDRAMs with standard Mode Register functions such as, for example, burst type, burst length and CAS Latency. Such chips are used today on memory modules such as, for example, Dual Inline Memory Modules or DIMMs. Other module architectures such as SIMMS could also be used. However, these mode register functions alone do not provide the level of flexibility needed to allow system level control to optimally interface with a number of different memory chip 22 designs and memory module 20 capabilities.
In accordance with one aspect of the invention, the memory module 20 includes a logic circuit 24 . In the embodiment, the logic device 24 is realized in the form of an application specific integrated circuit (ASIC). A suitable device for the ASIC 24 is a gate array ASIC such as TOSHIBA ASIC TC160G. Suitable SDRAM devices 22 are IBM 0316409CT3 available from IBM.
The ASIC 24 includes or communicates with a volatile memory 26 . The volatile memory is used to store modified SPD data fields, as will be further explained herein.
The ASIC 24 further includes a look-up table 28 or comparable data set function that stores information about the programmable features of the memory module 20 . The use of a logic circuit 24 provides the capability to include a number of system level programmable or selectable features or operating modes. For example, the ASIC 24 can be configured to allow the module 20 to operate in several addressing modes. In one embodiment, the ASIC 24 effects an address re-mapping operation. This allows the system controller 12 , for example, to select or request an addressing option that is comparable with a mode available on the memory module 20 . For example, SDRAM memories can include a number of banks of memory arrays. An ASIC can be configured to allow the use of a SDRAM in a system that supports only 2 bank SDRAMs, effecting an address re-mapping function. This example of a programmable or selectable feature for the memory module 20 is more fully described in co-pending U.S. patent application Ser. No. 09/067549 entitled “ADDRESS RE-MAPPING FOR MEMORY MODULE USING PRESENCE DETECT DATA” filed on even date herewith, the entire disclosure of which is fully incorporated herein by reference and which is owned in common by the assignee of the present invention.
Other examples of selectable or programmable modes and functions that can be negotiated and effected using the present invention include, for example, changing from an unbuffered to a buffered or registered mode, and engaging or bypassing FET switches (field effect transistor) to allow a DIMM to be connected or disconnected electrically from a bus.
In order for the system controller 12 to be able to take advantage of programmable modes in the memory module 20 , the system controller 12 must be able to communicate with the module 20 to effect a mode request. In accordance with a significant aspect of the present invention, a technique is provided that allows the system controller 12 to negotiate an operating mode with the memory module 20 .
In the described embodiment, this negotiation is effected by the use of the presence detect function of the memory module 20 .
Memory modules that use SDRAMs typically include a presence detect (PD) function. A non-volatile memory such as an EEPROM is included on the DIMM and stores a PD data field. A typical PD data field includes 256 bytes of information which are further categorized into a number of segments as follows:
BYTE NOS.
DATA
0-35
Module functional and performance
information
36-61
Superset data
62
SPD Revision
63
Checksum for bytes 0-62
64-127
Manufacturer's information
128-255
Reserved for system use
The PD data in bytes 0-35 can be used by a system controller to verify compatibility of the memory module 20 and the system requirements. The PD data can be read in serial or parallel format. Although serial PD data (SPD) is used in the exemplary embodiments herein, those skilled in the art will appreciate that the invention can be used with parallel PD data.
The information contained in bytes 0-127 is generally locked by the manufacturer after completion of the module build and test. This ensures that the data is not corrupted or overwritten at a later time.
In the embodiment of FIG. 1, the system controller 12 accesses SPD data stored in a non-volatile memory 30 . The non-volatile memory 30 may be a separate memory device such as an EEPROM, or may be a memory array that is part of the ASIC logic device 24 . A suitable EEPROM with an integrated I 2 C bus controller (shown separately in the drawing for clarity) is a FAIRCHILD part no. NM24CO3L. The system controller 12 reads the SPD data stored in the non-volatile memory 30 (via a bus 30 b ) by accessing the memory 30 through a standard I 2 C bus controller 32 on the memory module 20 and the system memory controller 14 which includes a corresponding I 2 C controller 14 a. The I 2 C bus 34 is an industry standard serial bus, and the I 2 C bus controller 32 can be, for example, a PHILLIPS part no. PCF8584 controller. The system I 2 C controller 14 a may be located on the system mother board or integrated into the memory controller logic 14 as in FIG. 1 . The system controller 12 accesses the memory controller 14 across a standard bus 44 .
The memory controller 14 communicates with the module 20 via a DATA/ADDRESS AND CONTROL bus 40 . This bus 40 can interface directly with the ASIC circuit 24 as illustrated, or can interface directly with the memory chips 22 , as indicated by the phantom bus 42 . Data flow typically is accomplished directly between the memory controller 14 and the memory chips 22 , however, in some applications the ASIC may be used to modify addresses (e.g. as is done in the above incorporated pending application for address re-mapping), or also for data formatting features such as parity, error correction and so on to name a few examples.
The present invention thus is not limited in terms of how data and control signals are exchanged between the system and the module 20 , but rather more generally to how the system can negotiate an operating mode of the module. Thus, although double ended arrows are used to represent data and control flow between the ASIC 24 and the memory chips 22 , this is intended to be exemplary in nature. Those skilled in the art will appreciate that the particular architecture used will depend on the actual programmable features incorporated into the memory module 20 . In some applications, for example, the ASIC 24 will send address and control signals to the memory chips 22 , but the data will flow directly to the memory controller 14 . The module I 2 C bus controller function can be and often is integrated with the non-volatile memory 30 and/or the ASIC device 24 . In another example, the data, address and control signals will flow directly between the memory controller 14 and the memory chips 22 , but the ASIC will provide other features or controls. Thus, the exact flow of signals will depend on each particular implementation, and the exemplary embodiment of FIG. 1 should not be construed in a limiting sense.
The ASIC 24 also has access to data in the non-volatile memory 30 , via a bus 30 a. This is provided so that the ASIC 24 can, in some applications, be used to re-write the original PD data in the non-volatile memory 30 . Furthermore, in the case where the ASIC device 24 directs PD data to be read from the volatile memory 26 , the appropriate control signal, such as the I 2 C clock, is simply withheld from the non-volatile memory 30 by the ASIC 24 .
It is further noted that the various circuits indicated as discrete functional blocks, such as blocks 26 , 28 , 30 and 32 may be part of the overall ASIC device 24 , as represented by the dashed box 24 a around those components.
The system controller 12 initially obtains the SPD data from the non-volatile memory 30 during boot-up after the computer 10 is powered up. A power on reset (POR) operation occurs which resets the logic in the memory module 20 to ensure that the preset module operation mode is initiated using the initial or original SPD data stored in the non-volatile memory 30 .
It is another aspect of the invention that the system 12 can originate a negotiation of memory module 20 functions or modes “on the fly”, not just during a power on sequence. Although the embodiment described herein is explained in the context of a power on or boot up sequence, this is merely for convenience of explanation, and those skilled in the art will appreciate that the techniques and apparatus described herein allow the system 12 to negotiate a module 20 mode at any time by initiating a new SPD read/write operation.
In order to effect a negotiation between the system 12 and the memory module 20 , it is preferred but not required that the system controller 12 be able to ascertain whether the module 20 includes programmable features. It is contemplated that one of the PD data bytes, such as byte 61 in the address range for “Superset” will be designated to indicate that the memory module 20 has one or more programmable features (such as, for example, address re-mapping). One reason that it may not be required to include programmable information in a PD data byte is that the system 12 can be designed to request a mode change if needed and the logic device 24 could simply accept or reject the request based on the features available on the module 20 . The use of a byte such as byte 61 to indicate programmable features could speed up the negotiation process, particularly where the module 20 does not have programmable features.
Based on an initial PD data from the non-volatile memory 30 , the system controller 12 can compare the module 20 performance and operational features with the system requirements. This comparison can be effected by the system BIOS as is known. If the module 20 is compatible with the system 12 requirements, normal boot up and operation follows. If, however, the module 20 has module or device functions that are inconsistent with the system level requirements, and if the PD data indicates that the module 20 has one or more programmable features, then a negotiation process can be executed by the system 12 . Again, the latter requirement of an affirmative indication in the PD data of programmable features is not required in order to carry out the present invention but is a preferred embodiment.
A negotiation process between the system controller 12 and the module 20 can be implemented as follows. Based on the system requirements, the system controller 12 writes or transfers modified or requested PD data to the module 20 . The modified PD data corresponds with a requested operating mode or function and can be transferred by a complete PD data field write of all 255 bytes, or alternatively the system controller 12 could write data for only the PD data entries that the system controller 12 desires to change. In either case, the modified PD data is generally transmitted to the logic device 24 by the memory, controller 14 and the I 2 C controller 32 . The ASIC logic device 24 stores the modified PD data in the volatile memory 26 . A volatile memory 26 can be used to store the new PD data because when power is removed it will be preferred to effect a start up sequence with the “original” or initial PD data in the EEPROM 30 . Thus, it is further contemplated that for a system level negotiation, modified or requested PD data will not be written to the EEPROM 30 because it is desirable not to lose the original PD data therein. But, alternative techniques for preserving the original PD data while using the non-volatile memory 30 for the modified PD data, and then re-writing the original PD data back to the memory 30 could be implemented if needed, although such a process may not be feasible in some applications.
After receiving the modified or requested PD data from the system controller 12 , the ASIC logic device 24 can compare the new PD data and its corresponding modes or functions, with permitted modes or functions that are supported by the ASIC device 24 . The permitted functions can be obtained, for example, from the look-up table 28 . This process does not require a “translation” per se of PD data to corresponding functions. For example, the ASIC device 24 can be provided with a look up table 28 or other suitable stored data format that indicates PD data values that it can support. The look-up table 28 may also store data that indicates various operational parameters of the memory chips, which data can be used to analyze additional compatibility features that might otherwise not be available from the conventional PD data and mode register functions.
In the case where the modified PD data corresponds to functions supported on the module 20 , the modified or new PD data is saved in the volatile memory 26 and normal start-up and operation continues under the new mode or function. Thereafter, the ASIC logic device controls the transfer of PD data either from the non-volatile memory 30 or the volatile memory 26 depending on which memory holds the most up-to-date PD data for each PD data byte. The volatile memory 26 can be designed to store all the PD data field entries, in which case PD data transfer can occur from the volatile memory 26 alone. Alternatively, the volatile memory 26 can be used to store only the new up-to-date PD data entries, in which case the ASIC device 24 will use both the non-volatile memory 30 and the volatile memory 26 to transfer PD data to the system controller 12 . In the latter case, it is contemplated that the ASIC device 24 will set a “flag” bit for each SPD address that is rewritten by the system 12 . This bit can then be used to direct any future “SPD READ” operations to use the PD data contained in the volatile memory 26 for those addresses.
The system controller 12 may elect to verify that the new mode or function has been entered. In this case, the system performs a READ of the PD data to verify compatible functions are in use. In general, the system controller 12 would then initiate a power on self test (POST) to ensure the memory module 20 is fully functional.
In the event that the module 20 is not programmable or does not have requested programmable functions supported by the ASIC logic device 24 , the system controller 12 will continue the boot up process with appropriate diagnostics or other initialization processes as normally occurs when incompatible memory devices are detected during power up.
With reference to FIG. 2, a suitable control process in accordance with the invention is provided. At step 200 a POR sequence is performed to initialize the memory module 20 . At step 202 the system controller 12 accesses the initial PD data stored in the non-volatile memory 30 . In the described embodiment, step 202 is a serial PD READ operation via the I 2 C bus 34 and I 2 C-controller 32 .
At step 204 the system controller 12 determines whether the initial operating modes and functions of the memory module 20 are compatible with system level requirements. If YES, normal operation continues at step 206 . If NO, the system controller 12 at step 208 writes modified or new PD data to the memory module 2 b, which new PD data is stored in the volatile memory 26 . Shown in dashed lines on FIG. 2 is a related step 208 a for systems wherein a PD data entry is used as a flag or marker to indicate to the system controller 12 whether the module 20 supports programmable functions or modes. If NO, the system enters its normal diagnostic and configuration functions at step 210 under control of the BIOS.
At step 212 the ASIC logic device 24 determines whether the requested function, as indicated by the modified PD data, is supported on the memory module 20 . If YES, the up-to-date PD data is stored (step 214 ) and provided during subsequent READ operations (step 216 ) during normal operation (step 206 ). If the requested function is not supported by the memory module 20 as determined at step 212 , the system enters the normal diagnostic/configuration functions at step 210 , as is the case from step 208 a if the module 20 is not programmable. Note that at step 214 the a requested mode change is also effected. It is at this point, for example, that the system may perform a self-test to verify that the requested change has been implemented.
Those skilled in the art will appreciate that the exemplary embodiment of FIG. 2 illustrates a negotiation process involving a single request step by the system controller 12 . In accordance with another aspect of the invention, the negotiation process can include a number of exchanges between the system 12 and the ASIC 24 in an attempt to find a compatible set of operating parameters. This aspect of the invention assumes that the memory module includes programmable features.
FIGS. 3A and 3B illustrate this aspect of the invention. FIG. 3A shows a suitable process flow for the system 12 and FIG. 3B shows a suitable process flow for the memory module 20 , in particular the ASIC control 24 . Note that the functions identified in FIG. 2 can also be incorporated as required for the alternative embodiment, with FIGS. 3A and 3B illustrating additional and/or alternative steps for carrying out a multiple step negotiation process.
In essence, the system controller 12 makes a number of attempts to find a compatible configuration within the programmable features of the DIMM. This is effected in the FIGS. 3A and 3B embodiment as follows. On the system 12 end (FIG. 3 A), at step 300 the system 12 reads the serial presence detect data from the DIMM, through the bus controller 14 a and the SPD READ/WRITE bus 34 . If at step 302 the SPD data indicates that the memory module 20 is compatible with system requirements, then at step 304 normal boot proceeds. If the result at step 302 is negative, then the system 12 , at step 306 , updates its memory function requirements list and if no further options are available the system 12 will de-allocate and proceed to a diagnostic routine or operate under the final negotiated parameters if permitted. If at step 306 there are additional options, then the system writes at step 308 the next choice of SPD data to the memory module 20 , in a manner, for example, as previously described herein before. After step 308 the system returns to step 300 to verify whether the latest requested SPD data has been successfully accepted by the DIMM.
On the DIMM side, as in FIG. 3B for example, one aspect of this embodiment is that not only does the ASIC 24 analyze the requested SPD data from the system 12 as written to and stored in the volatile memory 26 , but if the requested data is not available the ASIC 24 can modify the data in the memory 26 based on its next available option as identified from its look-up table 28 . The system 12 then reads this latest information (at step 300 in FIG. 3A) to determine if it is compatible. Thus, the negotiation process is dynamically implemented by the ASIC 24 and the system controller 12 . The process flows of FIGS. 3A and 3B thus operate together, although they are illustrated for convenience as separate flow diagrams.
In FIG. 3B then, at step 400 , the ASIC 24 sets the normal DIMM operating mode and permits an SPD read operation by the system 12 . The ASIC 24 then waits for an SPD write operation at step 402 as will be effected by the system 12 from the process of FIG. 3A if the DIMM normal mode is not compatible with the system 12 requirements. If the DIMM can support the SPD request from the system 12 , then at step 404 the program advances to step 406 and the memory module 20 operates under the new SPD parameters. If the result at step 404 is negative, then at step 408 the ASIC 24 writes modified SPD data to the volatile memory 26 and then at step 406 waits for the next SPD read by the system 12 .
Thus the process of FIGS. 3A and 3B can continue until either a compatible set of parameters is negotiated, or until the system 12 and/or the DIMM 20 options (as stored in their respective look-up tables) are exhausted.
As an example of a multiple step negotiation process, a DIMM may have hard programmed operating functions such as a 100 megahertz clock, CL=3 and T ac =5 nanoseconds (“100M/3/5”). The DIMM SPD support list (such as can be stored as part of the look-up table 28 for example) may indicate that the DIMM can accept different modes such as 125M/4/6 (i.e. 125 megahertz clock, CL=4 and T ac =6), 125M/3/6, 100M/4/7, 100M/3/7, 83M/2/8, 66M/1/7 and so forth. On the other hand, the system 12 requirements list may include 100M/2/4.5, 100M/3/6.5, 83M/2/9, 66M/1/12 and so on. Thus the DIMM and system can exercise a multiple step negotiation process by which the ASIC and system scan their respective support lists and write modified PD data in an effort to find a compatible match.
The invention thus provides techniques for system level negotiation with a programmable memory module by using PD READ/WRITE functions.
While the invention has been shown and described with respect to specific embodiments thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiments herein shown and described will be apparent to those skilled in the art within the intended spirit and scope of the invention as set forth in the appended claims.
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A memory module includes a plurality of memory chips on the module; first logic for configuring the memory module to operate in a selectable mode; second logic for storing initial presence detect (PD) data; and third logic for storing modified PD data that corresponds to a requested mode of operation of the memory module received from a system controller. The system checks the first logic to see if the mode is compatible with the system mode. If not, different PD data is written to and read from the third logic successively until a compatible mode is found or the available PD data is exhausted.
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This application is a continuation of application Ser. No. 07/486,745, filed Mar. 6, 1992, now abandoned, which is a continuation of application Ser. No. 07/396,378, filed August 1989, now abandoned.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention generally relates to heat resistant fabrics and yarn for making the same. This invention relates more specifically to a heat resistent cost effective yarn and fabrics made therefrom which are suitable for use in molten metal splash type applications.
It has heretofore been common practice to make heat resistant fabrics from yarns of asbestos fibers. The high heat resistant asbestos fiber offered one of the highest level of resistance to molten metal splashes and was used extensively for minor as well as major molten metal splash applications. More recently, the use of asbestos fibers has been considered hazardous to the user as well as other persons exposed to the fibers.
The fabric and yarn of the present invention do not utilize asbestos fibers but do find utility as substitutes for asbestos yarn and fabric.
Other inventors have attempted to develop asbestos substitute fabrics suitable for minor molten metal splash applications. These prior attempts yielded fabrics which satisfied the application but did not offer the same thermal protection or the cost effectiveness of the present invention.
Although efforts to examine the hazard levels of various molten metal splash applications and to quantify the required fabric performance levels for those applications have advanced development of fabrics for the specified level of performance with respect to minor molten metal splash resistance, there was still a need for a cost effective fabric in the minor molten metal splash application. Presently, the most common fabrics are constructed using ring-spun yarns of Permanently Flame Retardant (PFR) Rayon (Cellulosic) fibers. Additionally, there is some use of fabrics which are comprised of yarns having an aramid wrapping which is spun about a core, however, they are quite expensive for this application.
As can be seen from the above, the art desires a yarn and fabrics which are usable in minor molten metal splash type applications and direct radiant heat at a cost effective level.
The fabric of the invention employs known techniques of manufacturing core spun yarn with a novel fiber mix and distribution of fibers as a means to optimize cost and performance with respect to minor molten metal splash resistance.
It is the principal object of the invention to provide a lightweight fabric, for protecting personnel and equipment, which is cost effective, resistant to high temperatures, thermal shocks and suitable for application in minor molten metal splashes.
Other objects and advantageous features of the invention will be apparent from the descriptions and claims.
SUMMARY OF THE INVENTION
In accordance with the invention, a suitable fabric is provided for protective garments and clothing which are designed mainly to provide protection against radiant heat exposure and minor molten metal splashes. The yarns for the construction of this fabric are made using core-spun yarns having a high temperature and flame resistant central core component of filament fiberglass yarn wrapped with a covering consisting of flame retardant modacrylic fibers. Subsequently, the core-spun yarns are converted into a suitable fabric. In the preferred embodiment, the woven fabric is laminated with a protective metallic foil/film using standard laminating techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part hereof in which:
FIG. 1 is an enlarged view in elevation of a yarn in accordance with the invention, and
FIG. 2 is an enlarged view in perspective of a suitable fabric made from the yarn of FIG. 1.
FIG. 3 depicts a test apparatus for molten metal splash.
FIG. 4 depicts a test apparatus for radiant heat.
FIG. 5 is a graph depicting temperature increase through the fabric vs. time.
FIG. 6 is a graph depicting weight loss vs. temperature.
Like numerals refer to like elements throughout the several view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to FIG. 1 of the drawings, a core-spun yarn 10 is there illustrated which includes a core 11 of multiple filaments and a covering 12 of fibers enclosing the core 11.
The core 11 is preferably of flame and high heat resistant filament fiberglass fibers. One suitable fiberglass core material is available under the trade name Fiberglas from Owens/Corning Fiberglass Company, Toledo, Ohio and another suitable fiberglass material is available from PPG Company, Pittsburgh, Pa.
The core 11 is of fragile fiberglass material with low abrasion resistance and high temperature resistance, softening above 1,300° F. and melting above 2,000° F., with a thermal shock resistance to molten steel on the order of 2850° F.
While the size and the weight of core 11 may be varied, one suitable core is ECDE 150 1/0--1 Z--33 tex Fiberglas yarn from Owens-Corning. In this case, core 11 is a continuous filament yarn containing approximately 408 single filaments with a strand count of 150 and a nominal 0.00025 filament diameter with one Z turn per inch.
The cover 12 is preferably of flame retardant modacrylic fibers, each fiber being individually wrapped around core 11 to form the cylindrical spiral covering 12. One suitable material is available under the trade name Teklan from Courtaulds plc Coventry, Warwickshire England. By way of comparing the covering to the core, it should be noted that Teklan fiber has a softening point of about 374° F. Thus the core softening temperature is about 3.5 times that of covering 12.
Other such suitable fibers for cover 12 are available under the following trademarks, Dynel from Union Carbide Company, SEF fiber from Monsanto Company and Verel from Eastman Company. The covering 12 can also be of a blend of flame retardant modacrylic fibers or of flame retardant modacrylic fibers blended with other fibers. Suitable blends may consists of flame retardant modacrylic and aramid fibers and/or phenolic fibers and/or flame retardant cellulosic fibers and/or polybenzimidazole and/or partially oxidized or fully oxidized PAN fibers.
The size and weight of the covering 12 may be varied in accordance with required yarn weight, however, the core to cover ratio should be about 2 to 3. The covering 12 is applied to the core 11 by individually wrapping the fibers in a cylindrical spiral around the core 11 so that core 11 is completely covered. In the preferred embodiment, the core spun yarn is produced on the Dref Core Spinning Systems available from the Feher Co. of Linz, Austria.
As noted, the proportions of core to covering may be varied as desired. However, in the preferred embodiment, the ratio of filament core to modacrylic fibers is 2 to 3 by weight.
Although the covering 12 is not as resistant to high temperature as the core 11, it does provide a cushion around core 11 to compensate for its fragility and lack of abrasion resistance. Thus, a suitable yarn which is resistant to high temperatures and to thermal shocks is provided for fabrication into a textile fabric.
Referring now to FIG. 2 one suitable textile fabric 15 is illustrated. The textile fabric 15 as shown is a herringbone weave with both warp and filling threads of the yarns 10 heretofore described. The warp threads and filling threads may be of single or plied construction. The weave may be of any desired pattern providing a stable textile fabric. As illustrated, the weave comprises unitary bands 16 and 17 of two up, two down herringbone twill, each of a width of approximately one half inch. The weight of the textile fabric may be varied between 4 to 24 oz. per square yard with the preferred fabrics weighing approximately 14 oz. per square yard. The fabric 15 can be made into protective clothing and maintenance fabrics. The textile fabric 15 has high heat and abrasion resistance, and resistance to thermal shock attendant upon splashing of molten metal.
As also shown in FIG. 2, a metallic lamination 18, preferably of aluminum foil or film, can be provided by vacuum application or by passing the fabric and the film between pressure applying rolls after an adhesive has been applied to the fabric, or in any other desired manner, including spray coating, to increase heat reflection and further enhance the qualities of the fabric.
The cost effectiveness of the present invention may be seen from the following.
Example 1
If one assumes a metallized or aluminized PFR rayon fabric with the weight of 19 oz. per square yard, you will have approximately 17 oz. of substrate fabric with a requirement for about 1.055 pounds of the PFR rayon staple fiber per square yard of substrate fabric. The yarn is a ring spun yarn and the substrate fabric is woven in a herringbone weave. Based on the foregoing, the cost factor for the PFR rayon fabric can be calculated. PFR rayon fiber is commercially available at a cost factor of approximately 3.5 per pound. Since the substrate fabric is comprised entirely of PFR rayon, the cost factor for the staple fibers raw material in one square yard of the PFR rayon substrate fabric is 1.005×3.5 or approximately 3.7.
Example 2
If one now assumes an aluminized or metallized 16 oz. per square yard fabric having a substrates fabric woven from core spun yarns utilizing a fiberglass core and an aramid cover fiber, you will have approximately 14 oz. of substrate fabric. A suitable fiberglass filament, 33 tex yarn is commercially available for a cost factor of approximately 1.75 per pound and aramid cover fiber is available in a cost factor range per pound of about 7.6 to 10.60 or an average of 9.1. Kevlar and Nomex are the trade names for two suitable aramid fibers. Utilizing the preferred ratio of the present invention of 40% central core weight and 60% covering weight, we can calculate the cost factor for the fiberglass core--aramid cover core spun yarn. Using the foregoing fiber contribution for the core spun yarn and the same construction as the substrate fabric of Example 1, the raw material cost factor is (1.75×0.4)+(9.1×0.6)×14/16 or 4.84.
Example 3
Turning to the present invention, if one assumes a 16 oz. square yard aluminized fabric having a substrates fabric of 14 oz. per square yard maybe produced in the same manner and with the same commercially available fiberglass filament as Example 2 but with a covering of modacrylic fiber, substrate cost savings are realized. Modacrylic fiber is available for a cost factor of approximately 1.85 per pound. Based on the cost factors, the raw materials cost for fabric of the present invention in the same construction as Examples 1 and 2 is (1.75×0.4)+(1.85×0.6)×14/16 or approximately 1.58.
Upon exposure to temperatures in the range of 400° F. through 700° F., the fiberglass core aramid fabric, Example 2, will have performance characteristics which are equivalent to those of the invention, Example 3; however, the PFR rayon fabric, Example 1, will not equal those performances. The rayon fabric will exhibit significant thermal shrinkage while the fabric of the present invention will remain virtually unchanged. The rayon fabric will exhibit high weight loss which results in poor thermal stability. By way of distinction, the fabric of the present invention exhibits very low weight loss and high thermal stability.
The experimental method for testing with respect to molten metal splash is illustrated in FIG. 3. The fabric 20 is mounted on transite board 22 and held in place with clips 24 along the upper edge. The fabric is mounted at an angle alpha which is 70° from the horizontal plane H.P. The ladle 26 contains the hot molten metal 28 which is poured from a height of about 12 inches from the fabric. While the ladle 26 has been illustrated with a handle affixed thereto, it is most common to have the ladle mounted in a fixed manner so as to control the distance between the ladle and the fabric.
To summarize, the molten metal splash test, two pounds of iron at a temperature of approximately 2750° F. are poured onto fabric samples which are disposed at an angle of about 70° from the horizontal. The distance between the source of the molten metal and the fabric sample is approximately 12 inches. The preheated ladle is filled with molten iron from the furnace. The metal weight is determined on a spring balance and is maintained at about two pounds. The filled ladle is transferred to a holding or pouring ladle and poured onto the fabric. A delay of fifteen seconds between the furnace pour and the ladle pour is used to ensure the constant temperature of the metal. The results of the tests are assessed by visual examination and heat transfer through the sample.
Still with reference to FIG. 4, heat transfer through the metallized fabric may be sensed by placing a copper disk calorimeter 29 behind the sample. Upon molten metal impact on the surface of the aluminized fabric, the heat energy flows rapidly through the structure of the fabric. The rate of the total heat flow through the fabric depends on various fabric parameters such as the aluminized surface smoothness, type of weave, fabric structure, yarn structure, fiber distribution, thermal resistance of fiber i.e. flame resistance, transition temperature, softening, melting, charring, etc.
In the fabric of Example 3, the above referenced parameters were selected to optimize the fiber, yarn structure and performance levels while minimizing the cost factor of the raw materials.
As noted above, the heat energy upon impact starts to char the modacrylic fiber in the fabric of the invention, at the same time, the temperature rise in the charred modacrylic fibers do not allow a spontaneous combustion in the fabric since the modacrylic fibers used are flame retardant. The flow of heat through the fabric is further restricted by the central core of filament fiberglass which also does not support flame. Subsequently, in about 10 seconds after the impact of molten metal, the charred modacrylic fibers offer additional thermal protection that shows as a slow and steady decrease in temperature rise until 30 seconds after impact when the maximum temperature rise of 41° F. is reached.
By way of comparison, the fabric of Example 1 shows a much higher temperature rise due to the charring of PFR rayon fibers. The flow of heat through the Example 1 fabric is not restricted by a central high heat and flame resistant core. The temperature rise in the first 30 seconds after the impact of molten metal is much higher in the Example 1 fabric. In fact, it reaches the maximum of 93° F.
The above data is graphically depicted in FIG. 5.
In the molten metal splash test, fabrics incorporating yarns according to the present invention out perform fabrics of Example 1 and were equivalent to the performance of Example 2.
With reference to FIG. 4, there is illustrated an apparatus for measuring the heat reflectivity of metallized fabrics in accordance with the principles of military heat reflection test number MIL-C-87076. The test apparatus is comprised of a base 30 on which sample holder 32 is mounted. Sample holder 32 is comprised of two side walls 34 which are mirror images of each other. Each side wall 34 has two vertically disposed slats 36 which define a channel 38. Each of the side walls 34 abuts the front wall 40. The front wall 40 has an aperture 42 in about the center thereof. Quartz lamps 44 are mounted on the outside of front wall 40. The channels 38 are positioned on side walls 34 so that the fabric sample will be positioned at approximately one inch from the quartz lights. The fabric sample 20 is secured in a sample holder 46. The sample is placed directly into sample holder 46 with a piece of blotting paper 48 positioned directly behind the sample 20. Immediately behind the blotting paper 48 is a holder plate 50. Both the sample holder 46 and the holder plate 50 have an aperture 52 in about the center thereof. Apertures 52 are positioned so as to be on line with the aperture 42 in the front wall 40.
In testing, fabric sample 20 is exposed to a radiant heat source which consists of five infrared quartz lamps. The average temperature of the lamps is kept at 2730° F. This temperature is approximately the same temperature as would be found in a steel industry furnace. The sample is placed at the distance of one inch from the radiant heat source. After thirty seconds of exposure, the sample is removed from the sample holder and the degradation of the fabric is assessed by examining the amount of darkening to the blotter paper which was positioned behind the sample.
For high radiant heat exposures of 1500° to 3000 ° F., the metallized fabrics incorporating yarns according to the present invention performed equally with the more expensive core spun aramid yarn of Example 2. Fabrics of the present invention out perform fabrics according to Example 1.
Since many applications do not require the ability to withstand temperatures above 700° F., the use of the core spun aramid yarns represents an excessive cost factor in exchange for unnecessary performance. While the PFR rayon yarns do find applications at these temperatures at a more advantageous cost factor than the core spun aramid yarns, they still represent a more costly alternative to the yarn and fabrics in the present invention.
By way of further comparison of the present invention to the PFR rayon product, reference is made to FIG. 5. If dry samples of the fabrics according to Examples 1 and 3 are exposed to dry hot air temperatures up to 700°, the base fabric of Example 3 will retain substantially more of its fabric weight. The percentage weight loss relates directly to the mass of the base fabric which will be retained and, therefore, available for protection. Such testing may be conducted using thermal gravimetric analysis which will be known to those skilled in the art. With reference to FIG. 5, samples of each of the base fabrics were exposed to temperatures of 400°, 500°, 600° and 700° F. The exposure was for two hours. The weight loss at each temperature was recorded in as percentage weight loss on FIG. 5. As can be seen with reference to FIG. 5, Example 1 exhibited better weight retention than Example 3 at the 400° range. However, at the 500° point, Example 1 exhibited a substantial weight loss when compared to Example 3. In fact, Example 1 exhibited a weight loss between 400° and 500° F. of approximately 60%. At 600° F., Example 3 still retained more than 70% of its weight. By comparison, Example 1 had lost more than 70% of its weight. At 700° F., Example 3 had retained more than 60% of its weight and Example 1 had lost more than 80% of its weight. By way of summary, Example 1 lost approximately 7% at 400° F., 75% at 500° F., 78% at 600° F. and 83% at 700° F. By way of comparison, Example 3, at the same temperatures, had respective weight losses of 18% 20% 28% and 35%. By way of comparing an asbestos base fabric to that of Example 3, asbestos can be expected, depending upon its weight and fiber composition, to exhibit weight losses of between 10 and 30%. Accordingly, Example 3 compares favorably with asbestos at the upper ranges. As demonstrated by FIG. 5, the present invention has substantial benefits over the prior art fabrics in temperature ranges between 400° and 700° F.
As can be seen from the above, the present invention in exposures such as radiant heat, conductive heat, convected heat, flame resistant and minor molten metal splash resistance will perform equally with the fiberglass core aramid fabric and will surpass the PFR rayon fabric. Since the performance characteristics in a given application are essential, a comparison of cost as related to performance becomes important in the evaluation of fabrics.
In the same temperature range of application, the present invention will outperform the PFR rayon material and will have a favorable cost ratio. The present invention is more than two (2) times as cost effective as the PFR rayon (cost factor of 1.58 vs. cost factor of 3.70).
Although the core spun aramid material will withstand higher temperatures, the comparable performance in the same temperature range of application does not justify the additional cost factor. The present invention in the same temperature range of application around 700° F. is more than three (3) times as cost effective as the core spun aramid (cost factor of 1.58 vs. cost factor of 4.84).
As can be seen from the above, the present invention provides an excellent cost effective material for application above 400° F. and up to about: 700° F.
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A heat resistant woven fabric with an optional aluminized backing is disclosed. The fabric is particularly suited for heat resistant garments intended to resist radiant heat and minor molten metal splashes. The fabric comprises of core-spun yarns having a core of flame and high heat resistant filament fiberglass yarn covered by a layer of flame retardant modacrylic fibers, with or without blending with other fibers.
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FIELD OF INVENTION
[0001] The present invention relates to a photovoltaic power circuit, such as a solar cell battery, in particular to a photovoltaic power circuit comprising analog devices, which has a much simpler structure than conventional digital photovoltaic power circuit.
BACKGROUND OF THE INVENTION
[0002] More and more advanced countries are devoting research resources to solar cell batteries, in view of energy crisis. Solar cell batteries belong to the family of photovoltaic power circuits. A photovoltaic power circuit functions by means of the characteristics of semiconductor PN junctions. The PN junctions transfer the received photo energy to electric energy, and charge a battery with the electric energy so that it can generate power. FIG. 1 shows the V-I (voltage-current) relationship for a PN junction diode to generate electric energy, in which the solid line represents the relationship between voltage and current, and the dot line represents the product of voltage and current (V*I), i.e., power. The figure shows only one curve because it is assumed that the received photo energy remains unchanged, If the received photo energy changes, the curve correspondingly changes.
[0003] As shown by the curve in FIG. 1 , the maximum voltage point Voc is at the open circuit point, while the maximum current point Isc is at the short circuit point. However, the maximum power output point is neither at the maximum voltage point nor at the maximum current point, but at a maximum power point MPP, with corresponding optimum voltage Vmpp and optimum current Impp. Because the received photo energy often keeps varying, prior art digital photovoltaic power circuits have to make complicated calculation, by sophisticated digital circuit, to extract the electric energy at the MPP corresponding to the received photo energy.
[0004] An example of such prior art digital photovoltaic power circuit is disclosed in U.S. Pat. No. 6,984,970, which is shown in FIG. 2 in a simplified form. The voltage Vin generated by a photovoltaic device 2 is converted to output voltage Vout by a power stage 3 , to be supplied to a load 4 . The load 4 for example can be a charging battery, and the power stage 3 for example can be a boost converter, a buck converter, an inverter, a fly-back converter, etc. To keep the power stage 3 extracting electric energy at the MPP, a digital controller 5 is provided in the circuit, which includes a digital calculation module 51 (e.g., a digital microcontroller) that keeps multiplying the value of the voltage Vin with the value of the extracted current I to obtain the MPP, and further calculates the optimum voltage Vmpp based on the obtained MPP. The calculated voltage Vmpp is compared with the input voltage Vin, and the comparison result drives a controller circuit 52 to control the power stage 3 . The digital controller 5 shown in FIG. 2 is very sophisticated; it requires a huge number of transistors, and it requires analog-to-digital converters (ADC) to capture voltage and current signals. Inevitably, this increases difficulties and cost of the circuit and its design.
[0005] Another prior art digital photovoltaic power circuit is disclosed in US Patent Publication No. 2006/0164065. This prior art only briefly explains the idea that the circuit includes a search mode and a dithering mode. In the initial search mode, the circuit sweeps the voltage-current curve to find the MPP; thereafter, it enters the dithering mode in which it operates according to the current value corresponding to the MPP, and periodically samples and updates the vale (for details, please refer to paragraphs 0008 , 0010 , 0033 and FIG. 5 of the patent publication). However, this cited patent publication does not explain how it “sweeps” to find the MPP.
[0006] Although there is no detailed circuit structure illustrating how it sweeps, it can be seen from the description relating to the search mode and the sweeping process that this cited patent publication, even if it does not require multiplication of multiple voltage and current values (in fact one can not see how it omits such complicated calculation from the specification of this cited patent publication), requires many digital circuits such as memories or registers and comparators; otherwise it can not select and memorize the maximum power point MPP. In addition to the complexity of the circuit, the sweeping process proposed by this cited patent publication occupies effective operation time of the circuit. Moreover, if light intensity changes after initialization, causing the photovoltaic device to deviate from the original voltage-current curve, the circuit has to reinitiate the search mode with the sweeping process, which is very inefficient.
[0007] In brief, US Patent Publication No. 2006/0164065 requires a complicated circuit and an inefficient process to find the MPP point, so that it can operate in the dithering mode in an analogous manner. Obviously this is disadvantageous.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing, it is desirous, and thus an object of the present invention, to provide an analogue photovoltaic power circuit that improves the drawbacks in prior art.
[0009] To achieve the above and other objects, in one aspect of the present invention, an analog photovoltaic power circuit, comprising: a primary photovoltaic device group for receiving photo energy and generating an input voltage; a power stage for converting the input voltage to an output voltage; an optimum voltage point estimation circuit for estimating an optimum voltage point according to a ratio of the open circuit voltage of the primary photovoltaic device group; and an analog comparison and control circuit for controlling the conversion operation of the power stage according to a comparison between the optimum voltage point estimated by the optimum voltage point estimation circuit and the input voltage.
[0010] In the above-mentioned aspect of the present invention, the ratio is preferably about 70% to about 90% of the open circuit voltage, such as 80%. Because the optimum voltage point is obtained from a ratio of the open circuit voltage of the primary photovoltaic device group, it is not required to use a sophisticated digital calculation circuit, nor any sweeping process.
[0011] In another aspect of the present invention, an analog photovoltaic power circuit comprises: a primary photovoltaic device group for receiving photo energy and generating an input voltage, the input voltage corresponding to an input current; a power stage for converting the input voltage to an output voltage; an optimum voltage point estimation circuit receiving a predetermined voltage and estimating an optimum voltage point according to (1) a direction of variation of the input voltage and a direction of variation of the power generated by the primary photovoltaic device group, or (2) a direction of variation of the input current and a direction of variation of the power generated by the primary photovoltaic device group; and an analog comparison and control circuit for controlling the conversion operation of the power stage according to a comparison between the optimum voltage point estimated by the optimum voltage point estimation circuit and the input voltage.
[0012] In the above-mentioned aspect of the present invention, it is not required to precisely calculate the maximum power point at the initialization stage; the initial value of the optimum voltage point can start from a rough starting point. The rough starting point can be a divisional voltage from a predetermined voltage obtained by a simple voltage divider circuit. The predetermined voltage can be a fixed voltage, or obtained from the primary photovoltaic device group, or obtained from a reference photovoltaic device group, without any sophisticated calculation. Furthermore, it is not required to precisely calculate the power generated by the primary photovoltaic device group, but only required to know the direction of its variation. Hence, a very simple power meter, or a simple power trend meter that only estimates the trend of the power changes (that the power is increasing or decreasing) is sufficient. In some cases, it is sufficient to use even a current sensing circuit, and use the current value sensed by the circuit to represent power.
[0013] In yet another aspect of the present invention, a method for extracting energy from a photovoltaic device group comprises the steps of: providing a reference voltage of about 70% to about 90% of an open circuit voltage of the photovoltaic device group; comparing an output voltage of the photovoltaic device group with the reference voltage, to control the output voltage of the photovoltaic device group substantially at the reference voltage; and extracting energy from the photovoltaic device.
[0014] In still another aspect of the present invention, a method for calculating an optimum voltage point of a photovoltaic device group comprises the steps of: providing a predetermined initial value of a reference voltage; estimating a direction of variation of the output voltage of the photovoltaic device group; estimating a direction of variation of the output power of the photovoltaic device group; comparing the two directions, and increasing the reference voltage when both directions are the same, and decreasing the reference voltage when both directions are opposite; and using the adjusted reference voltage as the optimum voltage point.
[0015] In yet another aspect of the present invention, a method for calculating an optimum voltage point of a photovoltaic device group comprises the steps of: providing a predetermined initial value of a reference voltage; estimating a direction of variation of the output current of the photovoltaic device group; estimating a direction of variation of the output power of the photovoltaic device group; comparing the two directions, and decreasing the reference voltage when both directions are the same, and increasing the reference voltage when both directions are opposite; and using the adjusted reference voltage as the optimum voltage point.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings.
[0017] FIG. 1 shows the voltage-current relationship for a photovoltaic device under the same photo energy.
[0018] FIG. 2 is a schematic circuit diagram showing a prior art photovoltaic power circuit.
[0019] FIG. 3 is a schematic circuit diagram showing a first embodiment according to the present invention.
[0020] FIG. 4 is a schematic circuit diagram showing a second embodiment according to the present invention.
[0021] FIG. 5 is a schematic circuit diagram showing a third embodiment according to the present invention.
[0022] FIG. 6 is a schematic circuit diagram showing a fourth embodiment according to the present invention.
[0023] FIG. 7 is a schematic circuit diagram showing a fifth embodiment according to the present invention.
[0024] FIG. 8 is a schematic circuit diagram showing a sixth embodiment according to the present invention.
[0025] FIG. 9 is a schematic circuit diagram showing a seventh embodiment according to the present invention.
[0026] FIG. 10 is a schematic circuit diagram showing an eighth embodiment according to the present invention.
[0027] FIG. 11 is a schematic circuit diagram showing a ninth embodiment according to the present invention.
[0028] FIG. 12 is a schematic circuit diagram showing a tenth embodiment according to the present invention.
[0029] FIG. 13 is a schematic circuit diagram showing an eleventh embodiment according to the present invention.
[0030] FIG. 14 is a schematic circuit diagram showing a twelfth embodiment according to the present invention.
[0031] FIG. 15 shows an example of a current sensing circuit.
[0032] FIG. 16 is a schematic circuit diagram showing a thirteenth embodiment according to the present invention.
[0033] FIG. 17 is a schematic circuit diagram showing a fourteenth embodiment according to the present invention.
[0034] FIG. 18 is a schematic circuit diagram showing a fifteenth embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] The key feature of the present invention is that it uses analog circuit devices, which are much simpler than the devices in prior art, to calculate the maximum power point MPP in a photovoltaic power circuit. The circuit according to the present invention is thus called “analog photovoltaic power circuit”. However, it should be understood that the term “analog photovoltaic power circuit” only means that the key functions of the circuit are achieved by analog devices; it does not mean that all of the circuit devices are analog devices.
[0036] In general, the optimum voltage Vmpp is about 70% to about 90% of the open circuit voltage Voc. Thus, in the first concept of the present invention, the optimum voltage Vmpp is estimated as about 70% to about 90% of the open circuit voltage Voc of the photovoltaic power circuit.
[0037] Referring to FIG. 3 , it is a schematic circuit diagram showing a first embodiment according to the present invention. In this embodiment, Vmpp is estimated as about BO % of Voc (wherein the number 80% is for illustrative purpose; it can be any number). As shown in the figure, this embodiment includes a primary photovoltaic device group 21 and a reference photovoltaic device group 22 . The primary photovoltaic device group 21 generates electric energy, while the reference photovoltaic device group 22 serves to estimate the optimum voltage Vmpp. The voltage generated by the primary photovoltaic device group 21 is supplied to a power stage 3 as its input voltage yin; the power stage 3 for example can be a boost converter, a buck converter, an inverter, a fly-back converter, etc. The power stage 3 is controlled by an analog comparison and control circuit 50 , to lock Vin at the MPP, and to receive energy from its input terminal, by a manner below.
[0038] The reference photovoltaic device group 22 generates a reference voltage VinREF. Because the reference photovoltaic device group 22 corresponds to a very small load, the reference voltage VinREF is about equal to the open circuit voltage of the reference photovoltaic device group 22 . The reference photovoltaic device group 22 is proportional to the primary photovoltaic device group 21 , that is, the number or size of its devices is so arranged that the open circuit voltage of the reference photovoltaic device group 22 is about equal to, or is a ratio of the open circuit voltage Voc of the primary photovoltaic device group 21 . The resistors R 1 and R 2 divide the reference voltage VinREF so that the voltage at the node VR is about equal to 80% of the open circuit voltage Voc of the primary photovoltaic device group 21 , i.e., the estimated Vmpp.
[0039] Preferably, the voltage at the node VR and the input voltage Vin are compared in the analog comparison and control circuit 50 , and the comparison result controls the power stage 3 to receive energy from its input terminal. When the input voltage Vin is larger than the voltage at the node VR, the power stage 3 extracts more current from its input terminal; when the input voltage Vin is smaller than the voltage at the node VR, the power stage 3 reduces current it extracts from its input terminal. According to the voltage-current curve shown in FIG. 1 , when current increases, the output voltage of the primary photovoltaic device group 21 decreases, that is, the input voltage Vin decreases. On the other hand, when current decreases, the output voltage of the primary photovoltaic device group 21 increases, that is, the input voltage Vin increases. Thus, by mechanism of comparison and feedback control, the input voltage Vin will be locked at the voltage at the node VR, so that the input voltage Vin is at the estimated Vmpp. In this way, the power stage 3 works at its optimum operation point, to receive maximum energy.
[0040] The analog comparison and control circuit 50 can be embodied by a very simple linear regulator, as referring to the second embodiment shown in FIG. 4 . In this embodiment, an analog output from the error amplifier EA controls a power transistor 31 of the power stage 3 . The conduction of the power transistor 31 follows the analog output from the error amplifier EA, and the conduction decides the current to be extracted from the primary photovoltaic device group 21 .
[0041] There is power loss in a linear regulator. To avoid it for better efficiency, the linear regulator can be replaced by a switching regulator, such as, using a PWM (pulse width modulation) circuit in the analog comparison and control circuit 50 . The details of a PWM circuit and how it regulates voltage are not explained here for that they are known by one skilled in this art. It should be noted that the use of a PWM circuit is not the only approach; other modulation circuits such as PFM (pulse frequency modulation) circuit can be used in the analog comparison and control circuit 50 .
[0042] As an example, please refer to FIG. 5 , which is the third embodiment according to the present invention. In this embodiment, the analog comparison and control circuit 50 includes an error amplifier EA, which receives the voltage at the node VR as its reference voltage, and receives the voltage Vin as the feedback voltage (maybe better phrased as “feed-forward” voltage), and compares them with each other. The result of comparison is inputted to a comparator CMP, to be compared with a sawtooth wave. A logic circuit receives the output from the comparator CMP, to generate a signal to be used for controlling the power stage 3 .
[0043] It should be noted that the above-mentioned is only one possible arrangement; there are other arrangements to achieve the same or similar purpose. The key point is to control the power stage 3 to extract energy according to the comparison between the voltage at the node VR and the input voltage Vin, in which the voltage at the node VR (about equal to Vmpp) can be obtained by a simple voltage division circuit, without complicated digital calculation module.
[0044] Under the above teaching, those skilled in this art can readily think of many variations. For example, the resistors R 1 and R 2 can be replaced by other devices having suitable DC resistances. Moreover, if the number of diodes connected in series in the reference photovoltaic device group 22 is arranged to be around 70%-90% of the number of diodes connected in series in the primary photovoltaic device group 21 , the resistors R 1 and R 2 even can be omitted. All such variations should fall within the scope of the present invention.
[0045] In the embodiment of FIG. 5 , the energy generated by the reference photovoltaic device group 22 is unutilized because it is not supplied to the load 4 . If it is desired to fully utilize the energy generated by every photovoltaic device, under the spirit of the present invention, the circuit can be modified as below. FIG. 6 is a schematic circuit diagram showing a fourth embodiment according to the present invention. In this embodiment, all photovoltaic devices are productive (hence, the circuit only includes the primary photovoltaic device group 21 , without the reference photovoltaic device group 22 ). On the one hand, the primary photovoltaic device group 21 generates the input voltage Vin; on the other hand, it is electrically connected to ground via a diode DR and a capacitor CR. The voltage across the capacitor CR is the reference voltage VinREF. When the power stage 3 is not active, the right side of the input voltage node Vin is equivalent to an open circuit; the input voltage Vin is equal to the open circuit voltage Voc of the primary photovoltaic device group 21 , and the reference voltage VinREF is equal to the open circuit voltage Voc minus the voltage across the diode DR. This voltage charges the capacitor CR and becomes the voltage across the capacitor CR. Similar to the previous embodiments, by properly arranging the resistances of the resistors R 1 and R 2 , the voltage at the node VR is equal to about 80% of the open circuit voltage Voc, i.e., about Vmpp. The diode DR can be a normal diode, a Shocky diode, or other diode devices.
[0046] In the above-described circuit, when the power stage 3 is active in extracting energy, the right side of the input voltage node Vin is not an open circuit. If the circuit keeps operating in such condition, the input voltage Vin will no more be equal to the open circuit voltage Voc of the primary photovoltaic device group 21 . When the capacitor CR gradually discharges, or when the photo energy received by the primary photovoltaic device group 21 varies, the voltage at the node VR inputting to the error amplifier EA will be inaccurate, deviating from Vmpp. Therefore, although the above-described circuit is able to provide the basic function, it is preferred to periodically turn off the power stage 3 so that the right side of the input voltage node Vin is equivalent to an open circuit, and that the capacitor CR can be charged. To periodically charge the capacitor CR can be viewed as an analog calibration process to calibrate the voltage at the node VR so that it is equal to Vmpp. To this end, a circuit embodiment is shown in the figure. The logic circuit 53 has an enable input EN, which receives a signal ENPWM having a waveform as shown in the figure. Most of the time the signal ENPWM enables the logic circuit 53 (L 1 ), but it periodically disables the logic circuit 53 to turn off the power stage 3 , so that the capacitor CR can be charged. In practical application, the period L 1 can last for several to several tens of seconds, while the period L 2 is in the order of milliseconds. The foregoing approach to indirectly turn off the power stage 3 by controlling the logic circuit 53 , is only one among many possible approaches. For example, to provide a switch at the right side of the input voltage node Vin, is an alternative. The key point is to periodically turn off the power stage 3 so that the right side of the input voltage node Vin is an open circuit, and that the capacitor CR can be charged. All variations achieving such purpose should fall within the scope of the present invention.
[0047] In the embodiment shown in FIG. 6 , because the diode only provides one-way conduction, if light intensity decreases drastically, the voltage on the capacitor CR might not follow instantly, affecting the accuracy of the voltage VR. To solve this, as shown in the fifth embodiment of FIG. 7 , a switch SW operating in an opposite phase to the signal ENPWM is provided at the left side of the input voltage node Vin (the switch SW may be, e.g., a PMOSFET switch, or an NMOSFET switch operated by an inverted signal of ENPWM). When the power stage is turned off (period L 2 ), the switch SW is ON so that the primary photovoltaic device group 21 can charge the capacitor CR; when the power stage 3 is extracting energy, the switch SW is OFF so that the primary photovoltaic device group 21 only provides voltage to the input voltage node Vin, but does not charge the capacitor CR. Thus, the voltage on the capacitor CR can be kept very close to the open circuit voltage Voc of the primary photovoltaic device group 21 .
[0048] In all of the above-mentioned embodiments, to be precise, when the right side of the input voltage node Vin is open circuit, the primary photovoltaic device group 21 is not in a complete open circuit status, that is, the input voltage Vin is not precisely equal to the open circuit voltage Voc. There is a small amount of load current flowing through the path from the primary photovoltaic device group 21 -Vin-DR or SW-VinREF-R 1 -R 2 to ground. Hence, if it is desired to obtained a precise open circuit voltage Voc, and to maintain the voltage on the capacitor CR longer so that the capacitor charging frequency can be reduced, a unit gain circuit can be provided in said path to ensure open circuit status, as shown in the two embodiments of FIGS. 8 and 9 . In the sixth embodiment of FIG. 8 , because the diode DR only provides one-way conduction, a weak current source of low current amount is provided so that the capacitor CR can be discharged. In the seventh embodiment of FIG. 9 , because the switch SW provides bi-directional conduction, a current source is not required. The other parts of these two embodiments are similar to those of FIGS. 6 and 7 , and the details thereof are not redundantly repeated here.
[0049] The above-mentioned embodiments are based on an estimation of Vmpp as 70% to 90% of the open circuit voltage Voc. Under the second concept of the present invention, Vmpp can be estimated more accurately.
[0050] FIG. 10 shows the eighth embodiment according to the present invention. In this and following embodiments, the analog comparison and control circuit 50 is shown as a simple block without showing its details, for simplicity of the drawings. The reference voltage VinREF in this embodiment can be extracted from the output of the primary photovoltaic device group 21 , or the output of a reference photovoltaic device group (not shown), or a predetermined constant voltage. A fixed resistor R 3 and a variable resistor R 4 form a variable voltage divider circuit which divides the reference voltage VinREF to determine the voltage at the node VR; in other words, the resistance of the variable resistor R 4 determines the voltage at the node VR, making it equal to Vmpp. It should be noted that the variable resistor R 4 is only one among many usable devices; any other device with variable resistance, even if its resistance does not vary linearly, can be used for the purpose of the present invention, such as a MOSFET, a JFET, a pinch-resistor, etc. The key point is to adjust the voltage at the node VR by the variable voltage divider circuit; any arrangement serving this purpose meets the requirement of the present invention.
[0051] The resistance of the variable resistor R 4 is controlled by a variable resistor control circuit 7 in a manner as follows. Referring to FIG. 1 , at the left side of the MPP on the V-I curve, when voltage decreases, power increases, with opposite slope directions; at the right side of the MPP on the V-I curve, when voltage increases, power increases, with the same slope directions. Thus, by a comparison between the slope direction of the output voltage of the primary photovoltaic device group 21 and the slope direction of the output power, it can be decided as to where the present V-I relationship stands, i.e., at the left side or right side of the MPP. The resistance of the variable resistor R 4 can be adjusted accordingly to move the voltage at the node VR towards Vmpp. Under this concept, in the circuit of FIG. 10 , a direction comparison circuit 60 is provided, which receives the input voltage Vin (corresponding to the output voltage of the primary photovoltaic device group 21 ) and the power at the output terminal (corresponding to the output power of the primary photovoltaic device group 21 ), and compares their slope directions. The comparison result is sent to the variable resistor control circuit 7 for adjusting the resistance of the variable resistor R 4 .
[0052] To adjust the voltage VR by means of a variable resistor control circuit 7 controlling the resistance of a variable resistor R 4 , is only an illustrative embodiment to show the concept. The spirit is to provide a circuit for adjusting the voltage VR according to a comparison between slope directions of voltage and power. When the slope directions are opposite to each other, the circuit decreases the voltage VR; when the slope directions are the same to each other, the circuit increases the voltage VR. Any variation under this spirit falls within the scope of the present invention.
[0053] There are many ways to embody the direction comparison circuit 60 , one of which is shown in the figure as an example. A power meter 40 at the right side of the figure measures the power at the output terminal (corresponding to the output power of the primary photovoltaic device group 21 ), and sends the measured result to a differential circuit (D. Ckt.) 62 ; the output of the derivative circuit 62 represents the slope of the power at the output terminal. On the other hand, another differential circuit (D. Ckt.) 61 receives the input voltage Vin and generates an output representing the slope of the input voltage Vin (corresponding to the slope of the output voltage of the primary photovoltaic device group 21 ). A slope direction comparison circuit (Slope Direct. Comp. Ckt.) 63 receives the outputs from the circuits 61 and 62 , and compare the directions of the two slopes. The comparison result is sent to the variable resistor control circuit 7 for adjusting the resistance of the variable resistor R 4 .
[0054] The ninth embodiment shown in FIG. 11 shows an example of detailed structure of the direction comparison circuit 60 . It includes operational amplifiers OP 1 and OP 2 , and comparators CP 1 and CP 2 . The comparators CP 1 and CP 2 respectively compare the outputs of the operational amplifiers OP 1 and OP 2 with the voltage stored in the capacitors C 1 and C 2 at a previous time point, and determine the slope directions. The output of the exclusive OR gate XOR indicates whether the slope directions are the same or opposite. It should be noted here that what FIG. 11 shows is only one example among many possible arrangements, which is not intended to limit the scope of the present invention. For instance, the differential circuits 61 and 62 in FIGS. 10 and 11 can be replaced by other high pass filter circuits to obtain the same effect. This is because, under the concept of the present invention, it is not required to obtain accurate values of the slopes, but instead only the slope directions of the output voltage and the output power of the primary photovoltaic device group 21 . As another example, the function of the comparators CP 1 and CP 2 is to transfer the outputs of the operational amplifiers OP 1 and OP 2 to digital signals for inputting into the exclusive OR gate XOR. If the operational amplifiers OP 1 and OP 2 are designed so that their outputs can be distinguished and recognized by a logic operation circuit, the slope direction comparison circuit 63 does not have to include the comparators CP 1 and CP 2 ; the outputs of the operational amplifiers OP 1 and OP 2 can be compared with each other directly.
[0055] FIGS. 12 and 13 show two examples of the detailed structure of the variable resistor control circuit 7 , which are the tenth and eleventh embodiments of the present invention. Again, these two embodiments are illustrative rather than limiting. In details, in the embodiment shown in FIG. 12 , when the output of the direction comparison circuit 60 is low, the upper PMOS switch is ON, so that the capacitor C 7 is charged along a positive direction and adjust the variable resistor R 4 corresponding to the positive direction; when the output of the direction comparison circuit 60 is high, the lower NMOS switch is ON, so that the capacitor C 7 is charged along a negative direction and adjust the variable resistor R 4 corresponding to the negative direction. The foregoing “positive” and “negative” directions, the types and locations of the PMOS and NMOS transistors, and the adjusted directions of the variable resistor R 4 , can be arranged according to the design of the direction comparison circuit 60 . For example, if the exclusive OR gate XOR is replaced by an exclusive NOR gate XNOR, then opposite signals and devices should be used.
[0056] The embodiment of FIG. 13 includes a transconductor GM which generates current corresponding to the comparison between the output of the direction comparison circuit 60 and a reference voltage VB, to charge the variable resistor R 4 for controlling the variable resistor R 4 . The reference voltage VB can be set at a value between the high level and low level of the output of the direction comparison circuit 60 , so that, when the output of the direction comparison circuit 60 is low, the transconductor GM generates positive current to charge the capacitor C 7 along a positive direction and adjust the variable resistor R 4 corresponding to the positive direction; when the output of the direction comparison circuit 60 is high, the transconductor GM generates negative current to charge the capacitor C 7 along a negative direction and adjust the variable resistor R 4 corresponding to the negative direction. Similar to the previous embodiment, the “positive” and “negative” directions (the positive and negative inputs of the transconductor GM) can be arranged according to the output types of the direction comparison circuit 60 , i.e., they may be reversed if needed.
[0057] Referring to FIG. 1 again, according to the present invention, besides determining MPP based on the voltage-power relationship, it is also possible to determine MPP based on the current-power relationship. At the left side of the MPP on the V-I curve, when current increases, power increases, with the same slope directions; at the right side of the MPP on the V-I curve, when current increases, power decreases, with opposite slope directions. Thus, by a comparison between the slope direction of the output current of the primary photovoltaic device group 21 and the slope direction of the output power, it can be decided as to where the present V-I relationship stands, i.e., at the left side or right side of the MPP. FIG. 14 shows the twelfth embodiment of the present invention to embody this concept.
[0058] In the embodiment shown in FIG. 14 , a current sensing circuit 8 senses the input current Tin (the output current of the primary photovoltaic device group 21 ), which is compared with the output of the power meter 40 (the output power of the primary photovoltaic device group 21 ) in the direction comparison circuit 60 . The resistance of the variable resistor R 4 is adjusted according to the result of comparison, to move the voltage at the node VR towards Vmpp. Apparently, because the relationship between current and power slope directions is opposite to the relationship between voltage and power slope directions, the detailed structure of the direction comparison circuit 60 or the variable resistor control circuit 7 should be designed based on such fact. For example, if a circuit shown in any of FIGS. 11-13 is used, an inverter gate should be added at a proper location, or an exclusive NOR gate XNOR should be used instead of the exclusive OR gate XOR, or the locations of the PMOS and NMOS transistors in FIG. 12 should be interchanged, or the positive and negative inputs of the transconductor GM should be interchanged, etc.
[0059] The same as above, to adjust the voltage VR by means of a variable resistor control circuit 7 controlling the resistance of a variable resistor R 4 , is only an illustrative embodiment to show the concept. The spirit is to provide a circuit for adjusting the voltage VR according to a comparison between slope directions of current and power. When the slope directions are opposite to each other, the circuit decreases the voltage VR; when the slope directions are the same to each other, the circuit increases the voltage VR. Any variation under this spirit falls within the scope of the present invention.
[0060] There are many ways to embody the current sensing circuit 8 , one of which is shown in FIG. 15 . The circuit shown in FIG. 15 senses the current Iin and transfers it to a voltage signal to be sent to the direction comparison circuit 60 . Again, this embodiment is for illustration, not for limitation.
[0061] A power meter 40 is used in the embodiments of FIGS. 10 , 11 and 14 . From a first sight, the use of a power meter complicates the circuit, because a power meter needs to measure and calculate product of current and voltage values. Actually, under the concept of the present invention, it does not require an accurate measurement of power, and thus it does not require a sophisticated power meter. What is required is only to know the direction of changes of the output power of the primary photovoltaic device group 21 ; therefore, it is sufficient to use a very simple power meter (as described later with reference to FIGS. 17 and 18 ), or even without a power meter. FIG. 16 shows the thirteenth embodiment of the present invention, which is a variation based on the embodiment of FIG. 14 . As shown at the right side of the figure, since the load 4 is a battery inmost cases, and the voltage of a battery changes very slowly, the power meter 40 can be replaced by a current sensing circuit 41 which only measures the current flowing to the load 4 , and transfers the sensed result to a voltage signal to be inputted to the differential circuit 62 . Thus, the same purpose as that of the circuit shown in FIG. 14 can be achieved. An example of the detailed structure of the current sensing circuit 41 is shown in FIG. 15 . Likely, the right side of FIG. 10 or FIG. 11 can be replaced by a current sensing circuit in a similar fashion.
[0062] If it is desired to take the voltage variation of the load 4 into consideration, we can use a “power trend meter” having a much simpler structure, instead of a power meter. A power trend meter compares the power at the present time point with the power at a previous time point, and generates a signal corresponding to the comparison result. It should be emphasized that the power trend meter only needs to show the direction of power changes, which does not even need to be proportional to the actual power changes. An example of such power trend meter is shown in FIG. 17 as the fourteenth embodiment of the present invention, wherein the power trend is estimated by sensing the heat of a resistor. As shown in the figure, a bipolar transistor Q BP is used to sense the heat variation on a resistor Rs. In general, the base to emitter voltage variation (dV BE ) of a bipolar transistor corresponds to temperature variation (dT) as:
[0000] dV BE /dT≈− 2 mV/° C.
[0000] Thus, the voltage variation can be used to represent the power trend. However, it should be noted that this is an inverted analog signal and should be processed accordingly.
[0063] If it is desired to detect the actual current and voltage, that is, if it is not desired to simply measure the power trend, the fifteenth embodiment of the present invention shown in FIG. 18 provides a simple solution. Please refer to FIG. 11 in conjunction with FIG. 18 , the circuit of FIG. 18 includes the power meter 40 , the differential circuit 61 , and the comparator CP 2 . The output signal PRFI indicates the power changing direction, i.e., the plus or minus sign of d(V*I)/dt, in which d(V*I) is the power change, and dt is the time change. PRFI is a digital signal which can be sent to the exclusive OR gate XOR in FIG. 11 for a logic operation with the output from the comparator CP 1 , to generate a control signal for controlling the variable resistor control circuit 7 . As shown in FIG. 18 , although the circuit detects current and voltage, no complicated multiplication is required, so the circuit is much simpler than a typical power meter.
[0064] In summary, in order to obtain precise MPP, prior art circuits requires complicated digital calculation circuits to calculate precise current and voltage values, which requires transistors in the number of several tens of thousands; however, the analog circuit according to the present invention only requires less than one thousandth of transistors in number as compared with prior art. Thus, the present invention is apparently much more advantageous than prior art.
[0065] The spirit of the present invention has been explained in the foregoing with reference to the preferred embodiments, but it should be noted that the above is only for illustrative purpose, to help those skilled in this art to understand the present invention, not for limiting the scope of the present invention. Within the same spirit, various modifications and variations can be made by those skilled in this art. For example, additional devices may be interposed between any two devices shown in the drawings, such as a delay circuit, a switch, or a resistor, without affecting the primary function of the circuit. In view of the foregoing, it is intended that the present invention cover all such modifications and variations, which should interpreted to fall within the scope of the following claims and their equivalents.
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The present invention discloses an analog photovoltaic power circuit, comprising: a photovoltaic device group for receiving photo energy to generate an input voltage; a power stage circuit for converting the input voltage to an output voltage; an optimum voltage estimation circuit for receiving a predetermined voltage and estimating an optimum voltage according to a direction of variation of the input voltage and a direction of variation of the power generated by the photovoltaic device group; and an analog comparison and control circuit for comparing the optimum voltage with the input voltage, to thereby control the operation of the power stage circuit.
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BACKGROUND OF THE INVENTION
The present invention relates to a railcar for renovating railways and more precisely to a railcar comprising an operating unit equipped for the execution, in sequence, of the following operative steps: removal of the old tracks, removal of the old track supporting sleepers, remaking of the laying plane of the new sleepers, laying of new sleepers; and wherein said operating unit is provided with supporting means to allow its advancement on the old sleepers already stripped of their tracks.
Railcars of the specified type have been hitherto produced, intended to operate continuously for the total renovation of the railway, i.e. for the total replacement of the old track supporting sleepers, the total remaking of their laying plane, the laying on said plane of new sleepers and the successive remaking of the ballast by means of the deposition of new rubble and/or of regenerated rubble in the spaces comprised between the new sleepers.
For this purpose, currently known renovation railcars are mostly equipped with means for removing the old sleepers capable of systematically removing them from the ballast and of depositing them on conveyors which transfer them to an accumulation area on board the railcar, with one or more plowshares for removing the displaced rubble and for levelling the laying plane and with elements, generally acting by gravity, for laying, regularly spaced, the new sleepers on the previously levelled laying plane.
With known railcars of the specified type it is therefore not possible to execute interventions for maintenance or revision entailing the partial and occasional replacement of the sleepers in the section involved, and on the other hand such partial interventions are often sufficient to restore the original efficiency and safety of the track with markedly lower costs.
The inadequacy of known railcars for partially renovating tracks essentially derives from the fact that the current systems for stripping the old sleepers are incapable of extracting them from their related original seats without damaging the laying plane of said seats, so that the laying of the new sleepers entails the complete remaking of said plane.
SUMMARY OF THE INVENTION
The aim of the present invention is to eliminate these disadvantages by providing a railcar capable of performing the total or partial renovation of railways, in particular the partial or occasional replacement of old sleepers with new sleepers having structural and geometrical characteristics similar to or different from the old ones, for example the partial replacement of old wood sleepers with new sleepers in concrete mix.
Within this aim, a particular object of the present invention is to provide a railcar for renovating railways, which is provided with means for the removal of the old sleepers capable of removing them without damaging the laying plane of the original containment seat.
Another particular object of the present invention is to provide a railcar for renovaing railways, which is provided with means adapted to regenerate the original seats of the old sleepers to allow the correct and levelled laying of the new ones and their locking by refilling with rubble.
In particular the regeneration of the original seats is aimed at preventing the new sleepers from being subjected, after laying and securing, to settlement or yieldings different from those of the old sleepers left in use, this allowing the correct longitudinal path of the regenerated track.
A further important object of the present invention is to provide a railcar the operating means whereof, though they perform partial replacement interventions as specified, allow the continuous advancement of the railcar, avoiding thereby idle wait times and delays due to the stopping decelerations and to the starting accelerations of the railcar itself.
This aim, and these objects and others which will become apparent from the following detailed description, are achieved by a railcar for renovating railways comprising an operating unit provided with equipment for removing the old tracks and with supporting elements for advancing on the old sleepers stripped of their tracks, characterized in that it comprises in sequence: first grip means, capable of executing controlled cyclic oscillatory and vertical movements for gripping the old sleepers, removing them from their original seat and laying them on a removal conveyor; a rotary operating element, capable of executing controlled cyclic oscillatory and vertical and horizontal movements for preparing each seat stripped of its related old sleeper; at least one strike element, susceptible to longitudinal and cyclic motion with respect to the frame of the operating unit and subject to fluid actuated displacing and loading means for compacting the new laying plane in each prepared seat and for shaping said seat; second grip means, capable of executing controlled cyclic oscillatory and vertical movements for gripping the new sleepers from a feeder conveyor and for controllably resting them on the laying plane of each new shaped and compacted seat, and strike means also capable of executing controlled longitudinal and vertical movements for packing rubble for filling and final securing, fed into the spaces comprised between the walls of the new seat and the new laid sleeper.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the present invention will become apparent from the following detailed description and with reference to the accompanying drawings, given only by way of non-limitative example, wherein:
FIG. 1 is a lateral elevation view of the operating unit of a renovation railcar according to the present invention,
FIG. 2 is a detail view to an enlarged scale of FIG. 1,
FIG. 3 is an enlarged scale cross section view taken along the line III--III of FIG. 2,
FIG. 4 is a schematic sectional view illustrating the terminal arrangement of the new sleepers in the respective new containment seats,
FIG. 5 is a detailed elevation view showing the first grip means for the removal of the old sleepers, according to another aspect of the invention;
FIG. 6 is an elevation view showing a rotating operating element and a strike element combined into a single operating unit, according to still another aspect of the invention;
FIG. 7 is a sectional view taken along the line VII--VII of FIG. 6,
FIG. 8 is an elevation view showing second grip means for laying the new sleepers, according to a further aspect of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The railcar for renovating railways according to the invention comprises an operating unit 10 according to FIG. 1, intended to advance while operating, in the direction of the arrow F, and which is generally preceded by a certain number of storage rail cars (not illustrated) adapted to receive the old removed materials and to carry the new ones to be laid and which can be followed by other per se known operating units, for example for laying and bolting the new tracks.
The operating unit 10 comprises a carriage defined by a first 11 and by a second 12 frame, mutually connected in a per se known manner by means of a connecting articulation 13.
The frame 11 comprises a first axle 14 the wheels whereof rest on the old tracks 15, as yet not removed, and a second axle 16 cooperating with support means generally indicated at 17-18 and 19. Their structure and operating modes for guiding and advancing the carriage on the railway, already stripped of its old tracks, are described in detail in the U.S. Pat. No. 4,643,100 filed by this same Applicant.
It should be noted that the use of the support means 17-18-19, though advantageous, is not limitative for the present invention, since said means may be replaced with other known support means such as tracked shoes and the like.
Known roller clamps 20 are arranged between the axles 14 and 16, and are adapted to lift the tracks 15 to be removed off the old sleepers T v ; a power generator unit W is arranged ahead of the axle 14 and drives a central hydraulic unit and an electric generator.
Upwardly, the frame 11 bears a conveyor 21 leading to a magazine 22 for the old removed sleepers, and also bears a magazine 23 and a conveyor 24 of new sleepers to be laid and a portal conveyor 25 to move the materials between the magazines 22-23 and the storage railcars; the portal conveyor being movable on auxiliary tracks rigidly associated with the frame 11.
The frame 12 is constituted by strong side members 30 bearing a conveyor 31 for the removal of old sleepers linked to the conveyor 21, a conveyor 32 for new sleepers linked to the conveyor 24, an operating cabin 33, the operating system 40-50-60-70 according to the present invention and a supporting tracked shoe 34, raisable and lowerable by means of a hydraulic jack 35 to support the frame in the place of an axle 36 serving only for transfering the operating unit.
The operating system according to the invention comprises first grip means 41 for gripping the old sleepers T v , for removing them from their original seat and depositing them on the removal conveyor 31, a rotating operating element 51 for prearranging each original seat S 1 stripped of its related old sleeper; at least one strike element 61 for compacting the new laying plane in each prearranged seat S 2 and forming new seats S 3 , second grip means 71 for gripping and laying the new sleepers T n in the new seats S 3 .
More particularly, said first grip means comprise two identical paired grip elements arranged on the two outer sides of the side members 30 and adapted to act separately at the opposite ends of each sleeper. Each grip element is formed by a wedge 42, slideable on a corresponding column 43 connected at the articulation 144 to the frame 12.
As is clearly shown in the figure, each wedge 42 is intended to be sunk into the ballast on the rear side of each sleeper to be removed and for this purpose it is controlled by a vertical movement jack 44. It should be observed that the wedges 42 just partially engage the rear surface of the sleepers, without affecting the old laying plane thereof; the sinking being adjusted so that the end of the wedge is always above the lower resting face of said sleeper. A grip jaw 45 cooperates with each wedge 42 and is articulated to the wedge and controlled by an actuator jack 46. A third jack 47 is arranged to produce the controlled oscillation of the column 43. The operating cycle of said first grip means is as follows: when, upon advancement of the railcar, the axis of the columns 43 is aligned with the rear face of the sleeper to be removed, the jacks 44 are actuated and cause the sinking of the wedges 42 in the manner described above. Once the sinking has occurred, the jacks 46 are activated to close the grip jaws 45 on the sleepers.
During these operative steps the advancement of the railcar is compensated by the free or controlled oscillation of the columns 43 about their own articulations 144 (anticlockwise with reference to the drawing). Once a preset oscillation angle has been reached, the jacks 44 are activated in the opposite direction and cause the lifting of the wedges 42 and of the sleeper which is thus removed from its own original seat S 1 and lifted to be arranged on the conveyor 31 by virtue of the activation of the jack 47, which causes the opposite (clockwise) oscillation of the columns 43, and by virtue of the opening of the grip jaws 45.
The rotating element 51 is arranged immediately downstream the grip means 41 with reference to the advancement motion of the railcar, and comprises a milling roller 52 arranged with its own axis transversely to the direction of advancement of the railcar and supported by a supporting plate 53 bearing a motor 54 for the actuation of the roller 52 by means of a transmission 55. The plate 53 is supported, with the possibility of vertical movements, on a pair of guiding and retention columns 56 connected at the articulation 57 to the frame 12. A jack 58 is provided to produce controlled vertical movements of the plate 53 and therefore of the milling roller 52 and jacks 59 are provided to produce the oscillation of the columns 56 about their own articulations 57.
Preferably, with the rotating element 51 there is associated a means for sorting rubble lifted out of the seat S 1 to be prepared and for depositing said rubble at the sides of the ballast.
As shown in FIG. 3, the sorting means comprises two conveyor belts 590-591 extending, transversely to the direction of advancement of the railcar, respectively between a corresponding drive wheel 592-593 and a return wheel 594-595. The conveyors 590-591 may be actuated in opposite directions to deposit the rubble lifted by the roller 52 on the two sides of the ballast or in the same direction to deposit said rubble on one side or on the other.
The operation of the rotating element 51 is as follows: the columns 56 being inclined in the direction of advancement of the railcar, when the milling roller 52 is aligned with the seat S 1 to be prepared, it is lowered into said seat by means of the jack 58, the motor 54 having been activated. The roller prepares the seat by removing the excess rubble for a preset depth and by imparting to the prepared seat S 2 a channel-like profile; the removed rubble being accumulated partially to the sides of the ballast and partially on the rear and/or front side of each seat. Also in this case the continuous advancement of the railcar is compensated by the free or controlled oscillation of the columns 56 about their own articulations 57. Once a preset oscillation amplitude (corresponding to a preset work time of the roller 52) has been reached, the jacks 58 and 59 are activated in sequence and respectively cause the lifting of the roller out of the prepared seat S 2 and the reverse oscillation of the columns 56, which return to their initial position to start a new working cycle in the oncoming seat to be prepared.
The strike element 61, arranged immediately downstream the rotating element 51, is constituted by a vibrating mass 62 supported by a frame 64 by means of a counterframe 63. The vibrating mass 62 is capable of executing longitudinal horizontal movements (parallel to the direction of motion of the railcar) with respect to the frame 64 by means of retention and sliding guides (not illustrated) interposed between said counterframe and said frame. In turn the frame 64 is supported and guided by vertical uprights 65 with respect whereto it can perform vertical lifting and lowering movements. A jack 66 controls the horizontal movements of the counterframe 63 and a jack 67 controls the vertical movements of the frame 64, furthermore applying to the vibrating mass 62 the required vertical work load.
As is clearly shown in the figure, the vibrating mass 62 has a trapezoidal shape to impart to the new seat S 3 a caisson-like shape defined by a laying plane P p and by front shoulders S p . A control means 68, for example constituted by a wire-wound potentiometer, is provided to check the sinking of the mass 62 and accordingly the preset level of the laying plane P p .
The operation of the strike element is the following: the counterframe 63 being at the end stop position of work start, with respect to the frame 64 (to the left with reference to FIG. 2), and the frame 64 being raised, the mass 62 is aligned with an approached prepared seat S 2 , due to the motion of the railcar, the jack 67 is activated and causes the lowering of the frame 64 and the working engagement of the vibrating mass in the seat S 2 . The mass 62 is activated and shapes the seat, compacting and setting the laying plane P p to the preset level. During this operation the translatory motion of the railcar is compensated by the free or controlled horizontal motion of the counterframe 63 with respect to the frame 64, the excursion whereof is set with reference to the preset maximum work time for the mass 62. The mass 62 is stopped by the control means 68 when the level of the plane P p reaches the preset position. Once the mass 62 has stopped, the jack 67 and the jack 68 are activated in reverse to respectively lift the frame 64 and to return the counterframe 63 and the vibrating mass 62 to their initial position.
To reduce the work times in the described step of shaping of the new seat S 3 and of formation of the new laying plane P p , the machine may be fitted with two strike elements 61 arranged one after the other with reference to the motion of the railcar and operating in series each for a time equal to half the overall required time.
The second means 71 for gripping and laying the new sleepers T n in the new seats S 3 are arranged downstream the strike element or elements 61 and are constituted by a pair of identical grip shoes 72 supported freely slideable on corresponding uprights 73 oscillably pivoted at 74 to the outer sides of the side members 30. Each shoe 72 is controlled by a corresponding vertical movement jack 75 and each upright 73 is subject to a jack 76 adapted to cause the oscillation of said upright to move it from a position of removal of the new sleepers T n from the conveyor 32 (drawn in broken lines in FIG. 2) to a position of laying of said sleepers in the new seats S 3 and vice versa.
Each shoe is provided with elements for gripping the sleepers constituted by a grip jaw 172 actuated by a jack 173. To allow the operation of the grip means 71 with an oscillating cycle, the end of the conveyor 32 is provided with a fold-down flap 77, actuated by a jack 78, on which there stops the first sleeper T n1 of the series of sleepers fed by the conveyor 32.
The operation of the means 71 described above is as follows:
the uprights 73 being inclined as indicated in broken lines in FIG. 2, the jacks 75 are actuated to move the grip shoes 72 to engage the sleeper T n arranged on the flap 77. Subsequently the jacks 173 are activated to grip the sleepers, the jack 78 is activated to fold down the flap 77 and the jacks 76 are activated to cause the oscillation of the uprights 73, which arrange themselves vertically as illustrated in solid lines in FIG. 2. When, by virture of the advancement motion of the railcar, the new seat S 3 appears below the new sleeper suspended from the shoes 72, the jacks 75 are actuated and the shoes 72 are lowered to move the sleeper into said seat. The opening of the jaws 172, the separation of the sleeper from the shoes and its laying on the plane P p of the seat S 3 occur however only after the combined positive check of a pair of control means adapted to ensure the regular spacing of the successive sleepers. A first control means is constituted by a wheel 80, rigidly coupled to the frame 11 and rolling on the tracks 15. The wheel 80 is connected to a rotating potentiometer or to a pulse generator adapted to supply a control signal for laying the new sleeper when the railcar has travelled for a distance equal to the spacing pitch between one sleeper and the next. A second control means is constituted by a rod 81 rigidly coupled to the frame 12 and supporting a pair of sensors 82-83 (for example microswitches) separated by a distance equal to said spacing pitch and adapted to check said pitch by detection on a pair of previously existing sleepers or of previously laid new sleepers.
When the new sleeper is controllably laid as described above, the jaws 172 are opened, the shoes 72 are raised and the uprights 73 are moved angularly to the initial position for the extraction of a new sleeper.
Once the laying has been performed, the new sleepers T n are secured in their respective caisson-like seats S 3 by means of the packing of rubble in the interspaces 90-91 indicated in FIG. 4. The packing rubble is at least partially constituted by new (or regenerated) material and at least partially constituted by the rubble extracted during the step of preparation of the original seats and accumulated behind and laterally to each prepared seat. This packing rubble is subject to compaction by a pair of vibrating masses 93 supported, with possibility of controlled longitudinal motions, by corresponding frames 94 arranged to the sides of the track-mounted supporting shoe 34.
The arrangement of the vibrating masses at the shoe 34 is particularly advantageous since the latter rests on the sleepers, preventing any unwanted movement thereof which may occur during compaction.
As described for the strike element 61, the frames 94 are also subject to jacks 95,96 respectively, for longitudinal movement and for vertical movement.
From the preceding description it is apparent that the railcar according to the present invention, in accordance with the stated aim and objects, allows the partial regeneration of railways, since the operating system 40-50-60-70 may be activated exclusively at the selected old sleepers to be replaced. Furthermore the actions of the rotating element 51 and of the strike element 61 may be adjusted so as to prepare a new laying plane P p at such a level as to allow the laying of new sleepers having a greater height than the old ones without varying the laying plane of the tracks, while the shoulders of old rubble which are left between two consecutive new seats ensure an effective retention of the new sleepers against the longitudinal movements of the track, allowing thereby a correct adjustment of the inner tensions on the tracks.
In the variated aspect of FIG. 5, the first means for gripping and removing the old sleepers T v are composed of a pair of operating elements acting separately and in succession. A first operating element is constituted by two paired oscillable arms 402 pivoted at pivot 403 on the sides of the frame of the operating unit. Each arm is controlled by a jack 404 and is provided with an end hook 405 capable of engaging with the track bolting plate 406, carried by the old sleepers T v , when the jack 404 is actuated to lower the arm as indicated in broken lines in the figure. The engagement of the hooks 405 with the plates 406 and the advancement of the railcar cause the overturning of the old sleepers which are extracted from their original seat S 1 and left on the bank, in the inclined position illustrated in the figure, by virtue of the upward rotation of the arms 402 caused by the jacks 404 and the consequent disengagement of the hooks 405 from the plates 406.
In operative sequence with respect to the arms 402 there acts a second operating element for the grip and removal of the old sleepers T v , also constituted by a pair of oscillable arms 409 pivoted at pivot 408 to the sides of corresponding wings 410 rigidly associated with a slider 411. The slider 411 is movable along longitudinal guides carried by an inclined plate 412 rigidly associated with the frame 30 of the unit and controlled by a double-action jack 413 adapted to move the slider with respect to the plate and therefore to the frame. A jack 414 is provided to produce the oscillation of each arm with respect to the wings 410 of the slider. The end of each arm is provided with a grip wedge 415 with which there cooperates a grip jaw 416 controlled by a jack 417.
The operation of this second operative element is as follows: the arms 409 being lowered as indicated in the figure, by virtue of the extension of the jacks 414, the wedges 415 meet and engage--as an effect of the advancement motion of the railcar--with the overturned sleepers abandoned by the hooks 405 of the first operating element 402. Then the jacks 414,417 are actuated in succession. The jacks 417 are adapted to close the grip jaws 416; the jacks 414 are adapted to raise the arms 409 moving them to the position illustrated in broken lines in the figure, in which said arms are parallel to the plate 412 in turn inclined so as to be parallel to the removal conveyor 31. At this point the jack 413 is energized and moves the slider 411 in the direction indicated by the arrow F in the figure, moving the wedge-like ends 415 of the arms 409 above the conveyor 31, and when the translatory motion is complete the jaws 415 are released to deposit said sleepers on said conveyor. The slider 411 is then moved in the reverse direction and the arms 409 are lowered to start a new grip cycle.
In the variated aspect of FIGS. 6 and 7, the rotating operating element 520 is constituted by a track 521 provided with profiled scarifying blades 522 and extending transversely with respect to the direction of advancement of the railcar between two pinions 523 keyed on corresponding shafts 525-526 one whereof is a driving shaft (of the two pinions, only pinion 523 is shown in FIG. 6, the top plan view of FIG. 7 showing the two respective shafts 526 and 525). The track and the related motor and transmission pinions are supported by a movable frame 530 provided with horizontal sleeves 531 fitted, freely slideable, on corresponding cylindrical supports 532 with horizontal axis. The supports 532 are in turn rigidly associated with a frame 533 provided with vertical sleeves 534 fitted, freely slideable, on guiding and retention columns 535 rigidly associated with the frame 12 of the railcar. A double-action jack 536 controls the horizontal movements of the frame 530 with reference to the supports 532 and a jack 537 controls the movements of the frame 533 with reference to the columns 535. According to this variated aspect, the translatory motion of the railcar is thus compensated--so as to allow the track 521 to prepare the seat S 1 --by the horizontal free or controlled motion of the frame 530 and this allows to also associate with the frame 530 the strike element 61 to form a single operating unit. For this purpose the frame 530 is provided with strong ledges 540 for the support of a first vibrating mass 62 and possibly of a second vibrating mass acting in series to the first as previously mentioned; the second mass, if provided, being connected to the ledges 540 by means of articulating connecting rods 541.
The advantages of the arrangement described above with reference to FIG. 6 reside, as well as in the fact that the rotating element and the strike element are combined into a single operating unit, in the fact that one may impart to the scarifying blades 522 of the track 521 any profile and in particular the trapezoidal caisson-like profile of the seats S 3 similar to that of the vibrating masses 62.
In the variated aspect of FIG. 8, adapted to an operating unit provided with two strike elements 61 paired in series, an advantageous embodiment of the second grip means 71 is illustrated. According to this variated aspect, each upright 730 is provided with two shoes 721-722 paired longitudinally and rigidly spaced by a distance equal to the spacing pitch between two consecutive sleepers. The shoes 721-722--provided with respective grip jaws 1721-1722--act simultaneously for gripping and laying pairs of sleepers T n1 -T n2 which are positioned beforehand on a loader 725 provided at the end of the conveyor 32. The loader 725 is provided with elastically yielding stop pawls 730-731 adapted to space by one pitch unit the sleepers T n1 -T n2 of each pair and is slideable on a supporting frame to pass from a position of reception of the sleepers, drawn in solid lines in the figure, to one of distribution, drawn in broken lines, wherein each pair of sleepers is aligned with the respective grip shoes 721-722. A jack 735 controls the movements of the loader from the first to the second position and vice versa.
The railcar thus conceived is susceptible to numerous modifications and variations, all within the scope of the inventive concept; furthermore all the details may be replaced with technical equivalent elements.
In practice the materials employed, as well as the dimensions, may be any according to the requirements and the state of the art.
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The railcar includes: an operating unit provided with equipment for removing the old tracks and with supporting elements for advancing on the old sleepers stripped of their tracks, and, in sequence: first elements for gripping the old sleepers, capable of executing controlled cyclic oscillatory and vertical movements to grip the old sleepers, for removing them from their original seat and depositing them on a removal conveyor; a rotary operating element, capable of executing controlled cyclic oscillatory and vertical movements for the prearrangement of each seat stripped of its related old sleeper; at least one strike element, susceptible to longitudinal motion with respect to the frame of the operating unit and subject to fluid actuated control elements for the compaction of the new laying plane in each prepared seat; second grip elements, capable of executing controlled cyclic oscillatory and vertical movements for controllably resting them on the laying plane of each regenerated and compacted seat; and strike elements also capable of executing controlled longitudinal and vertical movements, for the packing of rubble for filling and final securing, fed into the spaces comprised between the walls of the regenerated seat and the new laid sleeper.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 286,374 entitled "Offshore Platform Location" filed Sept. 5, 1972 by Arthur L. Guy et al and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to offshore structures which are fabricated at a point remote from the point where they are ultimately located. More particularly, the invention is concerned with a method and apparatus for unitizing an offshore jacket of extensive length for an offshore platform and locating same at a selected location. In its more specific aspects, the invention is directed to method and apparatus for use in extremely deep waters where an offshore platform is supported for various purposes such as, but not limited to, well drilling, production of oil and gas, storage of oil and the like, and supporting navigational aids and the like.
2. Description of the Prior Art
It has been known for many years that structures may be located in deep waters by making the structures buoyant and floating them to a selected location in a body of water either in an assembled or non-assembled condition. To accomplish this, however, where heavy seas may be encountered and long tows may be necessary, excess buoyancy, as much as 35 percent or more, must be built into the structure, which for a platform jacket or support in waters of 500, 750, 1000 feet or more may require flotation members each of which may be as large as a submarine.
It has also been known that flotation tanks may be added to sections of an offshore structure and the sections gradually added one on top of each other until the completed structure is above water level. Another possible method is to build an offshore structure close to land in shallow water or on land and add buoyant sections to it as the structure of increasing height is skidded or towed farther and farther to sea into deeper water until the desired location is reached.
It has been disclosed in the prior art that supporting members for offshore structures may be sealed by frangible or flexible (rupturable) diaphragms to maintain columns free of debris and to confer buoyancy thereto.
The art has also described the floating of an offshore structure to an offshore location on a barge and then launching it and sinking it at a selected point. This, too, is attendant with difficulties because the usual barge is only about 300 to 400 feet in length, and while larger barges may be built, the greater the length the greater are the problems therewith.
The art has, in addition, described fabricating an offshore structure at one location in sections, floating the sections on one or more vessels or barges, launching the sections into water at or near another location for positioning the offshore platform, aligning and connecting the sections together and then sinking the connected sections to form a support for a platform.
SUMMARY OF THE INVENTION
The present invention may be briefly described and summarized as involving a method for utilizing a sectional offshore jacket to support an offshore platform deck and locating the unitized jacket at a selected location. In the present invention, the jacket (or deck support) to be located in deep water is fabricated on shore or at a location remote from its ultimate position. Due to its extensive length which may range from 500 to 1500 or even more feet, the jacket is fabricated in a plurality of sections designed to interconnect with each other at sea and form a unitary structure. Each section of the jacket is provided with sufficient buoyance to float but insufficient buoyance to be practical for a long tow (say one of more than 100 miles) or one in rough seas. On launching a section it should be floating so that it is just awash but still may support workmen to install equipment for moving or pulling the sections together and to perform other tasks which may be necessary. A part of this pulling equipment may be preinstalled, but it may be removable after it has performed its designed service.
After the sections have been aligned and then moved or pulled together, the sections are fixedly connected together first by bolting and then by welding. Guide means ensure proper alignment of the legs of the sections prior to fastening such legs together. The legs of the sections are connectable together at both the water's surface and fully submerged. After the bolting of flanges the geometry of the sections form an internal habitat for welding the legs of the sections together. No outside cofferdam is needed at the water's surface or fully submerged to permit welding of the legs together. Conventional welding is conducted internally within the legs of the sections. Man-sized access tubes extend from above the surface of the water to each leg (at the water's surface and fully submerged) of either section adjacent the connection of the common leg of the sections to permit a welder(s) to enter each leg and weld the sections of each leg together from the interior of the joint thus connecting the sections together structurally at atmospheric pressure. Such a weld develops the full strength of the adjacent pipe sections. Then with the unitized jacket, without deck, floating horizontally, the pulling equipment may be removed and motor driven sea cocks connected to power means. The power means may be located on the jacket section or on a separate vessel as may be desired.
The sea cocks are opened and the unitized jacket rotates from horizontal to vertical as it sinks, the upper end being supported or lifted as flooding takes place by a crane on a barge or other vessel to ensure proper location. Thereafter pilings are driven through the hollow legs into water bottom and the unitized jacket is anchored. The crane then lifts and lowers or stabs a prefabricated deck having depending means into the open legs of the unitized jacket or other means provided to receive the supporting depending means from the platform. Thereafter, the deck may be used as desired for oil and/or gas production, storage, navigational aids, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further described by reference to the drawings in which:
FIG. 1 is a side elevational view of a jacket in two sections in the course of launching;
FIG. 1A is a cross-sectional view of the upper section taken on line 1A--1A.
FIG. 2 illustrates the alignment of thw two sections preparatory to connection or unitization;
FIG. 3 shows the connected unitized sections being rotated and sunk;
FIG. 4 illustrates the placement of a deck on the unitized structure after anchoring by driving piling through the legs into water bottom;
FIG. 5 is a detail of a quick connection means on each of the legs of the sections of the jacket shown on a surface leg;
FIG. 5A shows an access tube connection into a submerged leg;
FIG. 6 is a detail of fixed connection means and sealing means in each leg of each jacket section for providing buoyancy;
FIG. 7 is a detail of sea cocks for providing a flooding means;
FIG. 8 is a detail of an upper end of one leg of a jacket section and a showing of a junction box for control of sea cocks;
FIG. 9 shows a portion of the upper and lower sections connected together and means for connecting the control lines to the sea cocks; and
FIGS. 10 to 15 show the steps of connecting the jacket sections together using modified quick connection guide means and illustrating the manner in which the legs of the sections may be welded together.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing and particularly to FIG. 1, numeral 11 designates an upper jacket section for an offshore structure which has been launched from a barge or vessel such as 12 into a body of water 13 which may be, for example, 1,000 feet in depth but which may be from about 500 to about 1,500 feet or more deep. Numeral 14 designates a second jacket section (hereinafter referred to as the lower jacket section) which is designed to matingly engage with upper jacket section 11 and form a unitized jacket structure as will be described. The sections 11 and 14 are fabricated on shore or at a point remote from which they are launched to be connected together and have only sufficient buoyancy to float substantially awash, such that little excess buoyancy is provided. Therefore, due to the length of the jacket sections 11 and 14 they are transported on barge 12 to the place of launching and location; otherwise if they were fabricated in one piece for towing or in sections for towing, excess buoyancy in the range from about 30 percent to about 40 percent would have to be provided to ensure stability and integrity of the structure.
The jacket sections 11 and 14 may have any desired number of legs, as for example, three legs, four legs (as illustrated herein) or eight legs and are provided with transverse and cross struts 15 and 16 and other bracing as necessary to provide rigidiy to the structure. The legs 20A (surface legs) and 20B (submerged legs) of both jacket sections 11 and 14 are at least in part hollow to provide buoyancy and a passageway for the piling used to anchor the unitized jacket to the ocean floor and for permitting man's access for purposes of welding the joint connecting the legs of the sections. The mating ends of the legs 20A and 20B at each section 11 and 14 are provided with connector flanges 22 which are to be bolted or otherwise connected together when the two sections are brought together.
Referring now to FIG. 2, a work barge 23 provided with a crane means 24 and an auxiliary power supply means 25 is moved on location and is operably connected to the lower section 14 by lift lines 26 for maneuvering the sections together. At this time a removable power winch means 27 is attached to the upper side structure of section 11 and by means of a cable 28 passing over a sheave or pulley 29 and attached to the lower section 14 as shown provides means for pulling the two sections together. A flexible power supply conduit (not shown) is then connected between the winch 27 and the power supply means 25 on barge 23.
A pre-alignment and latching means generally designated as 30 (see FIG. 5) is provided to align and latch the two sections together just prior to the mating engagement of the flange 22. Means 30 consists of a latch prong 31 attached to the structure of section 11 and a latching sleeve 32 (provided with a flared bell shaped opening 33) which is attached to the structure of section 14. As the two sections are brought together the prong 31 enters the sleeve 32 and correctly aligns the flanges 22. The prong is latched in the sleeve by a spring biased latch in housing 34. A means 30 may be positioned adjacent each of the legs 20A and 20B of the two sections; however, only two means 30 may be used if they are positioned on legs diagonally spaced apart.
The flanges 22 of upper section 11 are provided on their connecting surfaces with hard rubber gaskets 35 to protect the surface of the flange during engagement operations. Such gaskets may also be provided on the flanges of section 14 is desired and, apart from protection, also compensate for any slight misalignment. The flanges 22 are then bolted and welded together at each leg 20A and 20B to unitize the two sections 11 and 14 and provide a single jacket generally designated by the numeral 60. The power winch 27 maintains tension on cable 28 until all of the flanges 22 have been bolted and welded together.
The surface leg 20A, as illustrated in FIG. 5, contains an access tube 70 connected into the upper section 11 to permit a welder access to the joint connecting the upper and lower sections to weld flanges 22 of those sections together. The access tube 70 is also shown in FIG. 6. A cap 71 for access tube 70 may be provided to prevent water or other matter from entering the legs through the access tube when no welding operations are being conducted. FIG. 5A shows a similar access tube 72 connected into submerged leg 20B adjacent flange 22 of lower section 14. Either access tubes 70 or 72 may be connected into the legs of either of the sections 11 or 14.
Referring now to FIGS. 6, 7 and 8, it will be seen that the legs 20A and 20B of each of the sections 11 and 14 are each provided with two sets of diaphragms 40 and 41 adjacent both ends thereof. Diaphragm 40 may be constructed of plastic or other flexible material and is provided to afford buoyancy to the legs while diaphragm 41 may be constructed of any of a number of common construction materials and acts as a safety backup for diaphragm 40. Both diaphragms are flexible to some extent and are frangible or rupturable for purposes described hereinafter. The sets of diaphragms form a watertight compartment 42 in each of the legs of each of the sections. Connected to each end of the legs 20A and 20B and fluidly communicating with the chambers 42 are sea cocks 43 for admitting sea water into the compartments when desired. The sea cocks 43 are operated by motor means 44 which by fluid power lines 45 are each connected to a common junction box or manifold 46 which is attached to the upper end of one of the legs 20A of the upper section 11 as shown in FIG. 8. The lines 45 of the upper section 11 and those of the lower section are joined together by connector means 48, as shown in FIG. 9, after the two sections have been unitized. The sea cock at one end of compartment 42 acts as a flooding valve and the one at the other end as an air escape means. The legs may be divided into several compartments if desired with each provided with two sea cocks such as 43. The legs 20A and 20B of each section are provided with spaced apart centralizers means such as pile guides 50. Each section may have a door or doors (not shown) in each leg adjacent the flanges 22 through which a welder may enter to weld the flanges together from the interior of the legs 20A and 20B as will be explained in more detail with respect to FIGS. 10-15. The door may be previously formed or may be cut into legs 20A and 20B and then when welding is completed welded shut to close such entrances to legs 20A and 20B. Of course, water must be removed after the door is opened and the legs 20A and 20B kept free of water until deliberately flooded.
The power winch 27 is now removed from the structure and a power conduit line 45' as shown in FIG. 3 is connected between the power source means 25 on barge 23 and the junction box or manifold means 46 on the upper end of structure 60.
The crane lines 26 are then connected to the upper end of the structure 60 and the assembly is now in position to begin flooding of the legs 20A and 20B.
As the sea cocks are opened remotely from the barge 23 sea water enters the compartment 42 of legs 20A and 20B the jacket 60 rotates to the position shown in FIG. 3 with the upper end thereof controlled by the crane 24 so that it sinks gently to the ocean floor with the upper end of the structure extending above water as shown in FIG. 4. The extension distance above the water surface may be anywhere from about 10 to 100 feet as may be desired.
Piling 61 is then run in through each of the legs 20A and 20B of the structure and by means not shown is driven into the ocean floor a substantial depth to anchor the structure. As the piling is run through the legs, it ruptures and passes through the diaphragms 40 and 41. After the structure 60 has been anchored, a deck section 70 positioned by the crane 24 is connected to the upper end of the structure.
Referring to FIGS. 10 to 15, the two sections, 11 and 14, are launched and moved or pulled together as described with respect to FIGS. 1 and 2 (please note that the upper and lower sections shown in FIGS. 10 and 11 are reversed from the showings in FIGS. 1 and 2 and 5 to 9). Access tubes 70', each provided with a cap 71', are connected to surface legs 20A of lower section 14 and access tubes 72', each provided with a suitable cap 73', are connected into each of the submerged legs 20B of upper section 11. These tubes are connected into legs 20A and 20B near flanges 22 of those legs. Whether these tubes are located on the upper or lower sections is a matter of choice.
An alignment and latching, mating guide means generally designated 74 are mounted on each of the legs to be connected together in making up the sections. A guide member prong 75, shown connected by suitable support brackets 76 to surface leg 20A of lower section 14 is conically shaped and provided with latches 77. A guide member sleeve 80 shown connected by suitable support brackets 81 to surface leg 20A of upper section 11, is also formed of a conical shape for receiving guide prong 75 and is provided with latch openings 82 for engagement with latches 77. Similarly, a conically shaped guide member prong 85 provided with latches 87 is connected to each of the submerged legs 20B of section 14 by bracket 86 and a conically shaped guide sleeve 90 provided with suitable latch slots (not shown) is connected to each submerged leg 20B of upper section 11 by brackets 91. Guide prong 75 and guide sleeve 80 are longer than guide prongs 85 and guide sleeve 90. The differences in the sizes of the guide prongs on the surface legs and guide prongs on the submerged legs are to ensure that the submerged legs are properly aligned before engagement of guide prongs 85 in guide sleeves 90. Once guide prongs 75 are engaged in guide sleeves 80, the surface legs are properly aligned and the lower submerged legs are also generally aligned properly and final, precise alignment is achieved by the guide prongs 85 and guide sleeves 90.
FIG. 10 illustrates the upper and lower sections being brought together. FIG. 11 shows upper and lower sections engaged and fully made up. FIG. 12 shows the guide prongs and guide sleeves in more detail. The flanges 22 are the same as those previously described with respect to FIG. 5.
To facilitate connection of access tube 72' into legs 20B guides 95 are connected to cross struts 16 and to upper or surface legs 20A. Seating tubes 96 shown more clearly in FIG. 13 make a sealing connection at 97 with the lower end of access tubes 72' after they have been run in through guides 95. Seating tubes 96, as shown in FIGS. 14 and 15, are welded to the sumberged legs 20B. At the connection of tubes 96 and tubes 20B, manhole openings 98 are formed in tubes 20B.
In operation, after sections 11 and 14 are connected together and bolted to each other and properly sealed as described herein, water is pumped out of legs 20B. Then a welder, as illustrated in FIG. 13, is lowered through access tube 72' into leg 20B adjacent flanges 22 which are shown have been sealed and bolted together. The welder then welds the two sections of leg 20B together from the interior of the legs. All of the legs 20B are welded in that manner. As illustrated in FIG. 15, after the welding of the legs has been completed, the welder may then cover opening 98 with a plate 99 and weld the plate to sealingly close opening 88. If desired, access tube 72' may then be removed. Legs 20A are welded together in a similar manner. The welder is lowered into a leg 20A through access tube 70' and welds the two sections of leg 20A togehter from the interior of the legs. All of the legs 20B are welded in that manner.
Commercially available means other than bolts may be employed to secure the sections together in order to effect proper sealing of the sections prior to pumping out the water. Under some circumstances the guide prongs and guide sleeves alone, without bolts or other type connecting means, could achieve sufficient sealing of the sections to permit pumping out of water and welding.
Other changes and modifications may be made in the illustrative embodiments of the invention shown and/or described herein without departing from the scope of the invention as defined in the appended claims.
It will be clear from the foregoing description taken with the drawing that a new, useful, unobvious and therefore patentable result is obtained in unitizing and installing jackets to support offshore structures in waters of great depths.
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A method for joining two or more jacket or substructure components of an offshore platform in the water to form a single jacket unit. An offshore platform is located in deep water by dividing a jacket or support of extensive length therefor into at least two sections which have only sufficient buoyancy to float at water surface when the sections are launched from at least a vessel at a selected location. The sections are aligned and connected together. Guide means ensure proper alignment of the legs of the sections. Access tubes from the surface of the water to the hollow legs permit direct internal welding in securing the legs of the sections together. The sections are then sunk at the selected location until the jacket is in an upright position at which point it is anchored by driving piling through the jacket's hollow legs into the sea floor, following which the deck of the platform is placed or stabbed on the anchored jacket.
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BACKGROUND OF THE INVENTION
Escherichia coli is a very widespread, often pathogenic, organism which is found in the human as well as domestic animals. The organisms vary in their virulence. While the E. coli infection is a widespread problem, it is especially serious in the raising of pigs. It is known that newborn piglets have very low levels of immunity against infection. This level of immunity is extremely low with respect to enterotoxogenic E. coli. Under practical pig raising conditions, a substantial number of newborn piglets are infected with enteric colibacillosis which gives rise to acute diarrhea. The effects of this diarrhea, especially the dehydration accompanying it, are of such a level of acuteness that a substantial fraction of the piglets thus infected die during the first six days of life.
Attempts have been made heretofore to isolate immunizing factors and administer same to the piglets. One such approach was taken by Rutter et al (Infection and Immunity 13, 667/676 (1976)) wherein an exocellular factor designated K88 was administered to pre-partum sows whose colostrum was then fed to newborn piglets exposed to virulent E. coli infection. In tests carried out on four vaccinated and four unvaccinated litters of between five and eight piglets per litter, the mortality rate of piglets nurtured by vaccinated dams was 12% while that of piglets nurtured by non-vaccinated dams was 68%.
It should be noted that previous studies directed to the nature of the K88 antigens clearly establish that the K88 antigen is not a pilic antigen. Stirm et al (Journal of Bacteriology, 93 740 (1967)).
While these results indicate an improvement over no protection at all, a more effective vaccination procedure and substrate was sought.
SUMMARY OF THE INVENTION
There is provided a vaccine composition capable of raising the antibody level of a vertebrate subject to a level sufficient to provide protection against infection caused by organisms of a first group of strains of piliated E. coli comprising:
(a) Pili derived from a second group of strains of piliated E. coli organisms wherein cells of organisms of said first group are agglutinable by serum containing antibodies against pili from said second group, said first group consisting of strains which may be the same or different from the strains of said second group; and,
(b) a pharmaceutically acceptable carrier.
While there is exemplified in this application a vaccine containing pili from a single pre-determined strain which is effective against infection caused by organisms of the same strain, as well as organisms of a different strain, but same pilic serotype, vaccines which contain pili from several different strains are included within the scope of the present invention provided, of course, that each of said pili will cross-react immunologically with at least one of the infecting organisms.
An important enterotoxogenic strain of E. coli was isolated from piglets with diarrhea and shown to be virulent and causative of the natural disease when inoculated into immune-colostrum deprived piglets. This virulent strain, though sparsely piliated, was grown and selected for well-piliated clones. These clones were grown and maintained on blood base agar medium and the pili therefrom separated from the cells and subjected to several cycles of crystallization in aqueous magnesium chloride followed by resolubilization in low ionic strength neutral buffer.
Pregnant dams were injected, pre-partum, with pili. After parturition, piglets were allowed to suckle the immunized dams. Thereafter, the piglets were challenged intragastrically with an amount of E. coli previously found to represent one LD 50 dosage.
No deaths occurred in the immunized group. Although incidence of diarrhea was noted in the immunized group, members of this group recovered rapidly and showed substantial weight/gains over the non-immunized group.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The vaccine compositions of the present invention comprise pili of a pre-determined strain which pili meet certain criteria.
It is known that E. coli organisms carry a number of antigenic factors known as "O" antigens (outer membrane) "K" (capsule) and the like, as well as, for certain strains, pili. The criterion of the strain of organisms selected shall be that the strain to be protected against shall be piliated, that the protecting strain shall be piliated, and that the pili of one strain shall give rise to antibodies which cause cells of the other strain to agglutinate in their presence. This simple criterion means that the protecting strains may be homologous or heterologous with respect to the infecting strain as long as the pili of each are immunologically similar. This similarity may, as above, be readily determined by one skilled in the art without undue experimentation.
The pili are selected and obtained by methods well known in the art. One important disease preventable by the methods of the present invention is neonatal porcine colibacillosis. This disease is caused by a gastrointestinal infection of newborn piglets by E. coli infection. One infecting strain has been found to be E. coli 987.
Culture of E. coli 987
Samples of a parental strain E. coli 987 (09:K 103:NM) were isolated from piglets suffering from enterotoxogenic E. coli infection passed through still broth, and colonial forms selected therefrom, to provide a well pilated clone designated E. coli 987-5 (ATCC 31346). The clone is then grown on blood base agar medium. The pili were separated from the cells by blending and centrifugation in a low ionic strength neutral buffer such as 0.01 M MOPS buffer pH 7.5. The pili are crystallized from the buffer by addition thereto of concentrated magnesium chloride (aq) to bring the strength of the buffer up to the 0.10 M whereupon the pili crystallize. The crystalline pili are taken up in a low ionic strength neutral buffer such as 0.01 M MOPS buffer pH 7.5 and reprecipitated with magnesium chloride in a similar manner. It is preferred to subject the pili to from one to five cycles of recrystallization. The procedure used is that substantially set forth in Brinton, Trans. N. Y. Acad. Sci 27, 1003 (1965).
The final preparation of the pilus vaccine consists of dialyzing the recrystallized pili against saline, suitably saline containing formaldehyde, most suitably containing between 0.1 and 0.7 M formaldehyde. The pili thus prepared are of a quality sufficient to pass the standards of the Bureau of Biologics, Food and Drug Administration, for general safety, sterility, and pyrogenicity.
The pili may be administered orally--say, in capsule form--or by injection--that is to say, subcutaneous, intradermal, or intramuscular injections. Where the mode of administration is by injection, since the pili are solid, any pharmaceutically acceptable suspending medium may be employed. It has been found especially useful to employ saline, suitably containing formaldehyde, as the vehicle or suspending medium. It is preferred to use 0.7-0.9, most suitably 0.85%, saline containing 0.01 to 0.1, most suitably 0.05%, formaldehyde. The concentration of pili in the vehicle is not critical. The sole criterion of desirability being that the pili shall be sufficiently finely divided to provide a suspension which meets generally accepted standards of syringeability. A concentration of 0.1-1, preferably about 0.5 mg of pilus protein per ml of suspending medium is especially suitable.
It is generally preferred to administer the vaccine composition in more than one dose separated by a pre-determined time factor. This time factor is selected to permit the formation of an adequate titer of antibodies to the pili in the injected subject. In the case of pregnant sows, it has been found suitable to administer the vaccine composition at least once between 5 and 30 days pre-partum (farrowing). It has been found most suitable to inject the sow subcutaneously with a first injection 27 to 21 days before farrowing and a second injection 13 to 7 days before farrowing.
Since there are no local or systemic toxic effects engendered by the injection of vaccine, there appear to be no upper limits to the dosage administered. It has been found suitable, however, to administer between 1 and 100 micrograms of pili per kilogram of body weight, most suitably about 60 micrograms per kilogram of body weight in each injection.
After farrowing, the piglets are set to suckle an immunized dam. While, in the normal course of events, it would be expected that a newborn piglet would be suckled by its own dam and thereby ingesting colostrum or milk containing the pre-partum generated antibodies to the E. coli, the mode of administration of the colostrum to the piglets is not limited thereto. The colostrum can be fed to the piglets by any suitable means including the direct oral administration--for example, by bottle feeding. It should also be noted that the piglets may be suckled by any previously immunized dam, such dam need not necessarily have been the piglet's own dam. The normal amount of colostrum ingested by a newborn piglet at its first suckling will generally be sufficient to provide the piglet with enough immunization to reduce the severity of any E. coli infection which it may acquire to a level from which an otherwise healthy piglet will recover from within one to six days. Needless to say, continued suckling for longer periods will increase the level of protection and thus reduce the likelihood of any E. coli infection appearing in the piglet.
In further challenge experiments, the challenge was made with another E. coli strain which, in cell agglutination tests, agglutinates in serum containing antibodies to E. coli 987-5 (ATCC 31346). This challenge strain, designated E. coli 74-5208 (ATCC 31347), has different "O" and "K" antigens. The degree of protection against this strain was not quite as great as against homologous (i.e., 987-5) challenge. Nevertheless, the thus challenged piglets had a substantially higher resistance level and survival rate than the piglets from unvaccinated dams.
It should be noted that, while the immunization of a newborn piglet by the feeding of colostrum from previously immunized pregnant dams is the especially preferred embodiment of the present invention, the invention is by no means limited thereto.
E. coli infection occurs, due to many different strains thereof, in different species of mammals. It has been found that E. coli species having Type I pili are responsible for human infections. Thus, the pili derived from related members of said group of species will provide protecting antibodies in a system into which they are administered.
EXAMPLE I
Preparation of Escherichia Coli Pili
E. coli somatic pili from pre-determined strains (74-5208 (ATCC 31347) and 987-5 (ATTC 31346)) were purified by crystallization with magnesium ion and solubilization of the crystals in its absence.
A culture prepared by resuspending piliated phase colonies growing on blood agar base medium in a liquid glucose-yeast extract-tryptone medium was used to inoculate trays containing the same gross medium solidified with agar. After overnight incubation at 37° C., the confluent bacterial grown was suspended in 0.05 molar MOPS (morpholinopropanesulfonic acid) buffered saline (0.85%) pH 7.2. About twenty milliters of buffer was used to suspend the growth from one tray which dimensions were approximately 30 cm×40 cm. The resuspended growth was blended, 200 milliliters at a time, at 14,000 rpm for five minutes in the 400 milliliter cup of a Sorvall® OMNIMIXER in order to remove pili from the cells. Cells were then removed by centrifugation at 10,000 times G for twenty minutes and the supernatant liquid was retained. The pili were then crystallized by the addition of magnesium chloride (MgCl 2 ) to 0.1 molar. After the crystals formed, they were removed from suspension by centrifugation at 20,000 times G for sixty minutes, and the pellet was retained. The pellet containing the pilus crystals was redissolved in 0.01 molar MOPS buffer pH 7.2 (without saline). The suspension was clarified by centrifugation at 20,000 times G for sixty minutes and the supernatant liquid was retained. The cycle of crystallization, centrifugation, redissolution, and centrifugation was repeated two to four times to obtain the purified pilus suspension.
The strains of E. coli, 74-5208 and 987-5 have been deposited under ATCC numbers 31346 and 31347 respectively in the American type Culture Collection 12301 Parklawn Drive, Rockville, Md. 20852.
EXAMPLE II
Mode of Immunization
The vaccine and the mode of protecting newborn piglets was evaluated with a group of 17 pregnant sows. Nine sows were injected with pili and eight with vehicle. The vehicle utilized saline (0.85%) and formaldehyde (0.05%). The vaccine consisted of vehicle containing 0.5 mg of pili per ml of vehicle. E. coli 987-5 (ATCC 31346) and 74-5208 (ATCC 31347) pili were used. Each vaccinated sow received approximately 9 mg of pili per sow or a dosage circa 60 micrograms per kilogram. Injections were given subcutaneously in the flank at between 21 and 27 days and again 7 through 13 days before farrowing. No local or systemic toxic effects were noted. Blood samples were taken from all sows immediately before farrowing and 100 to 200 ml of colostrum drawn manually from each sow during parturition. These samples were used for the antibody tests set forth below. After parturition, the piglets were allowed to suckle their dams for 30 minutes before challenge.
EXAMPLE III
Preparation of Inocula for E. coli 987 and 74-5208
Inocula. A colony of heavily piliated 987 bacteria was picked from pure culture on blood agar plates and was inoculated into 10 ml starter cultures of Trypticase soy broth (TCSB). After incubating at 37° C. without shaking for 16 hours, 1 ml of starter culture was used to inoculate 1 liter Erlenmeyer flasks containing 500 ml TCSB. With 74-5208, the flasks were inoculated directly with small, translucent colonies of heavily piliated 74-5208 bacteria selected from pure cultures on sheep blood agar. After incubating the flasks at 37° C. for 18 to 22 hours without shaking, the bacteria were harvested by centrifugation at 7,000 times G for ten minutes. The pelleted bacteria were resuspended in half strength TCSB containing 10% glycerol at 10 times the challenge concentration. The two inocula were stored at -70° C. for up to seven months in aliquots containing enough inoculum for each litter.
EXAMPLE IV
Homologous Challenge (987 v. 987 )
At birth, pigs were separated from the gilts for 2-6 hours, until all were born. They were then weighed and returned to the gilts for 30 minutes and allowed to suckle. After this initial colostrum intake, each pig was inoculated intragastrically with strain 987. The stock inoculum was kept frozen at -70° C., in 10% glycerol and contained 5.4×10 8 viable bacteria per ml. Immediately before the inoculation of each litter, one vial containing 1 ml of the frozen inocula was thawed out and 0.25 ml of it was diluted in 15 ml of cold trypicase soy broth (TCSB). One ml of this TCSB dilution, containing about 9×10 6 viable bacteria, was added to an additional 10 ml of cold TCSB and inoculated into each pig intragastrically via stomach tube. This dose was chosen because preliminary experiments indicated it was an approximate LD 50 .
Results of Homologous Challenge
The vaccinated and non-vaccinated piglets were subjected to certain tests which are summarized in Table I below. The tests are as follows:
1. Intestinal colonization
2. Adhesion of bacteria to the ilial epithelium
3. Death
4. Diarrhea
5. Weight gain
TABLE I__________________________________________________________________________VACCINE EXPERIMENT IResponse of pigs, nursing vaccinated.sup.a and nonvaccinated giltsto challenge with enterotoxigenic E. coli 987 6 days after challenge 16 h after challenge Survivors Log.sub.10 E. coli/ Association Death/ Diarrhea/ Weight gainGroup Dam No. 10 cm ileum index total total gram/h__________________________________________________________________________Vaccinated 1 8.6 1.0 0/8 0/8 7.8 2 8.1 1.7 0/7 0/7 8.9 5 8.4 1.0 0/11 0/11 8.6 6 8.9 1.0 0/8 0/8 6.5 10 6.0 1.0 0/11 0/11 4.5 11 7.9 1.0 0/6 0/6 5.0 12 6.0 1.0 0/3 0/3 4.4 15 6.0 2.5 0/7 0/7 7.2 16 6.0 2.0 0/8 0/8 7.3 .sup.--X= 7.3.sup.b .sup.--X= 1.2 Σ = 0/69.sup.c Σ = 0/69 .sup.--X= 6.7Nonvaccinated 3 8.7 1.0 0/7 0/7 8.8 4 10.2 5.0 7/10 3/3 1.3 7 9.8 1.0 1/6 3/5 6.3 8 8.9 4.2 6/11 1/5 1.3 9 10.8 5.0 1/3 2/2 0.3 13 10.4 4.2 2/8 0/6 1.2 14 8.2 1.0 0/7 2/7 5.8 17 6.0 1.0 0/4 0/4 8.9 9.1 2.8 17/56 11/39 4.2t test P < .05 P < .05 P < .001 P < .001 P < .05__________________________________________________________________________ .sup.a Vaccinated with purified pili of E. coli strain 987; .sup.b Mean; .sup.c Total.
DISCUSSION OF RESULTS
1. Intestinal colonization
Sixteen hours after challenge, one piglet, selected as the weakest, from each litter was killed. Sections of the ileum of all test animals were removed and examined for the presence of E. coli bacteria. The results show that the piglets suckled by the non-immunized dams had viable bacteria of approximately two orders of magnitude more per 10 cm section of ileum than the piglets suckled by the vaccinated dams. It was also noted that the former group (three animals tested) showed richly piliated colonies of E. coli 987 while no such colonies were found in a similar number of test animals in the latter group.
2. Association Index
This test measured the degree of adhesion of the challenge strain to the ileal epithelium. Ileal sections were stained with antibody to E. coli 987 coupled with fluorescein. This material, when adhered to a substrate, will fluoresce in uv light.
The degree of adhesion is expressed on a scale of 0 through 5. The difference in association index of 1.6 units between the vaccinated and non-vaccinated test animals is statistically significant (p is less than 0.05).
3. Death
No deaths occurred in the vaccinated group. Approximately 30% of the non-immunized group died of colibacillosis during the first six days of life, most deaths occurring on the second and third days.
4. Diarrhea
It should be noted that the Table refers to surviving test animals showing symptoms of diarrhea six days after challenge. In observations made 16 hours after challenge, 56% of the immunized group had diarrhea, while 72% of the non-immunized had diarrhea. Nevertheless, it should be noted from the Table that the immunized group recovered rapidly, while six days after challenge 28% surviving non-immunized pigs still had diarrhea.
5. Weight gain
The rate of weight gain in grams per hour was substantially greater among the immunized piglets than the non-immunized piglets--significance here again being p is less than 0.05 (using the t test).
EXAMPLE V
Heterologous Challenge
Substantially in accordance with the foregoing challenge procedures, experiments were carried out to determine the in vivo immune relationship between two strains of the same pilus type--i.e. 987 (serotype 09:K103, 987-P:NM) and 74-5208 (serotype 0.20:K 101, 987-P:NM), and a third strain, having an exocellular proteinaceous appendage of a different K serotype--i.e, 431 (serotype 0101:K30, K99:NM). Pregnant sows were inoculated with placebo and pili from the piliated strains and the appendage protein from the third strain. The piglets were suckled to post-partum sows, and randomly selected piglets challenged with each of the foregoing strains.
The results show homologous and heterologous protection between 987-5 and 74-5208 and homologous protection between 431 challenge and 431 appendage protein, but not between the two groups. These results are summarized in the FIGURE which shows percentage of remaining pigs with diarrhea verses day after challenge for each vaccine-challenge strain group.
The serological (antigen/antigen) relationship is summarized in Table II below.
TABLE II__________________________________________________________________________SERUM AND COLOSTRUM ANTIBODY TITERS IN NON-IMMUNIZED,987-5 PILUS IMMUNIZED AND 431 IMMUNIZED PREGNANT SOWSCell agglutination titers. Two-fold serumdilution series. One assay. Geometric mean of 6sows in each group 1st bleeding cells used (pre- ColostralImmunization for assay immunizing) 2nd bleeding 3rd bleeding whey__________________________________________________________________________ 987-5 3.0 4.0 4.6 3.2None 74-5208(Saline- (987 pili) 3.0 3.0 2.6 4.0Formaldehyde) 431 18.4 12.1 12.1 10.6987-5 puri- 987-5 3.5 128.0 388.0 2,352.5fied pili in 74-5208 7.0 512.0 1024.0 2,352.5saline- (987 pili)formaldehyde 431 16.0 10.6 36.8 73.5431 purified 987-5 3.5 4.5 5.0 8.0antigen* 3.5 5.7 3.6 6.1saline- (987 pili)formaldehyde(protein-appendage) 431 16.0 322.5 456.1 >4,096__________________________________________________________________________
A similar comparison to that of Table II above was performed which showed that the administration of pili to pregnant sows had no effect on the serum level of the "O" antigen, one of the other E. coli antigens. The results are set forth in Table III below.
The results of this "O" antigen experiment support the position that the pili are responsible for the immunity conferred against challenge by piliated organisms of similar pilus serotype.
TABLE III__________________________________________________________________________VACCINE EXPERIMENT IMEANS AND RANGES OF GROUPED E. COLI 987 0 ANTIGEN TUBEAGGLUTINATION TITERS OF SOW SERA AND COLOSTRAL WHEY Pre-immuneBody Fluid and/or Ratio ofAssayed Statistic Non-immune Post-immune Post-immune to Pre-immune__________________________________________________________________________Serum Geometric Mean* 44 69 1.6 Range 26-72 33-148 1.0-2.6 Log Mean ± 2 S-x 1.64 ± 0.22 1.84 ± 0.33 0.20 ± 0.21Colostral Geometric Mean* 191 219 1.1Whey Range 91-398 145-331 0.7-1.8 Log Mean ± 2 S-x 2.28 ± 0.32 2.34 ± 0.18 0.06 ± 0.20**__________________________________________________________________________ *In calculating the geometric mean a titer of less than 10, the lowest dilution used, is taken to be 5. **± Value is twice the standard error of the difference of the means o the logs of titers computed from the formula ##STR1##
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There is provided a vaccine material capable of providing a substantial level of protection against infection by enterotoxogenic organisms of Escherichia coli. The protecting means comprises pili of the infecting organism. The protection is given either by administering the pili directly to the subject to be protected or to a pregnant female where protection of the newborn is desired. In the case of piglets, where there is substantially no transplacental transfer of immunity from mother to offspring, the pili are administered to mothers, who are then caused to feed the offspring to be protected, whereby the immunization is transferred via the colostrum of the mother.
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BACKGROUND OF THE INVENTION
This invention relates to motor-driven pumps; more particularly the invention relates to a portable pumping system having capability for interchanging the driving source by utilizing a self-powered clutch for coupling between a reciprocable pump and any of a plurality of motor drive devices. The invention finds particular utility in portable pumping systems for which an electrical drive motor may be interchangeably used with an internal combustion drive motor, when external electrical power is not available. In such situations, the invention supplies its own electrical power needs to enable the drive motor to be efficiently coupled to a pumping system.
Prior art devices have included electrically-driven clutch assemblies in a common housing with an electrical generator; for example, U.S. Pat. No. 4,967,887, issued Nov. 6, 1990, discloses a magnetic particle clutch contained in the same housing as a permanent magnet generator, wherein the casing of the clutch is connected to a motor drive shaft and the rotor or disk of the clutch is connected to a load, and the rotor of the generator is also carried by the clutch casing; the generator produces an output voltage to power control circuitry for controlling the engagement of the clutch. The purpose of the patented invention is to provide an adjustable "soft start" to slowly bring the rotational speed of the load in synchronism with the speed of the drive motor.
In motor-driven pumping systems there is a need to control the action of the pump in response to the liquid pressure of the material being pumped. One approach, which has been used when an electrical motor is used to drive a pump, is to place a liquid pressure switch in the liquid delivery line and connect the switch to the electrical motor. When the liquid pressure reaches a predetermined level, the switch actuates and shuts off the power to the motor, thereby shutting down the pump. However, this approach does not work when an internal combustion engine is used to drive the pump, for the irregular stopping and starting of an internal combustion engine is an impractical solution to the problem. In this case, some form of clutch mechanism must be used so that the internal combustion engine may remain operating while the pump becomes disengaged from the engine.
It is desirable to provide a pumping system which may be interchangeably connected to either an electrical drive motor or to an internal combustion engine. Further, it is desirable that the motor control mechanism and power source be a part of the pumping system so that connection to the drive source can be expeditiously accomplished by a simple mechanical connection. This approach enables the pumping system to be manufactured separately from the drive mechanism without regard to the particular drive mechanism which might be selected for particular applications, and the drive motor/pump connection may be interchangeably made in the field, based upon the needs at the time.
SUMMARY OF THE INVENTION
The invention comprises a portable wheeled cart containing a first housing for an electrical clutch and generator assembly which is adapted for connection to a motor drive source and a second housing, connected to the first housing, for a reciprocable pump. An input-driven shaft is drivingly connected, via a belt and pulley or similar driving connection, to a motor drive source; a generator in the first housing has a permanent magnet rotor connected to the driven shaft and to a clutch plate of a magnetic clutch assembly. A fixed generator stator is connected, via a pressure switch, to the electrical field winding of the magnetic clutch assembly, and the armature element of the clutch assembly is connected to an output shaft which is geared to drive a crank arm of a reciprocable pump in the second housing.
It is a principal object and advantage of the invention to provide a self-powered clutch and pumping system for interchangeable connection to any of a variety of drive sources.
It is another object and advantage of the present invention to provide a pumping system which is self-contained and adaptable to connection to either an electrical or internal combustion driving source.
It is a further object and advantage of the invention to provide a pumping system having a pressure control switch which controls the operation of a magnetic clutch to selectively control the operation of the pump in the pumping system.
Other and further objects and advantages of the invention will become apparent from the following specification and drawings, and with reference to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of a pumping system of the type which finds utility for use with the present invention;
FIG. 2 shows an exploded view of the generator/clutch housing of the invention;
FIG. 3 shows a side cross section view of the clutch and pump drive housing of the invention; and
FIG. 4 shows a side cross section view of the generator/clutch housing of the invention;
FIG. 5 shows a schematic diagram of the electrical components of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an isometric view of a pumping system of the type which finds utility with the present invention. The components of the invention are all installed on a wheeled cart 10 which may be portably moved from one job site to another. The pumping system of FIG. 1 is typical of portable pumping systems utilized in the industrial paint spray industry, wherein equipment is moved to a job site for spraying at the job site. The cart 10 comprises a frame 12 upon which are mounted a pair of wheels 11 and a pair of support legs 13, 14. An adjustable handle 15 is attached to the frame 12 for moving the cart from place to place. A motor mounting assembly 16 is adapted to secure either a gasoline engine or an electric motor to the frame 12. An electrical grounding clamp 17 is affixed via a suitable cable to frame 12, and a clutch housing mount 18 also forms a part of frame 12.
In the embodiment of FIG. 1, a gasoline engine 20 is shown affixed to the motor mounting assembly 16; an electrical drive motor could equally well be attached to motor mounting assembly 16. The gasoline engine has an output drive pulley (not shown) which is protected by a guard housing 22, and is mechanically coupled to an input pulley 24 (see FIG. 2) which is a part of the clutch/generator assembly.
Clutch housing 30 is affixed to clutch housing mounting assembly 18, and pump drive housing 40 is bolted to clutch housing 30. A downwardly extending reciprocable pump 50 is attached to pump drive housing 40. An electrical housing 35 is affixed to the side of frame 12. An on/off switch 36 and an adjustable pressure switch 38 are each attached to electrical housing 35.
Pump 50 has an intake 52 which, during operation, is immersed into a suitable container of liquid. The pump output is connected via a hose 57 to a fluid inlet port in electrical housing 35. The electrical housing 35 has a fluid outlet port which is connected via a hose 53 to a filter 55, and thence to a delivery hose 56. Delivery hose 56 is connected to a spray gun 58.
FIG. 2 shows an exploded view of a portion of the pumping system of FIG. 1, wherein a part of cart 10 is shown in dotted outline. Clutch housing 30 contains all of the components shown in exploded view in FIG. 2. A pinion housing 32 is affixed to the end of clutch housing 30, and a pinion output shaft 34 projects outwardly from pinion housing 32. A drive shaft 25 projects from the rightward end of clutch housing 30, and a locknut 23 is keyed to shaft 25, and affixes input pulley 24 thereto. A generator rotor 26 is also affixed to shaft 25, as is clutch plate 28. A stator 27 is mounted in fixed position within housing 30, as is a field winding 29. Drive shaft 25 is supported at its inlet end within housing 30 by means of a bearing 31, and is supported at its outlet end by means of bearings seated within pinion 33. Pinion 33 has an outer toothed surface, and clutch armature 39 has a set of interior teeth which are engageable against the pinion teeth, wherein armature 39 is slidably engaged along the transverse length of the pinion teeth.
FIG. 3 shows an elevation view of clutch housing 30, pinion housing 32 and pump drive housing 40, with the pump drive assembly shown in partial cross section and breakaway. An inlet gear shaft 41 is supported by bearings in pinion housing 32 and further bearings in pump drive housing 40. An inlet toothed gear 42 is affixed to gear shaft 41, and is engaged to teeth on pinion shaft 34. An intermediate gear 43 is affixed to shaft 41 and is engaged to a drive gear 44. Drive gear 44 is affixed to a shaft 45 which is supported by bearings between pinion housing 32 and pump drive housing 40. Shaft 45 is connected to a crank arm 46, which is also connected to a connecting rod 47. Connecting rod 47 is slidably guided within a sleeve 48, and is coupled to a movable piston within pump 50. Pump 50, and its associated piston and valving assemblies are typical of reciprocable pump assemblies which are known in the prior art.
FIG. 4 shows a side elevation view in cross section, illustrating the clutch and generator assembly. Drive shaft 25 is supported by a bearing 31 which is pressed into the walls of clutch housing 30 at one of its ends, and is supported by bearings 59 and 60 which are inserted into an axial opening in pinion 33 at its other end. Pinion 33 is supported by a bearing 37 mounted in pinion housing 32. Stator 27 is affixed to the interior of housing 30 by means of fasteners 61, and one of the stator winding wires is grounded to the housing 30. Stator winding wire 64 (see FIG. 3) is connected through housing 30 to the interior of electrical housing 35. Field winding 29 is fixedly retained within housing 30, and the field winding wires 66, 67 are also routed outside of housing 30 into electrical housing 35 (see FIG. 3). Rotor 26 and clutch plate 28 are affixed together by fasteners, and are also together affixed to drive shaft 25. Therefore, rotation of shaft 25 causes simultaneous rotation of rotor 26 and clutch plate 28. Clutch armature 39 is slidably engaged to pinion 33 along an axis parallel to shaft 25, and is therefore rotatable therewith. The surface of clutch plate 28 which faces toward armature 39 has an annular recess which is filled with a non-magnetic cork material 28a. The cork material 28a facilitates the engagement of clutch plate 28 against armature 39 when field winding 29 is energized. The magnetic forces generated by field winding 29 cause an attractive force against armature 39, thereby slidably moving armature 39 toward the facing surface of clutch plate 28. The cork material 28a and the metal faces of clutch plate 28 engage against the facing surface of armature 39 and permits rotational engagement to occur between clutch plate 28 and armature 39 within a partial revolution of drive shaft 25, thereby ensuring that the clutch becomes fully engaged nearly instantaneously.
Pinion output shaft 34 projects through pinion housing 32, and is engageable with an inlet gear 42 as has been hereinbefore described. The interior recess of pinion 33 has a pair of lubricated bearings 59, 60, for receiving and supporting drive shaft 25. A relief port 57 provides a passage between the interior recess of pinion 33 and the outer end of pinion shaft 34. This relief port provides a passage for excess lubricant oils, so that excess lubricants which may build up within the interior of the recess for pinion 33 are bled outwardly into the adjoining pump drive housing, rather than inwardly into the generator/clutch housing. If such lubricants were to accumulate within the generator/clutch housing 30, they may degrade the operation of clutch plate 28.
FIG. 5 shows an electrical schematic diagram of the electrical components of the invention. The rotation of drive shaft 25 causes coincidental rotation of rotor 26, and rotor 26 has a pair of diametrically opposed permanent magnets 62, 63 affixed along the interior surface thereof. Permanent magnets 62, 63 rotate about stator winding 27, and induce a voltage across stator winding 27. Stator winding 27 is coupled to an on/off switch 36 via wire 64. Switch 36 is coupled to an adjustable pressure switch 38 and to a semiconductor triac 68. The adjustable pressure switch 38 is contained within electrical housing 35, and operates in conjunction with a Bourdon tube pressure sensor 49 to provide a switchable signal whenever the liquid pressure at the pump 50 outlet exceeds a predetermined value. The Bourdon tube pressure sensor 49 and adjustable pressure switch 39 is disclosed in U.S. Pat. No. 4,323,741, issued Apr. 6, 1982, and owned by the assignee of the present invention. When pressure switch 38 is closed it passes a signal to triac 68, thereby turning the triac on. This allows the alternating voltage across stator winding 27 to be conveyed to a full wave rectifier circuit 69. The output from rectifier circuit 69 is a DC voltage which is applied to field winding 29, thereby creating a magnetic field which causes clutch armature 39 to slidably move along pinion 33 toward clutch plate 28.
In operation, a suitable motor element, either an electrical motor or an internal combustion engine, is coupled via a belt to the input pulley 24. This causes drive shaft 25 to begin rotating, and thereby induces a voltage across stator winding 27. When the on/off switch 36 is actuated the voltage across the stator winding is applied to the pressure sensor switch 38, which is normally closed. The stator winding voltage is then applied via triac 68 and bridge circuit 69 to field winding 29, thereby causing a magnetic field to be developed. The magnetic field attracts the clutch armature 39 into engagement against clutch plate 28, and causes rotation of pinion 33 in synchronism with drive shaft 25. As pinion 33 rotates its pinion shaft 34 rotates, thereby creating the requisite mechanical rotation for operating the pump 50. Pump 50 delivers pressurized liquid to a spray gun 58 until the spray gun trigger is disengaged. When the spray gun trigger is disengaged the back pressure in the liquid delivery lines is eventually sensed by pressure sensor 49, causing pressure sensor switch 38 to become disengaged. The disengaging of pressure switch 38 removes the voltage from the field winding 29, thereby removing the magnetic attraction force against armature 39. This causes armature 39 to become disengaged from clutch plate 28 and removes the driving force for pump 50. Pump 50 ceases its reciprocable operation until a pressure drop occurs in the system, wherein the operation resumes according to the description above.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.
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A liquid pumping system adaptable for connection to either an electrical drive motor or an internal combustion engine, wherein a generator and clutch is coupled to the driving source, and a pressure sensing switch is connected to the generator rotor to selectively provide voltage to a rectifier circuit and field winding for the clutch. The energization of the field winding causes the clutch to actuate and thereby causes a mechanical coupling to a reciprocable pump for developing liquid pressure.
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TECHNICAL FIELD
[0001] The illustrative embodiments generally relate to a method and apparatus for primary driver verification.
BACKGROUND
[0002] Modern vehicle technologies offer unprecedented opportunities for customization. For instance, drivers can set their preferred seating positions, lumbar support, and steering wheel tilts, not to mention ever increasing on-board infotainment features ranging from center stack/cluster display appearance and radio station presets to the adaptive cruise control gap and lane-keeping aid sensitivity. The concept of customization can also be extended to information services and delivery, ranging from customized news coverage and music play lists to traffic information tailored to frequently visited POI (Points of Interest). While some of the features can be set once and remain valid for a long period of time, such as infotainment system's unit of measure (e.g., metric vs. English), others require frequent updates because of various changing factors.
[0003] One of the very important such factors is the driver. If the vehicle knows who is driving, it would be possible to tailor the vehicle seamlessly to the driver preferences.
SUMMARY
[0004] In a first illustrative embodiment, a system includes a processor configured to examine one or more vehicle settings having been changed after a driver enters a vehicle. Also, the processor is configured to compare the examined settings to settings associated with currently stored driver profiles and verify the driver as a previously stored primary vehicle driver based at least in part on the comparison.
[0005] In a second illustrative embodiment, a computer-implemented method includes examining one or more vehicle settings having been changed after a driver enters a vehicle. The method also includes comparing the examined settings to settings associated with currently stored driver profiles and verifying the driver as a previously stored primary vehicle driver based at least in part on the comparison.
[0006] In a third illustrative embodiment, a non-transitory computer-readable storage medium stores instructions that, when executed by a processor, cause the processor to perform the method including examining one or more vehicle settings having been changed after a driver enters a vehicle. The method also includes comparing the examined settings to settings associated with currently stored driver profiles and verifying the driver as a previously stored primary vehicle driver based at least in part on the comparison.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows an illustrative vehicle computing system;
[0008] FIG. 2 shows an illustrative process for driver profile creation;
[0009] FIG. 3 shows an illustrative process for data collection and updating;
[0010] FIG. 4 shows an illustrative process for driver verification; and
[0011] FIG. 5 shows another illustrative process for driver verification.
DETAILED DESCRIPTION
[0012] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0013] FIG. 1 illustrates an example block topology for a vehicle based computing system 1 (VCS) for a vehicle 31 . An example of such a vehicle-based computing system 1 is the SYNC system manufactured by THE FORD MOTOR COMPANY. A vehicle enabled with a vehicle-based computing system may contain a visual front end interface 4 located in the vehicle. The user may also be able to interact with the interface if it is provided, for example, with a touch sensitive screen. In another illustrative embodiment, the interaction occurs through, button presses, audible speech and speech synthesis.
[0014] In the illustrative embodiment 1 shown in FIG. 1 , a processor 3 controls at least some portion of the operation of the vehicle-based computing system. Provided within the vehicle, the processor allows onboard processing of commands and routines. Further, the processor is connected to both non-persistent 5 and persistent storage 7 . In this illustrative embodiment, the non-persistent storage is random access memory (RAM) and the persistent storage is a hard disk drive (HDD) or flash memory.
[0015] The processor is also provided with a number of different inputs allowing the user to interface with the processor. In this illustrative embodiment, a microphone 29 , an auxiliary input 25 (for input 33 ), a USB input 23 , a GPS input 24 and a BLUETOOTH input 15 are all provided. An input selector 51 is also provided, to allow a user to swap between various inputs. Input to both the microphone and the auxiliary connector is converted from analog to digital by a converter 27 before being passed to the processor. Although not shown, numerous of the vehicle components and auxiliary components in communication with the VCS may use a vehicle network (such as, but not limited to, a CAN bus) to pass data to and from the VCS (or components thereof).
[0016] Outputs to the system can include, but are not limited to, a visual display 4 and a speaker 13 or stereo system output. The speaker is connected to an amplifier 11 and receives its signal from the processor 3 through a digital-to-analog converter 9 . Output can also be made to a remote BLUETOOTH device such as PND 54 or a USB device such as vehicle navigation device 60 along the bi-directional data streams shown at 19 and 21 respectively.
[0017] In one illustrative embodiment, the system 1 uses the BLUETOOTH transceiver 15 to communicate 17 with a user's nomadic device 53 (e.g., cell phone, smart phone, PDA, or any other device having wireless remote network connectivity). The nomadic device can then be used to communicate 59 with a network 61 outside the vehicle 31 through, for example, communication 55 with a cellular tower 57 . In some embodiments, tower 57 may be a WiFi access point.
[0018] Exemplary communication between the nomadic device and the BLUETOOTH transceiver is represented by signal 14 .
[0019] Pairing a nomadic device 53 and the BLUETOOTH transceiver 15 can be instructed through a button 52 or similar input. Accordingly, the CPU is instructed that the onboard BLUETOOTH transceiver will be paired with a BLUETOOTH transceiver in a nomadic device.
[0020] Data may be communicated between CPU 3 and network 61 utilizing, for example, a data-plan, data over voice, or DTMF tones associated with nomadic device 53 . Alternatively, it may be desirable to include an onboard modem 63 having antenna 18 in order to communicate 16 data between CPU 3 and network 61 over the voice band. The nomadic device 53 can then be used to communicate 59 with a network 61 outside the vehicle 31 through, for example, communication 55 with a cellular tower 57 . In some embodiments, the modem 63 may establish communication 20 with the tower 57 for communicating with network 61 . As a non-limiting example, modem 63 may be a USB cellular modem and communication 20 may be cellular communication.
[0021] In one illustrative embodiment, the processor is provided with an operating system including an API to communicate with modem application software. The modem application software may access an embedded module or firmware on the BLUETOOTH transceiver to complete wireless communication with a remote BLUETOOTH transceiver (such as that found in a nomadic device). Bluetooth is a subset of the IEEE 802 PAN (personal area network) protocols. IEEE 802 LAN (local area network) protocols include WiFi and have considerable cross-functionality with IEEE 802 PAN. Both are suitable for wireless communication within a vehicle. Another communication means that can be used in this realm is free-space optical communication (such as IrDA) and non-standardized consumer IR protocols.
[0022] In another embodiment, nomadic device 53 includes a modem for voice band or broadband data communication. In the data-over-voice embodiment, a technique known as frequency division multiplexing may be implemented when the owner of the nomadic device can talk over the device while data is being transferred. At other times, when the owner is not using the device, the data transfer can use the whole bandwidth (300 Hz to 3.4 kHz in one example). While frequency division multiplexing may be common for analog cellular communication between the vehicle and the internet, and is still used, it has been largely replaced by hybrids of with Code Domain Multiple Access (CDMA), Time Domain Multiple Access (TDMA), Space-Domain Multiple Access (SDMA) for digital cellular communication. These are all ITU IMT-2000 (3G) compliant standards and offer data rates up to 2 mbs for stationary or walking users and 385 kbs for users in a moving vehicle. 3G standards are now being replaced by IMT-Advanced (4G) which offers 100 mbs for users in a vehicle and 1 gbs for stationary users. If the user has a data-plan associated with the nomadic device, it is possible that the data-plan allows for broad-band transmission and the system could use a much wider bandwidth (speeding up data transfer). In still another embodiment, nomadic device 53 is replaced with a cellular communication device (not shown) that is installed to vehicle 31 . In yet another embodiment, the ND 53 may be a wireless local area network (LAN) device capable of communication over, for example (and without limitation), an 802.11g network (i.e., WiFi) or a WiMax network.
[0023] In one embodiment, incoming data can be passed through the nomadic device via a data-over-voice or data-plan, through the onboard BLUETOOTH transceiver and into the vehicle's internal processor 3 . In the case of certain temporary data, for example, the data can be stored on the HDD or other storage media 7 until such time as the data is no longer needed.
[0024] Additional sources that may interface with the vehicle include a personal navigation device 54 , having, for example, a USB connection 56 and/or an antenna 58 , a vehicle navigation device 60 having a USB 62 or other connection, an onboard GPS device 24 , or remote navigation system (not shown) having connectivity to network 61 . USB is one of a class of serial networking protocols. IEEE 1394 (firewire), EIA (Electronics Industry Association) serial protocols, IEEE 1284 (Centronics Port), S/PDIF (Sony/Philips Digital Interconnect Format) and USB-IF (USB Implementers Forum) form the backbone of the device-device serial standards. Most of the protocols can be implemented for either electrical or optical communication.
[0025] Further, the CPU could be in communication with a variety of other auxiliary devices 65 . These devices can be connected through a wireless 67 or wired 69 connection. Auxiliary device 65 may include, but are not limited to, personal media players, wireless health devices, portable computers, and the like.
[0026] Also, or alternatively, the CPU could be connected to a vehicle based wireless router 73 , using for example a WiFi 71 transceiver. This could allow the CPU to connect to remote networks in range of the local router 73 .
[0027] In addition to having exemplary processes executed by a vehicle computing system located in a vehicle, in certain embodiments, the exemplary processes may be executed by a computing system in communication with a vehicle computing system. Such a system may include, but is not limited to, a wireless device (e.g., and without limitation, a mobile phone) or a remote computing system (e.g., and without limitation, a server) connected through the wireless device. Collectively, such systems may be referred to as vehicle associated computing systems (VACS). In certain embodiments particular components of the VACS may perform particular portions of a process depending on the particular implementation of the system. By way of example and not limitation, if a process has a step of sending or receiving information with a paired wireless device, then it is likely that the wireless device is not performing the process, since the wireless device would not “send and receive” information with itself. One of ordinary skill in the art will understand when it is inappropriate to apply a particular VACS to a given solution. In all solutions, it is contemplated that at least the vehicle computing system (VCS) located within the vehicle itself is capable of performing the exemplary processes.
[0028] Modern vehicle technologies offer unprecedented opportunities for customization. For instance, drivers can set their preferred seating positions, lumbar support, steering wheel tilts, center/stack cluster appearance, radio station presets, adaptive cruise control gap, lane-keeping aid sensitivity, etc. Customization can also be extended to information services and delivery, ranging from customized news coverage and music play lists to traffic information tailored to frequently visited points of interest (POIs). While some of the features can be set once and remain valid for a long period of time, others may require frequent changes due to various changing factors.
[0029] One common “changing factor” is the vehicle driver. If the vehicle knows who is driving, it would be possible to tailor the vehicle seamlessly to the driver preferences. For instance, as soon as the driver sits down in the vehicle and starts the engine, the vehicle could adjust the seat position, pedal positions, steering wheel tilt, climate control settings, driving mode, radio station presets, etc., based on registered driver preferences. In such a case, the driver may not even need to press a button or enter a request for settings changes, the vehicle “knows” who is driving and prepares the environment as the driver prefers.
[0030] When a vehicle is first delivered to a customer, the driver can be asked a few questions in an initialization phase. These can include, for example, whether or not to store presets and preferences, and for a profile name. The profile will correspond to a default driver.
[0031] In one embodiment, the vehicle will have one or more “primary” drivers. These include people who commonly use the vehicle. The vehicle also may have one or more secondary drivers, which correspond to people who may, for example, occasionally borrow the vehicle. In this example, the vehicle is able to use the illustrative embodiments to verify a member of the primary group and provide settings based on that verification.
[0032] After an initialization phase, data can be collected continuously during the usage of the vehicle for development of user profiles. This data can not only be used to set the vehicle to the desired preferences when a driver is verified, but the data itself can be used to verify a driver, as shown in the illustrative embodiments. Data can include, but is not limited to, seat positions, steering wheel tilt, mirror positions, pedal positions, driver weight, climate control settings, climate control settings, radio station tuning, route selection, operation data, shifting styles, driver voice signature, facial images, GPS data (preferences, predictions, etc.), driver smartphone controls, etc.
[0033] FIG. 2 shows an illustrative process for driver profile creation. In this example, a new driver may be added to the vehicle. If a driver profile doesn't exist, or if the driver isn't recognized by the vehicle (after a certain measure of analysis, for example), the process may attempt to create a new profile 201 .
[0034] First, in this example, the process queries the driver to determine if the present driver is a primary driver of the vehicle. The driver doesn't necessarily need to benefit from the vehicle remembering setting information. In this illustrative example, the process determines if there is any primary driver set at all 203 . If there isn't, the process initiates a user profile 209 . Similarly, even if there is a primary driver, the process asks if the driver is an additional primary driver 205 . If so, the process also initiates a profile for the new primary driver.
[0035] If the driver is not a primary driver, the process may gather data for a secondary driver 207 . In this example, if a secondary driver is using the vehicle, the process may provide a “common” set of interfaces and vehicle environmental settings. Since the settings are for general use by vehicle borrowers, the process may gather data from secondary drivers to provide a secondary profile that is representative of the aggregate choices of secondary users. In another example, the process may simply provide a factory preset secondary setting, for example.
[0036] In the event of a primary (or in this case, secondary) driver, the process may collect some basic data about the driver 211 . This can be as simple as asking the driver to provide a profile identification. It could also include, for example, recording seat weight sensor data, recording facial profile data, etc. This could be especially useful with respect to primary drivers.
[0037] Once any initialization data has been gathered, the process may begin data gathering 213 , to record information based on what the driver enters/changes during a trip.
[0038] FIG. 3 shows an illustrative process for data collection and updating. As previously mentioned, the processes described herein may gather and adjust vehicle settings to a variety of driver-preferred standards. Since this data may change over time, even for a particular driver, the process may need to track changes in the data. In this example, both “fixed” and variable settings are considered.
[0039] The fixed settings are not technically “fixed,” but are settings that are typically left alone once set. These include, but are not limited to, seat settings, mirror settings, radio presets, etc. The variable settings, on the other hand, correspond to things that commonly change over a drive, such as radio volume, temperature settings, etc. Even if these variables commonly change over a drive, they may have typical settings in the average, or may change in a predictable manner.
[0040] Once data tracking has begun 301 , the process determines if a change has been detected to a fixed setting 303 or a variable setting 313 . If no discernible change has been made to either setting, the process will continue to monitor for changes to either setting type.
[0041] If a change to a fixed setting, for example, has been detected 303 , the process determines if a time period of some predetermined amount has elapsed 305 . Since the setting could have been briefly changed, or the change could be detected during the process of changing the setting (but the setting having not yet reached a final setting), the process may not record/register a detected change until after a predetermined time period has passed.
[0042] While the time is passing, the process may also determine if the detected change remains 307 . In this manner, if the process detects a change in progress, but that has not reached a final setting, then the change (to the intermediate setting) should not remain over the pre-determined period of time. Accordingly, until the change reaches a setting for which it remains for some period of time, the process will ignore the intermediate changes and continue to look for a finalization of the change.
[0043] If the change has remained for the predetermined period of time, the process has to determine whether or not to update the setting 309 . This could be a decision of the vehicle system itself, or it could be a result of asking a driver if the new setting should be saved to replace the old setting. If the update has been requested/decided on, the process will change the setting 311 . In some cases, the process may determine that an aggregate setting should be used, in other cases the process can merely adopt the new setting.
[0044] In another case, the process determines if a variable setting (such as volume) has changed. Variable settings are often affected by vehicle/environmental context. For example, a loud environment could cause a user to increase radio volume. A cold environment could cause a user to increase temperature. Since the context may have bearing on the variable, the process may track and even record the context so that the vehicle can apply certain changes based on correspondences to environment.
[0045] Once context data has been gathered (either generally all available context data, or data relating to the changed variable), the process again attempts to determine if a predetermined time period has elapsed 317 . As with the fixed settings, it may only be desirable to record a change in data if some time period has elapsed, although the time period may be different for the fixed versus variable settings. If the time period has not elapsed, and the setting still remains 319 , the process continues waiting for the predetermined amount of time to elapse. If, however, the setting changes, before the time is up, the process continues monitoring for changes to a setting.
[0046] As with the fixed settings, if the time period elapses and the setting has been maintained, the process must decide whether an update is in order. If the update is appropriate, the process will update the settings and make any adjustments to context variables associated with those settings. Context variables can also be associated with fixed settings, although it is more likely that they will be associated with these variable settings, since these are elements that commonly change over the course of a journey, often in reaction to an environmental event.
[0047] FIG. 4 shows an illustrative process for driver verification. In this illustrative example, the process describes a primary driver verification system (PDVS) 407 . The PDVS tracks the driver interaction with interior features, settings, vehicle preferences and verifies who the driver is based on one or more decision systems and/or algorithms.
[0048] Once the driver has been verified, the PDVS can set vehicle preferences with a relative degree of confidence. The PDVS consists of a number of primary driver verifiers PDVs. The PDVs are collected from a number of information services, such as, but not limited to, driver and interior features 401 , vehicle response 403 , additional driver based information sources 405 , etc.
[0049] Example PDVs include, but are not limited to Driver Positioning Verifier (DPV) 409 , Driver Interior Setting Verifier (DISV) 411 , Driver Style Verifier (DSV) 413 , etc. 415 . These PDVs are based on data gathered from the numerous vehicle systems and feedback processes provided to the vehicle. Any point where the driver interacts with the vehicle, data can be gathered and used for driver verification if appropriate.
[0050] The output (or settings of) the various PDVs aggregate to determine which of the primary drivers are operating the vehicle 417 . In some cases, depending on the number of drivers and inputs, the aggregation determination could be determined after only one or two variable inputs. If, for example, there were only two drivers of a vehicle, there are likely a number of easily discernible differences. On the other hand, if the two drives were twins of relatively similar weights, for example, the process may require more inputs to determine which of the twins is driving at a given time.
[0051] Once a particular driver has been verified, the process can then proceed with feature and function customization based on the preferences of the verified driver. The process can also monitor and update changes to fixed or variable settings.
[0052] FIG. 5 shows another illustrative process for driver verification. This process describes in greater detail one exemplary manner for verifying a driver. In this example, the process uses one or more DPV inputs such as, but not limited to, memory seat positions, steering wheel tilt, mirror positions, pedal positions, etc. Once a drive has begun, the process can gather and analyze data 501 . Once the drive has begun 501 , it is assumed that the seats and mirrors are likely in the proper position to use one or more of these as driver verification data points.
[0053] In one example, a seat position could be used as an example for driver verification. For example, over a period of time, it could be observed that driver A has a mean seat position of 30 cm with a standard deviation of 2 cm, while driver B has a mean seat position of 40 cm with a standard deviation of 1.5 cm. Similar likelihood and frequency distribution data may be computed for additional DPVs. The likelihood of various DPVs for a particular driver can be combined to provide a DPV input component to a verification equation 503.
[0054] Another source of verification data may include driver interior setting verifiers (DISVs). These examples include, for instance, climate control settings, radio station tuning, etc. For example, if climate temperature targets were used for verification, climate target setting data and probability data may be gathered 505 . This can be compared to data gathered over a number of drive cycles.
[0055] For example, driver A may have a mean target setting of 70 degrees with a standard deviation of 2 degrees, and driver B may have a mean target setting of 68 degrees with a standard deviation of 3 degrees.
[0056] Yet another piece/pieces of usable information may include driving style verifiers (DSVs). These can be gathered 507 based on observed driving behavior, such as braking habits, acceleration habits, etc. For any given feature, the feature dependent PDV aggregation to obtain the overall likelihood of a verified driver may be given by:
[0000]
PDV
j
=
∑
i
=
1
N
w
i
y
i
∑
i
=
1
N
w
i
[0057] Where:
[0058] j=number of drivers to verify (e.g., number of primary drivers);
[0059] PDV j =the aggregated likelihood of a driver verified value (0-1)
[0060] N=the number of PDVs
[0061] y i =PDV values for a potential driver
[0062] w i =weight attributed to each PDV indicator
[0063] For example, using the exemplary PDVs described herein, DPV, DISV and DSV, along with 2-stage driver verification (A,B; where A and B are the potential drivers), the likelihood of the driver being driver A is given by:
[0000]
PDV
A
=
DPV
A
w
DPV
+
DISV
A
w
DISV
+
DSV
A
w
DSV
w
DPV
+
w
DISV
+
w
DSV
[0064] and the likelihood of the driver being driver B is given by:
[0000]
PDV
B
=
DPV
B
w
DPV
+
DISV
B
w
DISV
+
DSV
B
w
DSV
w
DPV
+
w
DISV
+
w
DSV
[0065] When a tunable minimum PDV threshold is achieved, the particular driver can be verified based on the highest PDV value. Feature, function settings and recommendations are then provided based on the verified driver. The illustrative embodiments can modify a number of vehicle settings and HMI settings, including, but not limited to, HMI displays (radio presets, for example), physical system settings (seat/wheel/mirror presets), airbag deployment pressure, adaptive vehicle modes, climate controls, etc.
[0066] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
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A system includes a processor configured to examine one or more vehicle settings having been changed after a driver enters a vehicle. Also, the processor is configured to compare the examined settings to settings associated with currently stored driver profiles and verify the driver as a previously stored primary vehicle driver based at least in part on the comparison.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application Ser. No. 13/511,337 filed on Jun. 15, 2012, which is a U.S. National Stage application based on International Patent Application No. PCT/SE2010/000273 filed on Nov. 12, 2010, which claims priority to Swedish Patent Application No. 0901479-6 filed on Nov. 24, 2009, the entire content of all three of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention generally relates to the field of packaging technology. More particularly, the invention relates to a device for facilitating folding of a container, an apparatus comprising the device, and a method for folding the container.
BACKGROUND DISCUSSION
Background of the Invention
[0003] An apparatus for packaging pourable food in containers comprise a number of steps. In short, such an apparatus may comprise the steps of forming a tube of a web of packaging material, filling said tube with the pourable food, forming containers from the tube by transversally sealing and cutting the tube, and folding the containers to their final form. Further, the folding step can be divided into a number of sub-steps. For example, during a first folding sub-step performed in association to the sealing and cutting step, a section of the containers being sealed may be formed to have a rectangular cross-section. In later folding sub-steps, the container may be folded in such a way that a rectangular base is achieved, e.g. by folding the outer ends of the sealing end into the middle of the sealing end.
[0004] In order to reduce the risk of having leaking containers it is important that the folding is made correctly, since an improper folding can create tensions in the containers, which can result in leaking containers. This is especially important if the packaging material comprises several layers, such as a carton layer, plastic layers and an aluminum foil.
[0005] In order to facilitate the folding and thus reduce the risk of improper folding, packaging material having creasing lines may be used. However, although packaging material provided with creasing lines is used, there is still a risk that the folding is made improperly.
SUMMARY
[0006] In view of the above, an objective of the invention is to solve or at least reduce the problems discussed above. In particular, an objective is to improve a filling machine in such a way that the number of improperly folded containers is reduced.
[0007] The general idea is to flatten a first and a second end portion of a sealed end of a container by two flattening elements such that later folding of the first and second end portion towards a middle portion, placed between the first and second end portion, is facilitated.
[0008] According to a first aspect a device is provided. The device comprises a first flattening element and a second flattening element arranged to flatten a first end portion and a second end portion of a sealed end of a container, respectively, such that folding of the first end portion and the second end portion towards a middle portion placed between the first end portion and the second end portion is facilitated.
[0009] The first flattening element and the second flattening element may be a first flattening wheel and a second flattening wheel, respectively.
[0010] The device may further comprise a conveyor belt, placed between the first flattening element and the second flattening element, arranged to hold the middle section of the sealed end down folded.
[0011] Further, a speed of the conveyor belt may be equal to a speed of the first flattening element and the second flattening element.
[0012] An advantage of having the same speed for the flattening elements and the conveyor belt is that less shear stress is generated in the container.
[0013] Moreover, the conveyor belt, the first flattening element and the second flattening element may have a common driving shaft.
[0014] The first flattening element and the second flattening element may have a rubber coating. Alternatively, the first flattening element and the second flattening element may be made of rubber.
[0015] According to a second aspect an apparatus is provided. The apparatus comprises a conveyor for transporting containers in an upright position, a plate adapted to direct a sealed end of said container into a down folded position during transportation of said container by said conveyor, and a device according to the first aspect.
[0016] A speed of the first flattening element and the second flattening element of the device may be equal to a speed of the conveyor.
[0017] The apparatus may further comprise rails adapted to direct a first end portion and a second end portion of the sealed end such that the first end portion and the second end portion are bended substantially 90 degrees in relation to a middle portion of the sealed end during transportation of the container by the conveyor.
[0018] The conveyor belt of the device may be arranged to hold the middle portion of the sealed end during the first end portion and the second end portion are bended substantially 90 degrees in relation to the middle portion by the rails.
[0019] According to a third aspect a method for folding a container is provided. The method comprises flattening a first end portion and a second end portion of a sealed end of said container, and folding the first end portion and the second end portion towards a middle portion of the sealed end.
[0020] The middle portion may be held down folded by a conveyor belt during the step of flattening the first end portion and the second end portion of the sealed end of the container.
[0021] Further, the step of folding the first end portion and the second end portion towards the middle portion of the sealed end may comprise the sub-step bending the first end portion and the second end portion substantially 90 degrees in relation to the middle portion while the middle portion is held in position by the conveyor belt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, wherein:
[0023] FIG. 1 a -1 d illustrate a container during four different folding sub-steps from a first side view, a second side view and seen from above.
[0024] FIG. 2 illustrates the final form of the container.
[0025] FIG. 3 illustrates an apparatus for folding containers.
[0026] FIG. 4 illustrates the apparatus in further detail.
[0027] FIG. 5 illustrates a side view of the apparatus.
[0028] FIG. 6 illustrates a top view of the apparatus.
[0029] FIG. 7 illustrates an improperly folded container.
[0030] FIG. 8 illustrates a device of the apparatus in further detail.
[0031] FIG. 9 illustrates a cross-section of the device.
DETAILED DESCRIPTION
[0032] After the steps of filling, sealing and cutting have been performed in a filling machine, a container 100 having a first sealing end 102 and a second sealing end 104 can be obtained, as illustrated in FIG. 1 a . During the filling step, a section 106 of the container 100 may be formed to have a rectangular cross-section.
[0033] Starting from the section 106 , the container 100 may be folded in a number of sub-steps such that a rectangular base is achieved. In a first folding sub-step the first sealing end 102 is down folded and pushed towards the section 106 , thereby achieving a substantially flat surface, as illustrated in FIG. 1 b . The surface may be divided in a first end portion 108 a , a second end portion 108 b and a middle portion 110 . The first end portion 108 a and the second end portion 108 b can be substantially triangular and the middle portion 110 can be substantially rectangular with the same size as the rectangular cross-section of the section 106 .
[0034] Then, in a pre-folding step, the first end portion 108 a and the second end portion 108 b can be flattened by flattening elements. An advantage of flattening the end portions 108 a , 108 b is that folding of the outer ends 108 a , 108 b towards the middle portion 110 is facilitated, and thereby that the risk of having folding lines not placed in the intersections between the outer ends and the middle portion is reduced.
[0035] In a next folding sub-step, the first end portion 108 a and the second end portion 108 b can be folded such that the first sealing end 102 is bended about 90 degrees in an intersection between the first end portion 108 a and the middle portion 110 , and in an intersection between the second end portion 108 b and the middle portion 110 , as illustrated in FIG. 1 c.
[0036] Finally, in the last folding sub-step, the first end portion 108 a and the second end portion 108 b can be folded inwardly towards the middle portion 110 , thereby forming a substantially rectangular base of the container 100 , also referred to as a bottom. As illustrated in FIG. 1 d , the first sealing end 102 can be bended about 180 degrees in the intersection between the first end portion 108 a and the middle portion 110 , and in the intersection between the second end portion 108 b and the middle portion 110 . By pressing the outer parts of the end portions 108 a , 108 b towards the middle portion 110 a more stable bottom may be achieved such that when the container 100 is standing with the bottom down, as illustrated in FIG. 2 , the inwardly folded first and second end portions 108 a , 108 b as well as the middle portion 110 are in contact with the underlaying surface. However, in order to illustrate the folding of the container 100 , no account has been taken to that the end portions 108 a , 108 b are pressed towards the middle portion 110 in FIG. 1 c and FIG. 1 d.
[0037] FIG. 3 illustrates an apparatus 200 for folding containers 100 , as illustrated in FIG. 1 a , into containers having a rectangular base as illustrated in FIG. 1 d and FIG. 2 .
[0038] The container 100 can be fed from the filling machine to the apparatus 200 via a conveyor belt. When reaching the apparatus 200 the container 100 can be introduced with the second sealing end 104 first into a wedge-shaped pocket formed between two consecutive carriers of a conveyor 202 running in a conveyor direction CD. During transportation the first sealing end 102 can be down folded by a plate 204 . The plate 204 can be mounted such that a distance between the plate 204 and the conveyor 202 diminishes successively as the container 100 is transported along the conveyor 202 . An effect of this is that the containers can successively be transformed from the shape illustrated in FIG. 1 a to a shape illustrated in FIG. 1 b.
[0039] Next, the container can reach a first flattening wheel 302 a arranged to flatten the first end portion 108 a of the first sealing end 102 and a second flattening wheel 302 b arranged to flatten the second end portion 108 b of the first sealing end 102 . The flattening wheels 302 a and 302 b are arranged rotatably around a horizontal axis perpendicular to the conveyor direction CD. In this way the flattening wheels 302 a and 302 b may apply a higher downward pressure, since their rotational movement follows the conveyor direction CD, diminishing risk of interference with the conveyor direction CD at higher pressures. In order to make sure that the first sealing end 102 is kept in position, a conveyor belt 304 placed between the first flattening wheel 302 a and the second flattening wheel 302 b can be used. As illustrated in FIG. 3 , the first flattening wheel 302 a , the second flattening wheel 302 b and the conveyor belt 304 may rotate around a common rotational axis RA 1 . The conveyor belt 304 may further rotate around a rotational axis RA 2 .
[0040] An advantage of flattening the end portions 108 a , 108 b is that if any product, with which the container is filled, is present in the end portions this can be moved to the middle portion 110 , which makes it possible to achieve thinner and more well-defined end portions. Thinner end portions, in turn, provide for that the folding of the end portions towards the middle portion 110 is facilitated.
[0041] Another advantage, if a speed of the first flattening wheel 302 a and the second flattening wheel 302 b is equal to a speed of the conveyor 202 , is that the first and second end portions 108 a , 108 b may be flattened during transportation without generating unwanted shear stress in the container 100 .
[0042] Next, the end portions 108 a , 108 b can be folded upwards 90 degrees, as illustrated FIG. 1 c , by rails 206 directing the end portions 108 a , 108 b as the containers are transported by the conveyor 202 . In order to control that the folding is made as intended, that is, in the intersection between the end portion 108 a and the middle portion 110 , and the intersection between the end portion 108 b and the middle portion 110 , the middle portion 110 can be held in correct position by the conveyor belt 304 . Thus, the outer ends of the conveyor belt 304 provide for that the folding is made as intended. In order to reduce the risk of deformation of the containers, a speed of the conveyor 202 may be equal to a speed of the conveyor belt 304 .
[0043] After the end portions 108 a , 108 b have been folded upwards about 90 degrees, heating elements 208 can heat the end portions 108 a , 108 b as they are transported by the conveyor 202 , thereby melting a plastic layer of the containers.
[0044] Then, in a final folding sub-step, the end portions 108 a , 108 b can be folded inwardly and pressed towards the middle portion 110 . Due to the heating of the end portions 108 a , 108 b , these attach to the middle portion 110 . As the melted plastic layer is cooled down the end portions 108 a , 108 b are permanently attached to the middle portion 110 . Further, by pressing the end portions 108 a , 108 b towards the middle portion 110 , a rectangular base can be formed such that when the container is standing with the rectangular base down the container rests on the outer end portions 108 a , 108 b and the middle portion 110 .
[0045] The first and second flattening wheels 302 a , 302 b may be attached by screws to a first cogwheel of the conveyor belt 304 , as illustrated in FIG. 4 , thereby making it easy to replace the first and second flattening wheels 302 a , 302 b.
[0046] FIG. 5 illustrates a side view of the apparatus 200 and FIG. 6 illustrates a top view of the apparatus 200 . When the end portions 108 a , 108 b have been flattened by the flattening wheels 302 a , 302 b the rails 206 can fold the end portions 108 a , 108 b upwards about 90 degrees. As described above, by holding the middle portion 110 in position by the conveyor belt 304 , the risk of improper folding can be reduced. Further, as illustrated, rails having the function as counter elements may be provided in association to the flattening wheels.
[0047] One type of improper folding of the container is illustrated in FIG. 7 . Such an improper folding may arise if for instance a fixed plate is used instead of a conveyor belt 304 . More particularly, by having a fixed plate, friction may arise between the container 100 and the fixed plate, thereby holding back the middle portion 110 , but not the outer portions 108 a , 108 b , thereby giving rise to an improper folding and unwanted stress in the container 100 , and possibly a leaking container.
[0048] In order to drive the first and second flattening wheels 302 a , 302 b , and the conveyor belt 304 , a driving shaft 306 may be used, as illustrated in FIG. 8 and FIG. 9 . The driving shaft 306 may be common to the first and second flattening wheels 302 a , 302 b and the conveyor belt 304 . The driving shaft 306 may be connected to an engine (not shown). A device 300 comprising the first and second flattening wheels 302 a , 302 b , the conveyor belt 304 and the driving shaft 306 may thus form part of the apparatus 200 .
[0049] The first and second flattening wheels 302 a , 302 b may be provided with rubber coatings. The rubber coatings may be resistant to hydrogen peroxide, which may be used to sterilise the packaging material. Alternatively, the first and second flattening wheels 302 a , 302 b may be made of solid rubber.
[0050] The conveyor belt 304 may also be provided with a rubber coating resistent to hydrogen peroxide.
[0051] Instead of using the first and second flattening wheel 304 a , 304 b , a first and second flattening conveyor belt may be used. The first and second flattening conveyor belt may be shorter than the conveyor belt 304 , such that the outer ends of the conveyor belt 304 can be used when folding the first and second end portions 108 a , 108 b upwards as described above.
[0052] Although the apparatus 200 and the device 300 are described with respect to containers having a rectangular base and an unfolded sealing end as a top, the scope of the invention is generally applicable to containers 100 having a sealed end 102 comprising a first end portion 108 a , a second end portion 108 b and a middle portion 110 , where the first and second end portions 108 a , 108 b are inwardly folded and attached to the middle portion 110 .
[0053] The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
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A method includes flattening a first end portion and a second end portion of a first sealed end of a container. The container is filled with food product and includes a second sealed end positioned opposite the first sealed end. The method further includes folding the first end portion and the second end portion towards a middle portion of the first sealed end of the container that is located between the first and second end portions of the first sealed end of the container.
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FIELD OF THE INVENTION
[0001] The present invention relates to coating devices. More particularly, the present invention relates to an integrated cross-wire fixture for holding a stent or other device during a coating or other process.
BACKGROUND INFORMATION
[0002] Medical devices may be coated so that the surfaces of such devices have desired properties or effects. For example, it may be useful to coat medical devices to provide for the localized delivery of therapeutic agents to target locations within the body, such as to treat localized disease (e.g., heart disease) or occluded body lumens. Localized drug delivery may avoid some of the problems of systemic drug administration, which may be accompanied by unwanted effects on parts of the body which are not to be treated. Additionally, treatment of the afflicted part of the body may require a high concentration of therapeutic agent that may not be achievable by systemic administration. Localized drug delivery may be achieved, for example, by coating balloon catheters, stents and the like with the therapeutic agent to be locally delivered. The coating on medical devices may provide for controlled release, which may include long-term or sustained release, of a bioactive material.
[0003] Aside from facilitating localized drug delivery, medical devices may be coated with materials to provide beneficial surface properties. For example, medical devices are often coated with radiopaque materials to allow for fluoroscopic visualization while placed in the body. It is also useful to coat certain devices to achieve enhanced biocompatibility and to improve surface properties such as lubriciousness.
[0004] Coatings have been applied to medical devices by processes such as dipping, spraying, vapor deposition, plasma polymerization, spin-coating and electrodeposition. Although these processes have been used to produce satisfactory coatings, they have numerous, associated potential drawbacks. For example, it may be difficult to achieve coatings of uniform thicknesses, both on individual parts and on batches of parts. Further, many conventional processes require multiple coating steps or stages for the application of a second coating material, or may require drying between coating steps or after the final coating step.
[0005] The spray-coating method has been used because of its excellent features, e.g., good efficiency and control over the amount or thickness of coating. However, conventional spray-coating methods, which may be implemented with a device such as an airbrush, have drawbacks. For example, when a medical device has a structure such that a portion of the device obstructs sprayed droplets from reaching another portion of the device, then the coating becomes uneven. Specifically, when a spray-coating is employed to coat a stent having a tube-like structure with openings, such as stents described in U.S. Pat. Nos. 4,655,771 and 4,954,126 to Wallsten, the coating on the inner wall of the tube-like structure may tend to be thinner than that applied to the outer wall of the tube-like structure. Hence, conventional spraying methods may tend to produce coated stents with coatings that are not uniform. Furthermore, conventional spraying methods are inefficient. In particular, generally only 5% of the coating solution that is sprayed to coat the medical device is actually deposited on the surface of the medical device. The majority of the sprayed coating solution may therefore be wasted.
[0006] In addition to the spray coating and spin-dipping methods, the electrostatic deposition method has been suggested for coating medical devices. For example, U.S. Pat. Nos. 5,824,049 and 6,096,070 to Ragheb et al. mention the use of electrostatic deposition to coat a medical device with a bioactive material. In the conventional electrodeposition or electrostatic spraying method, a surface of the medical device is electrically grounded and a gas may be used to atomize the coating solution into droplets. The droplets are then electrically charged using, for example, corona discharge, i.e., the atomized droplets are electrically charged by passing through a corona field. Since the droplets are charged, when they are applied to the surface of the medical device, they will be attracted to the surface since it is grounded.
[0007] Conventionally, stents are coated using a nozzle to apply a solution containing a polymer and drug. The stent is held as it is moved in front of the spray nozzle by a fixture called a cross-wire that is comprised of fine wires which make contact with the stent struts.
[0008] Loading a stent on a conventional cross-wire fixture may be a complicated process, and there are various opportunities for errors in the loading process. The process steps for loading a stent on a conventional cross-wire fixture may include: loading a stent onto a cross-wire fixture; loading the cross-wire fixture with the stent into a multi-sprayer collar; and placing the assembly in a vertical alignment system and aligning it.
[0009] The existing means of mounting conventional stents for a spray coating process may include two tooling parts, namely an assembly cross-wire fixture and a production collar (also referred to as a multi-sprayer collet). This process involves a sensitive assembly and handling process. The nature of the design of the cross-wire fixture assembly means that the fixture may be strained beyond its elastic limit or the wire strained or broken during stent loading.
[0010] FIG. 1 shows conventional cross-wire fixture 100 and conventional collet 110 . Conventional cross-wire fixture 100 includes end loop C frame 101 , long C frame 102 , and collet fixture C frame 103 . Looped over end loop C frame 101 and collet fixture C frame 103 is cross-wire 140 , which includes end loop of cross-wire 141 and collet-side loop of cross-wire 142 . Specifically end loop of cross-wire 141 loops over end loop C frame 101 , while collet-side loop of cross-wire 142 loops over collet fixture C frame 103 . The central section of cross-wire 140 extends between end loop C frame 101 and collet fixture C frame 103 and is taut.
[0011] Conventional collet 110 of FIG. 1 includes frame fixture fitting 111 , pick and place interface 112 , and stem shaft 113 . During the fixturing process, after the stent is places on cross-wire 140 , conventional cross-wire fixture 100 is inserted in conventional collet 110 by moving it in the direction of arrow 120 .
[0012] FIG. 2 . 1 illustrates conventional cross-wire fixture 100 with cross-wire 140 correctly installed. FIGS. 2 . 2 to 2 . 5 depict some of the potential problems associated with conventional cross-wire fixture 100 . Some inadequacies shown relate to the relationship between conventional cross-wire fixture 100 and cross-wire 140 . FIG. 2 . 2 illustrates that, during installation, the fixture may be strained beyond its elastic limit. This results in a bent C frame, possibly causing the wire to be slack. Alternatively, the wire may be short, making it difficult to align the loaded stent, as shown in FIG. 2 . 3 . The wire may be too long, making it difficult to tension and align the loaded stent, as shown in FIG. 2 . 4 . The wire may be broken by the operator while manipulating the assembly, as shown in FIG. 2 . 5 .
[0013] Another problem arises from the requirement that the fixture be fitted to the collar each time a new stent (or other medical device) is installed on the cross-wire. The fixture to collar fit may be incorrect due to the open-ended design of the fixture. The fixture may be installed in an incorrect orientation with respect to the collar, may not be installed completely in the collar slot, and/or may be bent or otherwise damaged during the installation in the collar. Additionally, the collar slot may become fouled or otherwise blocked or damaged causing the fixture to become unusable.
[0014] A stent or other device that is fixtured on a cross-wire frame may undergo various processes while fixtured, including pre-weighing, aligning, spraying, drying (by heating, blowing and/or a vacuum), post-weighing, and final inspection.
[0015] An insert molding process allows the integration of a metal (or other material) device with a plastic, polyurethane, or other injection molded material. The metal (or similar material) device may be precisely aligned with the mold of the injection molded material to create a uniform product. This process is used to make screwdrivers, phasetesters, and similar objects.
[0016] There is, therefore, a need for a simple, cost-effective device for fixturing a medical appliance or other device that facilitates coating of the devices. Each of the references cited herein is incorporated by reference herein for background information.
SUMMARY
[0017] A fixture is provided for holding a hollow, cylindrical device from an inside surface that includes a plastic collar component and a main frame fixture insert molded into the plastic collar component. The fixture includes a cross-wire adapted to: loop over a section of the main frame fixture; traverse a space between the main frame fixture and the plastic collar component; and loop over a section of the plastic collar component.
[0018] In the fixture, the section of the plastic collar component may include two tabs. In the fixture, the plastic collar component may be adapted to visually indicate an incorrectly looped cross-wire. The plastic collar component may be adapted to accommodate a correctly looped cross-wire in a groove of the plastic collar component or parallel to a feature of the plastic collar component. The plastic collar component may be adapted to accommodate the incorrectly looped cross-wire across a groove of the plastic collar component or across a feature of the plastic collar component.
[0019] The fixture may include a trigger-activated tensioner adapted to tension the cross-wire on the main frame fixture.
[0020] In the fixture, the main frame fixture may include a symmetric design. The symmetric design may include two oval halves. The symmetric design may include two rectangular halves.
[0021] In the fixture, the plastic collar component may include a pick-and-place interface and a stem shaft. The pick-and-place interface may include a molding sink relief adapted to be manipulated by a robotic arm.
[0022] In the fixture, the fixture may be adapted to hold a stent during a coating operation.
[0023] An apparatus is provided for holding a cylindrical device having an open interior and at least one open end. The apparatus includes an engagement arrangement including at least two activatable projections on a distal end and a base attached to a proximal end of the engagement arrangement. The projections move radially when activated.
[0024] The apparatus may be adapted to hold a stent during a coating operation.
[0025] The projections may be releasable and may move axially when released. When the projections are released, the cylindrical device may slide freely over the projections. The apparatus may include a trigger coupled to the base and adapted to release the projections.
[0026] The engagement arrangement may be spring-loaded to activate the projections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 shows a conventional cross-wire fixture, a cross-wire, and a collate.
[0028] FIG. 2 . 1 shows a conventional cross-wire fixture with a cross-wire in a normal condition.
[0029] FIGS. 2 . 2 to 2 . 5 show conventional cross-wire fixtures with cross-wires in a variety of abnormal conditions.
[0030] FIG. 3 shows an integrated cross-wire fixture according to an exemplary embodiment of the present invention.
[0031] FIGS. 4 . 1 and 4 . 2 show two additional views of the integrated cross-wire fixture shown in FIG. 3 .
[0032] FIG. 5 shows an integrated cross-wire fixture according to an alternative exemplary embodiment of the present invention.
[0033] FIGS. 6 . 1 and 6 . 2 show an integrated cross-wire fixture according to another alternative exemplary embodiment of the present invention, with and without a stent.
[0034] FIG. 7 shows an integrated cross-wire fixture according to another alternative exemplary embodiment of the present invention.
[0035] FIG. 8 shows a flowchart for performing an exemplary method of the present invention.
DETAILED DESCRIPTION
[0036] The integrated cross-wire fixture is a device which combines two separate assembly components into one. In particular, the integrated cross-wire fixture combines the multi-sprayer collet/collar and the cross-wire fixture, used in the mounting of the stents during the drug coating/spraying process, into one integrated component. Both the multi-sprayer collar and the cross-wire fixture are completely re-designed to suit an insert molding manufacturing process. In combining versions of two existing tooling components, the design combines three currently complex production process steps into two simpler steps.
[0037] The new process includes: loading a stent onto the integrated cross-wire fixture; and placing the integrated cross-wire fixture into a vertical alignment system and aligning.
[0038] FIG. 3 shows integrated cross-wire fixture 300 . Integrated cross-wire fixture 300 comprises a bent stainless steel wire component (fixture main frame 320 ) insert molded into a plastic housing (insert molded collet section 310 ). The cross-wire element (cross-wire 140 ) may also be already assembled or may be fitted during stent mounting.
[0039] The insert molding manufacturing process makes the entire assembly more dimensionally consistent and repeatable. There is reduced assembly and complexity compared to the existing process. The design of cross-wire anchors 311 for the lower cross-wire allows flexibility in its design, as it is integrally molded as part of the overall housing. FIG. 4 . 1 shows how cross-wire anchors 311 are keyed to facilitate correct installation of cross-wire 140 . Backwards installation of cross-wire 140 , which is a frequent problem in the conventional process resulting in eccentric mounting of the entire stent, is thereby avoided.
[0040] FIG. 4 . 2 shows the assymetric design of central axis side of loop anchor 314 and loop crossing side of loop anchor 315 . Symmetric design of fixture main frame 320 maintains concentricity between cross-wire 140 and the central axis of integrated cross-wire fixture 300 . This feature also makes the wire fixture element (fixture main frame 320 ) self centering and reduces the chance of misalignment due to process handling, which is apparent in FIG. 4 . 2 .
[0041] The insert molding process is simplified from that of conventional production collars. The proposed collar element has no requirement for a cored inner (also referred to herein as a collar slot) to accommodate installation of a cross-wire fixture, because fixture main frame 320 is insert molded as part of the manufacture. The design of integrated cross-wire fixture 300 allows for more flexibility in the overall shape of the insert molded collet section 310 allowing for integration of such features as 2D matrix coding, radio frequency identification (RFID) tagging, laser etching, and other identification and process control devices and systems. The design of insert molded collet section 310 accommodates the existing process stent coating process while conforming to a design which is suitable for injection molding.
[0042] FIG. 4 . 2 shows integrated cross-wire fixture 300 in a side view. The stent mounting element (fixture main frame 320 ) is mounted eccentrically so that cross-wire 140 , and therefore the stent, locates coaxially onto the overall collar.
[0043] There are several alternative designs that utilize some or all of the features of the integrated cross-wire fixture. Alternative shapes of bent wire fixture (in side profile), such as curved wires rather than a square frame are also possible. FIG. 5 shows curved main frame fixture 510 in curved integrated cross-wire fixture 500 . Additionally, alternative shapes for a main frame fixture, including assymetric shapes, may also be possible.
[0044] One-piece, all plastic injection molded production collars and stent mounting fixtures are also possible. One such design is shown in FIGS. 6 . 1 and 6 . 2 . Diamond assembly integrated fixture 600 is shown holding stent 620 in FIG. 6 . 1 . Diamond frame 610 may be retracted radially inward either manually or with a trigger or button. In a retracted state, stent 620 may be inserted over diamond frame 610 . Subsequently, either by releasing diamond frame 610 , applying an opening force manually to diamond frame 610 , or by releasing the trigger or button, diamond frame 610 may be returned to its extended position, as shown in FIGS. 6 . 1 and 6 . 2 . As shown in FIG. 6 . 1 , diamond frame 610 in the extended position may hold stent 620 from the inside.
[0045] FIG. 7 shows another alternative design. Integrated tuning fork fixture 700 includes bent tuning fork-type wire arrangement 710 that is insert molded into a plastic production collar element. FIG. 7 shows bent tuning fork-type wire arrangement 710 holding stent 620 with an outward force on bent tuning fork-type wire arrangement 710 . The two tines of bent tuning fork-type wire arrangement 710 may be closed into an axial position either manually or by a trigger or button in order to install or remove a stent from integrated tuning fork fixture 700
[0046] There are several alternative materials and/or coatings that may be utilized in the integrated cross-wire fixture. Stainless steel wire of various material content depending on the mechanical characteristics required. Fixture may be made from Nitinol wire with shape memory characteristics for stent mounting purposes. Plastics may be selected for use based on flexibility, stiffness, and/or shape memory characteristics.
[0047] There are several alternative applications utilizing the integrated cross-wire fixture. The integrated cross-wire fixture may be used in spray coating, of bioactive agents or surface coatings, or any other processing step requiring access to the external surface of a stent or other medical device or implant.
[0048] FIG. 8 shows a flowchart for performing an exemplary method of the present invention. The flow in FIG. 8 starts in start circle 80 and flows to action 81 , which indicates to provide a plastic collar component and a main frame fixture insert molded into the plastic collar component. From action 81 , the flow proceeds to action 82 , which indicates to loop a cross-wire over a section of the main frame fixture. From action 82 , the flow proceeds to action 83 , which indicates to insert the cross-wire through a hollow section of the a device. From action 83 , the flow proceeds to action 84 , which indicates to loop the cross-wire over a section of the plastic collar component. From action 84 , the flow proceeds to action 85 , which indicates to align the device. From action 85 , the flow proceeds to end circle 86 .
[0049] As used herein, the term “therapeutic agent” includes one or more “therapeutic agents” or “drugs”. The terms “therapeutic agents”, “active substance” and “drugs” are used interchangeably herein and include pharmaceutically active compounds, nucleic acids with and without carrier vectors such as lipids, compacting agents (such as histones), virus (such as adenovirus, andenoassociated virus, retrovirus, lentivirus and α-virus), polymers, hyaluronic acid, proteins, cells and the like, with or without targeting sequences.
[0050] The therapeutic agent may be any pharmaceutically acceptable agent such as a non-genetic therapeutic agent, a biomolecule, a small molecule, or cells.
[0051] Exemplary non-genetic therapeutic agents include anti-thrombogenic agents such heparin, heparin derivatives, prostaglandin (including micellar prostaglandin E1), urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone); anti-proliferative agents such as enoxaprin, angiopeptin, sirolimus (rapamycin), tacrolimus, everolimus, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid; anti-inflammatory agents such as dexamethasone, rosiglitazone, prednisolone, corticosterone, budesonide, estrogen, estrodiol, sulfasalazine, acetylsalicylic acid, mycophenolic acid, and mesalamine; anti-neoplastic/anti-proliferative/anti-mitotic agents such as paclitaxel, epothilone, cladribine, 5-fluorouracil, methotrexate, doxorubicin, daunorubicin, cyclosporine, cisplatin, vinblastine, vincristine, epothilones, endostatin, trapidil, halofuginone, and angiostatin; anti-cancer agents such as antisense inhibitors of c-myc oncogene; anti-microbial agents such as triclosan, cephalosporins, aminoglycosides, nitrofurantoin, silver ions, compounds, or salts; biofilm synthesis inhibitors such as non-steroidal anti-inflammatory agents and chelating agents such as ethylenediaminetetraacetic acid, O,O′-bis (2-aminoethyl)ethyleneglycol-N,N,N′,N′-tetraacetic acid and mixtures thereof; antibiotics such as gentamycin, rifampin, minocyclin, and ciprofolxacin; antibodies including chimeric antibodies and antibody fragments; anesthetic agents such as lidocaine, bupivacaine, and ropivacaine; nitric oxide; nitric oxide (NO) donors such as lisidomine, molsidomine, L-arginine, NO-carbohydrate adducts, polymeric or oligomeric NO adducts; anti-coagulants such as D-Phe-Pro-Arg chloromethyl ketone, an RGD peptide-containing compound, heparin, antithrombin compounds, platelet receptor antagonists, anti-thrombin antibodies, anti-platelet receptor antibodies, enoxaparin, hirudin, warfarin sodium, Dicumarol, aspirin, prostaglandin inhibitors, platelet aggregation inhibitors such as cilostazol and tick antiplatelet factors; vascular cell growth promotors such as growth factors, transcriptional activators, and translational promotors; vascular cell growth inhibitors such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin; cholesterol-lowering agents; vasodilating agents; agents which interfere with endogeneus vascoactive mechanisms; inhibitors of heat shock proteins such as geldanamycin; and any combinations and prodrugs of the above.
[0052] Exemplary biomolecules include peptides, polypeptides and proteins; oligonucleotides; nucleic acids such as double or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), and ribozymes; genes; carbohydrates; angiogenic factors including growth factors; cell cycle inhibitors; and anti-restenosis agents. Nucleic acids may be incorporated into delivery systems such as, for example, vectors (including viral vectors), plasmids or liposomes.
[0053] Non-limiting examples of proteins include monocyte chemoattractant proteins (“MCP-1) and bone morphogenic proteins (“BMP's”), such as, for example, BMP-2, BMP-3, BMP-4, BMP-5, BMP-6 (Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13, BMP-14, BMP-15. Preferred BMPS are any of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, and BMP-7. These BMPs can be provided as homdimers, heterodimers, or combinations thereof, alone or together with other molecules. Alternatively, or in addition, molecules capable of inducing an upstream or downstream effect of a BMP can be provided. Such molecules include any of the “hedghog” proteins, or the DNA's encoding them. Non-limiting examples of genes include survival genes that protect against cell death, such as anti-apoptotic Bcl-2 family factors and Akt kinase and combinations thereof. Non-limiting examples of angiogenic factors include acidic and basic fibroblast growth factors, vascular endothelial growth factor, epidermal growth factor, transforming growth factor α and β, platelet-derived endothelial growth factor, platelet-derived growth factor, tumor necrosis factor α, hepatocyte growth factor, and insulin like growth factor. A non-limiting example of a cell cycle inhibitor is a cathespin D (CD) inhibitor. Non-limiting examples of anti-restenosis agents include p15, p16, p18, p19, p21, p27, p53, p57, Rb, nFkB and E2F decoys, thymidine kinase (“TK”) and combinations thereof and other agents useful for interfering with cell proliferation.
[0054] Exemplary small molecules include hormones, nucleotides, amino acids, sugars, and lipids and compounds have a molecular weight of less than 100 kD.
[0055] Exemplary cells include stem cells, progenitor cells, endothelial cells, adult cardiomyocytes, and smooth muscle cells. Cells can be of human origin (autologous or allogenic) or from an animal source (xenogenic), or genetically engineered.
[0056] Any of the therapeutic agents may be combined to the extent such combination is biologically compatible.
[0057] Any of the above mentioned therapeutic agents may be incorporated into a polymeric coating on the medical device or applied onto a polymeric coating on a medical device. The polymers of the polymeric coatings may be biodegradable or non-biodegradable. Non-limiting examples of suitable non-biodegradable polymers include polyvinylpyrrolidone including cross-linked polyvinylpyrrolidone; polyvinyl alcohols, copolymers of vinyl monomers such as EVA; polyvinyl ethers; polyvinyl aromatics; polyethylene oxides; polyesters including polyethylene terephthalate; polyamides; polyacrylamides; polyethers including polyether sulfone; polyalkylenes including polypropylene, polyethylene and high molecular weight polyethylene; polyurethanes; polycarbonates, silicones; siloxane polymers; cellulosic polymers such as cellulose acetate; polymer dispersions such as polyurethane dispersions (BAYHDROL®); squalene emulsions; and mixtures and copolymers of any of the foregoing.
[0058] Non-limiting examples of suitable biodegradable polymers include polycarboxylic acid, polyanhydrides including maleic anhydride polymers; styrene-isobutylene-styrene block copolymers such as styrene-isobutylene-styrene tert-block copolymers (SIBS); polyorthoesters; poly-amino acids; polyethylene oxide; polyphosphazenes; polylactic acid, polyglycolic acid and copolymers and mixtures thereof such as poly(L-lactic acid) (PLLA), poly(D,L,-lactide), poly(lactic acid-co-glycolic acid), 50/50 (DL-lactide-co-glycolide); polydioxanone; polypropylene fumarate; polydepsipeptides; polycaprolactone and co-polymers and mixtures thereof such as poly(D,L-lactide-co-caprolactone) and polycaprolactone co-butylacrylate; polyhydroxybutyrate valerate and blends; polycarbonates such as tyrosine-derived polycarbonates and arylates, polyiminocarbonates, and polydimethyltrimethylcarbonates; cyanoacrylate; calcium phosphates; polyglycosaminoglycans; macromolecules such as polysaccharides (including hyaluronic acid; cellulose, and hydroxypropylmethyl cellulose; gelatin; starches; dextrans; alginates and derivatives thereof), proteins and polypeptides; and mixtures and copolymers of any of the foregoing. The biodegradable polymer may also be a surface erodable polymer such as polyhydroxybutyrate and its copolymers, polycaprolactone, polyanhydrides (both crystalline and amorphous), maleic anhydride copolymers, and zinc-calcium phosphate.
[0059] In a preferred embodiment, the polymer is polyacrylic acid available as HYDROPLUS® (Boston Scientific Corporation, Natick, Mass.), and described in U.S. Pat. No. 5,091,205, the disclosure of which is incorporated by reference herein. In a more preferred embodiment, the polymer is a co-polymer of polylactic acid and polycaprolactone.
[0060] Such coatings used with the present invention may be formed by any method known to one in the art. For example, an initial polymer/solvent mixture can be formed and then the therapeutic agent added to the polymer/solvent mixture. Alternatively, the polymer, solvent, and therapeutic agent can be added simultaneously to form the mixture. The polymer/solvent mixture may be a dispersion, suspension or a solution. The therapeutic agent may also be mixed with the polymer in the absence of a solvent. The therapeutic agent may be dissolved in the polymer/solvent mixture or in the polymer to be in a true solution with the mixture or polymer, dispersed into fine or micronized particles in the mixture or polymer, suspended in the mixture or polymer based on its solubility profile, or combined with micelle-forming compounds such as surfactants or adsorbed onto small carrier particles to create a suspension in the mixture or polymer. The coating may comprise multiple polymers and/or multiple therapeutic agents.
[0061] The coating can be applied to the medical device by any known method in the art including dipping, spraying, rolling, brushing, electrostatic plating or spinning, vapor deposition, air spraying including atomized spray coating, and spray coating using an ultrasonic nozzle.
[0062] The coating is typically from about 1 to about 50 microns thick. In the case of balloon catheters, the thickness is preferably from about 1 to about 10 microns, and more preferably from about 2 to about 5 microns. Very thin polymer coatings, such as about 0.2-0.3 microns and much thicker coatings, such as more than 10 microns, are also possible. It is also within the scope of the present invention to apply multiple layers of polymer coatings onto the medical device. Such multiple layers may contain the same or different therapeutic agents and/or the same or different polymers. Methods of choosing the type, thickness and other properties of the polymer and/or therapeutic agent to create different release kinetics are well known to one in the art.
[0063] The medical device may also contain a radio-opacifying agent within its structure to facilitate viewing the medical device during insertion and at any point while the device is implanted. Non-limiting examples of radio-opacifying agents are bismuth subcarbonate, bismuth oxychloride, bismuth trioxide, barium sulfate, tungsten, and mixtures thereof.
[0064] Non-limiting examples of medical devices according to the present invention include catheters, guide wires, balloons, filters (e.g., vena cava filters), stents, stent grafts, vascular grafts, intraluminal paving systems, implants and other devices used in connection with drug-loaded polymer coatings. Such medical devices may be implanted or otherwise utilized in body lumina and organs such as the coronary vasculature, esophagus, trachea, colon, biliary tract, urinary tract, prostate, brain, lung, liver, heart, skeletal muscle, kidney, bladder, intestines, stomach, pancreas, ovary, cartilage, eye, bone, and the like.
[0065] While the present invention has been described in connection with the foregoing representative embodiment, it should be readily apparent to those of ordinary skill in the art that the representative embodiment is exemplary in nature and is not to be construed as limiting the scope of protection for the invention as set forth in the appended claims.
[0000] Drawings Legend
[0000]
100 —conventional cross-wire fixture
101 —end loop C frame
102 —long C frame
103 —collet fixture C frame
110 —conventional collet
111 —frame fixture fitting
112 —pick and place interface
113 —stem shaft
120 —direction of insertion of cross-wire into collet
140 —cross-wire
141 —end loop of cross-wire
142 —collet-side loop of cross-wire
300 —integrated cross-wire fixture
310 —insert molded collet section
311 —cross-wire anchors
312 —molded collet-fixture interface
313 —molding sink relief
314 —central axis side of loop anchor
315 —loop crossing side of loop anchor
320 —fixture main frame
500 —curved integrated cross-wire fixture
510 —curved main frame fixture
600 —diamond assembly integrated fixture
610 —diamond frame
620 —stent
700 —integrated tuning fork fixture
710 —bent tuning fork-type wire arrangement
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A fixture is provided for holding a hollow, cylindrical device from an inside surface that includes a plastic collar component and a main frame fixture insert molded into the plastic collar component. The fixture may include a cross-wire adapted to: loop over a section of the main frame fixture; traverse a space between the main frame fixture and the plastic collar component; and loop over a section of the plastic collar component. An apparatus is provided for holding a cylindrical device having an open interior and at least one open end. The apparatus includes an engagement arrangement including at least two activatable projections on a distal end and a base attached to a proximal end of the engagement arrangement. The projections move radially when activated.
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REFERENCE TO RELATED APPLICATIONS
The present invention is related to co-pending application Ser. No. 06/881,339 filed July 2, 1986, in the name of the same inventor and entitled SELF-CONTAINED INTERNAL COMBUSTION FASTENER DRIVING TOOL; and to co-pending application Ser. No. 06/881,343, filed July 2, 1986 in the name of the same inventor and entitled CAM-CONTROLLED SELF-CONTAINED INTERNAL COMBUSTION FASTENER DRIVING TOOL.
TECHNICAL FIELD
The invention relates to an internal combustion fastener driving tool, and more particularly to such a tool having a positive-control cam system with simple two-way valves to actuate the full cycle of the tool by actuation of a trigger, and being self contained, having replaceable canisters of gaseous fuel and oxidizer mounted therein.
BACKGROUND ART
The majority of fastener driving tools in use today are pneumatically actuated tools. Pneumatic fastener driving tools have been developed to a high degree of sophistication and efficiency, but require a source of air under pressure and are literally tied thereto by hose means. Under some circumstances, particularly in the field, a source of air under pressure is not normally present and is expensive and sometimes difficult to provide.
Prior art workers have also developed a number of electro-mechanical fastener driving tools, usually incorporating one or more flywheels with one or more electric motors therefor. Such tools require a source of electrical current which is normally present at the job site. However, this type of tool is also quite literally "tied" to a power source.
Under certain circumstances, it is desirable to utilize a completely self-contained fastener driving tool, not requiring attachment to a source of air under pressure or a source of electrical current. To this end, prior art workers have devised self-contained fastener driving tools powered by internal combustion of a gaseous fuel-air mixture. It is to this type of tool that the present invention is directed.
Exemplary prior art internal combustion fastener driving tools are taught, for example, in U.S. Pat. Nos. 2,898,893; 3,042,008; 3,213,607; 3,850,359; 4,075,850; 4,200,213; 4,218,888; 4,403,722; 4,415,110; and European Patent Applications Nos. 0 056 989; and 0 056 990. While such tools function well, they are usually large, complex, heavy and awkward to use.
The fastener driving tool of the present invention comprises a self-contained internal combustion tool which is compact, easy to manipulate and unusually simple in construction. The fastener driving tool is highly efficient, operating on a moderate compression ratio to convert most of the fuel energy into useful work. The tool carries a replaceable canister of gaseous fuel and a replaceable canister of oxidizer. This eliminates the necessity for a combustion air chamber and its attendant passages and valving, as well as a second cylinder and piston acting as a compressor during the tool cycle to replenish air under pressure in a combustion air chamber. As a result, the tool has a single cylinder, provided with a piston/driver which, during a tool cycle, drives a fastener into a workpiece and fills a return air chamber (to which the cylinder is connected) with air under pressure.
The fastener driving tool is provided with a positive, trigger-actuated cam system which sequences the tool through its cycle, upon actuation of the trigger. The cam system operates a series of two-way valves and an ignition device.
DISCLOSURE OF THE INVENTION
According to the invention there is provided a fastener driving tool which is self-contained and uses internal combustion of a gaseous oxidizer-fuel as its driving force. The tool comprises a tool housing or body, including a handle portion. A guide body is mounted at the lower end of the housing. A magazine, containing a plurality of fasteners, is supported at one end by the guide body and at its other end by the handle portion.
The tool body contains a single cylinder. The cylinder is surrounded and connected to a return air chamber, and contains a piston/driver assembly for driving a fastener during the tool cycle. The upper end of the cylinder is provided with a closure defining a combustion chamber having an ignition means. The piston of the piston/driver assembly, when in its normal unactuated position, constitutes the bottom of the combustion chamber.
The tool cycle is controlled by a positive, trigger-actuated cam system. Upon actuation of the trigger, the cam system is configured to first open a fuel valve to introduce a measured amount of gaseous fuel from the canister thereof into the combustion chamber. Thereafter, the cam system opens an oxidizer valve to introduce a measured quantity of oxidizer from the canister thereof into the combustion chamber. The cam system next actuates the ignition device to combust the oxidizer/fuel mixture. This combustion causes the piston/driver assembly to drive a fastener and to fill the return air chamber with air under pressure. Finally, the cam system is configured to actuate a control or pilot valve which admits some of the air under pressure from the return air chamber to an exhaust valve, opening the exhaust valve to eliminate the spent products of combustion from the combustion chamber. This, in turn, enables the piston/driver assembly to be shifted to its normal position by air under pressure from the return air chamber. Thereafter, the tool is ready for its next actuation and driving cycle. As will be pointed out hereinafter, the same sequence control can be achieved through the use of a single trigger-actuated cam, rather than a system of cams.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the self-contained internal combustion fastener driving tool of the present invention.
FIG. 2 is a front elevational view of the tool of FIG. 1, partly in cross section to reveal the spark plug, the exhaust valve and the combustion chamber.
FIG. 3 is a plan view of the tool of FIG. 1.
FIG. 4 is a cross-sectional elevational view of the tool of FIG. 1.
FIG. 5 is a fragmentary plan view of an exemplary strip of fasteners in the form of studs.
FIG. 6 is a fragmentary elevational view of the strip of fasteners of FIG. 5.
FIG. 7 is a simplified rear elevational view of the tool magazine.
FIG. 8 is a simplified rear elevation of the handle of the tool with the door removed.
FIG. 9 is a fragmentary, cross-sectional, plan view taken along section line 9--9 of FIG. 1.
FIG. 10 is a fragmentary, cross-sectional view taken along section line 10--10 of FIG. 1, with the link also shown in cross section.
FIG. 11 is a cross-sectional view taken along section line 11--11 of FIG. 1.
FIG. 12 is a diagrammatic representation of the cam system operating positions.
FIG. 13 is a diagrammatic representation of the combustion chamber, the check valve and the fuel and oxidizer valves in a second embodiment of the tool.
DETAILED DESCRIPTION OF THE INVENTION
In all of the Figures, like parts have been given like index numerals. Reference is first made to FIGS. 1-4. In these figures, the tool of the present invention is generally indicated at 1. The tool 1 comprises a main housing 2 having a handle 3. A guide body 4 is affixed to the lower end of the main housing. A magazine for fasteners is illustrated at 5, being affixed at its forward end to the guide body 4 and at its rearward end to the handle 3.
Turning to FIG. 4, the housing 2 comprises a cylindrical member 6. The lower end of cylindrical member 6 is closed by a bottom cap 7, removably affixed thereto by any suitable means such as bolts or the like (not shown). The cylindrical housing member 6 contains a cylinder 8. The cylinder 8 carries on its exterior surface O-rings 9 and 10 forming a fluid tight seal with the inside surface of cylindrical housing member 6. The inside surface of the cylindrical housing member 6 and the exterior surface of cylinder 8 are so configured as to form an annular return air chamber 11 therebetween, the purpose of which will be apparent hereinafter. The bottom cap 7 also closes the bottom end of cylinder 8.
The cylinder 8 is provided with two annular rows of perforations 12 and 13 communicating with the return air chamber. Each of the annular rows of perforations 12 and 13 may, when required be surrounded by an O-ring (as at 14 and 15) serving as one-wa valves from cylinder 8 to return air chamber 11.
The cylinder 8 contains a piston/driver assembly, generally indicated at 16, and comprising a piston portion 16a and an elongated driver portion 16b. The bottom cap 7 has a bore 17, having a first portion 17a of a diameter to just nicely receive the driver portion 16b of piston/driver assembly 16, and a portion 17b of larger diameter. The larger diameter portion 17b of bore 17 receives the end of guide body 4 together with O-ring 18. The O-ring 18 makes a fluid tight seal between guide body 4 and lower cap 7, as well as between the guide body 4, the lower cap 7 and the driver portion 16b of piston/driver assembly 16. Bottom cap 7 is provided with at least one bore 19 and guide body 4 is provided with at least one matching, coaxial bore 20, which bores are normally closed by a flapper valve 21. The purpose of bores 19 and 20 and flapper valve 21 will be apparent hereinafter. It would be within the scope of the present invention to make the bottom cap 7 and the guide body 4 as a single part.
A resilient bumper 22, adapted to absorb the energy of the piston/driver assembly 16 at the bottom of its stroke is located at the bottom of cylinder 8. It will be noted that the piston portion 16a of piston/driver assembly 16 supports an O-ring 23, making a fluid tight seal with the inside surface of cylinder 8. In FIG. 4, the piston/driver assembly 16 is shown in its uppermost position, abutting a cap 24 which closes the upper end of cylinder 8 and the upper end of body member 6. The cap 24 carries an O-ring 25 which sealingly engages in fluid tight fashion the inside surface of body member 6.
The bottom surface of cap 24 has a dome-like depression 26 formed therein, the domed depression 26, together with the piston portion 16a of piston/driver assembly 16 (in its uppermost position) defining a combustion chamber 27.
Referring particularly to FIGS. 2, 3 and 4, the upper surface of cap 24 has a depression 28 formed therein. The bottom of depression 28 communicates with combustion chamber 27 through a bore 29. An ignition device 30, in the form of a spark plug, is threadedly engaged in bore 29 and extends into combustion chamber 27. The cap 24 has a second vertical bore 31 formed therein, in which is mounted a two-way, normally closed, pilot actuated exhaust valve 32. As can most clearly be seen in FIG. 2, the inlet of exhaust valve 32 communicates with combustion chamber 27. The outlet of exhaust valve 32 communicates with a transverse bore 33 formed in cap 24 and leading to cap depression 28. In this way, exhaust valve 32 can exhaust combustion chamber 27 to atmosphere as will be described hereinafter. An exhaust shield 34 (FIG. 2) can be affixed to the upper surface of cap 24 by any appropriate means.
The guide body 4 has a longitudinal slot or bore 35 constituting a drive track for the driver portion 16b of the piston/driver assembly 16. As indicated above, the tool of the present invention may be used to drive any appropriate type of fastening means including studs, nails, staples and the like. For purposes of an exemplary showing, the tool is illustrated in an embodiment suitable for driving studs. It will be understood that the configuration of the driver portion 16b of piston/driver assembly 16, the configuration of drive track 35 and the nature of magazine 5 can vary, depending upon the type of fastener to be driven by the tool 1.
Reference is now made to FIGS. 5 and 6. The exemplary fasteners are illustrated in FIGS. 5 and 6 as headed studs 36. The studs are supported by an elongated plastic strip generally indicated at 37. As can best be ascertained from FIG. 5, the plastic strip 37 is an integral, one-piece structure comprising two elongated ribbon-like members 37a and 37b joined together by a plurality of circular washer-like members 37c. The washer-like members 37c have central perforations sized to snugly receive the shanks of studs 36. When each stud is driven, in its turn, by the driver portion 16b of piston/driver assembly 16, its respective washer-like structure 37c will break away from ribbon-like members 37a and 37b and will remain with the stud.
Reference is now made to FIGS. 4 and 7. The magazine 5 has a central opening 38 extending longitudinally thereof and accommodating the studs 36. The opening 38 is flanked on each side by shallow transverse slots 39 and 40, also extending longitudinally of magazine 5. The ribbon-like portions 37a and 37b of the strip 37 are slidably received in the slots 39 and 40, respectively. The rearward wall of the guide body 4 has a slot 41 formed therein corresponding to the opening 38 of magazine 5. The guide body slot 41 is intersected by a pair of transverse slots, one of which is shown at 42. These slots correspond to magazine slots 39 and 40, and similarly cooperate with the ribbon-like portions 37a and 37b of strip 37. The forward wall of guide body 4 has a pair of transverse slots 43 and 44 formed therein (see also FIG. 2). The slots 43 and 44 are larger in size than ribbon-like strip portions 37a and 37b and permit scrap portions of strip elements 37a and 37b, from which the studs 36 and washer-like elements 37c have been removed, to exit the tool 1.
From the above description it will be apparent that the studs 36 are supported by strip 37, and that the strip 37, itself, is slidably supported within magazine 5. With the studs depending downwardly in opening 38 and strip portions 37a and 37b slidably engaged in magazine slots 39 and 40, the guide body rear wall slots (one of which is shown at 42) and the guide body front wall slots 43 and 44. The forwardmost stud 36 of the strip enters the drive track 35 of guide body 4 via slot 41 and is properly located under the driver portion 16b of piston/driver assembly 16 by its respective washer 37c. Once the stud and washer assembly has been driven by the driver portion 16b of piston/driver assembly 16, the strip 37 will advance in the magazine 5 and guide body 4 to locate the next forwardmost stud 36 in guide body drive track 35, as soon as the piston/driver assembly 16 has returned to its normal position shown in FIG. 4.
Any appropriate means can be employed to advance the strip 37 through magazine 5 and to constantly urge the forwardmost stud 36 of the strip 37 into the guide body drive track 35. For purposes of an exemplary showing, a feeder shoe 45 is illustrated in FIGS. 4 and 7. The feeder shoe 45 is slidably mounted in transverse slots 46 and 47 in the magazine (see FIG. 7). The feeder shoe 45 is operatively attached to a ribbon-like spring 48 located in an appropriate socket 49 at the forward end of magazine 5. In this way, the feeder shoe 45 is constantly urged forwardly in the magazine 5, and as a result, constantly urges the stud-supporting strip 37 forwardly. The feeder shoe 45 has a handle portion 45a by which it may be easily manually retracted during the magazine loading operation. The feeder shoe 45 also pivotally mounts a lug 50. A spring (not shown) is mounted about pivot pin 51 with one leg of the spring abutting feeder shoe 45, and the other leg abutting the lug 50 to maintain the lug 50 in its downward position as shown in FIG. 4. In its downward position, the lug 50 abuts the rearward end of strip 37, enabling the feeder shoe (under the influence of spring 48) to urge the strip 37 forwardly. The lug 50 has an integral, upstanding handle 50a by which it can be pivoted upwardly toward the feeder shoe 45, and out of the way during loading of the magazine 5. The handle 3 of tool 1 is hollow. At its rearward end, the handle 3 is provided with a closure or door 52. The door 52 is hinged as at 53. The upper end of the door is provided with a notched tine 54 which cooperates with a small lug 55 on the upper surface of the handle 3, to maintain the door 52 in closed position.
The lower part of the grip portion of handle 3 is open, as at 56. This opening provides room for a manual trigger 57 which is pivotally mounted within handle 3, by pivot pin 58. The trigger 57 normally rests in its downward or most extended position, as shown in FIG. 4, by virtue of a biasing spring 59.
The upper part of the forward end of handle 3 has an extension 60. The forward end of the handle 3 is affixed to housing 2 by a series of bolts, two of which are shown at 61 in FIG. 3. The handle extension portion 60 contains a pair of bores 62 and 63. The bore 62 houses a two-way, normally closed pilot valve 64. The bore 63 houses a conventional piezoelectric device 65.
Referring to FIGS. 3 and 4, bore 62 housing two-way pilot valve 64 is connected to the return air chamber 11 by a conduit 66 and a passage 67 in housing 2. This is most clearly shown in FIG. 4. The outlet, of pilot valve 64 is connected by passages 68 and 69 in housing 2, conduit 70 and passage 71 in bottom cap 7 to cylinder 8 beneath piston/driver assembly 16 and by way of normally closed reed valve 21. The pilot valve outlet is also connected by passages 68, 72 and 73 in housing 2 to passage 74 in cap 24 leading to the actuator of exhaust valve 32. Two-way pilot valve 64 is provided with a plunger-like actuator 75, which will be further described hereinafter.
The piezoelectric device 65 has a similar actuator 76 (see FIG. 11), about which more will be stated hereafter. The piezoelectric device 65 is connected by wire means 77 to the spark plug 30 (see FIG. 3).
Reference is now made to FIGS. 1, 4 and 8. The door 52 at the rearward end of handle 3 enables the placement within the handle of a canister 78 containing a gaseous oxidizer such as oxygen or nitrogen oxide and a canister 79 containing a gaseous fuel such as propane or the like. The canister 78 is adapted to mate with a pressure regulating needle valve 80 located within handle 3 (see FIGS. 4 and 8). This mating of canister 78 with needle valve 80 opens a spring loaded valve 81, constituting a part of canister 78. Needle valve 80 has an adjustment screw 82, accessible through a perforation 83 in handle 3 (see FIG. 1). The pressure regulating needle valve 80 is connected by a conduit 84 to a normally closed, two-way oxidizer valve 85, mounted within handle 3. The outlet of valve 85 is connected by conduit 86 (fragmentarily shown in FIG. 4) to the passage 87 (see FIGS. 3 and 4) containing one-way check valve 88, and leading to combustion chamber 27. The two-way gaseous oxidizer valve 85 is provided with a plunger-like actuator 89, similar to the actuators 75 and 76 of pilot valve 64 and piezoelectric device 65.
Fuel canister 79 mates with a pressure regulating needle valve 90 located within handle 3 (see FIG. 8). This mating of canister 79 with needle valve 90 opens a spring loaded valve 91 constituting part of canister 79. Needle valve 90 has an adjustment screw (not shown) similar to adjustment screw 82 of needle valve 80 and accessible through a perforation (not shown) in handle 3 similar to perforation 83 but on the opposite side of handle 3.
Referring to FIG. 9, a normally closed, two-way fuel valve 92 is located within handle 3, alongside gaseous oxidizer valve 85. The inlet of fuel valve 92 is connected by conduit 93 to needle valve 90. The outlet of fuel valve 92 is connected by conduit 94 to passage 95 in cap 24 leading to combustion chamber 27 and having a one-way check valve 96 therein. Fuel valve 92 is provided with a plunger-like actuator 92a.
To complete the structure of tool 1, a trigger actuated control cam system is provided and is generally indicated at 97 in FIGS. 4, 9 and 10.
As is best seen in FIG. 10, the cam system 97 is made up of two parts 97a and 97b. The part 97a comprises a shaft portion 98 rotatively mounted in a perforation 99 in handle 3. The shaft portion 98 is followed by a spacer portion 100 and two cam elements 101 and 102. The elements 101 and 102 are followed by another spacer member 103 having an offset pin portion 104. The cam system portion 97b, in similar fashion has a shaft portion 105 rotatively mounted in a perforation 106 in handle 3. The pin portion 105 is followed by a spacer portion 107, a pair of cam elements 108 and 109 and a second spacer portion 110 having a pin portion 111.
When the cam system 97 is assembled, its pin portions 104 and 111 are located in a perforation 112 in a link 113. Pin portions 104 and 111 abut each other and engage each other such that they will not rotate relative to each other. When assembled, shaft portions 98 and 105 of cam system 97 are coaxial. Similarly, pin portions 104 and 111 are coaxial. The axes of these two shaft and pin sets 98-105 and 104-111 are parallel and spaced from each other. It will be understood that the cam system 97 could be made as a single, integral, one-piece part. Under such circumstances, the link 113 would be made in more than one part to enable its attachment to cam system 97.
The top end of link 113 being pivotally attached to cam system 97, the bottom end of link 113 is similarly pivotally attached to trigger 57. To this end, a pivot pin 114 passes through perforations 115 and 116 in trigger 86 and a perforation 117 at the bottom end of link 113. It will be immediately apparent from FIGS. 4, 9 and 10 that if trigger 57 is depressed against the action of trigger biasing spring 59, and then is released, the trigger link 113 will cause one complete revolution of cam system 97.
As will be apparent from FIG. 9, the plunger-like actuator 89 of gaseous oxidizer valve 85 contacts and is operated by cam element 102. Similarly, plunger-like actuator 92a of gaseous fuel valve 92 contacts and is operated by cam element 109. As is shown in FIG. 4, plunger-like actuator 75 of pilot valve 65 contacts and is operated by cam element 101. In a similar fashion, as can be ascertained from a comparison of FIGS. 10 and 11, the plunger-like actuator 76 of piezoelectric device 65 contacts and is operated by cam element 108. It will be understood that cam elements 101, 102, 108 and 109 are so configured as to operate their respective plunger-like actuators 75, 89, 76 and 92a in the proper sequence. It will further be apparent that trigger 57 be fully depressed and fully released to cause the tool 1 to operate through one complete cycle.
TOOL OPERATION
The tool 1 of the present invention having been described in detail, its operation can now be set forth as follows. Reference is made to FIG. 4, wherein the tool and its various elements are shown in their normal, unactuated conditions.
For its initial use, or if the tool has not been used for some time, air pressure in the return air chamber 11 will be at atmospheric level. Under these circumstances, before a fastener strip is loaded into the magazine, the needle valves 80 and 90 are set to an intermediate position. The tool is then ready to be primed. This can be done by actuating the tool through the trigger 57 several times, whereby the return air chamber is primed with compressed air at the operating level.
Once the tool is primed and in operating condition, the feeder shoe 45 is grasped by its handle portion 45a and pulled rearwardly with respect to magazine 5. The lug 50 is shifted out of the way by means of its handle portion 50a and a strip 37 carrying a plurality of studs 36 is loaded into the magazine 5 with the forwardmost stud being located in the drive track 35 of guide body 4. The lug 50 and feeder shoe 45 are then released.
It will be understood that a gaseous oxidizer canister 78 and a gaseous fuel canister 79 have been located in the handle and are appropriately connected to needle valves 80 and 90 respectively. The needle valves are properly adjusted by means of their adjustment screws, if required.
When it is desired to actuate tool 1, the guide body 4 is located against the workpiece at a position where it is desired to drive a stud, and the manual trigger 57 is actuated by the operator. As a result of the trigger actuation, a tool cycle is initiated, including the following sequential events.
Actuating manual trigger 57 results, through the action of the link 113 in rotation of the cam system 97. Cam elements 101, 102, 108 and 109 are so configured that cam element 109 first operates the actuator 92a of two-way fuel valve 92 introducing a metered amount of gaseous fuel into combustion chamber 27 through check valve 96. The amount of fuel introduced depends upon the setting of needle valve 90. The piston/driver assembly 16 shifts slightly downwardly due to the pressure of the gaseous fuel within combustion chamber 27. When the cooperation of cam element 109 and actuator 92a begins to close fuel valve 92, the next operation of the cycle is initiated.
Continued rotation of the cam system 97 initiates the second operation of the cycle wherein cam element 102 operates actuator 89 of oxidizer valve 85, introducing a metered amount of oxidizer from canister 78 into the combustion chamber 27 through one-way valve 88. As a result of this operation, the proper mixture of oxidizer and fuel is present in combustion chamber 27. The oxidizer/fuel mixture is under moderate compression ratio (for example 2:1 and preferably about 1:3 or more) assuring the most complete burning and the most efficient use of the fuel. The piston/driver assembly 16, at this point, is pressed against the head of the forwardmost stud 36 located in guide body drive track 35. The strip 37, supporting studs 36, is designed to be strong enough to withstand the loading due to the pressure of the oxidizer/fuel mixture over the piston/driver assembly 16. As the cam system 97 continues to rotate and the interaction of cam element 102 and actuator 89 begins to close oxidizer valve 85, the next operation is initiated.
The third operation of the cycle involves operation of actuator 76 of piezoelectric device 65 by cam element 108 When the crystal of the piezoelectric device 65 is struck or fully compressed, a spark of high voltage is generated between the electrodes of spark plug 30 in combustion chamber 27. As a result, the oxidizer/fuel mixture ignites, generating a rapid expansion of the combusted gases which increases the pressure on piston/driver assembly 16. At this point, manual trigger 57 is completely actuated or depressed.
The piston/driver assembly 16 shifts downwardly as viewed in FIG. 4, shearing the washer 36c (surrounding the forwardmost stud of the strip) from strip 37 and driving the forwardmost stud 36 into the work piece (not shown). While the piston/driver assembly 16 shifts downwardly, air beneath the piston/driver assembly 16 is compressed into return air chamber 11 through ports 12 and 13. That energy of piston/driver assembly 16, not expended in driving the stud 36, is absorbed by the resilient bumper 22.
The above described three operations of the tool cycle complete the drive part of the cycle. The return part of the cycle begins as manual trigger 57 begins to return toward its normal, unactuated position, under the influence of spring 59.
At this point, the fourth operation of the cycle begins. The fourth operation of the cycle entails operation of actuator 75 of pilot valve 64 by cam element 101, as the cam system 97 continues its rotation. When two-way pilot valve 64 is opened, a part of the air under pressure from return air chamber 11 is used to actuate or open exhaust valve 32. This enables the products of combustion from combustion chamber 27 to be exhausted to atmosphere. While the combustion chamber exhausted, the remainder of the return air from return air chamber 11 is channeled back beneath the piston/driver assembly 16 through passages 68 and 69, conduit 70 and passage 71, returning the piston/driver assembly 16 to its normal or prefire position. Flapper valves 21 beneath resilient bumper 22 open to permit some fresh air to enter beneath the piston/driver assembly 16 until it is balanced to atmospheric level.
Manual trigger 57 returns to its normal, unactuated position. Feeder shoe 45 and its lug 50 assure that the next forwardmost stud 36 of strip 37 is located within drive track 35 of guide body 4 as soon as piston/driver assembly 16 returns to its normal retracted position. As a result, the tool cycle is complete and the tool is ready for another cycle.
FIG. 12 is a diagrammatic representation of the various operation initiation points of cam system 120. At the 0° mark the manual trigger 57 is at rest in its normal position. When the operator actuates trigger 57, causing rotation of cam system 97, cam element 109 will operate the actuator 92a of two-way fuel valve 92 after about 15° of rotation of cam system 97. At about 25° of rotation, cam element 102 will operate actuator 89 of two-way oxidizer valve 85. At about 135° of rotation, cam element 108 will operate actuator 76 of piezoelectric device 65. At 180° the trigger is fully depressed.
When the trigger 57 is released and begins to return to its normal, unactuated condition under the influence of spring 59, cam element 101 will operate actuator 75 of pilot valve 64 when the cam system 97 has rotated about 195°. Thereafter, the cam system 97 will return to its normal, unactuated position indicated at 0°. It will be apparent to one skilled in the art that by properly arranging two-way fuel valve 92, two-way oxidizer valve 85, piezoelectric device 65 and two-way pilot valve 64 thereabout, a single cam element could be substituted for cam elements 101, 102, 108 and 109. The single cam element could be rotatively mounted in the handle 3 and caused to rotate 360° by a manual trigger and lever similar to trigger 57 and lever 113. The single cam element would operate each of actuators 92a, 89, 76 and 75 in proper timed sequence.
The tool 1 could be provided with various types of safety devices, as is well known in the art. For example, manual trigger 57 could be disabled until a workpiece responsive trip (not shown), operatively connected thereto, is pressed against the workpiece to be nailed. Alternatively, the workpiece responsive trip could be employed to close a normally open switch in the spark plug-piezoelectric device circuit. Such arrangements are well known in the art and do not constitute a part of the present invention.
It will be understood that the tool of the present invention may be held in any orientation during use. Thus, words such as "upper", "lower", "upwardly", "downwardly", "vertical", and the like are used in the above description and the claims in conjunction with the drawings for purposes of clarity, and are not intended to be limiting.
Modifications may be made in the invention without departing from the spirit of it. For example, the tool 1 could be simplified by connecting the outlets of fuel valve 92 and oxidizer valve 85 to a single passage provided with a check valve and leading to the combustion chamber. This is diagrammatically illustrated in FIG. 13. The outlet of oxidizer valve 85 is connected by conduit 118 to a passage 119 containing check valve 120 and leading to combustion chamber 27. In similar fashion the outlet of fuel valve 92 is connected to passage 119 ahead of check valve 120 by conduit 121.
The power output of the tool 1 of the present invention can be varied, by changing the size of combustion chamber 27. It will be remembered that, when fuel and combustion air are introduced into the combustion chamber 27 during the tool cycle, the piston/driver assembly 16 shifts slightly downwardly until the free end of the driver 16b contacts the head of the forwardmost stud 36 in drive track 35 of guide body 4. Thus, the size of combustion chamber 27 is determined, in part, by the position of the piston portion 16a of piston/driver asesmbly 16. As a consequence, if the forwardmost stud 36 located in drive track 35 of guide body 4 were slightly lowered, the piston portion 16a of piston/driver assembly 16 would lower an equivalent amount, enlarging combustion chamber 27 and increasing the amount of oxidizer/fuel mixture it can contain. In this way, the power of the tool would be increased. Lowering the fowardmost stud in the drive track 35 of guide body 4 can be accomplished in several ways. First of all, a different guide body and magazine could be substituted, if a power increase is desired. Another way would be to lower the entire magazine 5 with respect to the remainder of tool 1. This could be accomplished by making the attachment of the forward end of magazine 5 to guide body 4 an adjustable one. For example, the forward end of magazine 5 could ride in a pair of tracks (one of which is shown in broken lines at 4a in FIG. 4). Preferably means (not shown) are provided to lock the forward end of magazine 5 in selected adjusted positions with respect to the tracks. To this end, the opening 68 in the rearward wall of guide body 4 could be so sized as to enable the passage of studs therethrough in any of the preselected positions of magazine 5. Similarly, additional slots equivalent to slot 69 should be provided at selected positions in the guide body, such additional slots are shown in FIG. 4 in broken lines at 69a and 69b. Additional slots equivalent to slots 43 and 44 should be provided in the forward wall of guide body 4. Such additional slots are indicated in broken lines in FIG. 2 at 43a, 43b, 44a and 44b. Finally, the bracket means 5a (see FIG. 4) by which the rearward end of magazine 5 is attached to handle 3 must be made adjustable, as well.
When the size of combustion chamber 27 is enlarged in the manner just described, it will be necessary to adjust the pressure regulating screw 82 of needle valve 80 and the regulating screw (not shown) of needle valve 90, to appropriately change the fuel/air mixture. To this end, the handle 3 could be provided with indicia (not shown) indicating the proper settings for valves 80 and 90.
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A fastener driving tool powered by internal combustion of an oxidizer/fuel mixture. The tool body contains a cylinder provided with a piston/driver assembly. The cylinder is surrounded by and connected to a return air chamber. A combustion chamber, provided with an ignition device, is located at the upper end of the cylinder. A positive trigger-actuated cam system, upon actuation of the trigger, is configured to open a fuel valve to introduce a measured amount of gaseous fuel from a source thereof into the combustion chamber; to thereafter open an oxidizer valve to introduce a measured quantity of gaseous oxidizer from a source thereof into the combustion chamber; to next actuate the ignition device to combust the oxidizer/fuel mixture causing the piston/driver assembly to drive a fastener and to fill the return air chamber with air under pressure; and finally to actuate a pilot valve operating an exhaust valve eliminating products of combustion from the combustion chamber, enabling air from the return air chamber to return the piston/driver assembly to its normal position. The sources of gaseous fuel and gaseous oxidizer comprise canisters of each replaceably mounted within the tool body.
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[0001] This application is based on Japanese Patent Application No. 2009-248518 filed with Japan Patent Office on Oct. 29, 2009, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an input device, and more particularly to an input device suitable for electronic equipment having operation keys small in number.
[0004] 2. Description of the Related Art
[0005] Conventional electronic equipment contains a microcomputer to allocate a single key among a plurality of processes. The microcomputer allows switchover among a plurality of states and determines a process to be executed in accordance with a combination of the selected state and the pressed key. Therefore, the microcomputer cannot determine a process to be executed unless the state selected when a key is pressed is not identified.
[0006] For example, a conventionally known key input device includes a key matrix portion including an ID code generating circuit, and a code conversion portion. The code conversion portion performs key-scan on the key matrix portion using an X bus for strobe signal output and a Y bus for key address input. The code conversion portion takes in an ID code from the Y bus through an ID code identifying portion. In this key input device, an ID code is set by using a particular signal output from the X bus initially or at the start of key-scan to temporarily clamp a particular line of the Y bus at a prescribed logic level.
[0007] The conventional key input device outputs the ID code to the Y bus initially or at the start of key-scan and therefore cannot perform ID code setting and key-scan simultaneously. Thus, the ID code has to be set every time the microcomputer of the electronic equipment changes states. Accordingly, a prescribed time is required before key-scan is started.
SUMMARY OF THE INVENTION
[0008] In accordance with an aspect of the present invention, an input device includes: a state detection portion to detect a state of a connected external device; a signal generation portion to generate a pulse signal predetermined for the detected state; a signal detection portion responsive to detection of a pulse signal to output a state signal predetermined for the detected pulse signal; and an opening/closing portion to open/close a circuit that connects the signal generation portion with the signal detection portion.
[0009] The foregoing and other features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a block diagram showing a configuration of an input device in an embodiment of the present invention, together with a control unit of a digital still camera.
[0011] FIG. 2 shows an example of scan pulses.
[0012] FIG. 3 shows an example of the relation between the processes executed by the digital still camera, the states of the digital still camera, and interrupt terminals.
[0013] FIG. 4 is a flowchart showing an exemplary flow of a pulse generation process executed by a scan pulse output portion.
[0014] FIG. 5 is a flowchart showing an exemplary flow of a key detection process executed by a key input detection portion.
[0015] FIG. 6 is a diagram showing an exemplary input device in a modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] In the following, an embodiment of the present invention will be described with reference to the figures. In the following description, the same parts are denoted with the same reference numerals. Their names and functions are also the same. Therefore, a detailed description thereof will not be repeated.
[0017] An input device in the present embodiment is applied as a user interface of electronic equipment. Here, the input device is applied to a digital still camera as an example of electronic equipment, by way of example. A digital still camera, which is well known and of which description is not repeated here, changes between an image pickup state in which an image is picked up and a replay state in which the picked-up image is displayed, in accordance with the user's operation. In each state, a plurality of predetermined processes are executed. The processes in the image pickup state include, for example, an exposure-controlling process, an automatic focusing process, and image processing of correcting the picked-up image. The processes in the replay state include, for example, a process of deleting or editing the stored image and a process of continuously replaying images.
[0018] FIG. 1 is a block diagram showing a configuration of an input device 11 in the present embodiment, together with a control unit of a digital still camera. Referring to FIG. 1 , input device 11 includes a scan pulse output portion 21 , a key switch circuit 31 , a key input detection portion 41 , and a register circuit 51 . A control unit 61 is a device external to input device 11 .
[0019] Scan pulse output portion 21 includes an encoder 23 and a scan pulse generation portion 25 . Encoder 23 receives, from a state notification portion 73 of control unit 61 as described later, a state set in the digital still camera, in other words, a state signal indicating a state in which control unit 61 operates. This state signal is input once every time the digital still camera has its state changed. Encoder 23 outputs, to scan pulse generation portion 25 , code data predetermined for a state input from state notification portion 73 . In other words, encoder 23 stores a table in which code data is associated with each of a plurality of states, and outputs the code data corresponding to the input state to scan pulse generation portion 25 .
[0020] The number of bits of code data is not specifically limited and is set in accordance with the number of states that can be switched by the digital still camera. Here, the digital still camera may assume two states, namely, the image pickup state and the replay state. So, code data having a data length of one bit will suffice, wherein the code data corresponding to the image pickup state is “0” and the code data corresponding to the replay state is “1.”
[0021] Scan pulse generation portion 25 generates scan pulses (pulse signal) including code data received from encoder 23 . Scan pulse generation portion 25 selects one of four output terminals O 1 , O 2 , O 3 , O 4 connected with four output lines LC 1 , LC 2 , LC 3 , LC 4 , in order, and outputs scan pulses to the selected output terminal for a first prescribed period of time T 1 . Scan pulse generation portion 25 outputs scan pulses generated at intervals of a second prescribed time (T 2 ) to the selected one of the four output terminals O 1 , O 2 , O 3 , O 4 for a prescribed period of time (T 1 ). Specifically, scan pulse generation portion 25 outputs scan pulses to the selected one of the four output terminals O 1 , O 2 , O 3 , O 4 at intervals of time period T 2 for period T 1 and keeps, of the four output terminals O 1 , O 2 , O 3 , O 4 , the other three terminals to which no scan pulse is output, at a High state. Here, T 1 >T 2 . For example, given T 1 =10×T 2 , for period T 1 , ten scan pulses are output to output terminal O 1 and High is output to the other output terminals O 2 , O 3 , O 4 . For the next period T 1 , ten scan pulses are output to output terminal O 2 and High is output to the other output terminals O 1 , O 3 , O 4 . Furthermore, for the next period T 1 , ten scan pulses are output to output terminal O 3 and High is output to the other output terminals O 1 , O 2 , O 4 . Still further, for the next period T 1 , ten scan pulses are output to output terminal O 4 and High is output to the other output terminals O 1 , O 2 , O 3 .
[0022] Scan pulse generation portion 25 repeats the process of outputting scan pulses to each of the four output terminals O 1 , O 2 , O 3 , O 4 , in order, for period T 1 until the next code data is input from encoder 23 . The scan pulse is a pulse signal having a combination of a High state and a Low state in a predetermined period.
[0023] FIG. 2 shows an example of the scan pulses. Referring to FIG. 2 , the scan pulses include a start bit (Low) of one bit, code data of N bits (N is a positive integer), and a stop bit (Low) of one bit.
[0024] Returning to FIG. 1 , key input detection portion 41 includes four input terminals I 1 , I 2 , I 3 , I 4 . The four input terminals I 1 , I 2 , I 3 , I 4 are connected with input lines LR 1 , LR 2 , LR 3 , LR 4 , respectively. The potential of input lines LR 1 , LR 2 , LR 3 , LR 4 is set High by a pull-up resistor. Key switch circuit 31 includes sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 , which are connected with four output lines LC 1 , LC 2 , LC 3 , LC 4 and four input lines LR 1 , LR 2 , LR 3 , LR 4 , respectively.
[0025] For example, switch SW 11 has one end connected to output line LC 1 and the other end connected to input line LR 1 . Therefore, when switch SW 11 is pressed by the user, switch SW 11 electrically connects output line LC 1 with input line LR 1 . Switch SW 21 has one end connected to output line LC 1 and the other end connected to input line LR 2 . Therefore, when switch SW 21 is pressed by the user, switch SW 21 electrically connects output line LC 1 with input line LR 2 . Switch SW 31 has one end connected to output line LC 1 and the other end connected to input line LR 3 . Therefore, when switch SW 31 is pressed by the user, switch SW 31 electrically connects output line LC 1 with input line LR 3 . Switch SW 41 has one end connected to output line LC 1 and the other end connected to input line LR 4 . Therefore, when switch SW 41 is pressed by the user, switch SW 41 electrically connects output line LC 1 with input line LR 4 .
[0026] Key input detection portion 41 is synchronized with scan pulse output portion 21 and receives, from scan pulse output portion 21 , to which of output terminals O 1 , O 2 , O 3 , O 4 scan pulses are output. Thus, key input detection portion 41 detects that any one of switches SW 11 , SW 21 , SW 31 , SW 41 is pressed by the user while it is receiving that scan pulses are output from scan pulse output portion 21 to output terminal O 1 . Key input detection portion 41 detects that any one of switches SW 12 , SW 22 , SW 32 , SW 42 is pressed by the user while it is receiving that scan pulses are output from scan pulse output portion 21 to output terminal O 2 . Key input detection portion 41 detects that any one of switches SW 13 , SW 23 , SW 33 , SW 43 is pressed by the user while it is receiving that scan pulses are output from scan pulse output portion 21 to output terminal O 3 . Key input detection portion 41 detects that any one of switches SW 14 , SW 24 , SW 34 , SW 44 is pressed by the user while it is receiving that scan pulses are output from scan pulse output portion 21 to output terminal O 4 .
[0027] Here, a description will be made to an operation of key input detection portion 41 for period T 1 during which scan pulse generation portion 25 outputs scan pulses to output terminal O 1 , by way of example. In a state in which switches SW 11 , SW 21 , SW 31 , SW 41 are not pressed by the user, the four input terminals I 1 , I 2 , I 3 , I 4 of key input detection portion 41 are set High. When switch SW 11 is pressed by the user, output line LC 1 is electrically connected with input line LR 1 so that scan pulses are input to input terminal I 1 of key input detection portion 41 . Upon detecting the scan pulses at input terminal I 1 , key input detection portion 41 extracts code data included in the scan pulses and also detects that switch SW 11 is pressed by the user.
[0028] When switch SW 21 is pressed by the user, output line LC 1 is electrically connected with input line LR 2 so that scan pulses are input to input terminal I 2 of key input detection portion 41 . Upon detecting the scan pulses at input terminal I 2 , key input detection portion 41 extracts code data included in the scan pulses and also detects that switch SW 21 is pressed by the user.
[0029] When switch SW 31 is pressed by the user, output line LC 1 is electrically connected with input line LR 3 so that scan pulses are input to input terminal I 3 of key input detection portion 41 . Upon detecting the scan pulses at input terminal I 3 , key input detection portion 41 extracts code data included in the scan pulses and also detects that switch SW 31 is pressed by the user.
[0030] When switch SW 41 is pressed by the user, output line LC 1 is electrically connected with input line LR 4 so that scan pulses are input to input terminal I 4 of key input detection portion 41 . Upon detecting the scan pulses at input terminal I 4 , key input detection portion 41 extracts code data included in the scan pulses and also detects that switch SW 41 is pressed by the user.
[0031] Upon detecting the switch pressed by the user, key input detection portion 41 updates a switch table stored by register circuit 51 . The switch table shows whether each of sixteen switches, namely, SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 , is pressed or not. Specifically, the switch table has a storage area corresponding to each of switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 . If the value in the storage area is “0,” the corresponding switch is not pressed, and if it is “1,” the corresponding switch is pressed. The location of the storage area specifies one of switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 , and the value stored in the storage area specifies one of the pressed state and the not-pressed state.
[0032] Key input detection portion 41 further includes two interrupt signal output terminals IO 1 , IO 2 for outputting an interrupt signal. Upon detecting that any one of sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 is pressed, key input detection portion 41 outputs an interrupt signal to one of interrupt signal output terminals IO 1 , IO 2 that is predetermined corresponding to the detected code data. Here, interrupt signal output terminal IO 1 is set for code data “0” corresponding to the image pickup state, and interrupt signal output terminal IO 2 is set for code data “1” corresponding to the replay state. When code data “0” is detected, key input detection portion 41 outputs an interrupt signal to interrupt signal output terminal IO 1 . When code data “1” is detected, key input detection portion 41 outputs an interrupt signal to interrupt signal output terminal IO 2 .
[0033] Here, register circuit 51 stores which of sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 is pressed. Instead, a predetermined key code corresponding to the pressed one among the sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 may be output to control unit 61 . In this case, register circuit 51 is unnecessary.
[0034] Control unit 61 is a central processing unit (CPU) which controls the whole of the digital still camera equipped with input device 11 . Control unit 61 includes a process execution portion 71 for executing a function of the digital still camera and a state notification portion 73 for notifying input device 11 of a state of the digital still camera.
[0035] Process execution portion 71 is connected with input device 11 and includes a first port II 1 and a second port II 2 for receiving an interrupt signal. Process execution portion 71 receives an interrupt signal at one of first port II 1 and second port II 2 to read the table stored in register circuit 51 thereby to determine which of the sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 has been pressed. A process is then executed, which is specified corresponding to the one of first port II 1 and second port II 2 that has received the interrupt signal and the one of the sixteen switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 that has been pressed.
[0036] A process to be executed by process execution portion 71 is specified corresponding to each of switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 depending on a state of the digital still camera. For example, a program executed by control unit 61 includes a subroutine program associated with a combination of a state of the digital still camera and a switch (operated by the user). Control unit 61 allows the process to branch, based on the state of the digital still camera and the switch pressed by the user, thereby determining a subroutine program to be executed.
[0037] FIG. 3 shows the relation between the processes executed by the digital still camera, the states of the digital still camera, and the interrupt terminals. Referring to FIG. 3 , an item of state signal, an item of interrupt terminal, and an item of assigned process are included. If an interrupt signal is input to first port II 1 and if pressing a switch corresponding to a button A is stored in register circuit 51 , then process execution portion 71 executes a subroutine program in which a file deletion process is described. If an interrupt signal is input to second port II 2 and if pressing the switch corresponding to button A is stored in register circuit 51 , then process execution portion 71 executes a subroutine program in which a process of setting a flash lamp is described.
[0038] When an interrupt signal is input to one of first port II 1 and second port II 2 , process execution portion 71 determines a subroutine program to be executed and then executes a process only by referring to register circuit 51 to determine which switch is pressed. Therefore, it is neither necessary to determine whether the digital still camera is in the image pickup state or the replay state, nor to execute a check process for such a determination, thereby increasing the processing speed. The subroutine programs include a program in which a process of switching the states of the digital still camera is described. When executing the process of switching the states of the digital still camera, process execution portion 71 outputs a signal to state notification portion 73 to indicate the state after switching.
[0039] State notification portion 73 receives a signal indicating the state after switching from process execution portion 71 to output to input device 11 a state signal predetermined for the state after switching.
[0040] FIG. 4 is a flowchart illustrating an exemplary flow of a pulse generation process executed by the scan pulse output portion. Referring to FIG. 4 , scan pulse output portion 21 determines whether a state signal is input from control portion 61 (step S 01 ). If a state signal is input, the process proceeds to step S 02 . If not, the process proceeds to step S 03 . It is noted that immediately after the power is turned on, the process waits until an initial state signal is input.
[0041] In step S 02 , predetermined code data corresponding to the state signal is determined, and the process then proceeds to step S 03 . In step S 03 , a variable i is set to 1. Variable i is a variable for specifying the output terminal that outputs scan pulses, among output terminals O 1 , O 2 , O 3 , O 4 . Here, a sequence O(i) is used, wherein output terminals O 1 , O 2 , O 3 , O 4 are associated with sequences O( 1 ), O( 2 ), O( 3 ), O( 4 ), respectively.
[0042] In step S 04 , output terminal O(i) is set as the target of the process of outputting scan pulses. If i is set to “1,” output terminal O 1 is set as the process target. If i is set to “2,” output terminal O 2 is set as the process target. If i is set to “3,” output terminal O 3 is set as the process target. If i is set to “4,” output terminal O 4 is set as the process target.
[0043] Then, scan pulses are output to the one of output terminals O 1 -O 4 that is set as the process target (step S 05 ). The scan pulses include a Low start bit, code data bits, a Low stop bit. It is then determined whether prescribed time T 2 has passed since the scan pulse was output (step S 06 ). The prescribed time has a predetermined value set as a scan pulse transmission interval. It may be set depending on the transfer rate of the scan pulses and the bit length of the scan pulses. The process waits until prescribed time T 2 has passed. If prescribed time T 2 has passed, the process proceeds to step S 07 .
[0044] In step S 07 , it is determined whether prescribed time T 1 has passed since the initial scan pulse was output. If prescribed time T 1 has passed, the process proceeds to step S 08 . If not, the process returns to step S 05 . Prescribed time T 1 is a predetermined period of time during which the scan pulses are continuously output to the one of output terminals O 1 -O 4 that is set as the process target. The number of times a scan pulse is output to the one of output terminals O 1 -O 4 that is set as the process target may be counted, so that the scan pulses are output until the count value reaches a predetermined number of times.
[0045] In step S 08 , it is determined whether variable i is equal to “4.” If variable i is equal to “4,” the process returns to step S 03 . If not, the process proceeds to step S 09 . In step S 09 , variable i is set to a value incremented by one, and the process returns to step S 04 . This is to change the process target among output terminals O 1 -O 4 .
[0046] FIG. 5 is a flowchart showing an exemplary flow of a key detection process executed by the key input detection portion. Referring to FIG. 5 , key input detection portion 41 sets variable i to “0” (step S 11 ). Variable i is a counter for counting the number of times a start bit of scan pulse is detected.
[0047] In step S 12 , it is determined whether a start bit is detected at one of input terminals I 1 , I 2 , I 3 , I 4 . Here, it is determined whether a one-bit Low signal is detected or not. The process waits until a start bit is detected at any one of input terminals I 1 , I 2 , I 3 , I 4 . If a start bit is detected at any one of input terminals I 1 , I 2 , I 3 , I 4 , the process proceeds to step S 13 .
[0048] In step S 13 , it is determined whether variable i is equal to a threshold value T. If variable i is equal to threshold value T, the process proceeds to step S 15 . If not, the process proceeds to step S 14 . In step S 14 , variable i is set to the value incremented by one, and the process then returns to step S 12 . To distinguish the scan pulse from chattering, the scan pulse is identified by detecting a start bit T times. Here, T=4.
[0049] In step S 15 , code data is taken in. The code data is taken in by analyzing the scan pulses input following the start bit. Furthermore, it is determined whether a stop bit is detected following the code data (step S 16 ). Here, it is determined whether a one-bit Low signal is detected following the code data. If a stop bit is detected, the process proceeds to step S 17 . If not, the process returns to step S 11 . If no stop bit is detected, the start bit and the taken-in code data that have been detected until then are handled as chattering. A detection error is thus prevented. It is noted that the scan pulses may be configured only with a start bit and code data without using a stop bit.
[0050] In step S 17 , the one of input terminals I 1 , I 2 , I 3 , I 4 at which the start bit is detected in step S 12 is specified. Then, based on the specified input terminal, a switch is specified (step S 18 ). Specifically, a switch is specified based on, among output terminals O 1 , O 2 , O 3 , O 4 , the output terminal that outputs the scan pulse at the time of detection of the start bit in step S 12 in the above-mentioned pulse generation process, and the input terminal specified in step S 17 .
[0051] In step S 19 , it is set in the register circuit that the specified switch is pressed. In the next step S 20 , a predetermined state for the code data taken in in step S 15 is determined. Here, code data “0” corresponds to the image pickup state and code data “1” corresponds to the replay state.
[0052] Then, of interrupt signal output terminals IO 1 , IO 2 , the one that is predetermined for the determined state is determined. Here, interrupt signal output terminal IO 1 corresponds to the image pickup state, and interrupt signal output terminal IO 2 corresponds to the replay state. In step S 22 , an interrupt signal is output to the one of interrupt signal output terminals IO 1 , IO 2 that is determined in step S 21 . The process then ends.
<Modification>
[0053] FIG. 6 is a diagram showing an exemplary input device in a modified embodiment. Referring to FIG. 6 , an input device 11 A in a modified embodiment differs from input device 11 shown in FIG. 1 in that encoder 23 and register circuit 51 are replaced by an encoder 23 A and a register circuit 51 A, respectively. Input device 11 shown in FIG. 1 receives a state signal from control unit 61 , whereas encoder 23 A of input device 11 A in the modified embodiment detects a connection state of a lens 81 , a flash lamp 83 , a memory card 85 , and a charger 87 mounted on the digital still camera and detects a state depending on a combination of the connected lens 81 , flash lamp 83 , memory card 85 , and charger 87 . Lens 81 , flash lamp 83 , memory card 85 , and charger 87 mounted on the digital still camera are devices external to input device 11 A.
[0054] Encoder 23 A specifies a combination of the connected devices (connection state) by detecting which of lens 81 , flash lamp 83 , memory card 85 , and charger 87 is connected to the digital still camera. Encoder 23 A outputs, to scan pulse generation portion 25 , code data predetermined for the specified combination. In other words, encoder 23 A stores a table in which a plurality of combinations are each associated with code data, and encoder 23 A outputs the code data corresponding to the specified combination to scan pulse generation portion 25 . Here, since there are six combinations in which lens 81 , flash lamp 83 , memory card 85 , and charger 87 are connected, code data having a data length of four bits will suffice.
[0055] Register circuit 51 A stores switch tables corresponding to the respective connection states of lens 81 , flash lamp 83 , memory card 85 , and charger 87 . Specifically, six switch tables are stored corresponding to the respective six connection states. Key input detection portion 41 specifies a switch table corresponding to the code data, from the six switch tables, and overwrites the corresponding storage area of the specified switch table. The corresponding storage area is the storage area allocated to the pressed switch among switches SW 11 -SW 14 , SW 21 -SW 24 , SW 31 -SW 34 , SW 41 -SW 44 .
[0056] It is noted that register circuit 51 A in the modified embodiment may be applied to the above-noted input device 11 . Conversely, register circuit 51 of the above-noted input device 11 may be applied to input device 11 A in the modified embodiment. In this case, six interrupt signal output terminals are required corresponding to the six connection states.
[0057] In the present embodiment, scan pulse generation portion 25 selects one of the four output terminals O 1 , O 2 , O 3 , O 4 in order and outputs a plurality of scan pulses to the selected output terminal for a prescribed period of time T 1 .
[0058] Alternatively, one scan pulse may be output to the four output terminals O 1 , O 2 , O 3 , O 4 , in order. Specifically, one scan pulse is output once to output terminal O 1 , thereafter one scan pulse is output once to output terminal O 2 , then one scan pulse is output once to output terminal O 3 , and then one scan pulse is output once to output terminal O 4 . In this case, key input detection portion 41 identifies the scan pulse on condition that a start bit is detected successively T times at each of the four input terminals I 1 , I 2 , I 3 , I 4 , similarly as described above.
[0059] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
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In accordance with an aspect of the present invention, an input device includes: a state detection portion to detect a state of a connected external device; a signal generation portion to generate a pulse signal predetermined for the detected state; a signal detection portion responsive to detection of a pulse signal to output a state signal predetermined for the detected pulse signal; and an opening/closing portion to open/close a circuit that connects the signal generation portion with the signal detection portion.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority to PCT/EP01/12547 filed 30 Oct. 2001 and to German Application No. 200 18 560.8 filed 30 Oct. 2000, and is further related to U.S. application Ser. No. 10/836,559 filed Apr. 30, 2004; U.S. application Ser. No. 10/489,573 filed Aug. 5, 2004; U.S. application Ser. No. 10/489,533 filed Aug. 5, 2004; U.S. application Ser. No. 10/489,583 filed Aug. 5, 2004; and U.S. application Ser. No. 10/489,584 filed Aug. 5, 2004.
BACKGROUND OF THE INVENTION
The invention relates to a control and supply system for electrical devices, comprising at least one voltage supply and control device above sea level, a subsea cable connecting voltage supply and control device with the electrical devices, and a control and actuating device which is associated essentially in situ with the electrical devices.
Such control and supply systems are used, for example, in the production of natural gas and oil. In this respect, the application may take place with terrestrial and maritime drilling wells.
With maritime wells one part of the control and supply system is arranged on a platform above the sea surface. This part is in particular a voltage supply and control device which is connected via a subsea cable to the control and actuating device below the sea surface or also on the sea bed. The control and actuating device is connected to various electrical devices, such as motors, electrical actuators and similar equipment via appropriate connecting lines.
With this type of control and supply system known from practice, AC voltage is transmitted through a subsea cable, whereby the amplitude and frequency of the AC voltage is already selected such that, for example, on the end of the cable associated with the electrical devices a suitable supply voltage for the devices is provided. For the direct control of each device a separate subsea cable can be provided for each device. The data transmission also occurs via separate subsea cables.
A disadvantage with this known control and supply system is that, for example, for a supply of an electrical device with 240 VAC and with an original voltage feed of 600 VAC for the transmission of the appropriate power to the electrical devices and, for example, a length of subsea cable of 30 or 50 km, a cross-sectional area of 100 to 200 mm 2 is needed for the cable. In addition, data lines are required, so that a subsea cable with a substantial diameter arises.
In the above it has been assumed that 240 VAC is sufficient for the electrical devices. However, it has now been found that higher voltages are required, for example, in order to be able to actuate servomotors as electrical devices with higher power, for example, to close valves in the production of natural gas or oil in a maximum time period of one minute. With the application of such electrical devices supplied with a higher voltage the cross-sectional area of the subsea cable with the known control and supply system would increase still further.
In addition, it has been found in practice that on starting a servomotor as an electrical device and in particular for servomotors with a higher power, even with a slow starting process, a return signal occurs via the subsea cable to the voltage supply and control device indicating the starting process of the servomotor as a short circuit at the end of the cable. This leads to the switching off of a system automatically protected against short circuit. Furthermore, with the previously described control and supply system an efficiency for the overall system of only 27% is obtained referring to the output power.
With another control and supply system known from practice, transmission of AC voltage also occurs through the subsea cable. However, with this system an AC voltage, for example, at 10,000 VAC is transmitted via the subsea cable and at the control and actuating device it is reduced, for example, by a transformer to the voltage values required by the electrical devices. In addition, a number of power capacitors must be used to smooth the voltage again after the reduction. In order to be able to reduce, where required, the conductor cross-sectional areas for the subsea cable with this other known system, a power factor correction is also implemented to obtain an adequate efficiency for the overall system. Further devices, which are very complex and expensive, are needed for this correction.
However, even with the complete expansion of the previously mentioned system, the efficiency normally is less than 70% and the cross-sectional areas for a conductor in the subsea cable amount to about 16 or 26 mm 2 for a length of 30, or respectively 50 km.
BRIEF SUMMARY OF THE PREFERRED EMBODIMENTS
The object of the invention is to improve a control and supply system of the type mentioned at the beginning such that with less complexity, higher efficiency and better system usage, supply is possible over larger distances.
This object is solved in relationship with the characteristics of the generic term of claim 1 such that the voltage supply and control device for the production of a DC voltage for feeding into the subsea cable comprises at least one AC/DC converter, the control and actuating device is associated with at least one DC/DC or DC/AC converter for converting the DC voltage transmitted by the subsea cable into a DC voltage or AC voltage and the voltage generated thereby can be transmitted to the electrical devices via the connecting lines. This means that according to the invention DC voltage is transmitted via the long subsea cables, whereby the conversion from AC voltage into DC voltage or vice versa from DC voltage into AC voltage only takes place at the ends of the subsea cable. With DC voltage and the corresponding DC current, only real power is transmitted via the subsea cable and not apparent power. This means that the power factor is 1. Due to the DC voltage transmission along the subsea cable, even with high voltages only slight losses are present in comparison to a transmission of AC voltage with previously known systems.
Furthermore, with the transmission of DC voltage only small cross-sectional areas arise for a conductor in the subsea cable which may be only one tenth or less of the cross-sectional areas for the transmission of AC voltage.
Due to the DC/DC or DC/AC converter in the area of the control and actuating device, a corresponding conversion of the DC voltage takes place into the required DC or AC voltage values, such as for example, 240 V or 300 V with the appropriate frequency, for the electrical devices such as motors, actuators and similar equipment.
The system according to the invention is therefore distinguished by its simplicity and higher efficiency (at least 70%), whereby a significant cost saving can be obtained solely by the significant reduction of the cross-sectional area of the conductors in the subsea cable.
A simple voltage source for the system, which can also normally be used for other applications, can be seen in that an AC voltage source is connected to the supply voltage and control device for the supply with a three-phase AC voltage source.
With the previously known systems it is also possible to transmit data between the voltage supply and control device and the control and actuating device. Normally, a separate cable is used for this.
According to the invention, another advantage arises in that the DC voltage transmission along the subsea cable is free of any high frequencies and therefore voltage frequencies can be modulated onto the DC voltage in a simple manner for data transmission. Data modulation can especially take place in that the voltage supply and control device and the control and actuation device each include at least one data modulation device.
An effective type of data feed can be seen in that the data modulation device of the voltage supply and control device is arranged downstream from the DC/DC or AC/DC converter at the surface.
An effective type of data feed can be implemented if the data modulation device of the voltage supply and control device is arranged downstream from the DC/DC or AC/DC converter at the surface.
In order to be able to receive or feed in data in a simple and analogous manner also in the area of the control and actuation device, the data modulation device of the control and actuation device can be positioned upstream from the DC/DC or DC/AC converter located subsea.
In this way the data is fed in and also obtained from the DC voltage.
In order to prevent the occurrence of high currents and, where applicable, of damage to the relevant electrical devices, especially on the sea bed, an overcurrent control device can be assigned to the DC/DC or DC/AC converter.
With a DC/DC converter on the sea bed the high DC voltage of a number of thousands of volts fed from the surface of the sea is split up into appropriate DC voltages for the supply of the individual devices on the sea bed.
In order to be certain that the electrical devices are supplied with suitable voltage values, the DC/AC converter can be inductively coupled with an AC voltage measurement device, with a voltage shunt regulator. Due to the voltage shunt regulator, the system can, for example, run under full voltage also before the actuation of the electrical devices, whereby the voltage shunt regulator takes over the dynamic load regulation and then can reduce the voltage to appropriately low values.
Due to the inductive coupling, it is established as a further characteristic of the invention that suitable plug connections or other connections between subsea cables and electrical devices are not operated with DC voltage. It is generally known that even slight moisture is hazardous for the transmission of DC voltage and especially salt water acts as a galvanic element with DC voltage and would very quickly damage metallic contact surfaces. In order to keep the expense of such connections low, the inductive coupling takes place below sea level and the following transmission of the voltage can utilize AC voltage for which the usual, known maritime electrical connectors can be used.
By using the usual electrical connectors, it is also possible for all the connected parts to be recovered and to be fetched from below sea level and, for example, to service them and reuse them later. According to the invention a fixed and non-releasable connection between the subsea cable and appropriate devices is not required.
For the inductive coupling a transformer can be used, which directly carries out the conversion of the DC voltage into the AC voltage values for the electrical devices.
Such a transformer may comprise two separable, largely symmetrical and mutually associated coil half-cores.
In order to be able to simultaneously interchange data over the air gap between the coil half-cores, a data modulation device can be assigned to each coil half-core for the transmission of data.
In order to control and monitor the conversion of the DC voltage into AC voltage and to control and monitor at least the appropriate data modulation devices of the coil half-cores, a coupling control device appropriate for controlling the data modulation devices, the DC/AC converter and/or the AC voltage measurement device can be assigned to each coil half-core. A return signal to the voltage supply and control device for regulating the DC voltage can be provided from the AC voltage measurement device, whereby the return signal occurs via the appropriate coupling control devices, data modulation devices for the coil half-cores, data modulation device of the control and actuating device, subsea cable and data modulation device of the voltage supply and control device. In this way a continuous bidirectional data interchange between the voltage supply and control device and the control and actuation device is possible.
With a simple embodiment without further control devices, the AC voltage measurement device can be connected to the electrical devices for their supply.
The AC voltage measurement device can, for example, measure an amplitude of the AC voltage.
In some embodiments, it is advantageous if the AC voltage supplied by the DC/AC converter is, for example, a rectangular wave voltage. With this voltage the various electrical devices can be supplied with a stable voltage and with sufficient power.
A separate voltage stabilization, for example, using a Zener diode arrangement is no longer necessary due to the AC voltage measurement device with voltage shunt regulator according to the invention, because the AC voltage provided by this circuit is already statically and dynamically stabilized.
For the transmission of the DC voltage and also the electrical signals along the subsea cable, the cable can be advantageously formed from coaxial conductors. These exhibit optimum properties with regard to attenuation and immunity with regard to radiated noise and they enable a high data transmission rate of at least 100 to 600 kBaud. Furthermore, bidirectional transmission of data along the subsea cable can also be carried out simply.
The transformer can be realized such that the air gap between the two coil half-cores is, for example, at the most 4 mm or especially at the most 2 mm. In addition, appropriate materials for the coil half-cores can be used which are not susceptible to attack by sea water, such as arrangements of corrosion-resistant transformer steel sheet or plastic encapsulated magnetic powder mixtures for the appropriate coil core materials.
In order to be able to also pass data in the direction of the voltage supply and control device directly from the electrical devices or the AC voltage measurement device, the voltage shunt regulator can be realized bidirectionally.
Due to the application according to the invention of DC voltage or DC current and the resulting possible small cross-sectional areas of the conductors in the subsea cable, there is also the possibility that for each electrical device a separate connecting conductor can be provided in the subsea cable. In this relationship it must be noted that an electrical unit, for example, a single motor or a single actuator can also be a suitable tree structure or group of electrical motors, actuators or other electrical devices.
A suitably simple coupling of data—also multi-channel—can be realized in that the system exhibits a multiplexer device for data transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following an advantageous embodiment of the invention is explained in more detail based on the figures enclosed in the drawing. In the figures, like reference characters refer to the same components throughout the specification.
The following are shown:
FIGS. 1 a - 1 c show a schematic diagram of various control and supply systems as a comparison, whereby FIGS. 1 a and 1 b are known in practice and whereby the control and supply system according to the invention is illustrated in FIG. 1 c; and
FIG. 2 shows a block diagram of the control and supply system according to the invention as in FIG. 1 c.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With the control and supply system according to FIG. 1 a , a voltage supply and control device 3 with an appropriate voltage source and multiplexer device 25 is arranged above the surface of the sea 4 . The voltage supply occurs via AC voltage, which is transmitted directly via a subsea cable 5 to a control and actuating device 6 . This is arranged below sea level and is connected via connecting lines 26 to appropriate electrical devices 2 or electrical units 24 . Such an electrical unit 24 may be formed by a group of electrical devices 2 , which, for example, are arranged in the form of a tree structure and are controlled and actuated on a common basis.
A data cable 27 is provided for the data transmission between the multiplexer device 25 of the voltage supply and control device 3 and the control and actuating device 6 . The data cable 27 is preferably composed of coaxial conductors.
Normally, an AC voltage of a maximum of 600 VAC is transmitted along the subsea cable 5 . For the supply of the appropriate electrical devices with 240 VAC and appropriate power, cross-sectional areas of at least 175 mm 2 for appropriate conductors are required in the subsea cable for, for example, a length of 50 km.
The control and actuation device 6 includes at least one motor actuation device 31 and a control system 32 . The various motors as electrical devices 2 can be used here for the actuation of valves, BOPs (blow-out preventers) and similar equipment which is used for the production of mineral oil or gas on the sea bed.
With the other known control and supply system according to FIG. 1 b transmission of AC voltage along the subsea cable 5 also occurs. In this case however a voltage of a maximum of 10,000 VAC is transmitted which is reduced before the control and actuation device 6 by a suitable transformer 33 to the voltage values required for the electrical devices. Also, with this known system a separate data conductor 27 is provided as a coaxial cable or similar cable. The control and actuating device 6 according to FIG. 1 b requires expensive power capacitors 34 in order to smooth the reduced AC voltage appropriately. In addition, with this system, as with the system according to FIG. 1 a , power factor correction devices are needed to lower the apparent power of the system. Such correction devices are normally quite expensive and consist of capacitors or similar.
With the system according to FIG. 1 b and for appropriate voltage values and powers for the electrical devices on the sea bed, conductor cross-sectional areas in the subsea cable of, for example, at least 75 mm 2 arise for a length of 50 km or with power factor correction at least a cross-sectional area of 26 mm 2 for a 50 km length.
According to the invention and as in FIG. 1 c , AC voltage is not transmitted via a subsea cable 50 , but instead DC voltage is used. In FIG. 1 c , a voltage supply and control device 300 comprises at least one AC/DC converter 7 , which converts a suitable AC voltage from an AC voltage source 9 , see FIG. 2 , into DC voltage. In FIG. 1 c , a control and actuation device 600 comprises a DC/DC or DC/AC converter 8 for the conversion of the DC voltage into DC or AC voltage. Since, according to the invention, a DC voltage is transmitted through the subsea cable 50 , correspondingly no transmission of high frequency voltages occurs, so that signals for data transmission can be modulated onto the DC voltage in a simple manner. This takes place through a multiplexer device 250 and through an appropriate cable coupler 34 . Demodulation of the data occurs appropriately in the area of the control and actuation device 600 .
With the implementation of the converter 8 as DC/DC converter, a conversion of the high DC voltage transmitted through the subsea cable 50 into the DC voltages required for the supply of the appropriate device on the sea bed occurs. It must be noted that with a DC voltage supply of the device at the sea surface, a suitable data interchange with this device is simplified, because appropriate data signals can be modulated onto the DC voltage signal in a simple manner.
The control and supply system 100 according to FIG. 1 c is described in more detail based on a block diagram in FIG. 2 .
With the embodiment of the control and supply system 100 according to the invention and as in FIG. 2 , a voltage supply and control device 300 is arranged above the sea surface 4 and a control and actuation device 600 below the sea surface 4 . The link between these two is realized by a subsea cable 50 .
The voltage supply and control device 300 comprises at least one AC/DC converter 7 and a data modulation device 10 . Furthermore, a surface control device 28 , through which the control of the AC/DC converter 7 and also of the data modulation device 10 occurs, is assigned to the AC/DC converter 7 and the data modulation device 10 .
The voltage supply and control device 300 is connected to an AC voltage source 9 which provides a three-phase AC voltage. Furthermore, the voltage supply and control device 300 is connected to a data transmission device 11 which can be positioned remote from the voltage supply and control device 300 , but which is still part of the control and supply system 100 . The control of the system and its monitoring can occur through the data transmission device 11 .
The arrows shown between the various units in the system indicate through the arrow direction a transmission of voltage or data, whereby generally a bidirectional data transmission is possible.
The control and actuation device 600 is positioned below the sea surface 4 and, for example, positioned on the sea bed. It comprises a data modulation device 12 for demodulation of the data transmitted through the subsea cable 50 , but also for the modulation of appropriate data onto the voltage transmitted through the subsea cable 50 when such data is transmitted in the reverse direction from the control and actuation device 600 to the voltage supply and control device 300 .
Following the data modulation device 12 , the control and actuation device 600 comprises a DC/DC or DC/AC converter 8 . Using a DC/AC converter, the DC voltage transmitted through the subsea cable 50 is converted back into an appropriate AC voltage. An overcurrent control device 13 is assigned to the DC/AC converter 8 . Following conversion of the DC voltage into AC voltage by the DC/AC converter 8 , an inductive transmission of the AC voltage occurs to an AC voltage measurement device 14 . The inductive transmission occurs through a transformer 16 consisting of two coil half-cores 17 , 18 . An air gap 23 is formed between these coil half-cores.
The AC voltage measurement device 14 is used for the determination of amplitude values of the AC voltage. As shown, a voltage shunt regulator 15 is included with the AC voltage measurement device 14 . The voltage shunt regulator 15 provides an appropriate static and dynamic stabilization of the AC voltage. In some embodiments, the voltage shunt regulator 15 is bidirectional and, together with the AC voltage measurement device 14 , is positioned on the output of the transformer 16 . In this manner, a stabilized AC voltage is passed to a subsea voltage source 30 to which the various electrical devices 200 or units 240 are connected via electrical connecting lines 260 .
A data modulation device 19 , 20 as well as a coupling control device 21 , 22 is assigned to each coil half-core 17 , 18 . The transmission of data occurs via the data modulation devices 19 , 20 . The coupling control devices 21 , 22 are used for the control of the various data modulation devices 12 , 19 , 20 as well as the AC voltage measurement device 14 with voltage shunt regulator 15 . Furthermore, the coupling control devices 21 , 22 are used for the interchange of data, for example, with the AC voltage measurement device 14 with voltage shunt regulator 15 and/or, for example, with a subsea electronic module 29 . This electronic module contains the appropriate electronics for controlling the various items of equipment below sea level and in particular on the sea bed, such as valves, blow-out preventers, actuators and similar equipment. The appropriate electronics is contained redundantly in the electronic module.
In the following the functioning principle of the control and supply system 1 according to the invention is briefly described based on FIG. 2 .
According to the invention, supply of the control and actuation device 600 occurs with DC voltage through the subsea cable 50 . Here, the DC voltage is converted to AC voltage by an appropriate DC/AC converter 8 only when it reaches the end of the long subsea cable. Above the surface of the sea a three-phase AC voltage is converted by an AC/DC converter to, for example, an output voltage from 3000 to 6000 V. The voltage value depends on the power requirements of the system.
Then, the stable and filtered DC voltage is passed to coaxial conductors in the subsea cable, whereby first data signals are modulated onto the voltage via a suitable data modulation device such as a modem or similar device.
Since coaxial conductors exhibit optimum properties with regard to attenuation and electrical noise, high data transmission rates of at least 100 to 600 kbaud are possible using such conductors.
On the sea bed or below the surface of the sea a demodulation of the data signals occurs using a suitable data modulation device, again such as a modem. Then, the voltage is converted by a DC/AC converter into, for example, a rectangular wave voltage of 300 V with a frequency of 20 kHz. This AC voltage can be transmitted over normal connection equipment to the various electrical devices. Only slight filtering is required without large electrolytic capacitors. The transformer 16 used for the conversion of the AC voltage of the DC/AC converter to the appropriate voltage values comprises two coil half-cores 17 , 18 , which are separated by an air gap. The coil half-cores are assigned to one another, separable from one another and are formed mutually symmetrically. This transformer provides the inductive coupling.
Then follows a measurement of the amplitude of the rectangular wave voltage by the AC voltage measurement device 14 , to which furthermore a voltage shunt regulator 15 is assigned. A static and dynamic stabilization of the output voltage is largely provided by these two devices. Appropriate losses from the transformer and other devices in the control and actuation device 6 can be dissipated directly through contact with the sea water via appropriate wall construction on the device.
Data transmission from the measurement device 14 via the data modulation device 20 and 19 and via the additional data modulation device 12 and back to the voltage supply and control device 300 is possible for regulation of the voltage supply.
Using appropriate calculations for the required voltage values and powers, a conductor cross-sectional area of only approximately 2 mm 2 arises for, for example, a length of 50 km of subsea cable with the voltage control and supply system according to the invention. This is a substantially lower cross-sectional area than with systems known in practice, see FIGS. 1 a and 1 b.
In addition, high data transmission rates are possible due to the simple modulation and demodulation with respect to the DC voltage and the coaxial cable used. Through the devices used in the system according to the invention a stable supply voltage and high system reliability arise.
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A control and supply system for electrical devices comprises at least one voltage supply and control device above sea level, a subsea cable connecting the voltage supply and control device with the electrical devices, and a control and actuating device which is associated essentially in situ with the electrical devices. The control and supply system allows supplies over larger distances, uses fewer devices, obtains higher efficiency and makes better use of the system. In order to achieve this, the voltage supply and control device comprises at least one AC/DC converter for producing a direct voltage in order to feed the subsea cable. The control and actuating device is associated with at least one DC/DC or DC/AC converter for converting the DC voltage transmitted by the sub-sea cable into a DC voltage or an AC voltage. The voltage generated thereby can be transmitted to the electrical device via a connecting line.
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PRIORITY CLAIM
[0001] The present application is a National Phase entry of PCT Application No. PCT/GB2014/053426, filed Nov. 19, 2014, which claims priority from EP Patent Application No. 1317987.4, filed Oct. 11, 2013, and GB Patent Application No. 13250127.1, filed Dec. 13, 2013, each of which is hereby fully incorporated herein by reference.
BACKGROUND
[0002] This disclosure relates to improvements to the handover process that takes place when a mobile communications device (user terminal) is required to cease communicating with a core network through one base station and begin communication through another base station. The most common reasons for such handovers to be required are because either the user terminal or the base station detects deterioration of the signal quality on the wireless communications link between them. This can be because the mobile device is moving out of range of the base station, but other changes in the wireless environment, such as changes in congestion or interference levels, may also make a handover appropriate. Handover may also occur when a user “roaming” on a network other than his “home network” (the one to which he subscribes) moves into range of a base station of his home network: in such a case a handover to the home network is desirable as soon as signal quality between the user terminal and the home network meets a predetermined threshold, regardless of the signal quality on the other network, because this will allow the user to use any facilities specific to his “home” network, and avoid paying the higher charges usually required for connection through a network other than the user's home network.
[0003] Unless the context requires otherwise, the term “base station” should be interpreted in this specification to mean any device or apparatus with which a terminal may communicate wirelessly in order to allow the terminal to communication with a backhaul connection to a core communications network. It includes, for example, access points (wireless routers) for “WiFi” (IEEE 802.11 standard) access networks, as well as the base stations used in cellular telephony.
[0004] The decision to initiate a handover, and the selection of a new link to which to hand over, is typically based on signal strength—thus, of the base stations signaling availability (having capacity to accept a connection and authorized to make connection with the mobile unit) a connection is established with the base station generating the strongest signal.
[0005] Handover can be between two cellular base stations, and in such cases is usually relatively straightforward when both base stations operate according to the same protocol. In many cases both stations are controlled by the same base site controller, which can coordinate the process. In a cellular system with permanent base stations, it is conventional to maintain a “neighbor list” for each base station which can be used to inform the mobile unit of the base stations to which handover is most likely to be possible.
[0006] However, increasingly, handsets are capable of operation in two or more different radio access technologies, for example cellular (UMTS (3G) and its packet data protocol GPRS) and WiFi (IEEE 802.11), and it is possible that a handover may be required between two base stations operating on different radio access technologies. One particular scenario occurs when a user device which has been working to an indoor short-range base station, operating on WiFi protocols, is to continue the session after leaving the premises, and therefore the range of the base station. Even within the cellular network, difficulties can arise because of the ongoing process of upgrading mobile networks from 2G (2 nd generation) to 3G to 4G, which can result in neighboring base stations having different capabilities. For example some base stations may be not be capable of supporting both circuit-switched and packet-switched traffic.
[0007] In existing systems, loss, or deterioration, of contact with the currently-serving base station leads to an attempt by the mobile unit to seek a strong signal from another base station to which the mobile unit has access rights, and to arrange handover to that base station from the currently-serving base station. However, by relying simply on signal strength, a loss of service quality may arise because of a deterioration in other properties. For example, for a voice call (for example using VoIP—Voice over Internet Protocol) or VoLTE (Voice over Long Term Evolution Protocol), low latency and jitter are important characteristics, whereas for gaming or video streaming applications, high bit rate is a priority.
[0008] It is known, for example from patent specifications US2003/069018 (Matta), US2007/026861 (Kuhn) and WO2011/033173 (Valtion), to provide a ranking of neighbor base stations in terms of “quality of service” parameters, to allow the user to select a suitable candidate for handover. This requires the user to be familiar with the capabilities required for the applications running on the handset at the time, including any background applications.
SUMMARY
[0009] A handover process monitorss an initial bearer link between a user terminal and a first base station; and when a requirement for potential handover is identified, a base station to form a preferred bearer link to the user terminal is selected from a plurality of candidate base stations. According to embodiments, the selection is made by determining the nature of the session traffic currently being handled by the initial bearer link, retrieving capability profile information relating to the capabilities of the candidate base stations, selecting a base station having a capability profile suited to handling the session traffic to be carried by the preferred bearer link, and establishing a handover and establishing a handover of the user terminal to the selected base station.
[0010] The criteria may comprise any of, or a combination of: bearer type, Quality of Service Class identifier (QCI), and the actual applications in use. Other criteria may also be used.
[0011] As is conventional, a requirement for handover may be identified in consequence of deterioration of signal strength, or an increase in interference or congestion on the initial bearer link.
[0012] Embodiments therefore modify the default behavior of the system in selecting a handover base station by using profile information to determine which (if any) of the candidate base stations support the services to be carried on the bearer link.
[0013] For example, a customer running a voice session over a wifi connection may not be handed over onto a cellular operator's network if there is no suitable radio access technology available from the cellular operator in that location. It may be preferable to drop the call when the wifi connection signal is lost, or to select an alternative cell/access network.
[0014] Embodiments improve signaling efficiency by avoiding unnecessary signaling to the target cell and optimization of the customer experience, by selecting the optimal cell to hand over to for a particular application and subscriber.
[0015] In a first embodiment the process is operated in the base station management system of a cellular network, by assessing the capabilities of the individual candidate base stations, recorded in a central database, and selecting one of the candidate base stations in accordance with selection criteria based on the application or applications currently being carried over the bearer link.
[0016] In a second embodiment the process is controlled by the user terminal, which identifies the capabilities of individual base stations, for example by interrogation or by test exchanges of data, and selecting one of the candidate base stations in accordance with selection criteria based on the application or applications currently being operated by the user terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Embodiments will be described, by way of example, with reference to the drawings, in which:
[0018] FIG. 1 depicts the relevant functional elements of a wireless base station configured to operate according to an embodiment.
[0019] FIG. 2 is a flow chart providing an overview of the process according to an embodiment.
[0020] FIG. 3 is a flow diagram depicting the principal functions performed during operation, according to an embodiment.
[0021] FIG. 4 depicts the decision process, and the inputs controlling that process, in more detail, in a situation in which the handover request is initiated by the base station, according to an embodiment.
[0022] FIG. 5 lists the standardized QCI characteristics from 3GPP Standard 23.203 Section 6.1.7, which are used to define the handover criteria used in implementing embodiments.
[0023] FIG. 6 depicts a first illustrative example of the decision process according to an embodiment.
[0024] FIG. 7 depicts a second illustrative example of the decision process, using a different weighting, according to an embodiment.
[0025] FIG. 8 depicts the final stage in the target cell selection process according to an embodiment.
[0026] FIG. 9 depicts a variant of FIG. 4 in which the handover request is controlled by the base station but initiated by the user terminal according to an embodiment.
DETAILED DESCRIPTION
[0027] FIG. 1 depicts a wireless base station 2 , which may be a cellular base station or a base station for a WLAN (Wireless Local Access network), having the ability to hand over a wireless communication session with a handset 1 (e.g., a voice call, or a data session, or a video stream) to another wireless base station base station.
[0028] The wireless base station 2 comprises a wireless interface 3 for communicating with one or more user terminals 1 , and a network interface 5 for connection through a backhaul link 6 to a network. Signal processing 4 (e.g., a modem) is provided for conversion between the signals carried over the wireless interface 3 and the network interface 5 .
[0029] A handover management system 7 interacts with the wireless interface 3 and the network (through interface 5 ) to arrange for user terminals 1 to disconnect from the base station 2 and reconnect to another, (or vice versa) according to circumstances.
[0030] In some embodiments the base station 2 maintains a database 14 of data relating to other base stations, these being selected to be the stations most likely to be involved in a handover, based for example on geographical position, or on historical data on previous handovers. The data store is maintained by a data exchange processor 9 , which may also pass data relating to the current base station 2 over the backhaul 6 to maintain the neighbor lists of other base stations.
[0031] The handover management system 7 interacts with a system 23 for identifying applications being used, or being set up to be used, on the link between the user terminal 1 and the base station 2 . In this embodiment this function is performed by monitoring the session traffic ( 13 ) for QCI values (QoS class indicators) characteristic of different applications.
[0032] A weighting processor 61 uses the neighbor data 14 and application data 23 to generate weighting values for each candidate base station, which is used by a selection processor 10 to control the handover management system 7 .
[0033] FIG. 2 provides an overview of the operation of the process. This process may be controlled by the base station, as shown in FIG. 1 , or by the handset. In normal use, ( 90 ) the handset 1 is connected to an initial base station 2 . Certain trigger conditions can occur, for example cell overload 91 , a fall in signal quality 92 , caused by interference or movement of the user terminal, or the starting up of a new application 93 by the user terminal, requiring a higher bandwidth or other changes in connection. These can be used to initiate the handover process.
[0034] If a new application 93 is the trigger, the system first determines whether the QoS (quality of service) parameters on the existing connection are adequate for this service (at 94 ) and takes no further action if this is the case. Otherwise, or if the trigger 91 , 92 is some change in the link quality, the QCI (QoS Class Identifier) associated with the application being run on the connection is determined (or the most stringent QCI, if more than one application is in operation) (at 23 ). Data ( 21 , 22 ) relating to the capabilities of the current base station 2 and data ( 11 , 12 ) relating to the capabilities of one or more candidate base stations is then applied to a weighting function ( 60 ) dependant on the QCI required, and the base station with the best score is identified ( 61 ). The data 11 , 12 may be collected during the handover process, or may have been harvested in advance.
[0035] This best score is compared with a threshold value ( 95 ) which is a minimum value associated with the applications to be run. If the score fails to meet the threshold the call (or the relevant application) is dropped ( 96 ). Otherwise, if the currently serving base station 2 has the highest score ( 97 ) then no handover takes place. Otherwise, handover 7 to the best-scoring base station is initiated.
[0036] In some instances, particularly when handing over from one operator to another (“roaming”), an uninterrupted “seamless” handover is not possible and the session has to be released and a new session initiated on a re-directed route, requiring a new IP address. In some applications with a very low latency threshold, in particular conversational voice applications (QCI 1) such as VoLTE which have little or no buffering, this can lead to an unacceptable gap in communication. In such a situation it can be preferable to maintain the session on the original connection despite the deterioration in call quality. Thus if it is determined that QCI=1 ( 98 ) and the handover can only be performed by “release and redirect”, the session remains in operation with the original base station.
[0037] FIG. 3 illustrates the handover decision logic 10 in more detail. It receives signal strength inputs 11 , 21 relating to the signal strengths of the serving cell and one or more cells that are candidates for handover. Further inputs 12 , 22 relates to the loading on each candidate cell, that is to say what capacity it has to handle a session with a further user terminal.
[0038] A further input 13 provides the QCI (Quality of Service (QoS) Class Identifier) values for each bearer. Further data 14 stored with the handover decision logic 10 includes additional information about the capabilities of neighbor cells. Conventionally such information includes features such as the radio access technology and frequencies used by the different cells.
[0039] In operation of the first embodiment, as shown in FIG. 4 , when a mobile handset, initially in communication with a base station, moves away from the base station, or there is a source of interference, a loss of signal strength (input 21 ) or an overload condition 22 is detected. In response to this detected condition, a handover decision process 20 is initiated in order to select a new base station for handover using the handover decision logic 10 . Conventionally this determination of the next base station is based on an evaluation of the signal strengths ( 11 ) and current processing loads ( 12 ) of all the potential handover target base stations.
[0040] As different base stations have different capabilities for handling data services, according to the invention the process also takes into account further capabilities of the target cells (e.g., ability to serve specific QCI values depending on permanent features such as backhaul capacity.
[0041] The base station or user terminal operating the process also monitors the session to be handed over to identify the application in use (input 23 ), so that it can determine the type of application being used by the connection ( 23 ). The handover decision logic 10 determines the QCI class of each application and, depending on the QCI values of the application in use, selection of a target handover cell is performed either on conventional principles (at 15 ) based on factors such as candidate target cell signal strength, and frequency, or prioritizing the requirements of the application in use (at 16 ).
[0042] FIG. 5 lists the standardized QCI characteristics from 3GPP Standard 23.203 Section 6.1.7, which are used in this illustrative embodiment to define the handover criteria used in implementing the invention, according to the different requirements of different applications, for example maximum packet error loss rate, latency (packet delay) and priority.
[0043] For example, voice applications can withstand relatively high loss rates because there is considerable redundancy in the listening process. In particular, conversational voice (QCI 1) can withstand a higher loss rate (1%) than a streamed voice signal (QCI 7) (0.1%) because the listener provides feedback to the speaker on how clearly he can be understood. However, delay can be very disconcerting so the voice application has a lower tolerance to delay (100 ms instead of 300 ms). Real-time gaming (QCI 3) has an even lower tolerance of delay (50 ms), as users have to react to each other's actions.
[0044] Conversely, a signaling application (QCI 5), or a heavily compressed video application (QCI 4, 6, 8 or 9), is less tolerant to packet loss (1/1,000,000) but, because of buffering, can tolerate more delay (300 ms).
[0045] The base station or user terminal has access to data containing profile information about each handover base station candidate. This data may be stored in a data base local to the base station or in a shared database accessible to several base stations, or may be collected by the base station or user terminal when a handover is required.
[0046] FIG. 6 and FIG. 7 depict a profile containing a QCI handling priority score (E1, E2, E7) for each base station 1 , 2 , 3 , for each of three QCI classes, namely those classes for the Guaranteed Bit Rate and non-Guaranteed Bit Rate classes QCI 1, QCI 2 and QCI 7. Each base station also has a score for VoLTE support (A), Backhaul capacity (B), Guaranteed Bit Rate support (C) load information (D), and handling priority for the QCI class in question (E1, E2, E7) as depicted in FIGS. 4 and 5 .
[0047] The selection of the base station to be used is determined by applying weightings to the various scores A, B, C, D, E: these weightings depend on the required QCI class. For a factor (A, C) which is essential to support some applications, a binary label is applied depending on whether the base station in question supports that application. Thus, as shown in FIG. 6 , a handover of a session on which QCI class 1 (conversational voice) is in use, an illustrative weighting score is determined according to the formula:
[0000] Score (QCI1)= A *( B+D+E 1)
[0000] (note the binary label A multiplying the score by zero in this formula, thus giving any cell unable to provide VoLTE support a score of zero).
[0048] These calculations thereby identify Cell ID 3 as having the highest score for QCI 1. Thus, as shown in FIG. 8 (for QCI 1) the QCI value appropriate for the application in use is selected (at 60 ) and the target cells are then assessed to identify the optimum cell (at 61 ) to which connection can be made.
[0049] Similarly, as shown in FIG. 7 , a handover of a session on which QCI class 7 (streamed voice or video) is in use, an illustrative weighting score is determined according to the formula:
[0000] Score (QCI7)=4 B+D+E 7
[0050] These calculations thereby identify cell ID 2 as having the highest score for QCI 7.
[0051] The QCI value appropriate for the application in use can therefore be selected (at 60 ) and the target cells are then assessed to identify the optimum cell (at 61 ) to which connection can be made.
[0052] Referring again to FIG. 3 , the selection of the target cell (at 16 ) may determine that the currently serving cell is the optimum one for the application in use. This may be, for example, because no other cell in the vicinity having a better signal quality than the currently serving cell can support the application being run, or because a handover would have to be performed by “release with redirection” rather than seamlessly, and the application has a low latency threshold (at 98 , FIG. 2 ). In such a case, the selection at 16 determines that no handover should take place (at 17 ). The serving base station may then either drop the call, or may continue to operate the session, requesting further measurements (at 18 ) to monitor the continuing signal quality of the bearer link supporting the session.
[0053] The process may be initiated by any of several trigger events. If a user-connected cell, engaged on an application session that requires high QoS (i.e. low latency and jitter—e.g. VoLTE) becomes overloaded, the base station makes a decision to try to hand some of the user terminals over to a different radio access technology and/or frequency. The decision as to which devices should be handed over depends both on application requirements (application-type/bearer) and capabilities of the target cell (e.g. RAT, congestion level).
[0054] In an alternative scenario, in which handover is based on the serving cell's signal strength): when the signal strength of the serving cell becomes weak, the base station makes a decision as to which target radio access technology and frequency a handover should be performed. This is again based on the application requirements (application-type/bearer) and the capabilities of the target cell (e.g. RAT, congestion level)
[0055] The outcome could be that the operator decides to which target cell (RAT/frequency) handover should be made to ensure that quality of experience can be maintained. For example, it may be preferable to drop a VoLTE call than carrying on with severely degraded quality.
[0056] In a further scenario, a cellular to wifi handover decision is made by the user equipment based on data stored in the user equipment. The user terminal is initially connected to a first cell and engaged on an application session that requires high QoS (i.e. low latency and jitter—e.g. VoLTE). The terminal determines that a handover to WiFi may be desirable, and the handover decision is made based on the application(s) that are currently being used on the device.
[0057] In a yet further scenario, depicted in FIG. 9 , the handover process is triggered by the initiation of an application with a high QCI priority application (at 93 ). The handset may initiate the handover process by transmitting a notification 73 , indicative of the application required, to the currently-serving base station. This base station then initiates the base station selection and handover processes, prior to the data session being initiated. The processing to select the new handset is otherwise the same as for a network-initiated handover.
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A cellular telephone handover process, mediated by a mobile terminal or a base station, is controlled in accordance with Quality of service Control Indicators (QCIs) such that the base station to which handover is made (if any) is selected according to parameters which relate to the capability of each base station to handle the session or sessions currently is use. Handover may also be initiated if the user initiates an application not supported by the base station currently in use. If the session is running an application with a low latency threshold (e.g., conversational voice call), and a handover could only be achieved by interrupting the session by a “release with redirection” process, the handover is not proceeded with.
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APPLICATION DATA
[0001] This claims benefit to European Patent Application no. EP 04 020 125.3 filed Aug. 25, 2004.
FIELD OF INVENTION
[0002] The present invention relates to new dihydropteridinones of general formula (I)
wherein the groups L, R 1 , R 2 , R 3 , R 4 and R 5 have the meanings given in the claims and specification, the isomers thereof, processes for preparing these dihydropteridinones and their use as pharmaceutical compositions.
BACKGROUND TO THE INVENTION
[0003] Pteridinone derivatives are known from the prior art as active substances with an antiproliferative activity. WO 01/019825 and WO 03/020722 describe the use of pteridinone derivatives for the treatment of tumoral diseases.
[0004] Tumour cells wholly or partly elude regulation and control by the body and are characterised by uncontrolled growth. This is based on the one hand on the loss of control proteins, such as e.g. Rb, p16, p21 and p53 and also on the activation of so-called accelerators of the cell cycle, the cyclin-dependent kinases (CDK's). In addition, the protein kinase Aurora B has been described as having an essential function during entry into mitosis. Aurora B phosphorylates histone H3 at Ser10 and thus initiates chromosome condensation (Hsu et al. 2000, Cell 102:279-91). A specific cell cycle arrest in the G2/M phase may however also be triggered e.g. by the inhibition of specific phosphatases such as e.g. Cdc25C (Russell and Nurse 1986, Cell 45:145-53). Yeasts with a defective Cdc25 gene arrest in the G2 phase, while overexpression of Cdc25 leads to premature entry into the mitosis phase (Russell and Nurse 1987, Cell 49:559-67). Moreover, an arrest in the G2/M phase may also be triggered by the inhibition of certain motor proteins, the so-called kinesins such as e.g. Eg5 (Mayer et al. 1999, Science 286:971-4), or by agents which stabilise or destabilise microtubules (e.g. colchicin, taxol, etoposide, vinblastin and vincristine) (Schiff and Horwitz 1980, Proc Natl Acad Sci USA 77:1561-5).
[0005] In addition to the cyclin-dependent and Aurora kinases the so-called polo-like kinases, a small family of serine/threonine kinases, play an important part in the regulation of the eukaryotic cell cycle. Hitherto, the polo-like kinases PLK-1, PLK-2, PLK-3 and PLK-4 have been described in the literature. PLK-1 in particular has been shown to play a central part in the regulation of the mitosis phase. PLK-1 is responsible for the maturation of the centrosomes, for the activation of phosphatase Cdc25C, and for the activation of the Anaphase Promoting Complex (Glover et al. 1998, Genes Dev. 12:3777-87; Qian et al. 2001, Mol Biol Cell. 12:1791-9). The injection of PLK-1 antibodies leads to a G2 arrest in untransformed cells, whereas tumour cells arrest in the mitosis phase (Lane and Nigg 1996, J Cell Biol. 135:1701-13). Overexpression of PLK-1 has been demonstrated for various types of tumour, such as non-small-cell lung cancer, plate epithelial carcinoma, breast and colorectal carcinoma (Wolf et al. 1997, Oncogene 14:543-549; Knecht et al. 1999, Cancer Res. 59:2794-2797; Wolf et al. 2000, Pathol. Res. Pract. 196:753-759; Takahashi et al. 2003, Cancer Sci. 94:148-52). Therefore, this category of proteins also constitutes an interesting approach to therapeutic intervention in proliferative diseases (Liu and Erikson 2003, Proc Natl Acad Sci USA 100:5789-5794).
[0006] The resistance of many types of tumours calls for the development of new pharmaceutical compositions for combating tumours.
[0007] The aim of the present invention is to provide new compounds having an antiproliferative activity.
DESCRIPTION OF THE INVENTION
[0008] The problem according to the invention is solved by the following compounds of formula (I).
[0009] Accordingly, the present invention relates to dihydropteridinones of general formula (I)
wherein
L denotes a single bond, or a bridging double-bonded group selected from among C 1 -C 6 -alkylene, C 2 -C 6 -alkenylene, C 2 -C 6 -alkynylene, C 3 -C 7 -cycloalkylene, C 1 -C 4 -alkylene-C 6 -C 10 -arylene-C 1 -C 4 -alkylene, C 1 -C 4 -alkylene-C 6 -C 10 -arylene, —O, —O—C 1 -C 6 -alkylene, —O—C 3 -C 6 -alkenylene, —O—C 3 -C 6 -alkynylene, —O—C 3 -C 7 -cycloalkylene, —O—C 1 -C 4 -alkylene-C 6 -C 10 -arylene-C 1 -C 4 -alkylene, —O—C 1 -C 4 -alkylene-C 6 -C 10 -arylene, —NR 7 — and —NR 7 —C 1 -C 6 -alkylene, —NR 7 —C 3 -C 6 -alkenylene, —NR 7 —C 3 -C 6 -alkynylene, —NR 7 —C 3 -C 7 -cycloalkylene, —NR 7 —C 1 -C 4 -alkylene-C 6 -C 10 -arylene-C 1 -C 4 -alkylene, —NR 7 —C 1 -C 4 -alkylene-C 6 -C 10 -arylene, which may optionally be substituted by one or more groups R 9 ; R 1 and R 2 , which may be identical or different, denote hydrogen, or a group selected from among C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl and C 2 -C 6 -alkynyl, which may optionally be mono- or polysubstituted by one or more groups R 9 , or R 1 and R 2 together denote C 2 -C 6 -alkylene, in which optionally one or two methylene groups may be replaced by one of the groups —O or —NR 7 , and which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 3 denotes hydrogen or a group selected from C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, C 3 -C 8 -cycloalkyl and C 6 -C 14 -aryl, which may optionally be mono- or polysubstituted by one or more groups R 9 ; or R 3 and R 2 or R 3 and R 1 together denote C 2 -C 6 -alkylene which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 4 denotes hydrogen, halogen, CN, OH, —NR 7 R 8 or a group selected from among C 1 -C 6 -alkyl, C 1 -C 6 -alkyloxy, C 2 -C 6 -alkenyl, C 2 -C 6 -alkenyloxy, C 2 -C 6 -alkynyl and C 2 -C 6 -alkynyloxy, which may optionally be mono- or polysubstituted by one or more groups R 10 ; R 5 denotes phenyl, which may optionally be mono- or polysubstituted by one or more groups R 11 , or R 5 phenyl which is monosubstituted by a group R 6 , or R 5 denotes C 1 -C 4 -alkyl which may optionally be mono- or polysubstituted by one or more groups R 9 , or R 6 denotes —NR 7 R 8 or a 5-10-membered heterocycloalkyl group which may contain one, two or three heteroatoms selected from among nitrogen, oxygen and sulphur, preferably nitrogen or oxygen, and which may optionally be mono- or polysubstituted by one or more of the groups R 12 ; R 7 and R 8 , which may be identical or different, denote hydrogen or C 1 -C 6 -alkyl, R 9 denotes halogen, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, CN, OH or CF 3 ; R 10 denotes halogen, OH, CN, ═O, C 1 -C 6 -alkyloxy, COOR 7 , NR 7 R 8 , CONR 7 R 8 , SO 2 R 7 , CHF 2 or CF 3 ; R 11 denotes halogen, OH, CN, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, COOR 7 , CONR 7 R 8 , SO 2 R 7 , CHF 2 , CF 3 , C 6 -C 10 -aryl or C 1 -C 6 -alkylene-C 6 -C 10 -aryl; R 12 denotes halogen, CF 3 , C 1 -C 6 -alkyl, C 1 -C 6 -alkylene-C 6 -C 10 -aryl, C 3 -C 8 -cycloalkyl or C 1 -C 6 -alkylene-C 3 -C 8 -cycloalkyl;
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0025] Preferred are compounds of general formula (I), wherein
L denotes a single bond, or a bridging double-bonded group selected from among C 1 -C 6 -alkylene, C 2 -C 6 -alkenylene, C 2 -C 6 -alkynylene, C 3 -C 7 -cycloalkylene, C 1 -C 4 -alkylene-C 6 -C 10 -arylene-C 1 -C 4 -alkylene, —O, —O—C 1 -C 4 -alkylene, —NR 7 - and —NR 7 -C 1 -C 4 -alkylene, which may optionally be substituted by one or more groups R 9 ; R 1 and R 2 , which may be identical or different, denote hydrogen, or a group selected from among C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl and C 2 -C 6 -alkynyl, which may optionally be mono- or polysubstituted by one or more groups R 9 , or R 1 and R 2 together denote C 2 -C 6 -alkylene, in which optionally one or two methylene groups may be replaced by one of the groups —O or —NR 7 , and which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 3 denotes hydrogen or a group selected from C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, C 3 -C 8 -cycloalkyl and C 6 -C 14 -aryl, which may optionally be mono- or polysubstituted by one or more groups R 9 ; or R 3 and R 2 or R 3 and R 1 together denote C 2 -C 6 -alkylene which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 4 denotes hydrogen, halogen, CN, OH, —NR 7 R 8 or a group selected from among C 1 -C 6 -alkyl, C 1 -C 6 -alkyloxy, C 2 -C 6 -alkenyl, C 2 -C 6 -alkenyloxy, C 2 -C 6 -alkynyl and C 2 -C 6 -alkynyloxy, which may optionally be mono- or polysubstituted by one or more groups R 10 ; R 5 denotes phenyl, which may optionally be mono- or polysubstituted by one or more groups R 11 , or R 5 denotes phenyl which is monosubstituted by a group R 6 , or R 5 denotes C 1 -C 4 -alkyl which may optionally be mono- or polysubstituted by one or more groups R 9 , or R 6 denotes a 5-10-membered heterocycloalkyl group which may contain one, two or three heteroatoms selected from among nitrogen, oxygen and sulphur, preferably nitrogen or oxygen, and which may optionally be mono- or polysubstituted by one or more of the groups R 12 ; R 7 and R 8 , which may be identical or different, denote hydrogen or C 1 -C 6 -alkyl, R 9 denotes halogen, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, CN, OH or CF 3 ; R 10 denotes halogen, OH, CN, ═O, C 1 -C 6 -alkyloxy, COOR 7 , CONR 7 R 8 , SO 2 R 7 , CHF 2 or CF 3 ; R 11 denotes halogen, OH, CN, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, COOR 7 , CONR 7 R 8 , SO 2 R 7 , CHF 2 , CF 3 , C 6 -C 10 -aryl or C 1 -C 6 -alkylene-C 6 -C 10 -aryl; R 12 denotes halogen, CF 3 , C 1 -C 6 -alkyl, C 1 -C 6 -alkylene-C 6 -C 10 -aryl, C 3 -C 8 -cycloalkyl or C 1 -C 6 -alkylene-C 3 -C 8 -cycloalkyl;
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0041] Also preferred are compounds of general formula (I), wherein
L denotes a single bond, —O, —O—C 1 -C 3 -alkylene, —NR 7 , —NR 7 —C 1 -C 3 -alkylene or C 1 -C 4 -alkylene, which may optionally be substituted by one or more groups R 9 ; R 1 and R 2 , which may be identical or different, denote hydrogen, or a group selected from among C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl and C 2 -C 4 -alkynyl, which may optionally be mono- or polysubstituted by one or more groups R 9 , or R 1 and R 2 together denote C 2 -C 4 -alkylene which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 3 denotes hydrogen or a group selected from C 1 -C 6 -alkyl, C 3 -C 7 -cycloalkyl and C 6 -C 10 -aryl, which may optionally be mono- or polysubstituted by one or more groups R 9 ; or R 3 and R 2 or R 3 and R 1 together denote C 2 -C 4 -alkylene which may optionally be mono- or polysubstituted by one or more groups R 9 ; R 4 denotes hydrogen, fluorine, chlorine, bromine, —NR 7 R 8 or a group selected from among C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, C 2 -C 4 -alkenyloxy and C 2 -C 4 -alkynyloxy, which may optionally be mono- or polysubstituted by one or more groups R 10 ; R 5 denotes phenyl which may optionally be mono- or disubstituted by one or more groups R 11 , or R 5 denotes phenyl which is monosubstituted by a group R 6 , or R 5 denotes a group selected from among methyl, ethyl, propyl and butyl which may optionally be mono- or disubstituted by one or more groups R 9 ; R 6 denotes a heterocycloalkyl selected from among piperidinyl, piperazinyl, pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl and morpholinyl which may optionally be mono- or polysubstituted by one or more of the groups R 12 ; R 7 and R 8 , which may be identical or different, denote hydrogen or C 1 -C 4 -alkyl, R 9 denotes halogen, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, CN, OH or CF 3 ; R 10 denotes halogen, OH, ═O, C 1 -C 4 -alkyloxy or CF 3 ; R 11 denotes halogen, OH, CN, C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, COOR 7 , CF 3 , or C 1 -C 4 -alkylene-phenyl; R 12 denotes C 1 -C 4 -alkyl, C 1 -C 4 -alkylene-phenyl, C 3 -C 6 -cycloalkyl or C 1 -C 4 -alkylene-C 3 -C 6 -cycloalkyl;
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0057] Also preferred are compounds of general formula (I),
wherein L denotes a single bond, C 1 -C 4 -alkylene, —O, —O—C 1 -C 3 -alkylene, —NH or —NH—C 1 -C 3 -alkylene; R 1 and R 2 , which may be identical or different, denote hydrogen, or a group selected from among C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl and C 2 -C 4 -alkynyl, which may optionally be mono- or disubstituted by a group selected from among fluorine, chlorine, OH and CF 3 ; or R 3 denotes hydrogen or a group selected from C 1 -C 6 -alkyl, C 3 -C 7 -cycloalkyl and C 6 -C 10 -aryl, which may optionally be mono- or disubstituted by a group selected from among fluorine, chlorine, methyl, ethyl, OH, methyloxy, ethyloxy and CF 3 ; R 4 denotes hydrogen, fluorine, chlorine, bromine, —NR 7 R 8 or a group selected from among C 1 -C 4 -alkyl, C 1 -C 4 -alkyloxy, C 2 -C 4 -alkenyloxy and C 2 -C 4 -alkynyloxy, which may optionally be mono- or disubstituted by a group selected from among fluorine, chlorine, OH, methoxy, ethoxy and CF 3 ; R 5 denotes phenyl, which may optionally be mono- or disubstituted by a group selected from among methyl, ethyl, OH, fluorine, chlorine, CF 3 , COOH, COOmethyl or COOethyl, or R 5 denotes phenyl which is monosubstituted by a heterocycloalkyl selected from among piperidinyl, piperazinyl, pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl and morpholinyl, which may be mono- or disubstituted by methyl, ethyl, benzyl, phenethyl, cyclopropyl or cyclopropylmethyl, or R 5 denotes a group selected from among methyl, ethyl, propyl and butyl which may optionally be mono- or disubstituted by one or more groups selected from among fluorine, chlorine, OH and CF 3 ;
R 7 and R 8 , which may be identical or different, denote hydrogen, methyl or ethyl, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0066] Also preferred are compounds of general formula (I),
wherein L denotes a single bond, —CH 2 , —CH 2 —CH 2 , —O, —O—CH 2 , —O—CH 2 —CH 2 , —NH, —NH—CH 2 or —NH—CH 2 —CH 2 —; R 1 and R 2 , which may be identical or different, denote hydrogen or a group selected from among methyl, ethyl, propyl, butyl, allyl and propargyl, which may optionally be mono- or disubstituted by a group selected from among fluorine, chlorine and CF 3 ; R 3 denotes hydrogen or a group selected from among methyl, ethyl, propyl, butyl, pentyl, cyclopropyl, cyclopentyl, cyclohexyl and phenyl, which may optionally be mono- or disubstituted by a group selected from among fluorine, chlorine, methyl, ethyl, methyloxy, ethyloxy and CF 3 ; R 4 denotes hydrogen, methyl, ethyl, propyl, methyloxy, ethyloxy or propyloxy; R 5 denotes phenyl, which may optionally be mono- or disubstituted by a group selected from among methyl, OH, fluorine, CF 3 , COOH, COOmethyl or COOethyl, or R 5 denotes phenyl which is monosubstituted by a heterocycloalkyl selected from among piperidinyl, piperazinyl, pyrrolidinyl and morpholinyl, which may be mono- or disubstituted by methyl, ethyl, benzyl, phenethyl, cyclopropyl or cyclopropylmethyl; R 5 denotes a group selected from among methyl, ethyl, propyl and butyl which may optionally be mono- or disubstituted by one or more groups selected from the group fluorine, chlorine and CF 3 ;
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0075] Of particular importance according to the invention are compounds of general formula (I) , wherein
L denotes a single bond, or a bridging double-bonded group selected from among —CH 2 , —CH 2 —CH 2 , —O, —O—CH 2 , —O—CH 2 —CH 2 , —NH, —NH—CH 2 or —NH—CH 2 —CH 2 , preferably a single bond or a group selected from —CH 2 , —CH 2 —CH 2 , —O, —O—CH 2 , —NH or —NH—CH 2 ,
and the groups R 1 , R 2 , R 3 , R 4 and R 5 and R 9 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0077] In asymmetrical groups L, the above-mentioned bridging double-bonded groups may be linked in one of two different orientations. According to the invention preferred compounds of formula (I) are those wherein, in the case of an asymmetrical group L, the heteroatom of the group L is linked to the carbonyl function of the compound of formula (I).
[0078] Also of particular importance according to the invention are compounds of general formula (I), wherein
L denotes —NH, —NH—CH 2 or —NH—CH 2 —CH 2 —, R 4 is hydrogen
and the groups R 1 , R 2 , R 3 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0081] Also of particular importance according to the invention are compounds of general formula (I), wherein L denotes —O, —O—CH 2 or —O—CH 2 —CH 2 — and the groups R 1 , R 2 , R 3 , R 4 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0082] Of particular importance according to the invention are compounds of general formula (I), wherein R 1 denotes hydrogen, methyl, ethyl, allyl or propargyl, preferably hydrogen or methyl, particularly preferably hydrogen and the groups L, R 2 , R 3 , R 4 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0083] Of particular importance according to the invention are compounds of general formula (I), wherein R 2 denotes hydrogen, methyl, ethyl, allyl or propargyl, preferably hydrogen, methyl or ethyl, particularly preferably methyl or ethyl, and the groups L, R 1 , R 3 , R 4 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0084] Of particular importance according to the invention are compounds of general formula (I), wherein
R 3 denotes methyl, ethyl, propyl, butyl, pentyl, cyclopropyl, cyclopentyl or cyclohexyl, preferably propyl, butyl, pentyl, cyclopentyl or cyclohexyl, particularly preferably propyl, butyl, pentyl, cyclopentyl or cyclohexyl, while propyl, pentyl, cyclopentyl or cyclohexyl, particularly cyclypentyl and cyclohexyl are of particular importance,
and the groups L, R 1 , R 2 , R 4 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0086] Of particular importance according to the invention are compounds of general formula (I) wherein R 3 denotes phenyl, which may optionally be mono- or disubstituted, preferably monosubstituted, by fluorine, chlorine, methyl, ethyl, methyloxy, ethyloxy and CF 3 , preferably phenyl, which may optionally be mono- or disubstituted, preferably monosubstituted, by fluorine, methyl or methyloxy, and the groups L, R 1 , R 2 , R 4 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0087] Of particular importance according to the invention are compounds of general formula (I), wherein
R 4 denotes hydrogen, methyl, ethyl, methyloxy or ethyloxy, preferably hydrogen, methyl or methyloxy, particularly preferably hydrogen or methyloxy,
and the groups L, R 1 , R 2 , R 3 and R 5 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0089] Of particular importance according to the invention are compounds of general formula (I), wherein
R 5 denotes phenyl, which may optionally be mono- or disubstituted by a group selected from among methyl, OH, fluorine, CF 3 , COOH, COOmethyl or COOethyl, preferably selected from among fluorine, CF 3 , COOH, COOmethyl or COOethyl,
and the groups L, R 1 , R 2 , R 3 and R 4 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0091] Of particular importance according to the invention are compounds of general formula (I), wherein
R 5 denotes phenyl which is monosubstituted by a heterocycloalkyl selected from among piperidinyl, piperazinyl, pyrrolidinyl and morpholinyl, which may be mono- or disubstituted by methyl, ethyl, benzyl, phenethyl, cyclopropyl or cyclopropylmethyl
and the groups L, R 1 , R 2 , R 3 and R 4 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0093] Of particular importance according to the invention are compounds of general formula (I), wherein
R 5 denotes phenyl which is monosubstituted by a heterocycloalkyl selected from among piperidinyl, piperazinyl and morpholinyl, which may be mono- or disubstituted by methyl, ethyl, benzyl or cyclopropylmethyl, preferably methyl or ethyl,
and the groups L, R 1 , R 2 , R 3 and R 4 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0095] Of particular importance according to the invention are compounds of general formula (I), wherein
R 5 denotes a group selected from among methyl, ethyl, propyl and butyl which may optionally be mono- or disubstituted by one or more groups selected from the group fluorine, chlorine and CF 3 ,
and the groups L, R 1 , R 2 , R 3 and R 4 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0097] Of particular importance according to the invention are compounds of general formula (I), wherein R 5 denotes a group selected from among methyl, ethyl, propyl and butyl, and the groups L, R 1 , R 2 , R 3 and R 4 may have one of the meanings given above or hereinafter, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0098] The term alkyl groups, including alkyl groups which are a part of other groups, denotes branched and unbranched alkyl groups with 1 to 8 carbon atoms, preferably 1 -6, most preferably 1-4 carbon atoms. Examples include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl. Unless otherwise stated, the abovementioned terms propyl, butyl, pentyl, hexyl, heptyl and octyl include all the possible isomeric forms. For example, the term propyl includes the two isomeric groups n-propyl and iso-propyl, the term butyl includes n-butyl, iso-butyl, sec.butyl and tert.-butyl, the term pentyl includes iso-pentyl, neopentyl, etc.
[0099] In the abovementioned alkyl groups, unless stated to the contrary, one or more hydrogen atoms may optionally be replaced by other groups. For example these alkyl groups may be substituted fluorine. All the hydrogen atoms of the alkyl group may optionally also be replaced.
[0100] By alkyloxy groups, optionally also known as alkoxy groups or —O-alkyl groups, are meant the above-mentioned alkyl groups which are linked by an oxygen bridge. Examples include: methyloxy, ethyloxy, propyloxy, butyloxy, pentyloxy, hexyloxy, heptyloxy and octyloxy, which are optionally also known as methoxy, ethoxy, propoxy etc.
[0101] By alkylene bridges or alkylene groups are meant, unless stated otherwise, branched and unbranched alkyl groups with 1 to 6 carbon atoms, for example methylene, ethylene, propylene, isopropylene, n-butylene, iso-butyl, sec.butyl and tert.-butyl etc. bridges. Particularly preferred are methylene, ethylene, propylene and butylene bridges. In the above-mentioned alkylene bridges, unless stated otherwise or additionally defined, 1 to 2 C atoms may optionally be replaced by one or more heteroatoms selected from among oxygen, nitrogen or sulphur.
[0102] By alkenyl groups (including those which are a part of other groups) are meant branched and unbranched alkylene groups with 2 to 8 carbon atoms, preferably 2-6 carbon atoms, particularly preferably 2-3 carbon atoms, provided that they have at least one double bond. Examples include: ethenyl, propenyl, butenyl, pentenyl, etc. Unless otherwise specified, the terms propenyl, butenyl etc. used above encompass all the possible isomeric forms. For example the term butenyl includes 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl and 1-ethyl-1-ethenyl.
[0103] In the above-mentioned alkenyl groups, unless otherwise stated, one or more hydrogen atoms may optionally be replaced by other groups. For example these alkyl groups may be substituted by halogen atoms in the form of fluorine. All the hydrogen atoms of the alkenyl group may optionally also be replaced.
[0104] Examples of alkenyloxy groups, optionally also known as alkenoxy groups or —O-alkenyl groups, are the above-mentioned alkenyl groups which are linked by an oxygen bridge. Examples include: ethylenoxy, propylenoxy, butylenoxy.
[0105] Examples of alkenylene groups (including those which are part of other groups) include branched and unbranched, bridging alkylene groups with 2 to 6 carbon atoms, preferably 2-4 carbon atoms, particularly preferably 2-3 carbon atoms, provided that they have at least one double bond. Examples include: ethenylene, propenylene etc. Unless stated otherwise, the terms propenylene, butenylene etc. used above include all the possible isomeric forms.
[0106] Examples of alkynyl groups (including those which are part of other groups) are branched and unbranched alkynyl groups with 2 to 8 carbon atoms, provided that they have at least one triple bond, for example ethynyl, propargyl, butynyl, pentynyl, hexynyl etc., preferably ethynyl or propynyl. In the above-mentioned alkynyl groups, unless otherwise stated, one or more hydrogen atoms may optionally be replaced by other groups. For example these alkynyl groups may be substituted by fluorine. All the hydrogen atoms of the alkynyl group may optionally also be replaced.
[0107] Examples of alkynyloxy groups, optionally also known as alkynoxy groups or —O-alkynyl groups, are the above-mentioned alkynyl groups which are linked by an oxygen bridge.
[0108] Examples of alkynylene groups (including those which are part of other groups) are branched and unbranched, bridging alkynyl groups with 2 to 6 carbon atoms, provided that they have at least one triple bond, for example ethynylene, propargylene etc. In the above-mentioned alkynylene groups, unless otherwise stated, one or more hydrogen atoms may optionally be replaced by other groups. Unless stated otherwise, the terms propargylene etc. used above include all the possible isomeric forms.
[0109] The term aryl denotes an aromatic ring system with 6 to 14 carbon atoms, preferably 6 or 10 carbon atoms, preferably phenyl or naphthyl, particularly preferably phenyl.
[0110] Examples of cycloalkyl groups are cycloalkyl groups with 3-8 carbon atoms, for example cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, preferably cyclopropyl, cyclopentyl or cyclohexyl. Apart from cyclopropyl and cyclobutyl, the above-mentioned cycloalkyl groups may optionally also be partially unsaturated, i.e. they may contain at least one double bond such as for example cyclohexene. The term cycloalkylene group denotes bridging, double-bonded cycloalkyl groups.
[0111] “═O” denotes an oxygen atom linked by a double bond.
[0112] Examples of 5-10-membered heterocycloalkyl groups which may contain one, two or three heteroatoms selected from among nitrogen, oxygen and sulphur, preferably nitrogen or oxygen, include, unless stated otherwise in the definitions, for example tetrahydrofuranyl, tetrahydrofuranonyl, γ-butyrolactonyl, α-pyranyl, γ-pyranyl, dioxolanyl, tetrahydropyranyl, dioxanyl, dihydrothiophenyl, thiolanyl, dithiolanyl, pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, diazepanyl, oxazinyl, tetrahydrooxazinyl, pyrazolidinyl, preferably morpholinyl, pyrrolidinyl, piperidinyl and piperazinyl.
[0113] Halogen generally denotes fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, particularly preferably fluorine or chlorine.
[0114] The compounds according to the invention may be present in the form of the individual optical isomers, mixtures of the individual enantiomers, diastereomers or racemates, in the form of the tautomers and in the form of the free bases or the corresponding acid addition salts with pharmacologically acceptable acids. By acid addition salts with pharmacologically acceptable acids are meant, for example, the salts selected from among the hydrochloride, hydrobromide, hydroiodide, hydrosulphate, hydrophosphate, hydromethanesulphonate, hydronitrate, hydromaleate, hydroacetate, hydrobenzoate, hydrocitrate, hydrofumarate, hydrotartrate, hydrooxalate, hydrosuccinate, hydrobenzoate and hydro-p-toluenesulphonate, preferably the hydrochloride, hydrobromide, hydrosulphate, hydrophosphate, hydrofumarate and hydromethanesulphonate.
[0115] Of the above-mentioned acid addition salts the salts of hydrochloric acid, methanesulphonic acid, benzoic acid and acetic acid are particularly preferred according to the invention.
[0116] Of the enantiomers and diastereomeric compounds of general formula (I) which may optionally exist, the optical isomers which have the R configuration at the carbon centre carrying the two groups R 1 and R 2 are preferred according to the invention
[0117] The group R 4 , if it is not hydrogen, may be linked in the ortho or meta position in relation to the NH group linked to the pteridinone structure in the compounds of general formula (I). Particularly preferred are those compounds of general formula (I) wherein R 4 is in the ortho configuration relative to the above-mentioned NH group. These preferred compounds are characterised by general formula (I′)
wherein the groups L, R 1 , R 2 , R 3 , R 4 and R 5 may have the above-mentioned meanings, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
[0118] The compounds according to the invention may be prepared by synthesis method A described hereinafter, the substituents of general formulae (A1) to (A9) being defined as hereinbefore. This method is to be understood as illustrating the invention without restricting it to the content thereof.
[0000] Method A
[0000] Step 1A
[0119] A compound of formula (A1) is reacted with a compound of formula (A2) to produce a compound of formula (A3) (Diagram 1A). This reaction may be carried out according to WO 0043369 or WO 0043372. Compound (A1) is commercially obtainable, for example from City Chemical LLC, 139 Allings Crossing Road, West Haven, Conn., 06516, USA. Compound (A2) may be prepared by methods described in the literature (a) F. Effenberger, U. Burkhart, J. Willfahrt Liebigs Ann. Chem. 1986, 314-333. b) T. Fukuyama, C.-K. Jow, M. Cheung, Tetrahedron Lett. 1995, 36, 6373-6374. c) R. K. Olsen, J. Org. Chem. 1970, 35, 1912-1915. d) F. E. Dutton, B. H. Byung Tetrahedron Lett. 1998, 30, 5313-5316. e) J. M. Ranajuhi, M. M. Joullie Synth. Commun. 1996, 26, 1379-1384.
[0120] In Step 1A, 1 equivalent of the compound (A1) and 1 to 1.5 equivalents, preferably 1.1 equivalents of a base, preferably potassium carbonate, potassium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate or calcium carbonate, particularly preferably potassium carbonate, are stirred in a diluent, optionally mixed with water, for example acetone, tetrahydrofuran, diethyl ether, cyclohexane, methylcyclohexane, petroleum ether or dioxane, preferably cyclohexane or diethyl ether.
[0121] At a temperature of 0 to 15° C., preferably 5 to 10° C., 1 equivalent of an amino acid of formula (A2) dissolved in an organic solvent, for example acetone, tetrahydrofuran, diethyl ether, cyclohexane or dioxane, is added dropwise. The reaction mixture is heated to a temperature of 18° C. to 30° C., preferably about 22° C., with stirring and then stirred for a further 10 to 24 hours, preferably about 12 hours. Then the diluent is distilled off, the residue is combined with water and the mixture is extracted two to three times with an organic solvent, for example, diethyl ether or ethyl acetate, preferably ethyl acetate. The combined organic extracts are dried and the solvent is distilled off. The residue (compound A3) may be used in Step 2 without any prior purification.
[0000] Step 2A
[0122] The compound (A3) obtained in Step 1A is reduced at the nitro group and cyclised to form the compound of formula (A4) (Diagram 2A).
In Step 2A 1 equivalent of the nitro compound (A3) is dissolved in an acid, preferably glacial acetic acid, formic acid or aqueous hydrochloric acid, preferably glacial acetic acid, and heated to 50 to 70° C., preferably about 60° C. Then a reducing agent, for example zinc, tin or iron, preferably iron powder, is added until the exothermic reaction has ended and the mixture is stirred for 0.2 to 2 hours, preferably 0.5 hours, at 100 to 125° C., preferably at about 115° C. After cooling to ambient temperature the iron salt is filtered off and the solvent is distilled off. The residue is taken up in a solvent or mixture of solvents, for example ethyl acetate or dichloromethane/methanol 9/1 and semisaturated NaCl solution and filtered through kieselguhr for example. The organic phase is dried and evaporated down. The residue (compound (A4)) may be purified by chromatography or by crystallisation or used as the crude product in Step 3A of the synthesis.
Step 3A
[0123] The compound (A4) obtained in Step 2A may be reacted by electrophilic substitution according to Diagram 3A to form the compound of formula (A5).
[0124] In Step 3A 1 equivalent of the amide of formula (A4) is dissolved in an organic solvent, for example dimethylformamide or dimethylacetamide, preferably dimethylacetamide, and cooled to about −5 to 5° C., preferably 0° C.
[0125] Then 0.9 to 1.3 equivalents sodium hydride and 0.9 to 1.3 equivalents of a methylating reagent, for example methyliodide, are added. The reaction mixture is stirred for 0.1-3 hours, preferably about 1 hour, at about 0 to 10° C., preferably at about 5° C., and may optionally be left to stand for a further 12 hours at this temperature range. The reaction mixture is poured onto ice water and the precipitate is isolated. The residue (compound (A5)) may be purified by chromatography, preferably on silica gel, or by crystallisation or used as the crude product in Step 4A of the synthesis.
[0000] Step 4A
[0126] The amination of the compound (A5) obtained in Step 3A to form the compound of formula (I) (Diagram 4A) may be carried out according to the methods of variants 4.1 A known from the literature from (a) M. P. V. Boarland, J. F. W. McOmie J Chem. Soc. 1951, 1218-1221 or (b) F. H. S. Curd, F. C. Rose J. Chem. Soc. 1946, 343-348, or 4.2A from (a) Banks J. Am. Chem. Soc. 1944, 66, 1131, (b) Ghosh and Dolly J. Indian Chem. Soc. 1981, 58, 512-513 or (c) N. P. Reddy and M. Tanaka Tetrahedron Lett. 1997, 38, 4807-4810.
[0127] For example in variant 4.1 A, 1 equivalent of the compound (A5) and 1 to 3 equivalents, preferably about 1 equivalent of the compound (A6) may be heated without a solvent or with an organic solvent such as for example sulpholane, dimethylformamide, dimethylacetamide, toluene, N-methylpyrrolidone, dimethylsulphoxide, or dioxane, preferably sulpholane over 0.1 to 4 hours, preferably 1 hour, at 100 to 220° C., preferably at about 160° C. After cooling the product (A9) is crystallised by the addition of org. solvents or mixtures of solvents, e.g. diethyl ether/methanol, ethyl acetate, methylene chloride, or diethyl ether, preferably diethyl ether/methanol 9/1, or purified by chromatography.
[0128] For example in variant 4.2A, 1 equivalent of the compound (A1) and 1 to 3 equivalents of the compound (A6) are refluxed with acid, for example 1-10 equivalents of 10-38% hydrochloric acid and/or an alcohol, for example ethanol, propanol, dioxane, butanol, preferably ethanol for 1 to 48 hours, preferably about 5 hours, with stirring. The precipitated product of formula (I) is filtered off and optionally washed with water, dried and crystallised from a suitable org. solvent.
[0129] As can be seen from Diagram 4A, the compounds of formula (A5) are of central importance for the synthesis of the compounds of general formula (I) according to the invention. Accordingly, the present invention also relates to intermediate compounds of general formula (A5)
wherein the groups R 1 , R 2 and R 3 may have the above-mentioned meanings, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the acid addition salts, solvates and/or hydrates thereof.
[0130] The products of formula (A7) are obtained analogously to the processes described and after further reaction are converted into the products of formula (I) (see Step 5A).
The group PG, as shown in the above diagram at compounds (A7a), may be one of the amino protecting groups known in the art. Suitable methods of cleaving the group PG and hence converting the compounds into the compounds of formula (A8) are known in the art (cf. T. W. Greene, “Protective Groups in Organic Synthesis”, 2nd Edition).
[0131] The compounds of formulae (A9a), (A9b) and (A9c) shown in Diagram 5A are specific examples of the compounds of formula (I) according to the invention. In the compounds of formula (A9a) L does not represent a group L which is linked to the carbonyl carbon by an —NH or —O— bridge. Rather, these compounds are represented by formulae (A9b) and (A9c).
[0000] Step 5A
[0132] After the amination in Step 4A the products of formula (A9) may also be obtained by cleaving an acid- or base-labile group, for example, from compounds of type (A7) or by reduction of a nitro group to the amine (A8) and then reacting it to form amides (A9a), urethanes (A9b) or ureas (A9c) (cf. Diagram 5A).
[0000] Variant 5.1A:
[0133] For example, 1 equivalent of a compound (A7a) is combined with an acid-labile protective group, for example tert-butyloxycarbonyl with 1-50 equivalents of acid, preferably HCl or trifluoroacetic acid, in an organic solvent e.g. methylene chloride, ether, dioxane, tetrahydrofuran, preferably methylene chloride and stirred for 1 to 24 h at 20-100° C., preferably 20° C. The reaction mixture is separated for example on silica gel or obtained by suitable crystallisation.
[0000] Variant 5.2B:
[0134] For example 1 equivalent of a compound (A7b) is dissolved in a solvent e.g. methanol, ethanol, THF, ethyl acetate, water and combined with 0.001 to 0.1 equivalent Pd/C (10%) and hydrogenated with hydrogen for 1-24 h. After filtration of the catalyst the product (A8) is obtained and is optionally purified by silica gel chromatography or by suitable crystallisation.
[0000] Preparation of the Amides (A9a):
[0135] For example, 1 equivalent of the compound (A8) is dissolved with 1 equivalent of an activating reagent, e.g. O-benzotriazolyl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) and a base, for example about 1.5 equivalents, diisopropylethylamine (DIPEA) in an organic diluent, for example dichloromethane, tetrahydrofuran, dimethylformamide, N-methylpyrrolidone, dimethylacetamide, preferably dichloromethane or dimethylformamide. After the addition of 1 equivalent of the amine (A10) the reaction mixture is stirred for 0.1 to 24 hours, preferably about 2 hours at 20° C. to 100° C. The product of formula (A9a) is obtained for example by crystallisation or chromatographic purification.
[0000] Preparation of the Ureas (A9b):
[0136] The compounds A9b mentioned in Diagram 5A are compounds wherein L denotes an NH group. The processes described hereinafter may also be used if L represents not only NH but also —NH-alkylene, for example, as will be apparent to the skilled man.
[0000] Variant A:
[0137] 1 equivalent of amine (A8) is dissolved in an organic solvent, for example dichloromethane, THF, dimethylformamide, and a base, for example pyridine, triethylamine, disopropylethylamine, and combined with 1-2 equivalents, preferably 1 equivalent, of 4-nitrophenyl chloroformate. After 1-24 h, preferably 2-5 h, 1 equivalent H 2 N-L n -R 5 , dissolved in an organic solvent, is added and the mixture is stirred for 4-24 h at 20° C. The product of formula (A9b) is obtained for example by crystallisation or chromatographic purification.
[0000] Variant B:
[0138] 1 equivalent of the amine (A8) is dissolved together with 1-3 equivalents of an isocyanate in an organic solvent such as dimethylformamide, THF, dimethylacetamide and stirred for 1-24 h at 40-70° C.
[0139] After the solvent has been eliminated the product (A9b) is obtained for example by crystallisation or chromatographic purification.
[0000] Preparation of the Urethanes (A9c):
[0140] The compounds A9c shown in Diagram 5A are compounds wherein L denotes an —O— group. The processes described hereinafter may also be used if L represents not only O but also —O-alkylene, for example, as will be apparent to the skilled man.
[0141] 1 equivalent of the amine (A7) is dissolved in an organic solvent, such as dichloromethane, dimethylformamide, THF and combined with 1-3 equivalents of base, for example diisopropylethylamine, triethylamine. Subsequently 1-3 equivalents of a chloroformate are added and the mixture is stirred for 1-24 h at 20-60° C. After the solvent has been eliminated the product (A9c) is obtained for example by crystallisation or chromatographic purification.
[0142] As can be seen from Diagram 5A, the compounds of formula (A8) are of central importance in the synthesis of the compounds of general formula (I) according to the invention. Accordingly, the present invention also relates to intermediate compounds of general formula (A8)
wherein the groups R 1 , R 2 , R 3 and R 4 may have the above-mentioned meanings, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the acid addition salts, solvates and/or hydrates thereof.
[0143] Examples of acid addition salts which may be used particularly include those salts mentioned hereinbefore for the compounds of formula (I) as being pharmacologically acceptable acid addition salts.
[0144] As can be seen from Diagram 5A, the compounds of formula (A7a) are also of major importance in the synthesis of the compounds of general formula (I) according to the invention. Accordingly, the present invention also relates to intermediate compounds of general formula (A7a)
wherein the groups R 1 , R 2 , R 3 and R 4 may have the meanings given above and wherein PG denotes an amino protecting group, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the acid addition salts, solvates and/or hydrates thereof.
[0145] Preferred are compounds of general formula (A7a), wherein
PG is selected from among tert-butyloxycarbonyl, acetyl, trifluoromethyl, 9-fluoroenylmethyloxycarbonyl, allyloxycarbonyl and benzyloxycarbonyl, preferably tert-butyloxycarbonyl, acetyl and trifluoromethyl,
optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the acid addition salts, solvates and/or hydrates thereof.
[0147] As can be seen from Diagram 5A, the compounds of formula (A7b) are also of major importance in the synthesis of the compounds of general formula (I) according to the invention. Accordingly, the present invention also relates to intermediate compounds of general formula (A7b)
wherein the groups R 1 , R 2 , R 3 and R 4 may have the meanings given above, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the acid addition salts, solvates and/or hydrates thereof.
[0148] The preparation of a reactant used to synthesise specific intermediates of general formula (A8), the intermediate compounds Z1-Z12, is described below.
[0149] Preparation of tert-butyl 4-amino-3-methoxy-phenyl-carbamate:
[0150] 15 g of 4-nitro-3-methoxybenzoic acid was dissolved in 35 g tert-butanol, 16 mL disopropylethylamine and 15 mL toluene, then combined with 17.5 mL diphenylphosphorylazide and refluxed for 7 h. The mixture was then evaporated down and combined with 500 mL ethyl acetate and extracted with 3×200 mL water. The org. phase was dried and the reaction mixture was separated by silica gel chromatography (petroleum ether:ethyl acetate 3:1), and suitable fractions were combined. Yield: 16.1 g of a compound B1 (pale yellow crystals)
[0151] 16 g of the compound B1 was dissolved in 400 mL ethanol and reacted with 6 g 10% Pd/C with hydrogen at 20° C. The reaction solution was evaporated down and the solid was triturated with diethyl ether.
[0152] Yield: 10.5 g tert-butyl 4-amino-3-methoxy-phenyl-carbamate (colourless crystals)
[0153] In order to synthesise Example 5 first of all an intermediate compound Z1 is prepared as described below.
[0154] 100 g trifluoromethanesulphonic anhydride was placed in 50 mL dichloromethane and a mixture of 39 mL ethyl L-lactate and 28 mL pyridine in 200 mL dichloromethane was added dropwise in 60 min while cooling with ice. Subsequently the mixture was heated to 20° C. and after 1 h the precipitate formed was filtered off. The mother liquor was washed 3× with 200 mL water and dried over sodium sulphate and evaporated down.
[0155] Yield: 83 g of Z1a
[0156] 43 g m-anisidine and 49 mL triethylamine were placed in 400 mL dichloromethane and Z1a dissolved in 200 mL dichloromethane was added dropwise within one hour while cooling with ice. Then the reaction mixture was heated to 20° C. within 12 h, washed 3× with 200 mL ice water, the organic phase was dried and evaporated down. Then the product was purified by fractional distillation in vacuo.
[0157] Yield: 49.6 g of a compound Z1b as a clear oil.
[0158] 48.6 g of the compound Z1b dissolved in 300 ml of water and 47 g 2,4-dichloro-5-nitropyrimidine dissolved in 300 mL ether were combined, then 55.6 g of aqueous potassium hydrogen carbonate solution was added dropwise while cooling with ice. After 48 h the phases were separated and the org. phase was dried over MgSO 4 and evaporated down.
[0159] Yield: 77.0 g of a compound Z1c (bright red oil)
[0160] 77 g of the compound Z1c were dissolved in 500 mL glacial acetic acid and at 60° C. 55 g of iron powder were added batchwise. The mixture was stirred for 1 h at 70° C., then for 45 min at 100° C. and then filtered hot through cellulose. The reaction mixture was combined with approx. 500 mL water and the precipitate was filtered off, suspended in methanol and ether and again filtered off and dried.
[0161] Yield: 37.3 g of a compound Z1d (white crystals)
[0162] 37.3 g of the compound Z1d and 7.7 mL methyl iodide were placed in 250 mL dimethylacetamide and at −10° C. combined with 5.4 g sodium hydride as a 60% dispersion in mineral oil. The mixture was stirred for 120 min at −5° C., then added to 500 mL ice water. The precipitate formed was suction filtered and washed with petroleum ether and water. The still moist crystals were dissolved in methylene chloride, the org. phase was dried and evaporated down. Subsequently the mixture was separated by chromatography on silica gel and the desired fractions were combined.
[0163] Yield: 25.4 g of a compound Z1e (white crystals)
[0164] 1.5 g of Z1e and 1.22 g of tert-butyl 4-amino-3-methoxy-phenyl-carbamate were melted together for 5 h at 120° C. After cooling the reaction mixture was dissolved in dichloromethane and extracted 2× with potassium carbonate solution and 2× with water. After the organic phase had been dried the mixture was separated by silica gel chromatography (eluant 99: 1, CH 2 Cl 2 :MeOH) and the desired product fractions were combined.
[0165] Yield: 0.92 g light brown crystals of a compound Z1f
[0166] 0.92 g Z1f were dissolved in 100 mL methylene chloride, 15 mL trifluoroacetic acid was added and the mixture was stirred for 3 h at 20° C. Then the solution was added to a mixture of 10 g ice and 100 mL of a 25% ammonia solution and the org. phase was extracted with water and evaporated down after drying. The residue was dissolved in acetone and combined with ethereal HCl. The precipitated crystals were filtered off and dried.
[0167] Yield: 0.54 g light brown crystals of the intermediate compound Z1
[0168] The following intermediates were prepared analogously to the synthesis described:
[0169] In order to synthesise Examples 1 to 3 and 13 to 19 first of all an intermediate compound Z6 is prepared as described below.
[0170] 7 g of Z2 were stirred with 4.55 g 4-nitroaniline in 42 mL EtOH, 168 mL water and 1.2 mL 37% hydrochloric acid for 24 h at 90° C. The cooled suspension was adjusted to pH 10 with 12 mL of 4N NaOH and combined with 80 mL dichloromethane. The precipitate was suction filtered and and the org. phase was evaporated down. Then the still damp solid was suspended in methanol, evaporated down and suspended again in ether and the precipitate was filtered off.
[0171] Yield 5.09 g of an intermediate compound Z6a as a yellow solid.
[0172] 5.09 g of Z6a were dissolved in 1500 mL dimethylformamide and hydrogenated with 1.5 g Raney nickel for 3 h at 3.5 bar hydrogen pressure and 50° C. Subsequently the reaction solution was filtered through kieselguhr and the solution was evaporated down. The residue was suspended in ether and filtered again.
[0173] Yield: 4.2 g of Z6 (as a dark green solid)
[0174] In order to synthesis Example 11 first of all an intermediate compound Z7 is prepared as described below.
[0175] A solution of 128.2 g (0.83 mol) D-alanine ethyl ester×HCl and 71.5 g (0.85 mol) cyclopentanone in 1500 mL dichloromethane was combined with 70.1 (0.85 mol) sodium acetate and 265.6 g (1.25 mol) sodium triacetoxyborohydride. The reaction mixture was stirred for 12 h and then poured into 1.5 L of a 10% sodium hydrogen carbonate solution. The aqueous phase was extracted with dichloromethane. The combined organic phases were dried over Na 2 SO 4 and evaporated down.
[0176] Yield: 143.4 g of a compound Z7a (colourless oil)
[0177] 66.0 g of the compound Z7a were placed in 500 mL water and combined with 85.0 g (0.44 mol) 2,4-dichloro-5-nitropyrimidine in 500 mL diethyl ether. At −5° C., 100 mL of 10% potassium hydrogen carbonate solution were added dropwise and the reaction mixture was stirred for 48 h at ambient temperature. The aqueous phase was extracted with diethyl ether, the combined organic phases were dried over Na 2 SO 4 and evaporated down. The dark red solid was stirred with petroleum ether and suction filtered.
[0178] Yield: 88.0 g of a compound Z7b (yellow crystals)
[0179] 88.0 g of the compound Z7b were dissolved in 1000 mL glacial acetic acid and at 60° C. 85 g iron powder were added batchwise, while the temperature rose to 110° C. The mixture was stirred for 1 h at 60° C., then suction filtered hot through cellulose and evaporated down. The brown solid was stirred with 700 mL water and suction filtered.
[0180] Yield: 53.3 g of a compound Z7c (light brown crystals)
[0181] 53.3 g of the compound Z7c were dissolved in 300 mL dimethylacetamide and combined with 13 mL (0.21 mol) methyl iodide. At −5° C. 5.0 g (0.21 mol) sodium hydride were added batchwise as 60% dispersion in mineral oil. After 12 h the reaction mixture was poured onto 1000 mL ice water and the precipitate formed was suction filtered.
[0182] Yield: 40.0 g of a compound Z7d (colourless crystals)
[0183] 1.95 g of Z7d and 1.66 g tert-butyl 4-amino-3-methoxy-phenyl-carbamate were melted together at 120° C. for 4.5 h. After cooling the reaction mixture was dissolved in dichloromethane and extracted 1× with potassium carbonate solution and 2× with water. After drying the org. phase the mixture was separated by silica gel chromatography (eluant 99:1, CH 2 Cl 2 :MeOH) and the product fractions were combined.
[0184] Yield: 1,76 g of the compound Z7e (brown solid)
[0185] 1.75 g of Z7e was dissolved in 100 mL methylene chloride and the solution was combined with 20 mL trifluoroacetic acid. After 12 h stirring at 25° C. the reaction mixture was added to semiconcentrated ammonia solution while being cooled and the org. phase was separated off and extracted with water. After elimination of the solvent the mixture was dissolved in acetone and combined with ethereal HCl. The precipitate formed was filtered off and dried.
[0186] Yield: 1.32 g of the intermediate compound Z7
[0187] In order to synthesise Example 10 first of all an intermediate compound Z8 is prepared as described below.
[0188] 54.0 g (0.52 mol) D-2-aminobutyric acid were suspended in 540 mL methanol and 132 g (1.1 mol) thionyl chloride were slowly added while cooling with ice. The mixture was refluxed for 1.5 h and then evaporated down. The oil remaining was combined with 540 mL tert-butylmethylether and the colourless crystals obtained were suction filtered.
[0189] Yield: 78.8 g of a compound Z8a (colourless crystals)
[0190] 74.2 g of the compound Z8a and 43.5 mL (0.49 mol) cyclopentanone were dissolved in 800 mL dichloromethane. After the addition of 40.0 g (0.49 mol) sodium acetate and 150.0 g (0.71 mol) sodium triacetoxyborohydride at 0° C. the mixture was stirred for 12 h at ambient temperature and then 500 mL 20% sodium hydrogen carbonate solution were added. The aqueous phase was extracted with dichloromethane. The combined organic phases were washed with water, dried over MgSO 4 and evaporated down.
[0191] Yield: 85.8 g of a compound Z8b (light yellow oil)
[0192] 40.0 g of the compound Z8b and 30.0 g (0.22 mol) potassium carbonate were suspended in 600 mL acetone and while cooling with ice combined with 45.0 g (0.23 mol) 2,4-dichloro-5-nitropyrimidine in 200 mL acetone. After 12 h a further 5.0 g of 2,4-dichloro-5-nitropyrimidine were added and the mixture was stirred for 3 h. The reaction mixture was evaporated down, taken up in 800 mL ethyl acetate and 600 mL water and the aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with water, dried over MgSO 4 and evaporated down.
[0193] Yield: 75.0 g of a compound Z8c (brown oil)
[0194] 100 g of the compound Z8c were dissolved in 650 mL glacial acetic acid and at 70° C. 20 g iron powder were added batchwise. The mixture was stirred for 1 h at 70° C., then for 1.5 h at 100° C. and then filtered hot through kieselguhr. The reaction mixture was evaporated down, taken up in methanol/dichloromethane, applied to silica gel and purified by Soxhlet extraction with ethyl acetate. The solvent was removed and the residue was stirred with methanol.
[0195] Yield: 30.0 g of a compound Z8d (light brown crystals)
[0196] 25.0 g of the compound Z8d and 6.5 mL (0.1 mol) methyl iodide were placed in 250 mL dimethylacetamide and at −10° C. 3.8 g (0.95 mol) sodium hydride were added as a 60% dispersion in mineral oil. The mixture was stirred for 20 min. at 0° C., then 30 min. at ambient temperature and finally ice was added. The reaction mixture was evaporated down and combined with 300 mL water. The precipitate formed was suction filtered and washed with petroleum ether.
[0197] Yield: 23.0 g of a compound Z8e (colourless solid)
[0198] 1.5 g Z8e and 1.22 g tert-butyl 4-amino-3-methoxy-phenyl-carbamate were melted together at 120° C. for 5 h. After cooling the reaction mixture was dissolved in dichloromethane and extracted 2× with potassium carbonate solution and 2× with water. After drying the org. phase the mixture was separated by silica gel chromatography (eluant 99:1, CH 2 Cl 2 :MeOH) and the product fractions were combined.
[0199] Yield: 0.92 g of a compound Z8f (light brown crystals)
[0200] 0.92 g Z8f were dissolved in 100 mL methylene chloride, 15 mL trifluoroacetic acid were added and the mixture was stirred for 3 h at 20° C. Then the solution was added to a mixture of 10 g ice and 100 mL of a 25% ammonia solution and the org. phase was extracted with water and evaporated down after drying. The residue was dissolved in acetone and combined with ethereal HCl. The crystals precipitated were filtered off and dried.
[0201] Yield: 0.54 g of the intermediate compound Z8 (light brown crystals)
[0202] In order to synthesise Example 8 first of all an intermediate compound Z9 is prepared as described below.
[0203] A mixture of 73.4 mL ethyl 2-bromoisobutyrate, 87.1 mL 3-methyl-1-butylamine, 82.5 g (0.6 mol) sodium iodide and 76.0 g (0.6 mol) potassium carbonate in 1000 mL ethyl acetate was refluxed for 3 days. Any salts present were filtered off and the filtrate was evaporated down.
[0204] Yield: 97.0 g of a compound Z9a (red oil)
[0205] 49.0 g 2,4-dichloro-5-nitropyrimidine and 38.3 g potassium carbonate were suspended in 500 mL acetone and at 0° C. combined with 93.0 g of the compound Z9a in 375 mL acetone. The reaction mixture was stirred overnight at ambient temperature, filtered and evaporated down. The residue dissolved in ethyl acetate was washed with water and the organic phase was dried over MgSO 4 and evaporated down.
[0206] Yield: 102.7 g of a compound Z9b (brown oil)
[0207] 22.7 g of the compound Z9b were dissolved in 350 mL glacial acetic acid and at 60° C. 17.4 g of iron powder were added batchwise. After the addition had ended the mixture was refluxed for 0.5 h, filtered hot and evaporated down. The residue was taken up in 200 mL dichloromethane/methanol (9:1) and washed with sodium chloride solution. The organic phase was suction filtered through kieselguhr, dried over MgSO 4 , evaporated down and separated by column chromatography (eluant:ethyl acetate/cyclohexane 1:1) and suitable fractions were combined.
[0208] Yield: 1.9 g of a compound Z9c (colourless crystals)
[0209] 1.9 g of the compound Z9c were dissolved in 32 mL dimethylacetamide and while cooling with ice combined with 0.3 g (7 mmol) of sodium hydride as a 60% dispersion in mineral oil. After 10 min. 0.5 mL (7 mmol) of methyl iodide were added and the mixture was stirred for 3 h at ambient temperature. The reaction mixture was evaporated down and combined with water. The precipitate formed was suction filtered and washed with petroleum ether.
[0210] Yield: 1.6 g of a compound Z9d (colourless crystals)
[0211] 1.5 g of Z9d and 1.21 g tert-butyl 4-amino-3-methoxy-phenyl-carbamate were melted together at 120° C. for 4.5 h. After cooling the reaction mixture was dissolved in dichloromethane and extracted 1× with potassium carbonate solution and 1× with water. After drying the org. phase the mixture was separated by silica gel chromatography (eluant 98:2, CH 2 Cl 2 :MeOH) and the product fractions were combined. Yield: 1.12 g of a compound Z9e (light brown solid)
[0212] 1.12 g Z9e was dissolved in 100 mL methylene chloride, 18 mL trifluoroacetic acid were added and the mixture was stirred for 12 h at 20° C. Then the solution was added to a semiconc. ammonia solution and the org. phase was extracted with water and evaporated down.
[0213] Yield: 0.84 g of the intermediate compound Z9 (beige solid)
[0214] The following intermediates were prepared analogously to the methods of synthesis described:
[0215] The new compounds of general formula (I) may be synthesised analogously to the following synthesis examples. These Examples are however intended only as possible methods to illustrate the invention more fully without limiting it to their content.
SYNTHESIS OF THE EXAMPLES
Example 2
[0216] 0.4 g of Z6 were suspended in 8 mL of dichloromethane and 2 mL of chloroform and combined with 0.25 mL of 3-phenylpropionic acid chloride and 0.11 mL of pyridine. After 5 h 10 mL of water were added and the precipitate was washed with water and dichloromethane.
[0217] Yield: 0.50 g as a grey solid
Example 4
[0218] 0.5 g of Z3, 0.547 g of 4-aminoacetanilide were heated to 160° C. in 2 mL sulpholane for 1 h. After cooling, ether and ethyl acetate were added and the solid formed was filtered off. It was then suspended 2× with methanol, acetone and ethyl acetate and the solid was filtered off.
[0219] Yield: 0.24 g as white crystals
Example 8
[0220] 0.1 g of Z9, 79 mg of 4-(4-methyl-piperazin-1-yl)-benzoic acid chloride and 0.2 mL of triethylamine were stirred for 2 h in 2 mL dichloromethane at 20° C., then the org. phase was extracted with 20 mL of 5% aqueous potassium carbonate solution. The org. phase was evaporated down and the mixture was separated by chromatography on silica. The desired fractions were combined and evaporated down and the residue was crystallised from ethyl acetate, diethyl ether and petroleum ether.
[0221] Yield: 0.095 g white crystals
Example 11
[0222] 0.1 g of Z7, 70 mg of 4-(4-methyl-piperazin-1-yl)-benzoic acid chloride and 0.3 mL of triethylamine were stirred for 2 h in 2 mL dichloromethane at 20° C., then the org. phase was extracted with 20 mL of 5% aqueous potassium carbonate solution. The org. phase was evaporated down and the mixture was separated by chromatography on silica. The desired fractions were combined and evaporated down and the residue was crystallised from ethyl acetate and petroleum ether.
[0223] Yield: 0.025 g white crystals
Example 15
[0224] 0.4 g of Z6 was dissolved together with 0.54 g of 4-ethoxycarbonylphenylisocyanate in 8 mL of dimethylformamide and stirred for 3 h at 60° C. Then the solvent was eliminated, the residue was suspended in methylene chloride and filtered off, the residue was again suspended in ether and again filtered off.
[0225] Yield: 0.37 g of a grey solid.
Example 18
[0226] 0.3 g of Z6 was suspended in 4 mL dichloromethane and combined with 0.2 mL diisopropylethylamine. Subsequently 0.15 mL phenyl chloroformate, dissolved in 2 mL dichloromethane, was added dropwise and the mixture was stirred for 4 h at 20° C. Then the solid was filtered off and washed with dichloromethane.
[0227] Yield: 0.26 g as a grey solid
Example 20
[0228] 0.32 g of the compound from Example 15 was suspended in 3 mL ethanol and combined with 2 mL of 1N NaOH. The mixture was then refluxed for 2.5 h. The cooled suspension was combined with 5 mL water and adjusted to about pH 1 with 2 mL of 4N HCl. The suspension was filtered off and washed with water and MeOH.
[0229] Yield: 0.25 g as a grey solid
Example 22
[0230] 0.1 g of Z5 and 0.09 g of tert-butyl 4-amino-3-methoxy-phenyl-carbamate were heated to 120° C. without a solvent for 4 h. The mixture was then taken up in dichloromethane and extracted with water. The organic phase was evaporated down and the mixture was separated by silica gel chromatography. The desired fractions were combined and evaporated down again.
[0231] Yield: 0.06 g
[0232] The compounds of formula (I) listed in Table 1, inter alia, are obtained analogously to the methods described hereinbefore.
[0233] The present invention relates, in particularly preferred embodiments, to the compounds of formula (I), as listed in Table 1, per se, optionally in the form of the tautomers, racemates, enantiomers, diastereomers and mixtures thereof, and optionally in the form of the pharmacologically acceptable acid addition salts, solvates and/or hydrates thereof.
TABLE 1 (I′) Exam- Config. m.p. ple —C*(R 1 R 2 )— —R 1 —R 2 —R 3 —R 4 —L— —R 5 [° C.] 1 — —H —H -Me —H —CH 2 — 220 (decomp.) 2 — —H —H -Me —H —CH 2 —CH 2 — 200 (decomp.) 3 — —H —H -Me —H — >250 4 rac. —H -Me —H — -Me 283 5 R —H -Me —H — -Me 225 6 — —H —H —H — -Me 300 (decomp.) 7 R —H -Me —OMe — 191 8 — -Me -Me —OMe — 194 9 R —H -Me —OMe — 163 10 R —H -Et —OMe — 153 11 R —H -Me —OMe — 246 12 R —H -Et —OMe — 145 13 — —H —H -Me —H —NH—(CH 2 ) 2 — 1) 220 (decomp.) 14 — —H —H -Me —H —NH—CH 2 — >250 15 — —H —H -Me —H —NH— 200 (decomp.) 16 — —H —H -Me —H —NH— >250 17 — —H —H -Me —H —NH— 220 (decomp.) 18 — —H —H -Me —H —O— >250 19 — —H —H -Me —H —O—CH 2 — 1) >250 20 — —H —H -Me —H —NH— 154 21 — —H —H -Me —H —NH— 230 (decomp.) 22 R —H -Me —OMe —O— 191 1) L is linked through the heteroatom to the —NH—CO group;
[0234] As has been found, the compounds of general formula (I) are characterised by their many possible applications in the therapeutic field. Particular mention should be made of those applications for which the inhibition of specific cell cycle kinases, particularly their inhibiting effect on the proliferation of cultivated human tumour cells, and also on the proliferation of other cells, such as e.g. endothelial cells, plays a part.
[0235] As demonstrated by DNA staining followed by FACS analysis, the inhibition of proliferation brought about by the compounds according to the invention is mediated by the arrest of the cells above all in the G2/M phase of the cell cycle. The cells arrest, depending on the cells used, for a specific length of time in this cell cycle phase before programmed cell death is initiated. An arrest in the G2/M phase of the cell cycle is initiated e.g. by the inhibition of specific cell cycle kinases. On the basis of their biological properties the compounds of general formula I according to the invention, their isomers and the physiologically acceptable salts thereof are suitable for treating diseases characterised by excessive or anomalous cell proliferation.
[0236] Such diseases include for example: viral infections (e.g. HIV and Kaposi's sarcoma); inflammatory and autoimmune diseases (e.g. colitis, arthritis, Alzheimer's disease, glomerulonephritis and wound healing); bacterial, fungal and/or parasitic infections; leukaemias, lymphomas and solid tumours; skin diseases (e.g. psoriasis); bone diseases; cardiovascular diseases (e.g. restenosis and hypertrophy). They are also useful for protecting proliferating cells (e.g. hair, intestinal, blood and progenitor cells) from DNA damage caused by radiation, UV treatment and/or cytostatic treatment (Davis et al., 2001). The new compounds may be used for the prevention, short- or long-term treatment of the above-mentioned diseases, also in combination with other active substances used for the same indications, e.g. cytostatics, hormones or antibodies.
[0237] The activity of the compounds according to the invention was determined in the PLK1 inhibition assay, in the cytotoxicity test on cultivated human tumour cells and/or in a FACS analysis, e.g. on HeLa S3 cells. In both test methods the compounds exhibited a good to very good activity, i.e. for example an EC 50 value in the HeLa S3 cytotoxicity test of less than 5 μmol/L, generally less than 1 μmol/L, and an IC 50 value in the PLK1 inhibition assay of less than 1 μmol/L.
[0000] PLK-1 Kinase Assay
[0000] Enzyme Preparation:
[0238] Recombinant human PLK1 enzyme linked to GST at its N-terminal end is isolated from insect cells infected with baculovirus (Sf21). Purification is carried out by affinity chromatography on glutathione sepharose columns.
[0239] 4×10 7 Sf21 cells ( Spodoptera frugiperda ) in 200 ml of Sf-900 II Serum free insect cell medium (Life Technologies) are seeded in a spinner flask. After 72 hours' incubation at 27° C. and 70 rpm, 1×10 8 Sf21 cells are seeded in a total of 180 ml medium in a new spinner flask. After another 24 hours, 20 ml of recombinant Baculovirus stock suspension are added and the cells are cultivated for 72 hours at 27° C. at 70 rpm. 3 hours before harvesting, okadaic acid is added (Calbiochem, final concentration 0.1 μM) and the suspension is incubated further. The cell number is determined, the cells are removed by centrifuging (5 minutes, 4° C., 800 rpm) and washed 1× with PBS (8 g NaCl/l, 0.2 g KCl/l, 1.44 g Na 2 HPO 4 /l, 0.24 g KH 2 PO4/l). After centrifuging again the pellet is flash-frozen in liquid nitrogen. Then the pellet is quickly thawed and resuspended in ice-cold lysis buffer (50 mM HEPES pH 7.5, 10 mM MgCl 2 , 1 mM DTT, 5 μg/ml leupeptin, 5 μg/ml aprotinin, 100 μM NaF, 100 μM PMSF, 10 mM β-glycerolphosphate, 0.1 mM Na 3 VO 4 , 30 mM 4-nitrophenylphosphate) to give 1×10 8 cells/17.5 ml. The cells are lysed for 30 minutes on ice. After removal of the cell debris by centrifugation (4000 rpm, 5 minutes) the clear supernatant is combined with glutathione sepharose beads (1 ml resuspended and washed beads per 50 ml of supernatant) and the mixture is incubated for 30 minutes at 4° C. on a rotating board. Then the beads are washed with lysis buffer and the recombinant protein is eluted from the beads with 1 ml elution buffer/ml resuspended beads (elution buffer: 100 mM Tris/HCl pH=8.0, 120 mM NaCl, 20 mM reduced glutathione (Sigma G-4251), 10 mM MgCl 2 , 1 mM DTT). The protein concentration is determined by Bradford Assay.
[0000] Assay Procedure
[0240] The following components are combined in a well of a 96-well round-bottomed dish (Greiner bio-one, PS Microtitre plate No.650101):
10 μl of the compound to be tested in variable concentrations (e.g. beginning at 300 μM, and dilution to 1:3) in 6% DMSO, 0.5 mg/ml casein (Sigma C-5890), 60 mM β-glycerophosphate, 25 mM MOPS pH=7.0, 5 mM EGTA, 15 mM MgCl 2 , 1 mM DTT 20 μl substrate solution (25 mM MOPS pH=7.0, 15 mM MgCl 2 , 1 mM DTT, 2.5 mM EGTA, 30 mM β-glycerophosphate, 0.25 mg/ml casein) 20 μl enzyme dilution (1:100 dilution of the enzyme stock in 25 mM MOPS pH=7.0, 15 mM MgCl 2 , 1 mM DTT) 10 μl ATP solution (45 μM ATP with 1.11×10 6 Bq/ml gamma-P33-ATP).
[0245] The reaction is started by adding the ATP solution and continued for 45 minutes at 30° C. with gentle shaking (650 rpm on an IKA shaker MTS2). The reaction is stopped by the addition of 125 μl of ice-cold 5% TCA per well and incubated on ice for at least 30 minutes. The precipitate is transferred by harvesting onto filter plates (96-well microtitre filter plate: UniFilter-96, GF/B; Packard; No.6005177), then washed four times with 1% TCA and dried at 60° C. After the addition of 35 μl scintillation solution (Ready-Safe; Beckmann) per well the plate is sealed shut with sealing tape and the amount of P33 precipitated is measured with the Wallac Betacounter. The measured data are evaluated using the standard Graphpad software (Levenburg-Marquard algorithm).
[0000] Measurement of Cytotoxicity on Cultivated Human Tumour Cells
[0246] To measure cytotoxicity on cultivated human tumour cells, cells of cervical carcinoma tumour cell line HeLa S3 (obtained from American Type Culture Collection (ATCC)) were cultivated in Ham's F12 Medium (Life Technologies) and 10% foetal calf serum (Life Technologies) and harvested in the log growth phase. Then the HeLa S3 cells were placed in 96-well plates (Costar) at a density of 1000 cells per well and incubated overnight in an incubator (at 37° C. and 5% CO 2 ), while on each plate 6 wells were filled with medium alone (3 wells as the medium control, 3 wells for incubation with reduced AlamarBlue reagent). The active substances were added to the cells in various concentrations (dissolved in DMSO; DMSO final concentration: 0.1%) (in each case as a triple measurement). After 72 hours incubation 20 μl AlamarBlue reagent (AccuMed International) were added to each well, and the cells were incubated for a further 7 hours. As a control, 20 μl reduced AlamarBlue reagent was added to each of 3 wells (AlamarBlue reagent, which was autoclaved for 30 min). After 7 h incubation the colour change of the AlamarBlue reagent in the individual wells was determined in a Perkin Elmer fluorescence spectrophotometer (excitation 530 nm, emission 590 nm, slits 15 nm, integration time 0.1 ms). The amount of AlamarBlue reagent reacted represents the metabolic activity of the cells. The relative cell activity was calculated as a percentage of the control (HeLa S3 cells without inhibitor) and the active substance concentration which inhibited the cell activity by 50% (IC50) was derived. The values were calculated from the average of three individual measurements—with correction of the dummy value (medium control).
[0000] FACS Analysis
[0247] Propidium iodide (PI) binds stoichiometrically to double-stranded DNA, and is thus suitable for determining the proportion of cells in the G1, S, and G2/M phase of the cell cycle on the basis of the cellular DNA content. Cells in the G0 and G1 phase have a diploid DNA content (2N), whereas cells in the G2 or mitosis phase have a 4N DNA content.
[0248] For PI staining, for example, 0.4 million HeLa S3 cells were seeded onto a 75 cm 2 cell culture flask, and after 24 h either 0.1% DMSO was added as control or the substance was added in various concentrations (in 0.1% DMSO). The cells were incubated for 24 h with the substance or with DMSO before the cells were washed 2× with PBS and then detached with trypsin/EDTA. The cells were centrifuged (1000 rpm, 5 min, 4° C.), and the cell pellet was washed 2× with PBS before the cells were resuspended in 0.1 ml PBS. Then the cells were fixed with 80% ethanol for 16 hours at 4° C. or alternatively for 2 hours at −20° C. The fixed cells (10 6 cells) were centrifuged (1000 rpm, 5 min, 4° C.), washed with PBS and then centrifuged again. The cell pellet was resuspended in 0.25% Triton X-100 in 2 ml PBS, and incubated on ice for 5 min before 5 ml PBS were added and the mixture was centrifuged again. The cell pellet was resuspended in 350 μl PI staining solution (0.1 mg/ml RNase A, 10 μg/ml propidium iodide in 1× PBS). The cells were incubated for 20 min in the dark with the staining buffer before being transferred into sample measuring containers for the FACS scan. The DNA measurement was carried out in a Becton Dickinson FACS Analyzer, with an argon laser (500 mW, emission 488 nm), and the DNA Cell Quest Programme (BD). The logarithmic PI fluorescence was determined with a band-pass filter (BP 585/42). The cell populations in the individual cell cycle phases were quantified using the ModFit LT Programme made by Becton Dickinson.
[0249] The compounds according to the invention were also tested accordingly for other tumour cells. For example, these compounds are effective on carcinomas of many diferent kinds of tissue (e.g. breast (MCF7); colon (HCT116), head and neck (FaDu), lung (NCI-H460), pancreas (BxPC-3) and prostate (DU145)), sarcomas (e.g. SK-UT-1B), leukaemias and lymphomas (e.g. HL-60; Jurkat, THP-1) and other tumours (e.g. melanomas (BRO), gliomas (U-87MG)) and could be used for such indications. This is evidence of the broad applicability of the compounds according to the invention for the treatment of many diferent kinds of tumour types.
[0250] The compounds of general formula (I) may be used on their own or in conjunction with other active substances according to the invention, optionally also in conjunction with other pharmacologically active substances. Suitable preparations include for example tablets, capsules, suppositories, solutions, particularly solutions for injection (s.c., i.v., i.m.) and infusion, elixirs, emulsions or dispersible powders. The content of the pharmaceutically active compound(s) should be in the range from 0.1 to 90 wt.-%, preferably 0.5 to 50 wt.-% of the composition as a whole, i.e. in amounts which are sufficient to achieve the dosage range specified below. The doses specified may, if necessary, be given several times a day.
[0251] Suitable tablets may be obtained, for example, by mixing the active substance(s) with known excipients, for example inert diluents such as calcium carbonate, calcium phosphate or lactose, disintegrants such as corn starch or alginic acid, binders such as starch or gelatine, lubricants such as magnesium stearate or talc and/or agents for delaying release, such as carboxymethyl cellulose, cellulose acetate phthalate, or polyvinyl acetate. The tablets may also comprise several layers.
[0252] Coated tablets may be prepared accordingly by coating cores produced analogously to the tablets with substances normally used for tablet coatings, for example collidone or shellac, gum arabic, talc, titanium dioxide or sugar. To achieve delayed release or prevent incompatibilities the core may also consist of a number of layers. Similarly the tablet coating may consist of a number or layers to achieve delayed release, possibly using the excipients mentioned above for the tablets.
[0253] Syrups or elixirs containing the active substances or combinations thereof according to the invention may additionally contain a sweetener such as saccharine, cyclamate, glycerol or sugar and a flavour enhancer, e.g. a flavouring such as vanillin or orange extract. They may also contain suspension adjuvants or thickeners such as sodium carboxymethyl cellulose, wetting agents such as, for example, condensation products of fatty alcohols with ethylene oxide, or preservatives such as p-hydroxybenzoates.
[0254] Solutions for injection and infusion are prepared in the usual way, e.g. with the addition of isotonic agents, preservatives such as p-hydroxybenzoates, or stabilisers such as alkali metal salts of ethylenediamine tetraacetic acid, optionally using emulsifiers and/or dispersants, whilst if water is used as the diluent, for example, organic solvents may optionally be used as solvating agents or dissolving aids, and transferred into injection vials or ampoules or infusion bottles.
[0255] Capsules containing one or more active substances may for example be prepared by mixing the active substances with inert carriers such as lactose or sorbitol and packing them into gelatine capsules. Suitable suppositories may be made for example by mixing with carriers provided for this purpose, such as neutral fats or polyethyleneglycol or the derivatives thereof.
[0256] Excipients which may be used include, for example, water, pharmaceutically acceptable organic solvents such as paraffins (e.g. petroleum fractions), vegetable oils (e.g. groundnut or sesame oil), mono- or polyfunctional alcohols (e.g. ethanol or glycerol), carriers such as e.g. natural mineral powders (e.g. kaolins, clays, talc, chalk), synthetic mineral powders (e.g. highly dispersed silicic acid and silicates), sugars (e.g. cane sugar, lactose and glucose), emulsifiers (e.g. lignin, spent sulphite liquors, methylcellulose, starch and polyvinylpyrrolidone) and lubricants (e.g. magnesium stearate, talc, stearic acid and sodium lauryl sulphate).
[0257] The preparations are administered by the usual methods, preferably by oral or transdermal route, most preferably by oral route. For oral administration the tablets may, of course contain, apart from the abovementioned carriers, additives such as sodium citrate, calcium carbonate and dicalcium phosphate together with various additives such as starch, preferably potato starch, gelatine and the like. Moreover, lubricants such as magnesium stearate, sodium lauryl sulphate and talc may be used at the same time for the tabletting process. In the case of aqueous suspensions the active substances may be combined with various flavour enhancers or colourings in addition to the excipients mentioned above.
[0258] For parenteral use, solutions of the active substances with suitable liquid carriers may be used.
[0259] The dosage for intravenous use is from 1-1000 mg per hour, preferably between 5 and 500 mg per hour.
[0260] However, it may sometimes be necessary to depart from the amounts specified, depending on the body weight, the route of administration, the individual response to the drug, the nature of its formulation and the time or interval over which the drug is administered. Thus, in some cases it may be sufficient to use less than the minimum dose given above, whereas in other cases the upper limit may have to be exceeded. When administering large amounts it may be advisable to divide them up into a number of smaller doses spread over the day.
[0261] In another aspect the present invention relates to pharmaceutical formulations, preferably pharmaceutical formulations of the type described above, characterised in that they contain one or more compounds of general formula (I).
[0262] The formulation examples which follow illustrate the present invention without restricting its scope:
EXAMPLES OF PHARMACEUTICAL FORMULATIONS
[0263]
A)
Tablets
per tablet
active substance
100 mg
lactose
140 mg
corn starch
240 mg
polyvinylpyrrolidone
15 mg
magnesium stearate
5 mg
500 mg
[0264] The finely ground active substance, lactose and some of the corn starch are mixed together. The mixture is screened, then moistened with a solution of polyvinylpyrrolidone in water, kneaded, wet-granulated and dried. The granules, the remaining corn starch and the magnesium stearate are screened and mixed together. The mixture is compressed to produce tablets of suitable shape and size.
B) Tablets per tablet active substance 80 mg lactose 55 mg corn starch 190 mg microcrystalline cellulose 35 mg polyvinylpyrrolidone 15 mg sodium-carboxymethyl starch 23 mg magnesium stearate 2 mg 400 mg
[0265] The finely ground active substance, some of the corn starch, lactose, microcrystalline cellulose and polyvinylpyrrolidone are mixed together, the mixture is screened and worked with the remaining corn starch and water to form a granulate which is dried and screened. The sodium-carboxymethyl starch and the magnesium stearate are added and mixed in and the mixture is compressed to form tablets of a suitable size.
C) Ampoule solution active substance 50 mg sodium chloride 50 mg water for inj. 5 ml
[0266] The active substance is dissolved in water at its own pH or optionally at pH 5.5 to 6.5 and sodium chloride is added to make it isotonic. The solution obtained is filtered free from pyrogens and the filtrate is transferred under aseptic conditions into ampoules which are then sterilised and sealed by fusion. The ampoules contain 5 mg, 25 mg and 50 mg of active substance.
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Disclosed are new dihydropteridinones of general formula (I)
whereby the groups L, R 1 , R 2 , R 3 , R 4 and R 5 have the meanings given in the claims and specification, the isomers thereof, processes for preparing these dihydropteridinones and their use as pharmaceutical compositions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a synchronization protecting system for signals received in a radio base station.
2. Description of the Related Art
With the spread of recent movable or cellar communication systems, there is a demand for more reliability on a radio channel quality. To meet the demand, it is required to protect a radio channel quality by a synchronization protecting method having high ability.
In a prior method for protecting synchronization of signals received in a radio base station, which has been developed by the present applicant, a first synchronized word detecting window AP 1 for the use to establish an initial synchronization is provided to cover a position of a synchronized word SW of a signal received from a cellar station, which is prescribed for a reference timing for transmission in the radio base station.
The synchronized word SW is detected in the first synchronized word detection window AP 1 . On the other hand, the position of synchronized word SW of the reception signal transmitted from the cellar station differs in every time a signal is received, according to a distance between the radio base station and the cellar station or a state of propagating radio waves. Accordingly, a width of the first synchronized word detecting window AP 1 for use to establish an initial synchronization requires a width enough to cover the difference of the positions of the synchronized words SW of reception signals to certain extent.
However, once the synchronization is established, it can be predicted that the position of detecting the synchronized word SW is not widely changed at the time when the synchronized word SW is detected, namely, when the synchronization establishment is maintained after that.
Alternatively, to prevent from detecting the synchronized word by mistake in the first synchronized word detecting window AP 1 having a wider width, a second synchronized word detecting window AP 2 , of which width is narrower than that of the first synchronized word detecting window AP 1 is provided, based on a position of detecting an initial synchronized word detected in the first synchronized word detecting window AP 1 .
In other words, the second synchronized word detecting window AP 2 protects the synchronized word SW detection, which is detected in the first synchronized word detecting window AP 1 . Once the second synchronized word detecting window AP 2 becomes effective at the time of establishing an initial synchronization, a relationship of position with the first synchronized word detecting window AP 1 is not changed, until there is no need to maintain the synchronization by finishing the communication with the cellar station.
In the method developed by the present applicant before, there is no means to change the position of setting the second synchronized word detecting window AP 2 at the time when the position of detecting the synchronized word is larger than the width of the second synchronized word detecting window AP 2 , because the timing of receiving the signal from the cellar station is widely changed in the state the synchronization is once established.
Although the first synchronized word-detecting window AP 1 can detect the synchronized word SW, the position of detecting the synchronized word is not within the second synchronized word-detecting window AP 2 . Therefore, that brings a problem such that the result of detecting in the second synchronized word-detecting window AP 2 becomes inactive state.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a synchronization protecting and setting system for signals received in a radio base station, whereby a protection of the synchronized word SW detected by a first synchronized word detecting window AP 1 can be maintained in a second synchronized word detecting window AP 2 , by improving the previously produced system.
The above-described objects can be achieved by a synchronization protecting and setting system for signals received in a radio base station including a first means generating a first synchronized word detecting window, which covers a position of a synchronized word in a reception signal for a reference timing of transmission in the radio base station; a second means generating a second synchronized word detecting window, which covers the position of the synchronized word in the first synchronized word detecting window; a means for detecting a synchronized word in the first or second synchronized word detecting window; and a control means for resetting the position of the second synchronized word detecting window under a predetermined condition.
In one detailed mode, the second synchronized word-detecting window is controlled so that when the synchronized word detecting means detects the synchronized word in the first synchronized word detecting window, the synchronized word is detected within the second synchronized word detecting window in a next frame.
In second detailed mode, the synchronized word is formed of plural bits, and the control means resets the position of the second synchronized word detecting window, when a bit error rate of the synchronized word is more than a predetermined value.
Further, in a third detailed mode, the reception signal includes a color code formed of plural bits, and the control means resets the position of the second synchronized word detecting window, when a bit error rate of the color code is more than a predetermined value.
Furthermore, in a fourth detailed mode, the control means resets the second synchronized word detecting window, when a difference of phases in the number of frames of the signals received in the radio base station is more than a predetermined value.
Additionally, in a fifth detailed mode, when the result of BCH decoding for signals received in the radio base station is mistaken, the control means resets the second synchronized word detecting window.
Alternatively, in a sixth detailed mode, when the result of CRC arithmetic for the signals received in the radio base station is mistaken, the control means resets the second synchronized word detecting window.
Furthermore, in a seventh detailed mode, the control means resets the second synchronized word detecting window, when the signal received in the radio base station is less than a predetermined value.
Further, other objects of the present invention become clear by the description for explaining embodiments according to the attached drawings.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
FIG. 1 is a structural block diagram of a radio base station according to the present invention.
FIG. 2A shows a physical channel format of the digital reception signal, and FIG. 2B shows signals in each section.
FIG. 3 is a structural diagram of one embodiment of the present invention, in which a received section of the radio base station is illustrated.
FIG. 4 shows a relationship of phase values for positions of synchronized word SW detecting pulse in the first synchronized word-detecting window AP 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, preferred embodiments of the present invention will be now described in reference to the drawings. Throughout the attached drawings, the same reference numerals and symbols are used to denote and identify corresponding or identical components.
FIG. 1 is a block diagram of a structural example of a radio base station according to the present invention. The radio base station receives a radio signal (a) transmitted from a cellar station, not shown in the diagram. A demodulator 1 in the radio base station converts the received radio signal (a) into a digital reception signal (b). The demodulator 1 detects a level of the received radio signal and stores the level in a register 2 of the demodulator 1 . A CPU 3 can read out the level stored in the register 2 later.
The radio base station further includes a synchronizing section 100 having an AP 1 generator 5 , which generates a first synchronized word detecting window AP 1 (c), according to reference timing and CLK (g) transmitted from a timing generator 4 .
The synchronizing section 100 further has a synchronized word detecting section 6 , which detects a synchronized word and color code of the digital reception signal (b) in the first synchronized word detecting window AP 1 (c) transmitted from the AP 1 generator 5 .
In the embodiment, the synchronized word and color code of the digital reception signal (b) will be explained according to FIGS. 2A and 2B . FIG. 2A shows a physical channel format of the digital reception signal (b), and FIG. 2B shows signals in each section.
In FIG. 2A , a format of the digital reception signal (b) for one frame is shown. One frame is formed of 280 bits, of which 20 bits are for the synchronized word SW, and 8 bits are for the color code CC.
Therefore, the detection of the synchronized word SW or color code CC in the synchronized word detector 6 is determined by judging whether the synchronized word SW or color code CC is coincident with each predetermined bit pattern or not. Additionally, the signal format includes data sections, which are respectively in front of the synchronized word SW and behind the color code CC.
In this example, the synchronized word is necessary to establish a timing of receiving signals in the base station, and the color code CC is an interference countermeasure code allocated in each cluster, which is a frequency repeating unit, for distinguishing radio signals transmitted from an interference station. Each eight bits are allocated as a color code CC in a frame of all radio burst signals. 255 of the same patterns except a pattern of “00” are employed for upward and downward channels.
(b) of FIG. 2B is a reference timing of generating the first synchronized word detecting window AP 1 , i.e., a clock synchronized to a transmission reference timing in the radio base station, and a relationship of phases between the reference timing and the first synchronized word detecting window AP 1 , shown in (c) of FIG. 2B , is always fixed.
As described above, a position of detecting pulse of the synchronized word SW, shown in (d) of FIG. 2B , is changed in the first synchronized word detecting window AP 1 , according to the change of phase of the digital reception signal (b).
Returning back to FIG. 1 , the synchronized word detector 6 stores the numbers of error bits of the synchronized word SW and color code CC, which are detected in the first synchronized word detecting window AP 1 in a synchronizing register 7 . The numbers of error bits of the synchronized word and color codes CC stored in the synchronizing register 7 can read out by the CPU 3 . Concurrently, phase information of the synchronized word detecting pulse, i.e., position information of the detecting pulse of the synchronized word SW, as shown in (d) of FIG. 2B , is stored in the synchronizing register 7 , so as to be read out by the CPU 3 .
Additionally, the synchronizing register 7 includes a writing register, not shown in the diagram, which writes a signal for resetting the second synchronized word detecting window generator 8 . The second synchronized word detecting window generator 8 generates a second synchronized word detecting window AP 2 corresponding to (e) of FIG. 1 and (e) of FIG. 2B , of which width is narrower than that of the first synchronized word detecting window AP 1 , around the first synchronized word detecting pulse corresponding to (d) of FIG. 1 and (d) of FIG. 2B , detected in the synchronized word detector 6 .
Once the generation of second synchronized word detecting window AP 2 is started, a relationship of phases between the first and second synchronized word detecting windows AP 1 and AP 2 is not changed, regardless of existence of the first synchronized word detecting pulse (d) from the next frame.
A signal for resetting the second synchronized word detecting window generator 8 is written in the synchronizing register 7 . Only when the second synchronized word detecting window generator 8 is reset by the resetting signal, a position of generating the second synchronized word detecting window AP 2 , of which width is narrower than that of the first synchronized word detecting window AP 1 , around the next synchronized word detecting pulse (d).
In other words, it is apparent from FIG. 2 that the second synchronized word detecting window AP 2 prevents from detecting the synchronized word SW from being mistakenly detected in the first synchronized word detecting window AP 1 . When the synchronized word SW is detected at first time, the second synchronized word detecting window generator 8 generates the second synchronized word detecting window AP 2 around the position of the detected pulse (d) of the synchronized word SW.
After that, the relationship of phases between the first and second synchronized word detecting windows AP 1 and AP 2 is not changed, until the second synchronized word detecting window generator 8 is reset by the resetting signal.
Additionally, a DET pulse generator 9 outputs a determination (DET) pulse (f), according to an AND condition of the synchronized word detecting pulse (d) and the second synchronized word detecting window AP 2 in FIG. 1 .
The DET pulse generator 9 generally outputs the DET pulse (f), according to the AND condition of the synchronized word SW detecting pulse (d) and the second synchronized word detecting window AP 2 . When the synchronized word SW detector 6 can not detect the synchronized word SW, the DET pulse generator 9 generates the DET pulse (f) at a center of the second synchronized word detecting window AP 2 and outputs the generated DET pulse.
Although the synchronized word SW detecting pulse (d) is within the first synchronized word detecting window AP 1 , however, the DET pulse (f) is not output, when the pulse is outside of the width of second synchronized word detecting window AP 2 .
In FIG. 1 , a reception signal processor 200 includes a data extracting section 10 , which inputs the digital reception signal (b) transmitted from the demodulator 1 , extracts the data according to the DET pulse (f) transmitted from the DET pulse generator 9 and the reference timing transmitted from the timing generator 4 , and stores it in a buffer 11 .
In the reception signal processor 200 , the data stored in the buffer 11 is deinterlieved in a deinterlieving processor 12 , based on the digital cellar telephone system standard (RCRSTD-27). The deinterlieving process is that the data of the reception signal, which is written in vertical, is changed back to an original ordered signal by reading the data in horizontal.
Then, a BCH demodulator 13 performs BCH decoding for the data deinterlieved in the deinerleaving processor 12 , based on the digital cellar telephone system standard (RCRSTD-27). Additionally, the decoding result is stored in the reception signal-processing register 14 .
A CRC arithmetic section 15 performs CRC arithmetic for the data BCH decoded in the BCH demodulator 13 , based on the digital cellar telephone system standard (RCRSTD-27), and outputs the result. The BCH demodulator 13 further stores the result in the reception signal-processing register 14 , similarly to the case of the BCH demodulator 13 .
In FIG. 1 , the timing generator 4 generates a reference timing and CLK signals required for processes in the synchronizing section 100 and the reception signal processor 200 , and supplies timings (i), which are respectively used to read out data of the registers 2 , 7 and 14 to the CPU 3 .
The CPU 3 monitors the registers 2 , 7 and 14 , according to the read out timing (i) transmitted from the timing generator 4 . The CPU 3 further reads out the number of bit errors of the synchronized words, which is set in the synchronizing register 7 , and the number of bit errors of the color code, and calculates a bit error rate for the number of each optional frames, according to the numbers read out.
Although it will be later described in detail, a memory 16 stores a condition of resetting the second synchronized word detecting window generator 8 , in FIG. 1 . The CPU 3 judges whether the calculated bit error rate is coincident or not, according to the condition of resetting the second synchronized word detecting window generator 8 , which is stored in the memory 16 . The result of judgement is written, as resetting data, in a second synchronized word detecting window generator resetting register, not shown in the diagram, of the synchronizing resistor 7 .
The above described case where the calculated bit error rate is coincident to the condition of resetting the second synchronized word detecting window generator 8 will be now explained as one embodiment as follows.
As shown in FIG. 1 , the CPU 3 reads out the number of errors of the synchronized word SW, which is set in the synchronizing register 7 in each frame, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 .
Then, the CPU 3 calculates the bit error rate in N frames, according to the number of errors of the synchronized word SW. The CPU 3 controls the AP 2 generator resetting register of the synchronizing register 7 , not shown in the diagram, to reset the second synchronized word detecting window generator 8 on the condition of resetting the second synchronizing word detecting window generator 8 set in the memory 16 that the bit error rate of synchronizing words is more than X%.
Then, the CPU 3 changes a position of generating the second synchronizing word detecting window AP 2 , based on a position of synchronized word detecting pulse (d) in the second synchronized word detecting window AP 2 . Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
An example of calculating the bit error rate of the synchronized words will be now explained as one embodiment. FIG. 3 is a structural block diagram of one embodiment according to the present invention, in which a receiving section of the radio base station is illustrated. In FIG. 3 , the same reference numerals and symbols are used to denote and identify corresponding or identical components shown in FIG. 1 , and structures of the synchronizing section 100 and the reception signal processor 200 are respectively provided corresponding to plural slots (S 0 to Sn) of the reception signal.
In the embodiment of FIG. 3 , the CPU 3 monitors the receiving sections for each slot, respectively. Thereby, the second synchronized word detecting window generator 8 can be reset in each slot, according to the condition of resetting the second synchronized word detecting window generator 8 in each slot. The example of calculating the condition of resetting the second synchronized word detecting window generator 8 in this structure will be now described as follows.
Assuming that the number of errors of the synchronized words SW for each optional continuous 6 frames as D 1 , D 2 , D 3 , D 4 , D 5 and D 6 , the error rate is calculated in each 3 frames. For example, it is possible to calculate a first error rate by using an average value of D 1 , D 2 and D 3 and to calculate a next error rate by using an average value of D 4 , D 5 and D 6 . Alternatively, it is also possible to calculate the first error rate by using an average value of D 1 , D 2 and D 3 , and to calculate the next error rate by using an average value of D 2 , D 3 and D 4 .
To be concretely, the number of errors of synchronized word can be expressed by the number of error bits included in the number of bits (20) of the synchronized word SW in one frame (the maximum value is 20). The number of errors of the synchronized words SW in the continuous 6 frames (D 1 to D 6 ) are respectively 2, 1, 0, 0, 1, 1, for example.
When calculating the error rate in each three frames, the first error rate is calculated as an average value of D 1 , D 2 and D 3 and the next error rate is calculated as an average value of D 4 , D 5 and D 6 .
Then, these error rates can be expressed as follows:
First error rate = A number of errors of SW in 3 frames ( D1 + D2 + D3 ) Total number of bits of SW in 3 frames ( 60 ) × 100 ( % ) = 3 60 × 100 = 5 ( % ) Next error rate = A number of errors of SW in 3 frames ( D4 + D5 + D6 ) Total numer of bits of SW in 3 frames ( 60 ) × 100 ( % ) = 2 60 × 100 = 3.3 ( % )
In the example that the second synchronized word detecting window generator 8 is reset, an error rate of color code CC will be now calculated. As shown in FIG. 1 , the CPU 3 reads out the number of errors of the color code of the synchronizing register 7 in each frame, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 . Then, the CPU 3 calculates the bit error rate in N frames.
The calculated bit error rate is compared with an error rate X% of color code CC, which is a condition of resetting the second synchronized word detecting window generator 8 stored in the memory 16 . The second synchronized word detecting window generator 8 is reset through the second synchronized word detecting window generator resetting register of the synchronizing register 7 , which is not shown in the diagram, under a reset condition that the calculated bit error rate of color code CC is more than the error rate X% of color code CC.
The position of generating the second synchronized word detecting window AP 2 is changed by the reset operation, based on the position of the synchronizing word detecting pulse (d) in the first synchronized word detecting window AP 1 at that time. Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
As a third method of resetting the second synchronized word detecting window generator 8 , the reset operation can be performed, based on the result of BCH decoding.
As shown in FIG. 1 , the CPU 3 reads out the result of BCH decoding stored in the reception signal processing register 14 in each frame, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 . When the result fulfills the condition of the BCH decoding result for resetting the second synchronized word detecting window generator 8 set in the memory 16 , the second synchronized word detecting window generator 8 is reset through the second synchronized word detecting window generator resetting register, not shown in the diagram.
Thereby, the position of generating the second synchronized word detecting window AP 2 is changed, based on the position of the synchronized word detecting pulse (d) in the first synchronized word detecting window AP 1 .
In other words, when the CPU 3 detects that the error continuously occurs more than N times, or detects the error occurs more than N times in the N frames, the CPU 3 controls the second synchronized word window generator resetting register, not shown in the diagram, to reset the second synchronized word detecting window generator 8 . Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
As a fourth method of resetting the second synchronized word detecting window generator 8 , the reset operation can be performed, based on the result of CRC arithmetic, similarly with the case of using the BCH decoding result.
In other words, the CPU 3 reads out the result of CRC arithmetic of the reception signal processing register 14 in each CRC arithmetic process of each functional channel of the received data, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 .
When the result of CRC arithmetic fulfills the condition of resetting the second synchronized word detecting window generator 8 , which is set in the memory 16 , the second synchronized word detecting window generator 8 is reset through the second synchronized word detecting window generator resetting register of the synchronizing register 7 .
Thereby, the position of generating the second synchronized word detecting window AP 2 is changed, based on the position of the synchronized word detecting pulse (d) in the first synchronized word detecting window AP 1 at that time. Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
When the CRC arithmetic result fulfils the condition of resetting the second synchronized word detecting window generator 8 , i.e., at the time the CPU 3 detects that the error continuously occurs more than N times in each result of CRC arithmetic or at the time the CPU 3 detects the error occurs more than N times in N frames, for example, the CPU 3 controls the second synchronized word detecting window generator resetting register to reset the second synchronized word detecting window generator 8 .
Additionally, it is possible to control the resetting operation, based on a phase of detecting the synchronized words SW, as a fifth method of resetting the second synchronized word detecting window generator 8 .
In other words, as shown in FIG. 1 , the CPU 3 reads out a phase value of detecting the synchronized word of the synchronizing register 7 in each frame, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 . Then, the CPU 3 calculates the phase value of detecting the synchronized word in N frames.
The calculated phase value of detecting the synchronized words is compared with a difference X of an average value of phases of detecting the synchronized word, which is the condition of resetting the second synchronized word detecting window generator 8 set in the memory 16 . When the calculated phase value of detecting the synchronized word is more than the difference X of the average value of phases of detecting the synchronized words, the condition of resetting the second synchronized word detecting window generator 8 fulfills.
Then, the second synchronized word detecting window generator 8 is reset through the second synchronized word detecting window generator resetting register, not shown in the diagram, of the synchronizing register 7 . The position of generating the second synchronized word detecting window AP 2 is changed, based on the position of the synchronized word detecting pulse (d) in the first synchronized word detecting window AP 1 at that time. Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
The fifth method will be further explained according to a detailed example. FIG. 4 shows a relationship of phase values for each position of the detecting pulse (d) of the synchronized word SW in the first synchronized word-detecting window AP 1 .
The second synchronized word detecting window generator 8 is reset under the resetting condition that the difference of the average of phase values in each five frames is more than “1”. As one example, the phase values of the synchronized word detecting pulse in optional 10 frames are shown as follows.
The first frame phase : 0 The second frame phase : 0 The third frame phase : - 1 The fourth frame phase : 0 The fifth frame phase : + 1 } Average phase 0.4 The sixth frame phase : + 1 The seventh frame phase : + 1 The eighth frame phase : + 2 The ninth frame phase : + 2 The tenth frame phase : + 2 } Average phase 1.6 } Difference 1.2
In the above-described example, the average value of the first five frames is 0.4, and the average value of the next five frames is 1.6. Therefore, the difference is 1.2. The result fulfills the condition that the difference is more than “1”. Thereby, the second synchronized word detecting window generator 8 is reset.
In here, the average value of phases of the first to the fifth frames and the average value of phases of the sixth to tenth frames can be respectively obtained from the following relational equations:
Average value of phases of first to fifth frames = Sum of phases for the number of frames for obtaining average value ( ± is omitted ) the number of frames for obtaining average value = 2 5 = 0.4
Average value of phases of sixth to tenth frames = Sum of phases for the number of frames for obtaining average value ( ± is omitted ) The number of frames for obtaining average value = 8 5 = 1.6
A difference between the average value of phases of the first to fifth frames and the average value of phases of the sixth to tenth frames can be expressed as: 0.4−1.6=1.2 (where ± is omitted).
Next, as a sixth embodiment of resetting the second synchronized word detecting window generator 8 , the resetting operation can be performed, based on a received state of the reception signal.
In other words, the CPU 3 reads out a reception level of the demodulating register 2 in each frame, according to the read out timing (i) of the synchronizing register 7 transmitted from the timing generator 4 , as shown in FIG. 1 .
Then, the CPU 3 calculates an average of the read out reception levels in N frames. The reception level X, which is a condition of resetting the second synchronized word detecting window generator 8 stored in the memory 16 , is compared with the calculated average reception level.
When the average reception level fulfills a resetting condition that the level is less than a reception level X, the second synchronized word detecting window generator 8 is reset through the second synchronized word detecting window generator resetting register, not shown in the diagram, of the synchronizing register 7 . Thereby, the position of generating the second synchronized word detecting window AP 2 can be changed, based on the position of the synchronized word detecting pulse (d) in the first synchronized word detecting window AP 1 at that time. Therefore, it becomes possible to prevent from missing protection against the synchronized word detecting pulse (d) by the second synchronized word-detecting window AP 2 .
As the embodiments according to the present invention are explained in accompanying to the attached drawings, it becomes possible to maintain establishing a synchronization, regardless of the state, even when phases of signals received in a radio base station are widely changed. Thereby, the present invention can improve performance of receiving signals in a radio base station.
The invention may be embodied in other specific forms without departing from the sprit or essential characteristics thereof. The present embodiment is therefore to be considered in all aspects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A synchronization protecting and setting system for signals received in a radio base station whereby a protection of synchronized word SW detected in a first synchronized word detecting window AP 1 can be maintained in a second synchronized word detecting window AP 2 is provided. The synchronization protecting and setting method for signals received in a radio base station comprises a first unit generating a first synchronized word detecting window, which covers a position of synchronized word in a reception signal for a reference timing for transmission in the radio base station; a second unit generating a second synchronized word detecting window, which covers the position of the synchronized word in the first synchronized word detecting window; a synchronized word detecting unit detecting the synchronized word in the first or second synchronized word detecting window; and a controller resetting a position of the second synchronized word detecting window in the first synchronized word detecting window, in a predetermined condition.
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RELATED APPLICATION DATA
[0001] This application claims priority under 35 U.S.C. §119 to EP Patent Application No. 14170923.8, filed on Jun. 3, 2014, which the entirety thereof is incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates to a method of manufacturing a cutting tool and to a cutting tool having a cutting edge having a variation of edge rounding along the cutting edge of the cutting tool.
BACKGROUND
[0003] Cutting tools are used in machining of materials, preferably metallic materials, in various types of machining operations, e.g. turning, drilling and milling operations. During machining, different portions of the cutting edge of a cutting tool may be subjected to very different machining conditions, e.g. related to cutting speed, uncut chip thickness etc.
[0004] Therefore it may be desirable to optimize different portions of the cutting edge for different machining conditions in order to optimize the cutting performance for the cutting tool. It may be desirable to provide a stronger edge at portions of the cutting edge where the cutting speed is lower or the uncut chip thickness is larger and a sharper edge where the cutting speed is higher or the uncut chip thickness is smaller.
[0005] In view of this, EP 2484467 A1 discloses a cutting insert having a cutting edge with a first radius at a first point of the cutting edge, and a different second radius at second point along the cutting edge. It is disclosed that the edge radii may be formed by a brushing operation.
[0006] To form the cutting edge disclosed in EP 2484467 A1 having the different first and second radii at different portions along the cutting edge by means of brushing, different degrees of brushing at the different portions are needed, implying a complex manufacturing procedure.
[0007] Thus it is desirable to provide an improved method of manufacturing a cutting tool to provide a variation of edge rounding along the cutting edge, and to provide a cutting tool which enables a simplified manufacturing in order to obtain a variation of edge rounding along the cutting edge.
SUMMARY
[0008] An aspect of the present disclosure is to provide a cutting tool and a method of manufacturing a cutting tool where a variation of the edge rounding along the cutting edge may be achieved by simple, fast and reliable processing means.
[0009] Thus the disclosure relates to a method of manufacturing a cutting tool, comprising the steps of:
[0000] providing a cutting tool blank including a cutting edge. The cutting edge is defined by a cross-sectional wedge angle, which has a variation along the cutting edge. The method further comprises removing material from the cutting edge, with a constant material removal rate per length unit of the edge, such as to form a corresponding variation of edge rounding along the cutting edge.
[0010] Thereby the method provides a simple, fast and reliable way of achieving a cutting tool having a variation of the edge rounding along the cutting edge. By removing material from the cutting edge with a constant material removal rate per length unit of the edge, the variation of wedge angle along the edge will provide a variation of edge rounding along the cutting edge. The obtained variation of edge rounding along the cutting edge thus corresponds to the variation of the wedge angle along the cutting edge. A larger wedge angle will result in a larger radius of the edge rounding, forming a stronger edge, and a smaller wedge angle will result in a smaller radius of the edge rounding, forming a sharper edge.
[0011] The material may be removed by wet blasting, dry blasting, brushing, electro discharge machining or laser processing (e.g. laser ablation). Since these methods may be used to provide a constant material removal rate per length unit of the edge, the processing parameters of the methods may be maintained constant over the cutting edge, simplifying the processing.
[0012] The constant material removal rate may be within the range of 100-600 μm 2 per length unit of the edge per unit of time, preferably within the range of 200-500 μm 2 per length unit of the edge per unit of time, more preferably within the range of 300-400 μm 2 per length unit of the edge per unit of time. Thereby a suitable range of edge radii may be achieved.
[0013] The cutting edge may have a constant edge radius in a cross-section of the cutting edge, i.e. formed by a circular segment, or the edge radius may vary in a cross-section of the cutting edge, i.e. forming an asymmetric edge. An asymmetric edge may be defined by the length of the edge rounding W along the rake face and H along the clearance face, preferably wherein W/H>1. An example of such an asymmetric edge is disclosed in EP 0654317 A1.
[0014] The resulting radius of the edge rounding may be within the range of 10-70 μm, preferably within the range of 15-45 μm, such as 15-50 μm, more preferably within the range of 20-40 μm. Thus a range of edge radii may be obtained to optimize the cutting properties over the cutting edge.
[0015] The wedge angle may be formed on the cutting tool blank by grinding a sintered body, or formed during molding of a cutting tool green body before sintering. Thus the wedge angle having a variation along the cutting edge may be achieved in a cutting tool blank suitable for further processing.
[0016] The method may comprise a further step of applying a hard coating to the cutting tool blank after the step of removing material from the cutting edge. Thus the properties of the cutting tool having a desired variation of the edge rounding along the cutting edge may be further improved.
[0017] The disclosure further relates to a cutting tool including a cutting edge, wherein the cutting edge is defined by a cross-sectional wedge angle having a variation along the cutting edge and wherein the cutting edge has a corresponding variation of edge rounding along the cutting edge.
[0018] Thus, a desired variation of the edge rounding along the cutting edge may be achieved by simple, fast and reliable processing means as disclosed herein. The cutting tool may preferably be obtained by, or obtainable by, the method as disclosed herein.
[0019] The cutting tool may be a turning tool (including general turning, threading, boring, grooving, parting etc.) or a drilling tool, or a cutting insert for turning or drilling. During turning and drilling the tool is subjected to stable cutting with a minimum of vibrations. Therefore in these types of operations the cutting tool may advantageously utilize sharper (and thus more fragile) edges at various portions of the tool without jeopardizing the durability of the edge. During intermittent machining operations (e.g. milling), vibrations may arise which necessitates a stronger edge all over the cutting tool.
[0020] The cutting edge may be formed by a wedge-shaped cross-section with a wedge angle having a variation along the cutting edge, i.e. corresponding to a cross-sectional shape formed by two intersecting straight lines. Alternatively the wedge angle may be formed by a cross-sectional shape of any other kind, having a variation along the cutting edge. Then the shape forms the wedge angle having a variation along the cutting edge. The cross-sectional shape may be formed by two intersecting lines which are straight, convex, concave or combinations thereof, and defining the wedge angle at the point of intersection.
[0021] The wedge angle may be within the range of 60 to 100 degrees, preferably within the range of 70 to 90 degrees, along the cutting edge. Thereby a suitable range of edge radii may be achieved.
[0022] The variation of the wedge angle along the cutting edge may be within the range of 5-35 degrees, preferably within the range of 10-30 degrees, more preferably within the range of 15-25 degrees, or within the range of 10-20 degrees, along the cutting edge. Thereby a suitable range of edge radii may be achieved.
[0023] The variation of the wedge angle may be obtained by a variation of the clearance angle along the cutting edge. Thus the rake angle of the cutting tool may be held unchanged in order to maintain a desired cutting property of the cutting tool.
[0024] The variation of the wedge angle may preferably be continuous along the cutting edge. When applied to cutting tool inserts, the variation of the clearance angle, forming the wedge angle, may be limited to a portion of the tool (e.g. 1 mm) from the cutting edge, meaning not extending all the way down to the other face of the tool, thus providing a feature to fabricate cutting tools with cutting edges on both sides (e.g. negative inserts).
[0025] The cutting tool may have a nose and a leading edge and/or a trailing edge and the wedge angle may be smaller at the nose than at the leading edge and/or the trailing edge, whereby the radius of the edge rounding is smaller at the nose than at the leading edge and/or the trailing edge. Typically, the cutting properties at the nose region of the cutting tool differ from the cutting properties at the leading edge and/or a trailing edge, whereby it may be desirable to have a sharper edge at the nose region than at the leading and/or trailing edge.
[0026] The wedge angle may be gradually expanded from the tip of the nose towards the leading edge and/or trailing edge, whereby the edge radius is gradually increasing from the tip of the nose towards the leading edge and/or trailing edge.
[0027] The cutting tool may be a sintered cemented carbide body or a cubic boron nitride body.
[0028] The disclosure further relates to the use of a cutting tool as disclosed herein to machine stainless steel or titanium alloy. Stainless steel and titanium alloys are difficult to machine and it may be important to provide a cutting edge having a sharpness that is optimized to the local cutting properties along various portions of the cutting edge, e.g to have a sharper edge at the nose region of the cutting tool.
BRIEF DESCRIPTION OF DRAWINGS
[0029] FIG. 1 shows a cutting tool in top view, indicating a section II-II of the cutting edge.
[0030] FIG. 2 shows the cutting edge of the cutting tool in section II-II.
[0031] FIG. 3 shows a perspective view of the cutting tool, indicating a section II-II of the cutting edge.
[0032] FIG. 4 shows a detail of the cutting edge of the cutting tool in section II-II, with the edge rounding.
[0033] FIG. 5 shows measurements of the edge radius r β along the cutting edge of a reference cutting tool, and the corresponding wedge angle.
[0034] FIG. 6 shows measurements of the edge radius r β along the cutting edge of a cutting tool (variant A) having a variation of the wedge angle, and the corresponding wedge angle.
[0035] FIG. 7 shows measurements of the edge radius r β along the cutting edge of a cutting tool (variant B) having a variation of the wedge angle, and the corresponding wedge angle.
[0036] FIG. 8 shows measurements of the edge radius r β along the cutting edge of a cutting tool (variant C) having a variation of the wedge angle, and the corresponding wedge angle.
[0037] FIG. 9 shows examples of resulting edge radius r β depending on wedge angle β and material removal rate Q per unit edge length per unit of time.
DEFINITIONS
[0038] Wedge angle β is defined as the angle between a rake surface and a flank surface in a cross-section of the cutting edge.
DETAILED DESCRIPTION
[0039] In FIGS. 1 and 3 a cutting tool in the form of a cutting insert 1 is shown in a top view and a perspective view respectively. The cutting insert comprises a body 2 of a hard material, e.g. cemented carbide (WC) or cubic boron nitride. The cutting insert is provided with a rake face 3 , facing the material to be machined during operation. The cutting insert further comprises one or more flank (or clearance) faces 4 . In the example shown the cutting insert is an indexed cutting insert, having four indexable cutting positions, and thus four similar flank faces. In the interception between the rake and flank faces, a cutting edge 5 is defined, in this case continuously encircling the cutting insert. Depending on the orientation of the cutting insert during machining operation, different portions of the cutting edge define a leading edge, a trailing edge and a nose region. The leading edge 6 is the edge meeting the material to be machined. The trailing edge 7 may or may not be in contact with the material to be machined, depending on the configuration of the cutting insert and machining parameters. Between the leading edge and the trailing edge, a nose region 8 is defined, e.g. having a nose radius.
[0040] FIG. 2 shows a section of the cutting insert in FIGS. 1 and 3 , in the plane indicated by II-II, showing the rake face 3 , the clearance face 4 and the cutting edge 5 .
[0041] In FIG. 4 , a detailed view of the cutting edge 5 in FIG. 2 is shown, with the rake face 3 and the clearance face 4 . The wedge angle β and the clearance angleγ is shown, as well as the edge rounding having an edge radius r β . The theoretical shape of the cutting edge before removal of material from the cutting edge, is indicated by dotted lines.
[0042] In the following, examples of cutting inserts for turning operations will be described in more detail, however similar considerations apply for e.g. drilling tools.
[0043] It is important to note that the amount of material being cut by the cutting tool per unit length of the cutting edge during machining operation differs along the cutting edge. In turning for example, the amount of material being cut at the leading edge is larger per unit length of the cutting edge at the leading edge than at the nose region. This is because the cutting insert is oriented such that the leading edge is more or less aligned with the feed direction of the material to be machined. The cutting edge at the nose region on the other hand is not aligned with the feed direction of the material to be machined. Therefore the amount of material that is being cut by the cutting insert differs between the leading edge and the nose region. At the leading edge the amount of material being cut per unit length of the cutting edge is larger than at the nose region. Therefore, a stronger edge is preferred at the leading edge. It is also desired to have a larger wedge angle at the leading edge to improve dissipation of thermal energy in the cutting insert during machining Because the uncut chip thickness of the edge in the nose region is thinner, a sharper edge is preferred in this region.
[0044] Thus the cutting insert is provided with a continuous variation of the wedge angle along the cutting edge, such that the wedge angle is larger at the leading edge and smaller in the nose region. Therefore the cutting insert is configured such that the wedge angle is smaller at the nose than at the leading edge and/or the trailing edge. The wedge angle is gradually expanded from the tip of the nose towards the leading edge and/or trailing edge, whereby the edge radius is gradually increasing from the tip of the nose towards the leading edge and/or trailing edge. The wedge angle is formed by a wedge-shaped cross-section of the cutting edge. The variation of the wedge angle is obtained by a variation of the clearance angle (γ in FIG. 4 ) along the cutting edge.
[0045] The wedge angle is within the range of 60 to 100 degrees, preferably within the range of 70 to 90 degrees, along the cutting edge. The variation of the wedge angle along the cutting edge is within the range of 5-35 degrees, preferably within the range of 10-30 degrees, more preferably within the range of 15-25 degrees, or within the range of 10-20 degrees, along the cutting edge.
[0046] The variation of the wedge angle along the cutting edge is preferably formed during molding of a green body of the cutting insert, i.e. before sintering of the cutting insert. Alternatively the variation of the wedge angle along the cutting edge may be formed by grinding of the periphery, forming the cutting edge, of the cutting insert after sintering.
[0047] Material is removed from the cutting edge of the sintered cutting tool by means of e.g. wet blasting, dry blasting, brushing, electro discharge machining or laser processing. Material is removed with a constant material removal rate per length unit of the edge.
[0048] Due to the combination of the variation of the wedge angle along the cutting edge, and the removal of material along the cutting edge with a constant material removal rate per length unit of the edge, the radius of the edge rounding is smaller at the nose than at the leading edge and/or the trailing edge.
[0049] Thus a cutting insert is provided with a sharper edge at the nose region and a stronger edge at the leading edge.
EXAMPLES
[0050] Four set of cutting inserts are disclosed. The wedge angles in all four sets were created by keeping the rake face of CNMG-120408-MM inserts unchanged and modifying the clearance face by means of periphery grinding. The leading edge of the cutting insert has a wedge angle of 90° in all variants. Starting from the beginning of the nose on the leading edge, the wedge angle decreases to a minimum of 80°, 70° and 60° at the center of the nose in variants A, B and C, respectively, after which it increases back to 90° at the end of the nose edge, where the nose meets the trailing edge, in all variants. A reference insert is included in the set of cutting inserts where the wedge angle is 90° and is constant along the edge. The wedge angles (and clearance angles) of these different sets of cutting tools are shown in Table 1.
[0000]
TABLE 1
Examples of four different sets of cutting inserts.
Leading edge wedge
Nose edge minimum wedge
angle/clearance angle
angle/clearance angle
Reference
90°/0°
90°/0°
Variant A
90°/0°
80°/10°
Variant B
90°/0°
70°/20°
Variant C
90°/0°
60°/30°
[0051] Inserts were blasted in a wet blasting machine by Alox (aluminum oxide mesh size) 220 with 2.5 bar blasting pressure in a single process. The target cutting edge radius for a 90 degrees wedge angle was 55 μm. Subsequent to the blasting process the edge radius was measured along the leading edge and on the nose edge. The wedge angle was also measured along this length of the cutting edge.
[0052] In FIGS. 5-8 the cutting edge radius (a and b) and the wedge angle (c and d) measured along this length of the cutting edge is shown for the reference insert ( FIG. 5 ) and the different variants A ( FIG. 6 ), B ( FIG. 7 ) and C ( FIG. 8 ). Each data point represents a cross sectional measurement on the cutting edge. The measurements are shown for the leading edge (a and c) and for the nose section of the edge (b and d). There are 24 cross sections on the leading edge and 24 on the nose section of the edge. The average distance between two measurement points is 70 μm.
[0053] As can be seen in FIGS. 5-8 , there is a strong correlation between the wedge angle and edge radius at different locations along the cutting edge. As the wedge angle decreases in the nose region (see FIGS. 5-8 d ) the cutting edge radius also decreases (see FIGS. 5-8 b ) and as a result a variable edge micro-geometry will be created in all three variants. A 30% reduction in the wedge angle (from 90° to 60°), would lead to almost 35% reduction in edge radius value.
[0054] In FIG. 9 the effect of varying wedge angle and material removal rate per length unit of the edge is shown. The material removal rate is defined as a removal of a volume of material per length unit of the edge and per unit of time. The graph shows the resulting edge radius r β depending on wedge angle β for seven different material removal rates Q, from 50 μm 2 per unit edge length per unit of time, to 500 m 2 per unit edge length per unit of time. It is clear from the graph that the resulting edge radius r β decreases with decreasing wedge angle β. The material removal rate is preferably within the range of 100-600 μm 2 per length unit of the edge per unit of time, or within the range of 200-500 μm 2 per length unit of the edge per unit of time, or within the range of 300-400 μm 2 per length unit of the edge per unit of time.
[0055] Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.
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The disclosure relates to a method of manufacturing a cutting tool including the steps of: providing a cutting tool blank including a cutting edge, defined by a cross-sectional wedge angle (β). The wedge angle has a variation along the cutting edge, and material is removed from the cutting edge with a constant material removal rate per length unit of the edge, such as to form a corresponding variation of edge rounding along the cutting edge. The disclosure further relates to a cutting tool including the cutting edge defined by the cross-sectional wedge angle having a variation along the cutting edge and wherein the cutting edge has a corresponding variation of edge rounding along the cutting edge.
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BACKGROUND INFORMATION
1. Field of the Invention
This invention relates to acrylates in which a large percentage of hydrogen atoms have been replaced by halogens and to polymers that include mer units derived from such halogenated acrylates.
2. Background of the Invention
Optically transparent polymers, especially those used for telecommunication applications, must have low absorptive loss in the infrared wavelengths, typically 1260-1360 nm and 1480-1580 nm. However, because these wavelengths are close to overtones of carbon-hydrogen bond vibration frequencies, minimization of the number of carbon-hydrogen bonds is desirable. While some organic compounds with few C--H bonds are known, additional considerations of optical transparency, ease of polymerization, refractive index, chemical and mechanical stability, and the need to compete on a cost basis with glass prevent many such compounds from widespread use in polymeric optical devices.
U.S. Pat. Nos. 3,668,233, 3,981,928, and 4,010,212 describe acrylic acid esters (i.e., acrylates), prepared from esterification of acrylic acid with perfluoro-tertiary alkyl alcohols such as perfluoro-t-butyl alcohol, that can be used as inert heat exchange fluids and as homopolymeric water- and/or oil-repellent surface coatings.
European Patent Application No. 282,019 describes highly fluorinated, transparent acrylates specifically tailored for optical articles. These materials are prepared from cyclic or bicyclic alcohols containing few or no carbon-hydrogen bonds.
U.S. Pat. No. 3,544,535 describes the preparation and polymerization of 2-(pentafluorophenyl)hexafluoroisopropyl acrylate. Optical properties of the polymer are not described.
U.S. Pat. Nos. 3,520,863 and 3,723,507 describe a number of perfluorocycloalkyl acrylates and polymers thereof Use of tertiary alcohols is not reported, and optical properties of the polymers are not discussed.
U.S. Pat. No. 5,045,397 describes the preparation and use of certain adhesives to be used in optical systems. A polymeric adhesive of a specified refractive index is prepared by copolymerization of specified monomers of known refractive indices. While some lightly fluorinated monomers are described, highly fluorinated monomers are not disclosed.
U.S. Pat. No. 5,223,593 describes acrylate monomers and their (co)polymers designed to have low C--H bond density relative to poly(methylmethacrylate) so as to reduce vibrational band intensities in plastic optical fiber cores. Absorbance at 600-1200 nm was reduced, but absorbance at higher frequencies is not reported. The described acrylates were prepared from highly fluorinated primary alcohols.
U.S. Pat. No. 5,093,888 describes a polymeric optical device (specifically, an injection-molded Y-shaped splitter waveguide) that uses an amorphous polymeric adhesive that includes 2,2,2-trifluoroethyl methacrylate having a refractive index of 1.418 to hold optical fibers in a polytetrafluoro-ethylene spacer containing a fluorinated polyetheretherketone core.
U.S. Pat. No. 5,311,604 describes a method of manufacturing a polymeric optical interconnect. Useful polymers are said to be those transparent to the wavelength of light to be utilized. Listed examples include poly(methylmethacrylate) ("PMMA"), polycarbonates, polyurethanes, polystyrenes, and polyolefins. In one example, a "copolymer of deuterated PMMA-d8 (sic) and tetrafluoropropyl methacrylate" is used to adhere optical fibers to a molded PMMA device.
U.S. Pat. No. 5,343,544 describes a polymeric optical interconnect. The device includes polymeric substrate and covering members that can be fabricated from, for example, a combination of fluorinated and non-fluorinated photopolymerizable (meth)acrylate and di(meth)acrylate monomers. The same combination of monomers is said to be useful for sealing optical fibers in the device. Substitution of fluorines for hydrogen atoms in the polymer is said to be capable of reducing the refractive index of the polymer and to reduce losses in near infrared wavelengths, but no example of a haloacrylate-only system and no indication of the degree to which loss or refractive index can be controlled are given. Copolymerization of two or more monomers is said to be able to provide a copolymer having a tailored refractive index.
Devices used in telecommunication applications (such as those described in '604 and '544, above) preferably meet certain standards for performance, durability, and the like. The standards most commonly referred to in discussing such devices are the so-called "Bellcore Specifications". Requirements for fiber optic branching components include parameters for optical loss (i.e., loss that is in excess over that which is inherent in the device), useable wavelength ranges, resistance to performance variability caused by temperature and humidity, optical cross talk, water immersion, flammability, etc. All such parameters can depend, at least in part, on the materials used to make the device. For example, materials must have very low absorptive losses in the wavelength regions of 1260 to 1360 nm (nominally 1310 nm) and from 1480 to 1580 nm (nominally 1550 nm), over which ranges low losses must be maintained under extreme temperature and humidity conditions. For a 1×2 splitter, the inherent loss is calculated to be 3.01 decibels (dB), where a decibel is defined as -10 log(I o /I i ) in which I o is the intensity of the output and I is the intensity of the input. Maximum allowable excess loss in a 1×2 splitter is quantified as, e.g., no more than 0.25 dB per fiber plus no more than 0.5 dB per waveguide junction connecting an input fiber to an output fiber.
Presently available materials other than glass have not proven to be able to meet all, or even most, of these rigid requirements.
SUMMARY OF THE INVENTION
Briefly, the present invention provides halogenated acrylates having the general formula ##STR1## wherein
M is H, CH 3 , F, Cl, Br, I, or CF 3 ; preferably M is H, F, or Cl; most preferably M is H because of availability, reactivity, and thermal stability;
A is oxygen or sulfur; and
Z can be a group having a maximum of 150 carbon atoms and can be ##STR2## in which each R 1 independently is F, Cl, or Br; ##STR3## in which each R 2 independently can be
(a) a perfluorinated, perchlorinated, or per(chlorofluoro)
(i) C 1 -C 20 aliphatic group,
(ii) C 3 -C 20 cycloaliphatic group,
(iii) C 6 -C 20 aryl group,
(iv) C 7 -C 20 aralkyl group, and
(v) C 7 -C 20 alkaryl group,
(b) F, Cl, Br, I, Q (defined below), R 4 COO--, R 4 O--, --COOR 4 , --OSO 2 R 4 , or --SO 2 OR 4 , wherein R 4 is any group from (a)(i), (a)(ii), (a)(iii), (a)(iv), and (a)(v),
or any two adjacent R 2 groups together can form a perfluorinated, perchlorinated, or per(chlorofluoro) cycloaliphatic or aromatic ring moiety in which n fluoro or chloro groups optionally can be replaced by R 2 groups where n is a whole number in the range of 0 to 25, and R 2 is as defined above, wherein Q is ##STR4## in which A is as defined as above, with the proviso that all R 2 groups in the molecule can be the same only when R 2 is not Cl, F, Br or I, and each R 3 independently can be
(a) a perfluorinated, perchlorinated, or per(chlorofluoro)
(i) C 1 -C 20 aliphatic group,
(ii) C 3 -C 20 cycloaliphatic group,
(iii) C 6 -C 20 aryl group,
(iv) C 7 -C 20 aralkyl group, and
(v) C 7 -C 20 alkaryl group,
(b) F, Cl, Br, I, Q (defined above), R 4 COO--, R 4 O--, --COOR 4 , --OSO 2 R 4 , or
--SO 2 OR 4 , wherein R 4 is any group from (a)(i), (a)(ii), (a)(iii), (a)(iv), and (a)(v),
or any two adjacent R 3 groups together can form a perfluorinated, perchlorinated, or per(chlorofluoro) cycloaliphatic or aromatic ring moiety in which n fluoro or chloro groups optionally can be replaced by n R 3 groups where n is a whole number in the range of 0 to 25, and R 3 is as defined above;
(3) --(R f ) 2 E in which
both R f groups together can be part of a perfluorinated, perchlorinated, or per(chlorofluoro) cycloaliphatic ring group or each independently can be a perfluorinated, perchlorinated, or per(chlorofluoro)
(a) C 1 -C 20 aliphatic groups,
(b) C 3 -C 20 cycloaliphatic groups,
(c) C 6 -C 20 aryl groups,
(d) C 7 -C 20 aralkyl groups, or
(e) C 7 -C 20 alkaryl groups,
(f) C 4 -C 20 heteroaryl groups,
(g) C 4 -C 20 heteroaralkyl groups,
(h) C 4 -C 20 heteroalkaryl groups,
wherein the heteroatoms can be one or more of O, N, and S atoms, with the proviso that at least one R f group includes one or more of the following:
(1) at least one straight-chain C 4 -C 20 aliphatic or C 4 -C 20 cycloaliphatic group,
(2) at least one ether oxygen atom, and
(3) at least one branched C 3 -C 20 aliphatic group, and E can be R f , ##STR5##
wherein R 1 , R 2 , R f , and Q are defined as above; or
(4) --CR f (E) 2 ,
wherein each E independently is as defined above, and R f is as defined above.
In another aspect, the present invention provides a polymer that includes at least one mer unit derived from the above-described haloacrylates as well as optical devices and optical materials made from such a polymer.
In yet another aspect, this invention provides di- and tri-functional acrylates as crosslinking agents with low hydrogen content, usually no more than the required three H atoms around each acrylate group.
In yet another aspect, this invention provides ether-containing perhalo-, preferably perfluoro- and perchlorofluoro ketones as intermediates to low H-content acrylates. Preferred compounds include 1,2-dichloroperfluoroethyl ether and 1,1,2-trichloroperfluoroethyl ether derivatives which can be prepared by the direct fluorination of a 1,1-dichloroethyl ether and 1,1,1-trichloroethyl ether, respectively.
In yet a further aspect, this invention provides 1,2-dichloroperfluoro/per(chlorofluoro) ethers useful in the synthesis of the above acrylates and also useful as precursors to perfluorovinyl ether monomers optionally substituted by functional groups. Preferred perfluorinated ketones have the structure R 5 f OCF 2 COCF 3 , R 5 f OCF 2 COCF 2 Cl, and R 5 f OCF 2 COCF 2 OR 5 f , wherein R 5 f is a linear perfluoroalkyl or perfluorooxyalkyl group having from two to twenty carbon atoms.
In this application, the following definitions apply unless a contrary intention is explicitly indicated:
(a) "group"0 or "compound" or "monomer" or "polymer" or "mer unit" means a chemical species that allows for substitution by conventional substituents that do not interfere with the desired product such as, for example, linear or branched alkyl or haloalkyl groups;
(b) "optical coupler" or "interconnect" means a device that joins one or more input optical fibers to one or more output optical fibers and includes devices such as splitters and combiners;
(c) "acrylate" includes corresponding "methacrylate" and other 2-substituted acrylates throughout this application; and
(d) subscript " f " refers to a perhalogenated group.
The halogenated acrylates of the present invention have relatively few C--H bonds, usually no more than three (i.e., those around the acrylate unsaturation) or no more than five (around methacrylate unsaturation). This dearth of hydrogens means that these compounds have very little absorption in the infrared wavelengths of interest, i.e., 1260-1360 nm and 1480-1580 nm. Because these materials can be used in optical applications, particularly devices that guide light such as waveguides and optical interconnects, minimizing loss of signal due to absorption by the material of which the device is made is very important and desirable.
Despite the fact that the acrylates of the present invention are highly halogenated, they are relatively easy to polymerize, are optically clear, have low optical loss, are liquids or solids with relatively low melting points or dissolve sufficiently in lower-melting comonomers, provide amorphous polymers with good thermal stability and high molecular weights, and provide polymers (typically copolymers) having indices of refraction that effectively match those of glass optical fibers. These characteristics make them excellent candidates for use as materials in polymeric optical devices, especially waveguides and optical couplers.
Presently available optical devices made from glass are manufactured in one-at-a-time, handwork operations that are very labor intensive and prone to low productivity. Polymers of the invention can be processed automatically by known polymer processing methods into optical devices that are physically robust and are substantially identical, leading to significant improvements in product reliability and economics. Polymeric optical devices of the present invention can be mass produced and can be handled under severe field conditions without undue damage and/or loss of properties.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a comparison of absorption vs. wavelength plots of a polymer derived from one embodiment of the halogenated acrylates of the present invention with two comparative halogenated polyacrylates.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Halogenated acrylates of the present invention are useful for various optical applications. They display several highly desirable characteristics including ease of polymerization, optical clarity, favorable melting points, and polymers therefrom exhibit very little absorption in critical infrared regions (i.e., 1260-1360 nm and 1480-1580 nm), thus minimizing optical loss due to absorption. When halogenated acrylates of the present invention are polymerized, or when two or more are copolymerized, the resulting polyacrylate is amorphous, has good thermal stability, has relatively high molecular weight, and can have an index of refraction that effectively matches that of a glass optical fiber. Further, halogenated acrylates of the invention can be copolymerized to prepare copolymers having specifically desired physical properties, such as refractive index (n.sub.λ, glass transition temperature (Tg), optical absorption, etc. In spite of published theories of predicting such properties based on additivity considerations (e.g., the Fox equation for Tg), we have found that certain combinations of monomers, particularly those having high molecular bulk, give copolymers having unpredicted refractive indices, and that physical properties and chemical reactivities of these highly halogenated monomers cannot be predicted a priori. Further, we have found that synthesis and measurement are required to determine the exact refractive index and reactivity of these highly halogenated monomers, and that copolymers must be prepared in order to determine their precise refractive index and melting point; calculations and predictions are insufficient. Table 1, below, shows the disparity between calculated and observed refractive indices for a number of homopolymers of the invention.
Halogenated acrylates of the present invention have the general formula ##STR6## wherein M, A and Z are as defined above.
The portion of the molecule other than the Z moiety defines a typical acrylate when A is oxygen and a thioacrylate when A is sulfur. As those skilled in the art of polymer science are well aware, acrylates are a broad class of polymerizable materials, the chemistry of which is well defined.
Although M typically is H, other substituents such as CH 3 , F, Cl, Br, I, or CF 3 can be used in place of hydrogen. However, any such substitution should be done while keeping in mind the desired performance characteristic(s) of the material (e.g., polymer index of refraction, ease of polymerization, liquidity at the temperature(s) of use, very little absorption in the critical infrared regions, monomer availability, and cost, etc.).
Many acrylates meet several of the aforementioned criteria regarding acceptable materials. For example, acrylates have relatively low melting points and can be polymerized to amorphous polymers with high molecular weights. However, heretofore available acrylates have not been able to meet those criteria relating to optical performance. Specifically, such acrylates have had unacceptably high absorption in the aforementioned infrared wavelength regions. In contrast, halogenated acrylates of the present invention have acceptably low absorption in these wavelength regions.
In the general formula set forth above, A can be either oxygen or sulfur. (Although the term "acrylate" normally would include only those compounds where A is oxygen, for present purposes, the term includes those compounds where A is sulfur.) For reasons of availability of starting materials, hydrolytic stability, and potential odors, those compounds where A is sulfur are not as preferred as those where A is oxygen.
The Z moiety in the above formula serves at least two important functions. First, it assists in tailoring the index of refraction of the polymerized halogenated acrylate. Because the index of refraction of optical fiber cores and cladding layers generally fall in the range of 1.44 to 1.46, this is a desirable index of refraction range for optical materials of the invention. Preferably, homopolymers prepared from the halogenated acrylates of the present invention have an index of refraction of between about 1.36 and about 1.56. Further, acrylate monomers can be mixed to provide copolymers having an index of refraction in the desired range. Since the index of refraction of most glass used in optical fiber cores is approximately 1.457, a preferred index of refraction of a copolymer of the invention can be approximately 1.450. It is to be appreciated that in an optical device the index of refraction of a core desirably is slightly higher than the clad, and the core index of refraction desirably matches the index of refraction of an optical fiber core, which fiber is connected to the device. Typically, the index of refraction of the clad in a device can be slightly less than that of the core (the difference preferably is about 0.007).
Second, the bulk of the Z moiety assists in keeping low the weight percentage of hydrogen in the halogenated acrylates of the present invention. To reach acceptably low absorption in the infrared wavelength regions of interest (i.e., those wavelengths where overtones of C--H bond vibration frequencies absorb), keeping the weight percentage of hydrogen in the compound as low as possible is desirable. An empirical rule regarding the relationship between molar volume and absorption loss at 1480 nm has been developed through experience: to keep absorption loss less than 0.1 dB/cm (at 1480 nm), a haloacrylate of the invention wherein A is O and M is H desirably has a molar volume of at least 150 mL/mole, more preferably at least 200 mL/mole, and even more preferably at least 250 mL/mole. The corresponding halomethacrylates wherein A is O and M is CH 3 require higher molar volumes to meet the 0.1 dB/cm (at 1480 nm) absorption loss criterion. To assist in meeting this target molar volume, Z serves the important function of increasing the molecular volume without adding hydrogen atoms to the halogenated acrylate of the present invention so that the effect of the hydrogen atoms surrounding the double bond is minimized. Copolymers of halogenated acrylates where one or more of the monomers includes a relatively small Z group and one or more monomers includes a relatively large Z group, such that the overall molar volume of the copolymer is at least 150 mL/mole, also are within the scope of the present invention.
Finally, the Z group influences the chemical stability and melting point of the monomer and resulting (co)polymer(s). In particular, we have found that any one of three types of substituents on the ester portion of the acrylate are preferred: inclusion of an ether oxygen in an aliphatic or aromatic group; mixtures of positional isomers of aromatic substituents; and branched aliphatic moieties; as well as combinations thereof As mentioned previously, Z can be one of four types of groups. First, Z can have the general formula --C(R f ) 2 E, wherein each R f group and E are as defined above.
As to each R f , examples of potentially useful C 1 -C 20 acyclic aliphatic groups include methyl, methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, methoxyethoxymethyl (i.e., CF 3 OCF 2 CF 2 OCF 2 ), methoxypropoxymethyl, methoxyethoxyethoxymethyl, ethoxyethoxymethyl, ethoxyethyl, and methoxyethyl groups. For each alkyl group named having more than two carbon atoms, isomers thereof, particularly branched isomers, are included in this definition. Further, all alkyl groups are fluoroalkyl, chloroalkyl, or fluorochloroalkyl groups; that is, all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, or combinations thereof
Examples of potentially useful R f groups comprising C 3 -C 20 cycloaliphatic groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo{2.2.1}hexyl, bicyclo{2.2.2}octyl, bicyclo{3.2.2}nonyl, and bicyclo{4.4.0}decyl. Any of the cycloaliphatic groups can include C 1 -C 10 straight-chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk considerations. As noted, all hydrogen atoms of the cycloaliphatic groups are to be replaced by fluorine atoms, chlorine atoms, or combinations thereof
Examples of R f groups as potentially useful C 6 -C 20 aryl groups include phenyl, naphthyl, indenyl, biphenyl, anthracyl, phenanthryl, and fluorenyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.
Examples of R f groups as potentially useful C 7 -C 20 alkaryl groups include methylphenyl, ethylphenyl, methylnaphthyl, dimethylphenyl, indanyl, and butylphenyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof
Examples of R f groups as potentially useful C 7 -C 20 aralkyl groups include phenethyl and benzyl groups, wherein all hydrogen atoms have been replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof
Examples of potentially useful R f groups comprising C 4 -C 20 heteroaryl, heteroaralkyl and heteroalkaryl groups include any cyclic aromatics comprising at least one oxygen, nitrogen or sulfur atom in the ring, including those having C 1 -C 10 straight-chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk considerations. Useful heteroaromatics include furan, thiophene, pyrrole, 1,2- and 1,4-pyran, 1,2- and 1,4-thiopyran, pyridine, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole, 1,2,3- and 1,2,4-triazole, tetrazole, pyridazine, pyrimidine, pyrazine, 1,4-dioxin, 1,4-dithiin, 1,2-, 1,3-, and 1, 4-oxathiin, 1,2-, 1,3-, and 1,4-oxazine, and 1,2-, 1,3-, and 1,4-thiazine. It is to be appreciated that all hydrogen atoms of each of the above-named heteroaryl ring systems and their alkyl-substituted analogs are to replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof In addition to the single-ring heteroaryl, heteroaralkyl and heteroalkaryl groups, R f groups can comprise analogous fused-ring heteroaromatic compounds including benzofuran, thionaphthene, indole, isothionaphthene, isobenzofuran, isoindole, 1,2- and 1,4-benzopyran, 1,2- and 1,4-benzothiopyran, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, phthalazine, benzoxazole, benzothiazole, benzimidazole, benzpyrazole, benzotriazole, and numerous fused ring groups comprising three or more rings comprising at least one N-, O-, or S-atom, including any of these having C 1 -C 10 straight-chain or branched aliphatic carbon substituents, as well as above-named acylic aliphatic groups, at any position thereof, consistent with steric bulk considerations. It is to be appreciated that all hydrogen atoms of each of the above-named heteroaryl ring systems and their alkyl-substituted analogs are to replaced by fluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.
Some R f groups that can be particularly useful for certain applications include methyl, chloromethyl, ethoxymethyl, (2-chloroethoxy)methyl, trichloroethoxymethyl, hexyl, cyclohexyl, and butoxymethyl.
R f groups including branched aliphatic or alkyl groups may be preferred when mixtures of branched isomers or stereoisomers can be obtained that result in lowering of the haloacrylate melting point to provide ease of handling of the monomers.
E represents one of four substituents. Specifically, E can be R f , ##STR7## wherein R 1 , R 2 , R f , and Q are defined as above. In a preferred embodiment, each R 1 or R 2 is F.
Z also can have any of the formulae ##STR8## in which each R 1 is defined as above. Where Z has this formula, preferred compounds include those where each R 1 is either F or Cl.
Third, Z also can have the formula ##STR9##
wherein each R 2 is as previously defined.
In a preferred embodiment, at least one R 2 is F, OC 6 F 5 , SC 6 F 4 CF 3 , OC(O)C 6 F 5 , or OSO 2 C 4 F 9 .
Fourth, Z can have the formula CR f (E) 2 wherein each E and R f are as previously defined.
Some preferred halogenated acrylates of the present invention having homopolymers with refractive indices greater than or equal to 1.457 (i.e., "high index materials") are represented by the following formulae: ##STR10##
Some preferred halogenated acrylates of the present invention having homopolymers with refractive indices less than 1.457 (i.e., "low index materials") are represented by the following formulae: ##STR11##
In addition to the acrylate monomers shown above, the following tertiary carbinols can easily be converted into the corresponding acrylates, the homopolymers of which are predicted to be low index materials: ##STR12## In the above formulae, ##STR13## represents a cyclohexyl ring in which all hydrogen atoms are replaced by fluorine atoms (i.e., a perfluorocyclohexyl group).
Many preferred halogenated acrylate monomers of the invention include at least one perfluoroether moiety. An ether linkage allows ready variation of the structure of a starting material to be fluorinated and of the fluorinated product. It has been found that the perfluoroether group provides favorable physical properties, such as low melting point or liquidity at 23° C., while allowing control of the refractive index of the corresponding homopolymer and related copolymers by control of structure and substituents.
Homopolymers prepared from these acrylates have characteristic indices of refraction. Accordingly, one wishing to use one or more of these compounds (or any of the halogenated acrylates of the present invention) can choose as halogenated acrylate the homopolymer of which has an index of refraction that matches that which is desired or can choose two or more of these acrylate monomers and copolymerize them so as to provide a polymer that has the desired index of refraction.
FIG. 1 shows absorption versus wavelength plots for three halogenated polyacrylates: poly(perfluorophenylacrylate) (PFPA) (comparative tracing C), poly(perfluorophenylthioacrylate) (PFPTA)(comparative tracing B), and compound VIII of the present invention (tracing A), above. PFPA is commercially available from Polysciences, Inc. (Warrington, Pa.) whereas PFPTA and compound VIII can be prepared by, for example, reaction of acryloyl chloride with pentafluorothiophenol or 2-(pentafluorophenyl)-2-perfluorooctanol, respectively. The aforementioned wavelength regions of interest as well as the acceptable absorption limits in those wavelength regions (imposed by the aforementioned Bellcore specifications) are represented by boxes D and E. As is apparent, all three of the polyacrylates have acceptable (i.e., very low) absorption in the 1310 nm region, but only compound VIII has a completely acceptable absorption profile in the 1550 nm region.
Halogenated acrylates of the present invention can be prepared by reacting an acrylic acid derivative such as acryloyl chloride or acrylic anhydride with a perhalogenated alcohol, alkoxide, or alkoxy-substituted alcohol in the presence of an organic base (e.g., a tertiary amine). Using 2-acryloyloxyheptafluoronaphthalene (compound V) as an example, one can react heptafluoro-2-naphthol with acryloyl chloride and triethylamine in an appropriate solvent such as acetonitrile. (See Example 1, below, for more details.) Choice of solvent(s), temperature, pressure, and other reaction variables are within the level of skill possessed by the ordinarily skilled artisan discussed below.
Perhalogenated alkoxides may be prepared from the corresponding perhalogenated alcohols by treatment with base, or by treatment of a perhalogenated carbonyl compound with an alkali metal fluoride (e.g. KF) or perhalogenated carbanion sources such as organometallic reagents (e.g., organo lithiums or Grignard reagents). Perhalogenated alcohols or carbonyl compounds may be prepared by the following methods:
1) Addition of a perhalogenated organometallic compound to a perhalogenated ketone (e.g. C 6 F 5 MgCl+R 6 f COR 6 f →→R 6 f R 6 f C 6 F 5 COH, where each R 6 f group independently can be a perhalogenated straight-chain, branched, or cyclic aliphatic group containing from 1 to 20 carbon atoms and may contain up to 5 ether oxygen atoms). The perhalogenated ketone may be prepared by similar addition of a perhalogenated organometallic compound to a perhalogenated acid fluoride, or may be prepared by direct fluorination of an ester of a secondary alcohol followed by cleavage of the resulting perhalogenated secondary ester.
2) Displacement of a fluorine atom by a hydroxy (or latent hydroxy) on a perhalogenated arene compound.
A preferred class of perhalogenated alcohols or ketones is ether-containing perhalogenated alcohols or ketones. These may be prepared by direct fluorination of an ether-containing precursor ester of a primary or secondary alcohol. For example, they may be prepared by reaction of an alcohol and either propylene glycol (Scheme 1) or epichlorohydrin (Scheme 2) to produce a secondary alcohol, which may then be acylated, fluorinated by direct fluorination, and the resulting perhalogenated ester cleaved by any of the methods described in U.S. Pat. No. 5,466,877, incorporated herein by reference. Perfluorinated ketones of the structure R 7 f OCF 2 COCF 3 , R 7 f OCFCOCF 2 Cl, and R 7 f OCF 2 COCF 2 OR 7 f are novel where R 7 f is a linear perfluoroalkyl or perfluorooxyalkyl group having from two to twenty carbon atoms. These compounds are especially useful in preparing the acrylates of this invention to impart a low Tg and high molar volumes. ##STR14## or ##STR15##
wherein R 7 is a linear alkyl or oxyalkyl group which can be terminated by any of --CH 3 , --CH(CH 3 ) 2 , --C(CH 3 ) 3 , --OCH 3 --OCH(CH 3 ) 2 , or --OC(CH 3 ) 3 , wherein each R 7 f is the perhalogenated analog of R 7 , R 7 and R 7 f groups having from 1 to 20 carbon atoms, and Y can be Cl, OR 7 and Y f can be Cl or OR 7 f . Preferred classes of the perfluorinated ether ketone intermediates are those mono- and diethers in which R 7 f is a perfluoro or per(chlorofluoro)alkyl group of 2-12 carbons and containing up to 5 ether oxygens. Similarly, direct fluorination of the di- or trimesters can lead to di- or tri-ketones.
Halogenated acrylates containing bromine or chlorine in addition to fluorine are useful in increasing the refractive index of the corresponding homo-and copolymers. Chlorofluoroalkyl acrylates may be prepared by the previously described methods from either chlorofluoroketones or chlorofluoroacyl halides. See Example 24. Higher amounts of chlorine in the acrylate are especially useful in raising the refractive index. Surprisingly, it has been found that 1,1-dichloroethoxy ethers and 1,1,1-trichloroethoxy ethers, when subjected to direct fluorination, undergo a rearrangement to produce 1,2-dichloro-perfluoroethoxy ethers and 1,1,2-trichloroperfluoroethoxy ethers respectively. See Examples 11 and 21, and Table 4, compounds 4-2, 4-3, and 4-22. This rearrangement is illustrated in one embodiment, as follows:
Cl.sub.2 CHCH.sub.2 OR.sup.8 →ClCF.sub.2 CFClOR.sup.8.sub.f,
and
Cl.sub.3 CCH.sub.2 OR.sup.8 →Cl.sub.2 CFCFClOR.sup.8.sub.f,
wherein R 8 is a C 1 -C 20 alkyl- or acyl-containing group optionally containing up to 5 ether oxygen atoms and R 8 f is the corresponding perhaloalkyl or perhaloacyl-containing group, optionally containing up to 5 ether oxygen atoms. Perhaloalkyl or perhaloacyl-containing esters can be cleaved to produce perhaloketones and perhaloacid fluorides as previously described.
Preferred compounds have the formulae ClCF 2 CFClOR 8 f and Cl 2 CFCFClOR 8 f and are made by direct fluorination of compounds of the formulae Cl 2 CHCH 2 OR 8 and Cl 3 CCH 2 OR 8 , respectively, wherein R 8 can be a C 1 -C 20 alkyl-or acyl-group optionally containing up to 5 ether oxygen atoms and R 8 f can be the corresponding perfluoroalkyl or perfluoroacyl-containing group, optionally containing up to 5 ether oxygen atoms.
The rearrangement is surprising in view of the known instability of α-chloro ethers (see Adcock, et al., U.S. Govt. Report #AD139958 (1984)). These 1,2-dichloroperfluoroethyl ethers and 1,1,2-trichloroperfluoroethyl ethers are useful as solvents and in the preparation of perfluoro- and chloroperfluorovinyl ethers (see U.S. Pat. No. 5,350,497). A preferred subset of these 1,2-dichloro perfluoro/per(chlorofluoro) ethers is that in which the R 8 f group contains 1 to 12 carbon atoms and up to 5 ether oxygen atoms. Another preferred subset is that in which the preferred R 8 f group also contains a COF or SO 2 F group.
Refractive index and optical absorbance data for several of the compounds whose structures are shown above are given in Table 1, below.
TABLE 1__________________________________________________________________________ Homopolymer Homopolymer Homo- Homo- average abs/cm.sup.1 abs/cm >0.01.sup.2 polymer polymer 1260- 1480- 1260- 1480- Cpd Example n.sub.1.31 n.sub.1.31 calc 1360 nm 1580 nm 1360 nm 1580__________________________________________________________________________ nmI 6 1.515 1.523 .004 .012 1350-1360 1480-1580 IV 2 1.488 1.465 -- -- -- -- V 1 1.523 1.487 .006 .012 1343-1360 1480-1580 VI 5 1.547 1.550 .003 .005 1350-1360 1480-1485 VIII 4 1.465 1.452 .002 .008 1352-1360 1480-1500 VIII 22 1.380 1.348 .003 .006 1357-1360 none IX 9 1.444 1.405 -- -- -- -- X 3 1.424 1.386 .006 .06 1350-1360 1480-1580 XI 7 1.418 1.386 .004 .002 1340-1360 none XII 15 1.368 1.331 -- -- -- -- XIII 8 1.446 1.421 .003 .003 1345-1360 none 10 1.503 1.492 .006 .007 1348-1360 1480-1500 11 1.441 1.425 .003 .003 1355-1360 none__________________________________________________________________________ .sup.1 Average Abs/cm is the average light absorption per centimeter over the wavelength region noted. The target value is <0.01. .sup.2 Abs/cm >0.01 indicates those parts of the wavelength region where absorption/cm exceeds 0.01. (--) in Table 1 and succeeding Tables means n measurement taken.
The data of Table 1 show that a number of candidate haloacrylates have acceptably low absorbances in the target wavelength regions. In addition, these data show that homopolymer refractive index calculations (W. Groh and A. Zimmermann, Macromolecules, 24, (December, 1991), p. 6660) cannot predict the observed refractive index, particularly in light of a need to predict refractive index with accuracy in the third decimal point.
As mentioned previously, the halogenated acrylates of the present invention are relatively easy to polymerize. Like most acrylates, they are free radically polymerizable, often in less-than-rigorous conditions. In other words, although oxygen normally must be excluded from the area where an acrylate polymerization is performed, other materials (e.g., water) need not be so excluded.
As with most acrylates, the free radical polymerization of the halogenated acrylates of the present invention can be initiated by heat or by light, optionally but preferably in the presence of a thermal or photo initiator, respectively. Of these two types of initiation, photoinitiation, particularly UV-type photoinitiation, is preferred. In choosing an initiator, consideration of the aforementioned optical loss goals should be considered. For instance, certain UV initiators are highly absorptive in near infrared wavelengths. One UV initiator that has not proven to be especially absorptive in the wavelengths of interest is 2,2-diethoxyacetophene, Ph--C(O)CH(OCH 2 CH 3 ) 2 , wherein Ph is phenyl, hereinafter referred to as DEAP.
As with synthesis details discussed previously, choice of solvent(s), temperature, pressure, and other polymerization conditions are within the level of skill possessed by the ordinarily skilled artisan. Nevertheless, further details on similar polymerizations can be found at, for example, S. R. Sandler and W. Karo in Polymer Syntheses Vol. 1, 2nd Ed., Ch. 10 (pp 317-376) Academic Press, Inc., New York (1992).
Optionally, halogenated acrylate polymers of the invention may be crosslinked. Physical property changes achieved by crosslinking acrylate polymers include elevated Tg, increased strength, reduced swelling when exposed to solvent or other small molecules, and reduced flexibility. All of these may be highly desirable in achieving the "Bellcore Specifications" requirements for optical branching components prepared from acrylates of this invention. Typical acrylate crosslinkers have C--H bonds in addition to those in the acrylate functionality and may detrimentally affect optical absorbances in the important 1260 to 1360 nm and 1480 to 1580 nm wavelength regions (supra). Thus, there is a need for polyfunctional acrylate crosslinkers with fewer C--H bonds in the molecule, preferably with CH only in the acryloyl group and on the α-carbon atoms of the polyol moiety, more preferably limiting the C--H bonds to only those of the acrylate groups (i.e., no other C--H bonds in the molecule). In an optical device, the crosslinker may be present at a relatively minor component and, as such, a higher hydrogen content can be tolerated. Acrylates prepared from perhalogenated aromatic polyols fit this criterion. Illustrative examples of these polyfunctional acrylates include tetrafluorohydroquinone diacrylate (XX), tetrafluororesorcinol diacrylate (XXI), and octafluoro-4,4'-biphenol diacrylate (XXII). Acrylates of other halogenated (chlorinated or brominated) aromatic polyols may also be useful as crosslinkers of this invention. The corresponding polyfunctional homologous methacrylate crosslinkers may be substituted for any of the acrylate crosslinkers noted herein. ##STR16##
A number of brominated aromatic polyols may be readily purchased or can be synthesized, e.g., by the reaction of bromine with an aromatic polyol as is known in the art. Reaction of the brominated aromatic polyol with, for example, acryloyl chloride in the presence of a base such as triethylamine provides the desired acrylates of the brominated aromatic polyols. Illustrative examples of acrylated perhalogenated aromatic polyols include tetrachlorohydroquinone diacrylate, tetrabromocatechol diacrylate (XXIII), tetrachlorocatechol diacrylate, tetrabromoresorcinol diacrylate, tetrachlororesorcinol diacrylate, tribromophloroglucinol triacrylate (XXIV), tribromopyrrogallol triacrylate (XXV), and tribromo-1,2,4-benzenetriol triacrylate (XXVI).
Tribromoresorcinol diacrylate and trichlororesorcinol diacrylate can also be useful as crosslinkers. They may be useful in optical devices where the number of hydrogen atoms is less important. ##STR17##
Non-aromatic acyclic aliphatic halogenated polyol polyacrylates may also be useful as crosslinking agents in the invention. Polyacrylates can be prepared by, e.g., the reaction of a perhalogenated polyol with an acryloyl halide, preferably acryloyl chloride. Perhalogenated polyols can be prepared by the perfluorination of an aliphatic hydrocarbon-polyols or a halogenated, preferably chlorinated, aliphatic polyol by known fluorination methods, such as direct fluorination.
Acyclic aliphatic halogenated polyol polyacrylates can have the general formula R 9 f (CR 18 R f OC(O)CH═CH 2 ) q , wherein R 18 can be H or F, R f is as previously defined, q can be a whole number of 2 or greater, preferably from 2 to 6, more preferably from 2 to 4, and R 9 f preferably is an acyclic aliphatic halogenated group, free of ethylenic or other carbon--carbon unsaturation, having at least 1 carbon atom and optionally can comprise up to 50, preferably up to 10, non-carbon atoms such as oxygen, nitrogen, and sulfur in the aliphatic chain. R 9 f can comprise an oligomeric polyether, oligomeric polyamine, oligomeric polythiol or polyetheramine, such that the total number of atoms in the R 9 f chain (i.e., the combination of carbon atoms and linking oxygen, nitrogen or sulfur atoms) can be up to 150, preferably up to 50, more preferably up to 25, and most preferably no more than 20. Halogen atoms comprising the R 9 f group can be fluorine, chlorine or bromine, preferably fluorine or chlorine, more preferably a combination of fluorine and chlorine, and most preferably exclusively fluorine.
Representative acyclic aliphatic halogenated polyol polyacrylates are represented by the following formulae of fluorinated acrylates:
CF.sub.3 CH(OC(O)CH═CH.sub.2)CF.sub.2 O(CF.sub.2).sub.4 OCF.sub.2 CH(OC(O)CH═CH.sub.2)CF.sub.3 XXVII
CF.sub.3 CF(OC(O)CH═CH.sub.2)CF.sub.2 OCF.sub.2 CF(OC(O)CH═CH.sub.2)CF.sub.2 OCF.sub.2 CF(OC(O)CH═CH.sub.2)CF.sub.3 XXVIII
Halogenated acrylates of the present invention are useful in the preparation of polymers wherein the refractive index and the optical loss of the polymer must be carefully controlled. Polymers and copolymers prepared from the monomers find use in the manufacture of optical devices such as splitters, couplers, light guides, and waveguides. In addition, (co)polymers of the present invention find use as adhesives and index matching compounds for joining optical elements such as lenses, mirrors, optical fibers, light guides, and waveguides. (Co)polymers of the invention find further use as cladding and/or protective materials for optical devices such as those named above as well as optical fibers.
In addition to the aforementioned utilities, the inventive monomers and polymers are useful in a variety of applications such as flame retardants, protective coatings, and adhesives. Acrylates from brominated aromatic polyols can have utility in raising the refractive index of any acrylate system requiring crosslinking and/or flame resistance.
Objects and advantages of this invention are further illustrated by the following examples. The particular materials and amounts thereof, as well as other conditions and details, recited in these examples should not be used to unduly limit this invention.
EXAMPLES
Unless otherwise noted, all materials are commercially available from Aldrich Chemical Co. (Milwaukee, Wis.). "Room temperature" or "ambient temperature" means about 21° C. All chemical structures synthesized were confirmed by spectroscopic analysis.
Test Methods
Glass Transition Temperature (Tg)
Polymer films were prepared from liquified monomers (or monomer mixtures) that were doped with 0.2-0.5% by weight, based upon the total weight of polymerizable monomer(s), of a photoinitiator, preferably PhC(O)CH(OCH 2 CH 3 ) 2 (DEAP), syringe-filtered, deoxygenated, placed between two silicon-treated polyethylene terephthalate (PET) release liners and exposed to ultra-violet radiation from an Oriel 50 watt mercury arc lamp (Oriel Corp., Stratford, Conn.) or a Sylvania Blacklight fluorescent bulb (Sylvania 350 BL bulb, Siemens Corp./Osram Sylvania Inc., Danvers, Conn.) for 30-60 minutes at approximately 23° C. The polymeric films were further heated at 60-70° C. for approximately 30 minutes, then baked at 120° C. in an oven for several hours to ensure complete cure. The release liners were removed and the films were dried in a forced-air oven at 105° C. for at least 4 hours but not longer than 10 hours. The glass transition temperature (Tg) of each sample was determined by Differential Scanning Calorimetry using a Perkin-Elmer 7-Series Thermal Analysis System (Perkin-Elmer Corp., Norwalk, Conn.) with a general temperature range of -50 to 200° C. Tg values were determined according to ASTM protocol E1356-91 except a 20° C./minute ramp was used. If a transition could not be found in the general range, the temperature range was expanded as needed. Measurements were made after two heat and cool cycles. The Tg was recorded as a midpoint determination of the point at which the derivative of the interpolated slope of the transition equaled zero.
Refractive Index (n.sub.λ)
The index of refraction was determined by inserting an optical fiber capable of carrying light at the required wavelength n.sub.λ (typically, an 8 mW continuous wave laser diode at 1300 nm) into a liquid monomer or mixture of monomers, polymerizing the monomer(s) as described above to obtain a polymer, and measuring the intensity of the back reflection from the interface of the fiber and the sample. This was compared to the intensity of back-reflection when the same fiber was immersed in a material of known index (water) at the probing wavelength. Using the value of the refractive index of the fiber itself, the index of the probed material was calculated. Solid materials were first melted and the fiber inserted. In order to increase sensitivity of the measurements, the intensity of the incident light was modulated with a square-wave generator from a function generator (HP 8013A Pulse Generator, Hewlett Packard Instruments, Palo Alto, Calif.) and the detected signal analyzed using a lock-in detector (Stanford Research Systems Model SR510 Lock-In Amplifier, Stanford Research Systems Inc., Sunnyvale, Calif.) which was given the same square-wave reference signal. The refractive index measurements were reproducible to ±0.0015.
Optical Absorbance
Absorbance measurements were made on polymerized cylindrical plugs of sample. The plug typically had a diameter of 0.5 cm and height of 1 cm. Liquefied monomer was doped with 0.2% by weight DEAP, filtered, deoxygenated, and placed in a plastic mold prior to polymerization. Polymerization was effected by exposure to a UV lamp, typically Oriel Model 6281, for 30 minutes followed by heat annealing at 60-80° C. under UV light for an additional time of from 30 minutes to several hours in order to complete the polymerization reaction. Absorbance of the plugs was measured using a UV spectrometer (Model UV-3101 PC, Shimadzu Scientific Instruments, Inc., Columbia, Md.) equipped with an integrating sphere. To correct for the loss of probe light intensity due to reflection and scattering from the surface of the plug, which would be measured as an absorption loss, a baseline absorption (the loss recorded at 1050-1070 nm) was subtracted from the entire spectrum.
Example 1
Heptafluoronaphthyl acrylate (Compound V)
For about 3.5 hours, a mixture of 25 g octafluoronaphthalene (PCR Inc.; Gainesville, Fla.), 12 g KOH, and 100 mL tertiary butyl alcohol was refluxed. Water was added, and the tertiary butyl alcohol was distilled from the reaction mixture. The residue remaining in the flask was acidified with HCl and the aqueous mixture was extracted three times with 75 mL dichloromethane. The combined extracts were washed twice with 150 mL distilled water, dried over MgSO 4 , and rotary evaporated to yield a semi-crystalline solid. Recrystallization from hot hexanes gave 18 g heptafluoro-2-naphthol (72% yield) as slightly tan colored crystals.
In 150 mL acetonitrile, 15 g heptafluoro-2-naphthol was dissolved and cooled to 0° C. before 12 mL triethylamine and 7 mL acryloyl chloride, sequentially, were added slowly by syringe. This resulted in the formation of a light colored precipitate. The reaction was stirred for about two hours at 0° C. and about two hours at room temperature, then poured onto ice and allowed to warm to room temperature and extracted three times with 40 mL dichloromethane. The combined extracts were washed twice with 100 mL distilled water, dried over MgSO 4 , and rotary evaporated to yield a reddish orange colored oil. Vacuum distillation (75-78° C., 67 Pa) gave 16.3 g (90% yield) of 2-acryloyloxyheptafluoronaphthalene (compound V) as a colorless liquid. A homopolymer prepared as described in Example 13, below, from the acrylate had a refractive index n 1 .31 of 1.523, and average abs/cm of 0.006 (1260-1360 nm) and average abs/cm of 0.12 (1480-1580 nm).
Example 2
1-Pentafluorophenyl-1-pentachlorophenyl- 1-acryloyloxyheptafluoroethylether (Compound IV)
Hexachlorobenzene (35 g) was slurried in 160 ml of anhydrous ethyl ether at -40° C. A 2.5 M hexanes solution of n-butyllithium (54.1 mL) was added, and the reaction was stirred for 30 minutes at -40° C. Perfluoro-2-ethoxyacetylfluoride (40 g, 72% pure, prepared from 2-ethoxyethyl acetate by the method described in Example I of U.S. Pat. No. 5,326,919, incorporated herein by reference) was added to the -40° C. reaction mixture which was then allowed to warm slowly to room temperature. The reaction mixture was quenched with 200 mL of cold 5% aqueous HCl. The aqueous mixture was extracted with ethyl ether and the extracts were dried over MgSO 4 and rotary evaporated to give pentachlorophenyl perfluoroethoxymethyl ketone (49% crude yield). Vacuum distillation (105-109° C., 240 Pa) using a 15 cm Vigreux column gave 19.7 g of a colorless liquid which slowly crystallized on standing.
About 2.1 g magnesium metal turnings (J. T. Baker Inc.; Phillipsburg, N.J.) were dried by heating under a nitrogen purge, cooled, and suspended in 50 mL of anhydrous ethyl ether in a nitrogen atmosphere. A mixture of 8.4 g of chloropentafluorobenzene and 8.1 g of dibromoethane was added dropwise to the suspension. The reaction mixture was stirred at a temperature below 30° C. for 95 minutes in an ice bath. Pentachlorophenyl perfluoroethoxymethyl ketone (19.4 g) dissolved in 20 mL of ethyl ether was added and approximately one half of the ethyl ether was distilled from the reaction flask. Anhydrous 2-methoxyethyl ether (50 mL) was added, and the reaction mixture was heated to 75° C. for one hour. The reaction was quenched with 150 mL of 10% aqueous HCl, extracted with dichloromethane, and the extracts were dried over MgSO 4 and rotary evaporated to an oil. Chromatography on a 5×35 cm silica gel column (230-400 mesh, 60 Å) using 4:1 hexane : toluene as the elution solvent gave 15.1 g (61% yield) of 99.9% pure 1-pentafluorophenyl(1-pentachlorophenyl)(2-pentafluoroethoxy)difluoroethanol as a colorless hard wax.
A 14.8 g sample of 1-pentafluorophenyl(1-pentachlorophenyl)(2-pentafluoroethoxy)difluoroethanol in 150 mL of dichloromethane was cooled to 5° C. under a dry nitrogen atmosphere. Acryloyl chloride (2.1 mL) was added, followed by dropwise addition of dry, distilled triethylamine (3.6 mL, J. T. Baker). The reaction mixture was refluxed for 90 minutes, cooled to room temperature, stirred for 14 hours, and quenched with 250 mL of water. The organic layer was collected and rotary evaporated to give a yellow oil. Chromatography on a 5×40 cm silica gel column (230-400 mesh, 60 Å) using 8:1 hexane-ethyl acetate as the eluting solvent gave 12.9 g (80% yield) of 1-pentafluorophenyl-1-pentachlorophenyl-1-acryloyloxyheptafluoro-ethylether (compound IV) as a colorless liquid.
Example 3
1-Acryloyoxy- 1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethane (Compound X)
About 9.7 g magnesium metal turnings were dried by heating under a nitrogen purge, cooled, and suspended in 250 mL anhydrous ethyl ether in a dry nitrogen atmosphere. A mixture of 40.5 g chloropentafluorobenzene and 37.6 g dibromoethane was added dropwise to the suspension and the reaction mixture was stirred for one hour at less than 30° C. in an ice bath. About 34.8 g perfluoro-2-(2-ethoxyethoxy)acetylfluoride, prepared by direct fluorination of di(ethylene glycol) ethyl ether acetate as described in the previously incorporated Example 1 of U.S. Pat. No. 5,326,919, was added dropwise, and the reaction was stirred at room temperature for 18 hours. The reaction was quenched with dilute aqueous HCl and extracted with dichloromethane. After drying over MgSO 4 , the solvent was removed by rotary evaporation and the residue was vacuum distilled (136-138° C., 1330 Pa) to give 44.2 g (36% yield) of 1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethanol as a pale yellow liquid.
A 15.4 g sample of 1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethanol in 50 mL dichloromethane was cooled to 5° C. under an atmosphere of dry nitrogen. Acryloyl chloride (2.05 mL) was added followed by the dropwise addition of 3.5 mL dry, distilled triethylamine. The reaction mixture was refluxed for one hour and an additional 0.35 mL acryloyl chloride and 0.35 mL triethylamine were added. After an additional hour of reflux, the reaction was quenched with water and the organic layer was collected and rotary evaporated to give a pale yellow oil. Chromatography on a 5×40 cm silica gel column (230-400 mesh, 60 Å) using 12:1 hexane-ethyl acetate as the eluting solvent gave 14.4 g 1-acryloyoxy-1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethane (88% yield) (compound X) as a colorless liquid.
Example 4
5-Pentafluorophenoxy-3,4,6-trifluoro-2-trifluoromethylphenyl acrylate (Compound VII)
A mixture of 98.4 g pentafluorophenol, 0.1 g sodium saccharin, and 120 mL hexamethyldisilazane was stirred at 73° C. for 17 hours after the initial vigorous reaction. Distillation at 160-61° C. using a 15 cm Vigreux column yielded 119.3 g, 87% of pentafluorophenoxytrimethylsilane, C 6 F 5 OSi(CH 3 ) 3 .
A 56.2 g sample of pentafluorophenoxytrimethylsilane was mixed with 50.0 g octafluorotoluene, 3.0 g anhydrous CsF (Acros Organics: Pittsburgh, Pa.) and 100 mL anhydrous acetonitrile under nitrogen and stirred at reflux. The reaction was followed by GLC for 4 days, with addition of 3.4 g additional hexamethyldisilazane to reconvert traces of pentafluorophenol to the silyl derivative. The mixture was quenched in water, extracted with diethyl ether, dried over MgSO 4 , and concentrated on a rotary evaporator. The oily residue was distilled (80-100° C., 107 Pa) to give 74.7 g (88% yield) of 4-trifluoromethylnonafluorodiphenyl ether, C 6 F 5 OC 6 F 4 -4--CF 3 , and minor amounts of positional isomers thereof
All of the product from the previous paragraph was mixed with 14.7 g 85% KOH in 250 mL t-butanol, and the mixture was refluxed for 17 hours. The reaction mixture was quenched with dilute aqueous HCl, extracted with CH 2 Cl 2 , dried over MgSO 4 , and the extracts concentrated on a rotary evaporator. The product was vacuum distilled (97-120° C., 40 Pa) to give 47.8 g (64%) of a mixture of isomers of 2-hydroxy-4-pentafluorophenoxyhexafluorotoluene.
The isomeric mixture (47.8 g) was mixed with 12.5 mL acryloyl chloride in 200 mL cold methylene chloride and treated with 20 mL triethylamine dropwise. The mixture was stirred for 17 hours, filtered, and the filtrate was concentrated on a rotary evaporator. The residue was extracted with ethyl ether and the extracts were filtered and concentrated, and the residue was subjected to flash chromatography on about 450 cm 3 of silica gel. Elution with 2000 mL hexanes gave 40.7 g isomeric acryloyloxy-4-pentafluorophenoxyhexafluorotoluenes (75% yield) as a colorless liquid. Based on 19 F-NMR analysis, the main isomer was 2-acryloyloxy-4-pentafluorophenoxyhexafluorotoluene (compound VII).
Example 5
2,4,6-Trichlorodifluorophenyl acrylate (Compound VI)
In a 2 L 3-neck round bottomed flask equipped with an overhead stirrer were placed 120 g (85% pure) KOH, 200 g 1,3,5-trichlortrifluorobenzene (Oakwood Products, Inc.; West Columbia, S.C.), and 600 mL t-butanol. The mixture was stirred and refluxed for 4 hours. Approximately 500 mL t-butanol was distilled from the reaction mixture. The flask was cooled to room temperature and 600 mL acetonitrile was added. The flask was further cooled in an ice bath and 138 mL acryloyl chloride were added dropwise over the course of two hours. The reaction was stirred for an hour at 0° C. followed by two hours at room temperature. The reaction was then quenched with ice water, acidified with dilute HCl, and extracted with dichloromethane. The extracts were washed with saturated aqueous sodium bicarbonate and distilled water, then dried over MgSO 4 , filtered, and concentrated on a rotary evaporator. The crude product was vacuum distilled (96-105° C., 13-130 Pa) to give 219 g 2,4,6-trichlorodifluorophenyl acrylate (89.7% yield) (compound VI) as a colorless liquid which crystallized on standing.
Example 6
Bromotetrafluorophenyl acrylate (Compound I)
As in Example 5, 120 g KOH, 110 mL bromopentafluorobenzene (Oakwood Products, Inc.), and 500 mL t-butanol were combined. The mixture was stirred and refluxed for 4 hours and then approximately 400 mL t-butanol was distilled from the reaction mixture. The flask was cooled to room temperature and 500 mL acetonitrile was added. The flask was further cooled in an ice bath and 100 mL acryloyl chloride was added dropwise over the course of an hour. The reaction was stirred for an hour at 0° C. followed by 16 hours at room temperature, then quenched with ice water, acidified with dilute HCl, and extracted with dichloromethane. The extracts were washed with saturated aqueous sodium bicarbonate and distilled water, then dried over MgSO 4 , filtered, and concentrated on a rotary evaporator. The crude product was vacuum distilled (98-102° C., 1600 Pa) to give 177 g (67% yield) of a mixture of bromopentafluorophenyl acrylate isomers as a colorless liquid. Analysis by 19 F NMR spectroscopy indicated that the major isomer was para-bromopentafluorophenyl acrylate (compound I).
Example 7
1-Acryloyloxy-1-pentafluorophenylperfluorocyclohexane (Compound XI)
Under a nitrogen atmosphere, 60 g bromopentafluorobenzene in 200 mL dry ether were added to 6.32 g magnesium at a rate that maintained a steady reflux. The reaction was stirred for one additional hour. Perfluorocyclohexanone (prepared, for example, as in U.S. Pat. No. 3,321,515, Examples 65-68) (67.5 g) was added in one portion and the reaction allowed to stir for about 16 hours. The reaction mixture was quenched with 200 mL of 10% HCl and extracted twice with 150 mL CH 2 Cl 2 . Drying of the CH 2 Cl 2 layer (on MgSO 4 ) and rotary evaporation gave an oil. Vacuum distillation (82° C., 80 Pa) gave 74.5 g 1-pentafluorophenylperfluorocyclohexanol (70% yield) as a colorless liquid.
Under a N 2 atmosphere, 4.63 mL acryloyl chloride was added via syringe to an ice-cold solution of 21.69 g 1-pentafluorophenylperfluorocyclohexanol in 100 mL dry ether. Triethylamine was distilled from CaH 2 and 7.9 mL (56.3 mmol) was added via syringe. The reaction was stirred for 30 minutes in an ice-bath and stirred at room temperature for about 16 hours, then filtered and rotary evaporated to give an oily solid. This was passed through a short path silica gel column with CH 2 Cl 2 as the eluent to give an oil after evaporation. Vacuum distillation (77-80° C., 67 Pa) gave 15.2 g (63% yield) of 1-acryloyloxy-1-pentafluorophenylperfluorocyclohexane (compound XI) as a colorless liquid.
Example 8
1-Acryloyloxy-1-(3,5-dichloro-2,4,6-trifluorophenyl) perfluorocyclohexane (Compound XIII)
Under a N 2 atmosphere 29.5 g of 1,3,5-trichloro-2,4,6-trifluorobenzene (Oakwood Products, Inc.) were dissolved in 150 mL dry ethyl ether. The solution was cooled to -78° C. in an acetone/dry-ice bath, then treated with 62.7 mL n-butyllithium (2 M solution in hexanes) over a two-hour period. Stirring was continued for 3 hours at -78° C. Via syringe, 34.8 g perfluorocyclohexanone were added, and the mixture was stirred at room temperature for 16 hours. The reaction was quenched with dilute HCl and extracted with ethyl ether, and the extracts were dried (using MgSO 4 ) and rotary evaporated. Vacuum distillation (118-120° C., 80-110 Pa) gave 37.3 g 1-(3,5-dichloro-2,4,6-trifluorophenyl) perfluorocyclohexanol (62% yield) as a colorless liquid.
Under a N 2 atmosphere, 4.43 mL acryloyl chloride were added via syringe to an ice-cold solution of 20 g 1-(3,5-dichloro-2,4,6-trifluorophenyl)perfluorocyclohexanol in 150 mL dry ethyl ether. Via syringe, 7.6 mL triethylamine (freshly distilled from CaH 2 ) was added, stirring was continued for 10 minutes in the ice-bath, after which the reaction mixture was stirred at room temperature for about 18 hours. The reaction mixture was filtered and the residue washed with petroleum ether. The filtrate and washes were combined and rotary evaporated to give an oil that was vacuum distilled (112-119° C., 80 Pa) to give 12 g (54% yield) of 1-acryloyl-1-(3,5-dichloro-2,4,6-trifluorophenyl)perfluorocyclohexane (compound XIII) as an oil that solidified on standing.
Example 9
2-Acryloyloxy-1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}-2-pentachlorophenylpentafluoropropane (Compound IX)
Under a nitrogen atmosphere, 21.4 g hexachlorobenzene was suspended in 200 mL dry ethyl ether and the reaction flask was cooled to -40° C. in an acetonitrile/dry-ice bath. A 1.6 M hexanes solution (47.1 mL) of n-butyllithium was added by syringe and the reaction was stirred at -40° C. for two hours. A 35 g sample of 1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}pentafluoroacetone, prepared by the method as described in Example 23, below, was added in one portion and the reaction was allowed to come to room temperature while stirring for about 16 hours). The reaction was quenched with dilute aqueous HCl and the mixture was extracted with ethyl ether. The extract was dried (with MgSO 4 ) and rotary evaporated to give an oil. Vacuum distillation (133-135° C., 160 Pa) gave 10 g 1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}-2-pentachlorophenylpentafluoro-2-propanol (18% yield) as a colorless liquid.
Under an N 2 atmosphere, an ice-cold solution of 8.12 g of the above perfluoro alcohol in 100 mL dry ethyl ether was treated with 1.03 mL acryloyl chloride via syringe. Triethylamine (1.8 mL, distilled from CaH 2 ) was added via syringe, and the reaction was stirred at room temperature for about 16 hours. The reaction mixture was filtered and rotary evaporated to an oily solid. The oily solid was extracted with petroleum ether and the extracts were concentrated to a viscous oil. This oil was vacuum distilled (140-143° C., 120 Pa) to give 5.5 g (63% yield) of 2-acryloyloxy-1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoro-ethoxy}-2-pentachlorophenylpentafluoropropane (compound IX) as a colorless oil.
Example 10
Acryloyloxychlorooctafluorodiphenyl ether (isomeric mixture)
A mixture of 4.00 g pentafluorophenol, 4.00 g chloropentafluorobenzene, 0.12 g 18-crown-6 ether, 1.4 g powdered 85% KOH, and 15 mL diglyme was stirred at 130° C. for 18 hours. The cooled mixture was washed with water, extracted with methylene chloride, and the extracts rotary evaporated to yield 4.6 g of a sticky solid. Vacuum distillation (85-95° C., 33 Pa) of the combined residues from several condensations yielded 23.6 g of solid product that melted at 58-63° C. Analysis by GC/MS showed the solid to be a mixture of two chlorononafluorodiphenyl ether isomers.
The chlorononafluorodiphenyl ethers (23.4 g) were mixed with 8.4 g of 85% KOH in 150 mL t-butanol and the mixture was refluxed for 17 hours. The reaction mixture was quenched with dilute HCl, extracted with CH 2 Cl 2 , dried over MgSO 4 , and concentrated on a rotary evaporator. The product was vacuum distilled (35° C., 66 Pa) to give 19.6 g (84%) of a mixture of seven chlorohydroxyoctafluorodiphenyl ether isomers which were confirmed by spectroscopic analysis.
The isomeric chlorohydroxyoctafluorodiphenyl ether mixture was mixed with 6.0 mL acryloyl chloride in 250 mL cold methylene chloride and 10 mL triethylamine was added dropwise. The mixture was stirred for 17 hours, filtered, and the filtrate was rotary evaporated. The residue (27.1 g) was extracted with ethyl ether and the extracts were filtered and concentrated on a rotary evaporator. This residue was subjected to flash chromatography on about 450 cm 3 of silica gel and eluted with hexanes to give 14.8 g (65% yield) of a mixture of seven isomers of chloro(acryloyloxy)octafluorodiphenyl ether as a colorless liquid confirmed by spectroscopic analysis.
Example 11
2-Acryloyloxy-2-pentafluorophenyl-3-(1,2,2-trichloro-1,2-difluoroethoxy)pentafluoropropane
An ethereal solution of pentafluorophenyl magnesium bromide was prepared under a N 2 atmosphere by the addition of 1 mL of a solution of 12.9 g bromopentafluorobenzene in 20 mL ethyl ether to 1.3 g magnesium. An exothermic reaction ensued and the remaining bromopentafluorobenzene solution was added at such a rate as to maintain a steady reflux. The solution was stirred for an additional 45 minutes, then treated with 16.7 g 1-(1,2,2-trichloro-1,2-difluoroethoxy)perfluoroacetone (84% pure), prepared as described in Example 21, below, and the mixture was stirred at room temperature for 72 hours. The reaction was quenched with 200 mL of 10% aqueous HCl and extracted with 150 mL dichloromethane. The extract was dried over MgSO 4 and concentrated to an oil by rotary evaporation. Vacuum distillation (75-80° C., 67 Pa) of the oil gave 14 g 2-pentafluorophenyl-3-(1,2,2-trichloro- 1,2-difluoroethoxy)pentafluoro-2-propanol (55% yield) as a colorless liquid.
A 12.2 g sample of the propanol prepared above was dissolved in 50 mL dry ethyl ether under a nitrogen atmosphere and the solution was cooled in an ice bath. Acryloyl chloride (2.4 mL) was added by syringe. Triethylamine (3.0 g), distilled from CaH 2 , was then added by syringe and the reaction was stirred for 30 minutes at 0° C. The ice bath was removed and the reaction was stirred for an additional 2 hours. The reaction was filtered and the filtrate was washed twice with 25 mL water, then dried over MgSO 4 and rotary evaporated to an oily solid. The solid was dissolved in dichloromethane and filtered through silica gel and the filtrate was rotary evaporated to an oil. The oil was vacuum distilled (100-105° C., 67 Pa) to give 2-acryloyloxy-2-pentafluorophenyl-3-(1,2,2-trichloro-1,2- difluoroethoxy)pentafluoropropane (5.85 g, 43% yield) as a colorless liquid.
Example 12
1,2-bis(acryloyloxy)tetrabromobenzene (Compound XXIII)
Tetrabromocatechol (25 g) was dissolved in 250 mL acetonitrile and the solution was cooled to 0° C. in an ice bath. Triethylamine (17 mL) was added and the mixture was stirred at 0° C. for two hours. Acryloyl chloride (10 mL) was added dropwise by syringe, the ice bath was removed, and the reaction was stirred for 16 hours. The reaction was quenched with ice water and was acidified with dilute aqueous HCl to give a cream colored precipitate. The precipitate was collected by filtration and washed with water. Crystallization from hot methanol gave 20.6 g 1,2-bis(acryloyloxy)tetrabromobenzene (66% yield) as fine, colorless needles. The product had a melting point of 135-37° C.
Example 13
Preparation of polymers
To prepare polymers useful in the invention, liquidified monomers (or monomer mixtures) were doped with 0.2-0.5% by weight, based upon the total weight of polymerizable monomer(s), of a photoinitiator, preferably PhC(O)CH(OCH 2 CH 3 ) 2 (DEAP), syringe-filtered, deoxygenated and exposed to UV radiation from an Oriel™ 50 watt mercury arc lamp or a Sylvania Blacklight fluorescent bulb (Sylvania 350BL bulbs, Siemens Corp./Osram Sylvania Inc., Danvers, Conn.) for 30-60 minutes. The samples were typically heated to temperatures above their glass transition temperature during and after light exposure to ensure an acceptable extent of curing. Heating was effected either with an IR heat lamp or in a convection oven.
Representative homopolymers prepared according to this example are shown in Table 1, above, along with observed absorbance/cm -1 for the homopolymers. Table 2 shows refractive index and optical absorbance data for selected copolymers of the invention (the structure of whose monomers has been shown above), prepared as described in this example.
TABLE 2__________________________________________________________________________ Copolymer average abs/cm.sup.1 CopolymerMonomer 1 Monomer 2 Co- 1480- abs/cm >0.01.sup.2Compd Compd polymer 1260- 1580 1260-1360 1480-1580 # Wt % # Wt % n(1.31) 1360 nm nm nm nm__________________________________________________________________________I 44.06 XI 55.74 1.474 .0045 .018 1340-1360 1480-1580 VII 83.22 X 16.59 1.447 .002 .005 1345-1360 none Ex. 10 45.4 X 54.6 1.459 .004 .005 1355-1360 none Ex. 10 48.46 XI 51.34 1.458 .0025 .01 1350-1360 1480-1500 VI 31.2 XI 68.8 1.459 .006 .013 1345-1360 1480-1580__________________________________________________________________________ .sup.1 average abs/cm was the average light absorption per centimeter ove the wavelength region noted. The target value was <0.01. .sup.2 abs/cm >0.01 indicated those parts of the wavelength region where absorption/cm exceeded 0.01.
The data of Table 2 show that essentially identical refractive indexes can be obtained for a number of copolymers having distinctly different makeup and low optical absorbances in the desired wavelength ranges can be achieved.
Example 14
Crosslinked Copolymers
Monomer solutions of pentafluorophenyl acrylate containing various weight percentages of three different crosslinkers, trimethylolpropane triacrylate (TMPTA), 1,1,5,5-tetrahydrohexafluoropentane-1,5-diol diacrylate (HFPDDA), and tetrafluorohydroquinone diacrylate (TFHQDA), and 0.2 weight percent 2,2-diethoxyacetophenone photoinitiator, were prepared. Polymer films, approximately 0.05 mm thick, were prepared from the mixtures by placing the monomer solutions between polycarbonate release liners that were then warmed to 80° C. on a hot plate and irradiated for 30 minutes with the light from two 15 watt fluorescent black lights (F15T8-BLB, General Electric Co., Schenectady, N.Y.) held 7.6 cm above the hot plate. Portions, approximately 25 mm square, were cut from each film sample and weighed. The square portions were then immersed in pentafluorophenyl acrylate for 15 minutes, rinsed with isopropanol, blown dry for 10 seconds with a stream of nitrogen gas, and weighed. The weight gain upon immersion in pentafluorophenyl acrylate monomer was taken as a measure of the amount of swelling of the polymer film. The results are shown in Table 3A; each entry represents the average of at least two separate measurements.
TABLE 3A______________________________________Crosslinker Crosslinker amount, wt % Average wt gain, %______________________________________TMPTA 5 55 HFPDDA 5 44 TFHQDA 5 18 TMPTA 10 2 HFPDDA 10 10 TFHQDA 10 7______________________________________
The data of Table 3 show that fluorinated crosslinkers, especially tetrafluorohydroquinone diacrylate, are useful in reducing the swelling of polymerized fluorinated acrylate compositions when placed in contact with fluorinated acrylate monomers. Reduction in swelling was related to increased dimensional stability of the polymer.
In a similar fashion, two crosslinkers, TMPTA and FPEGDA, were evaluated separately using a mixture of pentafluorophenyl acrylate and (perfluorocyclohexyl)acrylate (86/14 wt %). FPEGDA refers to CH 2 ═CHCOOCH 2 (CF 2 OCF 2 ) n CH 2 OCOCH═CH 2 , n˜6-12 made by acrylation of the diol prepared as in U.S. Pat. No. 5,384,374 by direct fluorination of diacetate of poly(ethylene glycol) (av. No. molecular wt of ˜600), methanolysis, and reduction with NaBH4. Because of its high molar volume, FPEGDA had very low optical loss in the infrared regions of interest. Polymer films were tested as above for swelling by pentafluorophenyl acrylate and the data are shown in Table 3B.
TABLE 3B______________________________________Crosslinker Crosslinker amount, wt % Wt % PFPA Absorbed______________________________________TMPTA 4 45 FPEGDA 5 79______________________________________
Example 15
Preparation of Haloacrylates and Homopolymers Thereof
Halogenated acrylates of the invention include those based upon the reaction of acryloyl chloride with: 1) perhalogenated tertiary carbinols, 2) perhalogenated phenols, and 3) perhalogenated naphthols; and 4) perhalogenated thiophenols.
Properties of homopolymers of halogenated acrylates having general formula XXIX based upon the esterification of acrylic acid with perhalogenated tertiary carbinols are shown in Table 4:
CH.sub.2 ═CHC(O)OCR.sup.10 R.sup.11 R.sup.12 XXIX
Haloacrylates described in Table 4 were prepared according to methods described in Examples 2, 3, 7, 8, 9, and 11. Their structures were confirmed by spectroscopic analysis.
TABLE 4__________________________________________________________________________ Homopolymer average abs/cm.sup.1 average abs/cm <0.01.sup.2 1260-1360 1480-1580 1260-1360 1480-1580 Cpd R.sup.10 R.sup.11 R.sup.12 n.sub.1,31 nm nm nm nm__________________________________________________________________________4-1 CF.sub.3 CF.sub.3 C.sub.6 F.sub.5 1.416 .004 .009 1350-1360 1575-1580 4-2 CF.sub.3 CFCl.sub.2 CFClOCF.sub.2 C.sub.6 F.sub.5 1.441 .003 .003 1355-1360 none 4-3 CF.sub.2 Cl ClCF.sub.2 CF2OCF.sub.2 C.sub.6 F.sub.5 1.426 -- -- -- -- 4-4 CF.sub.2 Cl CF.sub.2 Cl C.sub.6 F.sub.5 1.459 -- -- -- -- 4-5 C.sub.4 F.sub.9 OCF.sub.2 C.sub.4 F.sub.9 OCF.sub.2 C.sub.6 F.sub.5 1.368 -- -- -- -- 4-6 CF.sub.3 C.sub.6 F.sub.13 C.sub.6 F.sub.5 1.380 .003 -.006 1357-1360 none4-7 --CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 -- C.sub.6 F.sub.5 1.418 .004 .002 1340-1360 none 4-8 --CF.sub.2 CF.sub.2 CF(Cl)CF.sub.2 CF.sub.2 -- C.sub.6 F.sub.5 1.430 -- -- -- -- 4-9 --CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 -- C.sub.6 F.sub.3 Cl.sub.2 1.446 .003 .003 1345-1360 none 410 --CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 -- C.sub.6 F.sub.4 Cl 1.423 -- -- -- --4-11 CF.sub.3 CF.sub.3 C.sub.6 Cl.sub.5 1.530 -- -- -- --4-12 --CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 -- C.sub.6 Cl.sub.5 1.500 -- -- -- --4-13 CF.sub.3 CF.sub.3 OCF.sub.2 C.sub.6 Cl.sub.5 1.506 -- -- -- -- 4-14 CF.sub.3 CF.sub.3 O-i--C.sub.3 F.sub.6 OCF.sub.2 C.sub.6 Cl.sub.5 1.450 .002 .004 1355-1360 none 4-15 CF.sub.3 CF.sub.3 O(C.sub.2 F.sub.4 O).sub.2 CF.sub.2 C.sub.6 Cl.sub.5 1.444 -- -- 4-16 C.sub.2 F.sub.5 OCF.sub.2 C.sub.2 F.sub.5 OCF.sub.2 C.sub.6 Cl.sub.5 1.449 -- -- -- -- 4-17 C.sub.4 F.sub.9 OCF.sub.2 C.sub.4 F.sub.9 OCF.sub.2 C.sub.6 Cl.sub.5 1.420 -- -- -- -- 4-18 C.sub.4 SCl.sub.3 CF.sub.2 Cl CF.sub.2 Cl 1.525 -- -- -- -- 4-19 C.sub.4 SCl.sub.3 CF.sub.3 C.sub.6 F.sub.13 1.435 -- -- -- -- 4-20 C.sub.6 F.sub.5 C.sub.2 F.sub.5 C.sub.6 F.sub.5 1.441 -- -- -- -- 4-21 C.sub.6 F.sub.5 C.sub.2 F.sub.5 OC.sub.2 F.sub.4 OCF.sub.2 C.sub.6 F.sub.5 1.424 .006 .06 1350-1360 1480-1580 4-22 C.sub.6 F.sub.5 CFCl.sub.2 CFClOC.sub.2 F.sub.4 C.sub.6 F.sub.5 1.450 -- -- -- -- 4-23 C.sub.6 F.sub.5 C.sub.2 F.sub.5 OC.sub.2 F.sub.4 OCF.sub.2 C.sub.6 Cl.sub.5 1.470 -- -- -- -- 4-24 C.sub.6 F.sub.5 C.sub.2 F.sub.5 OCF.sub.2 C.sub.6 Cl.sub.5 1.488 -- -- -- -- 4-25 C.sub.2 F.sub.5 OCF.sub.2 C.sub.2 F.sub.5 OCF.sub.2 C.sub.6 F.sub.5 1.390 -- -- -- --4-26 --CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 CF.sub.2 -- C.sub.6 Cl.sub.2 F.sub.2 -- 1.462 -- -- -- -- OC.sub.6 F.sub.5)__________________________________________________________________________ .sup.1 average abs/cm was the average light absorption per centimeter ove the wavelength region noted. The target value was <0.01. .sup.2 abs/cm <0.01 indicated those parts of the wavelength region where absorption/cm exceeded 0.01.4
The data of Table 4 and Table 5, below, show that the refractive index of homopolymers of the invention can be tailored dependent upon choice of halogenated groups in the structure.
Properties of halogenated acrylates having general formula XXX, based upon the reaction of acryloyl chloride with perhalogenated phenols are shown in Table 5: ##STR18##
Haloacrylates described in Table 5 were prepared according to methods described in Examples 4, 5, 6, and 10. Their structures were confirmed by spectroscopic analysis.
TABLE 5__________________________________________________________________________ Homopolymer Average Abs/cm.sup.1 Average Abs/cm >0.01.sup.2 1480-1580 1480-1580 Cmpd R.sup.13 R.sup.14 R.sup.15 R.sup.16 R.sup.17 n.sub.1.31 1260-1360 nm nm 1260-1360 nm__________________________________________________________________________ nm5-1 F F F F F 1.465 -- -- -- -- 5-2 F F Cl F F 1.500 -- -- -- -- 5-3 F F CF.sub.3 C.sub.6 F.sub.4 S F F 1.499 -- -- -- -- 5-4 F F ClC.sub.6 F.sub.4 O F F 1.503 .006 .007 1348-1360 1480-1500 5-5 F F BrC.sub.6 F.sub.4 O F F 1.512 -- -- -- -- 5-6 F F (C.sub.6 F.sub.5)C O.sub.2 F F 1.474 -- -- -- -- 5-7 CF.sub.3 F F C.sub.6 F.sub.5 O F 1.465 .002 .008 1352-1360 1480-1500 5-8 CF.sub.3 F F ClC.sub.6 F.sub.4 O F 1.505 -- -- -- -- 5-9 F F CF.sub.3 F F 1.444 -- -- -- -- 5-10 F F C.sub.6 F.sub.5 F F 1.477 -- -- -- -- 5-11 Cl F Cl F Cl 1.547 .003 .005 1350-1360 1480-1485 5-12 Cl Cl Cl Cl Cl 1.550 -- -- -- -- 5-13 F F CN F F 1.499 -- -- -- -- 5-14 F F C.sub.6 F.sub.5 S F F 1.508 -- -- -- -- 5-15 F F I F F 1.548 -- -- -- -- 5-16 Br F Br F F 1.558 -- -- -- -- 5-17 F F Br F F 1.515 .004 .012 1350-1360 1480-1580 5-18 Br F F Cl F 1.544 -- -- -- -- 5-19 CF.sub.3 F F Br F 1.487 -- -- -- --__________________________________________________________________________ .sup.1 average abs/cm was the average light absorption per centimeter ove the wavelength region noted. The target value was <0.01. .sup.2 abs/cm >0.01 indicated those parts of the wavelength region where absorption/cm exceeded 0.01.4
A perfluorothioacrylate corresponding to formula XXXI was prepared in a manner essentially as described previously by reaction of acryloyl chloride with pentafluorothiophenol (c.f, Examples 1, 5, 6, etc.). ##STR19## Compound XXXI had a melting point of less than 25° C., and the refractive index (n 1 .31) of the corresponding homopolymer was 1.516.
Example 16
Preparation of 1,3,5-tribromo-2,4-bisacryloyloxybenzene
Ten grams of 2,4,6-tribromoresorcinol was dissolved in 150 mL of acetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (4.7 mL) was added and the mixture was magnetically stirred. Triethyl amine (8.0 mL) was then added in a dropwise fashion and the reaction was maintained at 0° C. A precipitate formed upon addition of triethyl amine. After the triethyl amine addition, the reaction was stirred for one hour at 0° C. and 24 hours at room temperature. The reaction mixture was filtered and the filtrate was rotary evaporated to a brownish oily solid. The solid was washed with water and crystallized from hot hexanes to give 12 g (91%) of 1,3,5-tribromo-2,4-bisacryloyloxybenzene as colorless crystals.
Example 17
Preparation of tribromopyrogallol triacrylate (Compound XXV)
Pyrogallol (10 g) was dissolved in 150 mL of diethyl ether and bromine (12 mL in 50 mL of dichloromethane) was added dropwise over a 2 hour period to the stirred solution. The resulting reddish homogeneous solution was stirred for 16 hours. The reaction mixture was then rotary evaporated to a light red-brown semicrystalline solid. The solid was dissolved in 200 mL of diethyl ether and the solution was filtered. Heptane (200 mL) was added to the filtrate and the slightly cloudy solution was allowed to slowly evaporate to form fine, off-white needles of tribromopyrogallol (27.7 g, 96%).
Ten grams of tribromopyrogallol was dissolved in 200 mL of acetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (8 mL) was added and the mixture was magnetically stirred. Triethyl amine (13 mL) was then added in a dropwise fashion and the reaction was maintained at 0° C. A precipitate formed upon addition of triethyl amine. After the triethyl amine addition, the reaction was stirred for one hour at 0° C. and 16 hours at room temperature. The reaction mixture was filtered and the filtrate was rotary evaporated to a yellowish oil. The oil was washed with water and crystallized from hot hexanes to give 6.2 g (43%) of tribromopyrogallol triacrylate as colorless needles.
Example 18
Preparation of tribromophloroglucinol triacrylate (Compound XXIV)
Phloroglucinol dihydrate (10 g) was suspended in 150 mL of dichloromethane and bromine (12 mL in 50 mL of dichloromethane) was added dropwise over 2.5 hour period to the stirred suspension. The suspended phloroglucinol dissolved during the course of the bromine addition. After stirring for an additional 2 hours a two-phase solution was obtained. The pale orange dichloromethane supernatant solution was decanted from a small amount of a denser, dark red aqueous solution. The dichloromethane solution was rotary evaporated to a pinkish colored semicrystalline solid. The solid was dissolved in a 50 mL of acetone and 500 mL of heptane was slowly added with stirring to give beige crystals of tribromophloroglucinol (18.8 g, 84%).
Ten grams of tribromophloroglucinol was dissolved in 150 mL of acetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (8 mL) was added and the mixture was magnetically stirred. Triethyl amine (13 mL) was then added in a dropwise fashion and the reaction was maintained at 0° C. A precipitate formed upon addition of triethyl amine. After the triethyl amine addition, the reaction was stirred for one hour at 0° C. and 2 hours at room temperature. The reaction mixture was poured into ice water and a cream colored semicrystalline precipitate formed. The precipitate was collected by filtration, washed with water, and air dried. The solid was crystallized from hot heptanes to give 6.1 g (42%) of tribromophloroglucinol triacrylate as off-white needles.
Example 19
Use of brominated crosslinkers to modify the refractive index of hydrocarbon acrylates
Tetrabromocatechol diacrylate (Example 12) (1.0019 g) was dissolved in 3.9905 g phenoxyethyl acrylate (PEA) (CPS Chemical Co., Old Bridge, N.J.) to give a solution containing approximately 20% by weight of the diacrylate crosslinker. Tribromophloroglucinol triacrylate (Example 18) (0.4995 g) was dissolved in 2.0120 g PEA to give a solution containing approximately 20% by weight of the triacrylate crosslinker. DEAP photoinitiator (0.2% by weight) was added to the solutions and to a sample of pure PEA. Portions of these three samples were polymerized and the refractive indices of the polymers were measured as described above. The polymerized PEA gave a refractive index at 1.31 nm of 1.545. The polymerized PEA/20 wt % tetrabromocatechol diacrylate gave a refractive index at 1.31 nm of 1.561. The polymerized PEA/20 wt % tribromophloroglucinol triacrylate gave a refractive index at 1.31 nm of 1.555. Using the measured refractive index of PEA and calculated densities for the brominated crosslinkers (by methods known in the art), refractive indices were calculated for the homopolymers derived from the brominated crosslinkers. By this method a refractive index at 1.31 nm of 1.693 was calculated for polymerized tetrabromocatechol diacrylate and a refractive index at 1.31 nm of 1.628 was calculated for polymerized tribromophloroglucinol triacrylate. This example shows that the brominated crosslinkers can be used to crosslink acrylate monomers and that they are effective in increasing the refractive index of the resulting polymer.
Example 20
Use of brominated crosslinkers to modify the glass transition temperatures (Tg) of hydrocarbon acrylates
Tetrabromocatechol diacrylate (Example 12) (0.5084 g) was dissolved in 4.5006 g isobornyl acrylate (IBA) (San Esters Corp., N.Y.) to give a solution containing approximately 10% by weight of the diacrylate crosslinker. Tribromophloroglucinol triacrylate (Example 18) (0.5051 g) was dissolved in 4.4952 g IBA to give a solution containing approximately 10% by weight of the triacrylate crosslinker. DEAP photoinitiator (0.2% by weight) was added to the solutions and to a sample of pure IBA. Portions of these three samples were polymerized and the Tgs of the polymers were measured as described above. The Tg of polymerized IBA was found to be 62.5° C. The Tg of IBA copolymerized with 10 wt % tetrabromocatechol diacrylate was found to be 98.5° C. The Tg of IBA copolymerized with 10 wt % tribromophloroglucinol triacrylate was found to be 96° C. This example shows that the brominated crosslinkers can be used to crosslink acrylate monomers and that they are effective in increasing the glass transition temperature of the resulting polymer.
Example 21
1-(1,2,2-trichloro- 1,2-difluoroethoxy)perfluoroacetone
A mixture of 339 g trichloroethanol, 291 g propylene oxide and 17.7 g dry triethylamine was stirred in a 1-liter round bottom flask at 23° C. for four days, then washed with 2×400 mL 10% aq. HCl and 1×400 mL sat. aq. NaCl solution. The remaining organic solution was diluted with 200 mL methylene chloride and dried over MgSO 4 . The filtered solution was treated with a slight excess of trifluoroacetic anhydride, after which the solvent was removed and the residue distilled at 66° C. and 20 Pa to yield the corresponding trifluoromethyl acetate. The acetate was taken up in perfluoro N-methyl morpholine (PNMM, 3M Company, St. Paul, Minn.) and subjected to direct fluorination, as described in the previously-incorporated Example 1 of U.S. Pat. No. 5,236,919. The fluorinated ester was converted to the corresponding methyl hemi-ketal by addition of BF 3 /MeOH, and the hemi-ketal was converted to the desired ketone by distillation from conc. H 2 SO 4 . The structure of the ketone was verified by IR and 19 F NMR spectra.
Example 22
2-Acryloyloxy-2-pentafluorophenylperfluorooctane (Compound VIII)
An ethereal solution of pentafluorophenyl magnesium chloride was prepared from 20.2 g C 6 F 5 Cl, 4.8 g Mg and 100 mL diethyl ether (exothermic after initiation with BrC 2 H 4 Br). A dry-ice condenser was attached and 41.6 g perfluorooctanone (prepared according to the method described in U.S. Pat. No. 5,236,919, Example 1, incorporated herein by reference) was introduced directly into the solution. The reaction mixture was stirred overnight, then treated with dilute aq. HCl and distilled to give 45 g of the desired 2-pentafluorophenylperfluorooctan-2-ol at 78° C./67 Pa. A mixture of 29 g of the alcohol and 4.5 mL acryloyl chloride in 300 mL diethyl ether was treated with 5.05 g triethylamine at 0° C. and allowed to warm to 23° C. overnight with stirring. The reaction mixture was washed with water, dried over MgSO 4 , and stripped of solvent. Purification on a silica gel column (CH 2 Cl 2 /C 6 H 14 ; 1/3) and distillation at 85° C./1.0 Pa gave 21 g colorless liquid acrylate, confirmed by spectroscopic analysis.
Example 23
1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}pentafluoroaceton
CF.sub.3 OCF.sub.2 CF.sub.2 OCF.sub.2 CF.sub.2 OCF.sub.2 --CO--CF.sub.3
A mixture of 300 g 2-(2-methoxyethoxy)ethanol (Methyl Carbitol™), 174 g of propylene oxide, 17 ml of freshly distilled triethylamine, and 1 g of Adogen™ 464 phase transfer catalyst was sealed in a glass reactor and the mixture was left to stir for 4 days, then heated to 55° C. for 10 hours. Gas chromatography (GC) showed 77% conversion to the desired product with 7.5% starting alcohol and 15% higher homolog. The reaction mixture was diluted with 500 mL of CH 2 Cl 2 after which 250 mL of acetyl chloride was added dropwise to the stirred mixture with icebath cooling. The organic phase was washed with 700 mL of H 2 O and 750 mL saturated NaCl solution. After rotary evaporation, the residue was distilled under vacuum (115 to 135° C./120 Pa) to yield a 247 g of distillate that was 85% pure desired polyether acetate. Direct fluorination of the acetate gave a crude product that was treated with an excess of methanol to form the methyl hemi-ketal (CF 3 OCF 2 CF 2 OCF 2 CF 2 OCF 2 --C(OH)(OCH 3 )CF 3 ). The hemi-ketal was isolated by distillation (245.1 g), then distilled from 250 ml of concentrated H 2 SO 4 . The fraction from 99 to 106° C. (129.1 g) contained 91.6% desired ketone by GC. The material was characterized by IR and fluorine NMR.
Example 24
2,2,2-trichloro-1-(chloro(difluoro)methyl)-1-((2-chloro-1,1,2,2-tetrafluoroethoxy)(difluoro)methyl acrylate (Compound XVII)
In a manner similar to that described as method B by Zeifman et.al., Izv. Akad. Nauk, Ser. Khim, 2, 464-468 (1992), 31.5 g of the fluorochloroketone ClCF 2 CF 2 OCF 2 --CO--CF 2 Cl, synthesized from chloroethanol and epichlorohydrin in the manner described in Example 23, was added to a pre-dried reaction vessel containing 32.7 g of trichloroacetic acid in 100 mL hexamethylphosphoramide at 23° C. The solution was warmed to 60° C. until no additional CO 2 evolution was observed, then stirred 14 hours at 23° C. The mixture was quenched with 200 mL of 10% HCl solution and the organic layer was extracted into 100 mL of ethyl ether. The ether fraction was washed with 3×100 mL of dilute HCl solution, dried over MgSO 4 and evaporated with rotary evaporation. The residue (42.6 g) was distilled (58-62° C./173 Pa) to yield 7.7 g of carbinol (18%). This material was combined with that from a second run (6.3 g) and the combined carbinol (13.1 g ) was dissolved into 50 mL of CH 2 Cl 2 to which was added 3.8 mL of acryloyl chloride with icebath cooling. 4.8 g of dried triethylamine was added dropwise with stirring and the entire mixture was allowed to warm to 23° C. The mixture was washed with saturated NaCl solution, dried over MgSO 4 , filtered, solvent stripped and then purified by column chromatography (silica gel, 230-400 mesh, 60 A) using hexanes:ethyl acetate (8:1 by volume). 13 g of clear colorless acrylate was isolated. The structure was confirmed by proton and fluorine NMR and GC/MS. The clear colorless liquid was polymerized to give a clear solid homopolymer having n 1 .31 =1.443.
Example 25
2,2,3,3,4,4,5,5,6,6-decafluoro-1-(trichloromethyl)-1-cyclohexanol (Compound XVIII)
A solution of 30 g of perfluorocyclohexanone and 31.7 g of trichloroacetic acid was stirred in a pre-dried reaction vessel containing 113 mL of hexamethylphosphoramide. This mixture was cooled to -10° C. in a dry ice/acetone bath. Slight gas evolution was noted before and during the ketone addition. The stirred milky white reaction mixture was maintained at about 0° C. for an hour and then allowed to warm to 23° C. and stirring was continued 17 hours. The clear yellow solution was quenched with 150 mL of 10% HCl and then transferred to a separatory funnel with 400 mL of ethyl ether. This organic phase was washed with 4×500 mL of dilute HCl and then 300 mL of saturated NaCl solution. The solvent was removed by evaporation. The residue (33.7 g) contained 40.8% product by GC, confirmed by fluorine NMR. This carbinol can be converted to the corresponding acrylate by methods previously described (cf. Example 24).
Example 26
2,2,2-trichloro-1,1-di(2,3,4,5,6-pentafluorophenyl)-1-ethanol and (Compound XIX)
A mixture of 4.9 g of decafluorobenzophenone and 2.7 g of trichloroacetic acid was added to 15 mL of hexamethylphosphoramide. The stirred reaction mixture was maintain ed at about 0° C. for about 2 hours and t hen allowed to warm to room temperature and continue stirring at ambient temperature for the next 15 hours. The reaction mixture was characterized by GC and fluorine NMR to show a conversion of approximately 20% to the desired carbinol. This carbinol can be converted to the corresponding acrylate by methods previously described (cf. Example 24).
Example 27
CF.sub.3 CH(OC(O)CH═CH.sub.2)CF.sub.2 O(CF.sub.2).sub.4 OCF.sub.2 CH(OC(O)CH═CH.sub.2)CF.sub.3 (Compound XXVII)
A solution of 100 g of butane diol and 18 g of freshly distilled triethylamine was transferred into a 600 mL Parr reactor, followed by 135.3 g of propylene oxide. The reaction vessel was sealed and the solution was stirred and heated to 50° C. Within the first 35 minutes an exotherm began and the reaction mixture self heated to 140° C. The reaction slowly cooled to 50° C. and was maintained at this temperature for a total of 36 hours. An additional 40 mL of propylene oxide was added and the reaction was re-heated to 50° C. and left with stirring and heating for 24 hours. The contents of the reaction vessel were transferred into a 1000 mL 3-neck round-bottom flask with 150 mL of CH 2 Cl 2 . 200 mL of acetyl chloride was added to the stirred mixture with icebath cooling. After the addition, the icebath was removed and the mixture allowed to stir for 1 hour at 23° C. The mixture was washed with 400 mL of H 2 O, 400 mL of saturated NaCl solution, then dried over MgSO 4 . 147.7 g of the desired acetate was isolated by distillation (Bp=124 to 145° C./160 Pa). The structure was verified by proton NMR. The hydrocarbon acetate was fluorinated, isolated, and converted to the diketone as previously described in Example 23. The diketone can be converted to a diacrylate as described in U.S. Pat. No. 3,520,863, Example 15, incorporated herein by reference.
Example 28 ##STR20##
150 g of glycerol was weighed into a 600 mL Parr reactor. 250 mL (208 g) of propylene oxide was charged into the glycerol followed by 22.7 mL (16.5 g ) of freshly distilled triethylamine. The solution was stirred and heated to 50° C. for one hour, after which the temperature was raised to 70° C. An exotherm followed with a maximum temperature of 135° C. The mixture was stirred at of 70° C. for the next 18 hours. The reactor was cooled to 23° C. and the excess pressure vented into a hood. No glycerol triacetate was observed by GC, so the contents of the reaction vessel were transferred into a 1000 mL 3-neck round-bottom flask with 350 mL of CH 2 Cl 2 , and 360 mL of acetyl chloride were added to the stirred mixture with icebath cooling. After the addition, the icebath was removed and the mixture allowed to stir for 1 hour at room temperature. The mixture was washed with 800 mL of H 2 O, 500 mL of saturated NaCl solution, and dried over MgSO 4 . rotary evaporation of solvent gave a yellow residue (561.5 g). Distillation (166 to 188° C./160 Pa) gave 234 g of product that was found to comprise a mixture of 7% trifunctional with 1 propylene oxide group to 1 glycerol group (1:1, PO:Gly), 57% desired tri-functional (2:1, PO:Gly.), 29% trifunctional (3:1, PO:Gly.), and the balance of higher oligomers. The structures were verified by proton NMR. The hydrocarbon acetate was fluorinated, isolated, converted to the corresponding polyketone as previously described in Example 23. The polyketone can be converted to a polyacrylate as described in U.S. Pat. No. 3,520,863, Example 15, incorporated herein by reference.
Example 29
4-Pentafluorobenzoyloxy-2,3,5,6-tetrafluorophenyl acrylate
A mixture of 56.0 g C 6 F 6 in 300 mL 1M KOtBu/tBuOH heated at reflux 1 hr, and the organic product was recovered by washing with water and extraction with methylene chloride. The MgSO 4 -dried extract was stripped on a rotary evaporator to give 48.6 g of tan liquid, 92% C 6 F 5 OtBu and 4% di-t-butoxytetrafluorobenzene isomers by GC. Of this, 42.4 g was stirred at 60° for 22 hr with 25.0 g powdered KOH in 65 mL t-BuOH. Acidification of an aliquot of the cooled product showed 40% recovery, 20% desired phenol, and 40% byproduct di-t-butoxytetrafluorobenzene isomers. The phenol was separated by washing the reaction product with water and subsequently acidifying the collected water wash to yield 13.0 g of hydroxy-tetrafluorophenyl t-butyl ethers. A prior sample was analyzed by gc/ms and 19 F NMR and assigned as the para isomer (77%) and meta isomer (23%). 11.6 g was dissolved in 150 mL CH 2 Cl 2 , chilled in ice, treated with 8.0 mL triethylamine, and then treated dropwise with 12.0 g C 6 F 5 COCl. This was left standing for 3 days. Water washing, drying, and stripping gave 21.3 g low-melting solid, pentafluorobenzoyloxytetrafluorophenyl t-butyl ether. This was mixed with 23 mL trifluoroacetic acid and 2 mL water, warmed on a steam bath for 1.5 hr, and quenched in water and extracted with CH 2 Cl 2 , dried, and stripped to 18.6 g tan oil, pentafluorobenzoyloxytetrafluorophenol, confirmed by 19F NMR. This was dissolved in 150 mL CH 2 Cl 2 , 5.0 mL acryloyl chloride was added, and the ice-cooled mixture was treated with 10.0 mL triethylamine over about 1 min. Chromatography on 400 mL silica gel with hexane yielded the acylate as a slightly yellow liquid, 11 .3 g. The structure of the desired acrylate was confirmed by spectroscopy.
Example 30
3,12-Diacryloxy-3,12-Dihydrido-perfluoro-2,13-Dimethyltetradecane
(CF.sub.3).sub.2 CFCH(OCOCH═CH.sub.2)(CF.sub.2).sub.8 CH(OCOCH═CH.sub.2)CF(CF.sub.3).sub.2 (Compound XXXII)
Based on the chemistry reported by Smith, Fawcett, & Coffman, JACS, 84, p4285 (1962); the ketone, (CF 3 ) 2 CF--CO--(CF 2 ) 8 --CO--CF(CF 3 ) 2 , was synthesized as follows. 50 g of the di-acid fluoride (F--CO-(CF 2 ) 8 --CO-F ) was charged into a 600 ml Parr reactor with 0.6 g of anhydrous KF and 54 g of anhydrous diglyme. The reactor was sealed and cooled in dry ice. 33 g of hexafluoropropene was charged into the reactor. The reactor was heated to 100 degrees C over a period of 28 hours. The reactor was cooled and vented and the lower fluorochemical phase isolated (75.6 g, 94% yield) and washed with saturated NaCl solution. The organic was dried over MgSO 4 , filtered and distilled. A sample of the main cut (colorless clear low melting crystals) was characterized by 19F-NMR and IR. 32 g of this ketone was dissolved in 150 mL of anhydrous diglyme. 3.1 g of NaBH 4 , suspended in 20 mL of diglyme was added in 1 mL aliquots. The mixture was left to stir for 4 hours with water bath cooling to control the exotherm. The resulting heterogeneous mixture was decomposed with 5% HCl. The lower phase was isolated and the residual diglyme distilled to leave 28.8 g (89% yield) of a yellow solid. This solid was characterized by proton and fluorine NMR and IR to confirm the structure. 24 g of the solid was dissolved in 50 mL anhydrous CH 3 CN under a nitrogen atmosphere and charged with 6 g of acryloyl chloride at 5 degrees C. 6.7 g of triethyl amine was added dropwise to the stirred solution. The solid amine hydrochloride by-product was removed by filtration and 100 ml of CH 2 Cl 2 was added and the organic layer washed with saturated NaCl solution. The organic was then solvent stripped by rotary evaporation to leave the crude diacrylate. The structure was verified by proton and fluorine NMR.
Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be unduly limited to the illustrative embodiments set forth herein.
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Acrylates having a high degree of halogenation, as well as polymers that include one or more mer units derived from such acrylates provide materials having tailorable optical and physical properties. The polymers find utility particularly in optical devices including optical waveguides and interconnecting devices.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a method for preventing gas pressure in a pressure vessel from dropping below a minimum allowable pressure and, more particularly, to a method for preventing pressure in one or more pressure vessels in a hydrogen storage system from dropping below a minimum allowable pressure which monitors the normal tolerance-driven fluctuations in pressure readings at a pressure sensor downstream of a pressure regulator and, if a pressure drop in excess of the normal fluctuations is detected, shuts down the hydrogen storage system to prevent the pressure in the vessels from dropping too low.
[0003] 2. Discussion of the Related Art
[0004] Hydrogen is a very attractive fuel because it is clean and can be used to efficiently produce electricity in a fuel cell. The automotive industry expends significant resources in the development of hydrogen fuel cell systems as a source of power for vehicles. Such vehicles would be more efficient and generate fewer emissions than today's vehicles employing internal combustion engines.
[0005] Typically hydrogen gas is stored at high pressure in pressure vessels on the vehicle to provide the hydrogen necessary for the fuel cell system. The pressure in the vessels can be 700 bar or more. In one known design, the pressure vessels include an inner plastic liner that provides a gas tight seal for the hydrogen gas, and an outer carbon fiber composite layer that provides the structural integrity of the vessel. A hydrogen storage system typically includes at least one pressure regulator that reduces the pressure of the hydrogen gas from the high pressure of the vessels to a pressure suitable for the fuel cell system.
[0006] If the pressure within the vessels falls below a certain value, and the vessels are then refilled at a high rate of pressure increase, the inner liner layer may begin to separate from the outer structural layer. This separation could cause inner liner damage and loss of leak-tightness, and thus must be avoided. A current solution to avoid this separation is to maintain a high enough pressure within the vessels to prevent inner liner layer separation. For one exemplary vessel design, a minimum pressure of 20 bar must be maintained in the vessels to prevent the inner liner layer from separating from the outer structural layer.
[0007] One or more pressure sensors provide a measurement of the hydrogen gas pressure within the vessels and elsewhere in the hydrogen storage system. Because the pressure sensors employed in these types of systems need to provide a pressure measurement over a range of nearly 1000 bar, and they need to be relatively inexpensive, they typically have a tolerance band of about 1.5%, which gives an accuracy of +/−15 bar. Further, considering the measurement requirements of the sensor wiring over the entire temperature range that the vessels may encounter typically provides a measurement accuracy of +/−35 bar, which is added to the 20 bar minimum allowable pressure to provide the desired safety margin. Thus, in typical system designs, hydrogen discharge from the vessels needs to be stopped at a vessel pressure sensor reading of about 55 bar, resulting in about 5% of the hydrogen gas within the vessels not being usable for vehicle operation.
[0008] A method is needed for reliably protecting the pressure vessels from dropping below the minimum allowable pressure, but still allowing the most possible hydrogen gas to be consumed by the fuel cell. Such a method would allow the vehicle to be driven a greater distance between refueling events, thus improving customer satisfaction, while still protecting the vessels from dropping below the minimum allowable pressure.
SUMMARY OF THE INVENTION
[0009] In accordance with the teachings of the present invention, a method and system are disclosed for preventing gas pressure in a pressure vessel from dropping below a minimum allowable pressure. Pressure readings from a pressure sensor downstream of a pressure regulator are monitored by a processor as they vary within a steady fluctuation band under normal regulated pressure conditions. When the pressure regulator reaches a fully open position in low vessel pressure conditions, the processor detects a drop in the pressure reading to a value below the recent fluctuation band, and recognizes that the pressure is dropping below the regulation pressure value. The processor can use this information to shut off flow of gas from the vessel, thus preventing the vessel from dropping below its minimum allowable pressure, regardless of the actual magnitude of the pressure reading from the sensor—which can vary through a wide range due to tolerances.
[0010] Additional features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic diagram of a hydrogen storage system for a fuel cell;
[0012] FIG. 2 is a cross-sectional view of a pressure vessel used for hydrogen gas storage in the hydrogen storage system of FIG. 1 ;
[0013] FIG. 3 is a graph of gas pressure at three pressure sensors in the hydrogen storage system of FIG. 1 ;
[0014] FIG. 4 is a graph of pressure data from a pressure sensor as recorded in a system processor; and
[0015] FIG. 5 is a flow chart diagram of a method which can be used to shut down the hydrogen storage system in order to prevent the pressure in the vessels from dropping below a minimum allowable pressure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] The following discussion of the embodiments of the invention directed to a method and system for preventing a pressure vessel from dropping below a minimum allowable pressure is merely exemplary in nature, and is in no way intended to limit the invention or its applications or uses. For example, the disclosed methods and systems have particular application to a hydrogen storage system for a fuel cell vehicle, but may also be applicable to any gas storage or gas handling system.
[0017] FIG. 1 is a schematic diagram of a hydrogen storage system 10 for a fuel cell 34 . Pressure vessels 12 store hydrogen gas at a high pressure. More or fewer of the pressure vessels 12 could be used than the three shown in the hydrogen storage system 10 . A pressure sensor 14 measures the pressure at a filler line 16 which is used to fill the vessels 12 from an external supply (not shown). Shut-off valves 18 are situated just downstream from each of the pressure vessels 12 . The terms upstream and downstream are used throughout this disclosure with respect to the direction of hydrogen gas flow, with the fuel cell 34 being downstream of the pressure vessels 12 . A pressure sensor 20 measures the hydrogen pressure between the shut-off valves 18 and a pressure regulator 22 . The pressure regulator 22 is used to reduce the pressure of the hydrogen gas from the high pressure of the vessels 12 down to a lower pressure which is near that required by the fuel cell 34 .
[0018] A pressure sensor 24 measures the hydrogen pressure downstream of the regulator 22 and upstream of a shut-off valve 26 . The shut-off valve 26 can be closed to completely isolate the hydrogen storage system 10 from the fuel cell 34 . A second pressure regulator 28 is used to reduce the hydrogen gas pressure down to the low pressure required by the fuel cell 34 , which may be around 6 bar. Fuel supply line 30 connects the hydrogen storage system 10 to the fuel cell 34 . A controller 32 —in communication with the valves 18 , the sensors 14 , 20 , and 24 , the regulators 22 and 28 , the valve 26 , and the fuel cell 34 —can be used to monitor conditions in the hydrogen storage system 10 and the fuel cell 34 , and control the shutdown of the hydrogen storage system 10 if necessary to prevent the hydrogen gas pressure in the vessels 12 from dropping too low. For simplicity, the details of the fuel cell 34 are omitted, as are various filters, check valves, relief valves, and other components of the hydrogen storage system 10 .
[0019] The pressure of the hydrogen gas contained in the pressure vessels 12 can be as much as 700 bar or even higher. As a result, a high-range pressure transducer or sensor, typically with a range of about 900 bar, must be used for at least the pressure sensors 14 and 20 . The same type of sensor may also be used for the pressure sensor 24 . High-range sensors inherently have a high tolerance band around the pressure readings, which can significantly affect the accuracy of readings throughout their range. A typical pressure transducer or pressure sensor, such as the pressure sensor 14 which measures the pressure of the hydrogen gas in the vessels 12 , consists of a membrane and possibly several electronic components configured such that an output voltage signal is produced which is proportional to the pressure differential being experienced by the membrane. Each of the components of the sensor 14 has a base tolerance which can be represented as a plus or minus pressure variance. In addition, each of the components also experiences long-term drift, which further impacts the accuracy of the sensor 14 . When all of the tolerances of the components are added up, a typical high-range pressure transducer or sensor, such as the pressure sensor 14 , can have a pressure reading tolerance of +/−35 bar or higher.
[0020] FIG. 2 is a cross-sectional view of one of the pressure vessels 12 from the hydrogen storage system 10 . The vessel 12 includes an outer structural layer 40 , typically made of a carbon fiber composite material to provide structural integrity, and an inner liner 42 , typically made of a durable molded plastic, such as a high density polyethylene. An interior volume 44 contains the hydrogen gas. The liner 42 provides an impervious surface for containment of the hydrogen gas, and the outer layer 40 provides the structural integrity for the high pressures of the compressed hydrogen gas. The vessel 12 includes an adaptor (not shown) in an opening extending through the outer structural layer 40 and the inner liner 42 that provides access to the interior volume 44 for filling the vessel 12 and removing gas from the vessel 12 in a manner that is well understood to those skilled in the art.
[0021] The design of the pressure vessel 12 described above has proven to be reliable and cost effective. However, experience has shown that if the vessel 12 is initially pressurized with hydrogen gas, then the gas pressure is subsequently allowed to drop to a very low value, followed by a rapid re-pressurization, delamination of the inner liner 42 from the outer structural layer 40 can occur. In order to prevent this delamination, the hydrogen storage system 10 must be designed to prevent the pressure of the hydrogen gas in the interior volume 44 from dropping below a minimum allowable pressure value, typically about 20 bar in a common vessel design.
[0022] The high tolerance band on the pressure readings at the pressure sensor 14 , described above, makes it difficult to accurately determine how much hydrogen actually remains in the vessels 12 . This creates a problem when the pressure is nearing the minimum allowable pressure, as the hydrogen storage system 10 may need to be shut down prematurely in order to protect the vessels 12 . For example, the vessels 12 may have a minimum allowable pressure of 20 bar. If the pressure sensor 14 has a tolerance of +/−35 bar, then the minimum allowable pressure of 20 bar could possibly be reached when the pressure sensor 14 reads 55 bar (20 bar actual pressure plus 35 bar tolerance). Therefore, with a +/−35 bar tolerance around readings at the sensor 14 , the hydrogen storage system 10 would have to be designed to shut down when the pressure reading at the sensor 14 reaches 55 bar in order to protect the vessels 12 . However, due to the uncertainty of the pressure reading at the sensor 14 , the actual pressure remaining in the vessels 12 may be as high as 90 bar (the 55 bar reading plus the 35 bar tolerance) in such a situation. The result of all of this is that the hydrogen storage system 10 and the fuel cell 34 will have to be designed to shut down when, in most cases, a significant usable amount of hydrogen still remains in the vessels 12 .
[0023] It is possible to monitor other data in the hydrogen storage system 10 , besides the high-tolerance band pressure reading at the sensor 14 , to determine when the pressure in the vessels 12 is nearing the minimum allowable pressure. In particular, the pressure at the sensor 24 downstream of the pressure regulator 22 can be monitored to detect a pressure drop, which indicates that the regulator 22 is fully open. In a typical current design of the hydrogen storage system 10 , the regulator 22 has a regulation pressure slightly higher than the minimum allowable pressure of the vessels 12 . This means that, if the regulator 22 is fully open and the pressure downstream of the regulator 22 is dropping below the regulation pressure, then the pressure in the vessels 12 is getting very close to the minimum allowable pressure and the hydrogen storage system 10 must be shut down soon.
[0024] FIG. 3 is a graph 100 showing the pressure readings at the pressure sensors 14 , 20 , and 24 as the pressure in the hydrogen storage system 10 drops and the pressure regulator 22 fully opens. Horizontal axis 102 represents time, while vertical axis 104 represents pressure. Curve 106 is the pressure at the sensor 20 , just upstream of the regulator 22 . Curve 108 is the pressure at the sensor 24 , just downstream of the regulator 22 . Curve 110 is the pressure at the sensor 14 , upstream of the vessels 12 . At the left ends of the curves 106 , 108 , and 110 , it can be seen that the pressure at the sensors 14 and 20 is dropping, while the pressure at the sensor 24 is holding steady at the regulation pressure of the regulator 22 . Around the middle of the curves, at the time indicated by time mark 112 , the pressure at the sensor 20 , shown by the curve 106 , reaches the regulation pressure value. From this time onward, the regulator 22 is fully open, and the pressure at the sensors 20 and 24 are essentially the same. Meanwhile, the pressure at the sensor 14 is somewhat higher, due to pressure drops in the hydrogen storage system 10 caused by various check valves, pipes, and other components.
[0025] The regulation pressure value, indicated by pressure mark 114 , is about 29 bar in a typical implementation. The minimum allowable pressure in the vessels 12 is shown by line 116 . As mentioned above, the minimum allowable pressure, indicated by pressure mark 118 , is typically about 20 bar. The tolerance bands on the regulation pressure of the regulator 22 are shown by lines 120 and 122 . It can be seen by the relationship of the curves on the graph 100 that the full opening of the pressure regulator 22 can be used as an indication that the pressure in the vessels 12 is approaching the minimum allowable pressure, and that the hydrogen storage system 10 needs to be shut down soon to prevent further pressure drop. The mechanical tolerance band on the regulation pressure of the regulator 22 is much tighter than the combined mechanical and electrical tolerances of the sensors 14 , 20 , and 24 —especially when the analog to digital conversion tolerances at the controller 32 are taken into account. Therefore, it is possible to design a system shutdown strategy based on the regulation pressure of the regulator 22 which is essentially immune to the large tolerances of the pressure readings at the sensors 14 , 20 , and 24 .
[0026] In order to use the full opening of the regulator 22 as a trigger for shutting down the hydrogen storage system 10 to prevent dropping below the minimum allowable pressure, the inherent behavior of the pressure readings at the sensor 24 must be understood. FIG. 4 is a graph 130 showing the pressure signal from the sensor 24 as stored by the controller 32 . Just as with the graph 100 of FIG. 3 , horizontal axis 132 represents time, and vertical axis 134 represents pressure. Pressure trace 136 is the pressure reading at the sensor 24 as stored by the controller 32 . Thus, the graph 130 is essentially a greatly magnified version of the curve 108 on the graph 100 . On the graph 130 , the pressure trace 136 shows a fluctuation around a median value designated by the pressure mark 138 . This fluctuation is an inherent trait of the pressure readings as stored in the controller 32 , and this fact can be used as the basis of the control strategy of the present invention.
[0027] The controller 32 must monitor data from many different devices, perform numerous real-time calculations, and run many control algorithms simultaneously. Therefore, it is critical that memory space and computing power be allocated judiciously. In a typical implementation, the pressure readings from the sensors 14 , 20 , and 24 are stored in registers of only 8 bits in size. This means that the 900 bar range of the sensor 24 , for example, must be divided up between 2 8 (the number 2 raised to the power of 8) or 256 increments. 900 bar divided by 256 increments equals 3.5156 bar per increment, which is the pressure reading resolution in the controller 32 . This will be rounded to 3.5 bar/increment in this discussion for brevity. Returning attention to the pressure trace 136 on the graph 130 , the fluctuations above and below the median pressure value represent this phenomenon. That is, pressure mark 140 is 3.5 bar higher than the pressure mark 138 , and pressure mark 142 is 3.5 bar lower than the pressure mark 138 . Because of the tolerances in the sensor 24 , including its mechanical tolerances, analog-to-digital and digital-to-analog conversion tolerances, wiring resistance tolerances, and others, the analog voltage signal received by the controller 32 exhibits a slight variation, even when the regulator 22 is not fully open and the pressure at the sensor 24 is essentially constant. The slight variations in signal voltage from the sensor 24 are amplified by the 8-bit storage register resolution of the controller 32 , resulting in the real-world behavior shown by the pressure trace 136 .
[0028] While the fluctuation shown by the pressure trace 136 at first seems troublesome, the very predictable nature of the fluctuation can be used as the basis for a control strategy. It has been observed over years of actual usage of the hydrogen storage system 10 that the pressure trace 136 consistently remains within plus or minus one 3.5-bar increment of the median pressure value, as long as the regulator 22 is not fully open. Only when the regulator 22 reaches a fully open position, and the real pressure at the sensor 24 begins to drop below the regulation pressure, does the pressure trace 136 drop below the pressure shown by the pressure mark 142 . On the graph 130 , the regulator 22 reaches a fully open position and the pressure at the sensor 24 begins to drop, at the time designated by time mark 144 . After that time, it can be seen that the pressure trace 136 drops an additional 3.5 bar increment, down to a pressure designated by pressure mark 146 . A few time steps later, after some additional fluctuation, the pressure trace 136 drops to an even lower value. This behavior has been consistently observed in real implementations of the hydrogen storage system 10 , and is a reliable indicator that the regulator 22 is fully open and the pressure at the sensor 24 is dropping.
[0029] Line 148 on the graph 130 represents the minimum allowable pressure in the vessels 12 , which is typically about 20 bar. It is noteworthy that the minimum allowable pressure is sufficiently below the median pressure value, so that the pressure trace 136 can drop at least one 3.5-bar increment below the median value without crossing below the minimum allowable pressure. Also, it was shown on the graph 100 that, when the pressure readings at the sensors 20 and 24 reach the regulation pressure of the regulator 22 , the pressure at the sensor 14 is still somewhat higher. Thus, the pressure in the vessels 12 will not drop below the minimum allowable pressure, even if the pressure at the sensors 20 and 24 does drop slightly below the minimum allowable pressure.
[0030] Implementing a control strategy based on the phenomenon described above then becomes straightforward. FIG. 5 is a flow chart diagram 160 of a method which can be used to shut down the hydrogen storage system 10 in order to prevent the pressure in the vessels 12 from dropping below the minimum allowable pressure. At box 162 , a pressure increment value is defined, based on the range of the sensor 24 and the resolution of the data register in the controller 32 . As described in the examples above, a 900 bar pressure range and an 8-bit data register result in a pressure increment of 3.5 bar in the controller 32 . Thus, the pressure increment value will be known for any implementation of the sensor 24 and the controller 32 . At box 164 , the controller 32 monitors the pressure from the sensor 24 and identifies the fluctuation range within which the pressure is varying. At box 166 , the controller 32 calculates a rolling median pressure value for a certain time window. In one example, the time window is the past 60 seconds; however, longer or shorter windows could be defined as appropriate. The rolling median pressure value can be calculated by simply selecting the median (middle) value of the three different pressure readings which have most recently been recorded, as described previously and shown on the graph 130 . Other methods of calculating the rolling median pressure value could also be used.
[0031] With the rolling median pressure value established and the pressure increment value known, at box 168 the controller 32 can detect a pressure reading at the sensor 24 which is below the normal fluctuation range. The detection activity at the box 168 can be accomplished in one of two ways. First, the controller 32 can compare each new pressure reading with the previous reading to determine if the value has dropped by more than two pressure increments. A drop of two increments is possible under normal steady pressure conditions, as shown on the graph 130 . But a drop of more than two increments indicates that the pressure at the sensor 24 is actually dropping below the regulation pressure of the regulator 22 . Second, the controller 32 can compare each new pressure reading with the rolling median pressure value. If a pressure reading more than one increment below the rolling median pressure is detected, then the pressure at the sensor 24 is actually dropping below the regulation pressure of the regulator 22 . The two techniques for detecting a pressure below the normal fluctuation range may also be combined in a way that can accommodate a slight upward or downward drift of the fluctuation range during vehicle operation, without unnecessarily shutting down the hydrogen storage system 10 .
[0032] In the event that a pressure outside the normal fluctuation range is detected at the box 168 , the controller 32 commands a shutdown of the hydrogen storage system 10 at box 170 . The shutdown can most effectively be accomplished by closing the shutoff valves 18 , which are situated just downstream of the vessels 12 . By closing the shutoff valves 18 , the hydrogen gas contained in the pipes and components downstream of the valves 18 can be consumed by the fuel cell 34 before the fuel cell 34 stops producing electricity. In addition, the vehicle batteries will have at least a small amount of electrical charge remaining from fuel cell operation. The residual hydrogen gas and the residual electrical energy in the batteries will provide sufficient driving time for the driver to park the vehicle before it completely stops.
[0033] The shutdown sequence at the box 170 may also include a small time delay before closing the valves 18 . This is based on the fact that the pressure in the vessels 12 , represented by the reading of the sensor 14 , is known to be higher than the pressure at the regulator 22 , due to pressure drops therebetween. This fact can be used to allow a little additional time for the driver to park the vehicle upon being notified that the fuel cell 34 is shutting down imminently, while still preventing the vessels 12 from dropping below the minimum allowable pressure. The amount of time delay can be determined based on the known pressure drop between the sensors 14 and 20 , the capacity of the vessels 12 and the lines and fittings, and the rate at which hydrogen gas is being consumed.
[0034] It is emphasized that the specific values described above, including the 900 bar range of the sensor 24 , the 20 bar minimum allowable pressure, and the 8 bit storage register size, are all just examples. Higher or lower values could be used for any of these, but the operating principle of the detection and control strategy would remain the same.
[0035] In actual implementation, a low fuel warning would be issued to the driver of the vehicle well before the system shutdown procedure described above would have to be executed. The low fuel warning would be triggered by a pressure reading at the sensor 14 crossing below some threshold value, such as 80 bar, and most drivers would refuel their vehicle soon thereafter. As such, it is expected that the enforced system shutdown procedure would rarely have to be executed in real world driving situations. Nonetheless, the enforced system shutdown based on a pressure drop at the sensor 24 , as disclosed herein, can provide an extra measure of protection for the reliability of the vessels 12 . In doing so, it also avoids shutdown of the hydrogen storage system 10 when a significant amount of usable fuel still remains in the vessels 12 , thus allowing the greatest possible driving range of the vehicle between refueling stops.
[0036] The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
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A method and system for preventing gas pressure in a pressure vessel from dropping below a minimum allowable pressure. Pressure readings from a pressure sensor downstream of a pressure regulator are monitored by a processor as they vary within a steady fluctuation band under normal regulated pressure conditions. When the pressure regulator reaches a fully open position in low vessel pressure conditions, the processor detects a drop in the pressure reading to a value below the recent fluctuation band, and recognizes that the pressure is dropping below the regulation pressure value. The processor can use this information to shut off flow of gas from the vessel, thus preventing the vessel from dropping below its minimum allowable pressure, regardless of the actual magnitude of the pressure reading from the sensor—which can vary through a wide range due to tolerances.
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This is a divisional of application Ser. No. 243816, filed Sep. 13, 1988 now U.S. Pat. No. 4,966,663.
FIELD OF THE INVENTION
This invention relates to the fabrication of silicon membranes and, particularly, to a method of fabrication wherein stress levels within the membrane may be carefully controlled.
BACKGROUND ART
Thin membranes of single crystal silicon are useful in a wide variety of applications. Some such applications include masks for X-ray lithographic exposures or integrated circuits, shadow or channeling masks for particle beams (such as ions or electrons), windows for atmospheric isolation, deformable optical and mechanical elements, sensors and transducers, and substrates for the fabrication of semiconductor devices.
Silicon wafers are conventionally produced by slicing thin discs of material from monocrystalline ingots. The discs are then thinned and polished using well known chem-mechanical grinding and polishing techniques. Wafers are commercially available in thicknesses ranging from 0.003 inches and up, with typical thicknesses being 0.015-0.025 inches. Below 0.003 inches in thickness, the chem-mechanical thinning techniques do not yield good results, and alternative chemical etching techniques are applied. Typically, the entire wafer is not thinned down since the result would be too fragile to handle. Instead, only portions of the wafer are thinned. The portions of the wafer which are not to be thinned are covered with an inert masking layer which protects such portions from the etching solution. The resultant structures, formed from chemically thinned silicon wafers, are referred to as membranes to distinguish them from the starting wafer material. These membranes are useful for applications that require thicknesses of silicon below that which can be achieved by chem-mechanical polishing, i.e. below approximately 0.003 inches.
The simplest procedure for forming a membrane from a silicon wafer is by a time down etching technique. In this process, the wafer is first covered with a masking layer on those portions of the wafer where etching is not desired. The wafer is then immersed in the etching solution, which begins to remove silicon from the unmasked areas. If the etch rate of the silicon in the solution being used is known, and if the etch rate is uniform over all areas of the wafer being etched, then the wafer can simply be immersed in the solution for the amount of time appropriate to reduce the wafer thickness to whatever is desired. The main drawbacks to this technique are that precise control of the etch rate and maintenance of high uniformity are difficult to achieve.
To solve the control problems associated with the time down approach, a variety of etch-stop techniques have been developed. The most commonly used technique is the p++ etch-stop. This technique relies on the fact that the etch rate of silicon in alkaline solutions drops substantially when the doping level of boron exceeds about 5×10 19 per cm 3 . This technique has been described in U.S. Pat. No. 4,256,532 issued to Magdo, et al and in U.S. Pat. No. 4,589,952 issued to Behringer, et al. Use of this technique to create masks suitable for use with masked ion beam lithography is described by G. M. Atkinson, et al, "A Minimum Step Fabrication Process for the All-Silicon Channeling Mask, " Journal of Vacuum Science Technology, January/February 1987, pp. 219-222.
To form a membrane by the p++ etch-stop technique, a boron doped layer is formed on one surface of the silicon wafer. The wafer is then etched down starting from the other side. When the etching solution reaches the interface defined by the boron doped layer, the etching effectively stops due to the drop in etching rate. The thickness of the resulting membrane is then determined by the thickness of the boron doped layer. Since the maximum solubility of boron in silicon is about 1×10 20 per cm 3 , this means that the boron doping level of the completed membrane must be in the range of approximately 0.5-1×10 20 per cm 3 . A similar technique for fabricating a membrane by preferentially etching n+ silicon is disclosed in U.S. Pat. No. 3,713,922 issued to Lepselter, et al.
An alternative etch-stop technique is the p/n electrochemical etch-stop (ECE). In this case, a p/n junction is formed in the silicon wafer. Several well-known techniques for doing this are diffusion, ion implantation and epitaxy. By the application of an appropriate electrical voltage to the wafer, the etching of the silicon can be made to stop at the interface defined by the p/n junction. The thickness of the membrane is then determined by the location of the p/n junction.
The ECE technique is generally described by H. A. Waggener, "Electrochemically Controlled Thinning of Silicon," The Bell System Technical Journal, March, 1970, pp. 473-475. Enhancements to the original technique as described by Waggener include the use of other alkaline etchants to replace KOH (see T. N. Jackson, et al, "An Electrochemical P-N Junction Etch-Stop for the Formation of Silicon Microstructures," IEEE Electron Device Letters, Vol. EDL-2, No. 2, February 1981, pp. 44-45 and M. Hirata, et al, "A Silicon Diaphragm Formation for Pressure Sensor by Anodic Oxidation Etch-Stop," IEEE Conference Proceedings of Transducers 1985, June 1985, pp 287-290), and the use of multi-electrode biassing schemes (see U.S. Pat. No. 4,664,762 issued to Hirata and B. Kloek, et al, "A Novel Four Electrode Electrochemical Etch-Stop Method for Silicon Membrane Formation," IEEE Conference Proceedings of Transducers 1987, June 1987, pp. 116-119). The ECE technique can be used to produce large area membranes with good uniformity and precise thickness control.
Stress control is of importance in many membrane applications. As an example, a membrane with high tensile stress is desirable for X-ray masks. This permits the membrane to be made as flat as possible and improves its resistance to distortion when metal absorber patterns are applied to one surface. For shadow masks, a membrane of low but non-zero tensile stress is optimum. This keeps the membrane flat and but minimizes any distortion when the stencil holes are created.
The response of a membrane to a differential pressure across its two surfaces is also affected by its stress level. This is of importance in the use of membranes as windows or in some sensor applications. The resistance of the membrane to breakage due to mechanical vibrations, shocks or forces is also influenced by stress levels. Semiconductor device performance is also often a function of stress levels in the silicon material. Therefore, the suitability of a membrane for use in a semiconductor device would also be influenced by the membrane stress.
Several studies have been done on the effect of dopants on the stress levels in silicon wafers (see M. Sasiki, et al, "A Study of Strain in Ion Implanted Silicon," Semiconductor Processing, ASTM STP 850, American Society for Testing and Materials, 1984, pp. 96-109; N. Sato, "X-Ray Measurement of Lattice Strain Induced by Impurity Diffusion," Journal of the Physial Society of Japan, Vol. 38, No. 1, Jan. 1975, pp. 202-207; and K. Yagi, et al, "Anomalous Diffusion of Phosphorus into Silicon," Japanese Journal of Applied Physics, Vol. 9, No. 3, March 1970, pp 246-254). These studies have been related to the effects of any stress on the properties of the diffusion or implanted layer. In these studies X-ray analysis of doped wafers was performed to measure lattice strain for various dopant types and concentrations. This shows that the amount of strain induced depends on the size of the dopant atom. Boron and phosphorus, which are smaller than silicon, add tensile strain. Arsenic, which is almost the same size as silicon, adds only a small compressive strain. Larger atoms such as antimony add compressive strain. The strain increases with increasing dopant concentration until a maximum limit is reached. At this point, dislocations are created. Any additional dopant added at this point just causes more dislocations to be formed, rather than increasing the stress further. The aforementioned studies relate only to the effect of stress in bulk wafers, and do not discuss the implications of this physical effect for membrane fabrication.
SUMMARY OF THE INVENTION
One of the objects of this invention is to take advantage of a previously unrealized property of the ECE technique to produce membranes with controlled stress characteristics. This is accomplished by controlling the dopant species, the total dopant dose, and the dopant concentration profile.
A silicon membrane is formed by doping a silicon substrate to create a doped layer equal in thickness to the desired thickness of the membrane. The dopant species is selected according to whether tensile or compressive stress is desired. Atoms smaller than silicon are used to create tensile stress, whereas atoms larger than silicon are used to create compressive stress. The dopant concentration is then controlled to establish a predetermined level of stress in the doped layer. The dopant concentration may be uniform to establish isotropic stress within the membrane or many have a concentration profile in any one or more dimensions to establish a desired anisotropic stress pattern within the membrane.
After creation of the doped layer, a membrane is formed by etching away the silicon substrate beneath the desired area of the membrane using the electrochemical etch stop technique.
Post-etch adjustment of stress characteristics may be accomplished by introducing additional dopant of the same or a different species.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1a-1e are schematic representations of sequential processing steps that may be used to form a silicon membrane using the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A method for fabricating a silicon membrane with predetermined stress characteristics is disclosed. In the following description, for purposes of explanation and not limitation, specific numbers, dimensions, materials, etc. are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
Referring first to FIG. 1a, the method of the present invention begins with a silicon wafer 10, either n or p- type depending on the dopant selected. A p-type wafer is used for n-type dopants and a n-type wafer with p-type dopants.
As shown in FIG. 1b, a doped layer 12 is formed using any of the standard doping techniques as are well known in the art (i.e. diffusion, ion implantation, or epitaxy). The selection of the dopant specie depends on the application and the stress level desired. Boron or phosphorus are suitable for achieving tensile stress, whereas antimony or tin are suitable for compressive stress. Arsenic, having an atomic diameter nearly equal to that of silicon, is useful for very low stress levels. The invention is not limited to these species, but comprehends any other atom with which a doped layer can be formed. The atoms named above constitute the common dopant atoms used in semiconductor manufacturing.
The stress level of the membrane is determined by the total dose of dopant added to the wafer, as given by the following formula:
σ=β[E/(1-ν)](D/t) (1)
Where:
The membrane stress is denoted by σ,
β is the lattice contraction coefficient (which depends on the dopant species used),
E and ν are elastic constants of silicon, namely Young's modulus and Poisson's ratio respectively,
D is the total dose in atoms per cm 2 , and
t is the membrane thickness.
The relationship expressed in equation (1) holds true as long as the stress remains below the level required to create dislocations. Furthermore, it will be understood that any additional extraneous sources of stress, such as atomic impurities or crystalline defects in the silicon, must be maintained at low levels. Equation (1) also assumes that the unetched portions of the silicon wafer are sufficiently rigid to prevent any warping of the structure.
The quantity (D/t) in equation (1) will be recognized as the average dopant concentration in the membrane. The formula shows that for a given specie, the range of stress levels possible is determined by the range of dopant concentrations possible. Recall that the ECE technique does not depend on the use of a particular dopant species or a narrow range of dopant concentrations as does the p++ etch-stop or other etching techniques. Therefore, the ECE technique is particularly well-suited for the making of stress controlled membranes.
Equation (1) above gives the expression for the average stress of the total membrane. In certain applications it is desirable to control not just the total stress in the membrane, but also the stress profile. As an example, one might want to make a membrane with the stress higher on one surface than on the other. This can be accomplished by depositing the dopant in such a way that its concentration is higher on one surface than the other. If the dopant concentration profile is not uniform throughout the membrane, then the stress will vary locally as determined by the local dopant concentration. The local stress (as a function of z=depth into the membrane) is given by the expression:
σ(z)=β[E/(1-ν)]C(z) (2)
Where C(z) is the dopant concentration as a function of depth and all other variables are as defined for equation (1).
After the doped layer 12 is formed as described above, suitable masking 14 is applied to the substrate as shown in FIG. 1c. Masking 14 covers the entire surface 13 of doped layer 12 and those portions of opposite surface 15 except for the membrane area. The membrane 16 is then formed by etching the substrate underlying the membrane area using the well known ECE technique as illustrated in FIG. 1d. After etching is completed, masking 14 is removed by a solvent or other suitable means as shown in FIG. 1e.
After making the membrane 16, it is possible to adjust the stress level by the addition of more dopant atoms. This step can also be used with etch-stop techniques other than the ECE technique to adjust membrane stresses after the membranes are formed.
Yet another aspect of the invention is that it is also possible to vary the stress levels at different lateral locations on the wafer. Using standard doping techniques, it is possible to introduce different dopant species or obtain different dopant concentrations in different areas on the wafer. Therefore it is possible to form membranes with different stress levels on the same wafer, or to form a single membrane with stress that varies as a function of lateral position on the membrane.
EXAMPLES
1. A membrane of the thickness 2.8 microns was formed using a p-type silicon wafer diffused with phosphorus for a total dose of 3.8×10 15 atoms/cm 2 . The measured stress was found to be 6.1×10 7 dynes per cm 2 . The predicted value based on equation (1) is 6.0×10 7 . This is based on using values of 1.5×10 12 dynes/cm 2 and 3.0×1.0 -24 cm 3 /atom for the quantities E/(1-ν) and β respectively.
2. A membrane of thickness 2.2 microns was formed using a p-type wafer with a phosphorus ion implant of 1.0×10 14 atoms/cm 2 . The measured stress was below resolution limits of the equipment used for measurement (below 5×10 6 dynes/cm 2 ). This is consistent with the predicted value of 2.0×10 6 .
3. A membrane of thickness 2.6 microns was formed using a p-type wafer with a phosporus ion implant of 1.0×10 16 atoms/cm 2 . The measured stress was 1.3×10 8 dynes/cm 2 compared with a predicted value of 1.7×10 8 .
It will be recognized that the above described invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the disclosure. Thus, it is understood that the invention is not to be limited by the foregoing illustrative examples except as set forth in the appended claims.
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A method for fabricating a silicon membrane with predetermined stress characteristics. A silicon substrate is doped to create a doped layer as thick as the desired thickness of the membrane. Stress within the doped layer is controlled by selecting the dopant based on its atomic diameter relative to silicon and controlling both the total concentration and concentration profile of the dopant. The membrane is then formed by electrochemically etching away the substrate beneath the doped layer.
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FIELD OF THE INVENTION
[0001] This invention relates to suction inlet valves for fire truck pumpers. More particularly, this invention relates to suction inlet valves for fire truck pumpers usable in both hydrant and drafting operations.
BACKGROUND ART
[0002] Fire companies utilize pumper trucks to increase the pressure of hydrant water flowing through fire hoses and to pressurized water from drafting tanks. Pumpers draw water through suction valves from sources such as portable water tanks or fire hydrants.
[0003] Illustrative of widely used suction inlet valve are the Pre-Con valves available from Hydra-Shield Manufacturing, Inc. of Irving, Tex., covered by U.S. Pat. No. 5,178,183. The Pre-Con valve is designed to operate as an automatic flow control valve which eliminates the need for manual adjustments in reaction to water flow. In hydrant operations, the Pre-Con valve automatically opens in proportion to the flow demand and is capable of automatically balancing flow between multiple water sources. The Pre-Con valve's automatic check valve action also minimizes water hammer. When drafting from a source of water, such as a portable water tank, the check valve action of the Pre-Con valve holds prime water when flow is stopped and allows switching to a booster tank and back to drafting without flow interruption. The Pre-Con valve is an improvement over butterfly valves which it has replaced in many situations.
[0004] Pre-Con valves have continued to improve over the years with current configurations having follower-in-slot cam operators rather than external profile cam operators. It has been found that these current configurations have a tendency to freeze in cold weather which can render the valve and associated equipment at least temporarily useless in cold weather.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to an inlet suction valve use with pumper fire trucks. The inlet suction valve comprises a valve housing having a male body portion defining a first cavity and a female body portion defining a second cavity, the body portions are joined with the cavities forming a chamber. A first coupling is provided on the male body portion for coupling with a source of water and a second coupling is provided on the female body member for coupling with a pumper boaster tank on the fire truck. A valve element is disposed in the first cavity and is seated against a valve seat located adjacent to the first coupling. A valve support with an axial hole therethrough is disposed between the first and second cavities of the male and female bodies. The valve support has openings therethrough allowing water to flow freely from the first cavity to the second cavity. A valve stem is connected to the valve element and extends back through the first cavity and the axial hole in the valve support to the second cavity. A cam block is located on the calve stem and has a slot extending therein laterally with respect to the axis of the valve stem. A valve operating shaft extends from outside the housing to the cam block, the valve operating shaft having a crank arm extending laterally therefrom with a projection thereon that is spaced from the axis of the valve operating shaft. The projection is received in the slot in the cam body. A valved drain extends through the female valve body and in to the second cavity to drain water away from the cam body to avoid frozen water from clogging the slot and preventing operation of the valve.
[0006] In a further aspect of the invention, an operating handle projects from the operating shaft.
[0007] In still a further aspect of the invention, the operating handle is a lever and a lateral hole formed through a portion of the support to receive the operating shaft therethrough. The inlet suction valve is made substantially of metal and lubricant disposed around the valve stem and operating shaft.
[0008] In still a further aspect of the invention, a valved vent outlet is disposed on the male body member and is connected by a bore through the male body member to the first coupling at a location in front of the valve element. The valved vent outlet on the male body member is located at the bottom of the female housing directly adjacent to the water drain on the female body member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0010] FIG. 1 is a schematic view showing a suction inlet valve of the instant invention drafting water from a portable water tank;
[0011] FIG. 2 is a schematic illustration showing use of a suction valve according to the instant invention being used with a fire hydrant;
[0012] FIG. 3 is a side elevation of the suction inlet valve according to the present invention;
[0013] FIG. 4 is a top elevation taken along lines 4 - 4 of FIG. 3 , and
[0014] FIG. 5 is an exploded view of the suction inlet valve of FIGS. 3 and 4 .
DETAILED DESCRIPTION
[0015] Referring now to FIG. 1 , a suction inlet valve designated by the numeral 10 and configured in accordance with the principles of the instant invention, is disposed at the end of a suction pipe 12 used in a drafting operation. The suction pipe 12 is connected by a line 14 to a pumper booster tank 16 within a pumper firetruck (not shown). At its inlet end the suction valve is connected by a suction hose 18 to a source of water, such as a portable water tank 20 . A pump discharge manifold 22 is connected to fire hoses 24 at either or both ends. Upon opening a booster tank valve 26 , water is forced at elevated pressure through the fire hoses 24 .
[0016] After the pump in the firetruck (not shown) is primed and activated, the suction inlet valve 10 automatically opens at about 8 to 10 inches of vacuum if set in an automatic mode. Normally, the suction inlet valve 10 automatically opens or closes in proportion to the volume of water flow.
[0017] If the water level in the tank 20 gets too low, the booster valve 26 is opened to decrease the flow resistance from the booster tank 16 allowing the suction inlet valve 10 to automatically close and thereby hold prime water in the suction hose 18 . When the water level in the portable tank 20 is restored, the booster valve is closed so as to create a vacuum in the pump which automatically opens the suction inlet valve 10 .
[0018] If it is desired to utilize the pumper booster tank 16 as an emergency reservoir, the suction inlet valve 10 allows the operator to switch from drafting from the portable water tank 20 to drafting from the booster tank 16 without disrupting water flow through the fire hoses 24 . In the event that all discharge lines 24 are shut off, the suction inlet valve 10 automatically closes to hold prime in the suction hose 18 .
[0019] From the above discussion, it is seen that the suction inlet valve 10 is critical to proper operation of a pumper firetruck. In order to tune the system to particular situations, it is advantageous to have the capability of manually adjusting the amount that suction inlet valve 10 opens.
[0020] Referring now to FIG. 2 where similar elements have the same reference numerals, a pumper truck is schematically shown working from a fire hydrant 28 . When the hydrant 28 is turned on, water pressure automatically opens the suction inlet valve 10 if the valve has been manually adjusted for automatic operation. The suction inlet valve 10 opens at approximately 5 psi and will open in proportion to the flow demand. When flow is shut off through the pump discharge line 22 , the suction inlet valve 10 automatically closes and, due to its novel configuration, reduces the water hammer effect in the suction hose 18 and fire hydrant 28 . If it is desired to provide water from an auxiliary source, an additional inlet suction valve 10 ′ can be connected to the opposite end of pump suction line 12 .
[0021] When working from a fire hydrant 28 , it is advantageous to provide for automatic operation of the suction inlet valve 10 , which automatic operation can be adjusted and if necessary, overridden. This is especially so when there are pair of suction inlet valves 10 connected to the same pump suction line 12 . As will be explained in detail hereinafter, the suction inlet valve 10 has a control handle which determines the setting of automatic flow control pumper suction inlets. In its automatic mode, the valve 10 automatically opens or closes in response to flow demand. As more discharge lines are opened from a pumper truck, or if nozzle flows increase, the valve 10 automatically opens to the limit of the control handle setting. If flow is reduced, the valve 10 automatically closes proportionally and when flow is stopped, the valve closes completely. Automatic adjustment and operation is particularly important in reducing the effects of water hammer caused by abruptly shutting off a nozzle attached to a fire hose 24 .
[0022] The valve 10 also functions as a one way flow valve. During fire hydrant operations ( FIG. 2 ), high pressure water sources which occur during operations such as pump relay operations, are prevented by the valves 10 from overriding low pressure water sources. Moreover, multiple inlets with the valves 10 can be used to balance the water flow from several different sources. When used in the drafting mode of FIG. 1 , the automatic check valve action of valve 10 holds prime water in the suction hose 18 when flow is stopped. This is very important because the system does not have to reprimed to restart the pumping operation.
[0023] With the foregoing background in mind, a particular structure of the valve 10 suitable for providing automatic operation which is manually adjustable is set forth in FIGS. 3-5 . Referring first to FIG. 3 , it is seen that the valve 10 has an operating lever 29 which selectively sets the mode to a fully “closed” mode, a fully “open” mode or a setting selected therebetween. The valve 10 opens automatically at any setting other than fully closed mode, however, the volume of flow is reduced at settings other than the fully open mode.
[0024] Referring now also to FIGS. 4 and 5 as well as FIG. 3 , the vlave 10 comprises a male body portion 30 which has a threaded neck 32 onto which is threaded a suction hose such as the suction hose 18 of FIGS. 1 and 2 . The neck 32 has a mouth 34 therein into which water flows. The water may be under pressure, such as the pressure applied from the fire hydrant 28 of FIG. 2 , or may be unpressurized if provided by a source such as the portable water tank 20 of FIG. 1 . The male body member 30 has a first cavity 36 with an annular substantially flat area 38 which joins the cavity 36 to the mouth 34 . As is seen in FIG. 5 , the male body member 30 may have alternate configurations 30 ′ and 30 ″ with Storz couplings 39 ′ and 39 ″, respectively.
[0025] Attached to the male valve body 30 , is a female valve body 48 with a second cavity 49 therein. A plurality of bolts 50 are received through threaded bores 52 in an annular flange 54 around the periphery of the female body member 48 . The female body member 48 has a neck 56 which has rotatably mounted thereon a threaded collar 60 which has internal threads 64 . The threads 64 of the portable collar 60 threadably receive male fittings on the suction pipes 12 of FIGS. 1 and 2 . In order to ensure a leakproof seal, a gasket 66 abuts the end of the neck 56 and is loosely received in an annular groove within the collar 60 . Since the gasket 66 may be subject to considerable wear, it is readily replaceable.
[0026] The cavity 36 of the male valve body 30 and the cavity 49 of the female valve body 48 cooperate to define a chamber 72 . Projecting radially inward into the chamber 72 from the female valve body 48 is a support ring 74 that includes three struts 75 , 76 and 77 extending inwardly from an annular flange 79 that has an annular lip 80 with holes 81 therethrough. The bolts 50 which extend through the male and female bodies 30 and 48 pass through the holes 81 to retain the support 74 in the chamber 72 while separating the cavities 36 and 49 from one another.
[0027] A valve operating shaft 85 connected to the operating handle 29 extends through a bore 86 in a pedestal 87 on the strut 75 . The valve operating shaft 85 has a crank arm 88 fixed to the bottom end 89 thereof. The crank arm 88 has a pin 90 aligned with an axis 91 spaced from the axis 92 of the valve operating shaft 85 . The pin 90 registers with a slot 95 in a cam body 97 . Preferably, the pin 90 drives a slide block 98 in the slot 95 . The slide block 98 is retained on the pin 90 by a slide block retainer 99 . A valve stem 100 is fixed to the cam body 97 and passes through a bore 102 in the support ring 74 . The valve stem 100 is slidably received in a bore 103 through a cone-shaped valve element 104 and is axially adjusted with a set screw 105 in a threaded portion of the bore 103 . A coil spring 106 extends between the support 74 and the valve element 103 to bias the valve element 103 to a closed position against an annular valve seat 107 on the annular flat portion 38 .
[0028] Upon rotating the shaft 25 in the counter clock wise direction with respect to FIG. 4 , the pin 90 slides laterally in the slot 95 extending in the cam body 97 . As the pin 90 slides laterally in the slot 95 , the pin draws the valve stem 100 back through the bore 103 against the bias of the spring 106 to pull the cone-shaped valve element 104 away from the annular valve seat 107 .
[0029] There are some situations in which it is advantageous to manually adjust automatic operation of the floating valve element 103 instead of just letting the valve element float.
[0030] The valve 10 is usually left mounted on the fire truck so that there is a tendency for the valve to freeze and become useless in cold weather. This is especially a problem with the aforedescribed configuration where an operating handle 29 is rigidly connected to and operating shaft 85 that is in turn integral with a crank arm 88 and pin 90 because the pin 90 conducts heat rapidly away from the slot 95 in the cam body 97 . Consequently, if there is water in the slot 95 , the water can rapidly freeze in the slot blocking lateral movement of the pin 90 in the slot. If lateral movement of the pin 90 is blocked then the valve element 104 can not be unseated from the valve seat 107 and the valve 10 becomes useless. If the fire truck is racing for several miles through very cold air which flows over the handle 29 , heat is conducted even more rapidly away from the pin 90 . If the pin 90 and slot 95 are immersed in water, water in the slot may freeze thus blocking movement of the pin in the slot even if other retained water in the cavity is not yet frozen.
[0031] In order to prevent frozen water from blocking operation of the valve 10 , a water drain 120 ( FIG. 4 ) with a rotating stop cock valve 121 is positioned at the bottom 122 of the cavity 49 of the female body 48 . Another advantage of draining the chamber is that corrosion on the walls of the chamber and on parts of the cam operating mechanism is reduced. The water drain 120 is positioned in the bottom of the cavity 49 in female body 48 because another fluid vent or drain 130 operated by a stop cock valve 132 is positioned on the bottom 133 of the male body 30 . The fluid vent or drain 130 is connected by a bore 134 to the mouth 34 of the threaded neck 32 and relieves excess pressure on the cone-shaped valve element 104 .
[0032] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
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A suction inlet valve for fire truck pumpers has a male body portion and a female body portion, the portions defining a chamber therein. A cone-shaped valve element is connected to a valve stem which has a cam body thereon with a cam slot therein. The cam slot receives a projection from an operating shaft which projects out of the housing. The operating shaft has an operating handle thereon which is exposed to the environment and conducts heat from the chamber. If there is water in the chamber, there is an increased chance of water in the cam slot freezing disabling operation of the valve. To drain water away from the cam slot, a drain is provided in the male body portion for draining water from the chamber.
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BACKGROUND OF THE INVENTION
The present invention relates to a foam injection molding method wherein high-expansion ratio foaming is effected in a mold. More particularly, the present invention relates to a foam injection molding method wherein high-expansion ratio foaming is effected in a mold under control by expanding and contracting the cavity, while keeping it closed, by moving a mold element.
Plastics can be given various properties by foaming them. Particularly, the following various properties can be imparted to plastics by foaming: heat insulating, sound absorbing, vibration damping, buoyant, elastic, lightweight, liquid guiding, dust-resistant (filtering), friction and non-slip properties. Many foam moldings have recently been employed for various purposes by making use of these properties. It is expected that there will be an increase in the demand for composite moldings incorporating a foamed molded part in a part thereof to utilize the above-described properties.
At present, foaming is carried out mainly by injection molding and extrusion. Injection molding, which is superior to extrusion in moldability, is a method wherein a relatively small amount of molding material containing a blowing agent is injected into a cavity in a mold under low pressure, and the cavity is filled with the molding material by foaming caused by the blowing agent. As the blowing agent, a low-boiling point petroleum solvent may be used, but an azodicarbonamide or oxybissulfonyl hydrazide compound is generally employed.
Such a foam injection molding method has difficulty in controlling the amount of molding material injected because the molding material is foamed in the cavity with a fixed volumetric capacity to fill it. Accordingly, moldings produced by foaming are generally low-expansion ratio molded parts; no molded parts of high-expansion ratio can be obtained by the above-described injection molding method.
FIGS. 1(a) and 1(b) show a known high-expansion ratio injection molding method. As shown in FIG. 1(a), the conventional injection molding method employs an injection mold composed of two mold elements, i.e., a stationary mold element 01 and a movable mold element 02. The movable mold element 02 is slidable relative to the stationary mold element 01. As shown in FIG. 1(a), an initial cavity 03 is formed by the two mold elements 01 and 02. The initial cavity 03 is rapidly filled with a molding material containing a blowing agent. Immediately after the filling process, the movable mold element 02 is moved backward relative to the stationary mold element 01 to enlarge the cavity volume, thereby forming a final cavity 04 as shown in FIG. 1(b).
The charged molding material is foamed in the expanded cavity 04, formed as described above. This foam injection molding method enables the expansion ratio to be increased. In other words, the described foam injection molding method enables high-expansion ratio foaming.
If the mold is cooled immediately after the charging of the molding material, the material that is present at the interface between the cavity and the mold inner surface is immediately cooled. When the material at the interface is rapidly cooled, a skin is formed on the foaming material molded, and a relatively lightweight molded part having a skin layer is obtained. Such foam moldings, in which the interior is protected by the skin layer, can be utilized as products or materials which have various properties.
The above-described conventional method, in which the cavity is expanded by moving two mold elements relative to each other to effect high-expansion ratio foaming, suffers, however, from the following two problems: The interfaces a and b of the cavity expansion that is added to the initial cavity, that is, the cavity portion that remains when the initial cavity, which is shown in FIG. 1(a), is subtracted from the final cavity, which is shown in FIG. 1(b), are limited to surfaces S, as shown in FIG. 2, which are formed by scanning movement of the line L of intersection of the cavity forming surface A of the stationary mold element 01 and the cavity forming surface C of the movable mold element 02 having a sliding surface B that slides on the cavity forming surface A. Accordingly, the degree of freedom of the final shape that can be given to the foamed part is limited to a considerably low level.
More generally, when only two mold elements are employed, it is impossible to have a cavity interface that disables the initial cavity 03, which is formed by the two mold elements, from being shifted to the final cavity 04 by moving the two mold elements relative to each other while keeping the cavity closed.
A cavity interface with which the initial cavity 03 cannot be shifted to the final cavity 04 with the cavity kept closed is such that a portion of the cavity forming surface A in the vicinity of the line L of intersection of the two cavity forming surfaces A and C of the two mold elements 01 and 02, which form the closed cavity 03 when they are joined together, is formed from a surface that is not parallel to the direction of movement of the two mold elements 01 and 02.
Since the foam injection molding method that employs only two mold elements suffers from the above-described restriction, it is impossible to form three-dimensional molded parts of high-expansion ratio whose interfaces have neither parallel sliding surfaces nor a surface consisting of a set of parallel lines, for example, a spherical part having a spherical interface, an annular part, such as a doughnut-shaped part, which has a torus interface, a polyhedron, such as a regular tetrahedron, in which any two of the four interfaces are not parallel to each other, a conical part, or a complicated three-dimensional part, such as a tetrapod, which consists of a combination of a plurality of conical surfaces, although it is possible to form a three-dimensional object, e.g., a circular cylinder, which has an interface consisting of a set of parallel lines, by a high-expansion ratio injection molding process. This is the first problem of the conventional method.
Molded parts produced by high-expansion ratio foaming extremely vary in the physical properties according to the bubble size distribution and porosity. In the high-expansion ratio foaming process that is carried out by expanding the cavity, various factors, such as the pressure and temperature in the cavity, the viscosity of the molding material to be foamed, and the shape of the cavity, particularly have effects on the uniformity of dispersion of bubbles generated and the bubble size distribution characteristics. It is not easy to control the uniformity of dispersion of bubbles and the bubble size distribution characteristics by using only the ratio of the volume of the initial cavity to the volume of the final cavity and the cavity expanding time. This is the second problem of the conventional method.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a cavity expanding and contracting foam injection molding method which enables physical properties of a high-expansion ratio molded part to be properly drawn out by physically controlling foaming when the cavity is expanded.
It is another object of the present invention to provide a cavity expanding and contracting foam injection molding method which enables physical properties of a high-expansion ratio molded part to be properly drawn out by physically controlling foaming when the cavity is expanded, and which makes it possible to form high-expansion ratio molded parts having various shapes with a high degree of freedom of interfacial configuration.
To attain the above-described objects, the present invention provides a foam injection molding method including the steps of: forming a closed initial cavity (8) by using at least two mold elements (1 and 3) which are movable relative to each other; charging a molding material into the initial cavity (8) formed by the cavity forming step; forming an intermediate cavity having a volumetric capacity different from that of the initial cavity (8) by moving one (3) of the two mold elements (1 and 3) relative to the other mold element (1) while keeping the cavity closed, which is formed by the two mold elements (1 and 3); and forming a final cavity (9) having a larger volumetric capacity than that of the initial cavity (8) by moving one (3) of the two mold elements (1 and 3) relative to the other mold element (1) while keeping the cavity closed, which is formed by the two mold elements (1 and 3), and foaming the charged molding material in the final cavity (9), thereby forming a foam injection-molded part.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, in which like reference numerals denote like elements, and of which:
FIGS. 1(a) and 1(b) are sectional views showing a known foam injection molding method;
FIG. 2 is an oblique projection for explanation of the restriction on the cavity formation by the known foam injection molding method;
FIG. 3 is a sectional view showing a fundamental arrangement of the cavity expanding and contracting foam injection molding method according to the present invention as a first embodiment;
FIG. 4 is a sectional view showing a first step of the first embodiment;
FIG. 5 is a sectional view showing a second step of the first embodiment;
FIG. 6 is a sectional view showing a third step of the first embodiment;
FIG. 7 is a sectional view showing a fourth step of the first embodiment;
FIG. 8 is a sectional view showing a fundamental arrangement of the cavity expanding and contracting foam injection molding method according to the present invention as a second embodiment;
FIG. 9 is a sectional view showing a first step of the second embodiment;
FIG. 10 is a sectional view showing a second step of the second embodiment;
FIG. 11 is a sectional view showing a third step of the second embodiment;
FIG. 12 is a sectional view showing a fourth step of the second embodiment;
FIG. 13 is a sectional view showing a fundamental arrangement of the cavity expanding and contracting foam injection molding method according to the present invention as a third embodiment;
FIG. 14 is a sectional view showing a first step of the third embodiment;
FIG. 15 is a sectional view showing a second step of the third embodiment;
FIG. 16 is a sectional view showing a third step of the third embodiment;
FIG. 17 is a sectional view showing a fourth step of the third embodiment;
FIG. 18 is a sectional view showing a fundamental arrangement of the cavity expanding and contracting foam injection molding method according to the present invention as a fourth embodiment;
FIG. 19 is a sectional view showing a first step of the fourth embodiment;
FIG. 20 is a sectional view showing a second step of the fourth embodiment;
FIG. 21 is a sectional view showing a third step of the fourth embodiment; and
FIG. 22 is a sectional view showing a fourth step of the fourth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
As shown in FIG. 3, an injection mold is used for foaming process. The injection mold is basically composed of two elements, that is, a mold element 1 and a mold element 2. The mold elements 1 and 2 are movable relative to each other in the directions shown by the arrow D. For the convenience of describing the embodiment, the mold element 1 will be referred to as a mold element on the stationary side, and the mold element 2 as a movable mold element.
The mold element 2 has a flat surface 4 formed on one side thereof. The mold element 1 has a partial rectangular parallelepiped surface 5 which defines a rectangular parallelepiped surface in cooperation with the flat surface 4. The mold elements 1 and 2 are slidable relative to each other. In such a slidable engagement of the mold elements 1 and 2, the flat surface 4 and the partial rectangular parallelepiped surface 5 define a rectangular parallelepiped surface inside the mold elements 1 and 2 joined together. Thus, a cavity is formed as a molding cavity 8 by the two mold elements 1 and 2, which is surrounded by a closed interface defined by the partial rectangular parallelepiped surface 5 of the mold element 1 and the flat surface 4 of the mold element 2.
In the first embodiment, the two cavity forming surfaces 5 and 4 of the two mold elements 1 and 2 form the closed cavity 8 when the two mold elements 1 and 2 are joined together, and a portion of the cavity forming surface 5 which is in the vicinity of the line L of intersection of the two cavity forming surfaces 4 and 5 is formed from a surface parallel to the direction of movement of the two mold elements 1 and 2.
Next, the cavity expanding and contracting foam injection molding method will be explained. FIG. 3 shows a state where the initial cavity 8 has been formed. As shown in FIG. 4, a molding material is charged into the initial cavity 8.
As the molding material, various kinds of engineering plastics, e.g., thermoplastic resin materials, may be employed. Thermoplastic elastomers may also be used. The molding material is mixed with a known blowing agent which appropriately decomposes in a predetermined time under predetermined pressure and temperature conditions, for example, an azodicarbonamide or oxybissulfonyl hydrazide compound.
Subsequently to the above-described charging step, the mold element 2 is moved forward, as shown in FIG. 5. Consequently, the cavity that is surrounded by the closed interface defined by the partial rectangular parallelepiped surface 5 of the mold element 1 and the flat surface 4 of the mold element 2 continuously contracts in the state of being closed. FIG. 5 shows a minimum intermediate cavity forming state where the cavity has contracted to a minimum volume. Next, the mold element 2 is moved backward. FIG. 6 shows the most backward position that is reached when the mold element 2 moves backward beyond the initial position where the initial cavity 8 is formed as shown in FIG. 4. FIG. 6 shows a maximum intermediate cavity forming state where the cavity has expanded to a maximum volume.
Next, the mold element 2 is moved forward. FIG. 7 shows a final step where a final cavity 9 has been formed. The volume of the final cavity 9 is larger than the volume of the minimum intermediate cavity, shown in FIG. 5, but smaller than the maximum intermediate cavity, shown in FIG. 6.
In the contracting step shown in FIG. 5, the pressure in the cavity rises during the contraction, causing the foaming species of the resin material to be dispersed and diffused. The resin material having foaming species uniformly dispersed therein is allowed to foam by the increase in volume, producing voids therein. When the resin material having voids produced therein contracts again, the sizes of the voids become uniform. In such a foaming process, the void size and the void density can be controlled by changing the rate of contraction of the minimum intermediate cavity and the rate of expansion of the maximum intermediate cavity.
Since the cavity expands and contracts in an oscillatory manner during the contacting process, the diffusion of the foaming species and the voids is further promoted, and the void sizes and densities are made uniform even more effectively.
FIG. 7 shows a foaming process in which the molding material charged in the previous charging step is allowed to foam in the final cavity 9, which has been expanded by the cavity expanding step, to form a foamed molded part having the same shape as that of the final cavity 9. The rectangular parallelepiped molded part formed in the injection mold is removed by moving the mold elements 1 and 2 away from each other in the same way as in the conventional practice.
Second Embodiment
As shown in FIG. 8, the injection mold used in the second embodiment is basically composed of three elements, that is, a mold element 1, a mold element 2, and a mold element 3. The mold elements 1 and 2 are movable relative to each other in the direction D. For the convenience of describing the embodiment, the mold element 1 will be referred to as a mold element on the stationary side, and the mold element 2 as a movable mold element.
The mold element 2 has a half-rectangular parallelepiped surface 14 formed on one side thereof. The mold element 1 is formed with a half-rectangular parallelepiped surface 15 which defines a substantially rectangular parallelepiped interface in cooperation with the half-rectangular parallelepiped surface 14. The mold elements 1 and 2 are butted against each other. In this butt state, the two half-rectangular parallelepiped surfaces 14 and 15 define a substantially rectangular parallelepiped surface inside the mold elements 1 and 2 butted against each other. The substantially rectangular parallelepiped surface is a rectangular parallelepiped surface lacking a part thereof. In other words, the rectangular parallelepiped surface has an opening.
The opening is provided in the mold element 1. The mold element 3 is slidably provided in the mold element 1 so as to project from the opening. Thus, a cavity is formed as a molding cavity 8 by the three mold elements 1, 2 and 3, which is surrounded by a closed interface defined by the half-rectangular parallelepiped surface 15 of the mold element 1, the half-rectangular parallelepiped surface 14 of the mold element 2, the partial rectangular parallelepiped surface 16 of the mold element 3, which is the projecting end surface thereof, and the remaining surface 17 of the projecting portion of the mold element 3.
In the second embodiment, the two cavity forming surfaces 15 and 14 of the two mold elements 1 and 2 form the closed cavity 8 when the two mold elements 1 and 2 are joined together, and portions of the cavity forming surfaces 14 and 15 which are in the vicinity of the intersection line L are formed from surfaces parallel to the direction of movement of the two mold elements 1 and 2.
In the process of shifting the initial cavity 8 (at the injection step shown in FIG. 10) to the final cavity 9 (at the final foaming step shown in FIG. 12), the cavity volume is temporarily made smaller than the volume of the initial cavity 8 (see FIG. 10) and then larger than the volume of the final cavity 9 (see FIG. 11) in the same way as in the first embodiment. The second embodiment differs from the first embodiment in that such a cavity expanding and contracting operation is effected by the forward and backward movement of the mold element 3, which is movable relative to the mold elements 1 and 2.
In the above-described foaming process, the cavity that is formed by the two mold elements 1 and 2 is expanded, while being kept closed, by the movement of the third mold element 3, which is movable independently of the mold elements 1 and 2. Accordingly, the cavity expands and contracts without the need of movement of the two mold elements 1 and 2. The rectangular parallelepiped molded part formed in the injection mold is removed by moving the mold elements 1 and 2 away from each other in the same way as in the conventional practice.
Third Embodiment
As shown in FIG. 13, the injection mold used in the third embodiment is basically composed of three mold elements, that is, a mold element 1, a mold element 2, and a mold element 3, in the same way as in the second embodiment. The mold elements 1 and 2 are movable relative to each other in the direction D. For the convenience of describing the embodiment, the mold element 1 will be referred to as a mold element on the stationary side, and the mold element 2 as a movable mold element.
The mold element 2 has a half-cubic surface 24 formed on one side thereof. The mold element 1 is formed with a partial cubic surface 25 which defines a substantially cubic interface in cooperation with the half-cubic surface 24. The mold elements 1 and 2 are butted against each other. In this butt state, the half-cubic surface 24 and the partial cubic surface 25 define a substantially cubic surface inside the mold elements 1 and 2 butted against each other. The substantially cubic surface is a cubic surface lacking a part thereof. In other words, the cubic surface has an opening.
The opening is provided in the mold element 1. The mold element 3 is slidably provided in the mold element 1 so as to project from the opening. Thus, a cavity is formed as a molding cavity 8 by the three mold elements 1, 2 and 3, which is surrounded by a closed interface defined by the partial cubic surface 25 of the mold element 1, the half-cubic surface 24 of the mold element 2, the partial cubic surface 26 of the mold element 3, which is the projecting end surface thereof, and the remaining surface 27 of the projecting portion of the mold element 3.
In the third embodiment, the two cavity forming surfaces 25 and 24 of the two mold elements 1 and 2 form the closed cavity 8 when the two mold elements 1 and 2 are joined together, and portions of the cavity forming surfaces 24 and 25 which are in the vicinity of the intersection line L are formed from surfaces which are not parallel to the direction of movement of the two mold elements 1 and 2. Such non-parallel surfaces 24 and 25 are not parallel to the direction D of movement.
In the process of shifting the initial cavity 8 (at the injection step shown in FIG. 14) to the final cavity 9 (at the final foaming step shown in FIG. 17), the cavity volume is temporarily made smaller than the volume of the initial cavity 8 (see FIG. 15) and then larger than the volume of the final cavity 9 (see FIG. 16) in the same way as in the first and second embodiments. The third embodiment is different from the first embodiment but the same as the second embodiment in that such a cavity expanding and contracting operation is effected by the forward and backward movement of the mold element 3, which is movable relative to the mold elements 1 and 2.
In the above-described foaming process, the cavity that is formed by the two mold elements 1 and 2 is expanded, while being kept closed, by the movement of the third mold element 3, which is movable independently of the mold elements 1 and 2. Accordingly, the cavity expands and contracts without the need of movement of the two mold elements 1 and 2. The cubic molded part formed in the injection mold is removed by moving the mold elements 1 and 2 away from each other in the same way as in the conventional practice.
Fourth Embodiment
FIG. 18 shows a fourth embodiment of the present invention. In this embodiment, a conventional injection molding machine is used for foaming process. The injection molding machine has a stationary platen 41, a movable platen 42, and a plurality of guide rods 43 for guiding the movement of the movable platen 42. The movable platen 42 is disposed to face the stationary platen 41 and driven by a hydraulic cylinder (not shown) to move forward and backward relative to the stationary platen 41.
The injection mold is basically composed of three elements, that is, a mold element 1, a mold element 2, and a mold element 3. The mold element 1 is attached to the movable platen 42. The mold element 2 is attached to the stationary platen 41. The mold elements 1 and 2 are movable relative to each other. For the convenience of describing the embodiment, the mold element 1 will be referred to as a mold element on the movable side, and the mold element 2 as a stationary mold element.
The mold element 1 is provided with a pneumatic cylinder 44. The top of a piston rod 45 of the pneumatic cylinder 44 is attached to the mold element 3. The mold element 3 is slidably guided in the mold element 1. The mold element 2 is provided with a gate 46. The cavity 8 is filled with a molding material containing a blowing agent from an injection nozzle of an injection pipe 47 through the gate 46.
The mold element 2 has a hemispherical surface 34 formed on one side thereof. The mold element 1 is formed with a hemispherical surface 35 which forms a substantially spherical surface in cooperation with the hemispherical surface 34. The mold elements 1 and 2 are butted against each other. In this butt state, the hemispherical surface 34 and the hemispherical surface 35 define a substantially spherical surface inside the mold elements 1 and 2 butted against each other. The substantially spherical interface is a spherical surface lacking a part thereof. In other words, the spherical surface has an opening.
The opening is provided in the mold element 1. The mold element 3 is slidably provided in the mold element 1 so as to project from the opening. Thus, a cavity is formed as a molding cavity 8 by the three mold elements 1, 2 and 3, which is surrounded by a closed interface defined by the hemispherical surface 35 of the mold element 1, the hemispherical surface 34 of the mold element 2, the partial spherical surface 36 of the mold element 3, which is the projecting end surface thereof, and the remaining surface 37 of the projecting portion of the mold element 3.
In the fourth embodiment, the two cavity forming surfaces 35 and 34 of the two mold elements 1 and 2 form the closed cavity 8 when the two mold elements 1 and 2 are joined together, and portions of the cavity forming surfaces 34 and 35 which are in the vicinity of the intersection line L are formed from surfaces which are not parallel to the direction of movement of the two mold elements 1 and 2. Such non-parallel surfaces, that is, the hemispherical surfaces 34 and 35, are not parallel to each other and not parallel to the direction D of movement of the two mold elements 1 and 2.
In the process of shifting the initial cavity 8 (at the injection step shown in FIG. 19) to the final cavity 9 (at the final foaming step shown in FIG. 22), the cavity volume is temporarily made smaller than the volume of the initial cavity 8 (see FIG. 20) and then larger than the volume of the final cavity 9 (see FIG. 21) in the same way as in the first, second and third embodiments. The fourth embodiment is different from the first embodiment but the same as the second and third embodiments in that such a cavity expanding and contracting operation is effected by the forward and backward movement of the mold element 3, which is movable relative to the mold elements 1 and 2.
In the above-described foaming process, the cavity that is formed by the two mold elements 1 and 2 is expanded, while being kept closed, by the movement of the third mold element 3, which is movable independently of the mold elements 1 and 2. Accordingly, the cavity expands and contracts without the need of movement of the two mold elements 1 and 2. The spherical molded part formed in the injection mold is removed by moving the mold elements 1 and 2 away from each other in the same way as in the conventional practice.
In the foregoing embodiments, the present invention has been described by way of an example in which a cavity forming surface in the vicinity of the intersection line L is a flat surface, a spherical surface, a torus surface, or a conical surface. However, molded parts generally have a more complicated three-dimensional interface. The present invention may be applied to the process of foaming three-dimensional objects having various interfacial configurations, e.g., a wheel, a damper of an air conditioner, a casing of a portable telephone, an armrest of a chair, etc.
In the foregoing embodiments, no explanation has been given of an intermediate process at the step of contracting the initial cavity 8 to the minimum intermediate cavity and at the step of contracting the maximum intermediate cavity to the final cavity 9. In such contracting steps, expansion and contraction may be repeated a plurality of times in an oscillatory manner. That is, it is possible to add an expansion and contraction step which is slowly carried out several times at a frequency of 2 to 5 times per second. Alternatively, the cavity may be contracted as a whole while being oscillated at a higher frequency.
For example, the contraction and expansion of the cavity volume may be carried out in the following sequence: the initial cavity→an intermediate cavity having a smaller volume than that of the initial cavity→an intermediate cavity having a larger volume than that of the final cavity→the final cavity. The sequence may also be such that: the initial cavity→an intermediate cavity having a larger volume than that of the initial cavity→an intermediate cavity having a smaller volume than that of the final cavity→the final cavity. Such intermediate steps may be repeated several times. By changing the intermediate cavity shifting process, it is possible to change the physical properties of the foamed molded part under control. During the above-described contraction and expansion step, the mold element that is moved may be finely vibrated.
Although the present invention has been described through specific terms, it should be noted here that the described embodiments are not necessarily exclusive and that various changes and modifications may be imparted thereto without departing from the scope of the invention which is limited solely by the appended claims.
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A foam injection molding method which makes it possible to control physical properties of high-expansion ratio molded parts with a high degree of freedom of interfacial configuration. With a molding material charged in a closed initial cavity (8) formed by three mold elements (1, 2 and 3), an intermediate cavity having a smaller volumetric capacity than that of the initial cavity (8) and an intermediate cavity having a larger volumetric capacity than that of a final cavity (9) are formed by moving at least one mold element (3) relative to the other two mold elements (1 and 2) without moving these mold elements (1 and 2) while keeping the cavity closed, which is formed by the three mold elements (1, 2 and 3).
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FOREIGN APPLICATION PRIORITY DATA
[0001] This application claims benefit of priority of Foreign Patent Application No. GB 09162992.3, filed in the United Kingdom on Jun. 17, 2009, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and computer program for processing affinity sets of related messages in a messaging and queuing system.
[0004] 2. Description of the Related Art
[0005] In recent years, the ability of application programs to communicate with each other or with system provided services in a computer system or network without having to become involved in the complexities of particular operating systems or communication protocols has been much enhanced by the development of Message Oriented Middleware (MOM). This is software running on top of a computer operating system which provides a common programming interface by means of which applications can communicate with other applications without specific knowledge of the different operating systems and/or protocols which may be used by those applications.
[0006] One example of Message Oriented Middleware (MOM) is the IBM WebSphere MQ product family. The most recent version, WebSphere MQ for z/OS Version 7.0 (“IBM”, “WebSphere” and “z/OS” are trademarks of International Business Machines Corporation), is described in an Information Center on the IBM Corporation website.
[0007] WebSphere MQ and other MOM products employ message queuing which allows programs to send and receive application specific data to each other without having a private, dedicated logical connection established between them. Instead, the applications communicate using messages containing a message descriptor and the application specific data. The messages are held on queues by a queue manager. The queue manager is effectively the runtime component of the MOM product and may also be referred to as a messaging server.
[0008] These queues may be accessed directly by applications on the same system using the same queue manager or their contents may be transmitted over a network or multi node system and placed on respective associated queues accessible to a receiving application via its respective local queue manager. In order to transmit messages to remote applications, the originating queue manager must first establish a communication channel to the remote queue manager. Both transmission and accessing of queued messages take place asynchronously.
[0009] Applications communicate with their associated queue managers via a standard application programming interface (API), known as the Message Queuing Interface (MQI) in the case of WebSphere MQ. Specific MQI commands cause the queue manager to store (MQPUT) messages on named destination queues, either directly, if local, or by transmitting them to the appropriate queue manager at a node elsewhere in the system and also to retrieve (MQGET) stored messages from such queues. A queue can be both a source of messages and a destination for messages.
[0010] Before an application program can put or get messages from a queue, it must first connect to the queue manager hosting the queue by means of an MQCONN call. The queue manager responds by returning a connection handle, sometimes referred to as Hconn, which is a unique identifier by which the program knows the queue manager. The program can then open the queue by supplying the connection handle as a parameter of an MQOPEN call, which establishes access to an object such as a queue. The output from the MQOPEN call includes an object handle, Hobj, which is an identifier by which the program knows the queue (or any other object) and is used as an input parameter for any subsequent MQI calls to the same queue. When an application has finished putting or getting messages from a queue, it normally closes the queue by means of an MQCLOSE call, specifying the appropriate object handle.
[0011] All MQI calls also require the selection of a number of other options or parameters, depending on the precise purpose and context of the operation to be carried out.
[0012] In large or heavily used messaging and queuing systems, problems of system administration, availability and workload balancing have been tackled by the use of clusters. Clusters are networks of queue managers that are logically associated. Communication between queue managers in a cluster is much simpler than between unrelated queue managers. Repository queue managers, to which all queue managers have access, have full knowledge of all queue managers in the cluster. Cluster queues are just queues hosted by a cluster queue manager and may be advertised to other queue managers within the cluster to simplify communication.
[0013] One aspect of clusters which is important in terms of workload balancing and availability is that more than one queue manager in the cluster can host an instance of the same queue. Because of this, the workload can be distributed between these queue managers, thereby increasing availability. Any one of the queue managers that hosts an instance of a particular queue can handle messages destined for that queue. This means that applications need not explicitly name the queue manager when sending messages. A workload management algorithm determines which queue manager should handle the message.
[0014] However, if, in order to benefit from workload management, a messaging and queuing network is set up to have multiple definitions (instances) of the same queue, it is always necessary to consider whether the applications using the system may have message affinities, that is, they exchange related messages which need to be processed on the same instance of a queue.
[0015] Because, with this type of cluster, a message can be routed to any queue manager that hosts a copy of the correct queue, the logic of applications with message affinities can be affected. Suppose for example, two applications rely on a series of messages flowing between them in the form of questions and answers. It might be important that all the questions are sent to the same queue manager and that all the answers are sent back to the other queue manager. In this situation, it is important that the workload management routine does not send the messages to any queue manager that just happens to host a copy of the correct queue. Similarly, some applications might require messages to be processed in sequence, for example a file transfer application or database replication application that sends batches of messages that must be retrieved in sequence.
[0016] In general, therefore, it is desirable to remove message affinities from applications as far as possible before starting to use clusters. Removing message affinities improves the performance of applications. For example, if an application that has message affinities sends a batch of messages to a queue manager and the queue manager fails after receiving only part of the batch, the sending queue manager must wait for it to recover before it can send any more messages, thereby degrading performance.
[0017] Removing messages affinities also improves the scalability of applications. A batch of messages with affinities can lock resources at the destination queue manager while waiting for subsequent messages. These resources may remain locked for long periods of time, preventing other applications from doing their work.
[0018] If message affinities can be removed so that it is not necessary to force all messages to be written to the same destination, an option MQOO_BIND_NOT_FIXED is specified on the MQOPEN call. This defers selection of a destination until MQPUT time, that is, on a message-by-message basis. Selection may then be made as determined by the cluster workload management algorithm.
[0019] However, removing message affinities in a clustered system is not always possible. The main problem to which the current invention relates is the limitation that message affinities prevent the cluster workload management routines from making the best choice of queue manager.
[0020] In such cases, where it is not appropriate to modify applications to remove message affinities, a number of partial solutions to the problem have been proposed. One solution is to specify the remote-queue name and the queue manager name on each MQOPEN call. In this case, all messages put to the queue using that object handle go to the same queue manager, which might be the local queue manager. This makes the application responsible for choosing queue managers in the cluster, something that the cluster software itself should be managing.
[0021] A variation on this solution is to allow the queue manager that receives the first message in a batch to return its name in response. The queue manager at the sending end can then extract this queue manager name and specify it on all subsequent messages. The advantage of this method over the previous one is that some workload balancing is carried out to deliver the first message.
[0022] The disadvantage of this method is that the first queue manager must wait for a response to its first message before sending subsequent messages. As with the previous method, if there is more than one route to the queue manager, the sequence of the messages might not be preserved.
[0023] The currently preferred solution is to force all messages to be put to the same destination within the cluster, by specifying an option MQOO_BIND_ON_OPEN on the MQOPEN call. By specifying MQOO_BIND_ON_OPEN, all messages that are sent to this queue are forced to be sent to the same queue manager and thus to the same instance of the queue. MQOO_BIND_ON_OPEN binds all messages to the same queue manager and also to the same route. For example, if there is an IP route and a NetBIOS route to the same destination, one of these will be selected when the queue is opened and this selection will be honored for all messages put to the same queue using the object handle obtained.
[0024] By specifying MQOO_BIND_ON_OPEN all messages are forced to be routed to the same destination. Therefore applications with message affinities are not disrupted. If the destination is not available, the messages remain on the transmission queue until it becomes available again.
[0025] All of the above known solutions have the limitation, however, that each queue hosting a set of affinity messages must be separately opened with MQOPEN, restricted according to the above suggested solutions and then closed with an MQCLOSE call before workload management can be resumed for other message processing tasks of the application which do not have affinities or before different affinity sets can be processed. Opening and closing queues in this way consumes both time and resources.
SUMMARY OF THE INVENTION
[0026] Accordingly, the present invention provides a method of processing messages, including affinity sets of related messages, in a messaging and queuing system of the type capable of supporting a cluster of logically associated messaging servers for controlling and hosting queues of messages, including multiple instances of the same queue on respective messaging servers, the method comprising: in response to an application program command to a first messaging server, opening a queue having multiple instances on respective messaging servers of the cluster; in response to application program commands to said first messaging server to put messages on said queue, distributing messages among the multiple instances of the queue on their respective messaging servers so as to balance the workload between the servers according to predetermined rules; where the message being put is the first message of an affinity set, obtaining and storing access information for the particular queue instance to which said first message is put; and in response to an application program command to said first messaging server to put a further message to the open queue, if said message is part of the affinity set, using the access information in order to send the further message to the particular queue instance and, if said further message is not part of the affinity set, putting it to an instance of the queue as determined by said predetermined rules.
[0027] Thus by using workload distribution information obtained in the course of the first put operation of an affinity set of messages, messages of the set can be routed to the same queue manager and queue instance and subsequent unrelated sets or messages can be routed to other queues for workload management or other reasons without the first selected queue having to be closed. This gives greater flexibility and efficiency to the system in handling a mixture of affinity sets and other messages.
[0028] The application is able to pass workload distribution information between messages in an affinity set to ensure that a set of logically related messages are processed by the same server. This makes it simple to design conversational applications with message affinities which can still cope with workload distribution of sets of messages which are not related to each other.
[0029] Preferably, workload balancing is specified by means of an option in the application program open command which causes selection of the queue instance to be deferred until a command to put messages on the queue is received.
[0030] The access information may be an object handle for the queue instance selected by said workload balancing step which was generated as a result of the opening of said queue instance by said first messaging server. In such a case, each further message of an affinity set is put to the same queue instance as its predecessor by reference back to the access information associated with the predecessor message.
[0031] Alternatively, the access information may be derived from a message attribute of said first message of the affinity set, created when a particular queue instance is selected for said first message.
[0032] According to a further aspect, the invention also comprises a computer program for carrying out the above method steps.
[0033] According to a yet further aspect, the invention also comprises a messaging and queuing network for processing messages, including affinity sets of related messages, comprising a cluster of logically associated messaging servers for controlling and hosting queues of messages including multiple instances of the same queue on respective messaging servers, the network comprising: means responsive to an application program command to a first messaging server to open a queue having multiple instances on respective messaging servers of the cluster; means responsive to application program commands to said first messaging server to put messages on the queue; means for distributing messages among the multiple instances of said queue on their respective messaging servers so as to balance the workload between the servers according to predetermined rules; means for obtaining and storing access information for the particular queue instance to which the first message of an affinity set is put; and means responsive to an application program command to said first messaging server to put a further message to the open queue, effective, if said message is part of the affinity set, to use the access information in order to send the further message to the particular queue instance and, if said further message is not part of the affinity set, to put it to an instance of the queue as determined by said predetermined rules.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0035] FIG. 1 is a schematic diagram of a queue manager cluster in a messaging and queuing system in which the present invention may be employed;
[0036] FIG. 2 represents a mixed string of messages including two affinity sets which may be processed in the cluster of FIG. 1 according to one example of the present invention;
[0037] FIG. 3 is a sequence diagram showing how the string of messages of FIG. 2 is processed according to this example of the present invention;
[0038] FIG. 4 is a flow diagram further illustrating the steps of processing the string of messages of FIG. 2 ;
[0039] FIG. 5 represents a further mixed string of messages including two affinity sets whose messages are intermingled which may processed in the cluster of FIG. 1 according to a second example of the present invention;
[0040] FIG. 6 is a sequence diagram showing how the string of FIG. 5 is processed according to the second example of the present invention; and
[0041] FIG. 7 is a flow diagram illustrating the process steps of the second example of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] FIG. 1 illustrates a typical cluster 10 of queue managers, such as IBM's WebSphere MQ Version 7, in a messaging and queuing network. Four queue managers QM 1 , QM 2 , QM 3 and QM 4 are shown hosting a number of queues Q 1 , Q 2 , Q 3 , Q 4 and Q 5 . Although queues Q 1 , Q 2 , Q 4 and Q 5 are unique, two instances, labeled 11 and 12 , of Q 3 are shown on queue managers QM 2 and QM 4 respectively. Such a cluster, including the multiple queue instances, is defined by a systems administrator when the cluster is first set up.
[0043] If an application on QM 2 or QM 4 puts a message to Q 3 , the local instance of Q 3 , 11 or 12 respectively, is used. However, when an application on QM 1 puts a message on QM 3 , since it does not have a local instance of the queue, it does not necessarily know which instance, 11 or 12 , of QM 3 will process its message.
[0044] If the MQOPEN call, opening Q 3 , specifies the MQOO_BIND_NOT_FIXED option, the instance, 11 or 12 , which is selected is determined by the workload management algorithm for the cluster. Subsequent messages put to the queue may thus go to either instance depending on the loading and algorithm.
[0045] If the MQOPEN call specifies the MQOO_BIND_ON_OPEN option, all messages put by QM 1 to Q 3 will go to the same instance of Q 3 until the queue is closed by an MQCLOSE call. Which of the two instances is chosen depends on how the first message to the queue was routed.
[0046] Thus, in the workload-balancing cluster of FIG. 1 , the preferred situation, where there are multiple instances of a queue such as Q 3 , is that messages from QM 1 having no affinity with each other are distributed between queue managers QM 2 and QM 4 based on workload. This is achieved by specifying the MQOO_BIND_NOT_FIXED option when an application opens a queue such as Q 3 .
[0047] However, if messages do have an affinity with each other, they must be processed together in the same queue manager QM 2 or QM 4 . Conventionally, this is achieved by the application specifying the MQOO_BIND_ON_OPEN option when it opens Q 3 and using the object handle returned as output from the MQOPEN call to ensure that all messages subsequently put to the queue are sent to the same queue instance. However, this entails opening the queue separately for each affinity set of messages and closing it once all of the set of messages has been sent. Where there are multiple affinity sets, this can result in performance degradation.
[0048] Two examples of strings of messages, including affinity sets, will now be considered, in order to illustrate the operation of the present invention. It is assumed that the strings are sent by queue manager QM 1 to queue Q 3 on either QM 2 or QM 4 . The first example is illustrated in FIG. 2 and comprises a first affinity set of messages S 1 , S 2 and S 3 , two unconnected messages M and N and a further affinity set of messages T 1 and T 2 . It is necessary that the set S 1 -S 3 should be sent to the same instance of Q 3 and that the set T 1 , T 2 should also be sent to the same instance of Q 3 (though not necessarily the same one as set S 1 -S 3 ). It is unimportant to which instance of Q 3 the separate individual messages M and N are sent. A possible alternative scenario, which could be represented by FIG. 2 , would be that either of the sets represents a conversation between an application program on QM 1 and a target program on either QM 2 or QM 4 . Either way, it is necessary that each complete affinity sets end up on the same target queue instance.
[0049] FIG. 3 is a sequence diagram illustrating one way of processing the messages of FIG. 2 without the need to close and reopen the queue Q 3 . In FIG. 3 , queue managers QM 1 , QM 2 and QM 4 are represented by vertical bars. QM 2 and QM 4 host the target queue Q 3 , as previously indicated. An application program, hosted on QM 1 , is also represented by a vertical bar to the left of QM 1 .
[0050] The first step shown in line 30 is for the application program to open Q 3 by making an MQOPEN call on QM 1 , specifying the BIND_NOT_FIXED option. No local instance of Q 3 exists on QM 1 although two instances 11 and 12 of the target queue Q 3 exist on respective queue managers QM 2 and QM 4 . Consequently, specifying the BIND_NOT_FIXED option to QM 1 means that an MQPUT call on line 32 to QM 1 to put the first message S 1 of the affinity set S to queue Q 3 invokes the workload management algorithm, also represented by a vertical bar. This algorithm distributes the message S 1 to QM 2 , say, and to the instance of Q 3 hosted on QM 2 .
[0051] The selection made by the workload algorithm causes QM 1 (line 33 ) to associate the instance on QM 2 with the object handle. This could be done automatically but in this example is the result of an additional option on the MQPUT call: “SAVE_BIND_INFO”. This causes QM 1 to remember the distribution information pointing to the just selected instance of Q 3 . Since the originating application program knows that the next message S 2 is part of an affinity set with S 1 , when it puts S 2 to Q 3 (line 34 ) it includes a special option on the MQPUT call: “BIND_AS_PREVIOUS”. This ensures that, by referring to the associated distribution information, message S 2 is put to the same Q 3 instance as S 1 , namely the one on QM 2 . Once again, the queue manager remembers the selected instance of Q 3 (line 35 ) and associates it (line 35 ) with the relevant object handle.
[0052] After this, message S 3 is put to Q 3 (line 36 ) in the same way as S 2 , namely, using the BIND_AS_PREVIOUS option. Further distribution information is no longer needed since the application knows the next message M is not part of the affinity set. The arrowed curved lines in FIG. 2 represent the BIND_AS_PREVIOUS associations between affinity set messages and their immediately preceding messages of the set.
[0053] In fact, neither of the next two messages M and N from QM 1 is part of an affinity set and so may be put to either instance of Q 3 by the workload management algorithm. By way of example, message M is shown on line 37 as being put to the instance of Q 3 on QM 4 whereas message N is shown on line 38 as being put to the instance of Q 3 on QM 2 .
[0054] Next, the further affinity set T is processed and message T 1 is put (line 39 ) to whichever queue manager hosting Q 3 is selected by the workload management algorithm. For the purposes of this example, the selected queue manager is assumed to be QM 4 . As was the case with set S, the selection information for message T 1 is saved (line 40 ) and used by QM 1 to associate the object handle for the Q 3 instance on QM 4 with the set T. When message T 2 is put to Q 3 , on line 39 , BIND_AS_PREVIOUS is again specified so that it also goes to the Q 3 instance on QM 4 .
[0055] Thus, although normal workload management for messages put to Q 3 was initially selected by specifying the BIND_NOT_FIXED option, it is overridden for sets S and T to make sure that they arrive on respective single instances of Q 3 . Assuming the application has finished with Q 3 for the time being, the two instances of Q 3 on QM 2 and QM 4 may now be effectively closed (line 42 ) by QM 1 disconnecting from them.
[0056] FIG. 4 is a flow diagram further illustrating the process steps of the invention, as used in the example of FIGS. 2 and 3 . In step 49 , the target queue Q 3 , which has multiple instances on QM 2 and QM 4 , is opened, specifying BIND_NOT_FIXED. Assuming, there are messages to be processed and this is not the end of the message string, as determined by step 50 , the first message is supplied for putting to the target queue in step 52 .
[0057] The application program knows whether this message is part of an affinity set. If it is not, as indicated by decision box 53 , it is put to whichever instance of the target queue is selected by the workload management algorithm in step 54 . If it is part of an affinity set and is the first message of the set, as indicated in decision box 55 , the workload management algorithm is again used, in box 56 , to select the target queue instance and send the message to that instance. The distribution information is saved in step 59 in response to the SAVE_BIND_INFO having been specified. Control then returns to step 50 and awaits the next message, upon receipt of which appropriate ones of the above steps will be repeated.
[0058] If the next message is also part of the affinity set, other than the last, as determined in step 58 , it is sent to the queue instance identified by the saved distribution information, as a result of the BIND_AS_PREVIOUS option being specified on the PUT call. Again, the distribution information is saved in step 59 . When the last message of the affinity set is put, as indicated by the negative output from decision step 58 , it is not necessary to save further distribution information and control returns directly to step 50 . When the result of step 50 is that there are no more messages to send, the queue is closed in step 51 .
[0059] This invention thus offers the capability to route different affinity sets of messages to queues on different messaging servers without first having to close the queues between the different sets of messages or disable normal workload management.
[0060] The approach of FIGS. 3 and 4 is sufficient for many applications where each affinity set is an unbroken string of messages. However, it will not work in more complex situations where messages of different affinity sets may be interleaved with each other or mingled with ordinary messages. This is because the BIND_AS_PREVIOUS option causes a message to be routed to the same destination as the immediately preceding message, which, in the more complex example, may not be part of the same affinity set.
[0061] FIG. 5 shows an exemplary message string of this type. In this string, a first affinity set consisting of messages U 1 , U 2 , and U 3 is interleaved with an unrelated single message W and with a second affinity set consisting of messages V 1 and V 2 . It can be seen that routing messages to the queue instance of the preceding message would not result in all members of the same affinity set ending up on the same queue instance.
[0062] This can be overcome by associating workload distribution information with each particular set and using this, rather than the more general, BIND_AS_PREVIOUS option to determine where subsequent members of the set are sent. This distribution information is returned by the queue manager to the application when the message has been put. In WebSphere MQ, either a message descriptor or a message handle can be used to provide a mechanism for returning distribution information about a message to the application.
[0063] FIG. 6 is a sequence diagram illustrating this alternative way of processing messages, using the exemplary string of messages of FIG. 5 . Again, the application program, the three queue managers QM 1 , QM 2 and QM 4 and the Workload Algorithm are represented by vertical bars.
[0064] The first step, in line 60 , is for the application program to issue an MQOPEN call to open Q 3 . No local instance of Q 3 exists on QM 1 but two instances, 11 and 12 of FIG. 1 of Q 3 exist on queue managers QM 2 and QM 4 . As with FIG. 3 , the MQOPEN call specifies BIND NOT_FIXED. This effectively activates the workload management algorithm for QM 1 . Then, an MQPUT call is issued to put the first message U 1 of an affinity set, U, to queue Q 3 . The workload management algorithm decides to send this message to the instance of Q 3 on queue manager QM 2 . These actions are represented by line 62 .
[0065] QM 1 remembers which version of Q 3 was chosen (line 63 ) and returns this choice in the message handle supplied to the application, as output from the MQPUT call. The message handle is associated with and stored for use with further members of set U.
[0066] However, the next message to be put, V 1 , is from a different affinity set so the previously stored message handle is not used and, instead, the workload algorithm is used to determine the queue instance of Q 3 to be used and chooses that on QM 4 , as indicated by line 64 . The selection of QM 4 (line 65 ) is remembered by QM 1 and returned to the application in a further message handle for future reference in connection with set V.
[0067] Next a single message W, which is not a member of either affinity set, is put to the instance of Q 3 on QM 2 , as determined by the workload management algorithm (line 66 ). In this case, a message handle may be returned in the normal course of events but is not needed for distribution purposes and so is not illustrated.
[0068] After this, the remaining members U 2 and U 3 of affinity set U are put to the instance of Q 3 indicated by the stored message handle for set U, as shown in lines 67 and 68 . Finally, on line 69 , the final message V 2 of set V, is put to the instance of Q 3 on QM 4 , as indicated by the stored message handle for set V. Reference back to the first message handle of each affinity set is also represented in FIG. 5 by arrowed lines.
[0069] Assuming all necessary messages have been put for the time being, the application program on QM 1 may then issue an MQCLOSE call on line 61 to close Q 3 . The instances of Q 3 on queue managers QM 2 and QM 4 do not necessarily disappear but are effectively disconnected by QM 1 .
[0070] FIG. 7 is a flow diagram illustrating the process steps of the invention, as used in the example of FIGS. 5 and 6 . The initial steps are identical to those of FIG. 4 . Thus, in step 70 , the target queue Q 3 , which has multiple instances on QM 2 and QM 4 , is opened, specifying BIND_NOT_FIXED. Assuming, there are messages to be processed and this is not the end of the message string, as determined by step 71 , the first message is supplied for putting to the target queue in step 72 .
[0071] The application program knows whether this message is part of an affinity set. If it is not, as indicated by decision box 73 , it is put to whichever instance of the target queue is selected by the workload management algorithm in step 74 . If it is part of an affinity set and is the first message of the set, as indicated in decision box 75 , the workload management algorithm is again used, in box 76 , to select the target queue instance and send the message to that instance. Control then returns to step 71 and awaits the next message, upon receipt of which appropriate ones of the above steps will be repeated.
[0072] When the workload distribution information for the first message of a set has been made, in step 76 , the selection is incorporated in the message handle and this is returned to and stored by the application in step 77 . In step 78 , this information is then used to route subsequent messages of the affinity set to the same instance of the target queue, after which, control returns to step 71 , to await the next message. When the application decides it has no more messages to send, as detected in step 71 , it closes the target queue in step 79 .
[0073] So, to summarize, for the “BIND_AS_PREVIOUS” method of FIGS. 4 and 5 , no workload distribution information need be returned to the application. The queue manager can remember it on behalf of the application and use this information when it receives the next “BIND_AS_PREVIOUS” request.
[0074] The more flexible message handle technique of FIGS. 6 and 7 requires the application to be able to refer to a particular set of workload distribution information. Using a message handle returned by MQPUT, the message handle can contain the information which can subsequently be used on the call to put another message in the same affinity set.
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In a messaging and queuing system that supports a cluster of logically associated messaging servers for controlling queues of messages, messages are processed. In response to an application program command to a first messaging server, a queue is opened, the queue having multiple instances on further messaging servers of the cluster. Responding to first messaging server putting messages on the queue, messages are distributed among the multiple instances of the queue on their respective messaging servers so as to balance. For the first message of an affinity set, access information for the particular queue instance to which it is put is obtained and stored. The access information may be used in order to send the further message to the particular queue instance and, if said further message is not part of the affinity set, it is put to an instance of the queue as determined by said predetermined rules.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to air conditioning systems and, more particularly to an evaporator coil having a single row of tubes.
[0002] An evaporator coil is ordinarily made up of a plurality of sections, with each section having two or more rows of tubes. The tubes are commonly interconnected at their ends by return bends such that one or more circuits are formed with a plurality of interconnected tubes such that, with the introduction of refrigerant into a first tube, the refrigerant flows successively through the tubes until it reaches a last tube, after which the refrigerant flow then passes out of the coil and is made to flow to the compressor.
[0003] An air conditioning system is so designed that the refrigerant passing into successive tubes gets progressively evaporated, and when it reaches the last tube, it is in a superheated vapor condition. The purpose of this is to protect the compressor by preventing any liquid refrigerant from passing to the compressor.
[0004] It is recognized that superheat tubes can potentially be above the air dew point temperature. Accordingly, humid air passing over the superheat tube is not dehumidified as is the air passing over the other non superheated tubes. If nondehumidified air is allowed to pass through the heat exchanger, it may cause a fogging effect downstream thereof. That is, as the high humidity air mixes with cold air downstream, fog can be generated, or condensation can form on cold surfaces. The result may be that fog and/or water is then blown into the conditioned space. With a coil of two or more rows, this problem is overcome by the fact that the air passing over the superheat tube has passed or will pass over a nonsuperheated tube from another row. Thus the air passing over the superheated tube is dehumidified by a nonsuperheated tube, and the fogging problem is averted.
[0005] For purposes of reducing cost and weight, it would be desirable to replace a multi-row, low fin density coil with a single row, high fin density coil. However, since there is no adjacent unsuperheated tube to dehumidify the air passing over the superheated tube, the problem of fog generation is present.
[0006] It is therefore an object of the present invention to provide an improved single row coil.
[0007] Another object of the present invention is the provision for overcoming the problem of fogging in a single row coil.
[0008] Yet another object of the present invention is the provision for reducing the flow of non-dehumidified air from a single row coil.
[0009] Still another object of the present invention is the provision for a single row coil which is economical to manufacture and effective and efficient in use.
[0010] These objects and other features and advantages become readily apparent upon reference to the following descriptions when taken in conjunction with the appended drawings.
SUMMARY OF THE INVENTION
[0011] Briefly, in accordance with one aspect of the invention, provision is made in a single row coil for the air flow to be diverted in such a way that the air being cooled and passing over a superheat tube in the circuit is also made to pass over a nonsuperheat tube such that the air is dehumidified prior to its passing downstream of the coil.
[0012] By yet another aspect of the invention, at least one baffle is placed near the heat exchanger superheat tube such that the incoming air flow is diverted to obtain the desired dehumidifying effect.
[0013] By yet another aspect of the invention, a pair of baffles are provided in the vicinity of the superheat tube, with one on each side of the tube row, and with the two being staggered such that the desired air flow diversion is obtained.
[0014] By still another object of the present invention, the diversion of air can be such that the air passes first over the superheat tube and then over a nonsuperheat tube or first over a nonsuperheat tube and then over a superheat tube.
[0015] In the drawings as hereinafter described, a preferred embodiment is depicted; however, various others modifications and alternate constructions can be made thereto without departing from the true sprit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a schematic illustration of a conventional two-row coil system with the pattern of air flow shown.
[0017] [0017]FIG. 2 shows a schematic illustration of a one-row coil system.
[0018] [0018]FIG. 3 is a schematic illustration of a one-row coil system with the present invention incorporated therein.
[0019] [0019]FIG. 4 is a schematic illustration of an alternative form of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring now to FIG. 1, a two-row coil system is shown with three sections 11 , 12 and 13 , with each section having two rows of tubes as shown. Within each section, refrigerant is caused to flow between successive tubes, with the refrigerant quality progressively increasing (i.e. evaporating) in each tube. That is, as the fan 14 draws air through the sections as indicated by the arrows, the air is cooled by the cooler refrigerant in the tubes, and conversely the refrigerant is heated by the air. The system is designed such that the temperature of the two-phase refrigerant in the tubes is below the air dew point temperature in most of the tubes, but when it reaches the last tube in the section, the temperature of the refrigerant vapor is typically above the air dew point temperature. These last tubes are referred to as superheat tubes and are indicated by the number 16 , 17 and 18 in the respective sections 11 , 12 and 13 .
[0021] The purpose of the superheat tubes is to ensure that the refrigerant passing to the compressor is in a superheated stage and not in a liquid or two-phase stage since the compressor may be damaged by liquid refrigerant. However, it is recognized that the cooling ability of the superheat tube is different from the nonsuperheat tubes in the coil. That is, when the warm humid air enters the coil, the nonsuperheat tubes have sufficient cooling capacity to also dehumidify the air passing through, whereas the superheat tubes, typically being above the air dew point temperature, are not capable of dehumidifying the air. Because of the two-row structure, this is not a problem since the air passing across the superheat tubes is previously passed over the nonsuperheat tubes where the air is dehumidified. The result is that all of the air passing downstream of the fan 14 is cold dry air.
[0022] Considering now a coil with sections 19 , 21 and 22 having a single row of tubes as shown in FIG. 2, it should be pointed out that there are only two circuits in the three sections, with one circuit starting in section 19 and ending in section 21 , and with the other circuit starting in section 21 and ending in section 22 . Here, the problem of having nondehumidified air can occur. That is, each of the nonsuperheat tubes 23 are sufficiently cool as to be capable of dehumidifying the air passing through the coil. But the superheat tubes 24 and 26 can, again, be above the air dew point temperature and therefore not capable of dehumidifying the air. Further, unlike in the two coil arrangement as described hereinabove, the air passing over the superheat tubes 24 and 26 does not pass over any of the nonsuperheat tubes 23 . As a result, the air passing over the superheat tubes 24 and 26 is humid air which, when mixed with cold air downstream, can cause the generation of fog or the formation of condensate on cold surfaces. This can, in turn, cause fog or water to be blown into the conditioned space. This problem is addressed by the inventive arrangement as shown in FIG. 3.
[0023] In order to dehumidify the air passing over the superheat tubes 24 and 26 the air flow is diverted by a pair of baffles 27 and 28 in section 21 and baffles 29 and 31 in section 22 . As will be seen, the baffle pairs are staggered in respect to their respective superheat tubes such that the air flow is redirected from the superheated tubes to an adjacent two phase tube to thereby further cool the air and thereby dehumidify it. This eliminates the previously described problem of fog and condensate formation caused by the mixing of cold, dry air with warmer humid air.
[0024] As an alternative to the above arrangement, wherein the air to be cooled flows first over the superheat tube 26 and then over the two phase tube, the baffles can be rearranged as shown at 32 and 33 of FIG. 4 wherein the air passes first over the two phase tube 34 and then over the superheat tube 26 .
[0025] While the present invention has been particularly shown and described with reference to a preferred and an alternative mode as illustrated in the drawings, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
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In a single row evaporator coil having a last tube receiving refrigerant in a superheated condition, at least one baffle is provided to divert the flow of air passing over the superheat tube such that it also passes over a nonsuperheat tube so that air can be dehumidified by the cooling effect of the nonsuperheat tube prior to the air being passed downstream.
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BACKGROUND OF THE INVENTION
Char forming or intumescent flame retardant compositions are well known in the painting, coating and plastics fields. These systems generally consist of three components: an acid generating component, a char forming component and a blowing agent. The theory and background of such intumescent flame retardant systems are widely reported in the literature; see, for example, The Chemistry and Uses of Flame Retardants, J. Lyons, (Wylie-Interscience, New York, N.Y., 1970) pages 256-280; "Intumescent Coating Systems, Their Development and Chemistry", H. L. Vandersall, J. Fire & Flammability, Volume 2, pages 97-140, (April, 1971).
Vandersall describes the commercial use of ammonium polyphosphate (APP) as an acid generator, dipentaerythritol (DPE) as a char former, and melamine (ME) as a blowing agent in a system for painting and coating applications. U.S. Pat. No. 3,810,862 to Mathis et al. describes using an APP/DPE/ME system in plastics. U.S. Pat. No. 4,198,493 to Marciandi describes an intumescent flame retardant system for use in paints and plastics in which the polyhydroxy component DPE is replaced by the polyhydroxy compound tris(2-hydroxyethyl) isocyanurate (THEIC).
U.S. Pat. No. 4,727,102 to Scarso discloses a flame retardant polymer composition which appears to be similar to U.S. Pat. No. 4,198,493 and describes one embodiment comprising a mixture of APP, melamine cyanurate (MC) and a hydroxyalkyl derivative of isocyanuric acid wherein the derivative of isocyanuric acid is in the form of a homopolymer. Additionally, U.S. Pat. No. 4,727,102 discloses (see column 2, lines 48-56) a polypropylene polymer containing a two-component flame-retardant additive system consisting of 65% polypropylene, 15% APP and 20% THEIC (based on weight percentages), wherein the polypropylene polymer with the flame-retardant system has a VO, UL94 rating (see explanation of UL94 test and rating method below) with poor mechanical and thermal characteristics. Flame retardant polymer compositions based upon halogenated organic compounds, phosphorous containing organic compounds, and halogenated organic compounds/antimony oxide mixtures are well known. These systems suffer from several disadvantages, however, that make their use undesirable. The addition of these types of flame-retardant additives to polymers reduces the physical properties of the polymers, such as tensile strength, impact strength, flexural strength and elongation. Additionally, because of environmental and safety factors, it is desirable to get away from systems employing halogenated components.
One of the factors complicating the search for suitable flame retardant additives is the different behavior and properties of the various materials to be rendered flame retardant. This includes the need for different loading levels of flame retardant additives depending on the type of polymer system being considered. For example, polyolefins may require loadings of 30-50 weight percent, polyamides may require loadings of 20-25 weight percent and thermoplastic polyesters may only require loadings of 12-20 weight percent. Depending on the polymer system used and the type and amount of flame retardant used, the physical and mechanical properties of the polymer system may be adversely impacted.
Another problem that has been investigated in this area is the problem of finding suitable drip retardants (also called drip suppressants). It is known that flaming polymer droplets increase the spread of fire and efforts have been made to produce flame retardant polymer compositions which do not exhibit this flame spreading tendency. Many of these attempts at finding drip suppressants have been based on halogenated or phosphorous-organic compound type flame retardant systems, perhaps because the intumescent type of flame retardant systems are generally more drip suppressing than those which are not intumescent.
H. L. Vandersall (at pages 129-130 of the reference discussed above) discloses that the quality of an intumescent foam generated by an intumescent flame retardant system can be improved by the incorporation of finely divided solids into the system. Such particles are believed to assist in the "nucleation" of the foam.
Other references describe improved flame retardant polymer compositions obtained by the use of additives such as fiber glass (see U.S. Pat. No. 4,490,504 to Mark), or polytetrafluoroethylene powder (see U.S. Pat. No. 4,344,878 to Dolce; U.S. Pat. No. 4,107,232 to Haaf, et al; and U.S. Pat. No. 3,671,487 to Abolins). These references describe polymer compositions containing halogen or phosphorous or similar types of materials.
Additionally, problems have been encountered in the processability of polymers to which flame retardants have been added. For example, in flame retardant polymers containing only APP and THEIC two particular processing problems are screw slippage and mold plate-out (also called mold deposit or bloom). THEIC melts at about 140 degrees C., but is incompatible with most polymer systems. Because of its low melt temperature it is believed that the THEIC acts as a plastizer in the polymer melt. The viscosity of THEIC in such a system is about 1 centipoise. The THEIC migrates to the outside of the melt surface while it is being processed in the extruder. Since the extruder relies on friction of the melt with the metal barrel, and the THEIC reduces the friction between the melt and the metal barrel to almost zero, screw slippage occurs. Also, the migration of THEIC to the surface of the polymer may cause a plate-out of the THEIC on injection molding surfaces. Over time this plate out effect will result in the cessation of molding so that the molds can be cleaned. Additionally, the molded parts themselves may have a sticky or tacky surface. One attempt at solving bloom problems in intumescent flame retardant systems containing APP is described in U.S. Pat. No. 3,936,416 to Brady.
There still remains a need, however, for improved flame retardants which can be added to thermoplastic polymer systems. It is, therefore, an object of this invention to provide improved flame retardants suitable for use in thermoplastic polymer systems, including homopolymers of polyolefins and copolymers, terpolymers, et cetera of one or more polyolefins. It is also an object of this invention to provide flame retardants and polymer systems containing such flame retardants which result in thermoplastics having improved processability, including the reduction of screw slippage, the reduction of mold plate-out, and the reduction of surface bloom problems. It is yet another object of this invention to provide flame retardants and polymer systems containing such flame retardants which result in thermoplastics having good mechanical properties. These and other objects of the invention will become apparent from the description of the invention.
SUMMARY OF THE INVENTION
This invention relates to improved flame retardants and thermoplastic polymer systems formed therewith. The improved flame retardant comprises a combination of an amine/melamine catalyst such as ammonium polyphosphate; a char-forming agent such as tris(2-hydroxyethyl) isocyanurate; and a selected silica in an amount from 0.5 percent to an amount equal to one-half the amount by weight of THEIC, wherein a) the total amount of APP and THEIC in the thermoplastic polymer is from about 20 percent to about 50 percent based on the weight of the total flame retarded polymer system; b) the weight of APP to THEIC is from about 2:1 to about 6:1; and c) the selected silica meets defined surface area, particle size and absorption criteria. Optionally, from 0.5 to about 5.0 percent by weight (based on the weight of the flame retardant thermoplastic resin system) of a pigment selected from the group consisting of SiO 2 , TiO 2 , SnO 2 , ZnO, Sb 2 O 3 , Fe 2 O 3 , ZnBO 3 and polytetrafluoroethylene (PTFE) or mixtures thereof may be added. The total amount of pigment and selected silica in the thermoplastic polymer composition is at least 0.5 percent by weight.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to improved flame retardants and thermoplastic polymer systems formed therewith. The thermoplastic polymers with which the polymer systems are formed are polyolefins, including polyethylene, polypropylene, ethyl vinyl acetate copolymer (EVA), polybutylene, and ethylene ethyl acrylate; such polymers include homopolymers, and blends of two or more polyolefins, and copolymers, terpolymers, et cetera of such polyolefins. Specific examples of such polymers include A) polyethylene, polypropylene, and polybutylene, including homopolymers and copolymers thereof and various types of such polymers (for example, high density, low density); B) a copolymer, terpolymer, et cetera of two or more polymers such as, for example, i) a copolymer made with ethyl vinyl acetate and ethylene, and ii) a crystalline copolymer made with ethylene and propylene; and C) a blend of two or more polymers, for example, polypropylene and polyethylene in any ratio.
The improved flame retardant comprises a combination of a catalyst such as an amine/melamine phosphate, for example and in particular ammonium polyphosphate; a charforming agent such as tris(2-hydroxyethyl) isocyanurate; and at least 0.5 percent of a selected silica characterized as having a surface area (as measured by the BET test described below) of at least 450 m 2 /gram; a particle size less than or equal to 4.5 microns; a tapped density (also called bulk density) of less than or equal to 80 grams/liter; and an absorption (as measured by a Dibutyl Phthalate test described below) of at least 330 percent or a Packing Fraction value (test described below) of at least 0.8.
The total amount of the APP/THEIC component in the polymer composition may be from about 20 percent to about 50 percent by weight based on the weight of the final polymer system containing the flame retardant. More particular values for the APP/THEIC component are from 20 percent to 40 percent by weight. The loading level of the APP/THEIC combination should desirably be selected to be at least about 25 percent to about 30 percent based on the weight of the final polymer system. It is believed that this level of loading is necessary to attain a UL94 VO rating. As explained below, a UL94 VO rating is the standard of flame retardancy frequently required by users of flame retarded polymers. A reference describing the VO rating system and other flame retardant ratings is cited below. The ratio of APP to THEIC may be from about 2:1 to about 6:1, but is preferably around 4:1. Thus, based on the weight percent of only these two components, APP may be present in an amount of from about 66 to about 84 percent and THEIC may be present in an amount of from about 34 to about 16 percent by weight based on 100 percent.
The ammonium polyphosphate (APP) used in the invention is a material of formula (NH 4 PO 3 ) n in which n is an integer from about 200 to about 1000 and wherein the APP has a particle size less than 45 microns. An example of an APP useful in the practice of this invention is Exolit® 422 (from Hoechst AG, Frankfurt, Germany), a fine particulate, sparingly water-soluble APP of formula (NH 4 PO 3 ) n , in which n is about 700 and more than 99 percent of the particles are less than 45 microns in size, with a typical average particle size of 19 microns.
The selected silica useful in this invention is, for example, a precipitated silica which is formed by the reaction of an alkaline silicate solution, preferably sodium silicate, with a mineral acid, such as hydrochloric acid, sulfuric acid or nitric acid. The resulting white precipitate is filtered, washed and dried. The resulting precipitate is then characterized by the following tests and the selected silica is chosen on the basis of the values described. The selected silica must have a surface area of at least 450 m 2 /gram as measured by a test called "BET Surface Area Test". The BET Test is done to measure the surface area of silica powders by measuring the quantity of nitrogen gas that adsorbs as a monomolecular layer on the surface of a sample. The selected silica must have a particle size that is less than or equal to (that is, does not exceed) 4.5 microns. It is well known in the art how to select particles to ensure that they do not exceed a certain size. These methods include using mesh screens of selected size to only allow particles of the chosen size limit to pass through. The selected silica must have a tapped density or bulk density of less than or equal to (that is, does not exceed) 80 grams/liter. Tests used to characterize tapped density or bulk density are well known in the art, for example ASTM D 1895 "Standard Test Methods for Apparent Density, Bulkfactor, and Pourability of Plastic Materials". The selected silica must also have a certain oil absorption characteristic. This oil absorption characteristic may be described in several ways, such as by using a Dibutyl Phthalate Absorption Test (DBP Test) to calculate a DBP value, or a Packing Fraction Test (described in Example 21) which uses diatomite and linseed oil to generate an oil absorption value ("Abs"). Of these two tests the DBP test is believed to be more accurate.
An example of a selected silica suitable for use in this invention is FK500LS (Degussa Corporation, Ridgefield Park, N.J.). FK500LS is a precipitated silica having the following typical values: average agglomerate or particle size of 3.5 microns, a pH of 6.5 (5 percent in water), 3 percent moisture (after 2 hours at 1000 degrees), DBP value of 330 percent, and a BET surface area value of 450 m 2 /gram.
The flame retardant polymer systems of this invention may be used in injection molding, thermoforming, extrusion, blow molding and film applications. Examples of articles which may be made include battery cases, appliance housings, wall panels, electronic parts, wire and cable insulation, and similar types of articles, especially articles where flame retardant qualities are important.
Optionally, a pigment selected from the group consisting of SiO 2 , TiO 2 , SnO 2 , ZnO, Sb 2 O 3 , Fe 2 O 3 , ZnBO 3 and PTFE, or mixtures thereof, may be added in an amount of from about 0.5 percent to about 5 percent by weight, and preferably in an amount of from about 0.5 percent to about 3.0 percent. Of these pigments, SiO 2 , TiO 2 , SiO 2 /TiO 2 , ZnO, Sb 2 O 3 , and PTFE are a particular subgroup with TiO 2 being the preferred group. It is preferable to use at least one of these additional pigments in the polymer systems of this invention. These particular pigments are believed to enhance the flame retardance of the polymer systems described in this invention. One can use one pigment selected from the group or a mixture of two or more of these pigments. If mixtures are used, such mixture may be made by using the same or different amounts of the pigments selected. For example, one can use a mixture of one percent SiO 2 and one percent TiO 2 . For example, one can also use 0.5 percent PTFE, 1 percent SiO 2 and 1 percent TiO 2 , et cetera.
The compositions of the present invention may also contain dyestuffs, pigments (in addition to those listed above), fillers, fiber-reinforcing agents, lubricants, plasticizers, antistatic agents and stabilizers.
The polymer compositions of the present invention may be prepared by conventional methods known to those skilled in the art. The flame retardant components may be mixed separately and then added to the polymer, or added to the particulate polymer which is mixed to form a uniform blend; the mixture may be melt blended in an extruder and formed into pellets. Alternatively, the blend may also be fed directly to a molding machine such as a screw injection molding machine. Another method includes the formation (for example in a Banbury mixer or extruder) of a master batch in the form of pellets or particles containing a higher concentration of the flame retardant than is desired in the final polymer system. The master batch material may then be blended with more polymer and processed as described above.
For a general description of processing plastic materials see Processing of Thermoplastic Materials, edited by Ernest C. Bernhardt, Reinhold Publishing Corp., 1967.
The flame retardancy of the polymer systems of this invention may be evaluated using the Underwriters' Laboratory Procedure entitled "Test for Flammability of Plastic Material-UL94", such as the one dated May 12, 1975 ("UL94") and American Society for Testing Materials ANSI/ASTM D 2863-77, entitled "Standard Method for Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index)", published September, 1977 ("D 2863"). These procedures are incorporated by reference herein.
TEST METHODS
The following DBP and BET test methods have been used by Degussa Corporation in characterizing some of their materials.
DBP Test Method
Approximately 12.50 grams (plus or minus 0.01 g) of sample (such as silica) are weighed out on an analytical balance in an appropriately sized container. The sample is then placed into a mixing head which has been positioned on a Brabender Plasti-Corder® mixer (model #EPL-V3302, available from C. W. Brabender Inc., Hackensack, N.J.).
Note that all equipment must be completely dry before starting the procedure. The cover is placed over the mixing head and a burette (Constant Rate Burette from Cabot) (calibrated to deliver 4.0 ml/minute of dibutyl phthatlate (DBP)), is properly aligned over the top of the cover, and is filled with dibutyl phthalate (reagent grade from Baker). The mixer is then turned on and checked to be sure that the mixing blades are rotating at exactly 125 revolutions per minute and that the torque reading is zero. The burette is turned on to begin delivery of the DBP and the torque reading is monitored. At a value of 62 newton-meters the burette is turned off and the volume of DBP delivered is recorded (plus or minus 0.01 ml). The DBP Absorption Value (DBP-Abs) can be calculate by using the following equation: ##EQU1## Alternatively, this information may be furnished in the trade literature for the particular material. For example, Degussa gives this information.
BET Test
The surface area of silica powders may be measured by measuring the quantity of nitrogen gas that adsorbs as a monomolecular layer on the surface of a sample of silica. A sample of silica between 0.05 to 0.15 grams (plus or minus 0.0001 g) is weighed into a tared glass tube with caps (#230/61002/00, from Micromeritics) and the weight of the whole assembly is recorded. The caps are then removed and the glass sample tube is placed into the metal sample holder of a Flowsorb II 2300 (R) instrument (Micromeritics Instrument Corporation, Norcross Springs, Ga.) and plugged into the DEGAS outlet. The empty sample tube and holder assembly are on the TEST outlet. A heating mantle is placed over the holder assembly containing the sample and the heater is set to a temperature of 160 degrees C. for 20 minutes. When completed, the holder assemblies are reversed so that the holder containing the sample is now located in the TEST outlet. The gas flow is readjusted to 62 if necessary. The liquid nitrogen in the cold trap Dewar flask is initially full. The DET button is then depressed. The instrument will count the air pulse and then return to a value of 0.02 or less. The Dewar of liquid nitrogen is then placed under the sample. The sample is immersed by lifting up the Dewar tray until it locks with a click. After the DET display returns to 0.02 or less, the CLEAR S.A. DISPLAY button is pushed. The SURFACE AREA button is then pushed so that the display reads 0.00. Then the RELEASE button is pushed and the liquid nitrogen is removed. The sample is warmed with a beaker of water. The gas flow returns to the line and the THRESHOLD light begins blinking. Counting will appear on the digital display. After the counting stops, the SURFACE AREA button is pushed and the result on the display is read. The surface area (in square meter/gram) may be calculated by using the following equation. ##EQU2## Alternatively, this information may sometimes be obtained from the supplier of material.
EXAMPLES
The following nonlimiting examples are intended to be illustrative of the invention. Unless otherwise indicated, chemical symbols have their usual meaning, C means degrees Centigrade, g means grams, ml means milliliter, M-g means meter-gram, mm means millimeter.
EXAMPLE 1
Polypropylene (43.8 g of Profax 6323 from Himont, Wilmington, Del.); ammonium polyphosphate (12.0 g, Exolit® 422 from Hoechst AG); THEIC (3.0 g); TiO 2 pigment (0.6 g, rutile grade, type R101 from DuPont, Wilmington, Del.); and silicon dioxide (0.6 g, type FK500LS from Degussa Corporation) were mixed by hand in a 150 ml plastic beaker. The materials were then compounded using a Brabender torque rheometer fitted with a Banbury type mixer. The materials were compounded at 170 to about 190 degrees C. and mixed until the torque reached a constant value (about 5 M-g). The polymer melt was then removed from the mixer and put into a compression mold (ANCO TOOL, East Providence, R.I.) having a cavity 5 inches by 5 inches by 1/16 inch (127 mm by 127 mm by 1.6 mm) with a highly polished surface. The mold was pressed using a hydraulic press having flat horizontal platens (Carver press) with heated surfaces at 170-190 degrees C. The mold was then removed and put in a Carver press with a water-cooled surface. The mold was left in this press under about 10,000 pounds of pressure (45,000 newtons) for about 5 minutes and then removed. The cooled plastic plaque was then cut into strips which measured 5 inches by 1/2 inch (127 mm by 12.7 mm) using a Twing Albert film cutter. These strips were then used for testing in the Underwriters' Laboratory vertical test cabinet described in UL94 and in the Oxygen Index apparatus described in the ASTM test D 2863.
EXAMPLE 2
The procedure described in Example 1 was repeated, except that 40.8 g of polyethylene (type NA203 from VSI, a division of Quantum Chemicals, Streamwood, Ill.) were used instead of polypropylene; 14.4 g of APP (Exolit® 422) were used instead of the amount in Example 1; and 3.6 g of THEIC were used instead of the amount in Example 1. The TiO 2 and silicon dioxide used were the same as in Example 1.
EXAMPLE 3
The procedure described in Example 2 was repeated except that PTFE was used in the same amount instead of TiO 2 .
EXAMPLE 4
The procedure described in Example 2 was repeated except that SnO 2 was used in the same amount instead of TiO 2 .
EXAMPLE 5
The procedure described in Example 2 was repeated, except that ZnO was used in the same amount instead of TiO 2 .
EXAMPLE 6
The procedure described in Example 1 was repeated except that 43.8 g of ethyl vinyl acetate polymer (Elvax 660 from DuPont) were used instead of polypropylene.
EXAMPLE 7
The procedure described in Example 1 was repeated except that 45.0 g of polypropylene were used instead of the amount in Example 1, and TiO 2 and SiO 2 were not added.
EXAMPLE 8
The procedure described in Example 2 was repeated except that 42.0 g of polyethylene were used instead of the amount in Example 3, and TiO 2 and SiO 2 were not added.
EXAMPLES 1A-8A
The products of Examples 1-8 were made into test strips as described in Example 1. A test for VO ratings as described in the UL94 standard and a test for Oxygen Index as described in ASTM D 2863 were conducted on the strips. Three strips were tested for each of the Examples 1-8. The average of the values obtained are shown in Table I.
TABLE I______________________________________Example UL94 Oxygen Index______________________________________1A V0 31.52A V0 35.53A V0 28.54A V0 29.05A V0 32.06A V0 29.07A V2 28.58A V2 27.2______________________________________
EXAMPLES 9-17
Examples 9-17 and Table II illustrate the reduction in bloom which may be observed in using this invention versus other additives. These examples are not intended to be limiting.
EXAMPLE 9
Polypropylene (43.8 g of Profax 6323); APP (12.0 g of Exolit® 422); THEIC (3.0 g); titanium dioxide pigment (0.6 g of R101 from DuPont); and silicon dioxide (0.6 g of a fumed silica, type Aerosil 200 from Degussa Corporation) were combined by hand in a 150 ml plastic beaker. The materials were then compounded using a Brabender torque rheometer fitted with a Banbury type mixer. The materials were compounded at 170 to about 190 degrees C. and mixed until the torque reached a constant value of about 5 M-g. The polymer melt was then removed from the mixer and put into a compression mold (ANCO TOOL) having a cavity 5 inches by 5 inches by 1/16 inch (127 mm by 127 mm by 1.6 mm) with a highly polished surface. The mold was pressed using a Carver press with heated surfaces at 170-190 degrees C. The mold was then removed and put in a Carver press with a water-cooled surface. The mold was left in this press under about 10,000 pounds of pressure (45,000 newtons) for about 5 minutes and then removed. The plates were then separated and the resulting plastic film was peeled from the plate. The residue remaining on the stainless steel polished surface was then noted. The results of material made in this Example 9 were compared to a standard known as "30 percent IFR10". This IFR 10 standard was made by mixing APP, THEIC and melamine cyanurate in a ratio of 3:1:1. Thirty percent means 30 percent by weight of this mixture.
This rating system is a subjective assessment which generally follows the following criteria. A rating of 5 to 6 is equivalent to a dull waxy appearance on the entire face of the polished mold. This deposit is thin but covers the entire surface of the mold. A rating of zero would be given to a surface showing no deposit at all on the polished surface. A rating between zero and six would be given if the surface had a deposit that covered only portions of the surface but not the entire surface. (The higher the amount of surface covered, the closer the value would be toward 6). A rating of greater than 6 would be used for surfaces having a thicker layer of deposit covering the entire surface of the mold. A reading of between 0 and 3 is preferred with a zero rating being the best rating.
EXAMPLE 10
The procedure described in Example 9 was repeated except that the SiO 2 used was a precipitated silica with an oil absorption value of 260% (Sipernat 22, Degussa).
EXAMPLE 11
The procedure described in Example 9 was repeated except that the SiO 2 used was a precipitated silica with an oil absorption value of 270% (Sipernat 22S Degussa).
EXAMPLE 12
The procedure described in Example 9 was repeated except that the SiO 2 used was a precipitated silica with an oil absorption value of 330% (FK500LS, Degussa).
EXAMPLE 13
The procedure described in Example 9 was repeated except that the SiO 2 used was a precipitated silica with an oil absorption value of 340% (Sipernat 50, Degussa).
EXAMPLE 14
The procedure described in Example 9 was repeated except that the SiO 2 used was a precipitated silica with an oil absorption value of 330% (Sipernat 50S, Degussa).
EXAMPLE 15
The procedure described in Example 9 was repeated except that the SiO 2 used was a fumed silica (Aerosil 972, Degussa).
EXAMPLE 16
The procedure described in Example 9 was repeated except that 42.6 g of polypropylene were used instead of the amount in Example 9; and 1.8 g of SiO 2 (type FK500LS from Degussa) were used instead of the type and amount of SiO 2 listed in Example 9.
EXAMPLE 17
The procedure of Example 9 was repeated except that 44.4 g of polypropylene were used instead of the amount in Example 9; and no SiO 2 was added.
EXAMPLES 9-17: RATINGS
The appearance of the plates resulting from the procedures described for Examples 9-17 were evaluated by rating the appearance of the plates, with 0 equal to no plate out and 10 equal to the worst plate out. The results are shown in Table II.
TABLE II______________________________________ Plate Out RatingExample (0 = none, 10 = worst)______________________________________ 9 2.510 4.511 6.512 1.513 4.014 3.015 2.516 0.017 5.0______________________________________
EXAMPLES 18-32
The following examples illustrate how absorbent materials can be identified using a test called the Packing Fraction Test. This test is used to measure the amount of free volume the silica contains. A large free volume is preferred, such as in the range of 0.8-1.0.
EXAMPLE 18
Diatomaceous earth (also called diatomite) (5 g of Celatom MW27 from Eagle Picher Inc., Reno, Nev.) were placed on a flat black Formica® laminated plastic sheet. Drops (enough to give a glaze) of linseed oil from a pipette were slowly dripped onto the powder. After every few drops the oil was worked into the powder using a spatula. This process was continued until a glaze was noted on the surface of the powder/oil blend. The presence of such a glaze indicates the end point at which all the oil that could be absorbed into the powder has been absorbed into the powder. The volume of oil absorbed (Abs) is represented by the following formula: ##EQU3## where Vb equals the beginning volume of linseed oil in the pipette, Vf equals the final volume of linseed oil in the pipette, W equals the weight of the powder in grams, and sg equals the specific gravity of the powder in g/cc. The Abs value is recorded in Table III. This test may also be used with silica.
EXAMPLE 19
The procedure described in Example 18 was repeated except that 5 g of diatomite (Celatom MW25, Eagle Picher) with an average particle size of 8-10 microns were used instead of the MW27 grade. The Abs value is recorded in Table III.
EXAMPLE 20
The procedure described in Example 18 was repeated except that 5 g of diatomite (Celatom MW12, Eagle Picher) with an average particle size of 24 microns were used instead of the MW27 grade. The Abs value is recorded in Table III.
EXAMPLE 21
The procedure described in Example 18 was repeated except that 5 g of diatomite (Celatom WEBH1, Eagle Picher), a low bulk density material, were used instead of the MW27 grade. The Abs value is recorded in Table III.
EXAMPLE 22
The procedure described in Example 18 was repeated except that 5 g of diatomaceous earth (Superfine superfloss, Manville, Corporation, Denver, Colo.) were used instead of the MW27 grade. The Abs value is recorded in Table III.
EXAMPLE 23
The procedure described in Example 18 was repeated except that 5 g of SiO 2 . (Aerosil 200 from Degussa Corp.) were used instead of the diatomite. The Abs value is recorded in Table III.
EXAMPLE 24
The procedure described in Example 18 was repeated except that 2 g of silica (Sipernat 22 from Degussa Corp.) were used instead of the diamomite. The Abs value is recorded in Table III.
EXAMPLE 25
The procedure described in Example 18 was repeated except that 2 g of silica (Sipernat 22S from Degussa Corp.) were used instead of the 22 grade. The Abs value is recorded in Table III.
EXAMPLE 26
The procedure described in Example 23 was repeated except that 2 g of silica (Sipernat FK500LS from Degussa Corp.) were used instead of the 22 grade. The Abs value is recorded in Table III.
EXAMPLE 27
The procedure described in Example 24 was repeated except that 2 g of silica (Sipernat 50 from Degussa Corp.) were used instead of the 22 grade. The Abs value is recorded in Table III.
EXAMPLE 28
The procedure described in Example 23 was repeated except that 2 g of silica (Sipernat 50S from Degussa Corp.) were used instead of the 22 grade. The Abs value is recorded in Table III.
EXAMPLE 29
The procedure described in Example 18 was repeated except that 2 g of silica. (Novacite L337 from Malvern, Inc., Hot Springs, Ark.) were used instead of the diatomite. The Abs value is recorded in Table III.
EXAMPLE 30
The procedure described in Example 18 was repeated except that 5 g of sodium silicate (Drymet from Crossfield Chemicals, Inc.) were used instead of diatomite. The Abs value is recorded in Table III.
EXAMPLE 31
The procedure described in Example 18 was repeated except that 5 g of sodium silicate (Crystamet 20-40 from Crossfield Chemicals, Inc.) were used instead of diatomite. The Abs value is recorded in Table III.
EXAMPLE 32
The procedure described in Example 20 was repeated except that 5 g of silica (Aerosil 972 from Degussa Corp.) were used instead of diatomite. The Abs value is recorded in Table III.
TABLE III______________________________________Example Abs Value______________________________________18 .76619 .75720 .78121 .77122 .72523 .90924 .85125 .88926 .89827 .89828 .89029 .58330 .39031 .28632 .952______________________________________
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An improved flame reardant polyolefin is disclosed which comprises a combination of ammoniumm polyphosphate; tris(2-hydroxyethyl) isocyanurate; and a selected silica in an amount from 0.5 percent to an amount equal to one-half the amount by weight of THEIC, wherein the silica meets defined surface arera, particle size and absorption criteria.
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[0001] The invention is in the field of databases and data manipulation, or On-Line Analytical Processing (OLAP), particularly in the area of decision support systems (DSS) used for corporate planning and forecasting.
BACKGROUND
[0002] In well-run organisations, plans made by senior management are based on information passed to them by subordinates. All levels of the management of an enterprise might have access to a data repository containing information about the history of the business, sometimes known as a data warehouse.
[0003] Business planning applications, among them budgeting and forecasting, are increasingly being integrated into an advanced data warehouse solution in order to maximize the payback of the considerable investment in both the computing facilities and the gathering of the data they contain. Data warehousing enables a company to eliminate an extensive amount of workload generated by various reporting tasks. It also facilitates the standardization of data throughout the organization. The company-wide use of such applications results in improved internal communications and more efficient team work.
[0004] In dimensional modeling, a data warehouse contains different dimensions and a fact set related to the business structure. Each dimension represents a collection of unique entities that contribute to, and participate in, the fact set independent of entities from another dimension. The fact set also usually contains transactional data where each transaction is identified by a combination of entities, one from each dimension. Within a data warehouse, each dimension is a table where each record contains a key (or a composite key) to uniquely identify each entity and a list of attributes to qualify or describe the corresponding entity (or key). Each fact record in the fact table contains a foreign key to join to each dimension as well as a list of those measures representing the transactional data.
[0005] In its usual form such a data warehouse provides the following potential business benefits, among others:
[0006] Assist in identification and understanding of business trends and risks
[0007] Assist in identification and understanding of customer behaviour
[0008] Assist in improvement in the quality of forecasts
[0009] Enabling customer segmentation
[0010] Improvement in customer profitability
[0011] Improving product and service quality
[0012] Enabling smarter marketing and targeting
[0013] Optimizing the use of resources
[0014] Typically, data warehousing overcomes the conflicts between information requirements and the current operational databases by copying data from the operational or transactional system, often transforming them into a more usable format, and storing them in a separate database optimized for supporting analytical users—so-called Online Analytical Processing (OLAP) and Multi-dimensional OLAP (MOLAP).
[0015] Multidimensional navigation and data analysis allow users the freedom to make effective use of the large quantity of data stored in a data warehouse. For example, sales performance may be viewed by company, division, department, salesperson, area, product and customer. Thus, the user can “turn the database cube” to view the information from a variety of desired angles or perspectives, first by department and then by area, for example. A ‘drill-down’ function allows the user to select a specific area (geographic) of interest and break it down further by product. Further drill-down on a specific product lets the user explore sales by period.
[0016] The above is more fully and clearly described in “An Introduction to Database Systems” by C J Date, 7 th Edition, 2000, Chapter 21 Decision Support, pp 694-729.
[0017] The basic idea of OLAP is that users should be able to manipulate enterprise data models across many dimensions to understand changes that are occurring.
[0018] Business planning applications, among them budgeting and forecasting, are increasingly being integrated into an advanced data warehouse solution in order to maximize the payback of the considerable investment in both the computing facilities and the gathering of the data they contain. Data warehousing enables a company to eliminate an extensive amount of workload generated by various reporting tasks. It also facilitates the standardization of data throughout the organization. The company-wide use of such applications results in improved internal communications and more efficient team work.
[0019] The deployment of wide area networks, in particular the internet and its enterprise-wide equivalents, has resulted in the potential for revolutionary changes in the way enterprises manage their business internally. For example, a primary advantage of a web-based budgeting application is that it permits and encourages high participation throughout an organization. Users can access the application from around the world, at the appropriate level of detail and security, allowing organizations to adapt quickly and to make rapid changes to their goals and strategies. All relevant employees can participate directly in the budgeting process so that plans are developed using information from those who are actually involved in that area of the business. Users simply enter the data relevant to their function, and a calculation engine automatically generates the corresponding financial data after confirming its compatibility with other related data, and integrating it with that other data. This means that upper management can gain a better understanding of the business unit managers' forecasts and the assumptions underlying them.
[0020] Upper management is responsible for the strategic goals of the organization and must often explore so-called “what-if” scenarios. The business unit managers, on the other hand, are responsible for reaching these goals through revenue improvement, cost control, and resource allocation. Through web-based budgeting applications, upper management can set goals and priorities in the system to encourage the accomplishment of required objectives. As well, upper management can input standard rates or key planning assumptions such as salary grade levels, product prices, production capacity, inflation rates, and foreign exchange rates to ensure consistency throughout the plan. Business unit managers together with their upper management can, through a series of iterative steps, develop a plan that is aligned with the strategic goals of the organization. Thus a web-based budgeting application bridges the gap between upper management and the business unit management.
[0021] Although a number of products address some of the needs for putting together plans for large enterprises, they each have their shortcomings. Examples are “CONTROL” 1 by KCI Computing, Inc. of Torrance, Calif., and “e.Planning” 2 by ADAYTUM of Bloomington, Minn. None of these products have the ability to allow multiple alternate plans to be presented to a superior before selection and rollup into that superior's plan. They are all restricted in their ability to allow roles to have significant complexity in more than one dimension.
SUMMARY OF INVENTION
[0022] What is needed is a set of improvements in automated planning and budgetary processes so that such processes allow subordinates' plans to be more effectively incorporated into those of their managers.
[0023] Definitions
[0024] It is helpful to remind the reader of some basic definitions used in the art. The reader is cautioned that in some cases terms are almost synonymous, in others, they have evolved different meanings over time and between different developers.
[0025] A cube: A multi-dimensional set of data.
[0026] A plan: That which the enterprise uses to assist in determining the decisions for the future—derived from one or more cubes of the planning data repository.
[0027] A sub-plan: A portion of a plan or sub-plan within the domain of a responsible manager.
[0028] Delegation: 1) The process of assigning sub-plans to subordinate managers and passing sub-plans to those managers. 2) The further process of integrating sub-plans into a single plan, including ensuring overall consistency of the data, and conformance with any constraints defined by users. The meaning is defined by context.
[0029] Proposal: A version of a sub-plan capable of being updated (the result of working on a sub-plan).
[0030] The invention makes use of a Planning Data Repository (PDR). Although similar to a data warehouse, a PDR differs in that a data warehouse, by definition, contains (only) non-volatile, time-variant, historical data stored in support of management decision-making, whereas a PDR allows changes to be made to virtually any data item. These data are organized and summarized into a multidimensional structure defined by a set of dimensions and measures. Typically, a PDR is generated by making a copy of a data warehouse then adding further fields and schemas related to such items as forecasts and the organizational structure. Thus, in addition to the historical data, a PDR may also contain information related to forecasts and alternative business options/strategies.
[0031] A ‘sub-plan’ which is a subset of the coherent set of data contain in a ‘plan’, is usually constructed from a data warehouse, or in this case a Planning Data Repository (PDR). In the business decision support system (DSS) environment, plans, in the form of sub-plans (called proposals) of the PDR with data modified by subordinates, are incorporated into higher level proposals (and ultimately the master plan) by their superiors, usually with increasing levels of summarisation, but retaining the necessary precision.
[0032] Modelers can only create Dimensions, Cubes, and Datalinks. They can also create and deliver plans from Cubes. Modelers can not create Organizations or Delegations. A Plan Manager can create Delegations and Organizations. A Contributing Manager can only create Delegations.
[0033] Subplans are read only objects. Proposals are updatable versions of subplans. Only proposals can be modified, extended, returned, accepted or rejected.
[0034] As enterprises grow, it becomes increasingly difficult to assemble comprehensive plans, and at the same time maintain the overall integrity and consistency of the underlying data. In previous systems, higher level plans were based solely on data extracted from subordinate plans, but the direct linkage to the underlying data is then lost. Further, the complexity of the planning process, with its need for close coordination between the users, has previously made it impractical to permit subordinates to contribute more than one version of their plan to the higher levels.
[0035] Here, the invention allows several users to manipulate complex data interactively, but separately, and then have the results of their inputs merged. Previous systems did not provide a means to allow a manager to selectively incorporate sub-plans produced by others (subordinates) in an interactive and iterative manner. The invention is based on hierarchical planning which matches typical business environments. The planning process is distributed over the management hierarchy and each level may contribute one or more alternative plans for consideration by a superior level. The distribution of the process is carried out using computer-enabled ‘delegation’.
[0036] Further the invention allows for the specification of relationships between a dimensional structure and a responsibility structure such that sub-plans and plans using the dimensional structure of the PDR may be partitioned into components corresponding to the responsibility structure. This specification defines an Organisation.
[0037] In the invention, part of ‘delegation’ is the process of setting up the conditions, requirements, etc. for a subordinate to draft one or more sub-plans for their particular area. The subordinate then submits one or more of these sub-plans based on these conditions and information in the PDR, as well as on their specific experience and other (local) input. Such input may include submissions from subordinates obtained through this same delegation process. On ‘submission’, this sub-plan is able to be incorporated into higher level sub-plans (and ultimately into the master plan) (‘accepted’) or it might be returned to the subordinate for further work (‘rejected’) and potentially resubmitted. It is during this submission process that the second part to of ‘delegation’ takes place—the process of integrating sub-plans into a single plan, including ensuring overall consistency of the data, and conformance with any constraints defined by users. The process is iterative in nature, wherein information and planning data or forecasts, in the form of subordinate sub-plans contributed by others, are selectively incorporated in higher level plans. It is also re-entrant, in that the same process or set of processes may be used for successively higher and lower levels of planning.
[0038] It is important to achieve consistency across all of the data in the PDR and this function is carried out by some form of calculation engine. In designing and implementing the calculation engine considerable skill and experience is needed to set up a suitable data model (being the numbers and the relationships between those numbers) which will satisfy the guiding principles of the planning and calculation processes; namely:
[0039] Mathematical correctness
[0040] Fairness in apportioning changes across several variables
[0041] Minimum change to data.
[0042] In addition other attributes must be taken into account by the calculation engine and other systems; such as the ability to provide for Cell Locking so that the calculating engine may not change a value in a locked cell.
[0043] These principles, combined with a set of prioritised rules for dealing with how functions are applied to cells, or how cells containing altered parameters influence cells containing calculated results where there are ‘competing’ demands for fairness and correctness because of the complexity of relationships in multi-dimensional data, are important in ensuring the successful application of the invention. The degree of sophistication of these rules, and hence the calculation engine, affect the flexibility of the overall process and the potential complexity of the system which can be modelled, but not the underlying principle.
FIGURES
[0044] The invention will be described with reference to the following figures:
[0045] [0045]FIG. 1 shows a typical environment within which the invention is practiced.
[0046] [0046]FIG. 2 is shows the relationships between various objects.
[0047] [0047]FIG. 3 and FIG. 4 illustrate the hierarchical relationships for reporting structures typical of those used in enterprises.
[0048] [0048]FIG. 5 is a flowchart describing the major steps involved in the ‘using phase’ of the invention.
[0049] [0049]FIGS. 6 and 7 are ‘state-transition’ diagrams referred to in describing parts of the ‘using phase’.
[0050] [0050]FIGS. 8 and 9 are tables which give two examples of organisations in which the invention may be practiced.
DETAILED DESCRIPTION
[0051] A typical network environment is shown in the FIG. 1. In this somewhat simplified depiction the planning data repository 130 , calculation engine 140 , and application 120 are shown in a single location within a Server 105 , and a single client computer 100 is depicted, connected to it over a network 110 . A full implementation may have the planning data repository 130 residing in one or more locations, with the calculation engine 140 and application 120 within the server 105 performing a coordination role. Of course multiple client computers 100 would also be in use simultaneously, connected over one or more networks 110 .
[0052] The process covered by the invention is best described in two phases, namely the ‘Modeling Phase’ and the ‘Using Phase’. The Modeling phase is where the data warehouse schema and its relationship to the business as well as the data warehouse are defined. The Using phase is where the various users of the system provide their input and compare scenarios during budget-setting, etc. Each of these phases is now discussed in more detail.
[0053] Modeling Phase
[0054] In the Modeling phase, the structure of the business or enterprise is considered and defined by an individual or team (the modeler); in other words the relationships between the people managing the enterprise and the data for which they are responsible are recorded.
[0055] The following are the Modeling Steps required to implement the invention:
[0056] 1. Define one or more dimensions (ways of looking at how the company is structured)
[0057] 2. Create a cube by specifying dimensions from a PDR.
[0058] 3. Populate the cube manually or from external sources.
[0059] 4. Define user classes
[0060] 5. Map user classes to the levels in the structures identified by the dimensions to produce an organisation object.
[0061] 6. Repeat steps 4 and 5 as required.
[0062] 7. Create a plan from one or more similar cubes and assign it ownership (user class). Plan creation is the ultimate goal of the modeling phase.
[0063] Referring now to FIG. 2 which formally describes the relationships between various major elements or objects used in the invention. An Organisation Object 210 (also referred to an ‘organisation’ or ‘view’) is defined for the enterprise. An Organisation Object describes how the responsibility for work is allocated. For example, one such Organisation Object might relate the function of each level to product lines, without regard to geographical location, and another to geographical location without regard to product lines. A Delegation object 220 uses an Organisation object 210 and a plan 200 . An organisation object can be referred to by multiple Delegations. By applying an Organisation object to a plan, a Delegation can generate one or more subplans 230 both during the initial distribution of the work, and later, during submission processes as Plans or proposals are passed among the various members of the management hierarchy. A Plan or Sub-Plan 200 (which is referred to as a Proposal once submitted to a superior manager) can be referred to by one or more Delegation objects 220 .
[0064] For each Organisation Object a number of dimensions are considered. These dimensions describe some part of the corporate structure. Further, they define the subset of data contained in the planning data repository (PDR) to be considered during further processing and consideration. It is essential that all of the data required to produce plans for a particular dimension be present in the PDR. A PDR may consist of, or contain, several such plans.
[0065] In the invention, a Sub-Plan is passed from the Plan Manager or a Contributing Manager to a reporting (or delegated) Contributing Manager or Contributor by ‘delegating’ it. In this context, the ‘delegation’ means ‘passing control’ of the sub-plan. A Delegation Object is defined which describes how to take a particular Sub-Plan and relate it to the Organisation.
[0066] A further function carried out in the modeling phase is the definition of a number of User Classes. These are defined as roles performed by managers, rather than specific individuals. Generally, the levels in a structure defined by a dimension are mapped to one of the User Classes, although not all levels need be mapped, depending on the requirements of the planning process. By this means, a User class defines the role of the person or group and, through one or more Delegation Objects; the one or more sub-plans for which they are responsible
[0067] [0067]FIGS. 8 and 9 are tables which give two examples of Organisation structures relevant to the same enterprise. In the FIG. 8, part of the main management structure is shown. Each Organisation level shown in column 800 may have related User Classes as shown in column 801 by specific User Classes. Each of the rows, 810 , 811 , 812 , 813 relates to a particular function in the corporation. For example, Corporate Sales, North American Sales, and European Sales 821 , which are obviously related, use three different User Classes, c, h and i, 831 respectively. In the FIG. 9, other parts of the management structure are shown in relation to part of the main management structure. Each Organisation level shown in column 900 may have related User Classes as shown in column 901 by specific User Classes. Again, each of the rows, 910 , 911 , relates to a particular function in the corporation. For example, Computing Expense—Corporate, Computing Expense—North America, and Computing Expense—Europe, 921 , which are obviously related, use three different User Classes, m, p, and q, 931 respectively.
[0068] Thus the table of FIG. 8 relates the various parts of the enterprise involved in manufacture, sales, marketing and research in the various geographic regions, and the table of FIG. 9 relates those parts of the enterprise concerned with computing, both capital and expense, again for the various geographic regions. Although the organisations are somewhat orthogonal, they will have some data in common, since, for example, the marketing divisions of the enterprise will make use of computing resources and must make some provision in their planning process for covering the costs involved. In this case the only common element is Corporate Management—User Class a, which presumably dictates this aspect of the plan. Other examples might have more than one common element (and User Class).
[0069] [0069]FIG. 3 shows the relationships between various groups or roles for a simple three level hierarchy. The structures defined or described by a given dimension are strictly hierarchical and generally each level of the hierarchy is a member of one of the following groups:
[0070] Plan Manager 300 (PM)
[0071] Contributing Manager 310 (CM) (both manages others, and is managed by, and contributes to, someone above—who may be another Contributing Manager 310 or the Plan Manager 300 )
[0072] Contributor 320 (C) (is managed by, and contributes to, someone above—who will be a Contributing Manager 310 , or possibly the Plan Manager 300 )
[0073] [0073]FIG. 4 shows relationships for a more complex hierarchy where some parts of the reporting structure have as many as five levels from the Plan Manager 400 through Contributing Managers 410 , 420 , 430 to a Contributor 440 , and others as few as two where a Contributor 450 reports directly to the Plan Manager 400 . Such hierarchies may be arbitrarily deep, and complex, but in all cases there must be a clear reporting structure, such that each Contributor or Contributing Manager reports upwards to only one Contributing Manager or the Plan Manager.
[0074] Using Phase
[0075] In the ‘using’ phase, a delegated Contributing Manager (CM) or Contributor is asked to produce one or more sub-plans each of which is within their responsibility. These sub-plans are effectively ‘proposals’ for the planning process, and the CM or Contributor may choose to pass one, all or some of the proposals to their manager in turn through the ‘delegation’ process. The manager can then accept or reject any of the proposals in turn. Those that the manager accepts can be incorporated in the sub-plan for which the delegating manager is responsible.
[0076] A superior may change the information in a sub-plan before incorporation in their own sub-plan. Their sub-plan, with any changes included, is in turn passed on to their superior manager.
[0077] A number of iterations of these steps may take place before a CM or Contributor in turn passes one or more sub-plans to their superior CM or the Plan Manager (PM).
[0078] Similarly, the PM can select from alternate sub-plans offered by subordinates by accepting or rejecting them in turn. The PM may then further modify a sub-plan before integrating it into the master plan.
[0079] A typical sequence of events during the using phase of delegation is now described with reference to the flowchart of FIG. 5. Once the reporting structure (in the form of an Organisation Object) has been added to the planning data repository (PDR), a series of ‘delegations begins, starting at the Plan Manager (PM). The delegated Contributing Managers (CM) or Contributors reporting directly to the PM will normally ‘Accept’ the delegation 510 and prepare one or more sub-plans 520 for the part of the organisation for which they are responsible. The sub-plans are then submitted to the superior CM or the PM 530 . At this stage the second part of the delegation process comes into operation in the form of a calculating engine which, under the control of the application software must determine whether the changes made in the sub-plan are compatible with other data in the PDR 540 , particularly with overlapping sub-plans. If they are incompatible, the submitting delegated CM or Contributor must prepare alternate plans 520 and resubmit. This cycle will continue until acceptable sub-plans are submitted.
[0080] The superior CM or the PM must then decide whether to accept the sub-plan 550 . If it is not acceptable, again the submitting delegated CM or Contributor must prepare alternate plans 520 and resubmit. Again, this cycle will continue until sub-plans acceptable to the superior are submitted.
[0081] In some cases the superior CM or PM might make some changes 560 . Potentially, a similar series of cycles might take place within the system to ensure that the sub-plans as amended by the CM or PM are compatible with other data in the PDR as before and when satisfactory, the sub-plan as submitted and amended is integrated with the superiors plan 570 . This ends one iteration for a particular Superior CM and their reporting delegated CM or Contributor.
[0082] This sequence might also take place during the preparing one or more sub-plans step 520 , as the CM may delegate a subset of the sub-plan to a reporting delegated CM or Contributor. This demonstrates how the sequence is both iterative and re-entrant.
[0083] We turn next to FIG. 6, which shows the possible states and transitions for Delegation Objects—their ‘life-cycle’. When a Delegation Object is ‘Created’ 604 it moves from ‘Doesn't Exist’ 600 to ‘Available’ 610 , when it is ‘Run’ 614 it moves to ‘Active’ 620 and finally, when ‘Closed’ 622 it moves to ‘Completed’ 630 after which it is ‘Deleted’ 632 and moves to ‘Doesn't Exist’ 600 . When ‘Run’ 624 is applied to a ‘Completed’ 630 delegation, it returns to the ‘Active’ 620 state. ‘Refresh’ 626 and 634 updates all sub-plans with current plan data. Users are notified of the change so that they might review the consequences. ‘Close’ 622 will mark all sub-plans as closed. No proposals can be returned from ‘closed’ sub-plans, although the action of ‘Running’ 624 or ‘Deleting’ it 632 can be used to reactivate a sub-plan, allowing it to be further changed. ‘Cancel’ 612 is an extreme action used only when the all audit information for a delegation is to be deleted. Optionally, ‘Cancel’ 612 may cause all delegated sub-plans to be deleted also. Each of the actions (transitions) may optionally cause users to be notified when they take place.
[0084] Finally, we turn to FIG. 7 which shows the possible states and transitions for a sub-plan during the using phase. The normal progress is for a sub-plan to be created when it is ‘Saved’ 702 from ‘Doesn't Exist’ state 700 to ‘Exists’ state 710 , be ‘Returned as tentative 714 (i.e. proposed for adoption) by a delegated Contributing Manager or Contributor as first ‘Tentative’ 720 then, either once ‘Accept as Final’ 724 is issued by the superior manager, it is marked ‘Accepted as Final’ 740 , or it may be that the superior manager issues ‘Accept as Tentative’ 722 first, and moves to ‘Accepted as Tentative’ 730 then following an ‘Mark as Final’ 732 it is marked as ‘Accepted as Final’ 750 . However, as is shown, other more circuitous routes to acceptance may also occur. It should be noted that:
[0085] A sub-plan can have any number of proposals.
[0086] A proposal can be ‘extended’ to give more detail on particular entries in a given sub-plan.
[0087] Any number of proposals can be ‘returned as tentative’.
[0088] Returned proposals are read only, and the ‘extended’ detail is suppressed.
[0089] Only one proposal can be ‘returned as final’. Any existing final proposal gets automatically downgraded.
[0090] Once a proposal is ‘accepted as final’, no further proposals can be returned.
[0091] ‘Reject’ will reject all returned proposals for a given sub-plan.
[0092] In order to facilitate the maintenance of current data in the various sub-plans, the system includes the following commands in the appropriate contexts:
[0093] ‘Refresh Sub-plans’, which updates all dependent sub-plans with current plan data.
[0094] ‘Refresh from Plan’, which updates the selected sub-plan with current plan data.
[0095] Any changes to figures within a proposal or sub-plan must be subjected to examination to ensure complete consistency across all of the data before being consolidated in the manager's sub-plan. Thus the integration of the planning sub-plans which intersect must also be subjected to similar scrutiny before the integration can be completed. This step may be arbitrarily complex, and may include elements based on experience, as well as a thorough understanding of the construction of the model relating all of the data. The complexity is a function of the underlying calculation engine. If a relatively unsophisticated calculation engine is used, then the step may be somewhat simpler, although the flexibility of the planning process will be limited.
[0096] Calculation Engine
[0097] The calculation engine used during the delegation process influences the scope of the changes and extent of forecasting that may be accomplished. For best results such a calculating engine should support Back calculation, cell locking during recalculation, as well as the normal mathematical and statistical functions. A co-pending application “A Calculation Engine for use in OLAP environments”, Jim Sinclair, Bob Minns, Dave Edmunds, Cognos Incorporated, Attorney/Agent Ref# 08-886651, disclosure of which is incorporated herein by reference, describes a suitable calculation engine. The advantage of the calculation engine described therein lies in the ability to identify, before a step of back-solving and/or forward-solving, the subset of cells that needs to be recalculated. This is done using parent/child tables which simply identify and record the fact that the value in a particular cell depends on a value in one or more other cells. Once such parent/child tables exist, it is much simpler and faster to scan these tables looking for potential dependencies than to look at the actual formulae or functions relating the cells. The result is that there is the potential for huge savings in computing resources required to reach a solution in those situations where the cubes are very large, since in general, the number of cells actually affected by a given set of relationships is much smaller than the number of cells in the cube.
[0098] Discussion
[0099] It is therefore one object of this invention to pass data from subordinates to their managers in a form which retains the coupling to the underlying data.
[0100] A further object of the invention is to make it simple for a subordinate to produce more than one version of their sub-plans allowing their superior to integrate those subplans in turn with higher level plans to assess their respective effect. This permits more active and quicker contribution to the ‘what-if’ scenario planning processes taking place at higher management levels.
[0101] It is a still further object of the invention to provide a formal structure and mechanism to define and ‘track’ the decision-making responsibility of an organisation.
[0102] A yet further object of the invention is to provide a means for a manager to ‘drill-down’ from higher level plans to examine in more detail the data previously provided by a subordinate, but viewed in the context of the superior manager.
[0103] In building a business plan, it is helpful to be able to delegate some aspects of these data sources and derived information to others. The invention allows the overall planner or Plan Manager (PM), to take advantage of the local detailed knowledge of subordinates, both delegated Contributing Managers (CM) and Contributors (C), by delegation of part of the planning process to them, and further provides a convenient means to allow alternative sub-plans to be submitted and selectively incorporated or returned for amendment (and potential resubmission). It is this collaborative aspect that is very powerful.
[0104] The invention allows a user to select from a number of alternative sub-plans submitted by subordinates, and optionally incorporate one such selected sub-plan from each subordinate into a higher level sub-plan. Ultimately the master plan produced by the Plan Manager contains data generated by all of the subordinate delegated Contributing Managers and Contributors or the results therefrom.
[0105] ‘Using’ Steps
[0106] The following summarises the steps typically taken in using the invention by various members of the organisation:
[0107] a) For the Plan Manager
[0108] 1. Receive a plan from the modeler.
[0109] 2. Define an organisation to assign responsibility to the plan data, by associating user classes to dimensional hierarchies.
[0110] 3. Define a delegation by associating an organisation to a plan.
[0111] 4. Optionally delegate sub-plans to subordinate delegated Contributing Managers and Contributors
[0112] 5. Receive sub-plans from subordinate delegated Contributing Managers and Contributors as proposals.
[0113] 6. Accept proposals or reject as appropriate. (Proposals may be re-submitted by subordinate).
[0114] 7. Select no more than one accepted proposal from each subordinate and incorporate into own sub-plan.
[0115] 8. Alter any forecast figures in own sub-plan (possibly including figures within areas covered by any subordinates sub-plans)
[0116] 9. Optionally, request subordinate delegated Contributing Managers or Contributors to review changes affecting subordinates sub-plan. (Refresh)
[0117] 10. Optionally, repeat steps 5-7 creating more possible strategies/plans
[0118] b) For Each Contributing Manager
[0119] 1. Receive a (delegated) sub-plan from superior.
[0120] 2. Optionally delegate sub-plans to subordinate delegated Contributing Managers and Contributors.
[0121] 3. Receive a proposal from subordinate delegated Contributing Managers and Contributors.
[0122] 4. Accept proposals or reject as appropriate. (Proposals may be re-submitted by subordinate).
[0123] 5. Select no more than one accepted proposal from each subordinate and incorporate into own sub-plan.
[0124] 6. Alter any forecast figures in own sub-plan (possibly including figures within areas covered by any subordinates sub-plans)
[0125] 7. Optionally, request subordinate delegated Contributing Managers or Contributors to review changes affecting subordinate's sub-plan. (Refresh)
[0126] 8. Optionally, repeat steps 5-7 creating more possible strategies/plans
[0127] 9. Forward one or more sub-plans to superior as proposals.
[0128] 10. Optionally review any suggested changes from superior. (Refresh)
[0129] 11. Optionally review sub-plans rejected by superior and re-submit if necessary
[0130] c) For Each Contributor.
[0131] 1. Receive a (delegated) sub-plan from superior.
[0132] 2. Alter any forecast figures in own proposal.
[0133] 3. Optionally, repeat step 2 creating more possible strategies/plans
[0134] 4. Forward one or more proposals to superior as proposals.
[0135] 5. Optionally review any suggested changes from superior. (Refresh)
[0136] 6. Optionally review proposals rejected by superior and re-submit if necessary.
[0137] Quick Delegation
[0138] In a further embodiment of the invention a quick delegation function is provided so that a PM or CM can forward a plan or sub-plan to a single user class, and have the results returned directly to the forwarding PM or CM, thereby bypassing the use of the organisation object. In all other aspects, the workflow remains the same. This function allows a PM or CM to study a subset of the overall forecast or plan without invoking the full planning delegation process.
[0139] Multi-Level Delegation
[0140] In a yet further embodiment of the invention the distribution of work is carried out bypassing one or more levels of the management hierarchy so that the overall process may get under way more quickly. In this case a superior manager, knowing which user groups are to be involved, arranges for the sub-plans to be directly made available to those user groups. The corresponding merging, or collation, of the results follows the normal hierarchical process described above so that data collection and selection of appropriate sub-plans are controlled by the responsible managers.
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The invention allows several users to manipulate complex data interactively, but separately, and then have the results of their inputs merged. It is based on hierarchical planning which matches typical business environments. The planning process is distributed over the management hierarchy and each level may contribute one or more alternative plans for consideration by a superior level. The distribution of the process is carried out using computer-enabled ‘delegation’. Relationships are specified between a dimensional structure and a responsibility structure such that sub-plans and plans using the dimensional structure of a planning data repository (PDR) may be partitioned into components corresponding to the responsibility structure. Part of ‘delegation’ is the process of setting up the conditions, requirements, etc. for a subordinate to draft one or more sub-plans for their particular area. The subordinate then submits one or more of these sub-plans based on these conditions and information in the PDR, as well as on their specific experience and other (local) input. On ‘submission’, this sub-plan is able to be incorporated into higher level sub-plans. During the submission process sub-plans are integrated into a single plan, ensuring overall consistency of the data, and conformance with any constraints defined by users. The process is iterative in nature.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to US provisional patent application number 21510356, titled ““Mobile airborne vehicles for dynamic video display” filed Feb. 16, 2015 by the applicant.
[0002] This application is related to U.S. provisional patent application No. 62/161,968, titled “Automated Unmanned Aerial and Land Vehicle Applications” filed May 15, 2015 by the applicant.
FIELD OF THE INVENTION
[0003] The present invention relates to using a swarm of unmanned aerial vehicles for horizontal and vertical applications like road lane marking, painting buildings, window washing, construction, crop cultivation/inspection/spraying, etc.
BACKGROUND OF THE INVENTION
[0004] Unmanned vehicles are coming into vogue with their application in military attracting the attention of business' wanting to deploy them to automate manually and time consuming tasks being done today. One such task Is lane marking and painting which is a horizontal application that is done using manual labor or using powered vehicles with many involved in marking the lane. It also takes a long time to mark a lane. Good speeds are about 12 m an hour. It also involves police personnel tied up for hours together, traffic bottlenecks when lane painting is underway, etc. Similarly, sky scraper painting, a vertical application is a very challenging and complex task involving scaffolding or lifts to carry paint workers who have to traverse the length/breadth of the building to paint it. Another horizontal application is in agriculture where crops need to be inspected for diseases, sprayed, watered, etc. These are all done manually as automating them is expensive and hard. Some like watering and spraying are automated but inspection is usually done manually.
[0005] This invention uses a swarm of UxVs (unmanned aerial/ground/hybrid vehicles) to replace the manual and tedious task of these horizontal and vertical applications.
BRIEF DESCRIPTION OF THE INVENTION
[0006] Horizontal applications like lane marking and painting are time consuming and slow today. Similarly vertical applications like painting sky scrapers, etc. are expensive and time consuming. Inspection of crops is still manual and expensive and hard due to labor problems, etc. This invention describes using a swarm of UxVs to disrupt this space by increasing the speed by 10× to 50× or more saving time, labor and costs increasing productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with detailed description, serve to explain the principles and implementations of the invention.
[0008] FIG. 1 —Illustrates the Configuration Management System MCS
[0009] FIG. 2 —Illustrates a flow of the process for a horizontal application, painting/marking
[0010] FIG. 2-1 —Illustrates a continuation of the flow from FIG. 2 for a horizontal application, painting/marking
[0011] FIG. 2-2 —Illustrates a continuation of the flow from FIG. 2-1 for a horizontal application, painting/marking
[0012] FIG. 2-3 —Illustrates a continuation of the flow from FIG. 2-2 for a horizontal application, painting/marking
[0013] FIG. 2-4 —Illustrates a continuation of the flow from FIG. 2-3 for a horizontal application, painting/marking
REFERENCES CITED
U.S. PUBLISHED APPLICATIONS
OTHER REFERENCES
PARENTS CASE TEXT
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] Embodiments of the present invention are described herein in the context of a method and apparatus for emulating a competitive process. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of the disclosure. Reference will now be made in detail to the implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.
[0015] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming, but would nevertheless be routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
[0016] In accordance with the present invention, the components, process steps, and/or data structures may be implemented using various types of operating systems, computing platforms, computer programs, and or/general purpose machines. In addition, those of ordinary skill in the art will recognize that devices of a less general purpose nature such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein.
[0017] A number of terms are used herein to describe features of embodiments of the present invention.
[0018] As used herein, the term “lane marking” will be used to refer to any of a number of formats (known and to be developed) for marking lanes by an operator or user or viewers or vehicle, [etc.] As used herein, the term “lane marking” may be used to refer to painting lanes on roads. The painting may use paint, studs, glow paste, sensors, etc.
[0019] As used herein, the term “painting” will be used to refer to any of a number of formats (known and to be developed) for painting buildings or marking by an operator or user or viewers or vehicle, [etc.] As used herein, the term “painting” may be used to refer to the painting on roads, buildings, etc. The painting may use paint, studs, glow paste, sensors, etc. In an embodiment, painting maybe a series of steps, like first air blowing to clear the target area, a second applying a primer, followed by the paint. In some embodiments, it may also involve stripping or peeling away the existing paint, etc.
[0020] As used herein, the term “inspection” will be used to refer to any of a number of formats (known and to be developed) for inspecting crops, buildings, structures, etc. by an operator or user or viewers or vehicle, [etc.] As used herein, the term “inspection” may be used to refer to the inspection of crops, buildings, bridges, structures, etc. The inspection may use different type of sensors 154 , vision 155 , etc.
[0021] As used herein, the term “spraying” will be used to refer to any of a number of formats (known and to be developed) for spraying crops, buildings, structures, etc. by an operator or user or viewers or vehicle, [etc.] As used herein, the term “spraying” may be used to refer to the spraying of crops, buildings, bridges, structures, etc. The spraying may use different type of sensors, vision for input and spray nozzles and spray for output.
[0022] As used herein, the term “blocks” will be used to refer to any of a number of formats (known and to be developed) for lifting and dropping blocks, etc. by an operator or user or viewers or vehicle, [etc.] As used herein, the term “blocks” may be used to refer to the use of pre-fabricated component blocks used to build buildings, bridges, structures, etc. The blocks may of various formats, etc. and may use different type of sensors, vision for input to drop and align these blocks into position.
[0023] As used herein, the phrase “computer system” is usually made up of a processor, memory, storage, network, clock, input devices and output devices. Input devices can be a keyboard, a pointer device such as a mouse, touch screen, [etc.]. Output devices usually are display, printers, plotters, and controllers, [etc.]. The brain of a computer system is usually the processor such as a microprocessor. A microprocessor executes machine level instructions that enable it to perform logic as well as communicate with the input and output devices. The machine level instructions can be executed with dedicated electronic circuits or use a higher level programmable code that enables the microprocessor to execute a task. The computer system usually at startup, loads an operating system (OS) that manages the input and output devices and also enables executing higher level applications. A server device is a computer based system that usually responds to a client device request. The server device executes a server application that can listen to client requests and respond back with a response. A client device is again a computer based system that communicates across a network with a server device for content. The client device can be a thin client or a thick client. In a thin client, the client device does not handle much processing other than collect input send it across to the server for processing and output the response from the server onto the output devices on the client, like a display, [etc.]. In a thick client, the client device might run an operating system itself, do more processing and communicate with the server device as needed. The communication is usually handled by higher level applications being executed on the client device which make use of networking means to communicate.
[0024] As used herein, the phrase “client device” will be used to refer to the device used by a user with or without a display that communicate with a server device. The phrase “client device” has also been used broadly to refer to client applications executing on the device. The client device can be a general purpose computer system with a processor, storage, network connectivity and a display. The client device usually executes a client application, maybe a browser that can communicate across a network with a server device and retrieve content. The retrieved content is shown on the client display. The browser can also execute program code such as JavaScript, Java, [etc.]. Client applications like the browser makes use of the clock signals generated on the client device to enable timer services allowing program code to be executed at regular intervals.
[0025] As used herein, the phrase “server device” may be used to refer to a device that executes a server application waiting to respond to a client request. The phrase “server device” has been broadly used to refer to server applications executing on the server device. On a client request such as a request from a browser, the server application sends back content that can be shown on the browser. The content can be text, graphics, sound, media streams, etc. A server device might execute a plurality of server applications, and in an embodiment a server application might itself act as a client and make requests to other server applications executing on the server device or other server devices on the network. A server device usually handles concurrent requests from a plurality of client devices. In an embodiment a plurality of server devices may appear as one to a plurality of client devices to handle the incoming client requests and to scale in performance.
[0026] As used herein, the term “control management unit” refers to the management computer system MCS 130 that manages and schedules activity on the UxV server devices and UxV client devices. MCS may employ complex server devices 151 , 152 , 154 , 155 and client devices itself with multiple displays to manage the complex network and communications 120 , 121 with multiple UXV server devices 152 , 153 and UXV client devices 101 , 102 , 103 . The flight path, maneuvers', navigation, formation, units, content type, content application types, etc. are input to MCS so that it can issue the appropriate control sequences to UXV server and client devices. Once the go is issued for a formation, the MCS also manages the system as a whole coordinating with the UXV server and client devices as needed. The MCS may also take the roles of master or a slave node network configuration in a MCS cluster to control the UXV server and client devices.
[0027] As used herein, the term UXV server device 152 , 153 is similar to a server device but maybe a customized application related to operating and controlling UXVs.
[0028] As used herein, the term UXV client device 101 , 102 , 103 is similar to a client device but maybe a customized application related to controlling and operating UXVs. The UXV client device may run client applications to control piloting, maneuvering, navigation, swarm capability, payload operation, etc. It can communicate with the UXV server device and MCS exchanging application objects and program code. It may have a display and a plurality of target areas.
[0029] In an embodiment the UXV client device can be composed of many target areas each separate but grouped together and brought into position as needed. The group of target areas though separate from each other serve to illustrate the content as a whole.
[0030] As used herein, the term “flight path” refers to the aerial flight path of a UXV. It may also mean the navigational path for a land based UV It is a pre-planned corridor which an UXV has to follow and be within.
[0031] As used herein, the term “navigation” refers to the instrumentation and computer systems used to guide a UXV on a flight path, making use of gps and other navigational signals to control the flight path of the UXV to get a particular destination or swarm capability. The UXV client device may be integrated with this capability and receive control signals from the UXV server device and MCS to manage this.
[0032] As used herein, the term “formation” is used to refer to the swarm capability of the UXVs to take up a particular configuration as desired by the MCS.
[0033] As used herein, the term “maneuvers” refers to the ability of UXV to navigate itself with control signals from the MCS or using program code and application objects in its computer system to take a flight path, navigate, take up a formation, etc. The UXV client device on the UXV maybe integrated to control this functionality communicating with the MCS as needed.
[0034] As used herein, the phrase “target area” will be used to refer to an area on the display device that can be used to show different content types. Content types can be text, graphics, media streams, and sound. The target area is a matrix of pixels that are turned on/off to show content types. Target areas can be grouped together and the content split among these target areas in chunks so that as a whole they form a single display of content.
[0035] As used herein, the phrase “target application area” will be used to refer to an area controlled by the target area on the client device to input/output content application types. The target area pixels are used to control the target application area which again is looked at as a matrix of pixels that can be turned on/off to input/output the content application types. Target application areas can be grouped together and the content split among these target application areas in chunks so that as a whole they form a single application area.
[0036] As used herein, the phrase “target area type” refers to the type of a target area on the client device. The target area type can be a type that shows dynamic content with motion or still content with sound, sensory, etc.
[0037] As used herein, the phrase “target application area type” refers to the type of a target application area controlled by the target area on the client device. The target application area type can be a type that is used for applications like paint, spray, sensory input, sensory output, block retrieve/drop, etc.
[0038] As used herein, the phrase “layout” refers to the type of a target area layout on the client device. The layout can be horizontal, vertical, line or any in an embodiment. The layout describes the way how target area object attributes are rendered in the target application area.
[0039] As used herein, the phrase “content type” refers to the type of content to be shown in the target area. The content can text, text-image, image, video or any in an embodiment. In another embodiments, the target area container can be linked to or a sensory output device enabling sensory content to be displayed. Sensory content can be text, graphics, sound mixed with signals to control changing the intensity of vibrations, color, smell/aroma, touch, feel, thermal, location, movement, etc.
[0040] As used herein, the phrase “content application type” refers to the type of content to be applied in the target application area. The content can be paint, spray, sensory input/output, block drop/retrieve, etc. In an embodiment the sensory input/output can be vision, sound, intensity, color, smell/aroma, touch, feel, thermal, location, movement, etc.
[0041] As used herein, the phrase “units or UXV units” refers to the number of UXV units in a swarm and maybe as low as 1.
[0042] As used herein, the phrase machine learning server 155 will be used to refer to an Artificial Intelligence server that can learn from previous experience without programming allowing input to be analyzed and provide feedback for more accurate processing.
[0043] As used herein, sensory server 154 is used to refer to sensor server that can process information from different type of sensors that maybe electro magnetic. It maybe as simple as measuring temperature or thickness or color to as complex as the radar light sensing signals.
[0044] As used herein, the phrase “application object” refers to a data object with attributes. The attributes include a target area, keywords, content type, program code, etc.
[0045] As used herein, the phrase “feedback input/output” is feedback received from or sent to the sensory devices in the target application area.
[0046] As used herein, the phrase “context” refers to the context of the application
[0047] As used herein, the phrase gps refers to Global Positioning System a satellite based navigation system in all weather conditions anywhere on or near earth when there is unobstructed view to at least 4 of these satellites. It is freely available to anyone with a gps receiver. cm gps or RTK gps is a newer version of the gps technology which again uses the satellites to provide cm positional accuracy. LIDAR (Light Detection and Ranging) is another form of remote sensing and surveying using laser and can be used for positional navigation. The term gps is used through the specification to refer to positional navigation using a form of gps like RTK or LIDAR or other forms of electro magnetic sensing.
[0048] As used herein, the phrase UXV 140 , 141 , 142 refers to unmanned aerial vehicles. It has also been loosely applied and also refers to unmanned ground vehicles and hybrid vehicles ie. vehicles that can fly as well go on the ground. UXVs use gps 110 , 111 , 112 to get to a particular geo location. The UXVs carry a payload. UXVs may also be fitted with client devices 101 , 102 , 103 that can integrate with the UXVs piloting and payload mechanism.
[0049] As used herein, the phrase positional signaling refers to the use of electro magnetic signals between client devices to maintain a fixed and cooperative position between each other. Positional signaling helps UXVs maintain formation, navigate and maneuver as needed. The signaling needs to be extremely fast with the clocks on the all the client devices synchronized with an atomic clock.
[0050] As used herein, the phrase payload refers to the load carried by a UXV. It can be as simple as a camera to as sophisticated as a robot with arms integrated into the UXV. The payload mechanism is usually controlled with help of a control unit which in an embodiment maybe the UXV client device.
[0051] As used herein, the phrase “swarm” 140 , 141 , 142 refers to a plurality of UXVs taking up a particular formation on command from the MCS. The client devices on the UXVs receive the control communication comprised of geo location coordinates and use their gps to get into position. Once they are in position they communicate among themselves by sensing the position of each other through positional signaling. They use positional signaling and the gps to continuously maintain the formation and maneuver as desired by the MCS. A swarm in an embodiment maybe comprised of just a single UXV.
[0052] As used herein, the phrase “program code” will be used to refer to code executed in a computer based system. Program code can be in interpreted form or compiled form. In interpreted form the code is at a high level in the form of a programming language and is interpreted one line at a time to execute the code. In compiled form, the program code is analyzed and compiled into a binary form that the computer system can understand and execute as instructions. The operating system of the computer system is usually in compiled form and enables executing applications, tasks, communicate across a network, with input and output devices, [etc.]. Applications can also interpret program code or compile such code to offer more services. A browser is one such application that allows content to be retrieved from a server device. The content is usually HTML. The browser usually executes a JavaScript interpreter so HTML which is a tag language can be associated with dynamic actions. JavaScript is an object oriented language, allowing HTML to be rendered, managed and manipulated on the display device. JavaScript also enables input, output and communication with a server device. A <script> tag usually identifies program code to be executed. The src attribute of the <script> tag is a link and can point to a file containing program code to be executed. The browser while parsing HTML content on recognizing a <script> tag loads the program code from the server device and executes the code using the JavaScript interpreter. The code on execution can create new HTML tags, JavaScript objects, render content, sign up with the timer service, [etc.].
[0053] As used herein, the phrase “data object” refers to an object with attributes and methods. Attribute is a specification that defines a property and is usually in the form of a name and value pair. Attributes usually have a type and rules for using the type. A type might be integer, long, character or String, Object, [etc.]. An object of a type integer may allow numbers from 0 to 2̂31−1 to be stored and operated upon. An integer object might be unsigned or signed allowing negative numbers. A character object might store values between 0 and 2̂16−1. A String object might be made up of multiple character objects in sequence. An object method is like a function call but with a namespace and visibility of just the object. Object methods enable manipulating the attributes of the object, like setting or retrieving the attribute value, [etc.] Objects can be extended or aggregated to form higher level types allowing complex structures to be represented and operated upon as objects. An Address object might have attributes, street, description, city, zipcode, state, and country where street might be a String object, description again might be a String object, city might be a String object, zipcode might be a Zipcode object., state might be State object and country might be a Country object. An Address object is an aggregation of multiple objects, while a Zipcode might be an extension of the String object with addition of another String object. The first String object in a Zipcode maybe named zip, while the second String object maybe named geography. The two attributes allow a Zipcode of the form postcode-geography. Methods of the form get Zip, and storeZip enables retrieving and storing zipcodes.
[0054] As used herein, the term “browser” may be used to refer to a client application that usually executes on a client device. A web browser is usually referred to as a browser application that is used to browse content on the internet/intranet from a server device. The content usually is tag language based such as HTML but can be others such as XML, XHTML, etc. The browser usually has the capability to show other content. HTML is a tag based language and uses tags to identify content. An HTML document is organized into sections with a “<begin> and “<end>” tag. It begins with a <HTML> tag followed by a <HEAD> tag (section), followed by a <BODY> tag (section). A body tag acts as a container for other tags like <TABLE>, <DIV>, <SPAN>, <P>, <FONT>, [etc.]. The browser renders HTML content onto the display device making use of any Cascading Style Sheets (CSS) usually in the HEAD section to format and style the content rendered. HTML enables a viewer to enjoy print quality visuals on the display. HTML can be associated with program code to create rich action oriented applications. A browser usually includes a program code interpreter or provides such a functionality to execute the program code associated with HTML. A browser also makes use of the timer functionality on a client device enabling program code to be executed at timer intervals. Program code sign up for these timer services using convenience function calls, such as settimer(function, delay), setinterval(function,delay) and clearinterval(id).
[0055] As used herein, the term “display” may be used to refer to the display device connected to the client device that allows content to be shown. Display is a piece of electrical equipment usually connected to the video source of the client device. The display can show text, graphics, generate sound, and maybe linked to/show sensory outputs, [etc.]. Display devices usually are (Liquid Crystal Display) LCD based but can be (Cathode Ray Tube) CRT, Plasma or Light Emitting Diode based, [etc.]. Display devices can be part of the client device as in a laptop/tablet/smart phone or separated from the client device as in a general purpose computer.
[0056] As used herein, the phrase “clock signal” may be used to refer to a timing means that generates a clock signal periodically on the client device. The client device usually offers a low level Application Programmable Interface (API) enabling an operating system or client device applications to make use of these signals to offer timer services, scheduling, [etc.] Timer services enable program code like shell scripts, application binary code, or at a higher level, an application like a browser with a program code interpreter to offer operating system type of timer services.
[0057] As used herein, the phrase “click” refers to a click or change in state of an input device such as a mouse or a joystick button, etc. in a computer based system.
[0058] As used herein, the phrase “link” refers to an URL. URLs are Uniform Resource Locators and are of the form http://login:password@address/context?querystring. Address can be a numeric such as an IP address or a hostname.domainname.com. query string can be of the form “parameter=value”.
[0059] As used herein, the phrase “query-terms” refers to parameters passed from the client device to the server device as part of a request for an application status/update, etc. Query terms can be keywords or terms of a search such as city, state, country, gps location, [etc.] The query term enables the server device to match the query-term to an attribute target terms, [etc.] in the data objects on the server device and select matching data objects to send back to the client device.
[0060] As used herein, the phrase “target-terms” refers to an attribute in the data object allowing the query-terms parameter sent by the client-device to be matched. The server device on receiving a request, uses an index to find matching application object keys. In an embodiment the index might be constructed by feeding the application objects to an index writer. The index writer breaks down the object attributes such as name, description, target terms into words and adds them to index. The index might be of type inverted index. To match using the index, the server device might use an index searcher that goes through the said index and finds all the documents with words that match the said terms. The matching documents could then be used to retrieve keys to the advertisement objects. The matching objects are then returned by the server and can be included in a response.
[0061] As used herein, the terms “Ajax”, “XmlHttpRequest” refers to the ability of the client application like a browser executing on a client device to communicate with the server device to retrieve content asynchronously. The XmlHttpRequest can be initiated on a clock signal or a count threshold trigger or a click to retrieve content from the server device; said content can be selectively refreshed onto the display device using a tag like <DIV>. Before the availability of XmlHttpRequest, a request by a browser would stop and pause functions until the request was completed. The returned content was updated as a complete HTML page and caused a flicker as well as long waits. XmlHttpRequest and selective refresh of the client display enables rich application experience with just HTML and JavaScript.
[0062] As used herein, the terms “xsocket-http”, “reverse Ajax”, “Server push” refers to the ability of the server device to push content asynchronously to a client device. The server device starts the content push based on an initial request for content from the client device and pushes the content on changes or events on the server devices or client devices. Such events on the server side might be timing means like clock signal timers, or a change of state communication from a client device such as a click or input means. Server push eliminates the need for polling the server device for content by the client device using a clock signal. Polling can be expensive in terms of resources used, while asynchronous server push eliminates the cost of these expensive resources.
[0063] As used herein, the terms “websockets”, refers to the ability to communicate between a client and server device in full duplex using TCP communications protocol. Websockets enables port 80 , port usually used for browser-server communications and through firewalls to use the http protocol for TCP communications. The TCP communications is layered on top of http protocol with some extra overhead. This is a very useful protocol but is usually not enabled in browsers due to security limitations.
[0064] As used herein, the phrase “website” refers to a server device and a server application 160 on the server device that is able to respond back with content, usually HTML based, but could offer other services like email, cloud computing, ftp, [etc.]. A website usually has a name or an IP address. If it has a name it is registered with a name registry so that it can be discovered by users on the internet. The name is usually of the form http/www.name.XXX., where XXX is a Top Level Domain Name (TLD).
[0065] As used herein, the phrase “Object converter” refers to a object converter that allows objects with attributes to be represented as Extended Markup Language (XML) or in JavaScript Object Notation (JSON). XML is a tag language that can be used to describe objects with attributes, schemas, [etc.]. HTML tag language is nothing else but XML and is used to describe content to be shown on a display device. XML can be used to describe a Java or a JavaScript language object. The advantage of using XML to describe a language object is it makes the object portable across operating systems, computer systems, and also allows objects to be sent across networks. JSON is another way of representing objects and represents object attributes as name, value pairs. Object converter provides methods that allow a language object to be converted to XML/JSON, and from JSON/XML back to the language objects.
[0066] As used herein, the phrase “client sensory input feedback” refers to an input sent from a client device to a server device. The sensory input can be graphics, haptic, motion, magnetic, location, etc.
[0067] System
[0068] Referring first to an UXV control system FIG. 1 according to embodiments of the present invention is shown. As shown in, the control system includes a control management unit MCS 130 , a plurality of UXV client devices ( 101 , 102 , 103 ), a plurality of UXV server devices 152 , 153 , an operator 131 , a swarm of UXVs 140 , 141 , 142 . MCS manages the control system and provides a visual display of the system. MCS manages the plurality of UXV server devices that in turn communicate and manage the plurality of UXV client devices which in turn manage a plurality of target areas which in turn manage the target application areas. The MCS also directly communicates with the UXV client devices for feedback, etc. The plurality of UXV client devices communicate directly among themselves as well as communicating with the server devices 120 , 121 . The UXV client device is located on a UXV and may also be hooked up to the UXV control unit, controlling the piloting and functions of the UXV. The target area is located on the client device and in turn controls the target application area and content application type. Input is first rendered in the target area triggering mapping of the target area to the target application area using the associated content application type.
[0069] In an embodiment, the target application area maybe lane marking with the associated content type, paint. A 3D geographical mapping/model 150 of the road and the lane to be marked is input to the MCS. The MCS goes through the mapping/model and generates commands to the server unit to dispatch a plurality of UXVs with payload of paint as needed to reach the configured swarm capability and as needed for optimum work. The UXV server device generates the flight path, gps geo location map as needed and communicates these in the form of application objects to the UXV client devices in the selected swarm. The UXV client devices programs the autopilot on the UXVs with the flight path, navigates and maneuvers' the UXVs as needed to get to the geo location specified. Once the geo location is reached, client applications receive application objects as input from the server devices, activate the target areas to receive input from the target application area which maybe vision or sensory related and may process the input on the client device or send as feedback to the server device for further processing. The client application then renders the model on the target device activating the drivers controlling the target application area to apply the control application type mapping the contents of the target area, enabling paint to be marked on the road.
[0070] Lane marking is composed of a long strip of paint that maybe miles long and continuous or broken. To speed up marking a long strip, the server device may enable a swarm of UXVs breaking the long strip into chunks with each UXV handling a chunk of this space. The client devices communicate among themselves using positional signaling to aid handling chunking and to keep formation as they apply the content application type all over as in the target area that maybe a section as in the model.
[0071] FIG. 2 shows a flow of the steps to paint in an embodiment. 201 shows a 3D model input to MCS by uploading the contents. The model comprises the lane segments and positions to be marked. MCS server devices 202 analyze the model data and based on input provided in the model determine the number of UXVs needed for the job. The input may manually override the automation to request a single UXV, etc. 203 . The server applications determine the flight path, maneuver, positional signaling, navigation, number of UXVs needed for the job 204 . Once processing is complete, the job is communicated to MCS for dispatch 205 . MCS communicates the flight plan, job, etc. to the client devices and dispatches the UXVs 206 . UXVs on the job command take flight 207 and the client device application auto pilot the UXV to navigate using GPS and positional navigation to reach the target area 208 . On reaching target area, the client device issues appropriate commands to hover and land on target area 209 . The client device next initiates the job which maybe stripping paint or new paint to be marked 210 . The client device next uses its sensors and vision to accurately position itself 211 . The vision and sensory information is sent across to MCS for processing using 154 the sensor server and 155 machine learning server for feedback to position and start job. The input sent by MCS is next mapped to the target area 212 . The target area contents are communicated back to MCS for virtual viewing of target area on the MCS console, etc. 213 . The target area is next mapped to the target application area 214 activating appropriate controls to activate the target application area type that activate/apply the desired content type 215 . In an embodiment the target application area type maybe paint 216 which activates the paint spray gun, positioning the nozzle based on the mapping in the target area mapped to the target application area. Mapping to the target application area activates the target application type which maybe the paint spray nozzle gun which will activate the content type paint. A pixel or a range of pixels can be sprayed with paint the target application content type as mapped in the target application area. Once painted the sensory signals and vision is communicated to 154 and 155 for feedback input. In another embodiment the target application area maybe stripping which activates the strip gun, positioning the nozzle based on the mapping in the target area and the content type would be to strip paint on the road 217 . The client device adjusts the position of the nozzle and the UXV to account for the pixel or range of pixels painted 218 , while monitoring pixels done and payload capacity 219 and communicating job parameters back to MCS for feedback 220 . MCS determines if job is done and creates flight plan to navigate back to home 221 and issues appropriate commands to client device to head back home 222 .
[0072] In another embodiment, for vertical applications like painting a large sky scraper, the model of the building is again input to the MCS which sends the control signals to the server devices to activate a swarm of UXVs as needed to get into position. Once the geo location is reached, the client device again communicates with the server device sending back vision/sensory inputs while receiving application objects for processing, activating the target areas and the target application areas so that the appropriate driver is enabled to apply the content application type. The client devices again maintain swarm positions using positional signaling while applying the content application type.
[0073] Another embodiment would be crop inspection for diseases or damages, etc. The model of the field is input to the MCS which sends control signals to the UXV server devices to enable a swarm of UXVs that on reaching the desired geo location activate the target areas to send back vision and sensory inputs from the target application areas. The client or the server device on further processing may activate more finer sensory inputs ( 154 ) and capture the inputs for further processing. If processing reveals a problem in an embodiment, if inspection and spraying components are part of the payload, the client application may activate a spraying application that will render how the spray has to be applied in the target area activating the target application area to apply the appropriate content application type.
[0074] In another embodiment instead of inspection, only the spraying component maybe involved so as to use a swarm of UXVs to apply the appropriate content application type as needed only to the parts that need to be sprayed saving on costs, speeding up the spraying process, etc.
[0075] In another embodiment, the payload maybe blocks of pre-fabricated components which may need to be dropped into position on top of one another and aligned, etc. Again based on the model the MCS sends across the control commands to the UXV server devices which activates a swarm of UXVs to get into position and use the target areas to collect input about the layout for processing while dropping blocks as needed in pre-determined locations, aligning said block, etc. as a content application type.
[0076] While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.
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Horizontal applications and vertical application like lane marking and painting sky scrapers are very time consuming and slow today while inspection of crops is still manual and expensive and hard due to labor problems, etc. This invention describes using a swarm of UXVs to disrupt this space by increasing the speed by 10× to 50× or more saving time, labor and costs increasing productivity.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to inkless fingerprinting systems used for identification purposes and to unique solvents, color-formers, and developer combinations for such systems.
2. Background of the Art
The fingerprint patterns or ridge endings and ridge separations are highly individualized and are not altered with time. The unique character of the fingerprint of an individual has provided the basis for police identification of criminals, establishing the identity of accident victims, newly born babies, and numerous other situations and the comparison of fingerprint patterns has long been accepted as an absolute means of identifying individuals in a multitude of criminal and non-criminal situations.
Traditionally fingerprints have been made with printing or writing types of ink, usually comprising finely ground carbon black particles dispersed in a liquid vehicle. The most common method used to make fingerprints is to impregnate a pad with ink, transfer the ink to the surface of the object to be fingerprinted or identified, and subsequently transfer the ink to the surface of the substrate where the final print is to be made. Such a procedure is cumbersome, time consuming, and results in severe soiling of the hands and clothing of everyone involved in the fingerprinting process. This method also suffers from other drawbacks. If the fingers are wet with perspiration the image tends to blur and to lose resolution. This technique also requires great care and expertise to obtain good print.
In order for a fingerprint identification system to be commercially acceptable it must be extremely stable and reliable. The prints must be distinct and clear and must be easily readable by the human eye and by automated fingerprint reading systems which are finding increased use especially within law enforcement agencies. Furthermore the prints must form very rapidly and must possess a high degree of stability toward temperature, humidity, and light. The systems must be simple and aesthetically inoffensive. Inking methods suffer from the need to clean the finger of residual ink to prevent staining of objects handled after the fingerprint has been taken. This creates a disposal problem of the wipes used to clean the ink from the fingers. The cleaning operation is particularly objectionable when fingerprinting or footprinting babies.
Although improved techniques for fingerprinting which do not stain the finger have been developed they have not been widely adopted.
Draeger et al., U.S. Pat. No. 5,143,551 discloses a single use inking card for fingerprinting, with overlapping interconnected front and back sheets with an inked sheet in between.
Koch, U.S. Pat. No. 5,263,742 discloses an inkless fingerprinting system comprising a transparent sheet coated with a pressure sensitive adhesive film and an element for back-reflecting radiant energy for making a copy of the fingerprint.
Lougheed et al., U.S. Pat. No. 5,233,404 also discloses an inkless method of recording a fingerprint. A finger is placed on an illuminated surface and the image is projected onto a viewing surface. The image is then recorded with a charge coupled device which is rolled synchronously with the finger on the illuminated surface.
In yet another system for recording fingerprints, U.S. Pat. No. 4,699,077 teaches a pad impregnated with a color-former composition sealed in a packet and associated with a substrate carrying developer composition. The pad contains a polyhydroxy aromatic developer and the receptor contains the color-former. Exposure of sensitive skin to the these polyhydroxy aromatics is subject to question because of the nature of these compounds.
A fingerprint system based upon the formation of a colored image by the reaction of a transition metal salt with a dithiooxamide ligand is commercially available from 3M Company, St. Paul, Minn. under the name of "The Identifier." However, the color of the image produced is not black.
Additional inkless fingerprinting systems have been proposed. U.S. Pat. No. 3,831,552 discloses the use of magnetizable powders. U.S. Pat. No. 2,082,735 discloses the use of chelation of metal salts with organic acids. U.S. Pat. Nos. 3,960,632, 4,262,623, and 4,379,178 disclose the reaction of 8-hydroxyquinoline with metal salts such as ferric chloride. U.S. Pat. No. 4,232,083 discloses the use of metal complexing compounds having a plurality of ligand groups with transition metal salts of oleophilic organic acids to form dark images which can be useful in fingerprinting systems.
Vassiliades, U.S. Pat. No. 5,009,919 discloses a system for inkless fingerprinting using a color-former in an oleophilic solvent and a substrate coated on one surface with color developer. Vasiliades lists requirements for the solvent, specifically mentioning solvating properties for the color-former, low evaporation rate, good flow properties, and no adverse-toxicological effects. He then lists solvents such as alkylated phenyls, such as monoisobutyl biphenyl and monoisopropyl biphenyl; chlorinated paraffins; alkylated naphthalenes; partially hydrogenated terphenyls, such as Monsanto HB-40; natural vegetable oils such as soya-bean oil, cottonseed oil, and coconut oil; ester alcohols such as Eastman Kodak's Texanol™; alkylated glycol ethers and ether acetates such as Eastman Kodak's Ektasolve™ series; and combinations thereof. Numerous developers for the color-former are described including common carbonless paper developers such as acid clays, phenolics, and salicylic acid; as well as color-formers obtained by augmenting the developer with additional metal developers. A variation on this method is also taught by Vassiliades in U.S. Pat. No. 4,879,134 wherein a fingerprint pad contains reacted color-former and developer. Here again, solvents, color-formers, and developers are those described in U.S. Pat. No. 5,009,919 above.
While these patents recognize the need for fast development of a fingerprint system that does not stain fingers, they use only the usual carbonless paper solvents. These solvents all suffer from specific deficiencies, such as objectionable odor, limited solubility of the leuco dye color-former (as in the case of the vegetable oils), toxicity (as in the case of the chlorinated paraffins), or irritation of the skin (as in the instances involving aromatic and hydrogenated aromatics).
One aspect of the importance of the solvent to image-forming properties, such as high solubility of the color-former, is the need for maintaining compatibility with sensitive skin. This issue was addressed in Hilterhaus et al., U.S. Pat. 4,859,650. Hilterhaus et al. were concerned with the preparation of a carbonless paper using leuco dye color-formers in capsules. The inventors used triphenylmethane leuco dyes with improved solubility. This allowed them to use a solvent composed of at least 80% of plant, animal, or paraffin oils. Their improved leuco dyes were soluble to the extent of 7 to 10 parts by weight in their preferred solvents compared with a solubility of only 1 part by weight of a typical commercially available color-former in their preferred solvents. The inventors were motivated because: "The mentioned solvents for carbonless paper are occasionally viewed with distrust, causing skin irritations upon use of the carbon paper [sic]manufactured therewith." (column 1, lines 24-27) and "Accordingly, there is a need to be able to substitute these solvents by such solvents which are less hazardous in this connection." (column 1, lines 31-33).
Of critical importance to the fingerprinting system is the solvent. The solvent for the color-former must satisfy many requirements. It must be nontoxic and not have an unpleasant odor. It must be colorless or nearly colorless. It must be able to dissolve the color-former and provide a medium in which rapid reaction between color-former and developer can occur. It must be stable and not react with either the color-former or developer. It should be absorbed into the substrate without causing blotting or "feathering." Solvents that have traditionally been used for fingerprinting include diarylalkanes, such as phenylxylylethane and phenylethylphenylethane; aromatic hydrocarbons such as alkylnaphthalenes; biphenyls and substituted biphenyls.
A major problem with present inkless fingerprinting systems is the slow rate of development of the image (i.e., slow speed). This is because inkless fingerprinting systems have traditionally been based on carbonless paper chemistry, and employed color-formers, solvents, and developers designed for carbonless papers. However, unlike carbonless paper systems where initial development is important but ultimate image density develops only after several hours; a fingerprinting system requires rapid development of a good, dark fingerprint within seconds. This is to allow examination of the fingerprint and re-fingerprinting if necessary. Quite often with previous inkless fingerprinting systems, the color of the fingerprint did not appear to develop so the finger was again placed on the developer. Later examination indicated overlapping fingerprints. This, of course, is unacceptable. Similarly, the use of encapsulation solvents for carbonless paper is not favored as carbonless paper solvents do not necessarily satisfy the requirements for a good fingerprinting solvent. Some irritate the skin. Some are expensive, some do not dissolve enough color-former to provide an intense color, and some are too volatile. A particular shortcoming of encapsulation solvents for carbonless paper is that they are "too slow." That is, when used in fingerprinting the image forms very slowly. The need for an improved inkless fingerprinting system remains.
SUMMARY OF THE INVENTION
The present invention describes a fingerprinting system comprising means capable of releasably retaining a liquid and a liquid composition releasably retained in said means, said liquid composition comprising a leuco color-former compound, a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms, a substrate for receiving fingerprints associated therewith, the substrate being coated on at least a portion of one surface thereof with a color developing substance comprising a phenol/aldehyde condensation product produced by the reaction together of an alkyl-substituted salicylic acid, an alkyl-substituted phenol, and an aldehyde, the condensation product having been reacted with a metal source.
In another embodiment the liquid composition may further comprise a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms. In another embodiment the liquid composition may further comprise a mixture of a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms and an alkyl benzoate wherein the alkyl group contains 10-18 carbon atoms.
The fingerprint system of the present invention can be prepared by combining specific solvents satisfying the above requirements with specific color-formers and developers. The present invention provides a fingerprint system which can solve the problems of conventional inkless fingerprinting systems and which is inexpensive, provides excellent development speed, and forms sharp images with dark, permanent color.
In one embodiment, the color-former is a fluoran leuco dye susbstituted in the 2-position with anilino groups. In a preferred embodiment, the leuco dye color-former is a mixture of 2-anilino-3-methyl-6-diethylaminofluoran and 2-anilino-3-methyl-6-dibutylaminofluoran. Preferrably, the leuco dye color-former is present in the fingerprinting system in an amount of from 8-14 weight percent, based upon the total weight of said fingerprinting system.
In a preferred embodiment, the alkyl phthalate is diethyl phthalate and the alkyl group of the alkyl benzoate contains 12-15 carbon atoms. In one embodiment the weight ratio of dialkyl phthalate/alkyl benzoate is in the range of from 3:1 to 1:3.
The formation of the image is rapid and the resolution of the image is sharp and clear. The image is also stable for long periods of time. The solvents used to dissolve the color-former are not only compatible with the skin, but they are able to dissolve high concentrations of color-former enabling the formation of a dark image in very short times. The invention overcomes the problems associated the previous art and permits the use of an innocuous non staining finger print ink useful in commercial trade.
The invention further comprises a method of generating an image of the fingerprint by transfer of leuco dye color-former dissolved in an innocuous solvent combination.
As used herein, the term "fingerprint," also encompasses "footprint" such as those taken of newly born babies and placed on birth records, and "noseprint" such as those taken of animals.
As used herein, the term "inkless" means the absence of colored pigments such as carbon black and as being distinct from printing inks.
As is well understood in this technical area, a large degree of substitution is not only tolerated, but is often advisable. As a means of simplifying the discussion and recitation of certain terminology used throughout this application, the terms "group" and "moiety" are used to differentiate between chemical species that allow for substitution or which may be substituted and those which do not so allow or may not be so substituted. Thus, when the term "group" is used to describe a chemical substituent, the described chemical material includes the unsubstituted group and that group with conventional substitution. Where the term "moiety" is used to describe a chemical compound or substituent, only an unsubstituted chemical material is intended to be included. For example, the phrase "alkyl group" is intended to include not only pure open-chain and cyclic saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl, cyclohexyl, adamantyl, octadecyl, and the like, but also alkyl substituents bearing further substituents known in the art, such as hydroxyl, alkoxy, vinyl, phenyl, halogen atoms (F, Cl, Br, and I), cyano, nitro, amino, carboxyl, etc. On the other hand, the phrase "alkyl moiety" is limited to the inclusion of only pure open-chain and cyclic saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl, cyclohexyl, adamantyl, octadecyl, and the like.
Other aspects, advantages, and benefits of the present invention are apparent from the detailed description, examples, and claims.
DETAILED DESCRIPTION OF THE INVENTION
This invention describes an improved system for fingerprinting. The essential components of a fingerprinting system are the leuco dye color-former compounds, the solvent for the color-former compounds, and the developer. In order for a fingerprinting system to function properly, all components must work well together. For example, a high concentration of color-former is important because formation of a dark image is required. Also, the solvent must wet the finger evenly, distributing the solvent/color-former mixture on the finger. The solvent must also wet the paper evenly so as not to form a blurred or smeared fingerprint.
The color-former compounds are leuco dye color-formers which posses the unique property of being colorless in neutral or alkaline media, but become colored when they react with an acidic or electron accepting substance.
The color-former selected in the subject invention must be able to provide a black image and must also possess the property of being soluble in the solvents of choice at high levels. Preferrably, the leuco dye color-former is present in the fingerprinting system in an amount of from 8-14 weight percent, based upon the total weight of the solvent plus color-formers in said fingerprinting system.
In one embodiment, the color-former is a fluoran leuco dye color-former susbstituted in the 2-position with an anilino group. In a preferred embodiment, the leuco dye color-former is a mixture of 2-anilino-3-methyl-6-diethylaminofluoran and 2-anilino-3-methyl-6-dibutylaminofluoran. These color-formers are available from the Ciba Geigy Company under the tradenames of Black I-R and Black I-2R.
The solvents for the fingerprinting system must also posses unique properties. As noted above, the solvent for the color-former must satisfy many requirements. It must be nontoxic, odorless, colorless, nonreactive, and non wicking. It must also be able to dissolve the color-former and provide a medium in which rapid reaction between color-former and developer can occur.
In one embodiment, the solvent is a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms. In another embodiment the solvent is a mixture of a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms and an alkyl benzoate wherein the alkyl group contains 10-18 carbon atoms. In a further embodiment, the solvent is a mixture of a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms and an alkyl ester of a fatty acid wherein the alkyl group contains 1-5 carbon atoms and the fatty acid group contains 10 to 18 carbon atoms. In a preferred embodiment, the dialkyl phthalate is diethyl phthalate and the alkyl group of the alkyl benzoate contains 12-15 carbon atoms. Preferrably, the weight ratio of dialkyl phthalate to alkyl benzoate is in the range of from 3:1 to 1:3. In another preferred embodiment, the dialkyl phthalate is diethyl phthalate and the alkyl ester is isopropyl palmitate or isopropyl myristate. Preferrably, the weight ratio of dialkyl phthalate to alkyl ester is in the range of from 3:1 to 1:3.
The preferred solvents meet the above noted requirements. They have a high solubility for common leuco dye color-formers, give rapid development of dark images when used with a commercially available developer composed of a metal salt of a salicylic acid terminated oligomer of phenol with formaldehyde. They are also non irritating to the skin. A preferred co-solvent, Finsolve™ is readily available and is used in the cosmetic industry.
In the present invention it was found the usual carbonless paper developers did not provide the rapid development speeds needed for this immediate development of the fingerprint.
The developers used in the present invention are produced by the interaction of an alkyl-substituted salicylic acid, an alkyl-substituted phenol, an aldehyde, and a metal source to form a phenol/aldehyde condensation product.
The alkyl-substituted salicylic acid is preferably substituted with at least one alkyl group containing three or more carbon atoms. Preferably, the alkyl group contains at least four carbon atoms, especially four to twelve carbon atoms. Particularly useful are salicylic acids of the formula: ##STR1## where R is an alkyl group containing form four to twelve carbon atoms. Preferably, the group R is octyl or nonyl, especially tertiary-octyl (derived from diisobutene) and nonyl (derived from propylene trimer). The group R may also be a dodecyl group. The most preferred materials use a nonyl group.
The alkylphenol component preferably contains at least one alkyl group containing at least three carbon atoms, especially four to twelve carbon atoms. In particular, the phenols are phenols substituted in the para-position with an alkyl group, R', containing four to twelve carbon atoms, particularly tertiary-butyl, tertiary-octyl, nonyl (derived from propylene trimer), and dodecyl. The preferred materials use a tertiary-octyl group.
The aldehyde is preferably formaldehyde, although the formaldehyde may be supplied, for example, from paraformaldehyde, or a similar source of formaldehyde.
The preferred metal source is zinc oxide.
The exact composition of the product is not known, but it is believed to have the general formula: ##STR2##
The phenol/aldehyde condensation product may be synthesized by combining and heating the alkyl-substituted salicylic acid, the alkyl-substituted phenol, the aldehyde, the metal source, and water.
A developer of this type, based upon a zinc salt of a salicylic acid terminated oligomer of phenol/formaldehyde is sold by the Schenectady Chemical Company under the name of HRJ 10802. Developers of this type are further described in U.S. Pat. No. 5,017,546 the disclosure of which is incorporated herein by reference.
The developer may be coated on the developer sheet by a variety of means such as wire wound rod, reverse roll coating, curtain coating, knife coating, etc. Good results can be obtained using a coating mixture containing approximately 20% developer to give a coating weight of about 1.8 pounds per ream (1300 square feet).
As mentioned above, when compared with carbonless paper, speed of image formation is of paramount importance in inkless fingerprinting. The present fingerprinting system provides a black image on a light background. Upon use, the fingerprint is immediately visible just a few seconds after the imprint is made.
The density of the image is a function of the solubility of the color former in the solvent. In general a solubility of less than 4-6% (wt %) will not give an image dark enough to be useful in a fingerprint system. Unfortunately, most color-formers are not soluble in solvents typically employed in carbonless paper at greater than this amount, or if soluble they slowly crystallize or precipitate from solution. We have found that a mixture of color-formers in favored solvents of the invention, do not interact and each color-former maintains its individual solubility. By using two black color-formers, each of which is soluble in a developer a very high concentration of color-former in the solvents of this invention can be obtained.
For example, diethyl phthalate, (DEP) a co-solvent commonly used carbonless tends to give a very slow image when used alone. Therefore, mixtures of DEP with other solvents are often used to encapsulate color-formers for carbonless papers. In contrast, diethyl phthalate works very well in the present fingerprinting system.
Objects and advantages of this invention will now be illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention.
EXAMPLES
All materials used in the following examples were readily available from standard commercial sources, such as Aldrich Chemical Co. (Milwaukee, Wis.), unless otherwise specified. All percentages are by weight unless otherwise indicated. The following additional terms and materials may be used.
Colloid 230 is a surfactant sold by Colloids, Inc., Newark N.J.
Clay #2 is sold by Thiele Kaolin Company, Sandersville Ga.
Calcined clay is available from J. M. Huber Co., Macon Ga.
Ciba Geigy Black I-R is 2-anilino-3-methyl-6-diethylamino fluoran and is available from Ciba Geigy, Greensboro, N.C. [CAS 29512-49-0].
Ciba Geigy Black I-2R is 2-anilino-3-methyl-6-dibutylamino fluoran and is available from Ciba Geigy, Greensboro, N.C. [CAS 89331-94-2].
DEP is diethyl phthalate CAS [84-66-2]
Dow 620 latex is available from Dow Chemical Co., Midland Mich.
EXX is Exxon AE 700 a mixture of C 7 -C 9 branched alkyl phthalate esters available from Exxon Corp.
Finsolve™ TN is a mixture of C 12 -C 15 alkyl benzoates sold by Finetex Corp., Elmwood Park, N.J. [CAS 684 11-27-8]. It has an acute oral toxicity of 34.5 g/kg and a primary dermal irritation index (rabbits) of 0.08.
Foam Kill is a silicone defoamer manufactured by Crucible Chemical Co., Greenville S.C.
HRJ 4023 is a zinc salt of a phenolic developer sold by Schenectedy Chemical Co., Schenectedy, N.Y.
HRJ 10802 is a zinc salt of a phenolic/salicylate developer sold by
Schenectedy Chemical Co., Schenectedy N.Y.
IPP is isopropyl palmitate CH 3 (CH 2 ) 14 COO--CH(CH 3 ) 2
IPM is isopropylmyristate CH 3 (CH 2 ) 12 COO--CH(CH 3 ) 2
PVA 603 is a polyvinyl alcohol sold by Air Products Company, Allentown Pa.
Starch #716 is available from Clinton Corp., Clinton Iowa.
Examples 1-2
Preparation of Color-Former Sheet:
A color-former solution was prepared by dissolving 6 parts by weight of Ciba Geigy Black I-R (2-anilino-3-methyl-6-diethylamino fluoran) and 6 parts by weight of Ciba Geigy Black I-2R (2-anilino-3-methyl-6-dibutylamino fluoran) in 88 parts by weight solvent. The solvent was a mixture of 33 parts by weight of Finsolve™ TN and 67 parts by weight of diethyl phthalate. Finsolve™ TN is a mixture of C 12-C 15 alkyl benzoates. It has an acute oral toxicity of 34.5 g/kg and a primary dermal irritation index (rabbits) of 0.08. Diethyl phthalate has an acute oral toxicity of 1.0 g/kg (rabbit). A 4 inch by 7 inch (10.16 cm×17.78 cm) piece of crepe paper was saturated with 0.50 mL of a solution of color-former. The paper was then sealed in a packet of impermeable paper coated with a heat sealable polymer. The color-former/solvent was allowed to equilibrate in the sealed packet overnight.
Example 1
A developer solution was prepared from the components shown below. A developer sheet was prepared by coating the developer solution on 20 pound basis weight paper was coated on a reverse roll coater. The dry coating weight was 1.4 lb/ream.
______________________________________Component Amount Weight (Dry)______________________________________Water 32.88 0.0Surfactant 0.63 0.274Clays 36.25 36.25Starch (32%) 9.38 3.00HRJ 10802 17.5 8.75Styrene/Butadiene latex 4.0 2.0______________________________________
The index finger of a person was pressed lightly on the pad of crepe paper saturated with the color-former solution described above. The finger was then pressed against the paper prepared with the coating containing the developer. A black image of the fingerprint of the finger appeared immediately. The finger was wiped clean with a tissue with no discomfort to the skin.
Example 2
A second solution of developer was made up and applied to 20 pound basis weight paper by silk screen printing on a small area of the paper. This developer solution contained the following components:
A silk screen master was prepared with a silk screen with #305 mesh. The developer solution was silk screen printed onto a small area of 20 pound basis weight paper. The dry coating weight was 2.0-2.2 lb/ream.
______________________________________Component Amount Weight (Dry)______________________________________Water 26.0 0.0Surfactant 0.60 0.261Clays 38.25 38.25Poly(vinyl alcohol) (40.0%) 8.25 3.3HRJ 10802 (50.0%) 19.25 9.625Styrene/Butadiene latex (50%) 4.4 2.2Silicone Defoamer (56.0%) 3.3 0.185______________________________________
The index finger of a person was pressed lightly on the sheet of crepe paper saturated with the color-former solution described above. The finger was then pressed against the paper in the area silk screen coated with developer. A black image of the fingerprint of the finger appeared immediately. The finger was wiped clean with a tissue with no discomfort to the skin.
Examples 3
Examples 3 describes the evaluation and comparison of additional solvents. Color-former and solvent were placed in a vial and the mixture heated to effect solution. The vial was closed and kept at room temperature for 3 days. If solid precipitated from the solution, the solvent was considered not acceptable. The solubilities of two leuco dye color-formers in various solvents is as follows.
______________________________________Color-Former Solvent Solubility (wt %)______________________________________Ciba Geigy I-R Finsolve ™ TN ca. 3-4%Ciba Geigy I-R IPP ca. 3-4%Ciba Geigy I-R IPM ca. 3-4%Ciba Geigy I-2R DEP ca. 6%Ciba Geigy I-2R Finsolve ™ TN ca. 3-4%Ciba Geigy I-2R IPP ca. 3-4%Ciba Geigy I-2R IPM ca. 8%______________________________________
Example 4
Color-former solutions were prepared by dissolving various amounts of Ciba Geigy Black I-R (2-anilino-3-methyl-6-diethylamino fluoran) and/or various amounts of of Ciba Geigy Black I-2R (2-anilino-3-methyl-6-dibutylamino fluoran) in various solvents or solvent mixtures. The solvents evaluated are shown in the table below. A 4 inch by 7 inch (10.16 cm×17.78 cm) piece of crepe paper was saturated with 0.50 mL of a solution of color-former. The paper was then heat sealed in a laminated aluminum foil packet. The color-former/solvent was allowed to equilibrate in the sealed packet overnight.
The packet was opened and the crepe paper was pressed several times on the index finger. The finger was then lightly placed on the a sheet of CF carbonless paper and the image was evaluated. Two sheets of CF carbonless papers were used to develop the image. The first sheeet was a developer sheet of 3M CF Schotchmark™ Carbonless Paper and was obtained from Carbonless Products Department, 3M Co, St. Paul, Minn. 3M CF Schotchmark™ Carbonless Paper is a very reactive developer for carbonless paper. It is believed to contain a zinc salt of a phenolic resin such as HRJ 4023. The second sheet was a developer sheet prepared as in Example 1 above and contained HRJ 10802, a zinc salt of a phenolic/salicylate developer.
The image was gaded as follows:
Good if a useable clear fingerprint resulted within 15 seconds.
Poor if a fingerprint developed in longer than 15 seconds, if the fingerprint was smudged, or illegible (i.e., if the fingerprint spread, bloomed, or wicked into the paper).
The table below, compares the speed of development of two developer systems using solutions containing the same color-formers. The Scotchmark™ system employs a developer on a zincated phenolic resin. The developer of the invention employs a zincated phenolic benzoate polymer. As shown in the following table, the ability to form an image rapidly is a function of the solvent or solvents, as well as the developer. When a zinc salt of a phenolic resin was used as a developer poor results were obtained. When a zinc salt of a phenolic/salicylate resin was used as a developer good results were obtained only when certain solvents were used.
__________________________________________________________________________ Fingerprint on Fingerprint onColor-Former Concentration Solvent Scotchmark ™ CF CF of Example 1__________________________________________________________________________3-4% Ciba Geigy Black I-R FIN poor poor3-4% Ciba Geigy Black I-R IPP poor poor3-4% Ciba Geigy Black I-R IPM poor poor 8% Ciba Geigy Black I-R DEP poor good12% Ciba Geigy Black I-R DEP poor good12%* Ciba Geigy Black I-R DEP/FIN (2:1) poor good12%* Ciba Geigy Black I-R DEP/IPP (2:1) poor good12%* Ciba Geigy Black I-R DEP/IPM (3:1) poor good12%* Ciba Geigy Black I-R EXX/FIN (1:1) poor poor15% Ciba Geigy Black I-R EXX poor poor3-4% Ciba Geigy Black I-2R FIN poor poor3-4% Ciba Geigy Black I-2R IPP poor poor 8% Ciba Geigy Black I-2R IPM poor poor12%* Ciba Geigy Black I-2R DEP/FIN (2:1) poor borderline12%* Ciba Geigy Black I-2R EXX/IPP (1:1) poor borderline15% Ciba Geigy Black I-2R EXX poor poor 6% Ciba Geigy Black I-R + DEP poor good 6% Ciba Geigy Black I-2R 6% Ciba Geigy Black I-R + DEP/FIN (1:1) poor good 6% Ciba Geigy Black I-2R 6% Ciba Geigy Black I-R + DEP/IPP (1:1) poor good 6% Ciba Geigy Black I-2R 6%* Ciba Geigy Black I-R + EXX/FIN (2:1) poor borderline 6% Ciba Geigy Black I-2R 6%* Ciba Geigy Black I-R + EXX/IPP (2:1) poor borderline 6% Ciba Geigy Black I-2R 6%* Ciba Geigy Black I-R + EXX/IPM (2:1) poor borderline 6% Ciba Geigy Black I-2R__________________________________________________________________________ *Compound precipitated out of solution when stored for more than 3 days.
Reasonable modifications and variations are possible from the foregoing disclosure without departing from either the spirit or scope of the present invention as defined by the claims.
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A fingerprinting system comprising means capable of releasably retaining a liquid and a liquid composition releasably retained in said means, said liquid composition comprising a leuco color-former coupound, a dialkyl phthalate wherein the alkyl group contains 1-3 carbon atoms, a substrate for receiving fingerprints associated therewith, said substrate being coated on at least a portion of one surface thereof with a color developing substance comprising a phenol/aldehyde condensation product produced by the reaction together of an alkyl-substituted salicylic acid, an alkyl-substituted phenol, and an aldehyde, said condensation product having been reacted with a metal source.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/599,608 entitled “SUPER-RESOLUTION BASED ON FREQUENCY DOMAIN INTERFEROMETRIC PROCESSING OF SPARSE MULTI-SENSOR MEASUREMENTS” filed Aug. 6, 2004, the entirety of the disclosure of which is expressly incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
This application is a subject invention under Contract/Grant No. HQ0006-03-C-0049 with the United States Government, and as such the United States Government has rights therein.
BACKGROUND OF THE INVENTION
The present invention relates in general to a method of obtaining super-resolution in range for sensor systems such as electromagnetic, acoustic, electro-optics and other spectral regimes particularly where the individual sensors are limited in bandwidth. More particularly, the present invention relates to a method for producing two-dimensional (range-Doppler) images with super-resolution from a system having multiple narrow-band radars.
For both radar and sonar systems, high range resolution is a desirable property to improve the ability of the sensor in regard of target identification and discrimination. A desire to obtain resolution beyond the operating bandwidth defined by the Fourier operation has led to numerous techniques such as the Burg Algorithm which extrapolates data in the frequency domain. However, the resolution achieved by the Burg Algorithm is limited to a factor of 2 or 3 (see P. R. Wu, “A Criterion for Radar Resolution Enhancement with Burg Algorithm”, IEEE Trans., Aerospace and Electronic Systems, Vol. 31, No. 3, July, 1995), the disclosure of which is expressly incorporated herein by reference.
Other techniques have been proposed for fusing the data collected by two sensors with different operating frequencies. These techniques use estimated signals derived from two different bands to fill the empty gap so as to create a continuous ultra-wide bandwidth. The fidelity of these estimated signals is directly proportional to the inherent bandwidths of the two sensors. See “J. E. Piou, K. M. Cuomo and J. T. Mayhan, “A State-Space Technique for Ultrawide-Bandwidth Coherent Processing”, Technical Report 1054, Lincoln laboratory, Massachusetts Institute of Technology, 20 Jul. 1999 and K. M. Cuomo, U.S. Pat. No. 5,945,940, “Coherent Ultra-wideband Processing of Sparse Multi-sensor/Multi-spectral Radar Measurements” Aug. 31, 1999, the disclosures of which are expressly incorporated herein by reference. However, none of these prior art techniques has taken advantage of the interferometer principle; and therefore, full-resolution benefit implied by the frequency separation of the sensors has not been achieved.
BRIEF SUMMARY OF THE INVENTION
A process is provided by the present invention to obtain super-resolution from sparse multi-sensor measurements by applying the principles of interferometry to the frequency domain. The process involves comparing the phase of signals received by the sensors operating in separate frequency bands to obtain range estimates. Ambiguities in the range estimates are removed by phase comparisons made within each band.
The removal of range ambiguities is performed simultaneously over a number of successive pulses in time to reduce the number of frequency-shifted pairs required in each band. By processing in two dimensions the bandwidth requirements for each band is reduced.
The process can extend to a system having more than two sensors to achieve super-resolved range-doppler images. Further, the multiple sensors can coexist on the same platform or be physically separate from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
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.
These as well as other features of the present invention will become more apparent upon reference to the drawings wherein:
FIG. 1 is a block diagram for obtaining super-resolution based on frequency domain interferometric processing of sparse multi-sensor measurement;
FIG. 2 is a flow chart showing the method for obtaining super-resolution based on frequency domain interferometric processing of sparse multi-sensor measurement; and
FIG. 3 is an example showing the dual-band interferometric processing of synthetic static-range data collected on three equal-amplitude scattering centers.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 , the theoretical basis for frequency-domain interferometry can be illustrated by a system using a single scattering center illuminated by radar or sonar sensors operating in two frequency bands, namely, an upper band and a lower band separated from each other by ΔF Hz. As shown, the system has two sensors (transceivers) 12 and 14 operative to generate and transmit acoustic, optical or electromagnetic illumination and to receive reflected signals of the illumination from the scattering center 10 . The bandwidth of the upper and lower bands is denoted as B. As the resolution obtained from the system is proportional to the frequency separation ΔF between the upper and lower bands, the frequency separation ΔF is preferably no less than ten times the bandwidth B. That is, the bandwidth B is no more than 10% of the frequency separation ΔF.
The location of the scattering center 10 is referred as a range r 0 with respect to a phase reference origin. When illumination is generated by the upper band and lower band transceivers 12 and 14 , reflected signals of the illumination from the scattering center 10 are received at each of the transceivers 12 and 14 . The reflected signals received at the transceivers 12 and 14 are then input to a processing subsystem 16 , such as a mutual coherent processing subsystem. Preferably, the signals received by each of the transceivers 12 and 14 have already been time aligned (including but not limited to interpolation, if necessary) using time marks provided by synchronized clocks at the transceivers 12 and 14 . The mutual coherent processing subsystem 16 includes an inter-band processing unit 16 a operative to process the time-aligned sampling signals obtained from different bands, and an intra-band processing unit 16 b operative to process the time-aligned sampling signals obtained from the same bands.
The sampling signals from two transceivers 12 and 14 superposed and processed in the mutual coherent processing subsystem 16 are typically in the form including a base-band in-phase component I mn and a base-band orthogonal component Q mn expressed as:
[ I mn Q mn ] = [ a cos ( ψ mn ) a sin ( ψ mn ) ] , ( 1 )
where α is the amplitude, ψ mn is the phase of the reflected signal, and the indices m and n indicate the sampling time t m and frequency f n . For simplicity, the amplitude is assumed independent of time and frequency. In general, the phase can be expressed as:
ψ mn =4 πf n ( r 0 +{dot over (r)}t m )/ν (2),
where {dot over (r)} is the range rate, and ν is the wave propagation velocity of the sampling signals. For the time-aligned signals obtained from different bands separated by ΔF, the range r 0 can be solved by the relationship with the phase difference Δψ between the bands at a common time as:
r 0 =(ν/4π)(Δψ/Δ F )+ kΔr (3),
where Δr=ν/(2ΔF) is the range interval, and k is an unknown integer. As k is unknown, the phase difference Δψ is determined within an unknown integral multiple of 2π, so that ambiguity of the range r 0 arises.
To remove the ambiguity of the range r 0 , sampling signals are obtained at different frequencies of the same band. That is, the upper band and/or the lower band are divided into a plurality of segments with a bandwidth of δF, and sampling signals are obtained from adjacent segments. The sampling signals received at the transceivers 12 and 14 are input to the intra-band processing unit 16 b of the mutual coherent processing subsystem 16 . Similar to the above, the range estimate r can be obtained by evaluating the phase difference δψ between adjacent samples within the same band. The range estimate can be expressed as:
r 0 ′=(ν/4π)(δψ/δ F ) (4).
The range estimate r 0 ′ is typically less precise than the range r 0 estimated by inter-band samples because the phase difference δψ which is much smaller than the phase difference Δψ, is more perturbed by noise. However, the range estimate r 0 ′ can be used to identify which of the ambiguous range estimates r 0 is the correct one. In other words, the range estimate r 0 ′ can be used to determine the unknown integer k.
If the above process extends over more than one time-sample interval, the greater dimensionality as provided significantly reduces the bandwidth B requirement for each individual band. In addition, the process over a plurality of time-sample intervals allows the Doppler processing to be included, such that both the range and the range rate of the target can be evaluated. More specifically, the range is evaluated as described as above, which uses phase differences between samples separated in frequency, while the range rate is evaluated as {dot over (r)}=(ν/4πf n )(dψ/dt), where dψ is the phase difference between samples separated in time and dt is the time sampling interval.
FIG. 2 provides a flow chart of the method of the present invention to obtain the super-resolution based on frequency domain interferrometric processing of sparse multi-sensor measurements.
In a more general case where the target contains many scattering centers with various amplitudes, a successful solution depends on distinguishing between the centers by using techniques from linear algebra such as those based on subspace rotational invariance. The solution can also include Doppler processing, and so be used to form range-Doppler images of the target.
When there are two or more scattering centers, the signals reflected from each of the scattering centers for each band can be summed up or superposed in the complex form of I mn +iQ mn , where m and n indicates the sampling time and frequency. Therefore, there are m×n sampling signals obtained from each band, which can be expressed by a matrix including m×n elements. The sampling signals reflected from all the scattering centers for the upper and lower bands F 1 and F 2 at a specific time t 0 +mδt and frequency f 0 +nδf can thus be expressed as w mn ub and w mn lb . Therefore, the sampling signals at all time and frequencies intervals for the upper and lower bands can thus be expressed as:
W
1
=
[
w
11
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12
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and
(
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The canonical expression of each element of the above matrices can be written aexp(imα+inβ), where a is the amplitude and α and β are the data frequencies in radians per row or column of the sum. In this embodiment, the upper band is at the frequency F 1 and the lower band is at the frequency F 2 , and the frequency separations between the upper and lower bands is ΔF, which is equal to “F 1 –F 2 ”. The canonical form of the dual data arrays W 1 and W 2 implies that, for the separate contribution of each scattering center to the data arrays, the phase increment from sampling signal to sampling signal down the columns is the constant α, and the phase increment from sampling signal to sampling signal down along the row is the constant β. The same is true of the contribution of individual scattering center to any sub-block of the sampling signals. Namely, the contribution of individual scattering center to any sub-block of the arrays shifts in phase by α and β if the sub-block is shifted down by one row or right by one column.
To simplify the description, 3×3 arrays are used as examples for W 1 and W 2 in this embodiment. The arrays of sampling signals W 1 and W 2 are transformed into the matrices H 1 and H 2 as:
W 1 = [ w 11 ub w 21 ub w 31 ub w 12 ub w 22 ub w 32 ub w 13 ub w 23 ub w 33 ub ] ⟹ H 1 = [ w 11 ub w 21 ub w 12 ub w 22 ub w 21 ub w 31 ub w 22 ub w 32 ub w 12 ub w 22 ub w 13 ub w 23 ub w 22 ub w 32 ub w 23 ub w 33 ub ] ; and ( 7 ) W 1 = [ w 14 l b w 24 l b w 34 l b w 25 l b w 25 l b w 35 l b w 16 l b w 26 l b w 36 l b ] ⟹ H 2 = [ w 14 l b w 24 l b w 15 l b w 25 l b w 24 l b w 34 l b w 25 l b w 35 l b w 15 l b w 25 l b w 16 l b w 26 l b w 25 l b w 35 l b w 26 l b w 36 l b ] , ( 8 )
respectively.
The transformation process can be referred to “Two-dimensional ESPRIT with Tracking for Radar Imaging and Feature Extraction” by M. L. Burrows, IEEE Transactions on Antennas and Propagation, Vol. AP-52, No. 2, February 2004, which is expressly incorporated by reference hereinwith. Practically, the arrays typically have different sampling intervals in time and frequency. Therefore, the arrays need to be preconditioned by clock synchronization and interpolation to achieve common sampling intervals in both the time and frequency dimensions.
As expressed above, each of the sub-blocks is reshaped to form a row in the corresponding transformed matrix. The sub-block location sequence used to form the consecutive rows for two data arrays may be different based on the selection of degree of freedom. The rows originating from the array W 2 are stacked under those originating in the array W 1 as the Hankel Matrix H:
H
=
[
H
1
H
2
]
(
9
)
Therefore, each row of the Hankel Matrix H is a sub-block (sub-array) of the data arrays W 1 or W 2 . FIG. 2 shows the dual band interferometric process in the ideal case that there is no noise and the rank of the Hankel Matrix H is equal to the number of the scattering centers. The solution of the Hankel Matrix starts with deriving the eigenvector x s for the specific scattering center s and corresponding eigenvalue in the form of the coupled generalized-eigenvalue problems of H t(m>1) x s =exp(iα s )H t(m−1) x s and H f(n>1) x s =exp(iβ s )H f(n−1) x s , and x s is orthogonal to the elements of all the rows for all scattering centers except from the elements contributed from the scattering center s, and H t(m−1) , H t(m>1) , H f(n−1) and H f(n>1) are particular row and column selections from the master matrix H whose rows are elements of the sub-blocks of the arrays W 1 and W 2 reshaped as the row vectors as shown in the matrices H 1 and H 2 . Thereby, the eigenvalues α s and β s can be derived to obtain the unambiguous range and the unambiguous range rate from the following equations, respectively:
( H t(m>1) −e iα s H t(m−1) ) x s =0 (10); and
( H f(n>1) −e iβ s H f(n−1) ) x s =0 (11),
where m and n are positive integers and indicate the row and column numbers in the data matrices W 1 and W 2 .
As mentioned above, although the phase difference between the intra-band sampling signals provides the unambiguous range, the range is very much perturbed by noise due to the very small frequency difference between the adjacent sampling signals. Therefore, in this embodiment, when the unambiguous range and range rate are obtained by the derivation of phase α s and β s , a dual-band interferometric processing is used to obtain an ambiguous range by the inter-band phase, which is denoted as δ s in the following equation:
[ H 2 −e iδ s H 1 ]=0 (12).
Once the eigenvalues α s , β s , and δ s have been evaluated, the contribution H s from each scattering center to the Hankel Matrix H can be reconstructed as Hx s =a s H s x s , where a s is the amplitude of the scattering center and x s is the eigenvalue that selects just the contribution of the scattering center s to the Hankel matrix. The amplitude can then be expressed as:
a s =( y s h Hx s )/( y s h y s ), (13)
where y s =H s x s , and the superscript h denotes Hermitian conjugate.
A modification of the above procedure allows a general case of unknown number of scattering centers in the noise subspace is to use the singular value decomposition H=UΣV h first, such that the number S of significant singular values of H can be determined, where S is a diagonal matrix of singular values of H, and U and V are left and right unitary matrices of corresponding singular vectors, respectively. The row selections are then made from first S columns of U. Thereby, H t(m−1) , H t(m>1) , H f(n−1) and H f(n>1) are replaced by U t(m−1) , U t(m>1) , U f(n−1) and U f(n>1) . Again, m and n are positive integers. The coupled generalized-eigenvalue problems are then written as U t(m>1) =exp(iα s )U t(m−1) x s and U f(n>1) =exp(iβ s )U f(n−1) x s , implying that exp(imα s ) and exp(inβ s ) are the eigenvalues of the matrices U t(m−1) + U t(m>1) and U f(n−1) + U f(n>1) corresponding to their common eigenvector x s .
The third eigenvalue obtained from the dual-band interferometric processing can be obtained similarly. Specifically, two additional row selections U 1 and U 2 are made from U. They consist, respectively, of all the rows of U originating from W 1 and W 2 separately. The added eigenvalue problem is then U 2 =exp(iδ s )U 1 x s . The common eigenvalue is the same as exp(iδ s ), and the ambiguous range is r s =(ν/4π)(δ/ΔF)+kΔr, where Δr=ν/(2ΔF) and k is an unknown integer.
In practice, to ensure that the three lists of eigenvalues are properly identified in groups of three, having each group corresponding to a particular scatter, the eigenvalues x s are evaluated just once as the eigenvectors of the matrix sum U t(m−1) + U t(m>1) +U f(n−1) + U f(n>1) +U 1 + U 2 . The solution for the three eigenvalues are then exp(iα s )=x s h U t(m−1) + U t(m>1) x s , exp(iβ s )=x s h U f(n−1) + U f(n>1) x s , and exp(iδ s )=x s h U 1 + U 2 x s . This has the additional advantage that the same high resolution is obtained for all three evaluations.
The phase offset between two bands is likely to be greater than 2π. This makes the corresponding range estimate ambiguous. On the other hand, this large phase difference is more easily estimated accurately in the presence of noise. Therefore, it is preferred to use the less accurate unambiguous range estimate determined by the inter-column phase increment β to resolve the ambiguity in the more accurate but ambiguous range estimate determined by the inter-band phase increment δ.
The amplitudes can be evaluated by using V −1 x s instead of x s so as to select the contribution of the scattering centers from the U matrices evaluated in the singular value decomposition H=U V h , such that a s =(y x h Ux s )/(y s h y s ), where y s =H s V −1 x s .
Referring to FIG. 3 , a result of a dual-band interferometric processing of synthetic static-range data collected on three equal-amplitude scattering centers is shown. As shown, two 18 MHz-wide bands are centered at 424 MHz and 1,319.5 MHz. Five frequency samples with 4.5 MHz spacing, and twenty-five samples with 2-degree spacing are used in each band. The signal-to-noise ratio was set at 30 dB. The dimension of the sub-block is 3-by-2.
Different bands of the input data were used to generate the Fourier images in three of the panels. The whole 913.5-MHz filled band was used for the left one, and the two 18-MHz bands were used for the two middle panels. The right panel shows the locations of the scattering centers by interferometric processing of the data in just the two narrow bands. As shown, the dual band interferometric processing produces as good an image as conventional Fourier processing of the whole 913.5 MHz but uses only 4% of the bandwidth. Thus the effective resolution power has been increased by a factor of 25.
The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention. Further, the various features of this invention can be used along, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the invention is not to be limited by the illustrated embodiments but is to be defined by the following claims when read in the broadest reasonable manner to preserve the validity of the claims.
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A system for obtaining frequency domain interferometric super-resolution of a target scatterer, having a first and a second coherent transceivers, a mutual coherent sub-system and an estimation system. The first and second coherent transceivers are operative to produce a plurality of first and second sampling signals separated from each other by a predetermined frequency difference within the first and second sub-band, respectively. The mutual coherent sub-system is coupled to the first and second coherent transceivers to receive phase and amplitude of the first and second sampling signals, so as to evaluate an ambiguous range estimate from a pair of the first and second sampling signals and an unambiguous range estimate from a pair of the first and/or second sampling signals. The estimation system follows the mutual coherent sub-system to reconcile the ambiguous and unambiguous range estimates so as to obtain a target signature with a super-resolution defined by a frequency offset between the first and second sub-bands.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from Japanese Patent Application No. 2006-267440, filed on Sep. 29, 2006, the entire subject matter of which is incorporated herein by reference.
FIELD
Aspects of the invention relate to image forming apparatuses.
BACKGROUND
An image forming apparatus including a main mechanical part covered with a housing is known. The main mechanical part includes an ejection portion configured to eject a recording sheet that undergoes a printing process in an image forming portion. The image forming apparatus is provided with an upper sheet receiving portion disposed on an upper surface of the housing and a side sheet receiving portion disposed on a side of the housing, which are configured to receive a recording sheet ejected from the ejection portion. The image forming apparatus includes a guide portion disposed facing the ejection portion and configured to guide a recording sheet ejected from the ejection portion selectively to the upper or side sheet receiving portion when the guide portion slidingly contacts the recording sheet.
SUMMARY
Aspects of the invention provide an image forming apparatus in which the number of parts may be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative aspects of the invention will be described in detail with reference to the following figures in which like elements are labeled with like numbers and in which:
FIG. 1 is a side sectional view of a general structure of a laser printer as an image forming apparatus according to a first illustrative embodiment of the invention;
FIG. 2 is an enlarged side sectional view of the laser printer in which a rear cover is open according to illustrative aspects of the invention;
FIG. 3 is a side view of the laser printer to which a tray extension is attached according to illustrative aspects of the invention;
FIG. 4 is a perspective view of the tray extension according to illustrative aspects of the invention;
FIG. 5 is an enlarged perspective view of an upper sheet discharge tray according to illustrative aspects of the invention;
FIG. 6 is a perspective view of the laser printer in which the tray extension is stored in a storage recessed portion according to illustrative aspects of the invention;
FIG. 7 is a perspective view of the laser printer in which the tray extension is attached to the rear cover according to illustrative aspects of the invention;
FIG. 8 is an enlarged perspective view of the laser printer in which the tray extension is attached to the rear cover according to illustrative aspects of the invention;
FIG. 9 is a perspective view of a tray extension of a laser printer according to a second illustrative embodiment of the invention;
FIG. 10 is a perspective view of the laser printer in which the tray extension is stored in a storage recessed portion according to illustrative aspects of the invention;
FIG. 11 is a perspective view of the laser printer in which the tray extension is placed in a sheet receiving position according to illustrative aspects of the invention;
FIG. 12 is a perspective view of the laser printer in which the tray extension is attached to the rear cover according to illustrative aspects of the invention;
FIG. 13 is a side view of a laser printer according to a third illustrative embodiment of the invention where a tray extension is attached; and
FIG. 14 is a side view of a laser printer according to a fourth illustrative embodiment of the invention where a tray extension is attached to a rear cover.
DETAILED DESCRIPTION
A first illustrative embodiment of the invention will be described in detail with reference to FIGS. 1 to 8 . The image forming apparatus according to illustrative aspects of the invention is applied to a laser printer in this embodiment.
For purposes herein, aspects of the invention are shown in relation to an image carrier and developer carrier. In various aspects, the image carrier may include a photosensitive drum, photosensitive belt, or the combination of one of a photosensitive drum or belt and an intermediate transfer drum or belt. Further, the developer carrier may include a developer roller or other systems for conveying developer to the image carrier.
It is noted that various connections are set forth between elements in the following description. It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect.
As shown in FIG. 1 , a laser printer 1 is provided with a main mechanical part 1 A inside a housing 2 . The main mechanical part 1 A includes a sheet supply mechanical part 4 for supplying a recording medium (hereinafter referred to as a recording sheet 3 ), an image forming part 5 for forming an image on the supplied recording sheet 3 , and a sheet discharge mechanism 6 for discharging the recording sheet 3 on which the image has been formed. In the following description, the right side in FIG. 1 is regarded as a front of the laser printer 1 , and the left side in FIG. 1 is regarded as a rear of the laser printer 1 .
An upper surface of the housing 2 is downwardly recessed to provide an upper output tray 100 configured to receive a recording sheet 3 on which an image has been formed. The upper output tray 100 is provided with a receiving surface 101 inclining upwardly from rear to front of the laser printer 1 . A rear end of the receiving surface 101 is provided with a receiving portion 102 standing vertically. When a recording sheet 3 is discharged to the upper output tray 100 , the recording sheet 3 is placed on the receiving surface 101 and the trailing end of the recording sheet 3 is supported by the receiving portion 102 .
A front sidewall (on the left side in FIG. 1 ) of the housing 2 is formed with an opening 7 and is provided with a front cover 7 A configured to cover and uncover the opening 7 . When the front cover 7 A is opened, the opening 7 is released, and a process cartridge 20 is able to be attached to and removed from the main mechanical part 1 A through the opening 7 .
A rear sidewall (on the left side in FIG. 1 ) of the housing 2 is formed with an opening 115 , and is provided with a rear cover 116 configured to cover and uncover the opening 115 . As shown in FIG. 2 , the rear cover 116 is mounted to the rear sidewall of the housing 2 so as to pivot on an axis extending horizontally (in a direction passing through the sheet of FIG. 2 ) in a lower portion of the opening 115 . The rear cover 116 is pivotal between a closed position to cover the opening 115 shown in FIG. 1 and an open position to uncover the opening 115 shown in FIG. 2 . An inner surface of the rear cover 116 is provided with lock portions 117 ( FIG. 7 ) that protrude inwardly in a state where the rear cover 116 is in the closed position. The lock portions 117 are configured to engage a receiving portion (not shown) provided in the housing 2 , so that the rear cover 116 is maintained in the closed position against the housing 2 . When the rear cover 116 is in the open position, the inner surface of the rear cover 116 is designed so as to receive a recording sheet 3 that undergoes printing process. As shown in FIGS. 1 and 8 , an outer surface of the rear cover 116 is provided with a finger hook portion 128 for receiving a finger of a user. The finger hook portion 128 protrudes outward at an upper end of the rear cover 116 .
A sheet supply tray 9 is disposed in the lowermost part of the housing 2 , and is configured to hold a stack of recording sheets 3 on which images are to be formed. The sheet supply tray 9 can be pulled out toward the front.
The sheet supply tray 9 may be in the shape of a box with an open top. A sheet pressing plate 15 is disposed in a lower portion of the sheet supply tray 9 . A stack of recording sheets can be placed on an upper surface of the sheet pressing plate 15 . The sheet pressing plate 15 is pivotally supported at its rear portion (the left end of FIG. 1 ) so that its front portion (the right end of FIG. 1 ) is vertically movable.
A lever 17 is disposed at a front end of the sheet supply tray 9 to raise the front end of the sheet pressing plate 15 . The lever 17 is L-shaped in a cross sectional view in such a manner as to enclose the sheet pressing plate 15 from the front to the bottom. An upper end of the lever 17 is attached to a lever shaft 18 disposed at the front end of the sheet supply tray 9 . A rear end of the lever 17 contacts a lower surface of the front end of the sheet pressing plate 15 . When the lever shaft 18 rotates in a clockwise direction in FIG. 1 , the lever 17 pivots on the lever shaft 18 such that the rear end of the lever 17 raises the front end of the sheet pressing plate 15 . When the sheet supply tray 9 is removed from the housing 2 , the sheet pressing plate is configured to move downward under its own weight.
The sheet supply mechanical part 4 includes a sheet supply roller 10 disposed at the front end of and above the sheet supply tray 9 , and a pickup roller 12 disposed at the rear of the sheet supply roller 10 so as to contact an uppermost recording sheet 3 placed in the sheet supply tray 9 . A reverse guide 37 is disposed at a position facing a front half of a circumferential surface of the sheet supply roller 10 . The reverse guide 37 includes a guide surface 16 that is configured to guide a recording sheet 3 by reversing the sheet feed direction. The recording sheet 3 passes through a space defined between the circumferential surface of the sheet supply roller 10 and the guide surface 16 . A separation pad 11 is disposed in an entrance of the reverse guide 37 . The separation pad 11 is configured to be pressed into contact with the sheet supply roller 10 by an urging force of a spring. In the reverse guide 37 , a pinch roller 13 is disposed on a downstream side of the separation pad 11 . A paper dust removing roller 8 is disposed on a downstream side of the pinch roller 13 . The pinch roller 13 and the paper dust removing roller 8 face the sheet supply roller 10 .
The uppermost recording sheet 3 in the sheet supply tray 9 presses against the pickup roller 12 by the sheet pressing plate 15 , fed toward the entrance of the reverse guide 37 upon rotation of the pickup roller 12 , caught between the sheet supply roller 10 and the separation pad 11 , and singly separated from a stack of recording sheets 3 . The recording sheet 3 fed from between the pickup roller 12 and the separation pad 11 is caught between the sheet supply roller 10 and the pinch roller 13 . The recording sheet 3 is also caught between the sheet supply roller 10 and the paper dust removing roller 8 , ejected from an exit of the reverse guide 37 , and fed to register rollers 14 located on a downstream side of the sheet supply roller 10 .
The register rollers 14 include a pair of rollers, which are configured to correct skew of a recording sheet 3 and feed the recording sheet 3 to an image formation position of the image forming part 5 . The imaging forming part 5 is where a photosensitive drum 29 and a transfer roller 32 make contact.
The image forming part 5 includes a scanner unit 19 , a process cartridge 20 , and a fixing unit 21 .
The scanner unit 19 is disposed in an upper portion of the housing 2 . The scanner unit 19 includes a laser light source (not shown), a polygon mirror 22 , an fθ lens 23 , a reflecting mirror 24 , a lens 25 , and a reflecting mirror 26 . A laser beam emitted from the laser light source based on image data is deflected at the polygon mirror 22 , passes through fθ lens 23 , is deflected downward at the reflecting mirror 24 , and is directed to a surface of a drum body 34 of a photosensitive drum 29 in the process cartridge 20 , as shown by a dot-dash line in FIG. 1 .
The process cartridge 20 is disposed under the scanner unit 19 . The process cartridge 20 includes, in a frame 28 , a photosensitive drum 29 , a scorotron charger 30 , a developing cartridge 31 , a transfer roller 32 , and a cleaning brush 33 . The frame 28 is made up of an upper frame 27 A and a lower frame 27 B, which are separately formed and assembled with each other.
The photosensitive drum 29 is substantially cylindrically shaped, and includes a drum body 34 and a drum shaft 35 . The drum shaft 35 is supported by the upper frame 27 A and the drum body 34 is rotatably supported by the drum shaft 35 . The photosensitive drum 29 is rotatably provided on the drum shaft 35 in the upper frame 27 A.
The scorotron charger 30 is disposed diagonally above the photosensitive drum 29 to face it. The scorotron charger 30 is configured to charge the surface of the photosensitive drum 29 evenly and positively by a corona discharge generated from a charging wire (not shown) made of tungsten.
The developing cartridge 31 is shaped in a box that is open at the rear and detachably attached to the lower frame 27 B. The developing cartridge 31 includes a toner chamber 39 , a supply roller 40 , a developing roller 41 , and a layer-thickness regulating blade 42 .
The toner chamber 39 is formed as a front-side interior space of the developing cartridge 31 and is divided by a partition wall 43 . The toner chamber 39 is filled with a developing agent such as nonmagnetic single component toner which is to be positively charged. A coloring agent such as carbon black and wax can be added to the toner to form toner base particles. An external additive, such as silica, also can be added to the toner to improve fluidity.
The toner chamber 39 is provided with an agitator 44 . Toner in the toner chamber 39 is agitated by the agitator 44 and discharged from an opening 45 defined under the partition wall 43 toward the supply roller 40 .
The supply roller 40 is disposed at the rear of the opening 45 and is rotatably supported by the developing cartridge 31 . The supply roller 40 is made up of a roller made of an electrically conductive foam material and a metal roller shaft covered with the roller. The supply roller 40 is configured to rotate by an input from a motor (not shown).
The developing roller 41 is rotatably supported by the developing cartridge 31 so as to contact the supply roller 40 under compression at the rear. The developing roller 41 is configured to contact the photosensitive drum 29 when the developing cartridge 31 is attached to the lower frame 27 B. The developing roller 41 is made up of a roller formed of an electrically conductive rubber material and a metal roller shaft covered with the roller. The roller shaft protrudes from both sides of the developing cartridge 31 outwardly in a width direction substantially perpendicular to the front-rear direction (in a direction passing through the sheet of FIG. 1 ).
The roller of the developing roller 41 can be made by covering a roller body (made of a conductive urethane rubber or silicone rubber including carbon fine particles) with a coat layer of urethane rubber or silicone rubber including fluorine. The developing roller 41 is configured to receive a bias during image developing. The developing roller 41 is configured to be driven by a motor (not shown) and rotated in the same direction as the supply roller 40 .
The layer-thickness regulating blade 42 is provided with a blade body 46 made of a metal plate spring member and a pressing portion 47 having a generally semicircular shape in cross section, provided at a free end of the blade body 46 , and made of insulative silicon rubber. The layer-thickness regulating blade 42 is supported by the developing cartridge 31 in an upper portion of the developing roller 41 , and the pressing portion 47 presses against the developing roller 41 by an urging force of the blade body 46 .
Toner discharged from the opening 45 is supplied to the developing roller 41 upon rotation of the supply roller 40 , while being positively charged between the supply roller 40 and the developing roller 41 by friction. Toner supplied to the developing roller 41 goes between the pressing portion 47 of the layer-thickness regulating blade 42 and the developing roller 41 through the rotation of the developing roller 41 , and is further charged therebetween. The toner is carried as a thin layer of a fixed thickness on the developing roller 41 .
The transfer roller 32 is rotatably supported by the lower frame 27 B, and is disposed so that, when the upper frame 27 A is assembled with the lower frame 27 B, the transfer roller 32 vertically contacts the photosensitive drum 29 to form a nip between the transfer roller 32 and the photosensitive drum 29 . The transfer roller 32 is formed by covering a metal roller shaft with a roller made of a conductive rubber material. The transfer roller 32 is configured to be driven by a motor (not shown) and rotated in a direction opposite to the direction the photosensitive drum 29 rotates.
The cleaning brush 33 is attached to the lower frame 27 B and is disposed to contact the photosensitive drum 29 behind where the upper frame 27 A is assembled with the lower frame 27 B.
The surface of the photosensitive drum 29 is positively and uniformly charged by the scorotron charger 30 upon the rotation of the photosensitive drum 29 . The surface of the photosensitive drum 29 is exposed to the laser beam emitted from the scanner unit 19 by high speed scanning, and an electrical latent image is formed on the surface of the photosensitive drum 29 based on predetermined image data.
When toner positively charged and carried on the developing roller 41 contacts the photosensitive drum 29 upon the rotation of the developing roller 41 , it is supplied to the electrical latent image formed on the surface of the photosensitive drum 29 , where the potential has become low due to exposure to the laser beam. In this manner, the electrostatic latent image formed on the photosensitive drum 29 is developed with toner, a reversal takes place, and a toner image is formed on the photosensitive drum 29 .
The toner image carried on the photosensitive drum 29 is transferred onto a recording sheet 3 through the application of a bias 32 while the recording sheet 3 being fed by the register rollers 14 passes through a transfer position between the photosensitive drum 29 and the transfer roller 32 . The recording sheet 3 on which the toner image has been transferred is fed to the fixing unit 21 . Toner remaining on the photosensitive drum 29 after transferring is collected by the developing roller 41 . Foreign matter such as dust adhering to the photosensitive drum 29 after transfer is collected by the cleaning brush 33 .
The fixing unit 21 is disposed at a rear of the process cartridge 20 and includes a fixing frame 48 , and an ejection portion such as a heat roller 49 and a pressure roller 50 . The heat roller 49 and the pressure roller 50 are disposed within the fixing frame 48 .
The heat roller 49 includes a metal tube coated with fluorine resin and a halogen lamp configured to apply heat to the inside of the metal tube. The heat roller 49 is configured to be rotated by input from a motor not shown.
The pressure roller 50 is disposed facing the heat roller 49 in such a manner as to press the heat roller 49 from underneath. The pressure roller 50 is formed by covering a metal roller shaft with a roller formed of a rubber material. The pressure roller 50 is configured to rotate following the rotation of the heat roller 49 .
In the fixing unit 21 , toner transferred onto the recording sheet 3 at a transfer position is thermally fixed onto the recording sheet 3 while the recording sheet 3 passes through between the heat roller 49 and the pressure roller 50 . The recording sheet 3 on which toner has been fixed is fed to the sheet discharge mechanism 6 .
The sheet discharge mechanism 6 includes a guide portion such as a sheet discharge guide 113 , and a sheet discharge roller 110 configured to eject a recording sheet to the upper output tray 100 . In the laser printer 1 , a recording sheet 3 on which image has been thermally fixed is fed to either one of two feed paths, a first feed path 118 and a second feed path 119 . When the rear cover 116 is kept in the closed position, the recording sheet 3 being fed from between the heat roller 49 and the pressure roller 50 is guided to the upper output tray 100 via the first feed path 118 . When the rear cover 116 is kept in the open position, the recording sheet 3 is guided to the rear cover 116 via the second feed path 119 as shown in FIG. 2 .
The sheet discharge guide 113 is disposed on the downstream side from the heat roller 49 and the pressure roller 50 . The sheet discharge guide 113 is configured to guide the recording sheet 3 on which the image has been thermally fixed to the first feed path 118 or the second feed path 119 . The sheet discharge guide 113 is configured to rotate on an axis extending horizontally (in a direction passing through the sheet of FIG. 1 or 2 ) in association with the rotation of the rear cover 116 between the open position and the closed position. The sheet discharge guide 113 is provided with a guide surface 114 having a gradient inclined from rear to front in a position facing the heat roller 49 and the pressure roller 50 .
When the rear cover 116 is in the closed position as shown in FIG. 1 , the recording sheet 3 on which the image has been thermally fixed is guided to the first feed path 118 in sliding contact with the guide surface 114 of the sheet discharge guide 113 . When the rear cover 116 is in the open position as shown in FIG. 2 , the sheet discharge guide 113 is rotated counterclockwise in FIG. 2 , and the recording sheet 3 on which the image has been thermally fixed is guided to the second feed path 119 in sliding contact with the guide surface 114 of the sheet discharge guide 113 . In this way, the recording sheet 3 is selectively guided to the first feed path 118 or the second feed path 119 .
Guide ribs 120 are disposed on an inner side of the rear cover 116 , which faces inside of the laser printer 1 when the rear cover 116 is kept in the closed position in such a manner as to protrude at a downstream side of the sheet discharge guide 113 . The guide ribs 120 are arranged in an erect manner and extend along a direction where the recording sheet 3 is ejected from between the heat roller 49 and the pressure roller 50 . Each guide rib 120 is formed with an arc surface 121 having an edge substantially arcuately shaped in a side view. The recording sheet 3 guided to the first feed path 118 by the sheet discharge guide 113 is guided to the upper output tray 100 by sliding contact with the arc surface 121 . The arc surface 121 is connected to the sheet discharge roller 110 at a downstream side.
The sheet discharge roller 110 is made by covering a metal roller shaft 111 with a roller made of a rubber material, and is configured to be driven by a motor (not shown) and rotated counterclockwise. An auxiliary roller 112 is disposed ahead of the sheet discharge roller 110 in the downstream direction to face the sheet discharge roller 110 . The auxiliary roller 112 is rotated upon the rotation of the sheet discharge roller 110 . The recording sheet 3 fed from a downstream end of the arc surface 121 is caught between the sheet discharge roller 110 and the auxiliary roller 112 , and fed to the receiving surface 101 of the upper output tray 100 .
As shown in FIG. 2 , when the rear cover 116 is placed in the open position, the recording sheet 3 guided to the second feed path 119 by the sheet discharge guide 113 is fed from between the heat roller 49 and the pressure roller 50 to the rear cover 116 .
A tray extension 122 will be described with reference to FIG. 3 .
The tray extension 122 is attachable to the rear cover 116 as shown by a solid line in FIG. 3 and the upper output tray 100 as shown by a double dotted line in FIG. 3 . The tray extension 122 is configured to receive and prevent an ejected recording sheet 3 from hanging over and slipping off the rear cover 116 or the upper output tray 100 . When a recording sheet 3 is ejected to the rear cover 116 by the sheet discharge guide 113 and the guide ribs 120 , the tray extension 122 is attached to an outer end of the rear cover 116 which is on a downstream side in a direction where the recording sheet 3 is ejected (hereinafter referred to as a sheet ejection direction). Alternatively, when a recording sheet 3 is ejected to the upper output tray 100 by the sheet discharge guide 113 and the guide ribs 120 , the tray extension 122 is attached to an outer end of the upper output tray 100 which is on a downstream side in the sheet ejection direction.
The tray extension 122 is made of a synthetic resin and has a plate-like structure as shown in FIG. 4 , and is slightly curved on one surface. As shown in FIG. 3 , the tray extension 122 is attached to the housing 2 with the curved surface facing upward. The tray extension 122 has a recessed portion 125 at its lower part in FIG. 4 to prevent collision with the guide ribs 120 of the rear cover 116 . The tray extension 122 is provided with a pair of leg portions 129 at lower side edges to define the recessed portion 125 therebetween. The leg portions 129 are deformable in a width direction of the tray extension 122 (in the left-right direction in FIG. 4 ). The leg portions 129 have protrusions 123 protruding outwardly at outer edges of the leg portions 129 . When the protrusions 123 are engaged in recessed portions 124 formed in the upper output tray 100 or through holes 130 formed in the rear cover 116 , the tray extension 122 is attached to the upper output tray 100 or the rear cover 116 .
As shown in FIGS. 1 and 7 , a tray extension storing portion 126 is recessed downwardly at the front portion of the upper output tray 100 (on the right side of FIG. 1 ). The tray extension storing portion 126 is configured to store the tray extension 122 therein. The recessed portions 124 are recessed on the downstream side in the sheet ejection direction on both sidewalls of the tray extension storing portion 126 as shown in FIG. 5 , so as to engage the protrusions 123 of the tray extension 122 . By engagement of the protrusions 123 with the recessed portions 124 , the tray extension 122 is rotatably attached to the upper output tray 100 . The tray extension 122 is rotatable between a storage position where the tray extension 122 is stored within the tray extension storing portion 126 as shown in FIGS. 1 and 6 and a sheet receiving position shown by a double dotted line in FIGS. 3 and 7 . When the laser printer 1 is not used, the tray extension 122 can be rotated to the storage position and stored within the tray extension storing portion 126 . As shown in FIGS. 5 and 6 , finger recesses 127 for allowing a user to place his/her finger on the side edge of the tray extension 122 are provided at the rear side of the tray extension storing portion 126 . The user places his/her finger in the finger recess 127 to raise the tray extension 122 from the storage position to the sheet receiving position.
As shown in FIGS. 3 and 7 , when the tray extension 122 is attached to the upper output tray 100 and placed in the sheet receiving position, the tray extension 122 protrudes from the outer edge of the upper output tray 100 on the downstream side (right side in FIG. 3 ) in the sheet ejection direction.
As shown in FIG. 8 , the through holes 130 to engage the protrusions 123 of the tray extension 122 are formed in the upper end portion of the rear cover 116 facing each other in the width direction of the laser printer 1 . As shown in FIGS. 7 and 8 , when the rear cover 116 is in the open position, the tray extension 122 is attached to the upper end portion of the rear cover 116 . The tray extension 122 is attached to the rear cover 116 , and the guide ribs 120 fall within the recessed portion 125 of the tray extension 122 , so that the tray extension 122 is prevented from evacuating from the guide ribs 120 .
As shown in FIGS. 3 and 7 , when the tray extension 122 is attached to the rear cover 116 , the tray extension 122 protrudes from the outer edge of the rear cover 116 on the downstream side (left side in FIG. 3 ) in the sheet ejection direction.
The operation and advantages of the laser printer 1 will be described for a case when the recording sheet 3 is ejected to the upper output tray 100 . The rear cover 116 is rotated and kept in the closed position. After closing the rear cover 116 , the sheet discharge guide 113 is rotated to a position to guide the recording sheet 3 to the first feed path 118 as shown in FIG. 1 .
The tray extension 122 is attached to the upper output tray 100 by deforming the leg portions 129 inwardly in the width direction to engage the protrusions 123 of the tray extension 122 with the recessed portions 124 of the upper output tray 100 . The tray extension 122 is rotated to the sheet receiving position. When the tray extension 122 is already attached to the upper output tray 100 and stored in the tray extension storing portion 126 , the user places his/her finger in the finger recess 127 , and raises the tray extension 122 to the sheet receiving position.
A recording sheet 3 undergoes a printing process in the image forming part 5 and is ejected from the heat roller 49 and the pressure roller 50 . The recording sheet 3 is guided to the first feed path 118 in sliding contact with the guide surface 114 of the sheet discharge guide 113 , and then guided to the sheet discharge roller 110 in sliding contact with the curved surface 121 of the guide rib 120 . The recording sheet 3 is ejected from between the sheet discharge roller 110 and the auxiliary roller 112 toward the upper output tray 100 .
The recording sheet 3 ejected to the upper output tray 100 is loaded on the upper output tray 100 and the tray extension 122 . The tray extension 122 is attached to the upper output tray 100 so as to protrude from the outer edge of the downstream side in the sheet ejection direction of the upper output tray 100 . Thus, even when a large-sized recording sheet 3 is used, the recording sheet 3 is received by the tray extension 122 thereby preventing the recording sheet 3 from hanging over and slipping off the upper output tray 100 .
When printing is completed, the tray extension 122 is rotated from the sheet receiving position to the storage position, so that the tray extension 122 is stored in the tray extension storing portion 126 of the upper output tray 100 . Thus, when the laser printer 1 is not used, the tray extension 122 can be prevented from inadvertently being detached from the laser printer 1 and getting damaged due to a careless collision with an object.
The operation and advantages of the laser printer 1 will be described for a case when the recording sheet 3 is ejected to the rear cover 116 . The user places his/her finger in the finger hook portion 128 , and pulls the rear cover 116 outward to rotate it from the closed position to the open position. Following the movement of the rear cover 116 , the sheet discharge guide 113 is also rotated to a position to guide the recording sheet 3 to the second feed path 119 as shown in FIG. 2 .
When the tray extension 122 is attached to the upper output tray 100 , the tray extension 122 can be removed from the upper output tray 100 by deforming the leg portions 129 of the tray extension 122 inward in the width direction to disengage the protrusions 123 and the recessed portions 124 . When the tray extension 122 is not attached to the upper output tray 100 or if another tray extension will be used, the removal procedure of the tray extension 122 can be omitted.
The leg portions 129 of the tray extension 122 are deformed inward in the width direction, and the protrusions 123 are engaged in the through holes 130 of the rear cover 116 . In this manner, the tray extension 122 is attached to the rear cover 116 .
The recording sheet 3 undergoes a printing process in the image forming part 5 . The printed recording sheet 3 is ejected from the heat roller 49 and the pressure roller 50 . The recording sheet 3 is guided to the second feed path 119 in sliding contact with the guide surface 114 of the sheet discharge guide 113 , and ejected to the rear cover 116 .
The recording sheet 3 ejected to the rear cover 116 is received by the rear cover 116 and the tray extension 122 . The tray extension 122 is attached to the rear cover 116 so as to protrude from the outer edge of the downstream side in the sheet ejection direction of the rear cover 116 . Thus, even when a large-sized recording sheet 3 is used, the recording sheet 3 can be received by the tray extension 122 thereby preventing the recording sheet 3 from hanging over and slipping off the rear cover 116 .
When printing is completed, the tray extension 122 can be removed from the rear cover 116 by deforming the leg portions 129 of the tray extension 122 inwardly in the width direction and disengaging the protrusions 123 from the through holes 130 . Then, the rear cover 116 can be rotated to the closed position to close the opening 115 so that the rear cover 116 is kept closed. After that, the tray extension 122 can be attached to the upper output tray 100 , and rotated so that the tray extension 122 can be stored in the tray extension storing portion 126 of the upper output tray 100 .
A tray extension 122 can be attached to each of the upper output tray 100 and the rear cover 116 to prevent a large-sized recording sheet from hanging over and slipping away from the upper output tray 100 or the rear cover 116 . However, this increases the number of parts and leads to the increased cost.
In this illustrative embodiment, when the recording sheet 3 is ejected to the upper output tray 100 , the tray extension 122 is attached to the upper output tray 100 , and when the recording sheet 3 is ejected to the rear cover 116 , the tray extension 122 can be attached to the rear cover 116 . With this structure, when an image is formed on a large-sized recording sheet 3 , the single tray extension 122 can prevent the recording sheet 3 from hanging over and slipping off the upper output tray 100 or the rear cover 116 . Also, the number of parts in the laser printer 1 can be reduced. As the laser printer 1 is configured to eject a recording sheet 3 to the upper output tray 100 or the rear cover 116 selectively, it is only necessary to attach the tray extension 122 to either one of the upper output tray 100 and the rear cover 116 onto which the recording sheet 3 is ejected.
In this illustrative embodiment, when the recording sheet 3 is not ejected from a side of the laser printer 1 , the rear cover 116 can be placed in the closed position to close the opening 115 . As such, foreign matter such as dust and dirt can be prevented from entering the housing 2 through the opening 115 when the rear cover 116 is closed.
By placing the rear cover 116 in the closed position, the recording sheet 3 can be guided to the first feed path 118 by the sheet discharge guide 113 and the guide ribs 120 , and then to the upper output tray 100 .
A second illustrative embodiment of the invention will be described with reference to FIGS. 9 to 12 . In FIGS. 9 to 12 , a tray extension 222 is a variant of the tray extension 122 of the first embodiment, parts substantially equivalent to those described above are denoted by the same reference numerals, and descriptions therefor will be omitted.
As shown in FIG. 9 , the tray extension 222 is provided with a pair of cutout portions 231 close to lower side edges of the tray extension 222 to define leg portions 229 , which are deformable in the width direction of the tray extension 222 (in the left-right direction in FIG. 9 ).
As shown in FIGS. 10 and 11 , the tray extension 222 can be attached to the upper sheet discharge tray 100 rotatably between the storage position (in FIG. 10 ) and the sheet receiving position (in FIG. 11 ).
As shown in FIG. 12 , the tray extension 222 can be attached to the upper end of the rear cover 116 in the open position. Although it is not shown, the upper end of the rear cover 116 can be formed with a clearance groove for separating a lower end of the tray extension 222 from the rear cover 116 when the tray extension 222 is attached to the rear cover 116 . Thus, the recessed portion 125 can be omitted from the tray extension 222 .
A third illustrative embodiment of the invention will be described with reference to FIG. 13 . In FIG. 13 , a tray extension 322 is a variant of the tray extension 122 of the first illustrative embodiment. Parts substantially equivalent to those described above are denoted by the same reference numerals, and descriptions therefor will be omitted.
The tray extension 322 is shaped like a plate so that the front side and the back side are indistinguishable, e.g. reversibly used. Thus, the tray extension 322 is attachable to the upper output tray 100 and the rear cover 116 without paying attention to the front and back sides of the tray extension 322 .
According to the third illustrative embodiment, this structure can reduce workload of the user because there is no need to confirm the front side and the back side of the tray extension 322 when the user attaches the tray extension 322 to the laser printer 1 .
A fourth illustrative embodiment of the invention will be described with reference to FIG. 14 . In FIG. 14 , a tray extension 422 is a variant of the tray extension 122 of the first illustrative embodiment. Parts substantially equivalent to those described above are denoted by the same reference numerals, and descriptions therefor will be omitted.
The tray extension 422 is rotatably attached to the rear cover 116 by engaging the protrusions 123 in the through holes 130 . The tray extension 422 is rotatable between a storage position shown by the double dotted line in FIG. 14 and a sheet receiving position shown by the solid line in FIG. 14 . In the storage position, the tray extension 422 folds toward a side of the rear cover 116 on which the guide ribs 120 are disposed so as not to extend off the outer edge of the rear cover 116 . In the sheet receiving position, the tray extension 422 extends outwardly from the outer edge of the rear cover 116 in the sheet ejection direction. The tray extension 422 is formed with the recessed portion 125 for separating the guide ribs 120 from the tray extension 422 when the tray extension 422 is in the storage position.
A dimension L of the tray extension 422 from an end where the protrusion 123 is disposed to an end opposite of the protrusion 123 is set so that, when the rear cover 116 is placed in the open position and the tray extension 422 is rotated clockwise from the sheet receiving position to the storage position as shown in FIG. 14 , the tip end of the tray extension 422 is maintained out of contact with an upper end of the housing 2 defining the opening 115 .
According to the fourth illustrative embodiment, after the recording sheet 3 is printed and ejected to the rear cover 116 , the tray extension 422 can be rotated from the sheet receiving position to the storage position. Then, the rear cover 116 can be rotated and maintained in the closed position where the opening 115 is closed against the housing 2 . Thus, when the laser printer 1 is not used, the tray extension 422 can be prevented from inadvertently being detached from the laser printer 1 and getting damaged due to a careless collision with an object.
According to the fourth illustrative embodiment, the tray extension 422 can be stored while being attached to the rear cover 116 . This structure can save the user, who often directs a recording sheet 3 via the rear cover 116 , from having to remove the tray extension 422 from the rear cover 116 after printing.
Although the recording sheet 3 may be assumed to be plain paper in the above illustrative embodiments, the recording sheet 3 may be another medium such as a transparency made of a synthetic resin.
In the above illustrative embodiments, the rear cover 116 also serves as a side sheet receiving portion, but is not limited to such a configuration. The rear cover 116 and the side sheet receiving portion may be formed individually, and the side sheet receiving portion may be attached to the housing 2 when a recording sheet 3 is ejected to a side of the laser printer 1 .
In the above illustrative embodiments, the sheet discharge guide 113 is configured to rotate along with the rotation of the rear cover 116 to guide the recording sheet 3 to the first feed path 118 or second feed path 119 . However, the sheet discharge guide 113 may be configured to not rotate along with the rotation of the rear cover 116 . In other words, the user may select whether the recording sheet 3 is ejected from an upper portion of the laser printer 1 or a side portion thereof, and change the position of the sheet discharge guide 113 according to the selection.
In the above illustrative embodiments, the guide ribs 120 are disposed on the inner surface of the rear cover 116 . However, the guide ribs 120 may be disposed in the housing 2 so as to face the heat roller 49 and the pressure roller 50 to guide the recording sheet 3 to the first feed path 118 by sliding contact therewith.
Although illustrative embodiments of the invention have been described in detail herein, the scope of the invention is not limited thereto. It will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the invention. Accordingly, the illustrative embodiments disclosed herein are only exemplary. It is to be understood that the scope of the invention is not to be limited thereby, but is to be determined by the claims which follow.
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An image forming apparatus having a sheet support is described. Using one or more configurations, the number of parts for the sheet support may be reduced.
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CROSS REFERENCE TO RELATED DOCUMENTS
The present invention relates to a safety syringe as disclosed in Disclosure Document No. 245,403 filed Feb. 12, 1990.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a syringe. More particularly the syringe includes a safety sheath selectively movable by one hand to positions whereby the needle may be exposed or covered, one of the needle covering positions being automatically locked when the sheath is moved thereto.
2. Background of the Prior Art
Protection for medical personnel from inadvertent contact with contaminated syringe needles has become an increasing concern particularly because of the severity of certain infectious diseases which have developed. For example, the AIDS virus has been shown to be spread to persons who come into contact with a contaminated needle after the needle was used for a patient carrying the virus.
Numerous attempts have been made to protect medical personnel, patients and anyone in the area when syringes are used by providing various shielding devices for the needles. For example, U.S. Pat. No. 4,969,877 relates to a syringe which includes an outer casing into which the needle may be retracted after use. U.S. Pat. No. 4,973,316 relates to a one handed retractable sheath safety syringe. A number of other attempts at providing protection for safety syringe needles have been made.
None of the safety devices developed to date provide relatively simple and quick one hand application whereby the user may simply slide a protective device into several positions with one position being a locked position which is irreversible by normal action of the user. Further, there remains a need for such safety syringes which would be usable as an injecting syringe or as an aspirating syringe, all with one hand operation, while being simply automatically convertible to a configuration whereby the needle is covered and protected while preventing inadvertent re-exposure of the needle. The present invention provides such a safety syringe.
SUMMARY OF THE INVENTION
A syringe which comprises a needle body having a proximal end and a distal end, a needle attached to the distal end of the needle body, means for drawing fluid into the needle body through the needle, and a protective sheath configured and dimensioned to be positioned about the needle body and movable between a first distal position whereby the needle is shielded by the sheath and a proximal position whereby the needle is exposed. The syringe includes means to releasably retain the protective sheath in the first distal position, means to releasably retain the protective sheath in the proximal position, and means to retain the protective sheath in a second distal position after use whereby the needle is protected by the sheath. Preferably, the sheath automatically becomes locked in the second distal position when it is moved to this position.
In a preferred embodiment the needle body has a proximal end and a distal end and defines a fluid chamber. The needle is attached to the distal end of the body and communicates with the fluid chamber. Means is provided for manually drawing fluid into the chamber through the needle and the protective sheath is positioned about the needle body and movable between a first distal position whereby the needle is shielded by the sheath and a proximal position whereby the needle is exposed. Means to releasably retain the sheath in the first distal position is provided and means to releasably retain the protective sheath in the proximal position is provided. The syringe includes means to lockingly retain the protective sheath in a second distal position, the second distal position being distal of the first distal position whereby the needle is protected from unwanted contact after use.
Preferably the needle body is an elongated cylindrical member defining the inner fluid chamber and the fluid chamber is cylindrically shaped. A plunger assembly is positioned within the inner fluid chamber for drawing or expelling fluids with respect thereto. The needle body includes a plurality of slots dimensioned, positioned and configured for reception of correspondingly shaped pegs which extend inwardly of the protective sheath to retain the sheath in at least one of a plurality of selective positions relative to the needle body.
At least two of the slots in the needle body are positioned in the proximal portion of the needle body and are configured for reception of at least two correspondingly dimensioned pegs on the safety sheath to retain the safety sheath in the proximal position relative to the needle body whereby the needle is exposed for use. At least two of the slots are positioned in the distal portion of the needle body and are configured for reception of at least two correspondingly dimensioned pegs on the safety sheath to retain the safety sheath in the first distal position relative to the needle body, whereby the needle is covered. Further, at least two of the slots in the needle body are positioned distally of the first mentioned distal slots for reception of at least two of the pegs on the safety sheath, the pegs being dimensioned, positioned and configured to lockingly retain the safety sheath in the second distal position relative to the needle body.
The slots which retain the safety sheath in the second distal position are configured to retain the correspondingly configured and positioned locking pegs on the safety sheath in a manner whereby the locking pegs are not removable from the slots by normal action of the user. Further, the locking slots in the needle body are each positioned adjacent and distal of a ramped surface thereon, the ramped surface being adapted and configured for slidable reception of the locking pegs on the safety sheath to facilitate slidable entry of the locking pegs into the locking slots positioned distally of the ramped surfaces. The locking pegs on the safety sheath include a ramped surface substantially parallel to the ramped surface on the needle body to facilitate slidable engaged reception of the locking pegs into the locking slots.
In the safety syringe according to the invention, the locking pegs are attached to the safety sheath in a manner to be resiliently movable in a direction away from the needle body such that the pegs are resiliently biased in a direction toward the locking slots on the needle body to lock the position of the safety sheath in the second distal position. The ramped surface on the needle body extends in a direction radially outwardly of the needle body from the proximal end to the distal end of the ramped surface. The ramped surface on the peg attached to the safety sheath extends in a direction radially outward toward the inner surface of the safety sheath in a direction from the proximal end to the distal end of the ramped surface Further, the safety sheath is constructed of a resilient plastic material and the locking pegs are attached to strips formed integrally with the safety sheath and are adapted to be resiliently biased inwardly toward the safety sheath. The plastic material is transparent or translucent but may be opaque if desired. Such plastics as polyethylene polypropylene and polycarbonate are contemplated, but other suitable materials may be used.
The safety sheath includes two elongated strips attached to the safety sheath at their distal ends and resiliently biased inwardly toward the safety sheath. Also two similar locking strips are attached at their proximal ends and include the locking pegs.
Each elongated strip has an endless circular loop positioned at the proximal end, each loop being dimensioned for reception of one of the user's fingers. A plunger assembly is positioned within the needle body and adapted for drawing fluids therein through the needle by vacuum or out of the needle body by pressure. A finger loop is connected to the plunger assembly for movement of the plunger assembly in distal and proximal directions. The needle body includes at least one guide track extending along the length thereof and dimensioned for slidable reception of a correspondingly dimensioned peg extending inwardly of the inner surface of the safety sheath to retain the relative angular orientation between the safety sheath and the needle body. Preferably, at least four of the guide tracks are provided on the safety sheath and at least four of the correspondingly positioned and dimensioned pegs are provided. The tracks and the pegs are distributed approximately equally about the needle body to maintain rigidity and minimize lateral play within the safety sheath and the needle body. The elongated strips and the finger loops are integrally molded with the safety sheath in a manner which facilitates outward movement of the strips with respect to the safety sheath while the distal end of the strips are integrally attached to the safety sheath. The proximal ends of the locking strips are integrally molded with the safety sheath.
A method is disclosed for using a syringe having a hollow medical needle whereby the needle is protected from contact therewith before and after use, comprising providing a safety sheath in a first distal position whereby the needle is shielded prior to use, releasing the safety sheath and moving same to a proximal position whereby the needle is exposed for use, and advancing the safety sheath to a second distal position whereby the needle is protected by the safety sheath, the safety sheath having means to be locked into the second distal position whereby movement of the safety sheath to a position proximal thereof by the user is prevented.
According to the method the syringe includes an elongated needle body and the needle is attached to the distal end thereof, the needle communicating with an inner chamber defined by the needle body for reception of fluids through the needle and the sheath is automatically and simultaneously locked in the second distal position when advanced thereby by the user. The needle body includes a plunger assembly therein for drawing fluids into and discharging fluids out of the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described hereinbelow with reference to the drawings wherein:
FIG. 1 is a side view of the safety syringe constructed according to the present invention with the safety sheath in the distal position protecting the needle from unintended contact;
FIG. 2 is a top view of the safety syringe shown in FIG. 1;
FIG. 3 is a side view of the syringe shown in FIG. 1 with the safety sheath released and partially withdrawn to expose the needle;
FIG. 4 is a top view of the syringe shown in FIG. 3;
FIG. 5 is a side view of the safety syringe shown in FIG. 3 with the safety sheath in position in the fully withdrawn position to permit the syringe to be used normally;
FIG. 6 is top view of the safety syringe shown in FIG. 5;
FIG. 7 is a perspective view with parts removed, illustrating schematically, one side of the body of the syringe constructed according to the present invention and the locking system for the safety syringe;
FIG. 8 is a greatly enlarged cross-sectional view illustrating the sheath safety locking mechanism as the safety sheath is being moved distally after using the syringe;
FIG. 9 is a greatly enlarged cross-sectional view of the safety locking mechanism shown in FIG. 8 just prior to locking the safety sheath in the protective position over the needle;
FIG. 10 is a greatly enlarged cross-sectional view of the safety locking mechanism shown in FIGS. 8 and 9 when the safety sheath has been moved distally to the needle protective distalmost position preventing further needle use;
FIG. 11 is a top view of the needle body with major portions removed, illustrating the relative positions of the slots in the needle body on one side which are associated with the safety locking system;
FIG. 12 is a side elevational view thereof, illustrating the safety locking system according to the invention with the relative positions between the safety sheath and the needle body shown in the initial position corresponding to FIG. 1;
FIG. 13 is a side cross-sectional view thereof, illustrating the relative positions of the safety sheath and needle body after the safety sheath has been partially withdrawn;
FIG. 14 is a side cross-sectional view thereof, illustrating the relative positions of the safety sheath and needle body in position for use of the syringe either as an injecting or a fluid aspirating syringe;
FIG. 15 is a side cross-sectional view thereof illustrating the relative positions of the safety sheath and needle body shown in FIG. 14 after use, with the safety sheath pushed distally to a position just prior to engagement of the safety locking system; and
FIG. 16 is a side cross-sectional view thereof illustrating the needle body and the safety sheath with the safety sheath just distally of the position shown in FIGS. 1 and 2.
FIG. 17 is a proximal end view of the safety syringe shown in FIG. 5 with the rear wall and thumb ring removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description which follows "distal" means away from the user and "proximal" means toward the user.
Referring initially to FIG. 1 the safety syringe 10 constructed according to the present invention is shown. The syringe may be of the aspirating type or the injecting type. In the former, fluid is drawn from the body. In the latter, medication or other fluid is injected into the body by the needle. In either case, it is important to protect the needle after it has come in contact with the body fluids of the person in order to prevent inadvertent contact thereafter with a person other than the patient.
The safety syringe 10 includes a needle body 12 having a needle 14 at one end communicating with a chamber 16 defined internally of the needle body and shown in dotted lines. The needle is a medical or surgical type having a hollow cylindrical cross section for drawing and expelling liquids with respect to needle body 12. Finger loop 18 is attached to the needle body at a location just proximal of rear wall 20. A plunger 19 is shown schematically in dotted lines in FIGS. 1 and 4 and is connected to finger loop 18 by elongated member 21, also shown schematically.
As shown in FIG. 1, safety sheath 22 includes two finger loops 24, 26 attached to the sheath via relatively thin strips which are preferably formed of resilient material integrally with sheath 22 and which bias the loops inwardly toward the body to the position shown in FIG. 1. Preferably the safety sheath 22 is constructed of a transparent or translucent resilient plastic material and formed as a cylindrical tubular member having resilient strips 28, 30 which are separable from the body of the safety sheath and are attached at the distalmost portion shown at 32. Although the strips are integrally molded, i.e., monolithic with the safety sheath, they are actually separated from the main sheath by molded "cuts" shown at 30a in FIG. 2, which define the strips and permit the strips to be moved manually toward and away from the sheath. Further, as seen in FIGS. 1 and 2, the safety sheath is generally cylindrical and has portions of the cylindrical wall eliminated as shown at 22a to permit viewing of the transparent liquid measure 16 of the needle body. Such plastic materials as polyethylene, polypropylene, or polycarbonates such as LEXAN brand material marketed by General Electric Company, Pittsfield, Mass., are contemplated. As noted, preferably, the sheath and the body are integrally molded as shown from such plastic materials.
The sheath 22 is dimensioned and configured to slide between proximal and distal positions relative to body 16. Four tracks in the form of elongated slots 17 are formed in body 12 and four corresponding pegs 15 extend inwardly from the inner wall of the sheath 22 and are slidably positioned within tracks 17 to retain the relative angular orientation of sheath 22 with respect to body 12. In FIGS. 1 and 2 only two of such tracks 17 are shown. The normal pre-use condition of the syringe is as shown in FIG. 1.
In FIGS. 3 and 4 the body 12 is shown after the safety sheath 22 has been partially withdrawn proximally by the user by placing the index and middle finger into the finger loops 26, 24 and separating the loops as shown to release pegs 42 from peg reception notches 36 shown in FIG. 11. During this motion the user's thumb is positioned within finger loop 18. The safety sheath 22 is withdrawn fully to the proximalmost position shown in FIGS. 5 and 6 when finger loops 24, 26 are permitted to return to their inwardly biased positions. At this time, pegs 42 enter slots 34 and thereby fix the position of the safety sheath 22 relative to the body 12 in the needle exposed condition shown in FIGS. 5 and 6.
The system for releasably retaining the safety sheath 22 in the pre-use condition and the final safety locking system will now be described in connection with FIGS. 7, 8 and 11-16. In connection therewith for convenience of illustration in FIGS. 11-16 the locking system associated with one finger ring 24 will be described. In FIG. 7, the finger rings 26 and 24 and the remaining portions of the needle body 12 and sheath 22 have been removed for illustration purposes. As constructed, the locking system for the other finger ring 26 is identical but opposite in configuration and position to the system associated with the finger ring 24.
Body 12 includes a series of slots 34, 36, 38, 40 as shown in FIG. 11. Beneath finger ring 24 is positioned peg 42 adapted to enter into either of slots 34, 36 or 38 to establish the position of the safety sheath 22 relative to the body 12. Third, or locking peg 44 is positioned on the internal wall of the sheath 22 and is configured to enter the distal slot 40 of the needle body. Locking peg 44 is attached to strip 43 which is cut out of the safety sheath 22 such that the peg 44 is resiliently biased toward the body 12 by the inward bias of strips 28, 30. This bias is due to the natural resilience of the plastic material forming the sheath 22 from which the sheath 22 and strips 28, 30 are integrally molded. Just proximal of the distal slot 40 is a ramped member 46 for slidable contact by locking peg 44 and reception of peg 44 into slot 40 to lock and fix the position of the sheath in the distalmost, or needle protective position.
In operation, the safety syringe functions as follows. The syringe is delivered to the user in the configuration shown in FIG. 1 with the safety sheath 22 in the distal position corresponding to peg 44 being positioned as shown in FIG. 12 while peg 42 immediately beneath ring 24 being positioned within slot 36. Distal or proximal movement of sheath 22 is thus prevented by the position of peg 42 within slot 36.
To retract the sheath the user positions the thumb within finger loop 18 and the index and middle fingers respectively in one of the aspirating loops 24, 26 as described previously. Thereafter, the index finger and middle finger are separated in opposite directions to release pegs 42 from slots 36 as shown in FIGS. 3, 4 and 13. The finger motion which releases the pegs is opposite the inward natural resilient force provided by strips 28, 30 as shown in FIG. 3, which are formed out of sheath 22 and are resiliently biased toward the body 12. The configuration of body 12 is shown clearly in FIG. 7. The side not shown is the same. As will be observed from the drawings, after the pegs 42 are released the sheath is now free to travel in a proximal direction to expose the needle.
Upon withdrawing the sheath proximally to the position shown in FIG. 14 finger loops 24, 26 are returned to the normal inward positions and pegs 42 re-enter the rearwardly positioned slots 34 thereby fixing the position of sheath 22 with respect to body 12 and exposing needle 14 for use. At this point, the needle may be inserted into the patient's body and the thumb ring 18 may be withdrawn to withdraw the internal plunger assembly 19 of the needle body for normal use of the syringe as an aspirating device, i.e. to draw fluid from the body. Alternatively, this motion may be used to draw fluid from a separate source--such as medication vial--for injection into the body as shown in FIG. 12. When the syringe is in the normal use condition with pegs 42 within slots 34, the distal locking pegs 44 are in a position just distal of slot 38 as shown in FIG. 14.
After normal use of the syringe the aspirating finger loops 24, 26 are once again separated laterally by the index and middle fingers to release pegs 42 from the proximal slots 34 freeing the sheath for distal movement to a distal position covering needle 14 and corresponding to the position of peg 44 within slot 40 as shown in FIG. 10. During this movement, peg 44, which is ramped oppositely-- and preferably approximately parallel--to ramp 46 as shown, slides over ramp surface 47 of ramp 46 and drops into slots 40 under the natural inward resilient bias provided by the resilient material of strip 43. Resilient strips 43 are preferably integrally molded with sheath 22 similarly to strips 28, 30. They are essentially separated from sheath 22 by cuts 43a and in the same manner as strips 28, 30 to bias pegs 44 inwardly toward body 12. When the pegs 44 are positioned within slots 40 the proximal pegs 42 will be positioned within slots 38, the positions of which are just distal of the initial slots 36. As noted, since the pegs 44 are also positioned within slots 40 which are located just distally of the initial position of pegs 44 shown in FIG. 12, the distal position of sheath 22 will be fixed relative to the body 12.
It will be appreciated from the view shown in FIGS. 10 and 16 of the pegs 44 within slots 40 that the configuration of the pegs 44 are such that sheath 22 is locked into a distal needle protective position just slightly distal of the initial position shown in FIG. 1. The resilient action of the material of the strips 43 which cause pegs 44 to become locked within slots 40 render the sheath 22 immovable under normal use by the user. Withdrawal of safety sheath 22 from this locked position is virtually impossible forcing pegs 44 outwardly of slots 40 against the inward resilient force of strips 43. In any event, normal user motions will not release the safety sheath. Thus, the needle is protected by the position of the sheath and inadvertent contact with the known user or other party is virtually impossible without forcing the pegs 44 out of slots 40 or physically destroying the safety sheath 22.
Other variations of the present invention will become evident to persons skilled in the art within the scope of the claims appended hereto.
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A syringe is disclosed which includes a needle body having a proximal end and a distal end, a needle attached to the distal end of the needle body, a plunger for drawing fluid into the needle body through the needle, and a protective sheath configured and dimensioned to be positioned about the needle body and movable between a first distal position whereby the needle is shielded by the sheath and a proximal position whereby the needle is exposed. A system of slots and pegs is provided to releasably retain the protective sheath in the first distal position and to releasably retain the protective sheath in the proximal position. Also a system to retain and lock the protective sheath in a second distal position after use whereby the needle is protected by the sheath. A method of using the safety syringe to protect the needle from inadvertent contact with the user or any person in the area of use is also disclosed.
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This is a divisional application of our pending application having Ser. No. 328,340, filed Dec. 7, 1981, now U.S. Pat. No. 4,459,237.
BACKGROUND
This invention relates to novel compounds and their use in flotation processes for recovering minerals from their ores. In another aspect of the invention it relates to the recovery of molybdenum-bearing minerals from their ores. In another aspect of the invention it relates to the use of flotation agents and flotation depressants in the recovery of minerals from their ores.
Froth flotation is a process for concentrating minerals from ores. In a froth flotation process, the ore is crushed and wet ground to obtain a pulp. Additives such as collecting, or mineral flotation agents and frothing agents are added to the pulp to assist in subsequent flotation steps in separating valuable minerals from the undesired portions of the ore. The pulp is then aerated to produce a froth at the surface. The minerals which adhere to the bubbles or froth are skimmed or otherwise removed and the mineral-bearing froth is collected and further processed to obtain the desired minerals. Frequently, other chemicals are added to the separated mineral-bearing froth to assist in subsequent separations particularly when significant proportions of two or more minerals are present in the separated mineral-bearing froth. Such chemicals are known as depressants. These materials are sometimes referred to more appropriately as deactivators and are used selectively to separate one type of mineral from another type of mineral.
THE INVENTION
The invention deals with a group of novel compounds and their use, alone or in combination with other substances, as reagents in ore flotation processes. One embodiment deals with a process in which a metallurgical concentrate containing molybdenum-bearing compounds is admixed in a froth flotation process with an amount of one or more substituted salts of organo-trithiocarbonates sufficient to depress the flotation of the copper- and iron-bearing materials.
OBJECTS OF THE INVENTION
It is one object of the invention to provide a class of compounds which are useful as flotation suppressants in ore flotation processes.
It is another object to provide a process for the recovery of molybdenum-containing substances from ores containing mixtures of molybdenum-bearing minerals and minerals bearing other metals via a froth flotation procedure in which the flotation of copper and iron are suppressed by contacting the ore with the compounds used herein.
It is still another object of this invention to provide ore separation processes employing both flotation agents and flotation depressants.
Other aspects and objects of this invention will become apparent upon reading this specification and the appended claims.
ADVANTAGES OF THE INVENTION
Unlike commercial suppressants, such as NaCN, NaSH, thioglycolic acid and Nokes solution (i.e., P 2 S 5 /NaOH), the suppressant reagents used herein do not release hazardous gases, such as cyanides and hydrogen sulfide, into the atmosphere.
Furthermore, the compounds used in the invention can be used in smaller quantities than the quantities required for the efficient use of conventional suppressants.
In one embodiment of the invention in an ore flotation process employing collector reagents for the separation of molybdenum, an improvement is made by employing carboxyalkyl trithiocarbonates as suppressants of pyrite and copper. Carboxymethyl trithiocarbonate permits an 84 percent recovery of Mo with a recovery of only 3 percent Fe and 30 percent Cu. When a commercial suppressant blend of NaCN and Nokes solution is used instead of the carboxymethyl trithiocarbonate the Mo recovery is 85.5 percent but the Fe recovery is 5.2 percent and the Cu recovery is 68.3 percent.
DESCRIPTION OF THE INVENTION
The novel compounds used as separation reagents herein are ammonium, Group IA, or Group IIA metal salts of substituted hydrocarbyl trithiocarbonates. They conform to the general formula: ##STR1## wherein X is selected from --OH, --COOH, and --COOY; R is a C 1-20 organic moiety; and Y is a Group IA or IIA metal ion or an ammonium ion. Generally, they are salts of carboxy-substituted organo trithiocarbonates.
A preferred group of compounds are the salts of carboxyalkyltrithiocarbonates conforming to the formula: ##STR2## where X' is selected from --H, and --Y and R and Y have the meanings given above. These salts can be prepared by well-known techniques. One technique is represented by the equation ##STR3## wherein X', R and Y have the designations recited above.
In Formula (II) above, it is preferred that X' be such that a --COOM substituent in which M is lithium, sodium, potassium, calcium, or magnesium is present on the organic moiety. It is highly preferred that M is sodium.
The organic moiety, R, in the reagents of the invention can be any organic moiety which contains from 1 to about 20 carbon atoms and serves to link X-- with the --SCSSY groups. Typically, R is a hydrocarbylene moiety. Useful moieties include alkylene linkages, such as methylene, ethylene, and tertiary butylene groups, and aromatic linkages, such as phenylene, methyl phenylene, methylene phenylene, phenylene methylene, and naphthylene. While it is preferred that R is an unsubstituted hydrocarbylene moiety, R may carry other substituents which do not interfere with the function of the reagents as suppressants in froth flotation processes. Preferably, R is an alkylene group containing from 1 to about 12 carbon atoms.
At least one Y substituent is attached to the terminal sulfur atom of the trithiocarbonate. While Y may be an --NH 4 ion or any Group IA or Group IIA metal ion, it is preferred that Y be a Group IA metal ion. Sodium is highly preferred.
One preferred group of separation reagents used herein are compounds in which X' and Y are identical. Exemplary of such compounds are disalts such as:
S-ammonium-0-ammonium-3-carboxypropyl trithiocarbonate,
S-ammonium-0-ammonium-4-carboxyphenyl trithiocarbonate,
S-sodium-0-sodium carboxymethyl trithiocarbonate,
S-sodium-0-sodium-2-carboxymethyl trithiocarbonate,
S-sodium-0-sodium-3-carboxypropyl trithiocarbonate,
S-sodium-0-sodium-6-carboxyhexyl trithiocarbonate,
S-sodium-0-sodium-2-carboxydodecyl trithiocarbonate,
S-sodium-0-sodium-4-carboxyphenyl trithiocarbonate,
S-sodium-0-sodium-2-carboxy-2-methyl-2-butylethyl trithiocarbonate
S-sodium-0-sodium-p-carboxybenzyl trithiocarbonate
S-sodium-0-sodium-m-carboxymethylphenyl trithiocarbonate and the like, and mixtures thereof.
Mixtures of any of the reagents described by Formula I as well as mixtures of these with other conventional separtion reagents are useful in this invention. Flotation or collecting agents useful in this invention can be chosen from any of the known operable compounds among which are xanthates, dithiophosphates, dithiocarbamates, thiols (mercaptans), thiocarbanilide, fatty acid soaps, arenesulfonates or alkylarenesulfonates, alkyl sulfates, primary amines, quaternary ammonium salts, alkylpyridinium salts, and aromatic and naphthenic oils. The preferred flotation agents are the aromatic oils and naphthenic oils like vapor oil.
The amount of flotation agent employed varies considerably depending on the type of flotation agent employed, the pH, and the type of mineral being floated (sulfide, oxide, etc.). For sulfide mineral flotation, generally only about 0.01 to about 0.1 pound of collector is required per ton of ore.
The amount of carboxyorganotrithiocarbonate salt employed as a suupressant for one or more minerals can vary widely. Generally, the quantity used depends on the amount of flotation or collecting agent employed, the flotation technique used, and on the amount and kinds of minerals present in the ore. When molybdenum is in high concentration (i.e., the primary ore body), the range of trithiocarbonate used can be from about 0.01 to 0.1 pound per ton of ore used. When the molybdenum is in low concentration (i.e., a primary Cu ore body), the range of trithiocarbonate used can be from about 0.1 to 5 pounds per ton of concentrate. In one preferred embodiment of the instant invention, carboxyalkyl trithiocarbonates are used to suppress the flotation of Cu, Fe and "insols" (Ca and Mg silicates) in the presence of molybdenum.
The molybdenum-bearing minerals found in these ores include such substances as molybdenite, MoS 2 , and wulfenite PdMoO 4 . These and other molybdenum-containing materials can be isolated from the minerals-containing froth while the flotation of the less desirable minerals is suppressed by the reagents of the invention.
Any froth flotation apparatus can be used in this invention. The most commonly used commercial flotation machines are the Agitair (Galigher Co.), Denver D-2 (Denver Equipment Co.), and the Fagergren (Western Machinery Co.). Smaller, laboratory scale apparatus such as the Halimond cell can also be used.
The instant invention was demonstrated in tests conducted at ambient room temperature and atmospheric pressure. However, any temperature or pressure generally employed by those skilled in the art is within the scope of this invention.
EXAMPLES
The following examples serve to illustrate the operability of this invention.
EXAMPLE I
This example describes the preparation of the hydroxy- and carboxyalkyl trithiocarbonates described herein. This procedure is typical for all compounds prepared. To a 3-neck glass flask fitted with a condenser, stirrer, thermometer and dropping funnel was added 180 milliliters of water and 42 grams (1.05 moles) of sodium hydroxide. After cooling to below 50° C., 53 grams (0.5 moles) of 3-mercaptopropionic acid was slowly added with stirring over a 20 minute period. The mixture was cooled to below 45° C. whereupon 38 grams (0.5 mole) of carbon disulfide was slowly added over a 30 minute period. The cloudy mixture was maintained with stirring at 45° C. for 1.5 hours at which time the solution became clear. The bright orange clear solution was cooled to room temperature and bottled. The solution was calculated to be 40 weight percent of the disodium salt of 2-carboxyethyl trithiocarbonic acid referred to herein also as S-sodium-0-sodium-2-carboxyethyl trithiocarbonate.
There was similarly prepared a 40 weight percent aqueous solution of the disodium salt of carboxymethyl trithiocarbonic acid from 42 grams (1.05 moles) of sodium hydroxide, 144 milliliters of water, 46 grams (0.5 mole) thioglycolic acid and 38 grams (0.5 mole) of carbon disulfide. Likewise there was prepared a 40 weight percent aqueous solution of the monosodium salt of 2-hydroxyethyl trithiocarbonic acid from 22 grams (0.55 mole) sodium hydroxide, about 140 milliliters water, 39 grams (0.5 mole) 2-hydroxyethyl mercaptan and 38 grams (0.5 mole) carbon disulfide.
EXAMPLE II
This example described an alternate method of preparing the S-sodium-0-sodium of carboxymethyl trithiocarbonate which may offer economical advantages over the method of Example I. To a 300 milliliter capacity stainless steel stirred reactor was added 30 grams of water and 20 grams (0.5 mole) sodium hydroxide. The reactor was closed and hydrogen sulfide (16 grams, 0.47 mole) was slowly pressured into the reactor over about a 20 minute period. Cooling was applied through cooling coils to maintain the temperature below 38° C. The pressure on the reactor was 70 psig. Carbon disulfide (19 grams, 0.25 mole) was slowly added with cooling and stirring over a 50 minute period, the temperature being about 28° C. and the pressure 60 to 75 psig. A solution comprised of 58 milliliters water, 10 grams (0.25 mole) sodium hydroxide and 23.5 grams (0.25 mole) of chloroacetic acid was pumped into the reactor over a 30 minute period while maintaining the temperature below 35° C. The pressure on the reactor slowly rose to 145 psig by the end of the addition. After the addition was complete, the mixture was heated to 50° C. for 1 hour with stirring, cooled to about 25° C. and discharged to give 146 grams of effluent product calculated to be about 40 weight percent aqueous solution of disodiocarboxymethyl trithiocarbonate (includes the trithiocarbonate, water, and sodium chloride).
EXAMPLE III
This example is a control describing a standard ore flotation process with and without a copper and iron suppressant (e.g., Nokes Reagent). The example describes the procedure used herein to evaluate the mining chemicals. To a ball mill was charged 1005 grams of primary molybdenum-containing ore from Amax Mines, Climax, Col., along with 0.3 gram lime, 500 milliliters water, pine oil (0.027 lb/ton ore), Syntex (0.05 lb/ton ore), a sulfonated coconut oil from Colgate-Palmolive, vapor oil (0.38 lb/ton ore), sodium silicate (0.66 lb/ton ore), and Nokes reagent (0.03 lb/ton ore), aqueous P 2 S 5 /NaOH to suppress copper and iron flotation. The mixture was ground for 4 minutes, 8 seconds to give a particle size distribution of 35 percent +100 Tyler mesh screen size. The mixture was transferred to a Denver D-12 flotation cell along with enough water to make a 20 weight percent aqueous solids mixture. An additional 0.03 lb/ton ore of Nokes solution was added and the mixture was conditioned for 2 minutes while being stirred at 1000 RPM. Air was introduced into the pulp through the agitator at 42.5 cubic feet per minute. The concentrate was scraped off with a paddle at about 25 strokes per minute for a float of 5 minutes. After flotation, the concentrate was dried and analyzed. The procedure was repeated several times. In the first repeat, Nokes solution was omitted. In the second repeat, thiodiglycol (2,2'-thiodiethanol) was substituted for the Nokes solution and in the third repeat, disodium carboxymethyl trithiocarbonate (supplied as a 40 weight percent aqueous solution) was substituted for the Nokes solution. These results which are listed in Table I show the disodium carboxymethyl trithiocarbonate greatly reduces the amount of iron and copper floated as compared to the other systems employed while maintaining a higher but at least comparable amount of molybdenum recovery.
TABLE I______________________________________Suppresion of Fe and Cu in a Mo-Bearing Ore Flotation Process Rougher ConcentrateSuppressant (.03 lb/ton Grams % in Concentratein Grind and Cell) Fe Cu Mo Fe Cu Mo______________________________________Control - No suppressor 0.926 .083 1.57 4.03 .36 6.81Nokes - P.sub.2 S.sub.5 /NaOH 1.530 .038 1.63 5.23 .13 5.59Thiodiglycol 1.490 .087 1.68 5.13 .30 5.74S--Sodium-O--Sodium 0.490 .012 1.45 2.75 .07 8.16CarboxymethylTrithiocarbonate______________________________________
EXAMPLE IV
This example contains inventive runs illustrating the effect of carboxyalkyl trithiocarbonate salts as suppressants (or collectors) on the separation of iron, copper and molybdenum by flotation. The general procedure described in Example III was followed but with a few minor changes. For example, to the grind was added 1005 grams of ore, 497 milliliters of water, lime (0.2 lb/ton ore), pine oil (0.037-0.052 lb/ton ore), Syntex (0.05 lb/ton ore), sodium silicate (0.66 lb/ton ore), and vapor oil (0.38 lb/ton ore). There were 3 floats made for each run. The suppressant (or collector) at 0.04 lb/ton ore was added before the first float. Before each of the second and third floats was added additional Syntex (0.02 lb/ton ore) and 0.16 lb/ton ore of vapor oil. Each float was 2 minutes. When Nokes reagent (0.03 lb/ton ore) was used, it was added at the grind stage. The results of these runs are listed in Table II wherein it can be seen that the carboxyalkyl trithiocarbonate salts suppress the flotation of iron and especially copper significantly better than does a commercially available copper and iron suppressant, Nokes reagent. The data also shows that 2-hydroxyethyl trithiocarbonate salt, an analog to the inventive carboxyalkyl trithiocarbonates, does not suppress copper or iron. In fact, the data seems to indicate the hydroxyalkyl trithiocarbonate actually enhances the flotation of iron. In addition, the data indicates the carboxyalkyl trithiocarbonates perform better as iron suppressants in the absence of Nokes reagent. Also, the data indicates the carboxyethyl trithiocarbonate is a better Cu suppressant than the carboxymethyl trithiocarbonate, whereas the carboxymethyl trithiocarbonate is a better Fe suppressant than the carboxyethyltrithiocarbonate.
TABLE II______________________________________Suppression of Fe and Cu in a Mo-Bearing Ore Flotation ProcessNokes.sup.a % RecoveryNo. #/Ton Suppressant, 0.04 lb/Ton Ore Fe Cu Mo______________________________________1 .03 None-Control 5.15 68.30 85.502 -- None-Control 7.70 65.10 79.003 .03 S--Sodium-2-Hydroxyethyl 22.20 63.90 84.60 trithiocarbonate4 .03 S--Sodium-O-- Sodium-2- 4.24 24.49 80.49 Carboxyethyl trithiocarbonate5 -- S--Sodium-O--Sodium-2- 3.44 21.91 75.48 Carboxyethyl trithiocarbonate6 .03 S--Sodium-O--Sodium- 3.16 28.03 83.19 Carboxymethyl trithio- carbonate7 -- S--Sodium-O--Sodium- 2.76 30.08 84.19 Carboxmethyl trithio- carbonate______________________________________ .sup.a Nokes reagent is aqueous P.sub.2 S.sub.5 and NaOH.
Reasonable variations, such as would occur to one of ordinary skill in the art, may be made herein without departing from the scope of the invention.
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The efficiency of metals separation using ore flotation is improved by the use of certain substituted hydrocarbylene trithiocarbonates as suppressants for undesired metals.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. Ser. No. 11/389,056, filed Mar. 27, 2006, which is continuation application of U.S. Ser. No. 10/684,210, filed Oct. 10, 2003 (now U.S. Pat. No. 7,093,087) and is related to U.S. Ser. No. 11/180,378, filed Jul. 12, 2005 (now U.S. Pat. No. 7,089,386). The present application claims priority upon Japanese Patent Application No. 2002-366374 filed on Dec. 18, 2002, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for controlling a storage device controller, a storage device controller, and a program.
[0004] 2. Description of the Related Arts
[0005] There is a well-known copy management function used in a storage system that includes an information processing apparatus and a disk array unit connected to each other for communications. The function manages primary volume data in duplicate by copying data from a primary volume to a secondary volume in real time. The primary (master) volume that is a source of copy and the secondary (sub) volume that is a destination of copy are paired.
[0006] In such a storage system, however, data often overflows one primary volume into other primary volumes during communications between the information processing apparatus and the disk array unit. If an attempt is made to back up the data in such an occasion, a plurality of pairs (of primary and secondary volumes) must be reset from the paired state. If data in a primary volume for which the pair is already reset is updated during sequential resetting of paired states, the data is not updated in its corresponding secondary volume while data in a primary volume of which pair state is not reset is updated in its corresponding secondary volume sometimes.
SUMMARY OF THE INVENTION
[0007] Under such circumstances, it is an object of the present invention to provide a method for controlling a storage device controller, a storage device controller, and a program capable of managing copies of data while keeping the consistency among the data stored in a plurality of storage volumes.
[0008] One aspect of the present invention resides in the storage device controlling method that controls the storage device controller connected to a storage device provided with a plurality of storage volumes for storing data and an information processing apparatus for requesting the input/output of the data and used to input/output the data to/from the storage volumes. The method comprises a step of bringing one (source) of the storage volumes into correspondence with another (destination) in which a copy of data is to be written when the data is written in the source storage volume so as to form a pair group consisting of a plurality of such source and destination storage volumes; a step of resetting the correspondence between source and destination storage volumes of each pair in the pair group; a step of deciding whether or not it is after the correspondence is reset that an input/output request has been issued from the information processing apparatus; and a step of inputting/outputting data after the correspondence is reset when it is after the correspondence is reset that the input/output request has been issued from the information processing apparatus.
[0009] The storage device and the storage device controller are included in the disk array unit. The information processing apparatus and the disk array unit are included in the storage system.
[0010] Storage volumes are storage resources provided in the disk array unit or storage device and they are divided into physical volumes and logical volumes. A physical volume is a physical storage area provided in a disk drive of the disk array unit or storage device and a logical volume is a storage area allocated logically in a physical volume.
[0011] The “paired” means a state in which two storage volumes are brought into correspondence with each other as described above.
[0012] That is why the present invention can provide a method for controlling a storage device controller, a storage device controller, and a program capable of managing copies of data while keeping the consistency among data stored in a plurality of storage volumes as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Preferred embodiments of the present invention will now be described in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is an overall block diagram of a storage system in an embodiment of the present invention;
[0015] FIG. 2 is a block diagram of an information processing apparatus in the embodiment of the present invention;
[0016] FIG. 3 is a block diagram of a channel adapter provided in a storage device controller in the embodiment of the present invention;
[0017] FIG. 4 is a table stored in a shared storage provided in the storage device controller in the embodiment of the present invention;
[0018] FIG. 5 is pairs of storage volumes in the embodiment of the present invention;
[0019] FIG. 6 is a flowchart of the processings of the storage device controller for splitting a pair in the embodiment of the present invention;
[0020] FIG. 7 is a flowchart of the processings of the storage device controller for splitting a pair and inputting/outputting the split pair data items in the embodiment of the present invention;
[0021] FIG. 8 is a table stored in the shared storage provided in the storage device controller in the embodiment of the present invention; and
[0022] FIG. 9 is a flowchart of the processings of the storage device controller for splitting a pair.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Hereunder, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0000] ===Overall Configuration===
[0024] At first, the storage system in an embodiment of the present invention will be described with reference to the block diagram shown in FIG. 1 .
[0025] An information processing apparatus 100 is a computer provided with a CPU (Central Processing Unit), a memory, etc. The CPU of the information processing apparatus 100 executes various types of programs to realize various functions of the apparatus 100 . The information processing apparatus 100 is used, for example, as a core computer in an automatic teller machine in a bank, a flight ticket reservation system, or the like.
[0026] The information processing apparatus 100 is connected to a storage device controller 200 to communicate with the controller 200 . The information processing apparatus 100 issues data input/output commands (requests) to the storage device controller 200 to read/write data from/to the storage devices 300 . The information processing apparatus 100 also sends/receives various commands to/from the storage device controller 200 to manage the storage devices 300 . For example, the commands are used for managing copies of data stored in the storage volumes provided in the storage devices 300 .
[0027] FIG. 2 shows a block diagram of the information processing apparatus 100 .
[0028] The information processing apparatus 100 is configured by a CPU 110 , a memory 120 , a port 130 , a media reader 140 , an input device 150 , and an output device 160 .
[0029] The CPU 110 controls the whole information processing apparatus 100 and executes the programs stored in the memory 120 to realize various functions of the apparatus 100 . The media reader 140 reads programs and data recorded on the recording medium 170 . The memory 120 stores the programs and data read by the reader 140 . Consequently, the media reader 170 can be used to read a storage device management program 121 and an application program 122 recorded in the medium 170 and store them in the memory 120 . The recording medium 170 may be any of flexible disks, CD-ROM disks, semiconductor memories, etc. The media reader 140 may also be built in the information processing apparatus 100 or provided as an external device. The input device 150 is used by the operator to input data addressed to the information processing apparatus 100 . The input device 150 may be any of keyboards, mice, etc. The output device 160 outputs information to external. The output device 160 may be any of displays, printers, etc. The port 130 is used to communicate with the storage device controller 200 . In that connection, the storage device management program 121 and the application program 122 may be received from another information processing apparatus 100 through the port 130 and stored in the memory 120 .
[0030] The storage device management program 121 manages copies of data stored in the storage volumes provided in the storage devices 300 . The storage device controller 200 manages copies of data with use of various copy management commands received from the information processing apparatus 100 .
[0031] The application program 122 realizes the functions of the information processing apparatus 100 . For example, the program 122 realizes functions of an automatic teller machine of a bank and functions of a flight ticket reservation system as described above.
[0032] Next, the storage device controller 200 will be described with reference to FIG. 1 again. The storage device controller 200 controls the storage devices 300 according to the commands received from the information processing apparatus 100 . For example, when receiving a data input/output request from the information processing apparatus 100 , the storage device controller 200 inputs/outputs data to/from a storage volume provided in a storage device 300 .
[0033] The storage device controller 200 is configured by a channel adapter 210 , a cache memory 220 , a shared storage 230 , a disk adapter 240 , a management terminal (SVP: SerVice Processor) 260 , and a connection unit 250 .
[0034] The channel adapter 210 provided with a communication interface with the information processing apparatus 100 exchanges data input/output commands, etc. with the information processing apparatus 100 .
[0035] FIG. 3 shows a block diagram of the channel adapter 210 .
[0036] The channel adapter 210 is configured by a CPU 211 , a cache memory 212 , a control memory 213 , a port 215 , and a bus 216 .
[0037] The CPU 211 controls the whole channel adapter 210 by executing a control program 214 stored in the control memory 213 . The control program 214 stored in the control memory 213 thus enables data copies to be managed in this embodiment. The cache memory 212 stores data, commands, etc. to be exchanged with the information processing apparatus 100 temporarily. The port 215 is a communication interface used for the communication with the information processing apparatus 100 and other devices provided in the storage device controller 200 . The bus 216 enables the mutual connection among those devices.
[0038] Return to FIG. 1 again. The cache memory 220 stores data to be exchanged between the channel adapter 210 and the disk adapter 240 temporarily. In other words, if the channel adapter 210 receives a write command as a data input/output command from the information processing apparatus 100 , the channel adapter 210 writes the command in the shared storage 230 and the target data received from the information processing apparatus 100 in the cache memory 220 respectively. The disk adapter 240 then reads the target data from the cache memory 220 according to the write command written in the shared storage and writes the read data in a storage device 300 .
[0039] The management terminal 260 is a kind of information processing apparatus used for the maintenance/management of the storage device controller 200 and the storage devices 300 . For example, the management terminal 260 changes the control program 214 executed in the channel adapter 210 to another. The management terminal 260 may be built in the storage device controller 200 or may be separated. The management terminal 260 may also be dedicated to the maintenance/management of the storage device controller 200 and the storage devices 300 or may be configured as a general information processing apparatus for maintenance/management. The configuration of the management terminal 260 is the same as that of the information processing apparatus 100 shown in FIG. 2 . Concretely, the management terminal 260 is configured by a CPU 110 , a memory 120 , a port 130 , a recording media reader 140 , an input device 150 , and an output device 160 . Consequently, the control program to be executed in the channel adapter 210 may be read from the recording medium 170 through the media reader 140 of the management terminal 260 or received from the information processing apparatus 100 connected thereto through the port 130 of the management terminal 260 .
[0040] The disk adapter 240 controls the storage devices 300 according to the commands received from the channel adapter 210 .
[0041] Each of the storage devices 300 is provided with a storage volume to be used by the information processing apparatus 100 . Storage volumes are storage resources provided in the storage devices 300 and divided into physical volumes that are physical storage areas provided in disk drives of the storage devices 300 and logical volumes that are storage areas allocated logically in those physical volumes. The disk drives may be any of, for example, hard disk drives, flexible disk drives, semiconductor storage devices, etc. The disk adapter 240 and each of the storage devices 300 may be connected to each other directly as shown in FIG. 1 or through a network. The storage devices 300 may also be united with the storage device controller 200 into one.
[0042] The shared storage 230 can be accessed from both of the channel adapter 210 and the disk adapter 240 . The shared storage is used to receive/send data input/output requests/commands and store management information, etc. of the storage device controller 200 and the storage devices 300 . In this embodiment, the shared storage 230 stores a consistency group management table 231 and a pair management table 232 as shown in FIG. 4 .
[0000] ===Pair Management Table===
[0043] The pair management table 232 is used to manage copies of data stored in the storage devices 300 . The table 232 has columns of “pair”, “primary volume”, “sub volume”, “pair state”, and “consistency group”.
[0044] The “pair” column holds pair names. A pair means a combination of two storage volumes. FIG. 5 shows an example of paired storage volumes. In FIG. 5 , two pairs, that is, pairs A and B are denoted. One of paired volumes and the other of the paired volumes are managed as a primary volume and a secondary volume. In FIG. 5 , a primary volume is described as a master volume and a secondary volume is described as a sub volume. A plurality of secondary volumes can be combined with one primary volume.
[0045] Return to the pair management table 232 shown in FIG. 4 . The “primary” column describes primary volumes paired with secondary volumes while the “secondary” column describes secondary volumes paired with primary volumes.
[0046] The “pair state” column describes the state of each pair of volumes. The “pair state” is classified into “paired”, “split”, and “re-sync”.
[0047] The “paired” denotes that data in a secondary volume is updated with the data in its corresponding primary volume written by the information processing apparatus 100 . The consistency of the data stored in a pair of primary and secondary volumes is assured with such correspondence set between those primary and secondary volumes.
[0048] The “split” denotes that data in a secondary volume is not updated with the data in its corresponding primary volume written by the information processing apparatus 100 . Concretely, while primary and secondary volumes are in such a “split” state, the correspondence between those volumes is reset. Consequently, the data consistency is not assured between those primary and secondary volumes. However, because data in any secondary volume that is in the “split” state is not updated, the data in secondary volumes can be backed up during the while; for example, data stored in secondary volumes can be saved in a magnetic tape or the like. This makes it possible to back up data while the data in primary volumes is used continuously during the backup operation for a job that has been executed by the information processing apparatus 100 .
[0049] The “re-sync” denotes a transition state of a pair of volumes, for example, from “split” to “paired”. More concretely, the “re-sync” means a state in which data in a secondary volume is being updated with the data written in its corresponding primary volume while the pair is in the “split” state. When the data in the secondary volume is updated, the state of the pair is changed to “paired”.
[0050] To form a pair of storage volumes or to change the state of the pair from “paired”/“split” to “split”/“paired”, the operator instructs the information processing apparatus 100 in which the storage device management program 121 is executed through the input device 150 . A command from the operator is then sent to the channel adapter 210 of the storage device controller 200 . After that, the channel adapter 210 executes the control program 214 to form a pair of storage volumes or change the state of the pair according to the command. According to the state of the formed pair of storage volumes, the channel adapter 210 controls the object storage volumes, for example, updating a secondary volume with a copy of data updated in its corresponding primary volume when those volumes are “paired”.
[0051] As described above, the channel adapter 210 changes the states of pairs one by one sequentially. This is because one primary volume can be paired with a plurality of secondary volumes as described above and if the states of a plurality of pairs are changed simultaneously, the management of primary volumes comes to become complicated.
[0052] Forming a pair of volumes and changing the state of each pair of volumes can also be made automatically at a predetermined time or according to a command received from another information processing apparatus 100 connected through the port 130 independently of instructions from the operator.
[0000] ===Consistency Group===
[0053] The “consistency group” column describes the number of each consistency group (pair group) consisting of pairs of volumes. A consistency group means a group of a plurality of storage volume pairs to be controlled so that the states of those pairs are changed to the “split” together. Concretely, a plurality of pairs in a consistency group are controlled so that their states are changed to the “split” simultaneously (hereinafter, this processing will be referred to as the synchronism among the state changes to the “split”) while the states of a plurality of paired volumes are changed one by one sequentially as described above.
[0054] For example, assume now that the information processing apparatus 100 writes data in a storage volume while the pair states of a plurality of paired volumes in a consistency group are changed sequentially from “paired” to “split”. If no consistency group is formed and the data is written in a paired primary volume after the pair state is changed to the “split”, the data is not written in its corresponding secondary volume. If the data is written in a paired primary volume of which state is not changed to the “split” yet, the data is also written in the secondary volume. If the paired primary volume belongs to a consistency group at that time, however, the data is not written in its corresponding secondary volume regardless of the pair state of the primary volume (whether it is in the “split” or not). This is because the data is written in the primary volume after pair splitting (resetting of the correspondence between primary and secondary volumes) is started in the consistency group.
[0055] Forming a consistency group with a plurality of pairs such way is effective for a case in which data is to be stored in a plurality of storage volumes, for example, when write data is too large to be stored in one storage volume and when it is controlled so that one file data is stored in a plurality of storage volumes.
[0056] Such assured synchronism of the pair state changes of volumes to the “split” in a consistency group is also effective for writing/reading of data in/from secondary volumes requested from the information processing apparatus 100 .
[0057] Concretely, if no consistency group is already formed, data can be written/read in/from any paired secondary volume after the pair state is changed to the “split” while it is inhibited to write/read data in/from any secondary volume of which pair state is not changed to the “split”.
[0058] In this embodiment, a batch split receiving flag (ID information) of the consistency group management table 231 is used to assure the synchronism of such pair state changes of volumes to the “split” in the above consistency group. Next, the processings for assuring such synchronism will be described with reference to the flowchart shown in FIG. 6 .
[0000] ===Processing Flow===
[0059] The following processings are executed by the CPU 211 provided in the channel adapter 210 with use of the control program 214 (program) consisting of codes for realizing various operations in this embodiment.
[0060] At first, the channel adapter 210 receives a pair splitting request (split command) addressed to a consistency group from the information processing apparatus 100 (S 1000 ). The channel adapter 210 then turns on the batch split receiving flag in the consistency group management table 231 stored in the shared storage 230 (S 1001 ). After that, the channel adapter 210 begins to change the pair state of a not-split pair of volumes in the consistency group to the “split” (S 1003 ). Concretely, the channel adapter 210 resets the correspondence between the primary volume and the secondary volume in the pair and stops updating of the data in the secondary volume with the data written in the primary volume. The channel adapter 210 then changes the description for the pair in the “paired” column in the pair management table 232 to “split” (S 1004 ). Those processings are repeated for each pair in the consistency group. When the states of all the pairs in the consistency group are changed to the “split” (S 1005 ), the channel adapter 210 turns off the batch split flag, then exits the processing.
[0061] If the channel adapter 210 receives a read/write request from the information processing apparatus 100 during the above processing, the adapter 210 checks whether or not the request is addressed to a not-split storage volume, that is, a “paired” storage volume (for which the correspondence to its secondary volume is not reset)(S 1006 ). If the check result is YES (addressed), the adapter 210 changes the pair state of the volume to the “split” (S 1007 ). The adapter 210 then changes the description of the pair in the pair state column in the pair management table 232 to the “split” (S 1008 ) and executes the data read/write processing (input/output processing)(S 1009 ).
[0062] On the other hand, if the check result in (S 1006 ) is NO (not addressed), this means that the command is addressed to a “split” volume. The adapter 210 thus executes the read/write processing for the storage volume (S 1009 ) immediately.
[0063] Consequently, the synchronism of the pair state changes of “paired” volumes to the “split” in a consistency group is assured.
[0064] In the flowchart shown in FIG. 6 , if the channel adapter 210 receives a read/write request from the information processing apparatus 100 while splitting paired volumes in a consistency group sequentially, the adapter 210 checks whether or not the request is addressed to a not-split pair of volumes (S 1006 ) to execute the read/write processing (S 1009 ). However, it is also possible for the adapter 210 to suppress the execution of the read/write processing requested from the information processing apparatus 100 while the adapter 210 splits paired volumes in a consistency sequentially. In that connection, the adapter 210 can execute the read/write processing after the adapter 210 completes splitting of all the paired volumes in the consistency group and turns off the batch split flag.
[0065] FIG. 7 shows a flowchart for those processings by the channel adapter 210 in detail.
[0066] At first, the channel adapter 210 forms a consistency group for both pairs A and B according to a command received from the information processing apparatus 100 (S 2000 to S 2002 ). The command is inputted, for example, by the operator through the input device 150 of the information processing apparatus 100 . The command inputted to the information processing apparatus 100 is sent to the channel adapter 210 by the storage device management program 121 . The “paircreate −g GRP0” shown in FIG. 7 is such a command. Receiving the command, the channel adapter 210 forms a consistency group, then records predetermined data in the pair management table 232 and the consistency group management table 231 stored in the shared storage 230 respectively. FIG. 4 shows how the predetermined data is recorded in those tables 231 and 232 . However, although the state of the pair A is described as “split” in the pair state column in the pair management table 232 shown in FIG. 4 , the state of the pair A at that time is actually “paired”. Similarly, although “ON” is described in the batch split receiving flag column for the consistency group 0 in the consistency group management table 231 , the actual state at that time is actually “OFF”.
[0067] The channel adapter 210 , when receiving a read/write request (R/W 1 ) for the storage volume 1 in the pair A from the information processing apparatus 100 (S 2008 ), executes the read/write processing as usually (S 2009 ). This is because “OFF” is described in the batch split receiving flag column for the consistency group 0 in the consistency group management table 231 .
[0068] After that, the information processing apparatus 100 instructs the channel adapter 210 to split the pair B in the consistency group 0 with a command (S 2003 ). The “pairsplit −g GRP0” shown in FIG. 7 is an example of the command issued at that time. This command may also be inputted by the operator through the input device 150 of the information processing apparatus 100 .
[0069] The channel adapter 210 then turns on the batch split receiving flag for the consistency group 0 in the consistency group management table 231 stored in the shared storage 230 (S 2004 ) to start splitting of each pair sequentially. (S 2005 , S 2006 ). FIG. 4 shows the pair management table 232 in which the pair A is split. Completing splitting of all the target pairs, the channel adapter 210 turns OFF the batch split receiving flag and exits the processing (S 2007 ).
[0070] If the channel adapter 210 receives a read/write request (R/W 2 ) addressed to the storage volume 3 of the pair B from the information processing apparatus 100 (S 2010 ) while the channel adapter 210 turns ON the batch split receiving flag (S 2004 ) after receiving a split command addressed to the consistency group 0 from the information processing apparatus 100 , the channel adapter 210 executes the read/write processing as usually (S 2011 ). This is because “OFF” is still set in the batch split receiving column for the consistency group 0 in the consistency group management table 231 .
[0071] However, if the channel adapter 210 receives a read/write request (R/W 3 ) addressed to the storage volume 3 of the pair B from the information processing apparatus 100 (S 2012 ) after turning ON the batch split receiving flag (S 2004 ), the channel adapter 210 splits the pair B (S 2013 ), then executes the read/write processing (S 2014 ).
[0072] As described above, the channel adapter 210 , when receiving a read/write request from the information processing apparatus 100 , refers to the batch split receiving flag to check whether or not it is after resetting of the pair state of each pair in the consistency group is started that the read/write command has been issued.
[0073] If the channel adapter 210 receives the read/write request (R/W 4 ) after completing splitting of the pair A in (S 2005 ), the channel adapter 210 executes the read/write processing (S 2016 ). This is because “split” is set for the pair A in the pairing column in the pair management table 232 and the channel adapter 210 knows that “splits” denotes that the pair A is split.
[0074] In that connection, no splitting processing is done for the pair B in (S 2005 ), since the pair B is already split during the read/write processing in (S 2013 ).
[0075] In this embodiment, because the batch split receiving flag is provided as described above, the synchronism among the pair state changes of all the pairs in a consistency group to the “split” is assured.
[0000] ===Consistency Group Management Table===
[0076] Next, a description will be made for another embodiment of the present invention with respect to the management information in the consistency group management table 231 .
[0077] In this embodiment, each split starting time is recorded in the consistency group management table 231 as shown in FIG. 8 . In the example shown in FIG. 8 , splitting of pairs in the consistency group 0 is started at 12:00. When splitting of all the pairs in the consistency group 0 is completed, the description in the split starting time column is changed to “−”.
[0078] A split starting time is specified with a command received from the information processing apparatus 100 . Such split starting may also be specified so as to be started immediately with a command; no concrete time is specified in such an occasion. In that connection, the current time is recorded in the split starting time column.
[0079] In this embodiment, the channel adapter 210 , when receiving a read/write command from the information processing apparatus 100 , compares the read/write command issued time recorded in the read/write command (request) with the time described in the split starting time column of the consistency group management table 231 . If the command issued time is later, the channel adapter 210 executes the read/write processing after the end of the splitting.
[0080] This is why it is possible to assure the synchronism among the state changes of pairs in a consistency group to the “split”.
[0000] ===Processing Flow===
[0081] Next, how the above processings are executed will be described in detail with reference to the flowchart shown in FIG. 9 .
[0082] The processings are executed by the CPU 211 of the channel adapter 210 with use of the control program 214 consisting of codes for realizing various operations in this embodiment.
[0083] At first, the channel adapter 210 receives a pair splitting request (split command) addressed to a consistency group from the information processing apparatus 100 (S 3000 ). The channel adapter 210 then records the split starting time recorded in the split command in the split starting time column of the consistency group management table 231 stored in the shared storage 230 (S 3001 ). After that, the channel adapter 210 compares the split starting time with the current time to check whether or not the split starting time is passed (S 3003 ). If the check result is YES (passed), the channel adapter 210 begins the state change of a not-split pair in the consistency group to the “split” (S 3004 ). Concretely, the channel adapter 210 resets the correspondence between primary and secondary volumes of the pair and suppresses updating of the data in the secondary volume with the data written in the primary volume. The channel adapter 210 then changes the description for the pair in the pair state column in the pair management table 232 to “split” (S 3005 ). The above processings are repeated for all of the pairs in the consistency group. When the states of all the pairs in the consistency group are changed to “split” (S 3006 ), the channel adapter 210 changes the description for the pair in the split starting time column to “−” and exits the processing (S 3007 ).
[0084] If the channel adapter 210 receives a read/write request from the information processing apparatus 100 during the above processing, the channel adapter 210 checks whether or not the request is addressed to a not-split pair, that is, a “paired” storage volume (the correspondence is not reset)(S 3008 ). If the check result is YES (addressed), the channel adapter 210 compares the command issued time recorded in the command with the split starting time (S 3010 ). If the command issued time is later, the channel adapter 210 changes the pair state to the “split” (S 3011 ), then changes the description for the pair in the pair state column in the pair management table 232 to “split” (S 3012 ). After that, the channel adapter 210 executes the read/write processing (input/output processing) (S 3013 ).
[0085] On the other hand, if the read/write command is addressed to a split pair in (S 3008 ), that is, a “split” storage volume or the command issued time recorded in the request is earlier than the split starting time, the channel adapter 210 reads/writes data from/in the storage volume (S 3009 ).
[0086] This is why it is possible to assure the synchronism among the state changes of the pairs in a consistency group to the “split”.
[0087] In the flowchart shown in FIG. 9 , if the channel adapter 210 receives a read/write request from the information processing apparatus 100 while splitting pairs in a consistency group sequentially, the channel adapter 210 checks whether or not the request is addressed to a not-split storage volume (S 3008 ) and executes the read/write processing (S 3009 , S 3013 ). However, the channel adapter 210 can also suppress execution of the read/write processing even when receiving a read/write request from the information processing apparatus 100 while splitting pairs in a consistency group sequentially as described above. In that occasion, the channel adapter 210 executes the read/write processing after completing splitting of all the pairs in the consistency group and changing the description for the pair in the split starting time column to “−”.
[0088] In this embodiment, consistency groups are formed by storage devices 300 connected to the same storage device controller respectively. However, the present invention is not limited only to that embodiment. In this embodiment, consistency groups should preferably be formed by storage devices 300 connected to a plurality of storage device controllers respectively. In that connection, a consistency group may be formed over a plurality of storage device controllers 200 that come to communicate with each another to create the consistency group management table 231 and the pair management table 232 . The consistency group management table 231 and the pair management table 232 may be managed by one of the storage device controllers 200 and shared with other storage device controllers 200 or each of those storage device controllers manages the same table. Furthermore, volumes controlled by a plurality of storage device controllers 200 should preferably be paired in this embodiment. In that connection, a pair might be formed over a plurality of storage device controllers 200 and those storage device controllers 200 come to communicate with each another to create the consistency group management table 231 and the pair management table 232 . In that connection, the consistency group management table 231 and the pair management table 232 may be managed by one of the storage device controllers 200 and shared with other storage device controllers 200 or those storage device controllers manages the same table respectively.
[0089] While the embodiments of the present invention have been described, the description is just for illustrative purposes, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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Disclosed herein is a method for controlling a storage device controller connected to a storage device provided with a plurality of storage volumes for storing data respectively and an information processing apparatus for requesting an input/output of data so as to receive an input/output request from the information processing apparatus and execute an input/output processing of the data for each of the plurality of storage volumes. The method brings one (primary) of the plurality of storage volumes into correspondence with another (secondary) in which a copy of data is to be written when the data is written in the primary volume so as to form a pair group consisting of a plurality of pairs, each having such a primary volume and such a secondary volume. Upon receiving an input/output request from the information processing apparatus, the method starts resetting of the correspondence between storage volumes of each pair included in the pair group to decide whether or not it is after resetting of the correspondence is started that the request has been issued and executes an input/output processing after resetting the correspondence if the request is issued after resetting of the correspondence is started.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent application Ser. No. 61/466,329, filed Mar. 22, 2011 by the present inventor.
BACKGROUND
The impact of environmental and climate change, coupled with high oil prices, fossil fuel resources and energy regulations are driving the development of renewable energy. The present invention is based on thermal gradient energy conversion for the generation of hydroelectric power.
As the oceans cover a little more than 70 percent of the Earth's surface it makes the sea the largest solar energy collector on the planet and is ideally suited for the present invention. When the difference between the warm surface water and the cold deep water is above 18 degrees Celsius, a thermal energy conversion system becomes viable as it utilizes this natural thermal gradient to drive a power plant. Typically around 3,000 mega watts of electrical power can be produced per 100 square miles of ocean surface.
Conventional ocean thermal energy conversion designs use a fluid, such as ammonia, (Closed cycle) or sea water (Open cycle) to rotate a turbine to generate electricity. The disadvantage of conventional designs is that a low pressure vapor turbine requires a much higher ocean temperature gradient to operate. Low pressure vapor turbines are inherently big, expensive and inefficient compared to high pressure hydraulic turbines of similar output. The system also requires a large floating platform to support the heat exchangers, pumps and turbine and the platform should also be designed to withstand severe storms and hurricanes.
As such it would be useful to have a thermal gradient hydroelectric power system and method.
SUMMARY
An object of the present disclosure is to provide an economical, reliable and environmentally friendly thermal gradient energy conversion system for generating electricity and providing the electricity to existing electrical power grids or other independent power consumers.
Specifically, the disclosure describes a power generation system, comprising a submersible evaporator, a vapor line, a condenser above the submersible evaporator, a liquid line, and a turbine system. The submersible evaporator can have a warm water inlet connectable to a natural warm water source, the warm water source having a first temperature; an evaporator shell connected to the warm water inlet; a warm water discharge connected to the evaporator shell; an evaporator working fluid inlet; one or more evaporator coils connected to the working fluid inlet; and an evaporator working fluid discharge connected to the one or more evaporator coils. The vapor line can have a vapor line first end connected to the evaporator working fluid discharge and a vapor line second end. The condenser above the submersible evaporator can comprise a cold water inlet capable of receiving cold water from a natural cold water source; the cold water having a second temperature; a condenser shell connected to the cold water inlet; a cold water discharge connected to the condenser shell; a condenser working fluid inlet connected to the vapor line second end; one or more evaporator coils connected to the working fluid inlet; a condenser working fluid discharge connected to the one or more evaporator coils. The liquid line can have a liquid line first end connected to the condenser working fluid discharge, and a liquid line second end. The turbine system can have a turbine system inlet connected to the liquid line second end; a turbine rotatable by a working fluid, the working fluid having a boiling temperature between the first temperature and the second temperature; and a turbine system outlet that connects to the evaporator working fluid inlet.
Specifically, the method can comprise cycling through a submersed evaporator warm from a natural warm water source, the warm water source having a first temperature. The method also can comprise evaporating a working fluid using the evaporator, and routing the working fluid from the evaporator through a vapor line to a condenser above the evaporator. Finally, the method can also comprise cycling through a condenser cold water from a natural cold water source, the cold water source having a second temperature, and condensing the working fluid, the working fluid having a boiling point between the first temperature and the second temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a schematic flow diagram of a thermal gradient hydroelectric power system.
FIG. 2 illustrates a general arrangement drawing, illustrating a submerged thermal gradient hydroelectric power system.
DETAILED DESCRIPTION
Described herein is a title system and method. The following description is presented to enable any person skilled in the art to make and use the invention as claimed and is provided in the context of the particular examples discussed below, variations of which will be readily apparent to those skilled in the art. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation (as in any development project), design decisions must be made to achieve the designers' specific goals (e.g., compliance with system- and business-related constraints), and that these goals will vary from one implementation to another. It will also be appreciated that such development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the field of the appropriate art having the benefit of this disclosure. Accordingly, the claims appended hereto are not intended to be limited by the disclosed embodiments, but are to be accorded their widest scope consistent with the principles and features disclosed herein.
FIG. 1 illustrates a schematic flow diagram of a thermal gradient hydroelectric power system. One working, suitable fluid for the disclosed system and method is 1,1,1,2,3,3,3-Heptafluoropropane CF3-CHF-CF3 (R-227ea), as it has a good liquid to vapor density ratio and low latent heats of evaporation and condensation, thus giving the fluid a high energy conversion efficiency and available liquid head for the hydraulic turbine at low temperature gradients. Other refrigerant type of fluids can be used, but many give lower energy conversion efficiencies and liquid heads requiring a greater thermal gradient.
The working fluid can be in communication with one or more condenser tubes 8 , a liquid line 12 , a turbine 15 , a generator 17 , one or more vaporizer tubes 24 , and a vapor line 27 . In a no flow or static condition, the liquid level in pipe 12 and vaporizer tubes 24 can be equal.
A suction pipe 1 can feed relatively cold deep water to a pump 6 . In one embodiment, and inline de-aerator 2 and a cyclone 3 can remove debris, small marine organisms and dissolved gasses from the water. The gasses can be extracted by vacuum pump 5 and discharged. The debris and marine organisms removed by cyclone 3 can be returned as waste back to the body of water through a cyclone dip leg 4 . The cold water from pump 6 can be delivered to the shell of condensing heat exchanger 7 and can be in external fluid communication with condenser tubes 8 providing the required quantity of water needed to condense vapor 13 inside condenser tubes 8 . The flow of the cold water can be, in one embodiment, regulated by a control valve 9 . Spent water can be exhausted through condenser outlet 14 back to the body of water at a temperature a few degrees higher than the condenser water inlet temperature. For example, saturated Heptafluoropropane (R-227ea) vapor at 2.67 Bar absolute and 8.3 degrees Celsius will condense when cold ocean water of between 2 and 3 degrees Celsius is pumped from approximately 1000 m below the surface and passed through a condensing heat exchanger. Within these conditions, 9.77 kg of water is required to pass through the heat exchanger to condense 1 kg of R-227ea vapor. Such example is exemplary and not limiting.
The difference in height between liquid level 10 in condenser tubes 8 and liquid level 23 in vaporizer tubes 24 depends on the physical properties of the working fluid, and the available thermal gradient. The optimum height (pressure head) of the liquid can be maintained by regulating the flow of liquid to a turbine or other engine by means of a second control valve 21 . For example, the optimum height for R-227ea with a 20 degrees Celsius thermal gradient is 430 meters. The height can decrease with a decrease in the thermal gradient. The height and flow of the fluid affects the turbine power output.
The condensed liquid 11 from condenser tubes 8 enters the high pressure side of turbine 15 through pipe 12 and is exhausted at a lower pressure into vaporizer tubes 24 . The transfer of energy of the flowing liquid causes turbine 15 to rotate providing the power to drive a generator 17 . The generator power output is regulated by the liquid flow control valve 21 . For example, kg/sec, can produce 1000 kw at a combined turbine and generator efficiency of 93%
A suction pipe 18 can feed warm surface water to pump 20 . Supply line 40 can deliver warm water from pump 20 to a shell side 25 of a vaporizing heat exchanger 16 and can be in external fluid communication with vaporizer tubes 24 providing the required quantity of water to boil the liquid 22 inside vaporizer tubes 24 . The flow of the warm water can be regulated by control valve 19 . The spent water is exhausted through vaporizer outlet 26 back to the body of water at a temperature a few degrees lower than the vaporizer water inlet temperature.
Vapor 27 , generated in vaporizer tubes 24 , can rise in vapor line 28 and can be delivered to condenser tubes 8 . As vapor 27 rises in vapor line 28 , the pressure and temperature of the vapor can decrease to slightly higher than that of condenser tubes 8 within which vapor 27 is again condensed, as previously described, thus completing a closed loop cycle of the working fluid. For example, liquid R-227ea at 3.6 Bar absolute and 17.6 deg. Centigrade will boil when warm ocean surface water of between 22 and 23 deg. Centigrade is pumped from the ocean surface and passed through a boiler and vaporizing heat exchanger. Within these conditions, 9.6 kg of water can boil and vaporize up to 1 kg of (R-227ea) liquid. As the vapor rises in the 430 meter high vapor line, the pressure drops to 2.67 Bar absolute and the temperature to 9.0 deg. Centigrade at the condensing heat exchanger inlet. The cold ocean water of between 2 and 3 deg. Centigrade passing through the condenser can once again condense the vapor. Such example is exemplary, and is not intended to be limiting.
The use of sodium hypochlorite at acceptable concentrations is effective in controlling bio-fouling on the surface of condenser tubes 8 and vaporizer tubes 24 . Salt water or seawater can be drawn through line 29 by pump 30 and delivered to an electro chlorinator 32 . The chlorine gas generated in the electro chlorinator 32 is delivered to the intake of pump 6 through line 33 and pump 20 through line 34 . The spent brine is discharged as waste from the electro chlorinator 32 through line 31 .
In one embodiment, as pumps 6 and 20 draw power from generator 17 , flow regulation of cold water from pump 6 and warm water from pump 20 is critical in achieving optimum heat exchanger performance. High flow rates may not improve heat exchanger efficiencies for a given temperature, thereby consuming unnecessary surplus power produced by the generator 17 .
FIG. 2 illustrates one exemplary arrangement of an equipment, pumps, piping and anchoring system. Cold water suction line 1 , de-aerator 2 , cyclone 3 and pump 6 are formed integrally with condensing heat exchange 7 and can be designed to be neutrally buoyant. In one embodiment, this can be accomplished using low density insulation. Liquid line 11 , turbine 15 and vaporizer 16 can be formed integrally with condensing heat exchanger 7 and also can be designed to be neutrally buoyant by means of low density insulation or other methods known in the art. Vapor line 28 is formed integrally with condensing heat exchanger 7 and vaporizing heat exchanger 16 and is designed to be near neutrally buoyant by means of high density concrete. Warm water suction 18 , pump 20 and warm water line 40 can also be formed integrally with vaporizing heat exchanger 16 and can be designed to be near neutrally buoyant by means of low density insulation. The low density insulation and high density concrete also serve as corrosion protection to the external wetted parts of the equipment and piping. Small equipment, pumps, instrumentation and switchgear are housed in compartment 39 . The power cable from the generator is fed up through vapor line 28 and is connected to the electrical bus bar in compartment 39 . The supply cable for pumps 6 and pump 20 is fed from the electrical bus bar. Surplus electrical power from the bus bar is transmitted via a subsea cable 41 to existing onshore electrical power grids or other independent power consumers.
The entire thermal gradient hydroelectric power system can be submerged and can be anchored by one or more cables 36 . In one embodiment, cables can connect one or more between condenser 7 and anchor block 35 . A floating warning buoy 37 can be attached to compartment 39 .
Various changes in the details of the illustrated operational methods are possible without departing from the scope of the following claims. Some embodiments may combine the activities described herein as being separate steps. Similarly, one or more of the described steps may be omitted, depending upon the specific operational environment the method is being implemented in. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.”
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A thermal gradient hydroelectric power system and method is disclosed herein. Specifically, the method can comprise cycling through a submersed evaporator warm from a natural warm water source, said warm water source having a first temperature. The method also can comprise evaporating a working fluid using said evaporator, and routing the working fluid from the evaporator through a vapor line to a condenser above said evaporator. Finally, the method can also comprise cycling through a condenser cold water from a natural cold water source, the cold water source having a second temperature, and condensing the working fluid, the working fluid having a boiling point between said first temperature and said second temperature.
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FIELD OF THE INVENTION
[0001] This invention relates generally to fluid dispensing containers, and more specifically to advanced spray bottles designed to facilitate access to the entire content of the bottle.
DESCRIPTION OF THE PRIOR ART
[0002] Spray bottles of various sizes can be found in households, industry, the government, and the military. They allow for the dissemination of fluids through spray action for a variety of uses, including cleaning, polishing, and chemical application. Spray bottles on the market, however, suffer from substantial shortcomings. For example, when the level of liquid in a spray bottle is low, the tube that transfers the liquid up to the sprayer mechanism is often not in contact with a sufficient amount of liquid to ensure reliable spray action. Also, tilting the container so as to orient the spray nozzle head at a desired target often reorients the liquid in the container so that the liquid is not positioned to ensure reliable spray action. As such, a significant amount of the liquid in a spray bottle can become inaccessible to a user unless the spray bottle is disassembled. Moreover, additional items such as wipes and auxiliary chemicals are not readily at hand. What is needed is a spray bottle that overcomes these and other shortcomings.
SUMMARY OF THE INVENTION
[0003] The present invention provides an advanced spray bottle in the form of an exemplary spray bottle assembly 10 . Referring to FIGS. 1 and 2 , spray bottle assembly 10 comprises a container 20 having a first side 23 and a second side 22 opposite the first side. The container 20 includes a top collar 24 and a sidewall 21 , the sidewall 21 having an inner surface 21 a and an outer surface 21 b . Container 20 also includes a raised floor 28 with a syncline shape at 28 a , and a level bottom edge 27 located below the raised floor 28 . A first chamber 53 is formed between top collar 24 and raised floor 28 , encompassed by the inner surface 21 a of sidewall 21 . A second chamber 26 , situated below the first chamber 53 , is formed between raised floor 28 and bottom edge 27 , and is also encompassed by the inner surface 21 a of sidewall 21 . The syncline shape at 28 a of the raised floor 28 forms a sluice channel 29 from the first side 23 of the container 20 to the second side 22 of the container 20 .
[0004] The spray bottle assembly 10 may further include a sprayer assembly 40 with a main spray head 41 , a sprayer nozzle 44 with a spray port 45 , a spray trigger 43 , and a spray head internal tube 46 . Spray head internal tube 46 attaches to main spray head 41 . In spray bottle assembly 10 , sprayer assembly 40 attaches to container 20 .
[0005] Raised floor 28 of container 20 has a downward slope from the first side 23 of container 20 to the second side 22 of container 20 . Because of the downward slope, sluice channel 29 is at a higher elevation at the first side 23 of container 20 than at the second side 22 of container 20 , facilitating fluid accumulation. An indent 50 may also be situated at the second side 22 of container 20 to further aid in fluid accumulation as container 20 is tilted.
[0006] A swivel adaptor 47 attaches to spray head internal tube 46 , and an uptake tube 30 attaches to swivel adaptor 47 . The first side 23 of container 20 is curved inward toward the second side 22 such that the uptake tube 30 is pushed toward the second side 22 . Uptake tube 30 includes a bottom aperture 34 located at a lowest point 33 of sluice channel 29 . The bottom aperture 34 of uptake tube 30 is angled in proportion to the syncline shape at 28 a of the raised bottom 28 to enhance access to accumulated fluid.
[0007] The above spray bottle assembly 10 facilitates the most complete emptying of the liquid in container 20 even as container 20 is tilted and rotated by a user. Because of the downward slope of raised bottom 28 , and because of the syncline shape at 28 a , container 20 accumulates even very small quantities of fluid at lowest point 33 of sluice channel 29 . The curved uptake tube 30 and the curved first side 23 of container 20 help position the bottom aperture 34 of uptake tube 30 at the lowest point 33 of sluice channel 29 to permit access to all the accumulated fluid. The angled shape of bottom aperture 34 ensures that uptake tube 30 can access the fluid at the very bottom of sluice channel 29 . Indent 50 forms a secondary cavity 54 for holding fluid at the lowest point 33 of sluice channel 29 even as the user tilts and rotates container 20 . Indent 50 may also serve as a storage adaptor that permits spray bottle assembly 10 , for example, to be hung from a hook or a rung of a ladder. Moreover, second chamber 26 below first chamber 53 holds additional solids, particulate matter, liquids, and applicators for use with the content of the first chamber 53 .
[0008] The objects and advantages of the invention will appear more fully from the following detailed description of the preferred embodiment of the invention made in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Features, aspects, and advantages of exemplary versions of the present invention may be demonstrated by the following non-limiting figures, in which:
[0010] FIG. 1 is a perspective rear-angled view of one exemplary spray bottle assembly of the present invention;
[0011] FIG. 2 a is a back plan view of the spray bottle assembly of FIG. 1 ;
[0012] FIG. 2 b is a side plan view of the spray bottle assembly of FIG. 1 ;
[0013] FIG. 2 c is a front plan view of the spray bottle assembly of FIG. 1 ;
[0014] FIG. 3 illustrates a rear plan view of the spray bottle assembly of FIG. 2 a showing three cut-away views illustrating alternative internal sluice configurations:
[0015] FIG. 3 a is a cut-away of a first embodiment of the bottom section of the spray bottle assembly of FIG. 2 a , taken at line 71 of FIG. 3 , and shows a “V” shaped sluice channel;
[0016] FIG. 3 b is a cut-away of a second embodiment of the bottom section of the spray bottle assembly of FIG. 2 a , taken at line 71 of FIG. 3 , and shows a “curve” shaped sluice channel;
[0017] FIG. 3 c is a cut-away of a third embodiment of the bottom section of the spray bottle assembly of FIG. 2 a , taken at line 71 of FIG. 3 , and shows a “rectangular” shaped sluice channel;
[0018] FIGS. 4 a and 4 b illustrate perspective views of the spray bottle assembly of FIG. 2 a with first alternate cut-away views: FIG. 4 c , taken at line 73 of FIG. 4 a , and FIG. 4 d , taken at line 74 of FIG. 4 b , respectively.
[0019] FIGS. 5 a and 5 b illustrate perspective views of alternative embodiments of the spray bottle assembly of FIG. 2 a with second alternate cut-away views: FIG. 5 c , taken at line 76 of FIG. 5 a , and FIG. 5 d , taken at line 77 of FIG. 5 b , respectively:
[0020] FIGS. 6 a and 6 b illustrate alternate perspective views of the spray bottle assembly of FIG. 2 a with an attached base add-on, and with alternate cut-away views: FIG. 6 c , taken at line 92 of FIG. 6 a , and FIG. 6 d , taken at line 93 of FIG. 6 b , respectively:
[0021] FIGS. 7 a and 7 b illustrates alternate perspective views of the spray bottle assembly of FIG. 2 a with an attached base add-on and with alternate cut-away views: FIG. 7 c , taken at line 100 of FIG. 7 a , FIG. 7 d , taken at line 101 of FIG. 7 b , and FIG. 7 e , taken at line 102 of FIG. 7 b , respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0022] An exemplary spray bottle assembly 10 is shown in FIG. 1 . Spray bottle assembly 10 includes a container 20 attached to a sprayer assembly 40 via a screw-on cap 42 , where screw-on cap 42 attaches to container 20 via cap-container interface threads 48 . Sprayer assembly 40 includes a main spray head 41 , spray trigger 43 , and sprayer nozzle 44 . Screw-on cap 42 houses spray head internal uptake tube 46 , which attaches to swivel adaptor 47 .
[0023] Spray bottle assembly 10 includes an uptake tube 30 attached to sprayer assembly 40 through swivel adaptor 47 . The bottom of swivel adaptor 47 attaches to a top connector section 31 of uptake tube 30 . Uptake tube 30 is inserted into container 20 substantially perpendicular to the base of screw-on cap 42 , where it seats against a top collar 24 of container 20 . Uptake tube 30 has a curvature 35 and a bottom aperture 34 . The curvature 35 of uptake tube 30 provides a contact point 32 with container 20 . Swivel adaptor 47 permits main spray head 41 to rotate without changing the position of uptake tube 30 within container 20 .
[0024] Container 20 of spray bottle assembly 10 includes a raised floor 28 and a bottom edge 27 below raised floor 28 . The bottom edge 27 is level so that container 20 may rest on a platform (not pictured) without tipping over. Bottom edge 27 has a rim 61 that can accept a bottom cap 60 (not shown in this view). Raised floor 28 connects to the container 20 at floor edge 25 . A first chamber 53 is situated between top collar 24 and raised floor 28 , and a second chamber 26 is located between raised floor 28 and bottom edge 27 . A sidewall 21 includes an inner surface 21 a facing the first chamber 53 and the second chamber 26 , and an outer surface 21 b facing the outside of spray bottle assembly 10 . Sidewall 21 holds the contents of first chamber 53 and second chamber 26 within container 20 .
[0025] Referring to FIG. 2 , container 20 includes a first side 23 , a second side 22 opposite the first side 23 , and a syncline shape at 28 a for raised floor 28 . As can be seen in FIG. 1 , the first side 23 of container 20 is curved inward toward second side 22 . The syncline shape at 28 a forms a sluice channel 29 in raised floor 28 for accumulating the fluid in container 20 . Raised floor 28 also has a downward slope from first side 23 to second side 22 . This provides a lowest point 33 of sluice channel 29 , where even small amounts of fluid can accumulate. The curved first side 23 presses against uptake tube 30 at contact point 32 such that bottom aperture 34 remains at lowest point 33 . The bottom aperture 34 of uptake tube 30 is additionally angled so that it better mates with the syncline shape at 28 a of sluice channel 29 . Such positioning of the angled bottom aperture 34 at lowest point 33 permits spray bottle assembly 10 to act on extremely low levels of fluid in container 20 .
[0026] The second side 22 of container 20 may include an indent 50 with a top slope 51 and a bottom slope 52 . Indent 50 provides a secondary cavity 54 for holding fluid when container 20 is being tilted by a user. The size of secondary cavity 54 can be increased or decreased by enlarging or shrinking indent 50 , respectively. Indent 50 is positioned at the second side 22 so that the fluid that accumulates at lowest point 33 of sluice channel 29 can be captured within secondary cavity 54 despite the orientation of container 20 . Bottom aperture 34 of uptake tube 30 , when located at the lowest point 33 of sluice channel 29 , is below bottom slope 52 of indent 50 . Secondary cavity 54 , provided by indent 50 , acts as a supplementary area of containment such that fluid in container 20 can be captured and made available for passage through uptake tube 30 via bottom aperture 34 .
[0027] Referring to FIG. 2 a , a rear view of the spray bottle assembly 10 of FIG. 1 shows the syncline shape at 28 a of raised floor 28 . Sluice channel 29 is shown vertically, representing the downward slope from the first side 23 (visible in FIG. 2 a ) of container 20 to the second side 22 (hidden in FIG. 2 a , visible in FIG. 2 c ). As such, sluice channel 29 begins at a higher elevation at the first side 23 of container 20 and terminates at lowest point 33 . Because of the downward slope, the fluid in container 20 is gravitationally drawn along sluice channel 29 to lowest point 33 .
[0028] FIG. 2 b shows the sluice channel 29 of downward sloping raised floor 28 . Also shown in FIG. 2 b is a middle indent section 55 of indent 50 . In FIG. 2 c , sprayer nozzle 44 is shown including a spray port 45 , out of which the fluid in container 20 sprays. FIG. 2 c also shows a front-view outline of indent 50 .
[0029] A rear-view of spray bottle assembly 10 is shown in FIG. 3 . FIGS. 3A , 3 B and 3 C of bottom portion 70 of container 20 are depicted and show three variations of the sluice channel configuration. Depicted in FIG. 3A is a cross section of raised bottom 28 attached to sidewall 21 at floor edge 25 . Sluice channel 29 is shown with the syncline shape at 28 a forming a “V” shape. Depicted in FIG. 3B is a cross section of raised bottom 28 attached to sidewall 21 at floor edge 25 . Sluice channel 101 is shown with the syncline shape at 28 a forming a curved shape. Depicted in FIG. 3C is a cross section of raised bottom 28 attached to sidewall 21 at floor edge 25 . Sluice channel 102 is shown with the syncline shape at 28 a forming a rectangular shape. In effect, the syncline shape at 28 a of raised floor 28 provides a downward “dip,” away from top collar 24 toward bottom edge 27 , for accumulating small amounts of fluid. It is also noted that floor edge 26 is at a higher elevation than the bottom of the dip of sluice channel 29 , so that fluid in first chamber 53 is gravitationally drawn to the bottom of sluice channel 29 .
[0030] FIGS. 4 a and 4 b depict cut-away views FIG. 4 c and FIG. 4 d , respectively, of the bottom portion FIG. 4 a and FIG. 4 b , showing two alternative exemplary versions of spray bottle assembly 10 .
[0031] Cut-away view FIG. 4 c depicts a rear view of an exemplary bottom portion 72 of container 20 . First chamber 53 is shown with the syncline shape at 28 a of raised bottom 28 attached to sidewall 21 at floor edge 25 . In this version, a solid, liquid, or particulate 64 is shown in the second chamber 26 between the syncline shape at 28 a of the raised bottom 28 and the bottom edge 27 of container 20 . Rim 61 of bottom cap 60 spans the circumference of bottom edge 27 , and bottom cap 60 acts as a retention device for solid, liquid, or particulate 64 . Solid, liquid, or particulate 64 may be dispensable by the removal of bottom cap 60 .
[0032] Cut-away view FIG. 4 d depicts a rear view of another exemplary bottom portion 72 of container 20 . In this version, second chamber 26 is shown empty of any solid, liquid, or particulate 64 . Bottom cap 60 is shown separated from second chamber 26 and bottom edge 27 of container 20 .
[0033] FIG. 5 a and FIG. 5 b depict views cut-away views FIG. 5 c and FIG. 5 d , respectively, of bottom portion 75 , showing two additional exemplary versions of spray bottle assembly 10 .
[0034] Cut-away view FIG. 5 c shows the bottom portion 75 of container 20 with a cross section of raised bottom 28 attached to sidewall 21 at floor edge 25 . In this version, second chamber 26 includes a compressed applicator 62 . Bottom cap 60 acts as a retention device for compressed applicator 62 .
[0035] Cut-away view FIG. 5 d depicts a rear view of another version of bottom portion 75 . In this version, second chamber 26 is shown empty. An uncompressed applicator 63 attached to bottom cap 60 is shown free of its confinement within the second chamber 26 . The removal of the applicator 63 attached to bottom cap 60 allows the applicator 63 to expand from it stored size of FIG. 5 c to its expanded size of FIG. 5 d . Applicator 63 may be usable with the content of first chamber 53 or with the solid, liquid, or particulate 64 stored in second chamber 26 .
[0036] FIGS. 6 a and 6 b depict cut-away views 92 and 93 depicting two further exemplary versions of spray bottle assembly 10 .
[0037] Cut away view FIG. 6 c shows a base add-on 90 (shown as cut-away view FIG. 6 d in FIG. 6 b ) attached to the bottom edge 27 of container 20 . In FIG. 6 c , bottom edge 27 of container 20 is inserted into, and is parallel with, base add-on 90 . Base add-on 90 in FIGS. 6 a and 6 b has an interior space 81 and an exterior wall 82 , and exterior wall 82 includes a hollow wall interior 83 . Bottom edge 27 of container 20 butts against, and has its movement stopped by, an interior boss 84 . Placement of bottom edge 27 into interior space 81 creates a uniform seal between bottom edge 27 and base add-on 90 , such that base add-on 90 acts as a new bottom surface for container 20 . This bottom surface includes a base pad 89 having a bottom side 88 . Base pad 89 enlarges the overall footprint of container 20 , as a top side 87 of base pad 89 projects outward parallel with the bottom side 88 . Such outward projection results in a broad base, serving to stabilize container 20 when placed on uneven or tilted surfaces. The bottom side 88 of base pad 89 can also have a traction-enhancing non-slip surface (not shown) so that container 20 can be placed on a wet or moving surface without slipping.
[0038] This arrangement also provides a large cavity, comprising interior space 81 and second chamber 26 , between raised bottom 28 and an interior bottom 85 of base add-on 90 . Here, base add-on 90 , which includes top edge 86 , forms a sealed container that is capable of holding a solid, liquid, or particulate 64 within its confines.
[0039] FIG. 7 a and FIG. 7 b show a base add-on 110 shown as a cut-away view in FIG. 7 c and FIG. 7 e . FIG. 7 d shows a cut-away view depicting the bottom portion 101 of container 20 of a variant version of spray bottle assembly 10 .
[0040] Cut-away view FIG. 7 c depicts the union of the two parts of a dual chamber access system of a variant version of spray bottle assembly 10 .
[0041] Cut-away view FIG. 7 d and FIG. 7 e depict the two separate parts of a dual chamber access system of a variant version of spray bottle assembly 10 .
[0042] Cut away FIG. 7 c shows a base add-on 110 (shown individually as FIG. 7 e and attached to the container 20 in cut-away view FIG. 7 c ) attached to the bottom edge 27 of container 20 . In FIG. 7 a , bottom edge 27 of container 20 is inserted into, and is parallel with, base add-on 110 . Base add-on 110 in FIGS. 7 c and 7 e has an interior space 181 and an exterior wall 182 , and exterior wall 182 includes a hollow wall interior 183 . Bottom edge 27 of container 20 butts against, and has its movement stopped by, an interior boss 184 . Placement of bottom edge 27 into interior space 181 creates a uniform seal between bottom edge 27 and base add-on 110 , such that base add-on 110 acts as a new bottom surface for container 20 . This bottom surface includes a base pad 189 having a bottom side 188 . Base pad 189 enlarges the overall footprint of container 20 , as a top side 187 of base pad 189 projects outward parallel with the bottom side 188 . Such outward projection results in a broad base, serving to stabilize container 20 when placed on uneven or tilted surfaces. The bottom side 188 of base pad 189 can also have a traction-enhancing non-slip surface (not shown) so that container 20 can be placed on a wet or moving surface without slipping.
[0043] In this variant of spray bottle assembly 10 , as shown in cut-away view FIG. 7 e , the base add-on 110 has a central vertical post 103 protruding from the interior bottom 185 of base add-on 110 . When the base add-on 110 is placed on the bottom of container 20 as shown in FIG. 7 a and cut-away view FIG. 7 c the tip 104 of the central vertical post 103 protrudes from the interior bottom 185 of base add-on 110 to a length which impacts a flap seal 105 which covers opening 107 and central vertical post 103 passes through opening 107 in the interior raised bottom 108 of the container 20 . When central vertical post 103 passes through opening 107 it forces the flap seal 105 in the interior raised bottom 108 of the container 20 to open via its hinge 106 . The flap seal 105 is normally sealed via its hinge 106 to the interior raised bottom 108 of the container 20 as shown in cut-away view FIG. 7 d of FIG. 7 b . The flap seal 105 is attached to the upper surface of raised bottom 108 of the first chamber 53 in a manner which covers and seals the opening 107 and the weight of the solid, liquid, or particulate 64 contents of first chamber 53 holds flap seal 105 in communication with the raised bottom 108 and seals opening 107 . When flap seal 105 is held open by central vertical post 103 , as shown in FIG. 7 c , the opening 107 can communicate solid, liquid, or particulate 64 contents from first chamber 53 to the second chamber 181 which is created by the joining of base add-on 110 to container 20 . The base add-on 110 may be removed from the bottom of container 20 , as shown in FIG. 7 b , to refill its contents. When the base add-on 110 is removed from the bottom of container 20 , as shown in FIG. 7 b the central vertical post 103 is withdrawn from the opening 107 and flap seal 105 via its hinge 106 reseals opening 107 , as shown in FIG. 7 d , and prevents egress of any further solid, liquid, or particulate 64 content from first chamber 53 .
[0044] It is understood that the invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims.
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An advanced spray bottle facilitates complete emptying of liquid in its container even as the container is rotated and tilted. The container has a primary chamber with a raised floor that has a syncline shape and that forms a sluice channel. The raised floor slopes downward across the container to route fluids to a lowest point of the sluice channel. An indent in the container provides a cavity for further capture and concentration of liquids. The container is shaped to guide a bottom aperture of the uptake tube to the lowest point of the sluice channel. The bottom aperture of the uptake tube is angled so as to better fit within the lowest point of the sluice channel. A secondary chamber at the base of the container, with an egress to the primary chamber holds additional solids and liquids. Alternate add-on bases for the container provide additional functionality.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to Korean Patent Application Number 10-2010-0029200 filed Mar. 31, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the structure of an automatic transmission equipped with a vehicle, and more particularly to a valve body cover of an automatic transmission.
[0004] 2. Description of Related Art
[0005] The valve body of automatic transmission is a device that can control the operation of the automatic transmission, using hydraulic pressure, which is disposed in a transmission case of the automatic transmission and of which the outer side is covered and protected by a valve body cover mounted on the transmission case.
[0006] The valve body cover is provided with an oil level plug to check whether an appropriated amount of oil exists in the transmission case.
[0007] In the related art, a nut is welded where the oil level plug is mounted in valve body covers made of metal and a nut is inserted in valve body covers made of plastic, in order to mount the oil level plug, which is a bolt type, in the nut with predetermined torque.
[0008] Theses structure, however, had a problem that the nut is likely to separate from the valve body cover after a long time and additional works are required due to inserting or welding the nut in manufacturing the valve body cover, such that the manufacturing cost increases and the weight is increased by the metal nut.
[0009] The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY OF THE INVENTION
[0010] Various aspects of the present invention are directed to provide a valve body cover of an automatic transmission that makes it possible to reduce the manufacturing works, the manufacturing cost, and the weight, and improve durability, by mounting an oil level plug without additionally inserting or welding a nut.
[0011] In an aspect of the present invention, the valve body cover of an automatic transmission may include a cover plate having a hole; an oil level plug having a cap detachably mounted onto the cover plate from the outside of the cover plate and an insertion extended from the cap and selectively inserted into the hole of the cover plate; and rotational pressing members formed in the insertion of the oil level plug and the cover plate respectively to press the cap against the cover plate while the insertion of the oil level plug inserted in the hole may be rotated relatively with respect to the cover plate.
[0012] The valve body cover of the automatic transmission may further include a sealing member which may be disposed between the cap and the cover plate and compressed by the cap for sealing a gap formed between the cap and the cover plate while the cap may be rotatably coupled to the cover plate, wherein the sealing member may be formed in a ring to be fitted around the insertion, wherein the cover plate includes a receiving groove formed along the hole of the cover place to retain the sealing member therein, and wherein a locking protrusion may be formed on an inner circumference of the receiving groove to couple the sealing member in the receiving groove.
[0013] The rotational pressing members may include a locking protrusion disposed with a predetermined distance from the cap in a longitudinal direction of the insertion and protruding from the insertion radially from the longitudinal direction of the insertion; a receiving hole formed in the cover plate and extending from the hole of the cover plate outwards so as to allow the locking protrusion of the insertion to pass through the receiving hole at a predetermined position of the cover plate; and a spiral protrusion spirally protruding from the cover plate toward the inside of the cover plate such that the locking protrusion passing through the receiving hole moves toward the inside of the cover plate in the longitudinal direction of the insertion while the locking protrusion of the insertion rotates along the spiral protrusion.
[0014] The spiral protrusion may spirally protrude from the cover plate toward the inside of the cover plate with a predetermined slope with respect to the cover plate along a circumferential direction of the hole.
[0015] The valve body cover of the automatic transmission may include a rotation range restricting member that may be disposed between the oil level plug and the cover plate to restrict a rotation of the oil level plug rotating with respect to the cover plate within a predetermined range such that the locking protrusion of the insertion spirally move along the spiral protrusion with the predetermined slope and may be mounted to the spiral protrusion, wherein the rotation range restricting member has a restricting leg protruding from the cap with a predetermined length; and an arc locking slot formed on the cover plate such that the restricting leg may be inserted and locked therein to mount the locking protrusion onto the spiral protrusion, wherein the rotation range restricting member further includes an arc guide slot which may be integrally formed to one end portion of the arc locking slot, wherein a ridge portion may be formed between the arc guide slot and the arc locking slot to make a thickness of the arc guide slot smaller than the thickness of the arc locking slot, and wherein the restricting leg may be elastically biased against the ridge portion of the arc guide slot such that the restricting leg sliding along the arc guide slot may be locked into the arc locking slot when the restricting leg passes over the ridge portion into the arc locking slot.
[0016] The cap may be formed in a circular plate and the restricting leg protrudes downwards from an outer circumference of the cap toward the cover plate with the predetermined length.
[0017] A tool groove may be formed approximately at the center of the cap to insert a tool thereto and apply a rotational force to rotate the oil level plug with respect to the cover plate.
[0018] The present invention has a structure that makes it possible to combine or separate an oil level plug with or from cover plate itself of a valve body cover, without additionally inserting or welding a specific nut. Therefore, it is possible to reduce manufacturing works and manufacturing cost of a valve body cover of an automatic transmission and also reduce the weight and improve durability with stable sealing, by changing the structure of the oil level plug.
[0019] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a showing a valve body cover of an automatic transmission according to the present invention.
[0021] FIG. 2 is a view showing in detail the main parts that are exploded of FIG. 1 .
[0022] FIG. 3 is a view showing the oil level plug of FIG. 2 .
[0023] FIG. 4 is a view comparing the inner side and the outside around a hole of a cover plate.
[0024] FIG. 5 is a cross-sectional view illustrating the operation the oil level plug mounted on the cover plate.
[0025] FIG. 6 is a view illustrating the process of mounting the oil level plug to the cover plate.
[0026] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0027] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0029] Referring to FIGS. 1 to 4 , a valve body cover of an automatic transmission according to an exemplary embodiment of the present invention includes a cover plate 3 having a hole 1 and mounted to a transmission case to cover a valve body, an oil level plug 9 having a cap 5 mounted to be positioned outside cover plate 3 and an insertion 7 that is inserted into hole 1 from cap 5 , a rotational pressing member formed in oil level plug 9 and cover plate 3 to gradually move cap 5 to cover plate 3 when oil level plug 9 is rotated relatively to cover plate 3 , with insertion 7 in hole 1 , and a sealing member 11 compressed between cap 5 and cover plate 3 for sealing, when cap 5 is moved to cover plate 3 .
[0030] That is, the portion implemented by a nut in the related art is integrally formed with cover plate 3 and oil level plug 9 that was a bolt type in the related art is modified, such that oil level plug 9 is assembled and disassembled only by one rotation at the most with respect to cover plate 3 .
[0031] It is preferable that cover plate 3 is made of plastic to achieve the complicate shape around hole 1 at one time by injection molding and oil level plug 9 assembled with it may be made of similar plastic.
[0032] In the present embodiment, the rotational pressing member includes locking protrusions 13 protruding radially from insertion 7 , receiving holes 15 extending from hole 1 of cover plate 3 to allow locking protrusions 13 to pass through the receiving holes 15 at predetermined positions, spiral protrusions 17 spirally protruding toward the inside of cover plate 3 such that locking protrusions 13 passing through receiving holes 15 can move toward the inside of cover plate 3 while rotating with cover plate 3 .
[0033] Therefore, when insertion 7 is inserted in hole 1 , with locking protrusion 13 positioned to pass through receiving holes 15 , and the cap 5 is rotated, as shown in FIG. 5 , locking protrusions 13 spirally moves along spiral protrusions 17 and cap 5 moves to cover plate 3 .
[0034] An exemplary embodiment of the present invention may include a receiving groove 20 formed in the cover plate 3 around the hole 1 and receive a sealing member 11 therein. The receiving groove 20 may include at least a locking protrusion 22 on the inner circumference thereof to retain the sealing member 11 firmly.
[0035] In this operation, the sealing member 11 is pressed by the movement of cap 5 between cap 5 and cover plate 3 to seal the space between cap 5 and cover plate 3 , thereby preventing oil inside cover plate 3 from leaking outside.
[0036] In the present embodiment, sealing member 11 is formed in a ring fitted around the insertion 7 , as shown in FIG. 2 to seal the entire circumference of insertion 7 of oil level plug 9 without a gap between insertion 7 and cover plate 3 .
[0037] Sealing member 11 may be made of the same materials of common sealing parts of the related art, such as rubber or urethane.
[0038] In the present embodiment, a rotation range restricting member that restricts the rotation of oil level plug 9 rotating with respect to cover plate 3 within a predetermined range such that locking protrusions 13 spirally move along spiral protrusions 17 is disposed between oil level plug 9 and cover plate 3 .
[0039] The cover plate 3 includes an arc guide slot 23 . The rotation range restricting member has restricting legs 19 protruding from cap 5 to cover plate 3 through the arc guide slot 23 formed to guide the rotational movement of the restricting legs 19 and the arc locking slots 21 formed an end portion of the arc guide slot 23 on cover plate 3 such that restricting legs 19 are inserted and locked therein after a predetermined rotation along the arc guide slot 23 .
[0040] In an exemplary embodiment of the present invention; the arc guide slot 23 includes a ridge portion 27 such that the thickness of the arc guide slot 23 is smaller than the thickness of the arc restricting slot 21 . The restricting leg 19 is elastically biased toward the insertion 7 such that when the restricting legs 19 rotates into the arc locking slots 21 over the ridge portion 27 , the restricting leg 19 is snapped thereto.
[0041] Cap 5 is formed in a circular plate, restricting legs 19 protrude downward from the outer circumference of circular plate-shaped cap 5 to cover plate 3 , and a tool groove 23 is formed at the center of cap 5 to insert a tool and apply rotational force.
[0042] Therefore, referring to FIG. 6 , when insertion 7 is inserted in hole 1 , with locking protrusions 13 aligned with receiving holes 15 , the position shown at the upper portion of FIG. 6 is achieved, and then, as it is rotated by inserting an appropriate tool in tool groove 23 , as shown at the lower portion in FIG. 6 , restricting legs 19 rotate and stop within the allowable range of arc locking slots 21 . Accordingly, sealing member 11 between cap 5 and cover plate 3 is sufficiently pressed by the rotation and desired sealing is sufficiently achieved.
[0043] Meanwhile, tool groove 23 on cap 5 may be modified in a common hex wrench groove or groove that a driver can be inserted in, other than the rectangular groove shown in the figure.
[0044] For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0045] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A valve body cover of an automatic transmission, may include a cover plate having a hole, an oil level plug having a cap detachably mounted onto the cover plate from the outside of the cover plate and an insertion extended from the cap and selectively inserted into the hole of the cover plate, and rotational pressing members formed in the insertion of the oil level plug and the cover plate respectively to press the cap against the cover plate while the insertion of the oil level plug inserted in the hole is rotated relatively with respect to the cover plate.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. application Ser. No. 11/028,355, filed Dec. 30, 2004, entitled SPANNING TREE PROTOCOL WITH BURST AVOIDANCE, the entire contents of which are incorporated by reference herein.
TECHNICAL FIELD
[0002] The invention generally relates to bridge or like device adapted to avoid bursts of bridge protocol data units in a data communications network. In particular, the invention relates to a system and method for limiting the conditions under which bridge protocol data units are transmitted to prevent the propagation of erroneous information regarding the identity of a root bridge.
BACKGROUND
[0003] Illustrated in FIG. 1 is a data communications network 100 including a plurality of bridges 101 - 120 operatively coupled in the form of a ring by network links 130 . The topology of the network 100 is useful to understand the drawbacks attributable to the prior art as well as the advantages of the present invention discussed in more detailed below. Each of the bridges 101 - 120 includes a plurality of network ports enabled with a link management protocol to resolve transmission loops in the network 100 that can give rise to broadcast storms. The link management protocol may be selected, for example, from the group comprising the Spanning Tree Protocol (STP) standardized in International Electrical and Electronics Engineers (IEEE) standard 802.1D 2004, the Rapid Spanning Tree Protocol (RSTP) defined in IEEE standard 802.1w, and IEEE standard 802.1Q 2003 addressing the use of multiple spanning trees in virtual local area network (VLAN) bridges in accordance with the Multiple Spanning Tree Protocol (MSPT) defined in IEEE standard 802.1s, each of which is hereby incorporated by reference herein.
[0004] In accordance with the RSTP, the bridges 101 - 120 are adapted to exchange BPDUs protocol data unit (BPDUs) messages for purposes of determining which of the plurality of bridges is to serve as the root bridge among as well as the role of each port of every bridge. To determine the root bridge and the applicable port roles, the bridges exchange BPDU messages with priority information referred to as message priority vectors (MPVs). A bridge generally transmits BPDUs at a regular interval given by a bridge Hello time timer value, i.e., a Hello time, set forth in the RSTP standard or sends the BPDUs when a change in the spanning tree topology is initiated. A MPV has the following structure: <Root_Id, Root_Path_Cost, Designated_Bridge_ID, Designated_Port_ID, Port ID>, each of the components of the vector being well understood by those skilled in the art. Upon receipt of a BPDU, a bridge port compares the received MPV with its own priority vector referred to as a port priority vector (PPV). If the received MPV is “superior” to the PPV, i.e., numerically lower, the port's state machine computes the role of each port of every bridge, which may confirm the existing spanning tree topology or, if necessary, initiate a spanning tree topology change.
[0005] The Root bridge in the spanned tree is generally the bridge with the lowest bridge ID (BID), i.e., the lowest MAC address, and resides at the head of the spanning tree. Although, every bridge initially considers itself the root bridge, each bridge learns the identity of the bridge with the lowest BID through the exchange of BPDUs. In determining the role of the ports of the plurality of bridges, each of the ports is classified as either a root port, a designated port, a backup port, or an alternate Port. With the exception of the root bridge, every bridge has one root port, namely the port of the bridge that provides the lowest cost path to the Root Bridge. A Designated port is an interface used to send and receive frames on a specific network segment. Although the designated port may be one of a plurality ports accessible to the specific network segment, the Designated port is determined based upon the lowest root cost path. The Alternate and Backup ports provide connectivity if other network components fail. An Alternate port offers an additional path to the Root bridge beyond the path provided by a bridge's own Root port. A Backup port offers an additional path to the leaves of the spanning tree beyond the path provided by the Designated port for the network segment.
[0006] The ports of a bridge may also be characterized by one or more of a plurality of states, namely a Forwarding state, a Discarding state, and a Learning state, each of which is set forth in the 802.1D 2004 standard. In the Learning state, the port temporarily learns the identities of nodes reachable through the port but does not forward frames. In the Forwarding state, which generally follows the learning state, the bridge forwards frames in accordance with a filtering database. In the Discarding state, all traffic is dropped with the exception of control traffic at Layer 2 of the Open Systems Interconnect (OSI) reference model.
[0007] Illustrated in FIG. 2 is a message diagram representing a BPDU traffic burst in the communications network 100 of FIG. 1 as a result of a link failure. The term “traffic burst” as used herein refers to situations in which a bridge enabled with RSTP simultaneously transmits a plurality of BPDUs on one or more of its ports at the same time upon receipt of a BPDU with “superior information” on any port. “Superior Information” as used herein is defined in the 802.1D 2004 standard paragraph 17.6 entitled “Priority vector calculations.” The BPDU traffic burst of FIG. 1 represents a worst case scenario that could occur under the circumstances stated below. As a consequence of a BPDU traffic burst, the convergence of the spanning tree may be delayed.
[0008] For purposes of this example, bridge 111 has the lowest MAC address of the set of bridges 111 - 120 on the left side of the network 100 , the bridges 112 - 119 have consecutively higher MAC addresses starting from bridge 112 , and bridge 119 has the highest MAC address. The MAC addresses of the bridges 102 - 110 on the right side of the network 100 are not relevant to this discussion below. Assuming that the communications links—including link 130 A—are active, the first port 111 A of the bridge 111 may serve as a Root bridge while the second port 111 B may serve as an Alternate port 111 B. In addition, the bridges 101 - 120 are configured with the RSTP default values including a migrate time of 3 seconds, a bridge hello time of 2 seconds, a bridge max age of 20 seconds, a bridge forward delay of 15 seconds and a transmit hold count of 6.
[0009] Bridge 112 includes a designated port 112 A for transmitting frames to the adjacent local area network (LAN) segment while bridge 111 includes an alternate port 111 providing an alternate path from the intermediate LAN segment to the root bridge.
[0010] For purposes of the following example, it is assumed that the bridge 101 is the Root bridge, bridge 102 is designated bridge for purposes of bridges 103 - 111 , and bridge 120 is designated bridge with respect to bridges 112 - 119 . If the communication link 130 A between the bridge 120 and the root bridge 101 fails and the exchange of data terminated 202 , the bridges exchange BPDUs to re-establish the appropriate propagation path in accordance with the RSTP protocol. After the failure of link 130 A and the restructure of the spanning tree, all frames transmitted to the plurality of bridges 102 - 120 will be transmitted through the bridge 102 .
[0011] Upon detection of the link failure, port 120 B of bridge 120 is reclassified from a Root port to a disabled port and all root port information purged. In the absence knowledge of the root bridge 101 or the path thereto, bridge 120 believes it to be the root bridge and sends a BPDU 204 to bridge 119 announcing that bridge 120 is the new root bridge. Upon receipt of the BPDU 204 from bridge 120 , bridge 119 discards its root port information and the bridge port 119 B compares the received MPV with its own PPV vector. When bridge 119 determines that it has better vector, bridge 119 immediately transmits BPDUs 206 from each of its ports announcing that bridge 119 is the new root bridge. Although port 120 A of bridge 120 transitions to a designated port, bridge 118 compares 207 the received MPV from bridge 119 with its own PPV vector. When bridge 118 determines that it has a superior priority vector, bridge 120 immediately transmits BPDUs 208 to its neighbors announcing that bridge 118 is the new root bridge. Port 119 A of bridge 119 transitions to the designated port state and the BPDU 208 forwarded to the bridge 120 .
[0012] The pattern described above is repeated many times over with each bridge from bridge 117 to bridge 111 receiving a BPDU announcing that the transmitting bridge is the root bridge. Each time, the bridge must compare 209 - 215 the received priority vector with the local PPV and immediately respond with a new BPDU identifying itself as the root bridge. At each step, the BPDUs are transmitted to downstream bridges all the way to bridge 120 , thereby giving rise to a significant BPDU traffic burst. The burst only subsides only after the alternate port 111 B of bridge 111 transmits a BPDU 210 identifying bridge 101 as the true root bridge. This BPDU identifying the proper root bridge is propagated to each of the bridges 112 - 120 and each bridge updates its root port information. As one skilled in the art will appreciate, proposal/agreement BPDUs (not shown) may continue to propagate through the network 100 in accordance with the RSTP protocol. As can be seen, the bridge 120 adjacent to the failed link 130 A receives ten BPDUs in the BPDU traffic burst. In general, the minimum burst size experienced by a bridge is equal to the number of bridges between the root bridge 101 and the alternate bridge 111 in the direction of the failure.
[0013] The first version of Spanning Tree in the legacy 802.1D 1998 standard introduced a burst limiter to inhibit BPDU traffic burst like that described above. A port compliant with the RSTP standard keeps track of the number of BPDUs sent with a standard variable referred to as the “txCount,” which is incremented each time a BPDU is transmitted. A BPDU is not transmitted if the txCount reaches a given maximum called txHoldCount. The txCount number is also automatically decremented each second, thereby allowing the BPDU transmissions to resume at a later time. As such, a port is permitted to burst as quickly as possible until the txHoldCount is reached, and then transmit one BPDU maximum per second thereafter as long as txCount remains greater than or equal to txHoldCount.
[0014] Currently, the txHoldCount is permitted to range from one to ten, with a default value set to six. Since the number of BPDU that may be transmitted is correlated to number of nodes in the network, a relatively larger network increases the chances of one or more bridges reaching such a threshold. As a result, the time required for convergence can be delayed between one to several seconds as a function of the frequency with which the burst limiter is triggered. There is therefore a need for a system and method to restrict the number of BPDUs transmitted while enabling the network to converge as quickly as possible without undue delay resulting from the RSTP burst limiter.
SUMMARY
[0015] The invention in the preferred embodiment features a system and method for controlling bridge protocol data unit bursts in a data communications network comprising a plurality of bridges or like devices. The switching device preferably comprises a first port enabled with a link management protocol as well as a burst control state machine. The burst control state machine is adapted to receive a first BPDU from a bridge reachable through the port and, under certain conditions, delay the transmission of a second BPDU advertising that the switching device is the new root bridge when, in fact, it is not. The delay is preferably long enough to enable another bridge, either the root bridge or designated bridge, to transmit the identity of the true root bridge. The delay, e.g., a burst control delay, is preferably equal to or less than a Hello time timer value generally defined to be 2 seconds in the RSTP standard. In the preferred embodiment, the conditions include the following: the first port is a Root port in the Forwarding state; the first port transitions from a Root port to a Designated port in response to the first BPDU. The conditions may further include the following: forwarding information associated with the first port is current, i.e., infoIs=RECEIVED; and a topology change indicator received with the first BPDU is false, i.e., proposing is equal to FALSE.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which:
[0017] FIG. 1 is a data communications network including a plurality of bridge enabled with the spanning tree protocol (STP);
[0018] FIG. 2 is an RSTP message exchange between the bridges of the data communications network, in accordance with the prior art;
[0019] FIG. 3 is a Burst Control (BC) switch adapted to perform link management burst control, in accordance with the preferred embodiment of the present invention;
[0020] FIG. 4 is the Port State Information Machine of a prior art bridge enabled with the RSTP;
[0021] FIG. 5 is the Burst Control State Machine of the BC switch, in accordance with the preferred embodiment of the present invention;
[0022] FIG. 6 is the Update state of the Port State Information Machine of the prior art; and
[0023] FIG. 7 is an UPDATE_BURST_AVOD state implemented in the Burst Control Port State Machine, in accordance with the preferred embodiment of the present invention;
[0024] FIG. 7 is an UPDATE_BURST_AVOID state implemented in the Burst Control Port State Machine, in accordance with the preferred embodiment of the present invention;
[0025] FIG. 8 is a Port Role Selection State Machine implemented in the Burst Control Port State Machine, in accordance with the preferred embodiment of the present invention; and
[0026] FIG. 9 is an RSTP message exchange between the BC bridges of the data communications network of FIG. 1 , in accordance with the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Illustrated in FIG. 3 is a switching device adapted to perform link management burst control in accordance with the preferred embodiment. In the preferred embodiment, the switching device is a bridge 300 although the invention is equally applicable to routers and multilayer switches adapted to provide forwarding and routing operations at Layers 2 and 3 of the Open Systems Interconnection (OSI) reference model. The switch 300 in the preferred embodiment includes a plurality of Layer 2 interfaces represented by MAC entities 302 , a MAC relay entity 306 , and higher layer entities 308 . Each of the MAC entities 302 includes a frame receiver 310 and frame transmitter 312 operably coupled to a local area network (LAN) 304 A- 304 B via an external port 300 A- 300 B, respectively.
[0028] The MAC entity 302 handles all Media Access Method Dependent Functions (MAC protocol and procedures) in accordance with the RSTP standard including the inspection of all frames received on the attached LAN and transmission of frames received from the MAC relay entity 306 and higher layer entities 308 . The MAC relay entity 306 interconnects the plurality of ports 304 A- 304 B and handles the Media Access Method Independent Functions of relaying frames between Bridge Ports including filtering frames and source learning. The MAC relay entity 306 includes a filtering database 314 and a plurality of port state information (PSI) tables 316 . The filtering database 314 retains filtering information including known forwarding address and applicable ports 304 A- 304 B to which received frames may be forwarded. The PSI table 316 associated with a port includes a record of the learning and forwarding states of the port, i.e., whether the port is currently in the disabled, blocking, listening, learning, forwarding state. In the preferred embodiment, the PSI table 316 also maintains a record of burst control information (BCI) 318 including “burstAvoidanceControl” and “burstAvoid” parameters described in more detail below.
[0029] The higher layer entities 308 include logical link control (LLC) entities 320 and a bridge protocol entity 322 . The LLC entities 320 encompasses both the Link Layer capabilities—which include demultiplexing, for example—provided by LLC as specified in International Organization for standards (ISO)/International Electrotechnical Commission (IEC) 8802-2 as well as the Type interpretation of the Length/Type field specified in IEEE Std 802.3. The bridge protocol entity 322 maintains a plurality of RSTP state machines including a Port Information State Machine (PISM) adapted to execute the burst avoidance protocol, and maintains RSTP protocol parameters and configuration timers. The PISM is defined in the RSTP standard and for replying to Configuration BPDUs and responding to Transmit Topology Change Notification (TCN) BPDUs. In the preferred embodiment, the enhanced PISM includes a Burst Control State Machine (BCSM) 324 that modifies the timing of topology changes notifications BPDUs to prevent potentially injurious BPDU traffic bursts.
[0030] In the preferred embodiment, the BCSM 324 is an improvement upon the PISM set forth in the RSTP standard hereby incorporated herein by reference. In particular, the BCSM 324 causes the switching device 300 to test for various conditions upon receipt of a TCN BPDU at a designated port and, if those conditions are met, the device 300 induces a delay in the transmission of configuration BPDUs from the same designated port. The induced delay, referred to as a burstAvoidDelay, prevents the particular switching device from transmitting a configuration BPDU identifying its own superior priority vector from the switching device before a configuration BPDU is received from the root bridge or an alternate port. In this manner, the switching device suppresses the transmission of one or more BPDUs identifying itself as the root before the identity of the true root bridge is advertised by the root bridge or the alternate port. Depending on the topology of the network and the MAC addresses of the bridges in the network, the preferred embodiment may significantly reduce the number of BPDUs transmitted and therefore potentially reduce the time required to determine the proper spanning tree topology.
[0031] Each of the bridge ports of switching module 300 is adapted to invoke the burst avoidance process in response to the receipt of a BPDU under the proper conditions. In the preferred embodiment, the burst avoidance process may be invoked by a port upon receipt of a BPDU if: (a) the receiving port is a root port in the forwarding state that is transitioning to the designated role as part of a topology change, and (b) the port has received current (not aged out) information from the Designated bridge, i.e, infoIs has the “received” value. However, the burst avoidance process may not be invoked while any port of a bridge is attempting to propagate a topology change notification through the network, i.e., the tcProp should not be set, and may not be invoked if the port from which the BPDU is received is attempting to become a designated bridge, i.e., the proposal flag of the received BPDU should not be set. Under the preceding conditions, the switch 300 of the preferred embodiment is adapted to delay the time to transmit a BPDU in the direction of the link failure by suppressing the time at which the newInfo is set. That is, the newInfo, which is a boolean variable used to signal when a BPDU with changed topology information is to be transmitted, is not set TRUE in accordance with the PSIM of the prior art. Instead, the switch 300 sets the newInfo to TRUE after a period of time not to exceed a burstAvoidDelay, the burstAvoidDelay not to exceed the Hello time. Assuming the Hello time is set to a default value of two seconds, the BC switch 300 may delay the transmission of the BPDU by as much as two seconds.
[0032] In some embodiments, the bust control processing of the preferred embodiment is implemented as an improvement to the Port Information State Machine (PISM) illustrated in FIG. 4 , particularly the functionality associated with UPDATE state 402 as well as the conditions associated with the transition from the CURRENT state 404 to the UPDATE state 402 . The improved PISM is referred to herein as the Burst Control State Machine (BCSM) 500 , which is illustrated in FIG. 5 .
[0033] The BCSM 500 in the preferred embodiment includes two update states for state variables associated with the transmission of BPDUs from the BC switch 300 , namely an the UPDATE state 402 consistent with the RSTP standard as well as an UPDATE_BURST_AVOIDANCE state 502 . The UPDATE_BURST_AVOIDANCE state 502 and the UPDATE state 402 represent alternative states, i.e., only one of the two being implemented at any given time. Which of the two states being implemented is dictated a burstAvoid parameter whose value is determined as a function of the burst control conditions discussed above. The BCSM 500 in the preferred embodiment further includes the following: DISABLED state 506 , AGED state 508 , SUPERIOR_DESIGNATED state 510 , REPEATED_DESIGNATED state 512 , INTERIOR_DESIGNATED state 514 , NOT_DESIGNATED state 516 , OTHER state 518 , CURRENT state 520 , and RECEIVE state 522 . The states 506 , 508 , 510 , 512 , 514 , 516 , 518 , 520 , 522 are defined in the RSTP standard and are well understood by those skilled in the art.
[0034] The UPDATE state 402 illustrated in FIG. 6 employed in the present invention (see FIG. 5 ) is substantially the same as the UPDATE state of the prior art PISM (see FIG. 4 ). In particular, the BCSM 500 in the UPDATE state 402 is adapted to define or redefine the following system parameters set forth in the RSTP standard: proposing=proposed=FALSE; agreed=agreed && betterorsameInfo( ) where betterorsameInfo( ) is TRUE or FALSE depending on the value of the function argument, the infoIs value, and whether the MPV is better or the same as the PPV; synced=synced && agreed; PortPriority=DesignatedPriority; PortTimes=DesignatedTimes; updtInfo=FALSE; infoIs=Mine; and newInfo=TRUE, each of these system parameters and functions being defined in the RSTP standard.
[0035] In contrast to the prior art, the BCSM 500 is adapted to transition from the CURRENT state 520 to the UPDATE state 402 if the selected && uptdInfo && !burstAvoid evaluate to TRUE. While the selected && uptdInfo are defined in the prior art, burstAvoid is a new parameter introduced to regulate which of the two update states is to be executed. In the preferred embodiment, burstAvoid is false unless the burst control conditions discussed below are satisfied, that is: TABLE-US-00001 If (burstAvoidanceControl) {If (infoIs==RECEIVED) {If (selectedRole==DESIGNATED) {If ((role==ROOT) && (state==FORWARDING)) {If (proposing==FALSE) {If (tcProp==FALSE) {burstAvoid=true; }}}}}} where burstAvoidanceControl is a user-defined parameter set equal to TRUE to configure burst control in the preferred embodiment, or set equal to FALSE if burst control is to be disabled. The default value of the burstAvoidanceControl is TRUE in the preferred embodiment, and the default value of burstAvoidanceControl is FALSE signifying that the instant protocol has not been activated by default.
[0036] In the alternative to the prior art UPDATE state 402 , the preferred embodiment is enabled to invoke the UPDATE_BURST_AVOIDANCE state 502 if selected && uptdInfo && burstAvoid evaluate to TRUE. As illustrated in FIG. 7 , the UPDATE_BURST_AVOIDANCE state 502 is adapted to define or redefine the following system parameters set forth in the RSTP standard: proposing=proposed=FALSE; agreed=agreed && betterorsameInfo( ) where betterorsameInfo( ) is TRUE or FALSE depending on the value of the function argument, the infoIs value, and whether the MPV is better or the same as the PPV; synced=synced && agreed; PortPriority=DesignatedPriority; PortTimes=DesignatedTimes; updtInfo=FALSE; and infoIs=Mine. In contrast to the UPDATE state 402 of the prior art, the BCSM 500 does not set newInfo=TRUE, thereby preventing the BCSM 500 from immediately transmitting a BPDU in the direction of the link failure. As a consequence, any BPDU transmitted from the associated port is delay a maximum of two seconds in accordance with the Hello time.
[0037] As one skilled in the art will appreciate, burstAvoid is a port parameter, defined with respect to each switch port, authorizing the burst avoidance protocol to be activated on the associated port. The burstAvoid parameter may be initially set to FALSE in the DISABLED state 506 of the BCSM 500 which is otherwise identical to the Port Information State Machine illustrated in FIG. 4 . The value of burstAvoid may be set to TRUE, if applicable, in a function referred to herein as burstAvoidFunc( )) invoked in the RECEIVE state 802 of Port Role Selection state machine set forth in the RSTP standard. As illustrated in Port Role Selection state machine 800 of FIG. 8 , the burstAvoidFunc( ) is preferably executed concurrently with the clearReselectTree( ) the updtRolesTree( ) and the setSelectedTree( )) functions. The burstAvoid parameter may be set back to FALSE, if applicable, in a function referred to herein as clearBurstAvoidFunc( ) upon conclusion of the RECEIVE state 802 . As stated above, the burstAvoidFunc( ) procedure is performed on the port that receives the incoming BPDU if the received BPDU does not contain TC flag set or a proposal flag set, while the clearburstAvoidFunc( ) procedure clears all burstAvoid parameters on each of the plurality of ports of the BC switch 300 .
[0038] As the burst avoidance protocol of the preferred embodiment is activated, the fact that the newInfo parameter is not set immediately means that the BPDU is delayed utmost of two seconds in accordance with the hello timer. The fact that proposing is not set on the port that has received the BPDU also means that the protocol applies only if there is no Alternate port on that bridge. An Alternate port, which is becoming Root port, triggers REROOT, meaning that any Recent Root port must become Discarding and needs to send a proposal immediately to become Designated Forwarding again. Also if tcProp is set on the port that receives the BPDU, TC BPDUs should be sent from the port and the burst avoidance protocol not activated.
[0039] In the preferred embodiment, a two seconds delay is not induced in the complete spanning tree computation. The actual delay, referred to as the burstAvoiddelay, is preferably the delay associated with the elapse time necessary for the TC BPDU to propagate to the alternate bridge 111 and for the alternate bridge to send a BPDU back to the bridge that initially detected the failure and believed itself to be the new Root bridge.
[0040] One skilled in the art will appreciate that the BCSM 500 of the preferred embodiment is backward compatible, i.e., the burst avoidance protocol applies on an RSTP port even if that RSTP port is facing an conventional spanning tree protocol (STP) port.
[0041] Illustrated in FIG. 9 is an RSTP message exchange between the BC bridges of a data communications network. For convenience, the RSTP message exchange represented corresponds to a data communications network 100 having the ring topology illustrated in FIG. 1 , where each of the bridges 100 - 120 is a burst control switch adapted to execute the burst avoidance protocol of the preferred embodiment. As with the previous example described above, failure of any of the communications links with the root bridge 101 breaks an active transmission path in the spanning tree. If and when the communications link 130 A fails—indicated by the dashed line 902 —BC bridge 120 losses its root bridge and initiates a topology change to re-establish a spanning tree within the BC bridges 100 - 120 . The BC bridge 120 immediately sends a BPDU 904 declaring that it is the new root bridge from port 120 A.
[0042] Upon receipt of the BPDU 904 , BC bridge 119 compares 905 the MPV with its own PPV and determines that it has a better priority vector than BC bridge 120 . Port 119 B of BC bridge 119 immediately transitions from a “Root Forwarding” to a “Designated Forwarding” port. Although BC bridge 119 proceeds to transmit a BPDU 906 declaring that bridge 119 is the new root bridge from port 119 A, the bridge 119 refrains from transmitting a BPDU from port 119 A if the burst control conditions discussed above apply. That is, port 119 A withholds transmission of BPDU 206 sent in the prior art (see FIG. 2 ) assuming that: (a) port 119 A was a Root port in the Forwarding state prior to the failure of communications link 130 A, (b) port 119 A would transition to the Designated role after the spanning tree topology converges, (c) the forwarding information at port 119 B has not aged out, i.e., infoIs is equal to “received,” (d) the tcProp flag of the received BPDU had not been set, (e) the proposal flag of the received BPDU had not been set, and (f) the user had enabled the burst avoidance protocol by setting burstAvoidanceControl equal to TRUE.
[0043] While scenario described immediately above gives rise to a temporary situation in which there are two “Designated Forwarding” ports face-to-face—namely port 120 A of BC bridge 120 and port 119 B of BC bridge 6 —one skilled in the art will appreciate that there is no detrimental impact on forwarding operations since those two ports were already in the Forwarding state before.
[0044] Upon receipt of the BPDU 906 , BC bridge 118 compares 907 the received MPV with its own PPV, determines that it has a better priority vector than BC bridge 119 , transitions from a “Root Forwarding” port to a “Designated Forwarding” port, transmit a BPDU 908 declaring that bridge 118 is the new root bridge, and withholds transmitting a BPDU to BC bridge 119 advertising that it is the new root bridge. Similar, each of the BC bridges 117 - 112 conducts the priority vector comparison 907 , 909 , 911 , 913 , 915 , 917 upon receipt of the a BPDU on the interface in the direction of the link failure 902 , determines that it has a superior priority vector, and forwards a BPDU advertising it is the new root bridge. The sequence of BPDUs transmitted away from the link failure continues until a BPDU 913 from BC bridge 112 is received by the alternate port 111 B of BC bridge 111 .
[0045] Upon recognition 919 of its superior priority vector, port 111 B of BC bridge 111 attempts transition to a Designated role and Forwarding state, i.e., a “Designated Forwarding” port. As such, BC bridge 111 transmits a “proposal” BPDU 910 to BC bridge 112 . Port 112 A of BC bridge 112 —which is currently a “Designated Forwarding” port—immediately assumes a Root role and Forwarding state, i.e., a “Root Forwarding” port. In accordance with RSTP standard, BC bridge 112 sends a “proposal” BPDU 912 to BC bridge 113 , and each of the successive BC bridges 113 - 120 forwards a “proposal” BPDU 916 , 918 , 920 , 924 , 926 until the “proposal” BPDU is received by the last BC bridge 120 . The receiving port of each of the BC bridges 113 - 120 from a “Designated Forwarding” port to a “Root Forwarding.” One skilled in the art will appreciate that BC bridges 112 - 120 generally respond to the “proposal” BPDUs with “agreement” BPDUs (not shown) in accordance with the RSTP standard.
[0046] The spanning tree has converged upon receipt of the “proposal” BPDU 926 at BC bridge 120 and transmission of the associated “agreement” BPDU from BC bridge 120 . As one skilled in the art will appreciate, the final spanning tree topology is reached without the excessive number of BPDUs exchanged in the exemplary situation illustrated in FIG. 2 . For example, the number of BPDUs transmitted to port 120 B of BC bridge 120 is one, in contrast to the eleven BPDUs transmitted to port 120 B of the prior art bridge 120 discussed in reference to FIG. 2 above. In addition to the reduced bandwidth requirements, the preferred embodiment of the present invention also significantly reduces the chance of any bridge reaching the burst limiter, i.e., txHoldCount, thereby reducing the delay necessary for the spanning tree to converge in a single failure scenario like that discussed above.
[0047] 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.
[0048] 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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An apparatus and method for controlling bridge protocol data unit bursts is disclosed. The invention in the preferred embodiment is a switching device with a port enabled with a link management protocol and a burst control state machine. The burst control state machine is adapted to receive BPDUs and, under certain conditions, delay responding with its own BPDU falsely advertising itself as the new root bridge. The delay is preferably long enough to enable another bridge to identity the true root bridge. The delay, e.g., a burst control delay, is preferably equal to or less than a Hello time timer value generally defined to be 2 seconds in a Rapid Spanning Tree Protocol standard, for example.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This invention is based upon and claims the benefit of priority from U.S. Provisional Application Ser. No. 60/934,896 filed the 15th of Jun., 2007.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to the field of flashing the perimeters and penetrations of flat roofing systems whereby a pliable waterproofing membrane is used to cover the roof and then folded in a specified manner in order to protect the fasteners and further waterproof the building.
[0006] 2. Background
[0007] In the field of flat or low-slope roof installation, the use of pliable reinforced membranes to waterproof buildings is becoming ever more popular due to their ease of use and many advantages. However, as with any roofing system, there are difficulties and complications that arise when one considers how to waterproof the perimeter of a building (at any vertical junctures such as a wall or the flat edge of the roof) as well as any projections through and above the roof. The primary difficulty arises due to the seams and vertical junctures, which create a need to terminate the membrane in a completely watertight fashion.
[0008] This difficulty of waterproofing membrane terminations in the past has been dealt with by several methods, primarily by use of a two piece membrane flashing system coupled with pre-formed sheet metal parts. Typically, on a flat roof with a parapet wall, the membrane on the horizontal part of the roof is cut at the junction between the wall and the roof. This membrane is then fastened by the same means as the rest of the flat part of the roof. Then, a separate piece of membrane is attached to the wall by means of termination bar (typically a pre-formed piece of sheet metal) and the uppermost junction of the termination bar with the wall is sealed with a bead of watertight sealant. The loose membrane below the location of the termination bar is then folded at the wall-roof junction and adhered (typically by chemical or thermal means) to the first piece of membrane on the horizontal roof, thereby covering and sealing in the fasteners.
[0009] Curbs (rectangular projections through a roof) are typically flashed in a very similar manner, requiring more fasteners than on a flat portion of the roof in order to sufficiently waterproof the penetration. There is also a pre-formed corner that is designed to fit over the corners of these penetrations. They are made of the same base material as the membrane used on the roof and are chemically compatible with said membrane. The membrane around the curb has to be fastened in the same manner as the rest of the roofing membrane and then have another separate piece of membrane covering the vertical surfaces of the curb and also covering the fasteners around its perimeter in order to protect and waterproof them.
[0010] The difficulty with using two pieces of membrane to flash the roof lies particularly in the increased labor involved. The membrane must first be fastened to the roof itself. Mechanical fasteners are typically placed from six inches to eighteen inches apart, which can amount to a considerable number of fasteners on the perimeter and penetrations of a large building. Chemical adherence (typically a specialized type of glue or tape) can be very time consuming as well. After fastening the membrane to the substrate that is already attached to the roof, a separate piece of membrane must be cut and terminated at one end then also welded to the membrane. This multi-step process requires intensive labor and time. In addition, it can be easy to make an error in this complicated process. Any portion of the membrane that does not create a perfect seal will allow moisture underneath the membrane, potentially leaking and causing damage to the substrate and roof deck.
[0011] It is the goal of the system and accompanying devices to simplify the process of installing membrane roofing on flat roofs. To be able to use only a single piece membrane flashing for edges and curbs will not only make the roof installation process simpler and less time consuming but will also decrease the likelihood of water penetrating through to the substrate and, in turn, make a more waterproof roofing system with high versatility and ease of installation. Furthermore, the system attempts to reduce potential water penetration by use of ridges in the devices and compression of the membrane at fastening points. This system will retain a high level of wind uplift resistance and maintain strength at all fastening points.
[0012] There have been previous attempts at solving some, but not all, of the above listed problems and difficulties. U.S. Pat. No. 5,619,827 attempted to solve the problem of waterproofing a roof at the edge by use of interlocking sheet metal assemblies that serve to anchor the roof as well as waterproof it. However, this system only works for situations where the roof is entirely horizontal and there is no vertical wall. In addition, it does not appear to make the roofing installation process much simpler than the current methods. This method does make use of a non-penetrative means of anchoring the membrane to the roof, which increases waterproofing capabilities simply in the fact that no hole is made in the roofing membrane. There does appear to be a question of how well the system can anchor the membrane down sufficiently, leaving it open to pulling due to thermal shrinkage and detachment due to high winds.
[0013] The most common fastening method for membranes is the stress plate, as described in U.S. Pat. No. 4,787,188. The plate's primary purpose is to clamp the membrane to the roof deck. In its most used form, the stress plate is circular, with a centrally located fastening hole, which accepts a screw or other mechanical fastener. The plate has two sets of concentric ridges. It is placed on top of the membrane and a fastener extends through the plate and to the roof deck. The prongs inhibit motion of the membrane in relation to the plate. However, since the plate is not watertight, it has to be overlapped with a separate portion of membrane, heat or chemically welded to cover the plate and fastener and waterproof them. For the inner (non-perimeter) portion of the roof, this is the most common and efficient method of fastening membrane. However, due to the lack of a seam and the need for more fasteners at the perimeter (as well as at curbs and other penetrations), there is desired a better method of waterproofing a roof and securing it to the building structure.
SUMMARY OF THE INVENTION
[0014] The system described herein is based on the idea of using standard fastening means of attaching a roofing membrane to a roof structure in the interior of a flat roof and using the specialized means herein to fasten the membrane at the perimeter of the roof, as well as at the curbs and other penetrations (areas where flashing is required). At the perimeter (either at a wall rising above the level of the roof or at the vertical portion of the building beneath the level of the roof), a longer than normal length of membrane is taken and folded over to form a folded seam. The invention encompasses a series of specialized devices that can be used to anchor the folded seam of roofing membrane to the deck, wall or lower wall, whereby the excess membrane is then folded up and over the fastening device then terminated by standard methods. The primary goal and intent of this invention is to replace the method of flashing vertical junctures with two pieces of membrane and to instead simplify the process by means of a single piece membrane flashing. Methods and devices disclosed herein can be used as part of the total system or can be combined with any number of industry standard methods and devices.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a top view of one possible embodiment in an ellipsoidal shape of the first device ( 5 ) that is described. It includes multiple fastening points ( 13 ) and a single raised ridge ( 17 ) on the upper plate ( 15 ) and a single raised ridge ( 16 ) on the lower plate ( 14 ). The upper plate ( 15 ) is designed to fit securely over the lower plate ( 14 ) and a fastener would pass through the fastening points ( 13 ) in both the upper plate ( 15 ) and the lower plate ( 14 ).
[0016] FIG. 2 is a top view of an alternate embodiment in a rectangular shape of the first device ( 5 ) that is described. It includes multiple fastening points ( 13 ) and a single raised ridge ( 17 ) on the upper plate ( 15 ) and a single raised ridge ( 16 ) on the lower plate ( 14 ). The upper plate ( 15 ) is designed to fit securely over the lower plate ( 14 ) and a fastener would pass through the fastening points ( 13 ) in both the upper plate ( 15 ) and the lower plate ( 14 ).
[0017] FIG. 3 is a top view of another alternate embodiment in a circular shape of the first device ( 5 ) that is described. It includes multiple fastening points ( 13 ) and a duality of raised ridges ( 17 ) on the upper plate ( 15 ) and a duality of raised ridges ( 16 ) on the lower plate ( 14 ). The upper plate ( 15 ) is designed to fit securely over the lower plate ( 14 ) and a fastener would pass through the fastening points ( 13 ) in both the upper plate ( 15 ) and the lower plate ( 14 ).
[0018] FIG. 4 is a top view of another alternate embodiment in a square shape of the first device ( 5 ) that is described. It includes a single fastening point ( 13 ) and a duality of raised ridges ( 17 ) on the upper plate ( 15 ) and a duality of raised ridges ( 16 ) on the lower plate ( 14 ). The upper plate ( 15 ) is designed to fit securely over the lower plate ( 14 ) and a fastener would pass through the fastening points ( 13 ) in both the upper plate ( 15 ) and the lower plate ( 14 ).
[0019] FIG. 5 is a side cutout view of the first device ( 5 ) that is described showing the device ( 5 ) in use. The device ( 5 ) is mounted on the roof substrate ( 2 ) with the folded portion of the membrane ( 21 ) placed between the upper plate ( 14 ) and the lower plate ( 15 ) and secured by use of a mechanical fastener ( 8 ) passing through the folded portion of the membrane ( 21 ) as well as both plates ( 14 and 15 ) by use of the fastening points ( 13 ). The ridges ( 16 ) on the upper plate ( 14 ) cooperate with the ridges ( 17 ) on the lower plate ( 15 ). The excess membrane ( 20 ) is folded up and onto the wall ( 3 ), whereby it is terminated by use of termination bar ( 10 ) fastened with a mechanical fastener ( 11 ) and sealant ( 12 ) at the upper point of the termination bar ( 10 ).
[0020] FIG. 6 is a side cutout view of the first device ( 5 ) that is described showing the device ( 5 ) in use. The device ( 5 ) is mounted on the wall ( 3 ) which extends above the level of the roof substrate ( 2 ) with the folded portion of the membrane ( 21 ) placed between the upper plate ( 14 ) and the lower plate ( 15 ) and secured by use of a mechanical fastener ( 8 ) passing through the folded portion of the membrane ( 21 ) as well as both plates ( 14 and 15 ) by use of the fastening points ( 13 ). The ridges ( 16 ) on the upper plate ( 14 ) cooperate with the ridges ( 17 ) on the lower plate ( 15 ). The excess membrane ( 20 ) is folded up and onto the wall ( 3 ) at a point higher than the vertical level of the device ( 5 ), whereby it is terminated by use of termination bar ( 10 ) fastened with a mechanical fastener ( 11 ) and sealant ( 12 ) at the upper point of the termination bar ( 10 ).
[0021] FIG. 7 is an isometric view in very simplistic form of the second device ( 6 ) that is described. The fastening points ( 13 ) and the multiple bends ( 19 ) in the body of the device ( 6 ) are depicted. The top portion ( 23 ) and the bottom portion ( 24 ) are indicated. The curl in the device ( 6 ) at the bottommost portion ( 24 ) is curved.
[0022] FIG. 8 is a side cutout view of a non-penetrative use of the second device ( 6 and as described in FIG. 7 ). The device ( 6 ) is mounted on the wall ( 3 ) which extends above the level of the roof substrate ( 2 ) with the folded portion of the membrane ( 21 ) placed beneath the device's ( 6 ) lower end ( 24 ) and secured by use of a mechanical fastener ( 8 ) passing through a fastening point ( 13 ) near the upper end ( 23 ) of the device ( 6 ). The multiple bends ( 19 ) in the device ( 6 ) enable compression of the folded portion of the membrane ( 21 ). The excess membrane ( 20 ) is folded up and onto the wall ( 3 ) at a point higher than the vertical level of the device ( 6 ), whereby it is terminated by use of termination bar ( 10 ) fastened with a mechanical fastener ( 11 ) and sealant ( 12 ) at the upper point of the termination bar ( 10 ).
[0023] FIG. 9 is an isometric view of an alternate embodiment of the second device ( 6 ) that is described. The fastening points ( 13 ) and the multiple bends ( 19 ) in the body of the device ( 6 ) are depicted. The top portion ( 23 ) and the bottom portion ( 24 ) are indicated. The bend in the device ( 6 ) at the bottommost portion ( 24 ) is curved.
[0024] FIG. 10 is an isometric view of an alternate and more complicated embodiment of the second device ( 6 ) that is described. The fastening points ( 13 ) and the multiple bends ( 19 ) in the body of the device ( 6 ) are depicted. The top portion ( 23 ) and the bottom portion ( 24 ) are indicated.
[0025] FIG. 11 is an isometric view of the third device ( 7 ) that is described, embodied as a single piece device. It depicts the fastening points ( 13 ), the hinge device ( 31 ), the ridges ( 34 ) on the upper section ( 32 ), the ridges ( 35 ) on the lower section ( 33 ), and the possible fastening point ( 36 ) on the lower section ( 33 ).
[0026] FIG. 12 is an isometric view of the third device ( 7 ) that is described, embodied alternately as a two piece device. It depicts the fastening points ( 13 ), the hinge device ( 31 ), the ridges ( 34 ) on the upper section ( 32 ), the ridges ( 35 ) on the lower section ( 33 ), and the possible fastening point ( 36 ) on the lower section ( 33 ).
[0027] FIG. 13 is a side cutout view of the third device ( 7 ) that is described, depicting it in one possible embodiment mounted at the roof substrate ( 2 ) and wall ( 3 ) juncture. A fastener ( 8 ) can, though not necessary, be placed through the optional fastening point ( 36 ) and through to the substrate ( 2 ). The folded portion of membrane ( 21 ) is placed between the upper section ( 32 ) and the lower section ( 33 ) of the device ( 7 ). Another fastener ( 8 ) is placed through the fastening point ( 13 ), thus compressing the folded portion of the membrane ( 21 ). The ridges ( 34 ) on the upper section ( 32 ) and the ridges ( 35 ) on the lower section ( 33 ) help to compress the folded portion of the membrane ( 21 ) and prevent any pull from the area of the main roof's membrane ( 1 ). The excess membrane ( 20 ) is folded up and onto the wall ( 3 ) at a point higher than the vertical level of the device ( 6 ), whereby it is terminated by use of termination bar ( 10 ) fastened with a mechanical fastener ( 11 ) and sealant ( 12 ) at the upper point of the termination bar ( 10 ).
DETAILED DESCRIPTION OF THE INVENTION
[0028] The primary purpose of this invention is to create a superior waterproofing system for use with membrane roofing material for flat and low slope roofing situations. This purpose is achieved through use of a particular method coupled with devices that are designed specifically to hold a folded piece of membrane to a roof deck or vertical juncture. There are the following devices to be described and then a discussion will be made on the method of installation following and incorporated into a detailed description of each device.
[0029] When referring to the folded portion of the membrane, it is intended to describe that part of the membrane at the very perimeter of the building which is laid flat on the roof then folded back over such that the upper surface of the membrane is put into contact with itself and the lower surface of the membrane is exposed. The folded portion of the membrane describes the point of folding and a subsequent portion thereof where the parts of the membrane are in contact.
[0030] The first device (# 5 when referring to its entirety in the drawings and depicted in FIGS. 1 through 6 ), is similar in some ways to the standard plate used to secure membrane to the deck of a roof. However, it differs in several key features. The invention hereby disclosed as the first device is of two separate objects, both in the basic form of either a circular or a polygonal shape with minimal height. It would ideally be fabricated from a fairly rigid material.
[0031] Within the interior of the body of the upper plate, there are one or more raised ridge(s) conforming to the same shape of the outer perimeter's shape and proportions, though of a smaller size. The shape of the ridge(s) is closed such that it is continuous and such that there is no beginning or ending point. In the interior of all ridges on the plate and preferably centered on at least one axis, there is a hole extending through the entirety of the plate through which a fastener can be placed during installation. There may be one or more of such holes depending on current needs.
[0032] The body of the lower plate is of slightly smaller proportions than the upper plate such that the underside of the upper plate conforms to the top side of the lower plate with clearance for the folded portion of the membrane to be placed between the two surfaces. It incorporates the same features as the upper plate, including one or more fastening hole(s) located at point(s) such that when the upper plate is placed on top of the lower plate, the fastening point(s) are both at the same locations relative to an axis set perpendicular through the center of said fastening point(s).
[0033] The purpose of the upper and lower proportionally sized plates is that the folded membrane can be placed between them and, upon placing appropriate fastener(s) through the fastening point(s), the membrane is compressed. By this compression, the membrane cannot move in any direction, thus held securely in place both by the fastener(s) and the friction between the upper and lower plates and the folded portion of the membrane. The ridges on both the upper and lower plates serve not only to further increase the amount of friction and holding power but also to prevent the movement of water between the interior surfaces of the folded layers of the membrane and to also prevent water from reaching the fastener. It is also possible to incorporate a raised semi-conical surface raised on an axis perpendicular to and centered around the fastening point(s) with the fastening point(s) at the highest point of the raised conical surface.
[0034] Once the membrane has been installed over the interior portions of the roof, it will have to be terminated and flashed at the perimeters in order to properly waterproof these locations. The lower plate of the first device will lie beneath the folded portion of the membrane and may or may not be fastened to the substrate depending on whether there is one or more fastening points. If there is only one fastening point, the lower plate will lay loose until the upper plate is fastened, whereby the fastener will pass through both the upper and lower plates, securing both plates as well as the membrane. If there is more than one fastening point, the lower plate can be fastened first to the substrate by passing a fastener through any one or more of the fastening points. Then, one would follow by placing the folded portion of the membrane on the top surface of the lower plate and placing the upper plate on the topside of the folded portion of the membrane, whereas the lower surface of the upper plate is in contact with the folded portion of the membrane. At this point, one would place one or more fastener(s) through the fastening point(s) of the upper plate, the folded portion of the membrane, the fastening point(s) of the lower plate, and through to the substrate, thus securing the compressed plates and folded membrane to the substrate or wall.
[0035] Once the folded portion of the membrane has been secured, the purpose of the next step is to waterproof the locations where the fastening and penetration of the membrane has occurred. There exists a single layer of excess membrane extending past the location of the device and generally located toward the direction of the roof's interior. This excess membrane is then folded away from the main roof and terminated by standard means (typically by securing with termination bar and placing a bead of sealant across the surface) either up a vertical wall which extends up above the level of the roof or down a vertical wall below the level of the roof. This process seals in the device in an envelope of membrane, thus protecting it from the elements. One would use a plurality of the devices with the actual quantity and spacing dependant on many factors including, but not limited to, the size of the building, wind uplift resistance requirements, and type and thickness of the membrane being used.
[0036] The second device (# 6 when referring to its entirety in the drawings and depicted in FIGS. 7 through 10 ) is designed to be used as a pinching mechanism in either deck or wall mount situations with the membrane folded and fastened, followed with the excess membrane folded up and over the device to then be terminated by standard means. The device is, however, of a single nature, being made of only one part. It is fabricated from a rigid material, yet must also have ductile strength so as to be capable of bending, though, due to the rigidity, the ability to bend must be limited and only under extreme pressure. The strength in the device's nature is in its ability to compress and, therefore, it must be ductile, yet strong.
[0037] The overall shape of the pinching device is that of a flat piece of material into which multiple bends, all along the same axis, have been made. The piece of material can be a long and continuous piece, such that the height is a very small fraction of the overall length, or it can be of a size whereby the height and width are nearly equal. Ideally, one would envision a length convenient to transport yet long enough to minimize seams between pieces. It is possible, though not recommended, for the measurement of the length to be less than or equal to the measurement of the height if one desired many smaller pieces to be spaced some distance apart from each other linearly at the roof/wall juncture. There are a plurality of bends with the purpose of all bends together to provide compression at both the top end and the bottom end of the device towards and into, though not penetrating, the folded portion of the membrane at the bottom end of the device and the wall or substrate. The bends create a shape whereby when the device makes contact with the substrate or wall with the top end, then the device's body goes back out in the opposite direction of the substrate or wall and then back again towards the direction of the substrate or wall and makes contact once more with the bottom end. The bottom end can be fabricated as curved. This will prevent the material from penetrating the membrane where it folds up onto the wall. The bends may be made in many variations such that the same purpose is achieved and the process of the device's body being made to recede away from the membrane and then back may occur more than a single time. The device also consists of a single fastening point or a plurality of fastening points that are located at the topmost portion of the device such that the first unbent portion will be pressed firm against the substrate or wall at the point at which it is fastened. It would follow then, that the lowest portion of the device would compress the folded portion of the membrane at the point(s) where the membrane and the device come into contact.
[0038] The usage of this pinching device as described above would be very similar to the plate device described in the previous paragraphs. The membrane would be fastened to the main interior portions of the roof. At the juncture of the edge of the roof and the wall (can be used to fasten on walls either rising above the surface of the roof or below the surface of the roof), the membrane would be folded back towards the direction of the interior of the roof. Then, the device would be attached to either the substrate or the wall via mechanical fastener(s) through the fastening point(s). The number of fasteners would be dependant on many factors including, but not limited to, the size of the roof, wind uplift resistance requirements, and the type and size of membrane being used. Once the device is fastened, the excess membrane would then be folded up over the device and terminated on the wall, above the height level of the device, by standard termination means as previously described. One could either use a plurality of shorter length devices with distances between them or a minimal number of longer pieces with seams overlapping.
[0039] The third device (# 7 when referring to its entirety in the drawings and depicted in FIGS. 11 through 13 ) to be described is designed to also have a gripping force on the membrane, though it incorporates a hinge-like mechanism to achieve this. The device can be embodied as either a two piece design or a single piece design. It is designed to be installed on the very edge of the roof, at the juncture between the roof and the upper wall and to use similar fastening methods as described previously. It is desired that the fabricated device should be of a material that is very rigid.
[0040] The device itself can have multiple designs, though centered around a single piece embodiment and a dual piece embodiment. The preferred embodiment of a singular piece design is described firstly. The device is comprised of essentially two pieces joined together by a hinge-like device which not only serves to hold the two pieces together into a single piece, but also serves to allow rotational movement about the axis whereas the two pieces are joined. It is also possible to make the same device but in a two piece design, whereas the upper and lower sections are separate but can be placed together in a non-permanent fashion in order to act as a hinge and, upon fastening, will act as a single piece device with a hinge.
[0041] The design of the upper and lower pieces of the device is of a piece of material that has been bent into an angle near that of a right angle (minimal variation in the direction of obtuseness is possible though the angle should not be acute in nature). Into the bottom section of the angled material of the lower piece of the device, there would be either one or a multiplicity of raised ridges. Into the bottom section of the angled material of the upper piece of the device, there would be the same number and type of raised surfaces, though they would be of either the same size or larger than those ridges of the lower piece, such that the upper piece and the lower piece would cooperate. The upper section of the both the upper and lower pieces of the device would ideally be flat, though their shape would not be of issue, so long as the upper and lower pieces cooperate with each other and conform to some degree to the wall to which they will be attached. The device in its entirety would be generally of an “L” shape with a hinge device at the very topmost extent of the “L.” It could be constructed in a fashion whereby the device is taller than it is wide or it could be designed as a very long piece.
[0042] Into the upper section of both the upper and lower pieces of the device, there would be a fastening point such that a mechanical fastener could extend through the upper piece, the lower piece and then into the wall. There can be one single fastening point on a device of very short length or there could be a plurality of fastening points on a device of longer length. It is also possible to have a fastening point on the lower piece of the device such that it could be fastened prior to the mechanical fastener being placed through both the upper piece and the lower piece.
[0043] The method of installation for the hinge device is quite similar to that of the previously described devices but would differ in details. The device would be situated such that it conforms to the angle between a wall extending above the level of a roof. If there is a fastening point present in the lower piece of the device, one would first place a fastener through said fastening point, thus anchoring the lower piece of the device to the substrate of the roof. If no fastening point is present on the lower piece of the device, then one would lay the device loosely at the point where the wall and roof substrate meet. The membrane would first be fastened on the interior portions of the roof then at the wall/roof juncture, the membrane would be folded such that the endpoint of the membrane reached in the same direction of the interior of the roof. The folded portion of the membrane would then be placed between the upper piece and the lower piece of the device. One would then place a fastener through the fastening points of the upper piece and the lower piece such that it extended into the wall, thereby compressing the membrane and holding it secure in a non-penetrative fashion between the lower sections of the upper piece and lower piece of the device.
[0044] It is also possible to place the folded portion of the membrane such that it lies between the upper piece and lower piece of the device and the fastener penetrates the membrane, thus holding it even more secure. This procedure would be optional and would not change the function of the entire system in any significant way.
[0045] Once the folded portion of the membrane has been secured and the device has been properly fastened, there exists an excess single layer of membrane that remains unsecured. This layer of membrane will then be folded up towards the uppermost portion of the wall and terminated by standard methods.
[0046] It is possible for all of the devices that have been previously described to also be suited for a situation where there is no vertical wall rising above the level of the roof. In the situation of a roof that ends without said wall, one could employ the abovementioned devices by attaching them to that part of the wall which extends below the level of the roof. In some cases, one may be required to mount them upside down from how they were previously described. Any such person who is skilled in the art will find multiple methods and adaptations for these methods and devices though all center around a central basic idea.
[0047] The previous paragraphs have detailed the invention and how it applies to the perimeters of a roof but there must be mention made as to how rectangular roof penetrations (which must also be flashed) are handled. The typical roof penetration would be treated as a wall that extends up above the surface of a roof and the devices, as previously described, would be fastened accordingly with the membrane also folded up and over the device, then terminated by standard means up the wall of the curb. The corners of the penetration could be flashed by standard means (typically with pre-formed corners made of a material that is compatible with the membrane), ensuring that the folded portion of the membrane is welded together so as to seal in the fasteners and also to prevent water from penetrating and reaching the underside of the membrane. Round roof penetrations (i.e. pipes, etc.) could also be handled by standard methods.
[0048] It is the intention of the inventor to introduce these devices and method in order that the practitioner of the roofing art will be able to utilize them accordingly and still be capable of adapting them to each job. With the wide variations in today's buildings, it is necessary to be able to change while still maintaining the spirit of the invention.
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The purpose of this invention is to decrease labor involved in waterproofing via flashing and termination of a pliable membrane roofing system at its perimeters and vertical junctures. As opposed to a standard two piece membrane flashing, the invention provides for a single piece of membrane to be used. The single piece of membrane would be taken from that which has already been installed on the flat portion of the roof. The loose section would be folded and the folded section would be anchored to the roof or vertical junctures. The piece now left loose would be folded over the anchoring device and terminated on the roof or vertical juncture. There are 3 devices disclosed which are intended to serve the purpose of anchoring the folded portion of roof. Elimination of the two piece flashing will greatly decrease the labor involved in roof installation with no loss in roof performance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. aplication Ser. No. 10/018,960, filed Dec. 21, 2004 and titled “RANGE FINDER” (Attorney Docket NO. 119.003US04), which is a divisional application of U.S. application Ser. No. 10/804,372, filed Mar. 19, 2004 and titled “RANGE FINDER” (Attorney Docket No. 119.003US03) (abandoned) which is a continuation application of U.S. application Ser. No. 10/641,169 filed Aug. 14, 2003 and titled “RANGE FINDER,” (Attorney Docket No. 119.003US02) all of which are herein incorporated by reference. Further, U.S. Patent No. 119.003US02 issued Jan. 24, 2006 as U.S. Pat. No. 6,988,351 is a continuation application of U.S. application Ser. No. 10/090,333, filed Mar. 4, 2002, issued Sep. 9, 2003 as U.S. Pat. No. 6,615,531 and titled “RANGE FINDER,” (Attorney Docket No. 119.003US01) which is herein incorporated by reference and claimed in priority.
TECHNICAL FIELD
[0002] The present invention relates generally to range finders and in particular range finders for hunting applications.
BACKGROUND
[0003] Range finders can be a useful tool when hunting for game. A ranger finder conveys the distance to an object (game target). This information is helpful to a hunter because it allows a hunter to determine if the target is beyond the range of a firearm or bow. Knowing the distance to a target also aids the hunter in the placement of the sight of the firearm or bow. For example, if the target is a great distance from a firearm, a hunter can raise the sight of the firearm over the target a select distance to compensate for the trajectory of a projectile (bullet) fired from the firearm. The distance found by the range finder can aid the hunter in determining how much the sight should be raised over the target.
[0004] Traditional range finders can be disruptive in a hunting situation. The hunter must operate the hunting weapon and the range finder at the same time. Moreover, telescopes incorporating range finder circuits are generally heavy, bulky and expensive to purchase.
[0005] For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an inexpensive range finder that is non-disruptive to operate in a hunting situation.
SUMMARY
[0006] The above-mentioned problems with range finders and other problems are addressed by the present invention and will be understood by reading and studying the following specification.
[0007] In one embodiment, a method of using a range finder is disclosed. The method comprises coupling the range finder to a weapon having an associated scope. Positioning at least part of a display of the range finder in front of a select portion of the associated scope. Activating the range finder. Determining the distance to a target and displaying the distance to the target through optics of the scope.
[0008] In another embodiment another method of operating a range finder is disclosed. The method comprises coupling the range finder to a counterweight bar of a bow. Aiming the range finder at a desired target. Activating the range finder. Determining the distance to the target and displaying the distance to the target on a display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention can be more easily understood and further advantages and uses thereof more readily apparent, when considered in view of the description of the preferred embodiments and the following figures in which:
[0010] FIG. 1 is a side perspective view of one embodiment of the present invention coupled to a barrel of a firearm;
[0011] FIG. 2 is a rear view of one embodiment of the present invention;
[0012] FIG. 3 is a top view of one embodiment of the present invention coupled to a barrel of a firearm;
[0013] FIG. 4 is a side partial cut-out view of one embodiment of the present invention;
[0014] FIG. 5 is a flow chart illustrating the operation of one embodiment of the present invention;
[0015] FIG. 6 is a side perspective view of one embodiment of the present invention coupled to a counterweight bar of a bow;
[0016] FIG. 7 is a side perspective view of another embodiment of the present invention coupled to a scope of a firearm;
[0017] FIG. 8 is a top view of yet another embodiment of the present invention coupled to a scope of a firearm; and
[0018] FIG. 9 is a rear view of yet another embodiment of the present invention coupled to a scope.
[0019] In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present invention. Reference characters denote like elements throughout Figures and text.
DETAILED DESCRIPTION
[0020] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the claims and equivalents thereof.
[0021] Embodiments of the present invention relate to range finder that is adapted to be mounted to a firearm. Referring to FIG. 1 , a side perspective view of one embodiment of a range finder 100 coupled to a firearm 101 of the present invention is illustrated. As illustrated, the range finder 100 is coupled to the barrel 112 of the firearm 101 with a first bracket 116 and a second bracket 118 . The range finder 100 of this embodiment is illustrated as having a cylindrical main housing 103 and a display housing 102 that extends from a mid portion 105 of the main housing 103 . Main housing 103 includes a circuit housing 104 and a weather cover 106 . Also illustrated in FIG. 1 , is remote unit 108 . Remote unit 108 is selectively coupled to the forearm 114 of the firearm by an adhesive, a loop and hook fastener or the like. The remote control unit 108 has an activation button 109 . When the activation button 109 is depressed, the range finder 100 is activated. The remote control unit 108 , of the embodiment of FIG. 1 , is electrically coupled to the range finder by attaching cord 110 . In another embodiment, the remote control unit 108 is in wireless communication with the range finder 100 .
[0022] A rear view of one embodiment of a range finder 200 of the present invention is illustrated in FIG. 2 . As illustrated, a display 202 is encased in the display housing 102 . The display may be a liquid crystal display or other type of display capable of conveying a message. When activated, the display 202 displays indicia 204 to convey the distance from the range finder 200 to an object it is pointed at. In the embodiment of FIG. 2 , the indicia 204 conveys the distance in yards and meters. A brightness control 206 is mounted through the display housing 102 to control the brightness of the display 202 .
[0023] Also illustrated in FIG. 2 , is first bracket 116 . As illustrated, the first bracket 116 includes a first bracket portion 208 and a second bracket portion 210 . In this embodiment, the first bracket portion 208 fits over a barrel of a firearm and the second bracket portion 210 fits under the barrel of a firearm. The first bracket portion 208 and the second bracket portion 210 are coupled together by bolts 216 and 218 . In particular, bolt 216 secures the first bracket portion 208 to the second bracket portion 210 with nut 217 and bolt 218 secures the first bracket portion 208 to the second bracket portion 210 with nut 219 . In addition, bolt 216 passes through a connection flange 207 to secure the range finder 200 to the first bracket 116 . As illustrated in FIG. 2 , the display housing 102 extends from a first side 203 of the circuit housing 310 and the flange 207 extends from a second side 205 that is opposite the first side 203 . Moreover, although not shown, the second bracket is constructed in the same manner to couple the range finder 200 to the barrel 112 of the firearm 101 at another location.
[0024] Further illustrated in FIG. 2 , is a first protective material 212 positioned adjacent a first inner surface 209 of the first bracket portion 208 and a second protective material 214 positioned adjacent a second inner surface 211 of the second bracket portion 210 . The first and second protective material 212 and 214 are used to protect the barrel 112 of the firearm 101 . Moreover, in one embodiment, the first and second protective material 212 and 214 come in different thickness to accommodate different barrel diameters. The first and second protective material 212 and 214 are made from material such as foam rubber and the like.
[0025] Referring to FIG. 3 , at top view of an embodiment of a range finder 300 of the present invention is illustrated. As illustrated, the range finder 300 is coupled so that it is positioned along a side 301 of the barrel 112 of the firearm 101 . The positioning of the range finder 300 in this manner not only allows for a quick viewing of the distance by the hunter, it is also positioned so as to not interfere with the sight of the firearm. Embodiments, of the present invention can be mounted on either side of the barrel 112 of the firearm 101 . Also illustrated in FIG. 3 , is an on/off button 306 to turn on and off the range finder 300 .
[0026] FIG. 3 , further illustrates the barrel longitudinal axis 302 of the firearm. The barrel longitudinal axis 302 is the path of a bullet fired from the barrel 302 . Further illustrated is a range finder longitudinal axis 304 . The range finder longitudinal axis 304 is the path upon which the distance is determined. In the embodiments of the present invention, the range finder longitudinal axis 304 is adjusted to be generally parallel to the barrel longitudinal axis 302 so the distance of the bullet path is accurately determined by the range finder 300 . Since some barrels 112 of firearms taper in diameter, a means of compensating to obtain parallel range finder and barrel longitudinal axis' 304 and 305 in needed.
[0027] Referring back to FIG. 2 , one method of adjusting the position of the range finder 200 in relation to the barrel 112 to obtain parallel range finder and barrel longitudinal axis' is illustrated. The connection flange 207 has an adjusting aperture 220 with a lateral length 230 larger than the diameter of bolt 216 to allow the first bracket to be spaced at different distances from the range finder 200 . In particular, bolt 216 passes through adjusting aperture 220 in coupling the first bracket to the range finder 200 . Once a desired distance between the barrel of the firearm and the range finder 200 is achieved, nut 217 is tightened on bolt 216 thereby snugly coupling the first bracket 116 to the flange 207 . Although not shown, the second bracket 118 is constructed in a similar manner to aid in aligning the range finder longitudinal axis 304 with the barrel longitudinal axis 302 of FIG. 3 . In further another embodiment made for a specific barrel, the adjusting aperture 220 is placed in the flange 207 at a select position to obtain a desired distance between the first bracket 116 and the range finder 200 .
[0028] A side partial cross-sectional view of another range finder 400 embodiment of the present invention is illustrated in FIG. 4 . The circuit housing 104 of the range finder 400 encases or houses the range finder circuit 401 that includes a range finder control circuit 402 , a transmitter 404 and a receiver 406 . The range finder control circuit 402 controls the range finding operations and is in electrical communication with the display 202 , the transmitter 404 and the receiver 406 . The transmitter 404 is used to transmit a laser signal and the receiver 406 is used to receive the signal after it has been reflected off a target (the object in which the distance to is to be determined). The range finder control circuit 402 then uses the transit time to determine the distance to the target. Once the distance has been determined, the range finder control 334 , directs the display 202 to display the distance to the target. In the above-described embodiment, a range finder incorporating a light propagation time measuring method to determine the distance to an object is described. However, it will be understood in the art that other types of range finders could be used in the present invention such as the light-section method, the binocular sterosis method and the like, and the present invention is not limited to the light propagation time measuring method.
[0029] Also illustrated in FIG. 4 , are power sources 408 and 410 , which in this embodiment are batteries 408 and 410 . The batteries 408 and 410 are housed in the weather cover 106 and are selectively coupled to supply power to the range finder control circuit 402 , the transmitter 404 , the receiver 406 and the display 202 when the weather cover is coupled to the circuit housing. A battery connection 418 is also shown. The weather cover 106 has a first end 407 and a second end 409 . The second end 409 is enclosed. Moreover, the first end 407 of the weather cover 106 has external threads 412 that terminate in a shoulder 417 . In addition, the circuit housing 104 has a first end 411 that has internal treads 414 that are adapted to threadably engage the external threads 412 of the weather cover 102 . A seal 46 is positioned against the shoulder 417 so that when the external threads 412 of the weather cover 12 are threadably engaged with the internal threads 414 of the circuit housing 104 and tightened, the seal 417 is depressed against the shoulder 417 thereby creating a weatherproof seal. In addition, when the weather cover 106 is coupled to the circuit housing 104 , the batteries 408 and 409 as well as other internal circuits are protected from weather like rain and snow. Moreover, when the weather cover 106 is not coupled to the circuit housing 104 , a user has access to the batteries.
[0030] A flow chart 500 illustrating one embodiment of the operation of the range finder control circuit 402 is illustrated in FIG. 5 . Once, turned on, the range finder control circuit monitors the activation button 108 ( 502 ). Once, the activation button 108 is depressed, a range finder circuit 401 is activated to determine the distance to an object ( 504 ). The distance to the object is then displayed on display 202 ( 506 ). It is determined if 30 seconds has past since the distance was first displayed ( 508 ). If 30 seconds has not past, the activation button is monitored to see if it has been depressed ( 510 ). If it has not been depressed, the display continues to display the distance ( 506 ). If the activation button has been depressed, the range finder circuit is once again activated ( 504 ). If 30 seconds has past since the distance was first displayed, the display is cleared ( 512 ). The range finder control circuit 402 then monitors the activation button to see if it has been depressed ( 502 ). Although, this embodiment uses 30 seconds before clearing the display, other embodiments of the present invention use different selected times.
[0031] Another embodiment of a range finder 600 of present invention is illustrated in FIG. 6 . In this embodiment, the range finder 600 is adapted to be mounted to a counterweight 602 of a bow 620 . Since, the counterweight bar 602 is cylindrical in shape, like the barrel of the firearm, the method of attachment as illustrated in FIG. 2 is also applicable in this embodiment. The embodiment of FIG. 6 , allows a bow hunter to use a range finder 600 in a fast and efficient manner without interfering with the hunt. The bow is illustrated as having a riser 606 , a flexible bow element 612 , a cable guard 608 , bow string 610 and an internally threaded metal insert 604 that is adapted to receive external threads on the counterweight bar 602 .
[0032] Referring to FIG. 7 , yet another embodiment of the range finder 700 of the present invention is illustrated. As illustrated, this embodiment is adapted to be coupled to a scope 701 of a firearm 101 . The range finder 700 is coupled to the scope with the first and second brackets 116 and 118 in the same manner the first and second brackets 116 and 118 couple the above-described range finder embodiments to the barrel 112 of firearm 101 and the counterweight bar 602 of bow 620 . Also illustrated in FIG. 7 is remote control unit 108 and activation button 109 as is described in the embodiment of FIG. 1 . The embodiment of FIG. 7 , also includes a second activation button 720 , wherein in this embodiment a user can either activate the range finder 700 by depressing activation button 109 or second activation button 720 . Moreover, unlike the previous embodiments, in the embodiment of FIG. 7 , the display housing 102 extends from a first end 802 of the circuit housing 104 . This is further illustrated in the range finder 800 embodiment of FIG. 8 . In this embodiment, the display housing 104 extends approximate a first end 804 of the scope 701 . In fact, in this embodiment, the display housing 104 covers a portion of the first end 804 of the scope. FIG. 8 also illustrates the on/off button that is coupled to turn on and off the range finder 800 when depressed. Moreover, FIG. 8 further illustrates a second end 306 of the scope 701 . The second end 806 of the scope 701 is the end in which a user looks through in sighting the scope on a target.
[0033] A rear view of one embodiment of a range finder 900 coupled to a scope 701 is illustrated in FIG. 9 . As illustrated, the display 202 of this embodiment, uses indicia 204 to convey the distance the range finder 900 determines in two different locations. A first location of the display 202 with the indicia 204 is above the scope 701 , so the user can determine distances without looking through the scope 701 . A second location of the display 202 with the indicia 204 is in front of a portion of the scope so it can be viewed by looking through the second end of the scope 806 . In this embodiment, the indicia 204 , in the second display location, is optically adapted so the user can read the conveyed distance through the scope. Moreover, in this embodiment, the second location of the display 202 is positioned in front of an upper portion of the first end 804 of the scope 701 so the distance can be read above a sight 902 of the scope 701 . Placing a portion of the display 202 in front of a portion of the first end 804 of the scope 701 , allows the user the opportunity to view the distance and the sight 902 of the scope 701 at the same time thereby allowing the user the opportunity to read the distance without looking away from the sight 902 .
[0034] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
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A range finder for hunting applications. In one embodiment, a method of using a range finder is disclosed. The method comprises coupling the range finder to a weapon having an associated scope. Positioning at least part of a display of the range finder in front of a select portion of the associated scope. Activating the range finder. Determining the distance to a target and displaying the distance to the target through optics of the scope.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/250,410, filed Oct. 13, 2008 and entitled “Wireless Architecture and Support for Process Control Systems,” which is a continuation-in-part of U.S. patent application Ser. No. 11/156,215, filed Jun. 17, 2005 and entitled “Wireless Architecture and Support for Process Control Systems,” now U.S. Pat. No. 7,436,797. This application is also related to U.S. application Ser. No. 10/464,087, filed Jun. 18, 2003 and entitled “Self-Configuring Communication Networks for use with Process Control Systems,” now U.S. Pat. No. 7,460,865.
[0002] The disclosures of each of U.S. patent application Ser. No. 12/250,410, U.S. Pat. No. 7,436,797, and U.S. Pat. No. 7,460,865 are hereby incorporated by reference herein in their entireties.
FIELD OF TECHNOLOGY
[0003] Methods and apparatuses are disclosed for providing wireless communications within a distributed process control system which establish and maintain consistent wireless communication connections between different remote devices and a base computer in a process control system.
BACKGROUND
[0004] Process control systems are widely used in factories and/or plants in which products are manufactured or processes are controlled (e.g., chemical manufacturing, power plant control, etc.). Process control systems are also used in the harvesting of natural resources such as, for example, oil and gas drilling and handling processes, etc. In fact, virtually any manufacturing process, resource harvesting process, etc. can be automated through the application of one or more process control systems. It is believed the process control systems will eventually be used more extensively in agriculture as well.
[0005] The manner in which process control systems are implemented has evolved over the years. Older generations of process control systems were typically implemented using dedicated, centralized hardware and hard-wired connections.
[0006] However, modern process control systems are typically implemented using a highly distributed network of workstations, intelligent controllers, smart field devices, and the like, some or all of which may perform a portion of an overall process control strategy or scheme. In particular, most modern process control systems include smart field devices and other process control components that are communicatively coupled to each other and/or to one or more process controllers via one or more digital data buses. In addition to smart field devices, modern process control systems may also include analog field devices such as, for example, 4-20 milliamp (mA) devices, 0-10 volts direct current (VDC) devices, etc., which are typically directly coupled to controllers as opposed to a shared digital data bus or the like.
[0007] In a typical industrial or process plant, a distributed control system (DCS) is used to control many of the industrial processes performed at the plant. The plant may have a centralized control room having a computer system with user input/output (I/O), a disc I/O, and other peripherals known in the computing art with one or more process controllers and process I/O subsystems communicatively connected to the centralized control room. Additionally, one or more field devices are typically connected to the I/O subsystems and to the process controllers to implement control and measurement activities within the plant. While the process I/O subsystem may include a plurality of I/O ports connected to the various field devices throughout the plant, the field devices may include various types of analytical equipment, silicon pressure sensors, capacitive pressure sensors, resistive temperature detectors, thermocouples, strain gauges, limit switches, on/off switches, flow transmitters, pressure transmitters, capacitance level switches, weigh scales, transducers, valve positioners, valve controllers, actuators, solenoids, indicator lights or any other device typically used in process plants.
[0008] As used herein, the term “field device” encompasses these devices, as well as any other device that performs a function in a control system. In any event, field devices may include, for example, input devices (e.g., devices such as sensors that provide status signals that are indicative of process control parameters such as, for example, temperature, pressure, flow rate, etc.), as well as control operators or actuators that perform actions in response to commands received from controllers and/or other field devices.
[0009] Traditionally, analog field devices have been connected to the controller by two-wire twisted pair current loops, with each device connected to the controller by a single two-wire twisted pair. Analog field devices are capable of responding to or transmitting an electrical signal within a specified range. In a typical configuration, it is common to have a voltage differential of approximately 20-25 volts between the two wires of the pair and a current of 4-20 mA running through the loop. An analog field device that transmits a signal to the control room modulates the current running through the current loop, with the current being proportional to the sensed process variable.
[0010] An analog field device that performs an action under control of the control room is controlled by the magnitude of the current through the loop, which current is modulated by the I/O port of the process I/O system, which in turn is controlled by the controller. Traditional two-wire analog devices having active electronics can also receive up to 40 milliwatts of power from the loop. Analog field devices requiring more power are typically connected to the controller using four wires, with two of the wires delivering power to the device. Such devices are known in the art as four-wire devices and are not power limited, as typically are two-wire devices.
[0011] A discrete field device can transmit or respond to a binary signal. Typically, discrete field devices operate with a 24 volt signal (either AC or DC), a 110 or 240 volt AC signal, or a 5 volt DC signal. Of course, a discrete device may be designed to operate in accordance with any electrical specification required by a particular control environment. A discrete input field device is simply a switch which either makes or breaks the connection to the controller, while a discrete output field device will take an action based on the presence or absence of a signal from the controller.
[0012] Historically, most traditional field devices have had either a single input or a single output that was directly related to the primary function performed by the field device. For example, the only function implemented by a traditional analog resistive temperature sensor is to transmit a temperature by modulating the current flowing through the two-wire twisted pair, while the only function implemented by a traditional analog valve positioner is to position a valve somewhere between a fully open and a fully closed position based on the magnitude of the current flowing through the two-wire twisted pair.
[0013] More recently, field devices that are part of hybrid systems become available that superimpose digital data on the current loop used to transmit analog signals. One such hybrid system is known in the control art as the Highway Addressable Remote Transducer (HART) protocol. The HART system uses the magnitude of the current in the current loop to send an analog control signal or to receive a sensed process variable (as in the traditional system), but also superimposes a digital carrier signal upon the current loop signal. The HART protocol makes use of the Bell 202 Frequency Shift Keying (FSK) standard to superimpose the digital signals at a low level on top of the 4-20 mA analog signals. This enables two-way field communication to take place and makes it possible for additional information beyond just the normal process variable to be communicated to/from a smart field instrument. The HART protocol communicates at 1200 bps without interrupting the 4-20 mA signal and allows a host application (master) to get two or more digital updates per second from a field device. As the digital FSK signal is phase continuous, there is no interference with the 4-20 mA signal.
[0014] The FSK signal is relatively slow and can therefore provide updates of a secondary process variable or other parameter at a rate of approximately 2-3 updates per second. Generally, the digital carrier signal is used to send secondary and diagnostic information and is not used to realize the primary control function of the field device. Examples of information provided over the digital carrier signal include secondary process variables, diagnostic information (including sensor diagnostics, device diagnostics, wiring diagnostics, and process diagnostics), operating temperatures, a sensor temperature, calibration information, device ID numbers, materials of construction, configuration or programming information, etc. Accordingly, a single hybrid field device may have a variety of input and output variables and may implement a variety of functions.
[0015] More recently, a newer control protocol has been defined by the Instrument Society of America (ISA). The new protocol is generally referred to as Fieldbus, and is specifically referred to as SP50, which is as acronym for Standards and Practice Subcommittee 50. The Fieldbus protocol defines two subprotocols. An H1 Fieldbus network transmits data at a rate up to 31.25 kilobits per second and provides power to field devices coupled to the network. An H2 Fieldbus network transmits data at a rate up to 2.5 megabits per second, does not provide power to field devices connected to the network, and is provided with redundant transmission media. Fieldbus is a nonproprietary open standard and is now prevalent in the industry and, as such, many types of Fieldbus devices have been developed and are in use in process plants. Because Fieldbus devices are used in addition to other types of field devices, such as HART and 4-20 mA devices, a separate support and I/O communication structure is associated with each of these different types of devices.
[0016] Newer smart field devices, which are typically all digital in nature, have maintenance modes and enhanced functions that are not accessible from or compatible with older control systems. Even when all components of a distributed control system adhere to the same standard (such as the Fieldbus standard), one manufacturer's control equipment may not be able to access the secondary functions or secondary information provided by another manufacturer's field devices.
[0017] Thus, one particularly important aspect of process control system design involves the manner in which field devices are communicatively coupled to each other, to controllers and to other systems or devices within a process control system or a process plant. In general, the various communication channels, links and paths that enable the field devices to function within the process control system are commonly collectively referred to as an input/output (I/O) communication network.
[0018] The communication network topology and physical connections or paths used to implement an I/O communication network can have a substantial impact on the robustness or integrity of field device communications, particularly when the I/O communications network is subjected to environmental factors or conditions associated with the process control system. For example, many industrial control applications subject field devices and their associated I/O communication networks to harsh physical environments (e.g., high, low or highly variable ambient temperatures, vibrations, corrosive gases or liquids, etc.), difficult electrical environments (e.g., high noise environments, poor power quality, transient voltages, etc.), etc. In any case, environmental factors can compromise the integrity of communications between one or more field devices, controllers, etc. In some cases, such compromised communications could prevent the process control system from carrying out its control routines in an effective or proper manner, which could result in reduced process control system efficiency and/or profitability, excessive wear or damage to equipment, dangerous conditions that could damage or destroy equipment, building structures, the environment and/or people, etc.
[0019] In order to minimize the effect of environmental factors and to assure a consistent communication path, I/O communication networks used in process control systems have historically been hardwired networks, with the wires being encased in environmentally protected materials such as insulation, shielding and conduit. Also, the field devices within these process control systems have typically been communicatively coupled to controllers, workstations, and other process control system components using a hardwired hierarchical topology in which non-smart field devices are directly coupled to controllers using analog interfaces such as, for example, 4-20 mA, 0-10 VDC, etc. hardwired interfaces or I/O boards. Smart field devices, such as Fieldbus devices, are also coupled via hardwired digital data busses, which are coupled to controllers via smart field device interfaces.
[0020] While hardwired I/O communication networks can initially provide a robust I/O communication network, their robustness can be seriously degraded over time as a result of environmental stresses (e.g., corrosive gases or liquids, vibration, humidity, etc.). For example, contact resistances associated with the I/O communication network wiring may increase substantially due to corrosion, oxidation and the like. In addition, wiring insulation and/or shielding may degrade or fail, thereby creating a condition under which environmental electrical interference or noise can more easily corrupt the signals transmitted via the I/O communication network wires. In some cases, failed insulation may result in a short circuit condition that results in a complete failure of the associated I/O communication wires.
[0021] Additionally, hardwired I/O communication networks are typically expensive to install, particularly in cases where the I/O communication network is associated with a large industrial plant or facility that is distributed over a relatively large geographic area, for example, an oil refinery or chemical plant that consumes several acres of land. In many instances, the wiring associated with the I/O communication network must span long distances and/or go through, under or around many structures (e.g., walls, buildings, equipment, etc.) Such long wiring runs typically involve substantial amounts of labor, material and expense. Further, such long wiring runs are especially susceptible to signal degradation due to wiring impedances and coupled electrical interference, both of which can result in unreliable communications.
[0022] Moreover, such hardwired I/O communication networks are generally difficult to reconfigure when modifications or updates are needed. Adding a new field device typically requires the installation of wires between the new field device and a controller. Retrofitting a process plant in this manner may be very difficult and expensive due to the long wiring runs and space constraints that are often found in older process control plants and/or systems. High wire counts within conduits, equipment and/or structures interposing along available wiring paths, etc., may significantly increase the difficulty associated with retrofitting or adding field devices to an existing system. Exchanging an existing field device with a new device having different field wiring requirements may present the same difficulties in the case where more and/or different wires have to be installed to accommodate the new device. Such modifications may often result in significant plant downtime.
[0023] It has been suggested to use wireless I/O communication networks to alleviate some of the difficulties associated with hardwired I/O networks. For example, Tapperson et al., U.S. patent application Ser. No. 09/805,124 discloses a system which provides wireless communications between controllers and field devices to augment or supplement the use of hardwired communications. However, most, if not all, wireless I/O communication networks actually implemented within process plants today are implemented using relatively expensive hardware devices (e.g., wireless enabled routers, hubs, switches, etc.), most of which consume a relatively large amount of power. Further, intermittent interferences, such as the passing of trucks, trains, environmental or weather related conditions, etc., make wireless communication networks unreliable and therefore problematic.
[0024] In addition, known wireless I/O communication networks, including the hardware and software associated therewith, generally use point-to-point communication paths that are carefully selected during installation and fixed during subsequent operation of the system. Establishing fixed communication paths within these wireless I/O communication networks typically involves the use of one or more experts to perform an expensive site survey that enables the experts to determine the types and/or locations of the transceivers and other communication equipment. Further, once the fixed point-to-point communication paths have been selected via the site survey results, one or more of the experts must then configure equipment, tune antennas, etc. While the point-to-point paths are generally selected to insure adequate wireless communications, changes within the plant, such as the removal or addition of equipment, walls, or other structures may make the initially selected paths less reliable, leading to unreliable wireless communications.
[0025] While wireless I/O communication networks can, for example, alleviate the long term robustness issues associated with hardwired communication paths, these wireless I/O communication networks are relatively inflexible and are considered by most in the process control industry to be too unreliable to perform important or necessary process control functions. For example, there is currently no easy manner of telling when a wireless communication is no longer functioning properly, or has degraded to the point that communications over the wireless link are likely to be unreliable or to cease altogether. As a result, current process control operators have very little faith in wireless communication networks when implemented for important and necessary process control functions.
[0026] Thus, due to the costs associated with installing a wireless I/O communication network (e.g., site surveys, expert configuration, etc.), and the relative little amount of faith that current process control system operators have in wireless communications, wireless I/O communication networks are often cost prohibitive for what they provide, particularly for relatively large process control systems such as those typically used in industrial applications.
SUMMARY OF THE DISCLOSURE
[0027] A wireless communication architecture for use in a process control system is disclosed which includes the use of mesh and possibly a combination of mesh and point-to-point communications to produce a more robust wireless communication network that can be easily set up, configured, changed and monitored, to thereby make the wireless communication network more robust, less expensive and more reliable. The wireless communication architecture is implemented in a manner that is independent of the specific messages or virtual communication paths within the process plant and, in fact, the wireless communication network is implemented to allow virtual communication paths to be established and used within the process control system in a manner that is independent of the manner in which the wireless signals are sent between different wireless transmitting and receiving devices within the process plant.
[0028] In a refinement, one or more environmental nodes are used to control and optimize the operation of the wireless communication network. The environmental node(s) are linked to field “environmental” devices providing signals indicative of one or more environmental factors such as temperature, barometric pressure, humidity, rainfall and radio frequency (RF) ambient noise, amongst other environmental factors that could alter the operation of the network.
[0029] In another refinement, the network includes a main controller linked to a wireless card. The wireless card is in communication with a repeater node which, in turn, is in communication with a field node. The field node is linked to a plurality of field devices. In another refinement, the repeater node is eliminated. In another refinement, an environmental node and environmental detection devices as discussed above are incorporated with or without one or more repeater nodes. In a further refinement, the field and environmental nodes include a plurality of ports for communication with the field devices.
[0030] In a refinement, the wireless communication network is set up to transmit HART communication signals between different devices within the process plant to thereby enable a robust wireless communication network to be used in a process plant or any other environment having HART capable devices.
[0031] In an embodiment, a process control wireless communication network is disclosed which comprises a base node, a field node, an environmental node and a host. The base node is communicatively coupled to the host. The base, field and environmental nodes each comprise a wireless conversion unit and a wireless transceiver. The wireless transceivers of the base, the field and environmental nodes effect wireless communication among the base, field and environmental nodes. The field node comprises at least one field device providing process controlled data. The environmental node comprises at least one field device providing data regarding environmental factors that may affect operation of the wireless communication network.
[0032] In a refinement, the network also comprises a repeater node comprising a wireless conversion unit in a wireless transceiver. The repeater node effects wireless communications amongst the base, field and environmental node.
[0033] In another refinement, the environmental node comprises a plurality of field devices, each providing data selected from the group consisting of temperature, barometric pressure, humidity, rainfall and radio frequency ambient noise.
[0034] In another refinement, at least some of the field devices are HART protocol devices. In another refinement, at least some of the field devices are FIELDBUS™ protocol devices.
[0035] In another refinement, the network comprises a plurality of environmental nodes strategically placed about a process area for communicating environmental data for different locations within the process area.
[0036] In a refinement, the base, environmental and field nodes form a mesh communications network, providing multiple communication pathway options between any two wireless nodes. In another refinement, the base, environmental and field nodes form a point-to-point communications network. In yet another refinement, the network comprises a switch device to convert the base, environmental and field nodes from a mesh communications network to a point-to-point communications network and vice versa.
[0037] Communication tools are also disclosed to enable an operator to view a graphic of the wireless communication system to easily determine the actual wireless communication paths established within a process plant, to determine the strength of any particular path and to determine or view the ability of signals to propagate through the wireless communication network from a sender to a receiver to thereby enable a user or operator to assess the overall operational capabilities of the wireless communication network.
[0038] In a refinement, the communication tools include one or more of graphical topology maps illustrating connectivity between nodes, tabular presentations showing the connectivity matrix and hop counts and actual maps showing location and connectivity of the hardware devices. The monitor that illustrates wireless communications between the base, field and environmental nodes of the network may be associated with the base node or the host. In another refinement, the topology screen display also illustrates structural features of the process area or environment in which the base, field and environmental nodes are disposed. In another refinement, the host is programmed to provide a tabular screen display listing hop counts for communications between the various nodes of the network.
[0039] In another refinement, the wireless communication network is configured to transmit Fieldbus communication signals between different devices within the process plant to thereby enable a robust wireless communication network to be used in a process plant or environment having Fieldbus capable devices in combination with or instead of HART capable devices.
[0040] In a refinement, a method for controlling a process is disclosed which comprises receiving field data from at least one field device, transmitting the field data wirelessly from a field node to a base node, converting the field data to a different protocol, transmitting the field data of the different protocol to a routing node, determining at the routing node an object device for receiving the field data of the different protocol, and sending the field data of the different protocol to the object device.
[0041] In another refinement, a method for monitoring a wireless process control network is disclosed which comprises receiving environmental data from one or more environmental field devices of an environmental node, wirelessly transmitting the environmental data to a base node, transmitting the environmental data to a host, interpreting the environmental data at the host, sending a command from the host to the base node to adjust at least one operating parameter of the wireless network based upon the environmental data, and transmitting the command from the base node to at least one field node comprising at least one field device for executing the command.
[0042] Other advantages and features will become apparent upon reading the following detailed description and independent claims, an upon reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] For more complete understanding of this disclosure, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples. In the drawings:
[0044] FIG. 1 is a combined block and schematic diagram of a conventional hardwired distributed control system;
[0045] FIG. 2 is a combined block and schematic diagram of a wireless communication network within a portion of a process environment designed in accordance with this disclosure;
[0046] FIG. 3 is a diagram of a wireless communication network within a process environment illustrating both mesh and point-to-point wireless communications;
[0047] FIG. 4 is a block diagram of a mesh and point-to-point enabled communication device that may be used to switch between mesh and point-to-point communications within the communication network of FIG. 3 .
[0048] FIG. 5 is an example of a geometric topology screen display created by a wireless network analysis tool illustrating the wireless communications between different devices within the wireless communication system designed in accordance with this disclosure;
[0049] FIG. 6 is an example screen display presented in tabular form and created by a wireless network analysis tool illustrating the number of hops or the hop count between each of the wireless communication devices within a disclosed wireless communication system;
[0050] FIG. 7 is an example of a topology screen display created by a disclosed wireless network analysis tool illustrating the wireless communications within a graphic of a plant layout to enable an operator or other user to view the specific communications occurring within the wireless communication network and potential physical obstacles presented by the plant layout;
[0051] FIG. 8 is an example screen display created by a disclosed wireless network analysis tool allowing a user or operator to specify the channel routing and identification within the wireless communication network;
[0052] FIG. 9 is an example screen display created by a wireless network analysis tool illustrating graphical displays of information about the wireless communications between different devices within the wireless communication system to enable a user or operator to analyze the operational capabilities and parameters of the wireless communication network; and
[0053] FIG. 10 is a block diagram of a wireless communication device that implements a HART communication protocol wirelessly using a second communication protocol, e.g. the EMBER® protocol.
[0054] It should be understood that the drawings are not to scale and that the embodiments are illustrated by graphic symbol, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details have been omitted which are not necessary for an understanding of the disclosed embodiments and methods or which render other details difficult to perceive. This disclosure is not limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0055] FIG. 1 illustrates a typical hardwired distributed process control system 10 which includes one or more process controllers 12 connected to one or more host workstations or computers 14 (which may be any type of personal computer or workstation). The process controllers 12 are also connected to banks of input/output (I/O) devices 20 , 22 each of which, in turn, is connected to one or more field devices 25 - 39 . The controllers 12 , which may be, by way of example only, DeltaV™ controllers sold by Fisher-Rosemount Systems, Inc., are communicatively connected to the host computers 14 via, for example, an Ethernet connection 40 or other communication link. Likewise, the controllers 12 are communicatively connected to the field devices 25 - 39 using any desired hardware and software associated with, for example, standard 4-20 mA devices and/or any smart communication protocol such as the Fieldbus or HART protocols. As is generally known, the controllers 12 implement or oversee process control routines stored therein or otherwise associated therewith and communicate with the devices 25 - 39 to control a process in any desired manner.
[0056] The field devices 25 - 39 may be any types of devices, such as sensors, valves, transmitters, positioners, etc. while the I/O cards within the banks 20 and 22 may be any types of I/O devices conforming to any desired communication or controller protocol such as HART, Fieldbus, Profibus, etc. In the embodiment illustrated in FIG. 1 , the field devices 25 - 27 are standard 4-20 mA devices that communicate over analog lines to the I/O card 22 A. The field devices 28 - 31 are illustrated as HART devices connected to a HART compatible I/O device 20 A. Similarly, the field devices 32 - 39 are smart devices, such as Fieldbus field devices, that communicate over a digital bus 42 or 44 to the I/O cards 20 B or 22 B using, for example, Fieldbus protocol communications. Of course, the field devices 25 - 39 and the banks of I/O cards 20 and 22 could conform to any other desired standard(s) or protocols besides the 4-20 mA, HART or Fieldbus protocols, including any standards or protocols developed in the future.
[0057] Each of the controllers 12 is configured to implement a control strategy using what are commonly referred to as function blocks, wherein each function block is a part (e.g., a subroutine) of an overall control routine and operates in conjunction with other function blocks (via communications called links) to implement process control loops within the process control system 10 . Function blocks typically perform one of an input function, such as that associated with a transmitter, a sensor or other process parameter measurement device, a control function, such as that associated with a control routine that performs PID, fuzzy logic, etc. control, or an output function that controls the operation of some device, such as a valve, to perform some physical function within the process control system 10 . Of course hybrid and other types of function blocks exist. Groups of these function blocks are called modules. Function blocks and modules may be stored in and executed by the controller 12 , which is typically the case when these function blocks are used for, or are associated with standard 4-20 mA devices and some types of smart field devices, or may be stored in and implemented by the field devices themselves, which may be the case with Fieldbus devices. While the control system 10 illustrated in FIG. 1 is described as using function block control strategy, the control strategy could also be implemented or designed using other conventions, such as ladder logic, sequential flow charts, etc. and using any desired proprietary or non-proprietary programming language.
[0058] As evident from the discussion of FIG. 1 , the communications between the host workstations 14 and the controllers 12 and between the controllers 12 and the field devices 25 - 39 are implemented with hardwired communication connections, including one or more of HART, Fieldbus and 4-20 mA hardwired communication connections. However, as noted above, it is desirable to replace or augment the hardwired communication connections within the process environment of FIG. 1 with wireless communications in a manner that is reliable, that is easy to set up and configure, that provides an operator or other user with the ability to analyze or view the functioning capabilities of the wireless network, etc.
[0059] FIG. 2 illustrates a wireless communication network 60 that may be used to provide communications between the different devices illustrated in FIG. 1 and, in particular, between the controllers 12 (or the associated I/O devices 22 ) of FIG. 1 and the field devices 25 - 39 , between the controllers 12 and the host workstations 14 or between the host workstations 14 and the field devices 25 - 39 of FIG. 1 . However, it will be understood that the wireless communication network 60 of FIG. 2 could be used to provide communications between any other types or sets of devices within a process plant or a process environment.
[0060] The communication network 60 of FIG. 2 is illustrated as including various communication nodes including one or more base nodes 62 , one or more repeater nodes 64 , one or more environment nodes 66 (illustrated in FIG. 2 as nodes 66 a and 66 b ) and one or more field nodes 68 (illustrated in FIG. 2 as nodes 68 a , 68 b and 68 c ). Generally speaking, the nodes of the wireless communication network 60 operate as a mesh type communication network, wherein each node receives a communication, determines if the communication is ultimately destined for that node and, if not, repeats or passes the communication along to any other nodes within communication range. As is known, any node in a mesh network may communicate with any other node in range to forward communications within the network, and a particular communication signal may go through multiple nodes before arriving at the desired destination.
[0061] As illustrated in FIG. 2 , the base node 62 includes or is communicatively coupled to a work station or a host computer 70 which may be for example any of the hosts or workstations 14 of FIG. 1 . While the base node 62 is illustrated as being linked to the workstation 70 via a hardwired Ethernet connection 72 , any other communication link may be used instead. As will be described in more detail later, the base node 62 includes a wireless conversion or communication unit 74 and a wireless transceiver 76 to effect wireless communications over the network 60 . In particular, the wireless conversion unit 74 takes signals from the workstation or host 70 and encodes these signals into a wireless communication signal which is then sent over the network 60 via the transmitter portion of the transceiver 76 . Conversely, the wireless conversion unit 74 decodes signals received via the receiver portion of the transceiver 76 to determine if that signal is destined for the base node 62 and, if so, further decodes the signal to strip off the wireless encoding to produce the original signal generated by the sender at a different node 64 , 66 or 68 within the network 60 .
[0062] As will be understood, in a similar manner, each of the other communication nodes including the repeater nodes 64 , the environmental nodes 66 and the field nodes 68 includes a communication unit 74 and a wireless transceiver 76 for encoding, sending and decoding signals sent via the wireless mesh network 60 . While the different types of nodes 64 , 66 , 68 within the communication network 60 differ in some important ways, each of these nodes generally operates to receive wireless signals, decode the signal enough to determine if the signal is destined for that node (or a device connected to that node outside of the wireless communication network 60 ), and repeat or retransmit the signal if the signal is not destined for that node and has not previously been transmitted by that node. In this manner, signals are sent from an originating node to all the nodes within wireless communication range, each of the nodes in range which are not the destination node then retransmits the signal to all of the other nodes within range of that node, and the process continues until the signal has propagated to all of the nodes within range of at least one other node.
[0063] However, the repeater node 64 operates to simply repeat signals within the communication network 60 to thereby relay a signal from one node through the repeater node 64 to a second node 62 , 66 or 68 . Basically, the function of the repeater node 64 is to act as a link between two different nodes to assure that a signal is able to propagate between the two different nodes when these nodes are not or may not be within direct wireless communication range of one another. Because the repeater node 64 is not generally tied to other devices at the node, the repeater node 64 only needs to decode a received signal enough to determine if the signal is a signal that has been previously repeated by the repeater node (that is, a signal that was sent by the repeater node at a previous time and which is simply being received back at the repeater node because of the repeating function of a different node in the communication network 60 ). If the repeater node has not received a particular signal before, the repeater node 64 simply operates to repeat this signal by retransmitting that signal via the transceiver 74 of the repeater node 64 .
[0064] On the other hand, each of the field nodes 68 is generally coupled to one or more devices within the process plant environment and, generally speaking, is coupled to one or more field devices, illustrated as field devices 80 - 85 in FIG. 2 . The field devices 80 - 85 may be any type of field devices including, for example, four-wire devices, two-wire devices, HART devices, Fieldbus devices, 4-20 mA devices, smart or non-smart devices, etc. For the sake of illustration, the field devices 80 - 85 of FIG. 2 are illustrated as HART field devices, conforming to the HART communication protocol. Of course, the devices 80 - 85 may be any type of device, such as a sensor/transmitter device, a valve, a switch, etc. Additionally, the devices 80 - 85 may be other than traditional field devices such as controllers, I/O devices, work stations, or any other types of devices.
[0065] In any event, the field node 68 a , 68 b , 68 c includes signal lines attached to their respective field devices 80 - 85 to receive communications from and to send communications to the field devices 80 - 85 . Of course, these signal lines may be connected directly to the devices 80 - 85 , in this example, a HART device, or to the standard HART communication lines already attached to the field devices 80 - 85 . If desired, the field devices 80 - 85 may be connected to other devices, such as I/O devices 20 A or 22 A of FIG. 1 , or to any other desired devices via hardwired communication lines in addition to being connected to the field nodes 68 a , 68 b , 68 c . Additionally, as illustrated in FIG. 2 , any particular field node 68 a , 68 b , 68 c may be connected to a plurality of field devices (as illustrated with respect to the field node 68 c , which is connected to four different field devices 82 - 85 ) and each field node 68 a , 68 b , 68 c operates to relay signals to and from the field devices 80 - 85 to which it is connected.
[0066] In order to assist in the management in the operation of the communication network 60 , the environmental nodes 66 are used. In this case, the environmental nodes 66 a and 66 b include or are communicatively connected to devices or sensors 90 - 92 that measure environmental parameters, such as the humidity, temperature, barometric pressure, rainfall, or any other environmental parameters which may affect the wireless communications occurring within the communication network 60 . As discussed in more detail below, this information may be useful in analyzing and predicting problems within the communication network, as many disruptions in wireless communications are at least partially attributable to environmental conditions. If desired, the environmental sensors 90 - 92 may be any kind of sensor and may include, for example, HART sensors/transmitters, 4-20 mA sensors or on board sensors of any design or configuration. Of course, each environmental node 66 a , 66 b may include one or more environmental sensors 90 - 92 and different environmental nodes may include the same or different types or kinds of environmental sensors if so desired. Likewise, if desired, one or more of the nodes 66 a , 66 b may include an electromagnetic ambient noise measurement device 93 to measure the ambient electromagnetic noise level, especially at the wavelengths used by the communication network 60 to transmit signals. Of course, if a spectrum other than the RF spectrum is used by the communication network 60 , a different type of noise measurement device may be included in one or more of the environmental nodes 66 . Still further, while the environmental nodes 66 of FIG. 2 are described as including environmental measurement devices or sensors 90 - 93 , any of the other nodes 68 could include those measurement devices so that an analysis tool may be able to determine the environmental conditions at each node when analyzing the operation of the communication network 60 .
[0067] Using the communication system 60 of FIG. 2 , an application running on the workstation 70 can send packets of data to and receive packets of wireless data from the wireless base card 74 residing in a standard controller 75 at the base node 62 . This controller 75 may be, for example, a DeltaV controller and the communications may be the same as with a standard I/O card via the Ethernet connection to the DeltaV controller. The I/O card in this case includes a wireless base card 74 , though as far as the controller and PC Application goes, it appears as a standard HART I/O card.
[0068] In this case, the wireless card 74 at the base node 62 encodes the data packet for wireless transmission and the transceiver 76 at the base node 62 transmits the signal. FIG. 2 illustrates that the transmitted signal may go directly to some of the field nodes such as nodes 68 a and 68 b , but may also propagate to other field nodes, such as node 68 c , via the repeater node 64 . In the same manner, signals created at and propagated by the field nodes 68 may go directly to the base node 62 and other field nodes 68 or may be transmitted through other nodes such as the repeater node 64 or another field node before being transmitted to the base node 62 . Thus, the communication path over the wireless network 60 may or may not go through a repeater node 64 and, in any particular case, may go through numerous nodes before arriving at the destination node. If a sending node is in direct communication reach of the base unit 62 , then it will exchange data directly. Whether or not the packets pass through a repeater node 64 is completely transparent to the end user, or even to the card firmware.
[0069] It will be noted that FIG. 2 is a schematic diagram and the placement of the environmental nodes 66 a , 66 b relative to the field nodes 68 a - 68 c are not intended to be relative to their actual placement in an actual process control area. Rather, the environmental nodes 66 a , 66 b (and other environmental nodes not pictured or a single environmental node) are intended to be placed about the process control area in a logical and strategic manner as shown in FIG. 7 . In other words, environmental nodes 66 should be placed at spaced apart location, such as at opposing ends of large obstacles or pieces of equipment or near roadways where interference from moving vehicles may be present. Also, environmental nodes should be placed both indoors and outdoors if applicable. The network of environmental nodes 66 is intended to be used by the base node 62 and host 70 as a means for monitoring the operation of the wireless network 60 and modifying the operation of the network 60 by increasing or decreasing signal strength, gain, frequency etc.
[0070] It will be noted that the field nodes 68 are placed at or near various process stations. The field nodes 68 may be important safety devices or may be used to monitor and/or control various processes. Further, more than one repeater node 64 may be used and, in fact, FIG. 2 is but one example as it may be determined that only a single environmental node 66 is necessary, that more than one or no repeater nodes 64 are needed and that fewer than three or more than three field nodes 68 are necessary.
[0071] Turning to FIGS. 3 and 4 , it is anticipated that the wireless network 60 of FIG. 2 may need to be switched back and forth between mesh and point-to-point communication modes. FIG. 3 illustrates a network 100 with a base node 101 in communication with repeater nodes 102 a , 102 b , 102 c . The repeater nodes 102 a - 102 c are, in turn, in communication with a plurality or a cluster of either environmental nodes, field nodes or combination of the two as shown generally at 104 . A point-to-point wireless communication system for FIG. 3 is shown in solid line while an alternative mesh configuration is shown in phantom line.
[0072] Turning to FIG. 4 , a switch device 105 is shown schematically which may be disposed in the base node 101 in addition to the wireless transceiver 76 . The switch 105 is intended to convert the network 100 from a mesh wireless network as shown by the phantom lines in FIG. 3 to a point-to-point wireless network as shown by way of example in the solid line of FIG. 3 . Of course, the point-to-point communications can be configured in any manner and the solid lines shown in FIG. 3 are but one example. The switch device 105 as shown in FIG. 4 can include an electronic switch element 106 that shifts the device 105 between a mesh wireless transceiver 76 a and a point-to-point wireless transceiver 76 b.
[0073] As noted above, the disclosed network 60 includes a base node 62 and host 70 that may be programmed to provide a variety of graphical interfaces that will be useful to the operator. Examples of such graphical interfaces are shown in FIGS. 5-9 . Turning to FIG. 5 , a geometric topology screen display 110 is disclosed which illustrates a wireless network between a base node BA and a plurality of other nodes which may be one or more repeater nodes, field nodes and environmental nodes numbered in FIG. 5 as 03 , 04 , 05 , 07 , 08 , 09 , 10 ( 0 A), and 11 ( 0 B). The topology display 110 of FIG. 5 illustrates a successful communication between two nodes with a solid line, one example of which is the communication between the base node BA and the node 7 . A successful communication in one direction only is illustrated by a line with cross hatches, one example of which is the line between the nodes 03 and 10 ( 0 A). An unsuccessful communication is indicated by a dashed or phantom line, one example of which is the lack of communication illustrated by the dashed line between nodes 05 and 11 ( 0 B). FIG. 5 also illustrates the “hop count” between nodes. For example, looking at nodes 04 and 07 , the dashed or phantom line between nodes 04 and 07 of FIG. 5 make it clear that there is no direct wireless communication between nodes 04 and 07 while there is communication between nodes 04 and 05 and one-way communication between nodes 05 and 07 . Thus, for one-way communication between nodes 04 and 07 , there is a hop count of 2 (node 04 to node 05 and node 05 to node 07 ). Alternatively, for two-way communication between nodes 04 and 07 , there is also a hop count of 2 (node 07 to node 03 and node 03 to node 04 ). Obviously, the lower the hop count the better and the more reliable the communication.
[0074] The hop counts for the network shown in FIG. 5 are shown in tabular form in FIG. 6 . The nodes labeled 10 and 11 in FIG. 5 are also indicated as 0 A and 0 B in FIG. 6 . The base node BA communicates directly with nodes 03 through 0 B and therefore the hop count between the base node BA and any one of 03 through 0 B is one as indicated in the top row of the table shown in FIG. 6 . Turning to the second row of the table of FIG. 6 , it will be noted that the hop count between node 03 and any of the other nodes is also 1 as node 03 of FIG. 5 includes no dashed lines emanating from it. However, turning to the third row of the table of FIG. 6 and referring to FIG. 5 , it will be noted that node 04 includes a dashed line extended between node 04 and node 07 and therefore direct communication between node 04 and node 07 is not possible. Thus, to connect from node 04 to node 07 , the communication proceeds through node 05 for a hop count of 2. Still further, because there is a cross-hatched line between node 04 and node 09 in FIG. 5 , direct two-way communication between node 04 and 09 is not possible. Accordingly, for two-way communication between nodes 04 and 09 , the communication must pass through node 08 as indicated in the table of FIG. 6 . All of the entries that are circled in FIG. 6 indicate a hop count of 2.
[0075] Turning to FIG. 7 , a topology map similar to that shown in FIG. 5 is illustrated as an overlay of a map for an actual process environment. Specifically, each point is the location of 1 of the 9 nodes show in FIG. 5 and listed in the table of FIG. 6 . FIG. 7 provides the operator with an opportunity to view the wireless connectivities within the context of the actual operating environment. Global positioning system reference points are indicated at 111 , 112 so actual distances between the nodes can be determined.
[0076] Turning to FIG. 8 , the field devices 80 - 85 and 90 - 93 may appear to the base node 62 or host 70 as a standard HART device. This enables standard applications such as AMS software to run seamlessly on top of the wireless network 60 . To utilize the AMS software, the wireless field nodes 66 and 68 need to know how to route messages. This is accomplished by utilizing a routing map 120 as illustrated in FIG. 8 . This map 120 is stored in the nonvolatile memory of the base unit 62 , but also could be stored in the memory of the host 70 . The actual routing takes advantage of incorporating a base card that is identical to an 8 channel HART card. The routing tool then maps 8 virtual HART channels to remote field nodes and their channels. FIG. 8 illustrates a mapping configuration for 8 different devices. Each Field type wireless node may include 4 different HART channels, though the field device will have one unique ID. The actual target channel is embedded in the wireless packet. Each ID for each wireless unit is based on 2 bytes. The first byte is the network number and correlates to an actual radio channel in the wireless interface. The number of the first byte can range from 1 to 12. The second byte is the identification of the node in the network and can range from 1 to 15. When a node is initialized for a first time, its default address is 010F, which means network 1 , address 15 . The exception to this address scheme is the base unit which always has BA as its first byte, the second byte representing which network the device is in.
[0077] Turning to FIG. 9 , another graphical presentation 130 for display at the host 70 ( FIG. 1 ) is shown. 4 graphs are shown, one on top of each other with time being plotted on the x-axes. The top graph 131 plots a total hop count for the entire system which, as shown, averages about 72 or slightly less. An increase in the hop count would provide a warning to the operator. The other graphs in FIG. 9 provide environmental information from the environmental node 66 shown in FIG. 2 . The graph 132 provides a reading of barometric pressure; the graph 133 provides a reading of humidity; and the graph 134 provides a reading of the general RF background noise within the operating frequency band. Other environmental indications not presented in FIG. 9 could be temperature and rainfall.
[0078] Turning to FIG. 10 , it will be noted that many of the devices 80 - 85 shown in FIG. 2 would be HART field devices, and therefore the field node 68 will be sending a HART signal to either a repeater node 64 or directly to a conversion node 140 which, in the embodiment shown in FIG. 10 , may be a separate element or may comprise part of the base node 62 . A HART signal may also be sent from an environmental node 66 as shown. The conversion node 140 includes software to convert the HART signal to a different protocol, e.g., the EMBER protocol used with low-power wireless networking software and radio technology. See http://www.ember.com/. Of course, other protocols are available and will be apparent to those skilled in the art. The conversion node 140 converts the HART signal to an EMBER data packet at 141 . The data packet includes an origin indication 142 and a destination indication 143 which is determined by software either in the base node 62 or in the conversion node 140 . The HART message 144 is sandwiched between the origin data 142 and destination data 143 . The signal is then sent to a routing node 145 which determines, from the destination information 143 , which object device 146 to send the data to. The routing node 145 then transmits the data through one or more repeaters 64 and/or field nodes 68 to the object device 146 . One type of software that could be used to convert the field device signal from one protocol (HART) to another protocol is the JTS software sold by Acugen (http://www.acugen.com/jts.htm).
[0079] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A wireless communication system for use in a process environment uses mesh and possibly a combination of mesh and point-to-point communications to produce a wireless communication network that can be easily set up, configured, changed and monitored, thereby making a wireless communication network that is less expensive, and more robust and reliable. The wireless communication system allows virtual communication paths to be established and used within the process control system in a manner that is independent of the manner in which the wireless signals are sent between different wireless transmitting and receiving devices within the process plant. Still further, communication analysis tools are provided to enable a user or operator to view the operation of the wireless communication network to thereby analyze the ongoing operation of the wireless communications within the wireless communication network.
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